tor/ChangeLog

Changes in version 0.3.1.3-alpha - 2017-06-08
  Tor 0.3.1.3-alpha fixes a pair of bugs that would allow an attacker to
  remotely crash a hidden service with an assertion failure. Anyone
  running a hidden service should upgrade to this version, or to some
  other version with fixes for TROVE-2017-004 and TROVE-2017-005.

  Tor 0.3.1.3-alpha also includes fixes for several key management bugs
  that sometimes made relays unreliable, as well as several other
  bugfixes described below.

  o Major bugfixes (hidden service, relay, security):
    - Fix a remotely triggerable assertion failure when a hidden service
      handles a malformed BEGIN cell. Fixes bug 22493, tracked as
      TROVE-2017-004 and as CVE-2017-0375; bugfix on 0.3.0.1-alpha.
    - Fix a remotely triggerable assertion failure caused by receiving a
      BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
      22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
      on 0.2.2.1-alpha.

  o Major bugfixes (relay, link handshake):
    - When performing the v3 link handshake on a TLS connection, report
      that we have the x509 certificate that we actually used on that
      connection, even if we have changed certificates since that
      connection was first opened. Previously, we would claim to have
      used our most recent x509 link certificate, which would sometimes
      make the link handshake fail. Fixes one case of bug 22460; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (relays, key management):
    - Regenerate link and authentication certificates whenever the key
      that signs them changes; also, regenerate link certificates
      whenever the signed key changes. Previously, these processes were
      only weakly coupled, and we relays could (for minutes to hours)
      wind up with an inconsistent set of keys and certificates, which
      other relays would not accept. Fixes two cases of bug 22460;
      bugfix on 0.3.0.1-alpha.
    - When sending an Ed25519 signing->link certificate in a CERTS cell,
      send the certificate that matches the x509 certificate that we
      used on the TLS connection. Previously, there was a race condition
      if the TLS context rotated after we began the TLS handshake but
      before we sent the CERTS cell. Fixes a case of bug 22460; bugfix
      on 0.3.0.1-alpha.

  o Major bugfixes (torrc, crash):
    - Fix a crash bug when using %include in torrc. Fixes bug 22417;
      bugfix on 0.3.1.1-alpha. Patch by Daniel Pinto.

  o Minor features (code style):
    - Add "Falls through" comments to our codebase, in order to silence
      GCC 7's -Wimplicit-fallthrough warnings. Patch from Andreas
      Stieger. Closes ticket 22446.

  o Minor features (diagnostic):
    - Add logging messages to try to diagnose a rare bug that seems to
      generate RSA->Ed25519 cross-certificates dated in the 1970s. We
      think this is happening because of incorrect system clocks, but
      we'd like to know for certain. Diagnostic for bug 22466.

  o Minor bugfixes (correctness):
    - Avoid undefined behavior when parsing IPv6 entries from the geoip6
      file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.

  o Minor bugfixes (directory protocol):
    - Check for libzstd >= 1.1, because older versions lack the
      necessary streaming API. Fixes bug 22413; bugfix on 0.3.1.1-alpha.

  o Minor bugfixes (link handshake):
    - Lower the lifetime of the RSA->Ed25519 cross-certificate to six
      months, and regenerate it when it is within one month of expiring.
      Previously, we had generated this certificate at startup with a
      ten-year lifetime, but that could lead to weird behavior when Tor
      was started with a grossly inaccurate clock. Mitigates bug 22466;
      mitigation on 0.3.0.1-alpha.

  o Minor bugfixes (storage directories):
    - Always check for underflows in the cached storage directory usage.
      If the usage does underflow, re-calculate it. Also, avoid a
      separate underflow when the usage is not known. Fixes bug 22424;
      bugfix on 0.3.1.1-alpha.

  o Minor bugfixes (unit tests):
    - The unit tests now pass on systems where localhost is misconfigured
      to some IPv4 address other than 127.0.0.1. Fixes bug 6298; bugfix
      on 0.0.9pre2.

  o Documentation:
    - Clarify the manpage for the (deprecated) torify script. Closes
      ticket 6892.

Changes in version 0.3.0.8 - 2017-06-08
  Tor 0.3.0.8 fixes a pair of bugs that would allow an attacker to
  remotely crash a hidden service with an assertion failure. Anyone
  running a hidden service should upgrade to this version, or to some
  other version with fixes for TROVE-2017-004 and TROVE-2017-005.

  Tor 0.3.0.8 also includes fixes for several key management bugs
  that sometimes made relays unreliable, as well as several other
  bugfixes described below.

  o Major bugfixes (hidden service, relay, security, backport
    from 0.3.1.3-alpha):
    - Fix a remotely triggerable assertion failure when a hidden service
      handles a malformed BEGIN cell. Fixes bug 22493, tracked as
      TROVE-2017-004 and as CVE-2017-0375; bugfix on 0.3.0.1-alpha.
    - Fix a remotely triggerable assertion failure caused by receiving a
      BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
      22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
      on 0.2.2.1-alpha.

  o Major bugfixes (relay, link handshake, backport from 0.3.1.3-alpha):
    - When performing the v3 link handshake on a TLS connection, report
      that we have the x509 certificate that we actually used on that
      connection, even if we have changed certificates since that
      connection was first opened. Previously, we would claim to have
      used our most recent x509 link certificate, which would sometimes
      make the link handshake fail. Fixes one case of bug 22460; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (relays, key management, backport from 0.3.1.3-alpha):
    - Regenerate link and authentication certificates whenever the key
      that signs them changes; also, regenerate link certificates
      whenever the signed key changes. Previously, these processes were
      only weakly coupled, and we relays could (for minutes to hours)
      wind up with an inconsistent set of keys and certificates, which
      other relays would not accept. Fixes two cases of bug 22460;
      bugfix on 0.3.0.1-alpha.
    - When sending an Ed25519 signing->link certificate in a CERTS cell,
      send the certificate that matches the x509 certificate that we
      used on the TLS connection. Previously, there was a race condition
      if the TLS context rotated after we began the TLS handshake but
      before we sent the CERTS cell. Fixes a case of bug 22460; bugfix
      on 0.3.0.1-alpha.

  o Major bugfixes (hidden service v3, backport from 0.3.1.1-alpha):
    - Stop rejecting v3 hidden service descriptors because their size
      did not match an old padding rule. Fixes bug 22447; bugfix on
      tor-0.3.0.1-alpha.

  o Minor features (fallback directory list, backport from 0.3.1.3-alpha):
    - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
      December 2016 (of which ~126 were still functional) with a list of
      151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May
      2017. Resolves ticket 21564.

  o Minor bugfixes (configuration, backport from 0.3.1.1-alpha):
    - Do not crash when starting with LearnCircuitBuildTimeout 0. Fixes
      bug 22252; bugfix on 0.2.9.3-alpha.

  o Minor bugfixes (correctness, backport from 0.3.1.3-alpha):
    - Avoid undefined behavior when parsing IPv6 entries from the geoip6
      file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.

  o Minor bugfixes (link handshake, backport from 0.3.1.3-alpha):
    - Lower the lifetime of the RSA->Ed25519 cross-certificate to six
      months, and regenerate it when it is within one month of expiring.
      Previously, we had generated this certificate at startup with a
      ten-year lifetime, but that could lead to weird behavior when Tor
      was started with a grossly inaccurate clock. Mitigates bug 22466;
      mitigation on 0.3.0.1-alpha.

  o Minor bugfixes (memory leak, directory authority, backport from
    0.3.1.2-alpha):
    - When directory authorities reject a router descriptor due to
      keypinning, free the router descriptor rather than leaking the
      memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha.


Changes in version 0.2.9.11 - 2017-06-08
  Tor 0.2.9.11 backports a fix for a bug that would allow an attacker to
  remotely crash a hidden service with an assertion failure. Anyone
  running a hidden service should upgrade to this version, or to some
  other version with fixes for TROVE-2017-005. (Versions before 0.3.0
  are not affected by TROVE-2017-004.)

  Tor 0.2.9.11 also backports fixes for several key management bugs
  that sometimes made relays unreliable, as well as several other
  bugfixes described below.

  o Major bugfixes (hidden service, relay, security, backport
    from 0.3.1.3-alpha):
    - Fix a remotely triggerable assertion failure caused by receiving a
      BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
      22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
      on 0.2.2.1-alpha.

  o Major bugfixes (relay, link handshake, backport from 0.3.1.3-alpha):
    - When performing the v3 link handshake on a TLS connection, report
      that we have the x509 certificate that we actually used on that
      connection, even if we have changed certificates since that
      connection was first opened. Previously, we would claim to have
      used our most recent x509 link certificate, which would sometimes
      make the link handshake fail. Fixes one case of bug 22460; bugfix
      on 0.2.3.6-alpha.

  o Minor features (fallback directory list, backport from 0.3.1.3-alpha):
    - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
      December 2016 (of which ~126 were still functional) with a list of
      151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May
      2017. Resolves ticket 21564.

  o Minor features (future-proofing, backport from 0.3.0.7):
    - Tor no longer refuses to download microdescriptors or descriptors if
      they are listed as "published in the future".  This change will
      eventually allow us to stop listing meaningful "published" dates
      in microdescriptor consensuses, and thereby allow us to reduce the
      resources required to download consensus diffs by over 50%.
      Implements part of ticket 21642; implements part of proposal 275.

  o Minor features (directory authorities, backport from 0.3.0.4-rc)
    - Directory authorities now reject relays running versions
      0.2.9.1-alpha through 0.2.9.4-alpha, because those relays
      suffer from bug 20499 and don't keep their consensus cache
      up-to-date. Resolves ticket 20509.

  o Minor features (geoip):
    - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (control port, backport from 0.3.0.6):
    - The GETINFO extra-info/digest/<digest> command was broken because
      of a wrong base16 decode return value check, introduced when
      refactoring that API. Fixes bug 22034; bugfix on 0.2.9.1-alpha.

  o Minor bugfixes (correctness, backport from 0.3.1.3-alpha):
    - Avoid undefined behavior when parsing IPv6 entries from the geoip6
      file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.

  o Minor bugfixes (Linux seccomp2 sandbox, backport from 0.3.0.7):
    - The getpid() system call is now permitted under the Linux seccomp2
      sandbox, to avoid crashing with versions of OpenSSL (and other
      libraries) that attempt to learn the process's PID by using the
      syscall rather than the VDSO code. Fixes bug 21943; bugfix
      on 0.2.5.1-alpha.

  o Minor bugfixes (memory leak, directory authority, backport
    from 0.3.1.2-alpha):
    - When directory authorities reject a router descriptor due to
      keypinning, free the router descriptor rather than leaking the
      memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha.

Changes in version 0.2.8.14 - 2017-06-08
  Tor 0.2.7.8 backports a fix for a bug that would allow an attacker to
  remotely crash a hidden service with an assertion failure. Anyone
  running a hidden service should upgrade to this version, or to some
  other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
  are not affected by TROVE-2017-004.)

  o Major bugfixes (hidden service, relay, security):
    - Fix a remotely triggerable assertion failure caused by receiving a
      BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
      22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
      on 0.2.2.1-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
      Country database.

  o Minor features (fallback directory list, backport from 0.3.1.3-alpha):
    - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
      December 2016 (of which ~126 were still functional) with a list of
      151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May
      2017. Resolves ticket 21564.

  o Minor bugfixes (correctness):
    - Avoid undefined behavior when parsing IPv6 entries from the geoip6
      file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.

Changes in version 0.2.7.8 - 2017-06-08
  Tor 0.2.7.8 backports a fix for a bug that would allow an attacker to
  remotely crash a hidden service with an assertion failure. Anyone
  running a hidden service should upgrade to this version, or to some
  other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
  are not affected by TROVE-2017-004.)

  o Major bugfixes (hidden service, relay, security):
    - Fix a remotely triggerable assertion failure caused by receiving a
      BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
      22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
      on 0.2.2.1-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (correctness):
    - Avoid undefined behavior when parsing IPv6 entries from the geoip6
      file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.


Changes in version 0.2.6.12 - 2017-06-08
  Tor 0.2.6.12 backports a fix for a bug that would allow an attacker to
  remotely crash a hidden service with an assertion failure. Anyone
  running a hidden service should upgrade to this version, or to some
  other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
  are not affected by TROVE-2017-004.)

  o Major bugfixes (hidden service, relay, security):
    - Fix a remotely triggerable assertion failure caused by receiving a
      BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
      22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
      on 0.2.2.1-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (correctness):
    - Avoid undefined behavior when parsing IPv6 entries from the geoip6
      file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.

Changes in version 0.2.5.14 - 2017-06-08
  Tor 0.2.5.14 backports a fix for a bug that would allow an attacker to
  remotely crash a hidden service with an assertion failure. Anyone
  running a hidden service should upgrade to this version, or to some
  other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
  are not affected by TROVE-2017-004.)

  o Major bugfixes (hidden service, relay, security):
    - Fix a remotely triggerable assertion failure caused by receiving a
      BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
      22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
      on 0.2.2.1-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (correctness):
    - Avoid undefined behavior when parsing IPv6 entries from the geoip6
      file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.

Changes in version 0.2.4.29 - 2017-06-08
  Tor 0.2.4.29 backports a fix for a bug that would allow an attacker to
  remotely crash a hidden service with an assertion failure. Anyone
  running a hidden service should upgrade to this version, or to some
  other version with fixes for TROVE-2017-005.  (Versions before 0.3.0
  are not affected by TROVE-2017-004.)

  o Major bugfixes (hidden service, relay, security):
    - Fix a remotely triggerable assertion failure caused by receiving a
      BEGIN_DIR cell on a hidden service rendezvous circuit. Fixes bug
      22494, tracked as TROVE-2017-005 and CVE-2017-0376; bugfix
      on 0.2.2.1-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (correctness):
    - Avoid undefined behavior when parsing IPv6 entries from the geoip6
      file. Fixes bug 22490; bugfix on 0.2.4.6-alpha.


Changes in version 0.3.1.2-alpha - 2017-05-26
  Tor 0.3.1.2-alpha is the second release in the 0.3.1.x series. It
  fixes a few bugs found while testing 0.3.1.1-alpha, including a
  memory corruption bug that affected relay stability.

  o Major bugfixes (crash, relay):
    - Fix a memory-corruption bug in relays that set MyFamily.
      Previously, they would double-free MyFamily elements when making
      the next descriptor or when changing their configuration. Fixes
      bug 22368; bugfix on 0.3.1.1-alpha.

  o Minor bugfixes (logging):
    - Log a better message when a directory authority replies to an
      upload with an unexpected status code. Fixes bug 11121; bugfix
      on 0.1.0.1-rc.

  o Minor bugfixes (memory leak, directory authority):
    - When directory authorities reject a router descriptor due to
      keypinning, free the router descriptor rather than leaking the
      memory. Fixes bug 22370; bugfix on 0.2.7.2-alpha.


Changes in version 0.3.1.1-alpha - 2017-05-22
  Tor 0.3.1.1-alpha is the first release in the 0.3.1.x series. It
  reduces the bandwidth usage for Tor's directory protocol, adds some
  basic padding to resist netflow-based traffic analysis and to serve as
  the basis of other padding in the future, and adds rust support to the
  build system.

  It also contains numerous other small features and improvements to
  security, correctness, and performance.

  Below are the changes since 0.3.0.7.

  o Major features (directory protocol):
    - Tor relays and authorities can now serve clients an abbreviated
      version of the consensus document, containing only the changes
      since an older consensus document that the client holds. Clients
      now request these documents when available. When both client and
      server use this new protocol, they will use far less bandwidth (up
      to 94% less) to keep the client's consensus up-to-date. Implements
      proposal 140; closes ticket 13339. Based on work by Daniel Martí.
    - Tor can now compress directory traffic with lzma or with zstd
      compression algorithms, which can deliver better bandwidth
      performance. Because lzma is computationally expensive, it's only
      used for documents that can be compressed once and served many
      times. Support for these algorithms requires that tor is built
      with the libzstd and/or liblzma libraries available. Implements
      proposal 278; closes ticket 21662.
    - Relays now perform the more expensive compression operations, and
      consensus diff generation, in worker threads. This separation
      avoids delaying the main thread when a new consensus arrives.

  o Major features (experimental):
    - Tor can now build modules written in Rust. To turn this on, pass
      the "--enable-rust" flag to the configure script. It's not time to
      get excited yet: currently, there is no actual Rust functionality
      beyond some simple glue code, and a notice at startup to tell you
      that Rust is running. Still, we hope that programmers and
      packagers will try building Tor with Rust support, so that we can
      find issues and solve portability problems. Closes ticket 22106.

  o Major features (traffic analysis resistance):
    - Connections between clients and relays now send a padding cell in
      each direction every 1.5 to 9.5 seconds (tunable via consensus
      parameters). This padding will not resist specialized
      eavesdroppers, but it should be enough to make many ISPs' routine
      network flow logging less useful in traffic analysis against
      Tor users.

      Padding is negotiated using Tor's link protocol, so both relays
      and clients must upgrade for this to take effect. Clients may
      still send padding despite the relay's version by setting
      ConnectionPadding 1 in torrc, and may disable padding by setting
      ConnectionPadding 0 in torrc. Padding may be minimized for mobile
      users with the torrc option ReducedConnectionPadding. Implements
      Proposal 251 and Section 2 of Proposal 254; closes ticket 16861.
    - Relays will publish 24 hour totals of padding and non-padding cell
      counts to their extra-info descriptors, unless PaddingStatistics 0
      is set in torrc. These 24 hour totals are also rounded to
      multiples of 10000.

  o Major bugfixes (connection usage):
    - We use NETINFO cells to try to determine if both relays involved
      in a connection will agree on the canonical status of that
      connection. We prefer the connections where this is the case for
      extend cells, and try to close connections where relays disagree
      on their canonical status early. Also, we now prefer the oldest
      valid connection for extend cells. These two changes should reduce
      the number of long-term connections that are kept open between
      relays. Fixes bug 17604; bugfix on 0.2.5.5-alpha.
    - Relays now log hourly statistics (look for
      "channel_check_for_duplicates" lines) on the total number of
      connections to other relays. If the number of connections per
      relay is unexpectedly large, this log message is at notice level.
      Otherwise it is at info.

  o Major bugfixes (entry guards):
    - Don't block bootstrapping when a primary bridge is offline and we
      can't get its descriptor. Fixes bug 22325; fixes one case of bug
      21969; bugfix on 0.3.0.3-alpha.

  o Major bugfixes (linux TPROXY support):
    - Fix a typo that had prevented TPROXY-based transparent proxying
      from working under Linux. Fixes bug 18100; bugfix on 0.2.6.3-alpha.
      Patch from "d4fq0fQAgoJ".

  o Minor features (security, windows):
    - Enable a couple of pieces of Windows hardening: one
      (HeapEnableTerminationOnCorruption) that has been on-by-default
      since Windows 8, and unavailable before Windows 7; and one
      (PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION) which we believe doesn't
      affect us, but shouldn't do any harm. Closes ticket 21953.

  o Minor features (config options):
    - Allow "%include" directives in torrc configuration files. These
      directives import the settings from other files, or from all the
      files in a directory. Closes ticket 1922. Code by Daniel Pinto.
    - Make SAVECONF return an error when overwriting a torrc that has
      includes. Using SAVECONF with the FORCE option will allow it to
      overwrite torrc even if includes are used. Related to ticket 1922.
    - Add "GETINFO config-can-saveconf" to tell controllers if SAVECONF
      will work without the FORCE option. Related to ticket 1922.

  o Minor features (controller):
    - Warn the first time that a controller requests data in the long-
      deprecated 'GETINFO network-status' format. Closes ticket 21703.

  o Minor features (defaults):
    - The default value for UseCreateFast is now 0: clients which
      haven't yet received a consensus document will now use a proper
      ntor handshake to talk to their directory servers whenever they
      can. Closes ticket 21407.
    - Onion key rotation and expiry intervals are now defined as a
      network consensus parameter, per proposal 274. The default
      lifetime of an onion key is increased from 7 to 28 days. Old onion
      keys will expire after 7 days by default. This change will make
      consensus diffs much smaller, and save significant bandwidth.
      Closes ticket 21641.

  o Minor features (fallback directory list):
    - Update the fallback directory mirror whitelist and blacklist based
      on operator emails. Closes task 21121.
    - Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
      December 2016 (of which ~126 were still functional) with a list of
      151 fallbacks (32 new, 119 unchanged, 58 removed) generated in May
      2017. Resolves ticket 21564.

  o Minor features (hidden services, logging):
    - Log a message when a hidden service descriptor has fewer
      introduction points than specified in
      HiddenServiceNumIntroductionPoints. Closes tickets 21598.
    - Log a message when a hidden service reaches its introduction point
      circuit limit, and when that limit is reset. Follow up to ticket
      21594; closes ticket 21622.
    - Warn user if multiple entries in EntryNodes and at least one
      HiddenService are used together. Pinning EntryNodes along with a
      hidden service can be possibly harmful; for instance see ticket
      14917 or 21155. Closes ticket 21155.

  o Minor features (linux seccomp2 sandbox):
    - We now have a document storage backend compatible with the Linux
      seccomp2 sandbox. This backend is used for consensus documents and
      diffs between them; in the long term, we'd like to use it for
      unparseable directory material too. Closes ticket 21645
    - Increase the maximum allowed size passed to mprotect(PROT_WRITE)
      from 1MB to 16MB. This was necessary with the glibc allocator in
      order to allow worker threads to allocate more memory -- which in
      turn is necessary because of our new use of worker threads for
      compression. Closes ticket 22096.

  o Minor features (logging):
    - Log files are no longer created world-readable by default.
      (Previously, most distributors would store the logs in a non-
      world-readable location to prevent inappropriate access. This
      change is an extra precaution.) Closes ticket 21729; patch
      from toralf.

  o Minor features (performance):
    - Our Keccak (SHA-3) implementation now accesses memory more
      efficiently, especially on little-endian systems. Closes
      ticket 21737.
    - Add an O(1) implementation of channel_find_by_global_id(), to
      speed some controller functions.

  o Minor features (relay, configuration):
    - The MyFamily option may now be repeated as many times as desired,
      for relays that want to configure large families. Closes ticket
      4998; patch by Daniel Pinto.

  o Minor features (safety):
    - Add an explicit check to extrainfo_parse_entry_from_string() for
      NULL inputs. We don't believe this can actually happen, but it may
      help silence a warning from the Clang analyzer. Closes
      ticket 21496.

  o Minor features (testing):
    - Add a "--disable-memory-sentinels" feature to help with fuzzing.
      When Tor is compiled with this option, we disable a number of
      redundant memory-safety failsafes that are intended to stop bugs
      from becoming security issues. This makes it easier to hunt for
      bugs that would be security issues without the failsafes turned
      on. Closes ticket 21439.
    - Add a general event-tracing instrumentation support to Tor. This
      subsystem will enable developers and researchers to add fine-
      grained instrumentation to their Tor instances, for use when
      examining Tor network performance issues. There are no trace
      events yet, and event-tracing is off by default unless enabled at
      compile time. Implements ticket 13802.
    - Improve our version parsing tests: add tests for typical version
      components, add tests for invalid versions, including numeric
      range and non-numeric prefixes. Unit tests 21278, 21450, and
      21507. Partially implements 21470.

  o Minor bugfixes (bandwidth accounting):
    - Roll over monthly accounting at the configured hour and minute,
      rather than always at 00:00. Fixes bug 22245; bugfix on 0.0.9rc1.
      Found by Andrey Karpov with PVS-Studio.

  o Minor bugfixes (code correctness):
    - Accurately identify client connections by their lack of peer
      authentication. This means that we bail out earlier if asked to
      extend to a client. Follow-up to 21407. Fixes bug 21406; bugfix
      on 0.2.4.23.

  o Minor bugfixes (configuration):
    - Do not crash when starting with LearnCircuitBuildTimeout 0. Fixes
      bug 22252; bugfix on 0.2.9.3-alpha.

  o Minor bugfixes (connection lifespan):
    - Allow more control over how long TLS connections are kept open:
      unify CircuitIdleTimeout and PredictedPortsRelevanceTime into a
      single option called CircuitsAvailableTimeout. Also, allow the
      consensus to control the default values for both this preference
      and the lifespan of relay-to-relay connections. Fixes bug 17592;
      bugfix on 0.2.5.5-alpha.
    - Increase the initial circuit build timeout testing frequency, to
      help ensure that ReducedConnectionPadding clients finish learning
      a timeout before their orconn would expire. The initial testing
      rate was set back in the days of TAP and before the Tor Browser
      updater, when we had to be much more careful about new clients
      making lots of circuits. With this change, a circuit build timeout
      is learned in about 15-20 minutes, instead of 100-120 minutes.

  o Minor bugfixes (controller):
    - GETINFO onions/current and onions/detached no longer respond with
      551 on empty lists. Fixes bug 21329; bugfix on 0.2.7.1-alpha.
    - Trigger HS descriptor events on the control port when the client
      fails to pick a hidden service directory for a hidden service.
      This can happen if all the hidden service directories are in
      ExcludeNodes, or they have all been queried within the last 15
      minutes. Fixes bug 22042; bugfix on 0.2.5.2-alpha.

  o Minor bugfixes (directory authority):
    - When rejecting a router descriptor for running an obsolete version
      of Tor without ntor support, warn about the obsolete tor version,
      not the missing ntor key. Fixes bug 20270; bugfix on 0.2.9.3-alpha.
    - Prevent the shared randomness subsystem from asserting when
      initialized by a bridge authority with an incomplete configuration
      file. Fixes bug 21586; bugfix on 0.2.9.8.

  o Minor bugfixes (exit-side DNS):
    - Fix an untriggerable assertion that checked the output of a
      libevent DNS error, so that the assertion actually behaves as
      expected. Fixes bug 22244; bugfix on 0.2.0.20-rc. Found by Andrey
      Karpov using PVS-Studio.

  o Minor bugfixes (fallback directories):
    - Make the usage example in updateFallbackDirs.py actually work, and
      explain what it does. Fixes bug 22270; bugfix on 0.3.0.3-alpha.
    - Decrease the guard flag average required to be a fallback. This
      allows us to keep relays that have their guard flag removed when
      they restart. Fixes bug 20913; bugfix on 0.2.8.1-alpha.
    - Decrease the minimum number of fallbacks to 100. Fixes bug 20913;
      bugfix on 0.2.8.1-alpha.
    - Make sure fallback directory mirrors have the same address, port,
      and relay identity key for at least 30 days before they are
      selected. Fixes bug 20913; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (hidden services):
    - Stop printing a cryptic warning when a hidden service gets a
      request to connect to a virtual port that it hasn't configured.
      Fixes bug 16706; bugfix on 0.2.6.3-alpha.
    - Simplify hidden service descriptor creation by using an existing
      flag to check if an introduction point is established. Fixes bug
      21599; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (memory leak):
    - Fix a small memory leak at exit from the backtrace handler code.
      Fixes bug 21788; bugfix on 0.2.5.2-alpha. Patch from Daniel Pinto.

  o Minor bugfixes (protocol, logging):
    - Downgrade a log statement about unexpected relay cells from "bug"
      to "protocol warning", because there is at least one use case
      where it can be triggered by a buggy tor implementation. Fixes bug
      21293; bugfix on 0.1.1.14-alpha.

  o Minor bugfixes (testing):
    - Use unbuffered I/O for utility functions around the
      process_handle_t type. This fixes unit test failures reported on
      OpenBSD and FreeBSD. Fixes bug 21654; bugfix on 0.2.3.1-alpha.
    - Make display of captured unit test log messages consistent. Fixes
      bug 21510; bugfix on 0.2.9.3-alpha.
    - Make test-network.sh always call chutney's test-network.sh.
      Previously, this only worked on systems which had bash installed,
      due to some bash-specific code in the script. Fixes bug 19699;
      bugfix on 0.3.0.4-rc. Follow-up to ticket 21581.

  o Minor bugfixes (voting consistency):
    - Reject version numbers with non-numeric prefixes (such as +, -, or
      whitespace). Disallowing whitespace prevents differential version
      parsing between POSIX-based and Windows platforms. Fixes bug 21507
      and part of 21508; bugfix on 0.0.8pre1.

  o Minor bugfixes (windows, relay):
    - Resolve "Failure from drain_fd: No error" warnings on Windows
      relays. Fixes bug 21540; bugfix on 0.2.6.3-alpha.

  o Code simplification and refactoring:
    - Break up the 630-line function connection_dir_client_reached_eof()
      into a dozen smaller functions. This change should help
      maintainability and readability of the client directory code.
    - Isolate our use of the openssl headers so that they are only
      included from our crypto wrapper modules, and from tests that
      examine those modules' internals. Closes ticket 21841.
    - Simplify our API to launch directory requests, making it more
      extensible and less error-prone. Now it's easier to add extra
      headers to directory requests. Closes ticket 21646.
    - Our base64 decoding functions no longer overestimate the output
      space that they need when parsing unpadded inputs. Closes
      ticket 17868.
    - Remove unused "ROUTER_ADDED_NOTIFY_GENERATOR" internal value.
      Resolves ticket 22213.
    - The logic that directory caches use to spool request to clients,
      serving them one part at a time so as not to allocate too much
      memory, has been refactored for consistency. Previously there was
      a separate spooling implementation per type of spoolable data. Now
      there is one common spooling implementation, with extensible data
      types. Closes ticket 21651.
    - Tor's compression module now supports multiple backends. Part of
      the implementation for proposal 278; closes ticket 21663.

  o Documentation:
    - Clarify the behavior of the KeepAliveIsolateSOCKSAuth sub-option.
      Closes ticket 21873.
    - Correct documentation about the default DataDirectory value.
      Closes ticket 21151.
    - Document the default behavior of NumEntryGuards and
      NumDirectoryGuards correctly. Fixes bug 21715; bugfix
      on 0.3.0.1-alpha.
    - Document key=value pluggable transport arguments for Bridge lines
      in torrc. Fixes bug 20341; bugfix on 0.2.5.1-alpha.
    - Note that bandwidth-limiting options don't affect TCP headers or
      DNS. Closes ticket 17170.

  o Removed features (configuration options, all in ticket 22060):
    - These configuration options are now marked Obsolete, and no longer
      have any effect: AllowInvalidNodes, AllowSingleHopCircuits,
      AllowSingleHopExits, ExcludeSingleHopRelays, FastFirstHopPK,
      TLSECGroup, WarnUnsafeSocks. They were first marked as deprecated
      in 0.2.9.2-alpha and have now been removed. The previous default
      behavior is now always chosen; the previous (less secure) non-
      default behavior is now unavailable.
    - CloseHSClientCircuitsImmediatelyOnTimeout and
      CloseHSServiceRendCircuitsImmediatelyOnTimeout were deprecated in
      0.2.9.2-alpha and now have been removed. HS circuits never close
      on circuit build timeout; they have a longer timeout period.
    - {Control,DNS,Dir,Socks,Trans,NATD,OR}ListenAddress were deprecated
      in 0.2.9.2-alpha and now have been removed. Use the ORPort option
      (and others) to configure listen-only and advertise-only addresses.

  o Removed features (tools):
    - We've removed the tor-checkkey tool from src/tools. Long ago, we
      used it to help people detect RSA keys that were generated by
      versions of Debian affected by CVE-2008-0166. But those keys have
      been out of circulation for ages, and this tool is no longer
      required. Closes ticket 21842.


Changes in version 0.3.0.7 - 2017-05-15
  Tor 0.3.0.7 fixes a medium-severity security bug in earlier versions
  of Tor 0.3.0.x, where an attacker could cause a Tor relay process
  to exit. Relays running earlier versions of Tor 0.3.0.x should upgrade;
  clients are not affected.

  o Major bugfixes (hidden service directory, security):
    - Fix an assertion failure in the hidden service directory code, which
      could be used by an attacker to remotely cause a Tor relay process to
      exit. Relays running earlier versions of Tor 0.3.0.x should upgrade.
      should upgrade. This security issue is tracked as TROVE-2017-002.
      Fixes bug 22246; bugfix on 0.3.0.1-alpha.

  o Minor features:
    - Update geoip and geoip6 to the May 2 2017 Maxmind GeoLite2
      Country database.

  o Minor features (future-proofing):
    - Tor no longer refuses to download microdescriptors or descriptors
      if they are listed as "published in the future". This change will
      eventually allow us to stop listing meaningful "published" dates
      in microdescriptor consensuses, and thereby allow us to reduce the
      resources required to download consensus diffs by over 50%.
      Implements part of ticket 21642; implements part of proposal 275.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - The getpid() system call is now permitted under the Linux seccomp2
      sandbox, to avoid crashing with versions of OpenSSL (and other
      libraries) that attempt to learn the process's PID by using the
      syscall rather than the VDSO code. Fixes bug 21943; bugfix
      on 0.2.5.1-alpha.


Changes in version 0.3.0.6 - 2017-04-26
  Tor 0.3.0.6 is the first stable release of the Tor 0.3.0 series.

  With the 0.3.0 series, clients and relays now use Ed25519 keys to
  authenticate their link connections to relays, rather than the old
  RSA1024 keys that they used before. (Circuit crypto has been
  Curve25519-authenticated since 0.2.4.8-alpha.) We have also replaced
  the guard selection and replacement algorithm to behave more robustly
  in the presence of unreliable networks, and to resist guard-
  capture attacks.

  This series also includes numerous other small features and bugfixes,
  along with more groundwork for the upcoming hidden-services revamp.

  Per our stable release policy, we plan to support the Tor 0.3.0
  release series for at least the next nine months, or for three months
  after the first stable release of the 0.3.1 series: whichever is
  longer. If you need a release with long-term support, we recommend
  that you stay with the 0.2.9 series.

  Below are the changes since 0.3.0.5-rc. For a list of all changes
  since 0.2.9, see the ReleaseNotes file.

  o Minor features (geoip):
    - Update geoip and geoip6 to the April 4 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (control port):
    - The GETINFO extra-info/digest/<digest> command was broken because
      of a wrong base16 decode return value check, introduced when
      refactoring that API. Fixes bug 22034; bugfix on 0.2.9.1-alpha.

  o Minor bugfixes (crash prevention):
    - Fix a (currently untriggerable, but potentially dangerous) crash
      bug when base32-encoding inputs whose sizes are not a multiple of
      5. Fixes bug 21894; bugfix on 0.2.9.1-alpha.


Changes in version 0.3.0.5-rc - 2017-04-05
  Tor 0.3.0.5-rc fixes a few remaining bugs, large and small, in the
  0.3.0 release series.

  This is the second release candidate in the Tor 0.3.0 series, and has
  much fewer changes than the first. If we find no new bugs or
  regressions here, the first stable 0.3.0 release will be nearly
  identical to it.

  o Major bugfixes (crash, directory connections):
    - Fix a rare crash when sending a begin cell on a circuit whose
      linked directory connection had already been closed. Fixes bug
      21576; bugfix on 0.2.9.3-alpha. Reported by Alec Muffett.

  o Major bugfixes (guard selection):
    - Fix a guard selection bug where Tor would refuse to bootstrap in
      some cases if the user swapped a bridge for another bridge in
      their configuration file. Fixes bug 21771; bugfix on 0.3.0.1-alpha.
      Reported by "torvlnt33r".

  o Minor features (geoip):
    - Update geoip and geoip6 to the March 7 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfix (compilation):
    - Fix a warning when compiling hs_service.c. Previously, it had no
      exported symbols when compiled for libor.a, resulting in a
      compilation warning from clang. Fixes bug 21825; bugfix
      on 0.3.0.1-alpha.

  o Minor bugfixes (hidden services):
    - Make hidden services check for failed intro point connections,
      even when they have exceeded their intro point creation limit.
      Fixes bug 21596; bugfix on 0.2.7.2-alpha. Reported by Alec Muffett.
    - Make hidden services with 8 to 10 introduction points check for
      failed circuits immediately after startup. Previously, they would
      wait for 5 minutes before performing their first checks. Fixes bug
      21594; bugfix on 0.2.3.9-alpha. Reported by Alec Muffett.

  o Minor bugfixes (memory leaks):
    - Fix a memory leak when using GETCONF on a port option. Fixes bug
      21682; bugfix on 0.3.0.3-alpha.

  o Minor bugfixes (relay):
    - Avoid a double-marked-circuit warning that could happen when we
      receive DESTROY cells under heavy load. Fixes bug 20059; bugfix
      on 0.1.0.1-rc.

  o Minor bugfixes (tests):
    - Run the entry_guard_parse_from_state_full() test with the time set
      to a specific date. (The guard state that this test was parsing
      contained guards that had expired since the test was first
      written.) Fixes bug 21799; bugfix on 0.3.0.1-alpha.

  o Documentation:
    - Update the description of the directory server options in the
      manual page, to clarify that a relay no longer needs to set
      DirPort in order to be a directory cache. Closes ticket 21720.



Changes in version 0.2.8.13 - 2017-03-03
  Tor 0.2.8.13 backports a security fix from later Tor
  releases.  Anybody running Tor 0.2.8.12 or earlier should upgrade to this
  this release, if for some reason they cannot upgrade to a later
  release series, and if they build Tor with the --enable-expensive-hardening
  option.

  Note that support for Tor 0.2.8.x is ending next year: we will not issue
  any fixes for the Tor 0.2.8.x series after 1 Jan 2018.  If you need
  a Tor release series with longer-term support, we recommend Tor 0.2.9.x.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.


Changes in version 0.2.7.7 - 2017-03-03
  Tor 0.2.7.7 backports a number of security fixes from later Tor
  releases.  Anybody running Tor 0.2.7.6 or earlier should upgrade to
  this release, if for some reason they cannot upgrade to a later
  release series.

  Note that support for Tor 0.2.7.x is ending this year: we will not issue
  any fixes for the Tor 0.2.7.x series after 1 August 2017.  If you need
  a Tor release series with longer-term support, we recommend Tor 0.2.9.x.

  o Directory authority changes (backport from 0.2.8.5-rc):
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Directory authority changes (backport from 0.2.9.2-alpha):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Directory authority key updates (backport from 0.2.8.1-alpha):
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Major bugfixes (parsing, security, backport from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
    - Stop a crash that could occur when a client running with DNSPort
      received a query with multiple address types, and the first
      address type was not supported. Found and fixed by Scott Dial.
      Fixes bug 18710; bugfix on 0.2.5.4-alpha.
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (key management, backport from 0.2.8.3-alpha):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.


Changes in version 0.2.6.11 - 2017-03-03
  Tor 0.2.6.11 backports a number of security fixes from later Tor
  releases.  Anybody running Tor 0.2.6.10 or earlier should upgrade to
  this release, if for some reason they cannot upgrade to a later
  release series.

  Note that support for Tor 0.2.6.x is ending this year: we will not issue
  any fixes for the Tor 0.2.6.x series after 1 August 2017.  If you need
  a Tor release series with longer-term support, we recommend Tor 0.2.9.x.

  o Directory authority changes (backport from 0.2.8.5-rc):
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Directory authority changes (backport from 0.2.9.2-alpha):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Directory authority key updates (backport from 0.2.8.1-alpha):
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Major features (security fixes, backport from 0.2.9.4-alpha):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major bugfixes (parsing, security, backport from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
    - Stop a crash that could occur when a client running with DNSPort
      received a query with multiple address types, and the first
      address type was not supported. Found and fixed by Scott Dial.
      Fixes bug 18710; bugfix on 0.2.5.4-alpha.

  o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
    - Fix an error that could cause us to read 4 bytes before the
      beginning of an openssl string. This bug could be used to cause
      Tor to crash on systems with unusual malloc implementations, or
      systems with unusual hardening installed. Fixes bug 17404; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (guard selection, backport from 0.2.7.6):
    - Actually look at the Guard flag when selecting a new directory
      guard. When we implemented the directory guard design, we
      accidentally started treating all relays as if they have the Guard
      flag during guard selection, leading to weaker anonymity and worse
      performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
      by Mohsen Imani.

  o Major bugfixes (key management, backport from 0.2.8.3-alpha):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation, backport from 0.2.7.6):
    - Fix a compilation warning with Clang 3.6: Do not check the
      presence of an address which can never be NULL. Fixes bug 17781.


Changes in version 0.2.5.13 - 2017-03-03
  Tor 0.2.5.13 backports a number of security fixes from later Tor
  releases.  Anybody running Tor 0.2.5.13 or earlier should upgrade to
  this release, if for some reason they cannot upgrade to a later
  release series.

  Note that support for Tor 0.2.5.x is ending next year: we will not issue
  any fixes for the Tor 0.2.5.x series after 1 May 2018.  If you need
  a Tor release series with longer-term support, we recommend Tor 0.2.9.x.

  o Directory authority changes (backport from 0.2.8.5-rc):
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Directory authority changes (backport from 0.2.9.2-alpha):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Directory authority key updates (backport from 0.2.8.1-alpha):
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Major features (security fixes, backport from 0.2.9.4-alpha):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major bugfixes (parsing, security, backport from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major bugfixes (security, client, DNS proxy, backport from 0.2.8.3-alpha):
    - Stop a crash that could occur when a client running with DNSPort
      received a query with multiple address types, and the first
      address type was not supported. Found and fixed by Scott Dial.
      Fixes bug 18710; bugfix on 0.2.5.4-alpha.

  o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
    - Fix an error that could cause us to read 4 bytes before the
      beginning of an openssl string. This bug could be used to cause
      Tor to crash on systems with unusual malloc implementations, or
      systems with unusual hardening installed. Fixes bug 17404; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (guard selection, backport from 0.2.7.6):
    - Actually look at the Guard flag when selecting a new directory
      guard. When we implemented the directory guard design, we
      accidentally started treating all relays as if they have the Guard
      flag during guard selection, leading to weaker anonymity and worse
      performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
      by Mohsen Imani.

  o Major bugfixes (key management, backport from 0.2.8.3-alpha):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation, backport from 0.2.7.6):
    - Fix a compilation warning with Clang 3.6: Do not check the
      presence of an address which can never be NULL. Fixes bug 17781.

  o Minor bugfixes (crypto error-handling, backport from 0.2.7.2-alpha):
    - Check for failures from crypto_early_init, and refuse to continue.
      A previous typo meant that we could keep going with an
      uninitialized crypto library, and would have OpenSSL initialize
      its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
      when implementing ticket 4900. Patch by "teor".

  o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
    - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
      a client authorized hidden service. Fixes bug 15823; bugfix
      on 0.2.1.6-alpha.


Changes in version 0.2.4.28 - 2017-03-03
  Tor 0.2.4.28 backports a number of security fixes from later Tor
  releases.  Anybody running Tor 0.2.4.27 or earlier should upgrade to
  this release, if for some reason they cannot upgrade to a later
  release series.

  Note that support for Tor 0.2.4.x is ending soon: we will not issue
  any fixes for the Tor 0.2.4.x series after 1 August 2017.  If you need
  a Tor release series with long-term support, we recommend Tor 0.2.9.x.

  o Directory authority changes (backport from 0.2.8.5-rc):
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Directory authority changes (backport from 0.2.9.2-alpha):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Directory authority key updates (backport from 0.2.8.1-alpha):
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Major features (security fixes, backport from 0.2.9.4-alpha):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major bugfixes (parsing, security, backport from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Major bugfixes (security, correctness, backport from 0.2.7.4-rc):
    - Fix an error that could cause us to read 4 bytes before the
      beginning of an openssl string. This bug could be used to cause
      Tor to crash on systems with unusual malloc implementations, or
      systems with unusual hardening installed. Fixes bug 17404; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (security, pointers, backport from 0.2.8.2-alpha):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (dns proxy mode, crash, backport from 0.2.8.2-alpha):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (guard selection, backport from 0.2.7.6):
    - Actually look at the Guard flag when selecting a new directory
      guard. When we implemented the directory guard design, we
      accidentally started treating all relays as if they have the Guard
      flag during guard selection, leading to weaker anonymity and worse
      performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
      by Mohsen Imani.

  o Major bugfixes (key management, backport from 0.2.8.3-alpha):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (parsing, backported from 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (security, memory erasure, backport from 0.2.8.1-alpha):
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (bug-resistance, backport from 0.2.8.2-alpha):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (DoS-resistance, backport from 0.2.7.1-alpha):
    - Make it harder for attackers to overload hidden services with
      introductions, by blocking multiple introduction requests on the
      same circuit. Resolves ticket 15515.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation, backport from 0.2.7.6):
    - Fix a compilation warning with Clang 3.6: Do not check the
      presence of an address which can never be NULL. Fixes bug 17781.

  o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
    - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
      a client authorized hidden service. Fixes bug 15823; bugfix
      on 0.2.1.6-alpha.


Changes in version 0.3.0.4-rc - 2017-03-01
  Tor 0.3.0.4-rc fixes some remaining bugs, large and small, in the
  0.3.0 release series, and introduces a few reliability features to
  keep them from coming back.

  This is the first release candidate in the Tor 0.3.0 series. If we
  find no new bugs or regressions here, the first stable 0.3.0 release
  will be nearly identical to it.

  o Major bugfixes (bridges):
    - When the same bridge is configured multiple times with the same
      identity, but at different address:port combinations, treat those
      bridge instances as separate guards. This fix restores the ability
      of clients to configure the same bridge with multiple pluggable
      transports. Fixes bug 21027; bugfix on 0.3.0.1-alpha.

  o Major bugfixes (hidden service directory v3):
    - Stop crashing on a failed v3 hidden service descriptor lookup
      failure. Fixes bug 21471; bugfixes on tor-0.3.0.1-alpha.

  o Major bugfixes (parsing):
    - When parsing a malformed content-length field from an HTTP
      message, do not read off the end of the buffer. This bug was a
      potential remote denial-of-service attack against Tor clients and
      relays. A workaround was released in October 2016, to prevent this
      bug from crashing Tor. This is a fix for the underlying issue,
      which should no longer matter (if you applied the earlier patch).
      Fixes bug 20894; bugfix on 0.2.0.16-alpha. Bug found by fuzzing
      using AFL (http://lcamtuf.coredump.cx/afl/).
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor feature (protocol versioning):
    - Add new protocol version for proposal 224. HSIntro now advertises
      version "3-4" and HSDir version "1-2". Fixes ticket 20656.

  o Minor features (directory authorities):
    - Directory authorities now reject descriptors that claim to be
      malformed versions of Tor. Helps prevent exploitation of
      bug 21278.
    - Reject version numbers with components that exceed INT32_MAX.
      Otherwise 32-bit and 64-bit platforms would behave inconsistently.
      Fixes bug 21450; bugfix on 0.0.8pre1.
    - Directory authorities now reject relays running versions
      0.2.9.1-alpha through 0.2.9.4-alpha, because those relays
      suffer from bug 20499 and don't keep their consensus cache
      up-to-date. Resolves ticket 20509.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor features (reliability, crash):
    - Try better to detect problems in buffers where they might grow (or
      think they have grown) over 2 GB in size. Diagnostic for
      bug 21369.

  o Minor features (testing):
    - During 'make test-network-all', if tor logs any warnings, ask
      chutney to output them. Requires a recent version of chutney with
      the 21572 patch. Implements 21570.

  o Minor bugfixes (certificate expiration time):
    - Avoid using link certificates that don't become valid till some
      time in the future. Fixes bug 21420; bugfix on 0.2.4.11-alpha

  o Minor bugfixes (code correctness):
    - Repair a couple of (unreachable or harmless) cases of the risky
      comparison-by-subtraction pattern that caused bug 21278.
    - Remove a redundant check for the UseEntryGuards option from the
      options_transition_affects_guards() function. Fixes bug 21492;
      bugfix on 0.3.0.1-alpha.

  o Minor bugfixes (directory mirrors):
    - Allow relays to use directory mirrors without a DirPort: these
      relays need to be contacted over their ORPorts using a begindir
      connection. Fixes one case of bug 20711; bugfix on 0.2.8.2-alpha.
    - Clarify the message logged when a remote relay is unexpectedly
      missing an ORPort or DirPort: users were confusing this with a
      local port. Fixes another case of bug 20711; bugfix
      on 0.2.8.2-alpha.

  o Minor bugfixes (guards):
    - Don't warn about a missing guard state on timeout-measurement
      circuits: they aren't supposed to be using guards. Fixes an
      instance of bug 21007; bugfix on 0.3.0.1-alpha.
    - Silence a BUG() warning when attempting to use a guard whose
      descriptor we don't know, and make this scenario less likely to
      happen. Fixes bug 21415; bugfix on 0.3.0.1-alpha.

  o Minor bugfixes (hidden service):
    - Pass correct buffer length when encoding legacy ESTABLISH_INTRO
      cells. Previously, we were using sizeof() on a pointer, instead of
      the real destination buffer. Fortunately, that value was only used
      to double-check that there was enough room--which was already
      enforced elsewhere. Fixes bug 21553; bugfix on 0.3.0.1-alpha.

  o Minor bugfixes (testing):
    - Fix Raspbian build issues related to missing socket errno in
      test_util.c. Fixes bug 21116; bugfix on tor-0.2.8.2. Patch
      by "hein".
    - Rename "make fuzz" to "make test-fuzz-corpora", since it doesn't
      actually fuzz anything. Fixes bug 21447; bugfix on 0.3.0.3-alpha.
    - Use bash in src/test/test-network.sh. This ensures we reliably
      call chutney's newer tools/test-network.sh when available. Fixes
      bug 21562; bugfix on 0.2.9.1-alpha.

  o Documentation:
    - Small fixes to the fuzzing documentation. Closes ticket 21472.


Changes in version 0.2.9.10 - 2017-03-01
  Tor 0.2.9.10 backports a security fix from later Tor release.  It also
  includes fixes for some major issues affecting directory authorities,
  LibreSSL compatibility, and IPv6 correctness.

  The Tor 0.2.9.x release series is now marked as a long-term-support
  series.  We intend to backport security fixes to 0.2.9.x until at
  least January of 2020.

  o Major bugfixes (directory authority, 0.3.0.3-alpha):
    - During voting, when marking a relay as a probable sybil, do not
      clear its BadExit flag: sybils can still be bad in other ways
      too. (We still clear the other flags.) Fixes bug 21108; bugfix
      on 0.2.0.13-alpha.

  o Major bugfixes (IPv6 Exits, backport from 0.3.0.3-alpha):
    - Stop rejecting all IPv6 traffic on Exits whose exit policy rejects
      any IPv6 addresses. Instead, only reject a port over IPv6 if the
      exit policy rejects that port on more than an IPv6 /16 of
      addresses. This bug was made worse by 17027 in 0.2.8.1-alpha,
      which rejected a relay's own IPv6 address by default. Fixes bug
      21357; bugfix on commit 004f3f4e53 in 0.2.4.7-alpha.

  o Major bugfixes (parsing, also in 0.3.0.4-rc):
    - Fix an integer underflow bug when comparing malformed Tor
      versions. This bug could crash Tor when built with
      --enable-expensive-hardening, or on Tor 0.2.9.1-alpha through Tor
      0.2.9.8, which were built with -ftrapv by default. In other cases
      it was harmless. Part of TROVE-2017-001. Fixes bug 21278; bugfix
      on 0.0.8pre1. Found by OSS-Fuzz.

  o Minor features (directory authorities, also in 0.3.0.4-rc):
    - Directory authorities now reject descriptors that claim to be
      malformed versions of Tor. Helps prevent exploitation of
      bug 21278.
    - Reject version numbers with components that exceed INT32_MAX.
      Otherwise 32-bit and 64-bit platforms would behave inconsistently.
      Fixes bug 21450; bugfix on 0.0.8pre1.

  o Minor features (geoip):
    - Update geoip and geoip6 to the February 8 2017 Maxmind GeoLite2
      Country database.

  o Minor features (portability, compilation, backport from 0.3.0.3-alpha):
    - Autoconf now checks to determine if OpenSSL structures are opaque,
      instead of explicitly checking for OpenSSL version numbers. Part
      of ticket 21359.
    - Support building with recent LibreSSL code that uses opaque
      structures. Closes ticket 21359.

  o Minor bugfixes (code correctness, also in 0.3.0.4-rc):
    - Repair a couple of (unreachable or harmless) cases of the risky
      comparison-by-subtraction pattern that caused bug 21278.

  o Minor bugfixes (tor-resolve, backport from 0.3.0.3-alpha):
    - The tor-resolve command line tool now rejects hostnames over 255
      characters in length. Previously, it would silently truncate them,
      which could lead to bugs. Fixes bug 21280; bugfix on 0.0.9pre5.
      Patch by "junglefowl".


Changes in version 0.3.0.3-alpha - 2017-02-03
  Tor 0.3.0.3-alpha fixes a few significant bugs introduced over the
  0.3.0.x development series, including some that could cause
  authorities to behave badly. There is also a fix for a longstanding
  bug that could prevent IPv6 exits from working. Tor 0.3.0.3-alpha also
  includes some smaller features and bugfixes.

  The Tor 0.3.0.x release series is now in patch-freeze: no additional
  features will be considered for inclusion in 0.3.0.x. We suspect that
  some bugs will probably remain, however, and we encourage people to
  test this release.

  o Major bugfixes (directory authority):
    - During voting, when marking a relay as a probable sybil, do not
      clear its BadExit flag: sybils can still be bad in other ways
      too. (We still clear the other flags.) Fixes bug 21108; bugfix
      on 0.2.0.13-alpha.
    - When deciding whether we have just found a router to be reachable,
      do not penalize it for not having performed an Ed25519 link
      handshake if it does not claim to support an Ed25519 handshake.
      Previously, we would treat such relays as non-running. Fixes bug
      21107; bugfix on 0.3.0.1-alpha.

  o Major bugfixes (entry guards):
    - Stop trying to build circuits through entry guards for which we
      have no descriptor. Also, stop crashing in the case that we *do*
      accidentally try to build a circuit in such a state. Fixes bug
      21242; bugfix on 0.3.0.1-alpha.

  o Major bugfixes (IPv6 Exits):
    - Stop rejecting all IPv6 traffic on Exits whose exit policy rejects
      any IPv6 addresses. Instead, only reject a port over IPv6 if the
      exit policy rejects that port on more than an IPv6 /16 of
      addresses. This bug was made worse by 17027 in 0.2.8.1-alpha,
      which rejected a relay's own IPv6 address by default. Fixes bug
      21357; bugfix on commit 004f3f4e53 in 0.2.4.7-alpha.

  o Minor feature (client):
    - Enable IPv6 traffic on the SocksPort by default. To disable this,
      a user will have to specify "NoIPv6Traffic". Closes ticket 21269.

  o Minor feature (fallback scripts):
    - Add a check_existing mode to updateFallbackDirs.py, which checks
      if fallbacks in the hard-coded list are working. Closes ticket
      20174. Patch by haxxpop.

  o Minor features (ciphersuite selection):
    - Clients now advertise a list of ciphersuites closer to the ones
      preferred by Firefox. Closes part of ticket 15426.
    - Allow relays to accept a wider range of ciphersuites, including
      chacha20-poly1305 and AES-CCM. Closes the other part of 15426.

  o Minor features (controller, configuration):
    - Each of the *Port options, such as SocksPort, ORPort, ControlPort,
      and so on, now comes with a __*Port variant that will not be saved
      to the torrc file by the controller's SAVECONF command. This
      change allows TorBrowser to set up a single-use domain socket for
      each time it launches Tor. Closes ticket 20956.
    - The GETCONF command can now query options that may only be
      meaningful in context-sensitive lists. This allows the controller
      to query the mixed SocksPort/__SocksPort style options introduced
      in feature 20956. Implements ticket 21300.

  o Minor features (portability, compilation):
    - Autoconf now checks to determine if OpenSSL structures are opaque,
      instead of explicitly checking for OpenSSL version numbers. Part
      of ticket 21359.
    - Support building with recent LibreSSL code that uses opaque
      structures. Closes ticket 21359.

  o Minor features (relay):
    - We now allow separation of exit and relay traffic to different
      source IP addresses, using the OutboundBindAddressExit and
      OutboundBindAddressOR options respectively. Closes ticket 17975.
      Written by Michael Sonntag.

  o Minor bugfix (logging):
    - Don't recommend the use of Tor2web in non-anonymous mode.
      Recommending Tor2web is a bad idea because the client loses all
      anonymity. Tor2web should only be used in specific cases by users
      who *know* and understand the issues. Fixes bug 21294; bugfix
      on 0.2.9.3-alpha.

  o Minor bugfixes (client):
    - Always recover from failures in extend_info_from_node(), in an
      attempt to prevent any recurrence of bug 21242. Fixes bug 21372;
      bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (client, entry guards):
    - Fix a bug warning (with backtrace) when we fail a channel that
      circuits to fallback directories on it. Fixes bug 21128; bugfix
      on 0.3.0.1-alpha.
    - Fix a spurious bug warning (with backtrace) when removing an
      expired entry guard. Fixes bug 21129; bugfix on 0.3.0.1-alpha.
    - Fix a bug of the new guard algorithm where tor could stall for up
      to 10 minutes before retrying a guard after a long period of no
      network. Fixes bug 21052; bugfix on 0.3.0.1-alpha.
    - Do not try to build circuits until we have descriptors for our
      primary entry guards. Related to fix for bug 21242.

  o Minor bugfixes (configure, autoconf):
    - Rename the configure option --enable-expensive-hardening to
      --enable-fragile-hardening. Expensive hardening makes the tor
      daemon abort when some kinds of issues are detected. Thus, it
      makes tor more at risk of remote crashes but safer against RCE or
      heartbleed bug category. We now try to explain this issue in a
      message from the configure script. Fixes bug 21290; bugfix
      on 0.2.5.4-alpha.

  o Minor bugfixes (controller):
    - Restore the (deprecated) DROPGUARDS controller command. Fixes bug
      20824; bugfix on 0.3.0.1-alpha.

  o Minor bugfixes (hidden service):
    - Clean up the code for expiring intro points with no associated
      circuits. It was causing, rarely, a service with some expiring
      introduction points to not open enough additional introduction
      points. Fixes part of bug 21302; bugfix on 0.2.7.2-alpha.
    - Stop setting the torrc option HiddenServiceStatistics to "0" just
      because we're not a bridge or relay. Instead, we preserve whatever
      value the user set (or didn't set). Fixes bug 21150; bugfix
      on 0.2.6.2-alpha.
    - Resolve two possible underflows which could lead to creating and
      closing a lot of introduction point circuits in a non-stop loop.
      Fixes bug 21302; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (portability):
    - Use "OpenBSD" compiler macro instead of "OPENBSD" or "__OpenBSD__".
      It is supported by OpenBSD itself, and also by most OpenBSD
      variants (such as Bitrig). Fixes bug 20980; bugfix
      on 0.1.2.1-alpha.
    - When mapping a file of length greater than SIZE_MAX, do not
      silently truncate its contents. This issue could occur on 32 bit
      systems with large file support and files which are larger than 4
      GB. Fixes bug 21134; bugfix on 0.3.0.1-alpha.

  o Minor bugfixes (tor-resolve):
    - The tor-resolve command line tool now rejects hostnames over 255
      characters in length. Previously, it would silently truncate them,
      which could lead to bugs. Fixes bug 21280; bugfix on 0.0.9pre5.
      Patch by "junglefowl".

  o Minor bugfixes (Windows services):
    - Be sure to initialize the monotonic time subsystem before using
      it, even when running as an NT service. Fixes bug 21356; bugfix
      on 0.2.9.1-alpha.


Changes in version 0.3.0.2-alpha - 2017-01-23
  Tor 0.3.0.2-alpha fixes a denial-of-service bug where an attacker could
  cause relays and clients to crash, even if they were not built with
  the --enable-expensive-hardening option. This bug affects all 0.2.9.x
  versions, and also affects 0.3.0.1-alpha: all relays running an affected
  version should upgrade.

  Tor 0.3.0.2-alpha also improves how exit relays and clients handle DNS
  time-to-live values, makes directory authorities enforce the 1-to-1
  mapping of relay RSA identity keys to ED25519 identity keys, fixes a
  client-side onion service reachability bug, does better at selecting
  the set of fallback directories, and more.

  o Major bugfixes (security, also in 0.2.9.9):
    - Downgrade the "-ftrapv" option from "always on" to "only on when
      --enable-expensive-hardening is provided."  This hardening option, like
      others, can turn survivable bugs into crashes--and having it on by
      default made a (relatively harmless) integer overflow bug into a
      denial-of-service bug. Fixes bug 21278 (TROVE-2017-001); bugfix on
      0.2.9.1-alpha.

  o Major features (security):
    - Change the algorithm used to decide DNS TTLs on client and server
      side, to better resist DNS-based correlation attacks like the
      DefecTor attack of Greschbach, Pulls, Roberts, Winter, and
      Feamster. Now relays only return one of two possible DNS TTL
      values, and clients are willing to believe DNS TTL values up to 3
      hours long. Closes ticket 19769.

  o Major features (directory authority, security):
    - The default for AuthDirPinKeys is now 1: directory authorities
      will reject relays where the RSA identity key matches a previously
      seen value, but the Ed25519 key has changed. Closes ticket 18319.

  o Major bugfixes (client, guard, crash):
    - In circuit_get_global_origin_list(), return the actual list of
      origin circuits. The previous version of this code returned the
      list of all the circuits, and could have caused strange bugs,
      including possible crashes. Fixes bug 21118; bugfix
      on 0.3.0.1-alpha.

  o Major bugfixes (client, onion service, also in 0.2.9.9):
    - Fix a client-side onion service reachability bug, where multiple
      socks requests to an onion service (or a single slow request)
      could cause us to mistakenly mark some of the service's
      introduction points as failed, and we cache that failure so
      eventually we run out and can't reach the service. Also resolves a
      mysterious "Remote server sent bogus reason code 65021" log
      warning. The bug was introduced in ticket 17218, where we tried to
      remember the circuit end reason as a uint16_t, which mangled
      negative values. Partially fixes bug 21056 and fixes bug 20307;
      bugfix on 0.2.8.1-alpha.

  o Major bugfixes (DNS):
    - Fix a bug that prevented exit nodes from caching DNS records for
      more than 60 seconds. Fixes bug 19025; bugfix on 0.2.4.7-alpha.

  o Minor features (controller):
    - Add "GETINFO sr/current" and "GETINFO sr/previous" keys, to expose
      shared-random values to the controller. Closes ticket 19925.

  o Minor features (entry guards):
    - Add UseEntryGuards to TEST_OPTIONS_DEFAULT_VALUES in order to not
      break regression tests.
    - Require UseEntryGuards when UseBridges is set, in order to make
      sure bridges aren't bypassed. Resolves ticket 20502.

  o Minor features (fallback directories):
    - Select 200 fallback directories for each release. Closes
      ticket 20881.
    - Allow 3 fallback relays per operator, which is safe now that we
      are choosing 200 fallback relays. Closes ticket 20912.
    - Exclude relays affected by bug 20499 from the fallback list.
      Exclude relays from the fallback list if they are running versions
      known to be affected by bug 20499, or if in our tests they deliver
      a stale consensus (i.e. one that expired more than 24 hours ago).
      Closes ticket 20539.
    - Reduce the minimum fallback bandwidth to 1 MByte/s. Part of
      ticket 18828.
    - Require fallback directories to have the same address and port for
      7 days (now that we have enough relays with this stability).
      Relays whose OnionOO stability timer is reset on restart by bug
      18050 should upgrade to Tor 0.2.8.7 or later, which has a fix for
      this issue. Closes ticket 20880; maintains short-term fix
      in 0.2.8.2-alpha.
    - Require fallbacks to have flags for 90% of the time (weighted
      decaying average), rather than 95%. This allows at least 73% of
      clients to bootstrap in the first 5 seconds without contacting an
      authority. Part of ticket 18828.
    - Annotate updateFallbackDirs.py with the bandwidth and consensus
      weight for each candidate fallback. Closes ticket 20878.
    - Make it easier to change the output sort order of fallbacks.
      Closes ticket 20822.
    - Display the relay fingerprint when downloading consensuses from
      fallbacks. Closes ticket 20908.

  o Minor features (geoip, also in 0.2.9.9):
    - Update geoip and geoip6 to the January 4 2017 Maxmind GeoLite2
      Country database.

  o Minor features (next-gen onion service directories):
    - Remove the "EnableOnionServicesV3" consensus parameter that we
      introduced in 0.3.0.1-alpha: relays are now always willing to act
      as v3 onion service directories. Resolves ticket 19899.

  o Minor features (linting):
    - Enhance the changes file linter to warn on Tor versions that are
      prefixed with "tor-". Closes ticket 21096.

  o Minor features (logging):
    - In several places, describe unset ed25519 keys as "<unset>",
      rather than the scary "AAAAAAAA...AAA". Closes ticket 21037.

  o Minor bugfix (control protocol):
    - The reply to a "GETINFO config/names" request via the control
      protocol now spells the type "Dependent" correctly. This is a
      breaking change in the control protocol. (The field seems to be
      ignored by the most common known controllers.) Fixes bug 18146;
      bugfix on 0.1.1.4-alpha.

  o Minor bugfixes (bug resilience):
    - Fix an unreachable size_t overflow in base64_decode(). Fixes bug
      19222; bugfix on 0.2.0.9-alpha. Found by Guido Vranken; fixed by
      Hans Jerry Illikainen.

  o Minor bugfixes (build):
    - Replace obsolete Autoconf macros with their modern equivalent and
      prevent similar issues in the future. Fixes bug 20990; bugfix
      on 0.1.0.1-rc.

  o Minor bugfixes (client, guards):
    - Fix bug where Tor would think that there are circuits waiting for
      better guards even though those circuits have been freed. Fixes
      bug 21142; bugfix on 0.3.0.1-alpha.

  o Minor bugfixes (config):
    - Don't assert on startup when trying to get the options list and
      LearnCircuitBuildTimeout is set to 0: we are currently parsing the
      options so of course they aren't ready yet. Fixes bug 21062;
      bugfix on 0.2.9.3-alpha.

  o Minor bugfixes (controller):
    - Make the GETINFO interface for inquiring about entry guards
      support the new guards backend. Fixes bug 20823; bugfix
      on 0.3.0.1-alpha.

  o Minor bugfixes (dead code):
    - Remove a redundant check for PidFile changes at runtime in
      options_transition_allowed(): this check is already performed
      regardless of whether the sandbox is active. Fixes bug 21123;
      bugfix on 0.2.5.4-alpha.

  o Minor bugfixes (documentation):
    - Update the tor manual page to document every option that can not
      be changed while tor is running. Fixes bug 21122.

  o Minor bugfixes (fallback directories):
    - Stop failing when a relay has no uptime data in
      updateFallbackDirs.py. Fixes bug 20945; bugfix on 0.2.8.1-alpha.
    - Avoid checking fallback candidates' DirPorts if they are down in
      OnionOO. When a relay operator has multiple relays, this
      prioritizes relays that are up over relays that are down. Fixes
      bug 20926; bugfix on 0.2.8.3-alpha.
    - Stop failing when OUTPUT_COMMENTS is True in updateFallbackDirs.py.
      Fixes bug 20877; bugfix on 0.2.8.3-alpha.

  o Minor bugfixes (guards, bootstrapping):
    - When connecting to a directory guard during bootstrap, do not mark
      the guard as successful until we receive a good-looking directory
      response from it. Fixes bug 20974; bugfix on 0.3.0.1-alpha.

  o Minor bugfixes (onion services):
    - Fix the config reload pruning of old vs new services so it
      actually works when both ephemeral and non-ephemeral services are
      configured. Fixes bug 21054; bugfix on 0.3.0.1-alpha.
    - Allow the number of introduction points to be as low as 0, rather
      than as low as 3. Fixes bug 21033; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (IPv6):
    - Make IPv6-using clients try harder to find an IPv6 directory
      server. Fixes bug 20999; bugfix on 0.2.8.2-alpha.
    - When IPv6 addresses have not been downloaded yet (microdesc
      consensus documents don't list relay IPv6 addresses), use hard-
      coded addresses for authorities, fallbacks, and configured
      bridges. Now IPv6-only clients can use microdescriptors. Fixes bug
      20996; bugfix on b167e82 from 19608 in 0.2.8.5-alpha.

  o Minor bugfixes (memory leaks):
    - Fix a memory leak when configuring hidden services. Fixes bug
      20987; bugfix on 0.3.0.1-alpha.

  o Minor bugfixes (portability, also in 0.2.9.9):
    - Avoid crashing when Tor is built using headers that contain
      CLOCK_MONOTONIC_COARSE, but then tries to run on an older kernel
      without CLOCK_MONOTONIC_COARSE. Fixes bug 21035; bugfix
      on 0.2.9.1-alpha.
    - Fix Libevent detection on platforms without Libevent 1 headers
      installed. Fixes bug 21051; bugfix on 0.2.9.1-alpha.

  o Minor bugfixes (relay):
    - Honor DataDirectoryGroupReadable when tor is a relay. Previously,
      initializing the keys would reset the DataDirectory to 0700
      instead of 0750 even if DataDirectoryGroupReadable was set to 1.
      Fixes bug 19953; bugfix on 0.0.2pre16. Patch by "redfish".

  o Minor bugfixes (testing):
    - Remove undefined behavior from the backtrace generator by removing
      its signal handler. Fixes bug 21026; bugfix on 0.2.5.2-alpha.

  o Minor bugfixes (unit tests):
    - Allow the unit tests to pass even when DNS lookups of bogus
      addresses do not fail as expected. Fixes bug 20862 and 20863;
      bugfix on unit tests introduced in 0.2.8.1-alpha
      through 0.2.9.4-alpha.

  o Code simplification and refactoring:
    - Refactor code to manipulate global_origin_circuit_list into
      separate functions. Closes ticket 20921.

  o Documentation (formatting):
    - Clean up formatting of tor.1 man page and HTML doc, where <pre>
      blocks were incorrectly appearing. Closes ticket 20885.

  o Documentation (man page):
    - Clarify many options in tor.1 and add some min/max values for
      HiddenService options. Closes ticket 21058.


Changes in version 0.2.9.9 - 2017-01-23
  Tor 0.2.9.9 fixes a denial-of-service bug where an attacker could
  cause relays and clients to crash, even if they were not built with
  the --enable-expensive-hardening option. This bug affects all 0.2.9.x
  versions, and also affects 0.3.0.1-alpha: all relays running an affected
  version should upgrade.

  This release also resolves a client-side onion service reachability
  bug, and resolves a pair of small portability issues.

  o Major bugfixes (security):
    - Downgrade the "-ftrapv" option from "always on" to "only on when
      --enable-expensive-hardening is provided." This hardening option,
      like others, can turn survivable bugs into crashes -- and having
      it on by default made a (relatively harmless) integer overflow bug
      into a denial-of-service bug. Fixes bug 21278 (TROVE-2017-001);
      bugfix on 0.2.9.1-alpha.

  o Major bugfixes (client, onion service):
    - Fix a client-side onion service reachability bug, where multiple
      socks requests to an onion service (or a single slow request)
      could cause us to mistakenly mark some of the service's
      introduction points as failed, and we cache that failure so
      eventually we run out and can't reach the service. Also resolves a
      mysterious "Remote server sent bogus reason code 65021" log
      warning. The bug was introduced in ticket 17218, where we tried to
      remember the circuit end reason as a uint16_t, which mangled
      negative values. Partially fixes bug 21056 and fixes bug 20307;
      bugfix on 0.2.8.1-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the January 4 2017 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (portability):
    - Avoid crashing when Tor is built using headers that contain
      CLOCK_MONOTONIC_COARSE, but then tries to run on an older kernel
      without CLOCK_MONOTONIC_COARSE. Fixes bug 21035; bugfix
      on 0.2.9.1-alpha.
    - Fix Libevent detection on platforms without Libevent 1 headers
      installed. Fixes bug 21051; bugfix on 0.2.9.1-alpha.


Changes in version 0.3.0.1-alpha - 2016-12-19
  Tor 0.3.0.1-alpha is the first alpha release in the 0.3.0 development
  series. It strengthens Tor's link and circuit handshakes by
  identifying relays by their Ed25519 keys, improves the algorithm that
  clients use to choose and maintain their list of guards, and includes
  additional backend support for the next-generation hidden service
  design. It also contains numerous other small features and
  improvements to security, correctness, and performance.

  Below are the changes since 0.2.9.8.

  o Major features (guard selection algorithm):
    - Tor's guard selection algorithm has been redesigned from the
      ground up, to better support unreliable networks and restrictive
      sets of entry nodes, and to better resist guard-capture attacks by
      hostile local networks. Implements proposal 271; closes
      ticket 19877.

  o Major features (next-generation hidden services):
    - Relays can now handle v3 ESTABLISH_INTRO cells as specified by
      prop224 aka "Next Generation Hidden Services". Service and clients
      don't use this functionality yet. Closes ticket 19043. Based on
      initial code by Alec Heifetz.
    - Relays now support the HSDir version 3 protocol, so that they can
      can store and serve v3 descriptors. This is part of the next-
      generation onion service work detailled in proposal 224. Closes
      ticket 17238.

  o Major features (protocol, ed25519 identity keys):
    - Relays now use Ed25519 to prove their Ed25519 identities and to
      one another, and to clients. This algorithm is faster and more
      secure than the RSA-based handshake we've been doing until now.
      Implements the second big part of proposal 220; Closes
      ticket 15055.
    - Clients now support including Ed25519 identity keys in the EXTEND2
      cells they generate. By default, this is controlled by a consensus
      parameter, currently disabled. You can turn this feature on for
      testing by setting ExtendByEd25519ID in your configuration. This
      might make your traffic appear different than the traffic
      generated by other users, however. Implements part of ticket
      15056; part of proposal 220.
    - Relays now understand requests to extend to other relays by their
      Ed25519 identity keys. When an Ed25519 identity key is included in
      an EXTEND2 cell, the relay will only extend the circuit if the
      other relay can prove ownership of that identity. Implements part
      of ticket 15056; part of proposal 220.

  o Major bugfixes (scheduler):
    - Actually compare circuit policies in ewma_cmp_cmux(). This bug
      caused the channel scheduler to behave more or less randomly,
      rather than preferring channels with higher-priority circuits.
      Fixes bug 20459; bugfix on 0.2.6.2-alpha.

  o Minor features (controller):
    - When HSFETCH arguments cannot be parsed, say "Invalid argument"
      rather than "unrecognized." Closes ticket 20389; patch from
      Ivan Markin.

  o Minor features (diagnostic, directory client):
    - Warn when we find an unexpected inconsistency in directory
      download status objects. Prevents some negative consequences of
      bug 20593.

  o Minor features (directory authority):
    - Add a new authority-only AuthDirTestEd25519LinkKeys option (on by
      default) to control whether authorities should try to probe relays
      by their Ed25519 link keys. This option will go away in a few
      releases--unless we encounter major trouble in our ed25519 link
      protocol rollout, in which case it will serve as a safety option.

  o Minor features (directory cache):
    - Relays and bridges will now refuse to serve the consensus they
      have if they know it is too old for a client to use. Closes
      ticket 20511.

  o Minor features (ed25519 link handshake):
    - Advertise support for the ed25519 link handshake using the
      subprotocol-versions mechanism, so that clients can tell which
      relays can identity themselves by Ed25519 ID. Closes ticket 20552.

  o Minor features (fingerprinting resistence, authentication):
    - Extend the length of RSA keys used for TLS link authentication to
      2048 bits. (These weren't used for forward secrecy; for forward
      secrecy, we used P256.) Closes ticket 13752.

  o Minor features (infrastructure):
    - Implement smartlist_add_strdup() function. Replaces the use of
      smartlist_add(sl, tor_strdup(str)). Closes ticket 20048.

  o Minor bugfixes (client):
    - When clients that use bridges start up with a cached consensus on
      disk, they were ignoring it and downloading a new one. Now they
      use the cached one. Fixes bug 20269; bugfix on 0.2.3.12-alpha.

  o Minor bugfixes (configuration):
    - Accept non-space whitespace characters after the severity level in
      the `Log` option. Fixes bug 19965; bugfix on 0.2.1.1-alpha.
    - Support "TByte" and "TBytes" units in options given in bytes.
      "TB", "terabyte(s)", "TBit(s)" and "terabit(s)" were already
      supported. Fixes bug 20622; bugfix on 0.2.0.14-alpha.

  o Minor bugfixes (consensus weight):
    - Add new consensus method that initializes bw weights to 1 instead
      of 0. This prevents a zero weight from making it all the way to
      the end (happens in small testing networks) and causing an error.
      Fixes bug 14881; bugfix on 0.2.2.17-alpha.

  o Minor bugfixes (descriptors):
    - Correctly recognise downloaded full descriptors as valid, even
      when using microdescriptors as circuits. This affects clients with
      FetchUselessDescriptors set, and may affect directory authorities.
      Fixes bug 20839; bugfix on 0.2.3.2-alpha.

  o Minor bugfixes (directory system):
    - Download all consensus flavors, descriptors, and authority
      certificates when FetchUselessDescriptors is set, regardless of
      whether tor is a directory cache or not. Fixes bug 20667; bugfix
      on all recent tor versions.
    - Bridges and relays now use microdescriptors (like clients do)
      rather than old-style router descriptors. Now bridges will blend
      in with clients in terms of the circuits they build. Fixes bug
      6769; bugfix on 0.2.3.2-alpha.

  o Minor bugfixes (ed25519 certificates):
    - Correctly interpret ed25519 certificates that would expire some
      time after 19 Jan 2038. Fixes bug 20027; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (hidden services):
    - Stop ignoring misconfigured hidden services. Instead, refuse to
      start tor until the misconfigurations have been corrected. Fixes
      bug 20559; bugfix on multiple commits in 0.2.7.1-alpha
      and earlier.

  o Minor bugfixes (memory leak at exit):
    - Fix a small harmless memory leak at exit of the previously unused
      RSA->Ed identity cross-certificate. Fixes bug 17779; bugfix
      on 0.2.7.2-alpha.

  o Minor bugfixes (util):
    - When finishing writing a file to disk, if we were about to replace
      the file with the temporary file created before and we fail to
      replace it, remove the temporary file so it doesn't stay on disk.
      Fixes bug 20646; bugfix on tor-0.2.0.7-alpha. Patch by fk.

  o Minor bugfixes (Windows):
    - Check for getpagesize before using it to mmap files. This fixes
      compilation in some MinGW environments. Fixes bug 20530; bugfix on
      0.1.2.1-alpha. Reported by "ice".

  o Code simplification and refactoring:
    - Abolish all global guard context in entrynodes.c; replace with new
      guard_selection_t structure as preparation for proposal 271.
      Closes ticket 19858.
    - Introduce rend_service_is_ephemeral() that tells if given onion
      service is ephemeral. Replace unclear NULL-checkings for service
      directory with this function. Closes ticket 20526.
    - Extract magic numbers in circuituse.c into defined variables.
    - Refactor circuit_is_available_for_use to remove unnecessary check.
    - Refactor circuit_predict_and_launch_new for readability and
      testability. Closes ticket 18873.
    - Refactor large if statement in purpose_needs_anonymity to use
      switch statement instead. Closes part of ticket 20077.
    - Refactor the hashing API to return negative values for errors, as
      is done as throughout the codebase. Closes ticket 20717.
    - Remove data structures that were used to index or_connection
      objects by their RSA identity digests. These structures are fully
      redundant with the similar structures used in the
      channel abstraction.
    - Remove duplicate code in the channel_write_*cell() functions.
      Closes ticket 13827; patch from Pingl.
    - Remove redundant behavior of is_sensitive_dir_purpose, refactor to
      use only purpose_needs_anonymity. Closes part of ticket 20077.
    - The code to generate and parse EXTEND and EXTEND2 cells has been
      replaced with code automatically generated by the
      "trunnel" utility.

  o Documentation:
    - Include the "TBits" unit in Tor's man page. Fixes part of bug
      20622; bugfix on tor-0.2.5.1-alpha.
    - Change '1' to 'weight_scale' in consensus bw weights calculation
      comments, as that is reality. Closes ticket 20273. Patch
      from pastly.
    - Correct the value for AuthDirGuardBWGuarantee in the manpage, from
      250 KBytes to 2 MBytes. Fixes bug 20435; bugfix
      on tor-0.2.5.6-alpha.
    - Stop the man page from incorrectly stating that HiddenServiceDir
      must already exist. Fixes 20486.
    - Clarify that when ClientRejectInternalAddresses is enabled (which
      is the default), multicast DNS hostnames for machines on the local
      network (of the form *.local) are also rejected. Closes
      ticket 17070.

  o Removed features:
    - The AuthDirMaxServersPerAuthAddr option no longer exists: The same
      limit for relays running on a single IP applies to authority IP
      addresses as well as to non-authority IP addresses. Closes
      ticket 20960.
    - The UseDirectoryGuards torrc option no longer exists: all users
      that use entry guards will also use directory guards. Related to
      proposal 271; implements part of ticket 20831.

  o Testing:
    - New unit tests for tor_htonll(). Closes ticket 19563. Patch
      from "overcaffeinated".
    - Perform the coding style checks when running the tests and fail
      when coding style violations are found. Closes ticket 5500.
    - Add tests for networkstatus_compute_bw_weights_v10.
    - Add unit tests circuit_predict_and_launch_new.
    - Extract dummy_origin_circuit_new so it can be used by other
      test functions.


Changes in version 0.2.8.12 - 2016-12-19
  Tor 0.2.8.12 backports a fix for a medium-severity issue (bug 21018
  below) where Tor clients could crash when attempting to visit a
  hostile hidden service. Clients are recommended to upgrade as packages
  become available for their systems.

  It also includes an updated list of fallback directories, backported
  from 0.2.9.

  Now that the Tor 0.2.9 series is stable, only major bugfixes will be
  backported to 0.2.8 in the future.

  o Major bugfixes (parsing, security, backported from 0.2.9.8):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Minor features (fallback directory list, backported from 0.2.9.8):
    - Replace the 81 remaining fallbacks of the 100 originally
      introduced in Tor 0.2.8.3-alpha in March 2016, with a list of 177
      fallbacks (123 new, 54 existing, 27 removed) generated in December
      2016. Resolves ticket 20170.

  o Minor features (geoip, backported from 0.2.9.7-rc):
    - Update geoip and geoip6 to the December 7 2016 Maxmind GeoLite2
      Country database.


Changes in version 0.2.9.8 - 2016-12-19
  Tor 0.2.9.8 is the first stable release of the Tor 0.2.9 series.

  The Tor 0.2.9 series makes mandatory a number of security features
  that were formerly optional. It includes support for a new shared-
  randomness protocol that will form the basis for next generation
  hidden services, includes a single-hop hidden service mode for
  optimizing .onion services that don't actually want to be hidden,
  tries harder not to overload the directory authorities with excessive
  downloads, and supports a better protocol versioning scheme for
  improved compatibility with other implementations of the Tor protocol.

  And of course, there are numerous other bugfixes and improvements.

  This release also includes a fix for a medium-severity issue (bug
  21018 below) where Tor clients could crash when attempting to visit a
  hostile hidden service. Clients are recommended to upgrade as packages
  become available for their systems.

  Below are the changes since 0.2.9.7-rc. For a list of all changes
  since 0.2.8, see the ReleaseNotes file.

  o Major bugfixes (parsing, security):
    - Fix a bug in parsing that could cause clients to read a single
      byte past the end of an allocated region. This bug could be used
      to cause hardened clients (built with --enable-expensive-hardening)
      to crash if they tried to visit a hostile hidden service. Non-
      hardened clients are only affected depending on the details of
      their platform's memory allocator. Fixes bug 21018; bugfix on
      0.2.0.8-alpha. Found by using libFuzzer. Also tracked as TROVE-
      2016-12-002 and as CVE-2016-1254.

  o Minor features (fallback directory list):
    - Replace the 81 remaining fallbacks of the 100 originally
      introduced in Tor 0.2.8.3-alpha in March 2016, with a list of 177
      fallbacks (123 new, 54 existing, 27 removed) generated in December
      2016. Resolves ticket 20170.


Changes in version 0.2.9.7-rc - 2016-12-12
  Tor 0.2.9.7-rc fixes a few small bugs remaining in Tor 0.2.9.6-rc,
  including a few that had prevented tests from passing on
  some platforms.

  o Minor features (geoip):
    - Update geoip and geoip6 to the December 7 2016 Maxmind GeoLite2
      Country database.

  o Minor bugfix (build):
    - The current Git revision when building from a local repository is
      now detected correctly when using git worktrees. Fixes bug 20492;
      bugfix on 0.2.3.9-alpha.

  o Minor bugfixes (directory authority):
    - When computing old Tor protocol line version in protover, we were
      looking at 0.2.7.5 twice instead of a specific case for
      0.2.9.1-alpha. Fixes bug 20810; bugfix on 0.2.9.4-alpha.

  o Minor bugfixes (download scheduling):
    - Resolve a "bug" warning when considering a download schedule whose
      delay had approached INT_MAX. Fixes 20875; bugfix on 0.2.9.5-alpha.

  o Minor bugfixes (logging):
    - Downgrade a harmless log message about the
      pending_entry_connections list from "warn" to "info". Mitigates
      bug 19926.

  o Minor bugfixes (memory leak):
    - Fix a small memory leak when receiving AF_UNIX connections on a
      SocksPort. Fixes bug 20716; bugfix on 0.2.6.3-alpha.
    - When moving a signed descriptor object from a source to an
      existing destination, free the allocated memory inside that
      destination object. Fixes bug 20715; bugfix on 0.2.8.3-alpha.

  o Minor bugfixes (memory leak, use-after-free, linux seccomp2 sandbox):
    - Fix a memory leak and use-after-free error when removing entries
      from the sandbox's getaddrinfo() cache. Fixes bug 20710; bugfix on
      0.2.5.5-alpha. Patch from "cypherpunks".

  o Minor bugfixes (portability):
    - Use the correct spelling of MAC_OS_X_VERSION_10_12 on configure.ac
      Fixes bug 20935; bugfix on 0.2.9.6-rc.

  o Minor bugfixes (unit tests):
    - Stop expecting NetBSD unit tests to report success for ipfw. Part
      of a fix for bug 19960; bugfix on 0.2.9.5-alpha.
    - Fix tolerances in unit tests for monotonic time comparisons
      between nanoseconds and microseconds. Previously, we accepted a 10
      us difference only, which is not realistic on every platform's
      clock_gettime(). Fixes bug 19974; bugfix on 0.2.9.1-alpha.
    - Remove a double-free in the single onion service unit test. Stop
      ignoring a return value. Make future changes less error-prone.
      Fixes bug 20864; bugfix on 0.2.9.6-rc.


Changes in version 0.2.8.11 - 2016-12-08
  Tor 0.2.8.11 backports fixes for additional portability issues that
  could prevent Tor from building correctly on OSX Sierra, or with
  OpenSSL 1.1. Affected users should upgrade; others can safely stay
  with 0.2.8.10.

  o Minor bugfixes (portability):
    - Avoid compilation errors when building on OSX Sierra. Sierra began
      to support the getentropy() and clock_gettime() APIs, but created
      a few problems in doing so. Tor 0.2.9 has a more thorough set of
      workarounds; in 0.2.8, we are just using the /dev/urandom and mach
      monotonic time interfaces. Fixes bug 20865. Bugfix
      on 0.2.8.1-alpha.

  o Minor bugfixes (portability, backport from 0.2.9.5-alpha):
    - Fix compilation with OpenSSL 1.1 and less commonly-used CPU
      architectures. Closes ticket 20588.


Changes in version 0.2.8.10 - 2016-12-02
  Tor 0.2.8.10 backports a fix for a bug that would sometimes make clients
  unusable after they left standby mode. It also backports fixes for
  a few portability issues and a small but problematic memory leak.

  o Major bugfixes (client reliability, backport from 0.2.9.5-alpha):
    - When Tor leaves standby because of a new application request, open
      circuits as needed to serve that request. Previously, we would
      potentially wait a very long time. Fixes part of bug 19969; bugfix
      on 0.2.8.1-alpha.

  o Major bugfixes (client performance, backport from 0.2.9.5-alpha):
    - Clients now respond to new application stream requests immediately
      when they arrive, rather than waiting up to one second before
      starting to handle them. Fixes part of bug 19969; bugfix
      on 0.2.8.1-alpha.

  o Minor bugfixes (portability, backport from 0.2.9.6-rc):
    - Work around a bug in the OSX 10.12 SDK that would prevent us from
      successfully targeting earlier versions of OSX. Resolves
      ticket 20235.

  o Minor bugfixes (portability, backport from 0.2.9.5-alpha):
    - Fix implicit conversion warnings under OpenSSL 1.1. Fixes bug
      20551; bugfix on 0.2.1.1-alpha.

  o Minor bugfixes (relay, backport from 0.2.9.5-alpha):
    - Work around a memory leak in OpenSSL 1.1 when encoding public
      keys. Fixes bug 20553; bugfix on 0.0.2pre8.

  o Minor features (geoip):
    - Update geoip and geoip6 to the November 3 2016 Maxmind GeoLite2
      Country database.

Changes in version 0.2.9.6-rc - 2016-12-02
  Tor 0.2.9.6-rc fixes a few remaining bugs found in the previous alpha
  version. We hope that it will be ready to become stable soon, and we
  encourage everyone to test this release. If no showstopper bugs are
  found here, the next 0.2.9 release will be stable.

  o Major bugfixes (relay, resolver, logging):
    - For relays that don't know their own address, avoid attempting a
      local hostname resolve for each descriptor we download. This
      will cut down on the number of "Success: chose address 'x.x.x.x'"
      log lines, and also avoid confusing clock jumps if the resolver
      is slow. Fixes bugs 20423 and 20610; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (client, fascistfirewall):
    - Avoid spurious warnings when ReachableAddresses or FascistFirewall
      is set. Fixes bug 20306; bugfix on 0.2.8.2-alpha.

  o Minor bugfixes (hidden services):
    - Stop ignoring the anonymity status of saved keys for hidden
      services and single onion services when first starting tor.
      Instead, refuse to start tor if any hidden service key has been
      used in a different hidden service anonymity mode. Fixes bug
      20638; bugfix on 17178 in 0.2.9.3-alpha; reported by ahf.

  o Minor bugfixes (portability):
    - Work around a bug in the OSX 10.12 SDK that would prevent us from
      successfully targeting earlier versions of OSX. Resolves
      ticket 20235.
    - Run correctly when built on Windows build environments that
      require _vcsprintf(). Fixes bug 20560; bugfix on 0.2.2.11-alpha.

  o Minor bugfixes (single onion services, Tor2web):
    - Stop complaining about long-term one-hop circuits deliberately
      created by single onion services and Tor2web. These log messages
      are intended to diagnose issue 8387, which relates to circuits
      hanging around forever for no reason. Fixes bug 20613; bugfix on
      0.2.9.1-alpha. Reported by "pastly".

  o Minor bugfixes (unit tests):
    - Stop spurious failures in the local interface address discovery
      unit tests. Fixes bug 20634; bugfix on 0.2.8.1-alpha; patch by
      Neel Chauhan.

  o Documentation:
    - Correct the minimum bandwidth value in torrc.sample, and queue a
      corresponding change for torrc.minimal. Closes ticket 20085.


Changes in version 0.2.9.5-alpha - 2016-11-08
  Tor 0.2.9.5-alpha fixes numerous bugs discovered in the previous alpha
  version. We believe one or two probably remain, and we encourage
  everyone to test this release.

  o Major bugfixes (client performance):
    - Clients now respond to new application stream requests immediately
      when they arrive, rather than waiting up to one second before
      starting to handle them. Fixes part of bug 19969; bugfix
      on 0.2.8.1-alpha.

  o Major bugfixes (client reliability):
    - When Tor leaves standby because of a new application request, open
      circuits as needed to serve that request. Previously, we would
      potentially wait a very long time. Fixes part of bug 19969; bugfix
      on 0.2.8.1-alpha.

  o Major bugfixes (download scheduling):
    - When using an exponential backoff schedule, do not give up on
      downloading just because we have failed a bunch of times. Since
      each delay is longer than the last, retrying indefinitely won't
      hurt. Fixes bug 20536; bugfix on 0.2.9.1-alpha.
    - If a consensus expires while we are waiting for certificates to
      download, stop waiting for certificates.
    - If we stop waiting for certificates less than a minute after we
      started downloading them, do not consider the certificate download
      failure a separate failure. Fixes bug 20533; bugfix
      on 0.2.0.9-alpha.
    - Remove the maximum delay on exponential-backoff scheduling. Since
      we now allow an infinite number of failures (see ticket 20536), we
      must now allow the time to grow longer on each failure. Fixes part
      of bug 20534; bugfix on 0.2.9.1-alpha.
    - Make our initial download delays closer to those from 0.2.8. Fixes
      another part of bug 20534; bugfix on 0.2.9.1-alpha.
    - When determining when to download a directory object, handle times
      after 2038 if the operating system supports them. (Someday this
      will be important!) Fixes bug 20587; bugfix on 0.2.8.1-alpha.
    - When using exponential backoff in test networks, use a lower
      exponent, so the delays do not vary as much. This helps test
      networks bootstrap consistently. Fixes bug 20597; bugfix on 20499.

  o Minor features (geoip):
    - Update geoip and geoip6 to the November 3 2016 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (client directory scheduling):
    - Treat "relay too busy to answer request" as a failed request and a
      reason to back off on our retry frequency. This is safe now that
      exponential backoffs retry indefinitely, and avoids a bug where we
      would reset our download schedule erroneously. Fixes bug 20593;
      bugfix on 0.2.9.1-alpha.

  o Minor bugfixes (client, logging):
    - Remove a BUG warning in circuit_pick_extend_handshake(). Instead,
      assume all nodes support EXTEND2. Use ntor whenever a key is
      available. Fixes bug 20472; bugfix on 0.2.9.3-alpha.
    - On DNSPort, stop logging a BUG warning on a failed hostname
      lookup. Fixes bug 19869; bugfix on 0.2.9.1-alpha.

  o Minor bugfixes (hidden services):
    - When configuring hidden services, check every hidden service
      directory's permissions. Previously, we only checked the last
      hidden service. Fixes bug 20529; bugfix the work to fix 13942
      in 0.2.6.2-alpha.

  o Minor bugfixes (portability):
    - Fix compilation with OpenSSL 1.1 and less commonly-used CPU
      architectures. Closes ticket 20588.
    - Use ECDHE ciphers instead of ECDH in tortls tests. LibreSSL has
      removed the ECDH ciphers which caused the tests to fail on
      platforms which use it. Fixes bug 20460; bugfix on 0.2.8.1-alpha.
    - Fix implicit conversion warnings under OpenSSL 1.1. Fixes bug
      20551; bugfix on 0.2.1.1-alpha.

  o Minor bugfixes (relay bootstrap):
    - Ensure relays don't make multiple connections during bootstrap.
      Fixes bug 20591; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (relay):
    - Work around a memory leak in OpenSSL 1.1 when encoding public
      keys. Fixes bug 20553; bugfix on 0.0.2pre8.
    - Avoid a small memory leak when informing worker threads about
      rotated onion keys. Fixes bug 20401; bugfix on 0.2.6.3-alpha.
    - Do not try to parallelize workers more than 16x without the user
      explicitly configuring us to do so, even if we do detect more than
      16 CPU cores. Fixes bug 19968; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (single onion services):
    - Start correctly when creating a single onion service in a
      directory that did not previously exist. Fixes bug 20484; bugfix
      on 0.2.9.3-alpha.

  o Minor bugfixes (testing):
    - Avoid a unit test failure on systems with over 16 detectable CPU
      cores. Fixes bug 19968; bugfix on 0.2.3.1-alpha.

  o Documentation:
    - Clarify that setting HiddenServiceNonAnonymousMode requires you to
      also set "SOCKSPort 0". Fixes bug 20487; bugfix on 0.2.9.3-alpha.
    - Module-level documentation for several more modules. Closes
      tickets 19287 and 19290.


Changes in version 0.2.8.9 - 2016-10-17
  Tor 0.2.8.9 backports a fix for a security hole in previous versions
  of Tor that would allow a remote attacker to crash a Tor client,
  hidden service, relay, or authority. All Tor users should upgrade to
  this version, or to 0.2.9.4-alpha. Patches will be released for older
  versions of Tor.

  o Major features (security fixes, also in 0.2.9.4-alpha):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Minor features (geoip):
    - Update geoip and geoip6 to the October 4 2016 Maxmind GeoLite2
      Country database.


Changes in version 0.2.9.4-alpha - 2016-10-17
  Tor 0.2.9.4-alpha fixes a security hole in previous versions of Tor
  that would allow a remote attacker to crash a Tor client, hidden
  service, relay, or authority. All Tor users should upgrade to this
  version, or to 0.2.8.9. Patches will be released for older versions
  of Tor.

  Tor 0.2.9.4-alpha also adds numerous small features and fix-ups to
  previous versions of Tor, including the implementation of a feature to
  future- proof the Tor ecosystem against protocol changes, some bug
  fixes necessary for Tor Browser to use unix domain sockets correctly,
  and several portability improvements. We anticipate that this will be
  the last alpha in the Tor 0.2.9 series, and that the next release will
  be a release candidate.

  o Major features (security fixes):
    - Prevent a class of security bugs caused by treating the contents
      of a buffer chunk as if they were a NUL-terminated string. At
      least one such bug seems to be present in all currently used
      versions of Tor, and would allow an attacker to remotely crash
      most Tor instances, especially those compiled with extra compiler
      hardening. With this defense in place, such bugs can't crash Tor,
      though we should still fix them as they occur. Closes ticket
      20384 (TROVE-2016-10-001).

  o Major features (subprotocol versions):
    - Tor directory authorities now vote on a set of recommended
      subprotocol versions, and on a set of required subprotocol
      versions. Clients and relays that lack support for a _required_
      subprotocol version will not start; those that lack support for a
      _recommended_ subprotocol version will warn the user to upgrade.
      Closes ticket 19958; implements part of proposal 264.
    - Tor now uses "subprotocol versions" to indicate compatibility.
      Previously, versions of Tor looked at the declared Tor version of
      a relay to tell whether they could use a given feature. Now, they
      should be able to rely on its declared subprotocol versions. This
      change allows compatible implementations of the Tor protocol(s) to
      exist without pretending to be 100% bug-compatible with particular
      releases of Tor itself. Closes ticket 19958; implements part of
      proposal 264.

  o Minor feature (fallback directories):
    - Remove broken fallbacks from the hard-coded fallback directory
      list. Closes ticket 20190; patch by teor.

  o Minor features (client, directory):
    - Since authorities now omit all routers that lack the Running and
      Valid flags, we assume that any relay listed in the consensus must
      have those flags. Closes ticket 20001; implements part of
      proposal 272.

  o Minor features (compilation, portability):
    - Compile correctly on MacOS 10.12 (aka "Sierra"). Closes
      ticket 20241.

  o Minor features (development tools, etags):
    - Teach the "make tags" Makefile target how to correctly find
      "MOCK_IMPL" function definitions. Patch from nherring; closes
      ticket 16869.

  o Minor features (geoip):
    - Update geoip and geoip6 to the October 4 2016 Maxmind GeoLite2
      Country database.

  o Minor features (unix domain sockets):
    - When configuring a unix domain socket for a SocksPort,
      ControlPort, or Hidden service, you can now wrap the address in
      quotes, using C-style escapes inside the quotes. This allows unix
      domain socket paths to contain spaces.

  o Minor features (virtual addresses):
    - Increase the maximum number of bits for the IPv6 virtual network
      prefix from 16 to 104. In this way, the condition for address
      allocation is less restrictive. Closes ticket 20151; feature
      on 0.2.4.7-alpha.

  o Minor bugfixes (address discovery):
    - Stop reordering IP addresses returned by the OS. This makes it
      more likely that Tor will guess the same relay IP address every
      time. Fixes issue 20163; bugfix on 0.2.7.1-alpha, ticket 17027.
      Reported by René Mayrhofer, patch by "cypherpunks".

  o Minor bugfixes (client, unix domain sockets):
    - Disable IsolateClientAddr when using AF_UNIX backed SocksPorts as
      the client address is meaningless. Fixes bug 20261; bugfix
      on 0.2.6.3-alpha.

  o Minor bugfixes (compilation, OpenBSD):
    - Detect Libevent2 functions correctly on systems that provide
      libevent2, but where libevent1 is linked with -levent. Fixes bug
      19904; bugfix on 0.2.2.24-alpha. Patch from Rubiate.

  o Minor bugfixes (configuration):
    - When parsing quoted configuration values from the torrc file,
      handle windows line endings correctly. Fixes bug 19167; bugfix on
      0.2.0.16-alpha. Patch from "Pingl".

  o Minor bugfixes (getpass):
    - Defensively fix a non-triggerable heap corruption at do_getpass()
      to protect ourselves from mistakes in the future. Fixes bug
      19223; bugfix on 0.2.7.3-rc. Bug found by Guido Vranken, patch
      by nherring.

  o Minor bugfixes (hidden service):
    - Allow hidden services to run on IPv6 addresses even when the
      IPv6Exit option is not set. Fixes bug 18357; bugfix
      on 0.2.4.7-alpha.

  o Documentation:
    - Add module-level internal documentation for 36 C files that
      previously didn't have a high-level overview. Closes ticket #20385.

  o Required libraries:
    - When building with OpenSSL, Tor now requires version 1.0.1 or
      later. OpenSSL 1.0.0 and earlier are no longer supported by the
      OpenSSL team, and should not be used. Closes ticket 20303.


Changes in version 0.2.9.3-alpha - 2016-09-23
  Tor 0.2.9.3-alpha adds improved support for entities that want to make
  high-performance services available through the Tor .onion mechanism
  without themselves receiving anonymity as they host those services. It
  also tries harder to ensure that all steps on a circuit are using the
  strongest crypto possible, strengthens some TLS properties, and
  resolves several bugs -- including a pair of crash bugs from the 0.2.8
  series. Anybody running an earlier version of 0.2.9.x should upgrade.

  o Major bugfixes (crash, also in 0.2.8.8):
    - Fix a complicated crash bug that could affect Tor clients
      configured to use bridges when replacing a networkstatus consensus
      in which one of their bridges was mentioned. OpenBSD users saw
      more crashes here, but all platforms were potentially affected.
      Fixes bug 20103; bugfix on 0.2.8.2-alpha.

  o Major bugfixes (relay, OOM handler, also in 0.2.8.8):
    - Fix a timing-dependent assertion failure that could occur when we
      tried to flush from a circuit after having freed its cells because
      of an out-of-memory condition. Fixes bug 20203; bugfix on
      0.2.8.1-alpha. Thanks to "cypherpunks" for help diagnosing
      this one.

  o Major features (circuit building, security):
    - Authorities, relays and clients now require ntor keys in all
      descriptors, for all hops (except for rare hidden service protocol
      cases), for all circuits, and for all other roles. Part of
      ticket 19163.
    - Tor authorities, relays, and clients only use ntor, except for
      rare cases in the hidden service protocol. Part of ticket 19163.

  o Major features (single-hop "hidden" services):
    - Add experimental HiddenServiceSingleHopMode and
      HiddenServiceNonAnonymousMode options. When both are set to 1,
      every hidden service on a Tor instance becomes a non-anonymous
      Single Onion Service. Single Onions make one-hop (direct)
      connections to their introduction and renzedvous points. One-hop
      circuits make Single Onion servers easily locatable, but clients
      remain location-anonymous. This is compatible with the existing
      hidden service implementation, and works on the current tor
      network without any changes to older relays or clients. Implements
      proposal 260, completes ticket 17178. Patch by teor and asn.

  o Major features (resource management):
    - Tor can now notice it is about to run out of sockets, and
      preemptively close connections of lower priority. (This feature is
      off by default for now, since the current prioritizing method is
      yet not mature enough. You can enable it by setting
      "DisableOOSCheck 0", but watch out: it might close some sockets
      you would rather have it keep.) Closes ticket 18640.

  o Major bugfixes (circuit building):
    - Hidden service client-to-intro-point and service-to-rendezvous-
      point circuits use the TAP key supplied by the protocol, to avoid
      epistemic attacks. Fixes bug 19163; bugfix on 0.2.4.18-rc.

  o Major bugfixes (compilation, OpenBSD):
    - Fix a Libevent-detection bug in our autoconf script that would
      prevent Tor from linking successfully on OpenBSD. Patch from
      rubiate. Fixes bug 19902; bugfix on 0.2.9.1-alpha.

  o Major bugfixes (hidden services):
    - Clients now require hidden services to include the TAP keys for
      their intro points in the hidden service descriptor. This prevents
      an inadvertent upgrade to ntor, which a malicious hidden service
      could use to distinguish clients by consensus version. Fixes bug
      20012; bugfix on 0.2.4.8-alpha. Patch by teor.

  o Minor features (security, TLS):
    - Servers no longer support clients that without AES ciphersuites.
      (3DES is no longer considered an acceptable cipher.) We believe
      that no such Tor clients currently exist, since Tor has required
      OpenSSL 0.9.7 or later since 2009. Closes ticket 19998.

  o Minor feature (fallback directories):
    - Remove 8 fallbacks that are no longer suitable, leaving 81 of the
      100 fallbacks originally introduced in Tor 0.2.8.2-alpha in March
      2016. Closes ticket 20190; patch by teor.

  o Minor features (geoip, also in 0.2.8.8):
    - Update geoip and geoip6 to the September 6 2016 Maxmind GeoLite2
      Country database.

  o Minor feature (port flags):
    - Add new flags to the *Port options to finer control over which
      requests are allowed. The flags are NoDNSRequest, NoOnionTraffic,
      and the synthetic flag OnionTrafficOnly, which is equivalent to
      NoDNSRequest, NoIPv4Traffic, and NoIPv6Traffic. Closes enhancement
      18693; patch by "teor".

  o Minor features (directory authority):
    - After voting, if the authorities decide that a relay is not
      "Valid", they no longer include it in the consensus at all. Closes
      ticket 20002; implements part of proposal 272.

  o Minor features (testing):
    - Disable memory protections on OpenBSD when performing our unit
      tests for memwipe(). The test deliberately invokes undefined
      behavior, and the OpenBSD protections interfere with this. Patch
      from "rubiate". Closes ticket 20066.

  o Minor features (testing, ipv6):
    - Add the single-onion and single-onion-ipv6 chutney targets to
      "make test-network-all". This requires a recent chutney version
      with the single onion network flavours (git c72a652 or later).
      Closes ticket 20072; patch by teor.
    - Add the hs-ipv6 chutney target to make test-network-all's IPv6
      tests. Remove bridges+hs, as it's somewhat redundant. This
      requires a recent chutney version that supports IPv6 clients,
      relays, and authorities. Closes ticket 20069; patch by teor.

  o Minor features (Tor2web):
    - Make Tor2web clients respect ReachableAddresses. This feature was
      inadvertently enabled in 0.2.8.6, then removed by bugfix 19973 on
      0.2.8.7. Implements feature 20034. Patch by teor.

  o Minor features (unit tests):
    - We've done significant work to make the unit tests run faster.
    - Our link-handshake unit tests now check that when invalid
      handshakes fail, they fail with the error messages we expected.
    - Our unit testing code that captures log messages no longer
      prevents them from being written out if the user asked for them
      (by passing --debug or --info or or --notice --warn to the "test"
      binary). This change prevents us from missing unexpected log
      messages simply because we were looking for others. Related to
      ticket 19999.
    - The unit tests now log all warning messages with the "BUG" flag.
      Previously, they only logged errors by default. This change will
      help us make our testing code more correct, and make sure that we
      only hit this code when we mean to. In the meantime, however,
      there will be more warnings in the unit test logs than before.
      This is preparatory work for ticket 19999.
    - The unit tests now treat any failure of a "tor_assert_nonfatal()"
      assertion as a test failure.

  o Minor bug fixes (circuits):
    - Use the CircuitBuildTimeout option whenever
      LearnCircuitBuildTimeout is disabled. Previously, we would respect
      the option when a user disabled it, but not when it was disabled
      because some other option was set. Fixes bug 20073; bugfix on
      0.2.4.12-alpha. Patch by teor.

  o Minor bugfixes (allocation):
    - Change how we allocate memory for large chunks on buffers, to
      avoid a (currently impossible) integer overflow, and to waste less
      space when allocating unusually large chunks. Fixes bug 20081;
      bugfix on 0.2.0.16-alpha. Issue identified by Guido Vranken.
    - Always include orconfig.h before including any other C headers.
      Sometimes, it includes macros that affect the behavior of the
      standard headers. Fixes bug 19767; bugfix on 0.2.9.1-alpha (the
      first version to use AC_USE_SYSTEM_EXTENSIONS).
    - Fix a syntax error in the IF_BUG_ONCE__() macro in non-GCC-
      compatible compilers. Fixes bug 20141; bugfix on 0.2.9.1-alpha.
      Patch from Gisle Vanem.
    - Stop trying to build with Clang 4.0's -Wthread-safety warnings.
      They apparently require a set of annotations that we aren't
      currently using, and they create false positives in our pthreads
      wrappers. Fixes bug 20110; bugfix on 0.2.9.1-alpha.

  o Minor bugfixes (directory authority):
    - Die with a more useful error when the operator forgets to place
      the authority_signing_key file into the keys directory. This
      avoids an uninformative assert & traceback about having an invalid
      key. Fixes bug 20065; bugfix on 0.2.0.1-alpha.
    - When allowing private addresses, mark Exits that only exit to
      private locations as such. Fixes bug 20064; bugfix
      on 0.2.2.9-alpha.

  o Minor bugfixes (documentation):
    - Document the default PathsNeededToBuildCircuits value that's used
      by clients when the directory authorities don't set
      min_paths_for_circs_pct. Fixes bug 20117; bugfix on 02c320916e02
      in 0.2.4.10-alpha. Patch by teor, reported by Jesse V.
    - Fix manual for the User option: it takes a username, not a UID.
      Fixes bug 19122; bugfix on 0.0.2pre16 (the first version to have
      a manpage!).

  o Minor bugfixes (hidden services):
    - Stop logging intro point details to the client log on certain
      error conditions. Fixed as part of bug 20012; bugfix on
      0.2.4.8-alpha. Patch by teor.

  o Minor bugfixes (IPv6, testing):
    - Check for IPv6 correctly on Linux when running test networks.
      Fixes bug 19905; bugfix on 0.2.7.3-rc; patch by teor.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Add permission to run the sched_yield() and sigaltstack() system
      calls, in order to support versions of Tor compiled with asan or
      ubsan code that use these calls. Now "sandbox 1" and
      "--enable-expensive-hardening" should be compatible on more
      systems. Fixes bug 20063; bugfix on 0.2.5.1-alpha.

  o Minor bugfixes (logging):
    - When logging a message from the BUG() macro, be explicit about
      what we were asserting. Previously we were confusing what we were
      asserting with what the bug was. Fixes bug 20093; bugfix
      on 0.2.9.1-alpha.
    - When we are unable to remove the bw_accounting file, do not warn
      if the reason we couldn't remove it was that it didn't exist.
      Fixes bug 19964; bugfix on 0.2.5.4-alpha. Patch from 'pastly'.

  o Minor bugfixes (option parsing):
    - Count unix sockets when counting client listeners (SOCKS, Trans,
      NATD, and DNS). This has no user-visible behaviour changes: these
      options are set once, and never read. Required for correct
      behaviour in ticket 17178. Fixes bug 19677; bugfix on
      0.2.6.3-alpha. Patch by teor.

  o Minor bugfixes (options):
    - Check the consistency of UseEntryGuards and EntryNodes more
      reliably. Fixes bug 20074; bugfix on 0.2.4.12-alpha. Patch
      by teor.
    - Stop changing the configured value of UseEntryGuards on
      authorities and Tor2web clients. Fixes bug 20074; bugfix on
      commits 51fc6799 in 0.1.1.16-rc and acda1735 in 0.2.4.3-alpha.
      Patch by teor.

  o Minor bugfixes (Tor2web):
    - Prevent Tor2web clients running hidden services, these services
      are not anonymous due to the one-hop client paths. Fixes bug
      19678. Patch by teor.

  o Minor bugfixes (unit tests):
    - Fix a shared-random unit test that was failing on big endian
      architectures due to internal representation of a integer copied
      to a buffer. The test is changed to take a full 32 bytes of data
      and use the output of a python script that make the COMMIT and
      REVEAL calculation according to the spec. Fixes bug 19977; bugfix
      on 0.2.9.1-alpha.
    - The tor_tls_server_info_callback unit test no longer crashes when
      debug-level logging is turned on. Fixes bug 20041; bugfix
      on 0.2.8.1-alpha.


Changes in version 0.2.8.8 - 2016-09-23
  Tor 0.2.8.8 fixes two crash bugs present in previous versions of the
  0.2.8.x series. Relays running 0.2.8.x should upgrade, as should users
  who select public relays as their bridges.

  o Major bugfixes (crash):
    - Fix a complicated crash bug that could affect Tor clients
      configured to use bridges when replacing a networkstatus consensus
      in which one of their bridges was mentioned. OpenBSD users saw
      more crashes here, but all platforms were potentially affected.
      Fixes bug 20103; bugfix on 0.2.8.2-alpha.

  o Major bugfixes (relay, OOM handler):
    - Fix a timing-dependent assertion failure that could occur when we
      tried to flush from a circuit after having freed its cells because
      of an out-of-memory condition. Fixes bug 20203; bugfix on
      0.2.8.1-alpha. Thanks to "cypherpunks" for help diagnosing
      this one.

  o Minor feature (fallback directories):
    - Remove 8 fallbacks that are no longer suitable, leaving 81 of the
      100 fallbacks originally introduced in Tor 0.2.8.2-alpha in March
      2016. Closes ticket 20190; patch by teor.

  o Minor features (geoip):
    - Update geoip and geoip6 to the September 6 2016 Maxmind GeoLite2
      Country database.


Changes in version 0.2.9.2-alpha - 2016-08-24
  Tor 0.2.9.2-alpha continues development of the 0.2.9 series with
  several new features and bugfixes. It also includes an important
  authority update and an important bugfix from 0.2.8.7. Everyone who
  sets the ReachableAddresses option, and all bridges, are strongly
  encouraged to upgrade to 0.2.8.7, or to 0.2.9.2-alpha.

  o Directory authority changes (also in 0.2.8.7):
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Major bugfixes (client, security, also in 0.2.8.7):
    - Only use the ReachableAddresses option to restrict the first hop
      in a path. In earlier versions of 0.2.8.x, it would apply to
      every hop in the path, with a possible degradation in anonymity
      for anyone using an uncommon ReachableAddress setting. Fixes bug
      19973; bugfix on 0.2.8.2-alpha.

  o Major features (user interface):
    - Tor now supports the ability to declare options deprecated, so
      that we can recommend that people stop using them. Previously,
      this was done in an ad-hoc way. Closes ticket 19820.

  o Major bugfixes (directory downloads):
    - Avoid resetting download status for consensuses hourly, since we
      already have another, smarter retry mechanism. Fixes bug 8625;
      bugfix on 0.2.0.9-alpha.

  o Minor features (config):
    - Warn users when descriptor and port addresses are inconsistent.
      Mitigates bug 13953; patch by teor.

  o Minor features (geoip):
    - Update geoip and geoip6 to the August 2 2016 Maxmind GeoLite2
      Country database.

  o Minor features (user interface):
    - There is a new --list-deprecated-options command-line option to
      list all of the deprecated options. Implemented as part of
      ticket 19820.

  o Minor bugfixes (code style):
    - Fix an integer signedness conversion issue in the case conversion
      tables. Fixes bug 19168; bugfix on 0.2.1.11-alpha.

  o Minor bugfixes (compilation):
    - Build correctly on versions of libevent2 without support for
      evutil_secure_rng_add_bytes(). Fixes bug 19904; bugfix
      on 0.2.5.4-alpha.
    - Fix a compilation warning on GCC versions before 4.6. Our
      ENABLE_GCC_WARNING macro used the word "warning" as an argument,
      when it is also required as an argument to the compiler pragma.
      Fixes bug 19901; bugfix on 0.2.9.1-alpha.

  o Minor bugfixes (compilation, also in 0.2.8.7):
    - Remove an inappropriate "inline" in tortls.c that was causing
      warnings on older versions of GCC. Fixes bug 19903; bugfix
      on 0.2.8.1-alpha.

  o Minor bugfixes (fallback directories, also in 0.2.8.7):
    - Avoid logging a NULL string pointer when loading fallback
      directory information. Fixes bug 19947; bugfix on 0.2.4.7-alpha
      and 0.2.8.1-alpha. Report and patch by "rubiate".

  o Minor bugfixes (logging):
    - Log a more accurate message when we fail to dump a microdescriptor.
      Fixes bug 17758; bugfix on 0.2.2.8-alpha. Patch from Daniel Pinto.

  o Minor bugfixes (memory leak):
    - Fix a series of slow memory leaks related to parsing torrc files
      and options. Fixes bug 19466; bugfix on 0.2.1.6-alpha.

  o Deprecated features:
    - A number of DNS-cache-related sub-options for client ports are now
      deprecated for security reasons, and may be removed in a future
      version of Tor. (We believe that client-side DNS cacheing is a bad
      idea for anonymity, and you should not turn it on.) The options
      are: CacheDNS, CacheIPv4DNS, CacheIPv6DNS, UseDNSCache,
      UseIPv4Cache, and UseIPv6Cache.
    - A number of options are deprecated for security reasons, and may
      be removed in a future version of Tor. The options are:
      AllowDotExit, AllowInvalidNodes, AllowSingleHopCircuits,
      AllowSingleHopExits, ClientDNSRejectInternalAddresses,
      CloseHSClientCircuitsImmediatelyOnTimeout,
      CloseHSServiceRendCircuitsImmediatelyOnTimeout,
      ExcludeSingleHopRelays, FastFirstHopPK, TLSECGroup,
      UseNTorHandshake, and WarnUnsafeSocks.
    - The *ListenAddress options are now deprecated as unnecessary: the
      corresponding *Port options should be used instead. These options
      may someday be removed. The affected options are:
      ControlListenAddress, DNSListenAddress, DirListenAddress,
      NATDListenAddress, ORListenAddress, SocksListenAddress,
      and TransListenAddress.

  o Documentation:
    - Correct the IPv6 syntax in our documentation for the
      VirtualAddrNetworkIPv6 torrc option. Closes ticket 19743.

  o Removed code:
    - We no longer include the (dead, deprecated) bufferevent code in
      Tor. Closes ticket 19450. Based on a patch from U+039b.


Changes in version 0.2.8.7 - 2016-08-24
  Tor 0.2.8.7 fixes an important bug related to the ReachableAddresses
  option in 0.2.8.6, and replaces a retiring bridge authority. Everyone
  who sets the ReachableAddresses option, and all bridges, are strongly
  encouraged to upgrade.

  o Directory authority changes:
    - The "Tonga" bridge authority has been retired; the new bridge
      authority is "Bifroest". Closes tickets 19728 and 19690.

  o Major bugfixes (client, security):
    - Only use the ReachableAddresses option to restrict the first hop
      in a path. In earlier versions of 0.2.8.x, it would apply to
      every hop in the path, with a possible degradation in anonymity
      for anyone using an uncommon ReachableAddress setting. Fixes bug
      19973; bugfix on 0.2.8.2-alpha.

  o Minor features (geoip):
    - Update geoip and geoip6 to the August 2 2016 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation):
    - Remove an inappropriate "inline" in tortls.c that was causing
      warnings on older versions of GCC. Fixes bug 19903; bugfix
      on 0.2.8.1-alpha.

  o Minor bugfixes (fallback directories):
    - Avoid logging a NULL string pointer when loading fallback
      directory information. Fixes bug 19947; bugfix on 0.2.4.7-alpha
      and 0.2.8.1-alpha. Report and patch by "rubiate".


Changes in version 0.2.9.1-alpha - 2016-08-08
  Tor 0.2.9.1-alpha is the first alpha release in the 0.2.9 development
  series. It improves our support for hardened builds and compiler
  warnings, deploys some critical infrastructure for improvements to
  hidden services, includes a new timing backend that we hope to use for
  better support for traffic padding, makes it easier for programmers to
  log unexpected events, and contains other small improvements to
  security, correctness, and performance.

  Below are the changes since 0.2.8.6.

  o New system requirements:
    - Tor now requires Libevent version 2.0.10-stable or later. Older
      versions of Libevent have less efficient backends for several
      platforms, and lack the DNS code that we use for our server-side
      DNS support. This implements ticket 19554.
    - Tor now requires zlib version 1.2 or later, for security,
      efficiency, and (eventually) gzip support. (Back when we started,
      zlib 1.1 and zlib 1.0 were still found in the wild. 1.2 was
      released in 2003. We recommend the latest version.)

  o Major features (build, hardening):
    - Tor now builds with -ftrapv by default on compilers that support
      it. This option detects signed integer overflow (which C forbids),
      and turns it into a hard-failure. We do not apply this option to
      code that needs to run in constant time to avoid side-channels;
      instead, we use -fwrapv in that code. Closes ticket 17983.
    - When --enable-expensive-hardening is selected, stop applying the
      clang/gcc sanitizers to code that needs to run in constant time.
      Although we are aware of no introduced side-channels, we are not
      able to prove that there are none. Related to ticket 17983.

  o Major features (compilation):
    - Our big list of extra GCC warnings is now enabled by default when
      building with GCC (or with anything like Clang that claims to be
      GCC-compatible). To make all warnings into fatal compilation
      errors, pass --enable-fatal-warnings to configure. Closes
      ticket 19044.
    - Use the Autoconf macro AC_USE_SYSTEM_EXTENSIONS to automatically
      turn on C and POSIX extensions. (Previously, we attempted to do
      this on an ad hoc basis.) Closes ticket 19139.

  o Major features (directory authorities, hidden services):
    - Directory authorities can now perform the shared randomness
      protocol specified by proposal 250. Using this protocol, directory
      authorities generate a global fresh random value every day. In the
      future, this value will be used by hidden services to select
      HSDirs. This release implements the directory authority feature;
      the hidden service side will be implemented in the future as part
      of proposal 224. Resolves ticket 16943; implements proposal 250.

  o Major features (downloading, random exponential backoff):
    - When we fail to download an object from a directory service, wait
      for an (exponentially increasing) randomized amount of time before
      retrying, rather than a fixed interval as we did before. This
      prevents a group of Tor instances from becoming too synchronized,
      or a single Tor instance from becoming too predictable, in its
      download schedule. Closes ticket 15942.

  o Major bugfixes (exit policies):
    - Avoid disclosing exit outbound bind addresses, configured port
      bind addresses, and local interface addresses in relay descriptors
      by default under ExitPolicyRejectPrivate. Instead, only reject
      these (otherwise unlisted) addresses if
      ExitPolicyRejectLocalInterfaces is set. Fixes bug 18456; bugfix on
      0.2.7.2-alpha. Patch by teor.

  o Major bugfixes (hidden service client):
    - Allow Tor clients with appropriate controllers to work with
      FetchHidServDescriptors set to 0. Previously, this option also
      disabled descriptor cache lookup, thus breaking hidden services
      entirely. Fixes bug 18704; bugfix on 0.2.0.20-rc. Patch by "twim".

  o Minor features (build, hardening):
    - Detect and work around a libclang_rt problem that would prevent
      clang from finding __mulodi4() on some 32-bit platforms, and thus
      keep -ftrapv from linking on those systems. Closes ticket 19079.
    - When building on a system without runtime support for the runtime
      hardening options, try to log a useful warning at configuration
      time, rather than an incomprehensible warning at link time. If
      expensive hardening was requested, this warning becomes an error.
      Closes ticket 18895.

  o Minor features (code safety):
    - In our integer-parsing functions, ensure that maxiumum value we
      give is no smaller than the minimum value. Closes ticket 19063;
      patch from U+039b.

  o Minor features (controller):
    - Implement new GETINFO queries for all downloads that use
      download_status_t to schedule retries. This allows controllers to
      examine the schedule for pending downloads. Closes ticket 19323.
    - Allow controllers to configure basic client authorization on
      hidden services when they create them with the ADD_ONION control
      command. Implements ticket 15588. Patch by "special".
    - Fire a STATUS_SERVER controller event whenever the hibernation
      status changes between "awake"/"soft"/"hard". Closes ticket 18685.

  o Minor features (directory authority):
    - Directory authorities now only give the Guard flag to a relay if
      they are also giving it the Stable flag. This change allows us to
      simplify path selection for clients. It should have minimal effect
      in practice, since >99% of Guards already have the Stable flag.
      Implements ticket 18624.
    - Directory authorities now write their v3-status-votes file out to
      disk earlier in the consensus process, so we have a record of the
      votes even if we abort the consensus process. Resolves
      ticket 19036.

  o Minor features (hidden service):
    - Stop being so strict about the payload length of "rendezvous1"
      cells. We used to be locked in to the "TAP" handshake length, and
      now we can handle better handshakes like "ntor". Resolves
      ticket 18998.

  o Minor features (infrastructure, time):
    - Tor now uses the operating system's monotonic timers (where
      available) for internal fine-grained timing. Previously we would
      look at the system clock, and then attempt to compensate for the
      clock running backwards. Closes ticket 18908.
    - Tor now includes an improved timer backend, so that we can
      efficiently support tens or hundreds of thousands of concurrent
      timers, as will be needed for some of our planned anti-traffic-
      analysis work. This code is based on William Ahern's "timeout.c"
      project, which implements a "tickless hierarchical timing wheel".
      Closes ticket 18365.

  o Minor features (logging):
    - Provide a more useful warning message when configured with an
      invalid Nickname. Closes ticket 18300; patch from "icanhasaccount".
    - When dumping unparseable router descriptors, optionally store them
      in separate files, named by digest, up to a configurable size
      limit. You can change the size limit by setting the
      MaxUnparseableDescSizeToLog option, and disable this feature by
      setting that option to 0. Closes ticket 18322.
    - Add a set of macros to check nonfatal assertions, for internal
      use. Migrating more of our checks to these should help us avoid
      needless crash bugs. Closes ticket 18613.

  o Minor features (performance):
    - Changer the "optimistic data" extension from "off by default" to
      "on by default". The default was ordinarily overridden by a
      consensus option, but when clients were bootstrapping for the
      first time, they would not have a consensus to get the option
      from. Changing this default When fetching a consensus for the
      first time, use optimistic data. This saves a round-trip during
      startup. Closes ticket 18815.

  o Minor features (relay, usability):
    - When the directory authorities refuse a bad relay's descriptor,
      encourage the relay operator to contact us. Many relay operators
      won't notice this line in their logs, but it's a win if even a few
      learn why we don't like what their relay was doing. Resolves
      ticket 18760.

  o Minor features (testing):
    - Let backtrace tests work correctly under AddressSanitizer. Fixes
      part of bug 18934; bugfix on 0.2.5.2-alpha.
    - Move the test-network.sh script to chutney, and modify tor's test-
      network.sh to call the (newer) chutney version when available.
      Resolves ticket 19116. Patch by teor.
    - Use the lcov convention for marking lines as unreachable, so that
      we don't count them when we're generating test coverage data.
      Update our coverage tools to understand this convention. Closes
      ticket 16792.

  o Minor bugfixes (bootstrap):
    - Remember the directory we fetched the consensus or previous
      certificates from, and use it to fetch future authority
      certificates. This change improves bootstrapping performance.
      Fixes bug 18963; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (build):
    - The test-stem and test-network makefile targets now depend only on
      the tor binary that they are testing. Previously, they depended on
      "make all". Fixes bug 18240; bugfix on 0.2.8.2-alpha. Based on a
      patch from "cypherpunks".

  o Minor bugfixes (circuits):
    - Make sure extend_info_from_router() is only called on servers.
      Fixes bug 19639; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (compilation):
    - When building with Clang, use a full set of GCC warnings.
      (Previously, we included only a subset, because of the way we
      detected them.) Fixes bug 19216; bugfix on 0.2.0.1-alpha.

  o Minor bugfixes (directory authority):
    - Authorities now sort the "package" lines in their votes, for ease
      of debugging. (They are already sorted in consensus documents.)
      Fixes bug 18840; bugfix on 0.2.6.3-alpha.
    - When parsing a detached signature, make sure we use the length of
      the digest algorithm instead of an hardcoded DIGEST256_LEN in
      order to avoid comparing bytes out-of-bounds with a smaller digest
      length such as SHA1. Fixes bug 19066; bugfix on 0.2.2.6-alpha.

  o Minor bugfixes (documentation):
    - Document the --passphrase-fd option in the tor manpage. Fixes bug
      19504; bugfix on 0.2.7.3-rc.
    - Fix the description of the --passphrase-fd option in the
      tor-gencert manpage. The option is used to pass the number of a
      file descriptor to read the passphrase from, not to read the file
      descriptor from. Fixes bug 19505; bugfix on 0.2.0.20-alpha.

  o Minor bugfixes (ephemeral hidden service):
    - When deleting an ephemeral hidden service, close its intro points
      even if they are not completely open. Fixes bug 18604; bugfix
      on 0.2.7.1-alpha.

  o Minor bugfixes (guard selection):
    - Use a single entry guard even if the NumEntryGuards consensus
      parameter is not provided. Fixes bug 17688; bugfix
      on 0.2.5.6-alpha.
    - Don't mark guards as unreachable if connection_connect() fails.
      That function fails for local reasons, so it shouldn't reveal
      anything about the status of the guard. Fixes bug 14334; bugfix
      on 0.2.3.10-alpha.

  o Minor bugfixes (hidden service client):
    - Increase the minimum number of internal circuits we preemptively
      build from 2 to 3, so a circuit is available when a client
      connects to another onion service. Fixes bug 13239; bugfix
      on 0.1.0.1-rc.

  o Minor bugfixes (logging):
    - When logging a directory ownership mismatch, log the owning
      username correctly. Fixes bug 19578; bugfix on 0.2.2.29-beta.

  o Minor bugfixes (memory leaks):
    - Fix a small, uncommon memory leak that could occur when reading a
      truncated ed25519 key file. Fixes bug 18956; bugfix
      on 0.2.6.1-alpha.

  o Minor bugfixes (testing):
    - Allow clients to retry HSDirs much faster in test networks. Fixes
      bug 19702; bugfix on 0.2.7.1-alpha. Patch by teor.
    - Disable ASAN's detection of segmentation faults while running
      test_bt.sh, so that we can make sure that our own backtrace
      generation code works. Fixes another aspect of bug 18934; bugfix
      on 0.2.5.2-alpha. Patch from "cypherpunks".
    - Fix the test-network-all target on out-of-tree builds by using the
      correct path to the test driver script. Fixes bug 19421; bugfix
      on 0.2.7.3-rc.

  o Minor bugfixes (time):
    - Improve overflow checks in tv_udiff and tv_mdiff. Fixes bug 19483;
      bugfix on all released tor versions.
    - When computing the difference between two times in milliseconds,
      we now round to the nearest millisecond correctly. Previously, we
      could sometimes round in the wrong direction. Fixes bug 19428;
      bugfix on 0.2.2.2-alpha.

  o Minor bugfixes (user interface):
    - Display a more accurate number of suppressed messages in the log
      rate-limiter. Previously, there was a potential integer overflow
      in the counter. Now, if the number of messages hits a maximum, the
      rate-limiter doesn't count any further. Fixes bug 19435; bugfix
      on 0.2.4.11-alpha.
    - Fix a typo in the passphrase prompt for the ed25519 identity key.
      Fixes bug 19503; bugfix on 0.2.7.2-alpha.

  o Code simplification and refactoring:
    - Remove redundant declarations of the MIN macro. Closes
      ticket 18889.
    - Rename tor_dup_addr() to tor_addr_to_str_dup() to avoid confusion.
      Closes ticket 18462; patch from "icanhasaccount".
    - Split the 600-line directory_handle_command_get function into
      separate functions for different URL types. Closes ticket 16698.

  o Documentation:
    - Fix spelling of "--enable-tor2web-mode" in the manpage. Closes
      ticket 19153. Patch from "U+039b".

  o Removed features:
    - Remove support for "GET /tor/bytes.txt" DirPort request, and
      "GETINFO dir-usage" controller request, which were only available
      via a compile-time option in Tor anyway. Feature was added in
      0.2.2.1-alpha. Resolves ticket 19035.
    - There is no longer a compile-time option to disable support for
      TransPort. (If you don't want TransPort; just don't use it.) Patch
      from "U+039b". Closes ticket 19449.

  o Testing:
    - Run more workqueue tests as part of "make check". These had
      previously been implemented, but you needed to know special
      command-line options to enable them.
    - We now have unit tests for our code to reject zlib "compression
      bombs". (Fortunately, the code works fine.)


Changes in version 0.2.8.6 - 2016-08-02

  Tor 0.2.8.6 is the first stable version of the Tor 0.2.8 series.

  The Tor 0.2.8 series improves client bootstrapping performance,
  completes the authority-side implementation of improved identity
  keys for relays, and includes numerous bugfixes and performance
  improvements throughout the program. This release continues to
  improve the coverage of Tor's test suite.  For a full list of
  changes since Tor 0.2.7, see the ReleaseNotes file.

  Changes since 0.2.8.5-rc:

  o Minor features (geoip):
    - Update geoip and geoip6 to the July 6 2016 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation):
    - Fix a compilation warning in the unit tests on systems where char
      is signed. Fixes bug 19682; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (fallback directories):
    - Remove 1 fallback that was on the hardcoded list, then opted-out,
      leaving 89 of the 100 fallbacks originally introduced in Tor
      0.2.8.2-alpha in March 2016. Closes ticket 19782; patch by teor.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Allow more syscalls when running with "Sandbox 1" enabled:
      sysinfo, getsockopt(SO_SNDBUF), and setsockopt(SO_SNDBUFFORCE). On
      some systems, these are required for Tor to start. Fixes bug
      18397; bugfix on 0.2.5.1-alpha. Patch from Daniel Pinto.
    - Allow IPPROTO_UDP datagram sockets when running with "Sandbox 1",
      so that get_interface_address6_via_udp_socket_hack() can work.
      Fixes bug 19660; bugfix on 0.2.5.1-alpha.


Changes in version 0.2.8.5-rc - 2016-07-07
  Tor 0.2.8.5-rc is the second release candidate in the Tor 0.2.8
  series. If we find no new bugs or regressions here, the first stable
  0.2.8 release will be identical to it. It has a few small bugfixes
  against previous versions.

  o Directory authority changes:
    - Urras is no longer a directory authority. Closes ticket 19271.

  o Major bugfixes (heartbeat):
    - Fix a regression that would crash Tor when the periodic
      "heartbeat" log messages were disabled. Fixes bug 19454; bugfix on
      0.2.8.1-alpha. Reported by "kubaku".

  o Minor features (build):
    - Tor now again builds with the recent OpenSSL 1.1 development
      branch (tested against 1.1.0-pre6-dev). Closes ticket 19499.
    - When building manual pages, set the timezone to "UTC", so that the
      output is reproducible. Fixes bug 19558; bugfix on 0.2.2.9-alpha.
      Patch from intrigeri.

  o Minor bugfixes (fallback directory selection):
    - Avoid errors during fallback selection if there are no eligible
      fallbacks. Fixes bug 19480; bugfix on 0.2.8.3-alpha. Patch
      by teor.

  o Minor bugfixes (IPv6, microdescriptors):
    - Don't check node addresses when we only have a routerstatus. This
      allows IPv6-only clients to bootstrap by fetching microdescriptors
      from fallback directory mirrors. (The microdescriptor consensus
      has no IPv6 addresses in it.) Fixes bug 19608; bugfix
      on 0.2.8.2-alpha.

  o Minor bugfixes (logging):
    - Reduce pointlessly verbose log messages when directory servers
      can't be found. Fixes bug 18849; bugfix on 0.2.8.3-alpha and
      0.2.8.1-alpha. Patch by teor.
    - When a fallback directory changes its fingerprint from the hard-
      coded fingerprint, log a less severe, more explanatory log
      message. Fixes bug 18812; bugfix on 0.2.8.1-alpha. Patch by teor.

  o Minor bugfixes (Linux seccomp2 sandboxing):
    - Allow statistics to be written to disk when "Sandbox 1" is
      enabled. Fixes bugs 19556 and 19957; bugfix on 0.2.5.1-alpha and
      0.2.6.1-alpha respectively.

  o Minor bugfixes (user interface):
    - Remove a warning message "Service [scrubbed] not found after
      descriptor upload". This message appears when one uses HSPOST
      control command to upload a service descriptor. Since there is
      only a descriptor and no service, showing this message is
      pointless and confusing. Fixes bug 19464; bugfix on 0.2.7.2-alpha.

  o Fallback directory list:
    - Add a comment to the generated fallback directory list that
      explains how to comment out unsuitable fallbacks in a way that's
      compatible with the stem fallback parser.
    - Update fallback whitelist and blacklist based on relay operator
      emails. Blacklist unsuitable (non-working, over-volatile)
      fallbacks. Resolves ticket 19071. Patch by teor.
    - Remove 10 unsuitable fallbacks, leaving 90 of the 100 fallbacks
      originally introduced in Tor 0.2.8.2-alpha in March 2016. Closes
      ticket 19071; patch by teor.


Changes in version 0.2.8.4-rc - 2016-06-15
  Tor 0.2.8.4-rc is the first release candidate in the Tor 0.2.8 series.
  If we find no new bugs or regressions here, the first stable 0.2.8
  release will be identical to it. It has a few small bugfixes against
  previous versions.

  o Major bugfixes (user interface):
    - Correctly give a warning in the cases where a relay is specified
      by nickname, and one such relay is found, but it is not officially
      Named. Fixes bug 19203; bugfix on 0.2.3.1-alpha.

  o Minor features (build):
    - Tor now builds once again with the recent OpenSSL 1.1 development
      branch (tested against 1.1.0-pre5 and 1.1.0-pre6-dev).

  o Minor features (geoip):
    - Update geoip and geoip6 to the June 7 2016 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation):
    - Cause the unit tests to compile correctly on mingw64 versions that
      lack sscanf. Fixes bug 19213; bugfix on 0.2.7.1-alpha.

  o Minor bugfixes (downloading):
    - Predict more correctly whether we'll be downloading over HTTP when
      we determine the maximum length of a URL. This should avoid a
      "BUG" warning about the Squid HTTP proxy and its URL limits. Fixes
      bug 19191.


Changes in version 0.2.8.3-alpha - 2016-05-26
  Tor 0.2.8.3-alpha resolves several bugs, most of them introduced over
  the course of the 0.2.8 development cycle. It improves the behavior of
  directory clients, fixes several crash bugs, fixes a gap in compiler
  hardening, and allows the full integration test suite to run on
  more platforms.

  o Major bugfixes (security, client, DNS proxy):
    - Stop a crash that could occur when a client running with DNSPort
      received a query with multiple address types, and the first
      address type was not supported. Found and fixed by Scott Dial.
      Fixes bug 18710; bugfix on 0.2.5.4-alpha.

  o Major bugfixes (security, compilation):
    - Correctly detect compiler flags on systems where _FORTIFY_SOURCE
      is predefined. Previously, our use of -D_FORTIFY_SOURCE would
      cause a compiler warning, thereby making other checks fail, and
      needlessly disabling compiler-hardening support. Fixes one case of
      bug 18841; bugfix on 0.2.3.17-beta. Patch from "trudokal".

  o Major bugfixes (security, directory authorities):
    - Fix a crash and out-of-bounds write during authority voting, when
      the list of relays includes duplicate ed25519 identity keys. Fixes
      bug 19032; bugfix on 0.2.8.2-alpha.

  o Major bugfixes (client, bootstrapping):
    - Check if bootstrap consensus downloads are still needed when the
      linked connection attaches. This prevents tor making unnecessary
      begindir-style connections, which are the only directory
      connections tor clients make since the fix for 18483 was merged.
    - Fix some edge cases where consensus download connections may not
      have been closed, even though they were not needed. Related to fix
      for 18809.
    - Make relays retry consensus downloads the correct number of times,
      rather than the more aggressive client retry count. Fixes part of
      ticket 18809.
    - Stop downloading consensuses when we have a consensus, even if we
      don't have all the certificates for it yet. Fixes bug 18809;
      bugfix on 0.2.8.1-alpha. Patches by arma and teor.

  o Major bugfixes (directory mirrors):
    - Decide whether to advertise begindir support in the the same way
      we decide whether to advertise our DirPort. Allowing these
      decisions to become out-of-sync led to surprising behavior like
      advertising begindir support when hibernation made us not
      advertise a DirPort. Resolves bug 18616; bugfix on 0.2.8.1-alpha.
      Patch by teor.

  o Major bugfixes (IPv6 bridges, client):
    - Actually use IPv6 addresses when selecting directory addresses for
      IPv6 bridges. Fixes bug 18921; bugfix on 0.2.8.1-alpha. Patch
      by "teor".

  o Major bugfixes (key management):
    - If OpenSSL fails to generate an RSA key, do not retain a dangling
      pointer to the previous (uninitialized) key value. The impact here
      should be limited to a difficult-to-trigger crash, if OpenSSL is
      running an engine that makes key generation failures possible, or
      if OpenSSL runs out of memory. Fixes bug 19152; bugfix on
      0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and
      Baishakhi Ray.

  o Major bugfixes (testing):
    - Fix a bug that would block 'make test-network-all' on systems where
      IPv6 packets were lost. Fixes bug 19008; bugfix on 0.2.7.3-rc.
    - Avoid "WSANOTINITIALISED" warnings in the unit tests. Fixes bug 18668;
      bugfix on 0.2.8.1-alpha.

  o Minor features (clients):
    - Make clients, onion services, and bridge relays always use an
      encrypted begindir connection for directory requests. Resolves
      ticket 18483. Patch by "teor".

  o Minor features (fallback directory mirrors):
    - Give each fallback the same weight for client selection; restrict
      fallbacks to one per operator; report fallback directory detail
      changes when rebuilding list; add new fallback directory mirrors
      to the whitelist; and many other minor simplifications and fixes.
      Closes tasks 17905, 18749, bug 18689, and fixes part of bug 18812 on
      0.2.8.1-alpha; patch by "teor".
    - Replace the 21 fallbacks generated in January 2016 and included in
      Tor 0.2.8.1-alpha, with a list of 100 fallbacks generated in March
      2016. Closes task 17158; patch by "teor".

  o Minor features (geoip):
    - Update geoip and geoip6 to the May 4 2016 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (assert, portability):
    - Fix an assertion failure in memarea.c on systems where "long" is
      shorter than the size of a pointer. Fixes bug 18716; bugfix
      on 0.2.1.1-alpha.

  o Minor bugfixes (bootstrap):
    - Consistently use the consensus download schedule for authority
      certificates. Fixes bug 18816; bugfix on 0.2.4.13-alpha.

  o Minor bugfixes (build):
    - Remove a pair of redundant AM_CONDITIONAL declarations from
      configure.ac. Fixes one final case of bug 17744; bugfix
      on 0.2.8.2-alpha.
    - Resolve warnings when building on systems that are concerned with
      signed char. Fixes bug 18728; bugfix on 0.2.7.2-alpha
      and 0.2.6.1-alpha.
    - When libscrypt.h is found, but no libscrypt library can be linked,
      treat libscrypt as absent. Fixes bug 19161; bugfix
      on 0.2.6.1-alpha.

  o Minor bugfixes (client):
    - Turn all TestingClientBootstrap* into non-testing torrc options.
      This changes simply renames them by removing "Testing" in front of
      them and they do not require TestingTorNetwork to be enabled
      anymore. Fixes bug 18481; bugfix on 0.2.8.1-alpha.
    - Make directory node selection more reliable, mainly for IPv6-only
      clients and clients with few reachable addresses. Fixes bug 18929;
      bugfix on 0.2.8.1-alpha. Patch by "teor".

  o Minor bugfixes (controller, microdescriptors):
    - Make GETINFO dir/status-vote/current/consensus conform to the
      control specification by returning "551 Could not open cached
      consensus..." when not caching consensuses. Fixes bug 18920;
      bugfix on 0.2.2.6-alpha.

  o Minor bugfixes (crypto, portability):
    - The SHA3 and SHAKE routines now produce the correct output on Big
      Endian systems. No code calls either algorithm yet, so this is
      primarily a build fix. Fixes bug 18943; bugfix on 0.2.8.1-alpha.
    - Tor now builds again with the recent OpenSSL 1.1 development
      branch (tested against 1.1.0-pre4 and 1.1.0-pre5-dev). Closes
      ticket 18286.

  o Minor bugfixes (directories):
    - When fetching extrainfo documents, compare their SHA256 digests
      and Ed25519 signing key certificates with the routerinfo that led
      us to fetch them, rather than with the most recent routerinfo.
      Otherwise we generate many spurious warnings about mismatches.
      Fixes bug 17150; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (logging):
    - When we can't generate a signing key because OfflineMasterKey is
      set, do not imply that we should have been able to load it. Fixes
      bug 18133; bugfix on 0.2.7.2-alpha.
    - Stop periodic_event_dispatch() from blasting twelve lines per
      second at loglevel debug. Fixes bug 18729; fix on 0.2.8.1-alpha.
    - When rejecting a misformed INTRODUCE2 cell, only log at
      PROTOCOL_WARN severity. Fixes bug 18761; bugfix on 0.2.8.2-alpha.

  o Minor bugfixes (pluggable transports):
    - Avoid reporting a spurious error when we decide that we don't need
      to terminate a pluggable transport because it has already exited.
      Fixes bug 18686; bugfix on 0.2.5.5-alpha.

  o Minor bugfixes (pointer arithmetic):
    - Fix a bug in memarea_alloc() that could have resulted in remote
      heap write access, if Tor had ever passed an unchecked size to
      memarea_alloc(). Fortunately, all the sizes we pass to
      memarea_alloc() are pre-checked to be less than 128 kilobytes.
      Fixes bug 19150; bugfix on 0.2.1.1-alpha. Bug found by
      Guido Vranken.

  o Minor bugfixes (relays):
    - Consider more config options when relays decide whether to
      regenerate their descriptor. Fixes more of bug 12538; bugfix
      on 0.2.8.1-alpha.
    - Resolve some edge cases where we might launch an ORPort
      reachability check even when DisableNetwork is set. Noticed while
      fixing bug 18616; bugfix on 0.2.3.9-alpha.

  o Minor bugfixes (statistics):
    - We now include consensus downloads via IPv6 in our directory-
      request statistics. Fixes bug 18460; bugfix on 0.2.3.14-alpha.

  o Minor bugfixes (testing):
    - Allow directories in small networks to bootstrap by skipping
      DirPort checks when the consensus has no exits. Fixes bug 19003;
      bugfix on 0.2.8.1-alpha. Patch by teor.
    - Fix a small memory leak that would occur when the
      TestingEnableCellStatsEvent option was turned on. Fixes bug 18673;
      bugfix on 0.2.5.2-alpha.

  o Minor bugfixes (time handling):
    - When correcting a corrupt 'struct tm' value, fill in the tm_wday
      field. Otherwise, our unit tests crash on Windows. Fixes bug
      18977; bugfix on 0.2.2.25-alpha.

  o Documentation:
    - Document the contents of the 'datadir/keys' subdirectory in the
      manual page. Closes ticket 17621.
    - Stop recommending use of nicknames to identify relays in our
      MapAddress documentation. Closes ticket 18312.


Changes in version 0.2.8.2-alpha - 2016-03-28
  Tor 0.2.8.2-alpha is the second alpha in its series. It fixes numerous
  bugs in earlier versions of Tor, including some that prevented
  authorities using Tor 0.2.7.x from running correctly. IPv6 and
  directory support should also be much improved.

  o New system requirements:
    - Tor no longer supports versions of OpenSSL with a broken
      implementation of counter mode. (This bug was present in OpenSSL
      1.0.0, and was fixed in OpenSSL 1.0.0a.) Tor still detects, but no
      longer runs with, these versions.
    - Tor no longer attempts to support platforms where the "time_t"
      type is unsigned. (To the best of our knowledge, only OpenVMS does
      this, and Tor has never actually built on OpenVMS.) Closes
      ticket 18184.
    - Tor now uses Autoconf version 2.63 or later, and Automake 1.11 or
      later (released in 2008 and 2009 respectively). If you are
      building Tor from the git repository instead of from the source
      distribution, and your tools are older than this, you will need to
      upgrade. Closes ticket 17732.

  o Major bugfixes (security, pointers):
    - Avoid a difficult-to-trigger heap corruption attack when extending
      a smartlist to contain over 16GB of pointers. Fixes bug 18162;
      bugfix on 0.1.1.11-alpha, which fixed a related bug incompletely.
      Reported by Guido Vranken.

  o Major bugfixes (bridges, pluggable transports):
    - Modify the check for OR connections to private addresses. Allow
      bridges on private addresses, including pluggable transports that
      ignore the (potentially private) address in the bridge line. Fixes
      bug 18517; bugfix on 0.2.8.1-alpha. Reported by gk, patch by teor.

  o Major bugfixes (compilation):
    - Repair hardened builds under the clang compiler. Previously, our
      use of _FORTIFY_SOURCE would conflict with clang's address
      sanitizer. Fixes bug 14821; bugfix on 0.2.5.4-alpha.

  o Major bugfixes (crash on shutdown):
    - Correctly handle detaching circuits from muxes when shutting down.
      Fixes bug 18116; bugfix on 0.2.8.1-alpha.
    - Fix an assert-on-exit bug related to counting memory usage in
      rephist.c. Fixes bug 18651; bugfix on 0.2.8.1-alpha.

  o Major bugfixes (crash on startup):
    - Fix a segfault during startup: If a Unix domain socket was
      configured as listener (such as a ControlSocket or a SocksPort
      "unix:" socket), and tor was started as root but not configured to
      switch to another user, tor would segfault while trying to string
      compare a NULL value. Fixes bug 18261; bugfix on 0.2.8.1-alpha.
      Patch by weasel.

  o Major bugfixes (dns proxy mode, crash):
    - Avoid crashing when running as a DNS proxy. Fixes bug 16248;
      bugfix on 0.2.0.1-alpha. Patch from "cypherpunks".

  o Major bugfixes (relays, bridge clients):
    - Ensure relays always allow IPv4 OR and Dir connections. Ensure
      bridge clients use the address configured in the bridge line.
      Fixes bug 18348; bugfix on 0.2.8.1-alpha. Reported by sysrqb,
      patch by teor.

  o Major bugfixes (voting):
    - Actually enable support for authorities to match routers by their
      Ed25519 identities. Previously, the code had been written, but
      some debugging code that had accidentally been left in the
      codebase made it stay turned off. Fixes bug 17702; bugfix
      on 0.2.7.2-alpha.
    - When collating votes by Ed25519 identities, authorities now
      include a "NoEdConsensus" flag if the ed25519 value (or lack
      thereof) for a server does not reflect the majority consensus.
      Related to bug 17668; bugfix on 0.2.7.2-alpha.
    - When generating a vote with keypinning disabled, never include two
      entries for the same ed25519 identity. This bug was causing
      authorities to generate votes that they could not parse when a
      router violated key pinning by changing its RSA identity but
      keeping its Ed25519 identity. Fixes bug 17668; fixes part of bug
      18318. Bugfix on 0.2.7.2-alpha.

  o Minor features (security, win32):
    - Set SO_EXCLUSIVEADDRUSE on Win32 to avoid a local port-stealing
      attack. Fixes bug 18123; bugfix on all tor versions. Patch
      by teor.

  o Minor features (bug-resistance):
    - Make Tor survive errors involving connections without a
      corresponding event object. Previously we'd fail with an
      assertion; now we produce a log message. Related to bug 16248.

  o Minor features (build):
    - Detect systems with FreeBSD-derived kernels (such as GNU/kFreeBSD)
      as having possible IPFW support. Closes ticket 18448. Patch from
      Steven Chamberlain.

  o Minor features (code hardening):
    - Use tor_snprintf() and tor_vsnprintf() even in external and low-
      level code, to harden against accidental failures to NUL-
      terminate. Part of ticket 17852. Patch from jsturgix. Found
      with Flawfinder.

  o Minor features (crypto):
    - Validate the hard-coded Diffie-Hellman parameters and ensure that
      p is a safe prime, and g is a suitable generator. Closes
      ticket 18221.

  o Minor features (geoip):
    - Update geoip and geoip6 to the March 3 2016 Maxmind GeoLite2
      Country database.

  o Minor features (hidden service directory):
    - Streamline relay-side hsdir handling: when relays consider whether
      to accept an uploaded hidden service descriptor, they no longer
      check whether they are one of the relays in the network that is
      "supposed" to handle that descriptor. Implements ticket 18332.

  o Minor features (IPv6):
    - Add ClientPreferIPv6DirPort, which is set to 0 by default. If set
      to 1, tor prefers IPv6 directory addresses.
    - Add ClientUseIPv4, which is set to 1 by default. If set to 0, tor
      avoids using IPv4 for client OR and directory connections.
    - Try harder to obey the IP version restrictions "ClientUseIPv4 0",
      "ClientUseIPv6 0", "ClientPreferIPv6ORPort", and
      "ClientPreferIPv6DirPort". Closes ticket 17840; patch by teor.

  o Minor features (linux seccomp2 sandbox):
    - Reject attempts to change our Address with "Sandbox 1" enabled.
      Changing Address with Sandbox turned on would never actually work,
      but previously it would fail in strange and confusing ways. Found
      while fixing 18548.

  o Minor features (robustness):
    - Exit immediately with an error message if the code attempts to use
      Libevent without having initialized it. This should resolve some
      frequently-made mistakes in our unit tests. Closes ticket 18241.

  o Minor features (unix domain sockets):
    - Add a new per-socket option, RelaxDirModeCheck, to allow creating
      Unix domain sockets without checking the permissions on the parent
      directory. (Tor checks permissions by default because some
      operating systems only check permissions on the parent directory.
      However, some operating systems do look at permissions on the
      socket, and tor's default check is unneeded.) Closes ticket 18458.
      Patch by weasel.

  o Minor bugfixes (exit policies, security):
    - Refresh an exit relay's exit policy when interface addresses
      change. Previously, tor only refreshed the exit policy when the
      configured external address changed. Fixes bug 18208; bugfix on
      0.2.7.3-rc. Patch by teor.

  o Minor bugfixes (security, hidden services):
    - Prevent hidden services connecting to client-supplied rendezvous
      addresses that are reserved as internal or multicast. Fixes bug
      8976; bugfix on 0.2.3.21-rc. Patch by dgoulet and teor.

  o Minor bugfixes (build):
    - Do not link the unit tests against both the testing and non-
      testing versions of the static libraries. Fixes bug 18490; bugfix
      on 0.2.7.1-alpha.
    - Avoid spurious failures from configure files related to calling
      exit(0) in TOR_SEARCH_LIBRARY. Fixes bug 18626; bugfix on
      0.2.0.1-alpha. Patch from "cypherpunks".
    - Silence spurious clang-scan warnings in the ed25519_donna code by
      explicitly initializing some objects. Fixes bug 18384; bugfix on
      0.2.7.2-alpha. Patch by teor.

  o Minor bugfixes (client, bootstrap):
    - Count receipt of new microdescriptors as progress towards
      bootstrapping. Previously, with EntryNodes set, Tor might not
      successfully repopulate the guard set on bootstrapping. Fixes bug
      16825; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (code correctness):
    - Update to the latest version of Trunnel, which tries harder to
      avoid generating code that can invoke memcpy(p,NULL,0). Bug found
      by clang address sanitizer. Fixes bug 18373; bugfix
      on 0.2.7.2-alpha.

  o Minor bugfixes (configuration):
    - Fix a tiny memory leak when parsing a port configuration ending in
      ":auto". Fixes bug 18374; bugfix on 0.2.3.3-alpha.

  o Minor bugfixes (containers):
    - If we somehow attempt to construct a heap with more than
      1073741822 elements, avoid an integer overflow when maintaining
      the heap property. Fixes bug 18296; bugfix on 0.1.2.1-alpha.

  o Minor bugfixes (correctness):
    - Fix a bad memory handling bug that would occur if we had queued a
      cell on a channel's incoming queue. Fortunately, we can't actually
      queue a cell like that as our code is constructed today, but it's
      best to avoid this kind of error, even if there isn't any code
      that triggers it today. Fixes bug 18570; bugfix on 0.2.4.4-alpha.

  o Minor bugfixes (directory):
    - When generating a URL for a directory server on an IPv6 address,
      wrap the IPv6 address in square brackets. Fixes bug 18051; bugfix
      on 0.2.3.9-alpha. Patch from Malek.

  o Minor bugfixes (fallback directory mirrors):
    - When requesting extrainfo descriptors from a trusted directory
      server, check whether it is an authority or a fallback directory
      which supports extrainfo descriptors. Fixes bug 18489; bugfix on
      0.2.4.7-alpha. Reported by atagar, patch by teor.

  o Minor bugfixes (hidden service, client):
    - Handle the case where the user makes several fast consecutive
      requests to the same .onion address. Previously, the first six
      requests would each trigger a descriptor fetch, each picking a
      directory (there are 6 overall) and the seventh one would fail
      because no directories were left, thereby triggering a close on
      all current directory connections asking for the hidden service.
      The solution here is to not close the connections if we have
      pending directory fetches. Fixes bug 15937; bugfix
      on 0.2.7.1-alpha.

  o Minor bugfixes (hidden service, control port):
    - Add the onion address to the HS_DESC event for the UPLOADED action
      both on success or failure. It was previously hardcoded with
      UNKNOWN. Fixes bug 16023; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (hidden service, directory):
    - Bridges now refuse "rendezvous2" (hidden service descriptor)
      publish attempts. Suggested by ticket 18332.

  o Minor bugfixes (linux seccomp2 sandbox):
    - Allow the setrlimit syscall, and the prlimit and prlimit64
      syscalls, which some libc implementations use under the hood.
      Fixes bug 15221; bugfix on 0.2.5.1-alpha.
    - Avoid a 10-second delay when starting as a client with "Sandbox 1"
      enabled and no DNS resolvers configured. This should help TAILS
      start up faster. Fixes bug 18548; bugfix on 0.2.5.1-alpha.
    - Fix the sandbox's interoperability with unix domain sockets under
      setuid. Fixes bug 18253; bugfix on 0.2.8.1-alpha.

  o Minor bugfixes (logging):
    - When logging information about an unparsable networkstatus vote or
      consensus, do not say "vote" when we mean consensus. Fixes bug
      18368; bugfix on 0.2.0.8-alpha.
    - Scrub service name in "unrecognized service ID" log messages.
      Fixes bug 18600; bugfix on 0.2.4.11-alpha.
    - Downgrade logs and backtraces about IP versions to info-level.
      Only log backtraces once each time tor runs. Assists in diagnosing
      bug 18351; bugfix on 0.2.8.1-alpha. Reported by sysrqb and
      Christian, patch by teor.

  o Minor bugfixes (memory safety):
    - Avoid freeing an uninitialized pointer when opening a socket fails
      in get_interface_addresses_ioctl(). Fixes bug 18454; bugfix on
      0.2.3.11-alpha. Reported by toralf and "cypherpunks", patch
      by teor.
    - Correctly duplicate addresses in get_interface_address6_list().
      Fixes bug 18454; bugfix on 0.2.8.1-alpha. Reported by toralf,
      patch by "cypherpunks".
    - Fix a memory leak in tor-gencert. Fixes part of bug 18672; bugfix
      on 0.2.0.1-alpha.
    - Fix a memory leak in "tor --list-fingerprint". Fixes part of bug
      18672; bugfix on 0.2.5.1-alpha.

  o Minor bugfixes (private directory):
    - Prevent a race condition when creating private directories. Fixes
      part of bug 17852; bugfix on 0.0.2pre13. Part of ticket 17852.
      Patch from jsturgix. Found with Flawfinder.

  o Minor bugfixes (test networks, IPv6):
    - Allow internal IPv6 addresses in descriptors in test networks.
      Fixes bug 17153; bugfix on 0.2.3.16-alpha. Patch by teor, reported
      by karsten.

  o Minor bugfixes (testing):
    - We no longer disable assertions in the unit tests when coverage is
      enabled. Instead, we require you to say --disable-asserts-in-tests
      to the configure script if you need assertions disabled in the
      unit tests (for example, if you want to perform branch coverage).
      Fixes bug 18242; bugfix on 0.2.7.1-alpha.

  o Minor bugfixes (time parsing):
    - Avoid overflow in tor_timegm when parsing dates in and after 2038
      on platforms with 32-bit time_t. Fixes bug 18479; bugfix on
      0.0.2pre14. Patch by teor.

  o Minor bugfixes (tor-gencert):
    - Correctly handle the case where an authority operator enters a
      passphrase but sends an EOF before sending a newline. Fixes bug
      17443; bugfix on 0.2.0.20-rc. Found by junglefowl.

  o Code simplification and refactoring:
    - Quote all the string interpolations in configure.ac -- even those
      which we are pretty sure can't contain spaces. Closes ticket
      17744. Patch from zerosion.
    - Remove specialized code for non-inplace AES_CTR. 99% of our AES is
      inplace, so there's no need to have a separate implementation for
      the non-inplace code. Closes ticket 18258. Patch from Malek.
    - Simplify return types for some crypto functions that can't
      actually fail. Patch from Hassan Alsibyani. Closes ticket 18259.

  o Documentation:
    - Change build messages to refer to "Fedora" instead of "Fedora
      Core", and "dnf" instead of "yum". Closes tickets 18459 and 18426.
      Patches from "icanhasaccount" and "cypherpunks".

  o Removed features:
    - We no longer maintain an internal freelist in memarea.c.
      Allocators should be good enough to make this code unnecessary,
      and it's doubtful that it ever had any performance benefit.

  o Testing:
    - Fix several warnings from clang's address sanitizer produced in
      the unit tests.
    - Treat backtrace test failures as expected on FreeBSD until we
      solve bug 17808. Closes ticket 18204.


Changes in version 0.2.8.1-alpha - 2016-02-04
  Tor 0.2.8.1-alpha is the first alpha release in its series. It
  includes numerous small features and bugfixes against previous Tor
  versions, and numerous small infrastructure improvements. The most
  notable features are a set of improvements to the directory subsystem.

  o Major features (security, Linux):
    - When Tor starts as root on Linux and is told to switch user ID, it
      can now retain the capability to bind to low ports. By default,
      Tor will do this only when it's switching user ID and some low
      ports have been configured. You can change this behavior with the
      new option KeepBindCapabilities. Closes ticket 8195.

  o Major features (directory system):
    - When bootstrapping multiple consensus downloads at a time, use the
      first one that starts downloading, and close the rest. This
      reduces failures when authorities or fallback directories are slow
      or down. Together with the code for feature 15775, this feature
      should reduces failures due to fallback churn. Implements ticket
      4483. Patch by "teor". Implements IPv4 portions of proposal 210 by
      "mikeperry" and "teor".
    - Include a trial list of 21 default fallback directories, generated
      in January 2016, based on an opt-in survey of suitable relays.
      Doing this should make clients bootstrap more quickly and reliably,
      and reduce the load on the directory authorities. Closes ticket
      15775. Patch by "teor".
      Candidates identified using an OnionOO script by "weasel", "teor",
      "gsathya", and "karsten".
    - Previously only relays that explicitly opened a directory port
      (DirPort) accepted directory requests from clients. Now all
      relays, with and without a DirPort, accept and serve tunneled
      directory requests that they receive through their ORPort. You can
      disable this behavior using the new DirCache option. Closes
      ticket 12538.

  o Major key updates:
    - Update the V3 identity key for the dannenberg directory authority:
      it was changed on 18 November 2015. Closes task 17906. Patch
      by "teor".

  o Minor features (security, clock):
    - Warn when the system clock appears to move back in time (when the
      state file was last written in the future). Tor doesn't know that
      consensuses have expired if the clock is in the past. Patch by
      "teor". Implements ticket 17188.

  o Minor features (security, exit policies):
    - ExitPolicyRejectPrivate now rejects more private addresses by
      default. Specifically, it now rejects the relay's outbound bind
      addresses (if configured), and the relay's configured port
      addresses (such as ORPort and DirPort). Fixes bug 17027; bugfix on
      0.2.0.11-alpha. Patch by "teor".

  o Minor features (security, memory erasure):
    - Set the unused entries in a smartlist to NULL. This helped catch
      a (harmless) bug, and shouldn't affect performance too much.
      Implements ticket 17026.
    - Use SecureMemoryWipe() function to securely clean memory on
      Windows. Previously we'd use OpenSSL's OPENSSL_cleanse() function.
      Implements feature 17986.
    - Use explicit_bzero or memset_s when present. Previously, we'd use
      OpenSSL's OPENSSL_cleanse() function. Closes ticket 7419; patches
      from <logan@hackers.mu> and <selven@hackers.mu>.
    - Make memwipe() do nothing when passed a NULL pointer or buffer of
      zero size. Check size argument to memwipe() for underflow. Fixes
      bug 18089; bugfix on 0.2.3.25 and 0.2.4.6-alpha. Reported by "gk",
      patch by "teor".

  o Minor features (security, RNG):
    - Adjust Tor's use of OpenSSL's RNG APIs so that they absolutely,
      positively are not allowed to fail. Previously we depended on
      internal details of OpenSSL's behavior. Closes ticket 17686.
    - Never use the system entropy output directly for anything besides
      seeding the PRNG. When we want to generate important keys, instead
      of using system entropy directly, we now hash it with the PRNG
      stream. This may help resist certain attacks based on broken OS
      entropy implementations. Closes part of ticket 17694.
    - Use modern system calls (like getentropy() or getrandom()) to
      generate strong entropy on platforms that have them. Closes
      ticket 13696.

  o Minor features (accounting):
    - Added two modes to the AccountingRule option: One for limiting
      only the number of bytes sent ("AccountingRule out"), and one for
      limiting only the number of bytes received ("AccountingRule in").
      Closes ticket 15989; patch from "unixninja92".

  o Minor features (build):
    - Since our build process now uses "make distcheck", we no longer
      force "make dist" to depend on "make check". Closes ticket 17893;
      patch from "cypherpunks."
    - Tor now builds successfully with the recent OpenSSL 1.1
      development branch, and with the latest LibreSSL. Closes tickets
      17549, 17921, and 17984.

  o Minor features (controller):
    - Adds the FallbackDir entries to 'GETINFO config/defaults'. Closes
      tickets 16774 and 17817. Patch by George Tankersley.
    - New 'GETINFO hs/service/desc/id/' command to retrieve a hidden
      service descriptor from a service's local hidden service
      descriptor cache. Closes ticket 14846.
    - Add 'GETINFO exit-policy/reject-private/[default,relay]', so
      controllers can examine the the reject rules added by
      ExitPolicyRejectPrivate. This makes it easier for stem to display
      exit policies.

  o Minor features (crypto):
    - Add SHA512 support to crypto.c. Closes ticket 17663; patch from
      George Tankersley.
    - Add SHA3 and SHAKE support to crypto.c. Closes ticket 17783.
    - When allocating a digest state object, allocate no more space than
      we actually need. Previously, we would allocate as much space as
      the state for the largest algorithm would need. This change saves
      up to 672 bytes per circuit. Closes ticket 17796.
    - Improve performance when hashing non-multiple of 8 sized buffers,
      based on Andrew Moon's public domain SipHash-2-4 implementation.
      Fixes bug 17544; bugfix on 0.2.5.3-alpha.

  o Minor features (directory downloads):
    - Wait for busy authorities and fallback directories to become non-
      busy when bootstrapping. (A similar change was made in 6c443e987d
      for directory caches chosen from the consensus.) Closes ticket
      17864; patch by "teor".
    - Add UseDefaultFallbackDirs, which enables any hard-coded fallback
      directory mirrors. The default is 1; set it to 0 to disable
      fallbacks. Implements ticket 17576. Patch by "teor".

  o Minor features (geoip):
    - Update geoip and geoip6 to the January 5 2016 Maxmind GeoLite2
      Country database.

  o Minor features (IPv6):
    - Add an argument 'ipv6=address:orport' to the DirAuthority and
      FallbackDir torrc options, to specify an IPv6 address for an
      authority or fallback directory. Add hard-coded ipv6 addresses for
      directory authorities that have them. Closes ticket 17327; patch
      from Nick Mathewson and "teor".
    - Add address policy assume_action support for IPv6 addresses.
    - Limit IPv6 mask bits to 128.
    - Warn when comparing against an AF_UNSPEC address in a policy, it's
      almost always a bug. Closes ticket 17863; patch by "teor".
    - Allow users to configure directory authorities and fallback
      directory servers with IPv6 addresses and ORPorts. Resolves
      ticket 6027.
    - routerset_parse now accepts IPv6 literal addresses. Fixes bug
      17060; bugfix on 0.2.1.3-alpha. Patch by "teor".
    - Make tor_ersatz_socketpair work on IPv6-only systems. Fixes bug
      17638; bugfix on 0.0.2pre8. Patch by "teor".

  o Minor features (logging):
    - When logging to syslog, allow a tag to be added to the syslog
      identity (the string prepended to every log message). The tag can
      be configured with SyslogIdentityTag and defaults to none. Setting
      it to "foo" will cause logs to be tagged as "Tor-foo". Closes
      ticket 17194.

  o Minor features (portability):
    - Use timingsafe_memcmp() where available. Closes ticket 17944;
      patch from <logan@hackers.mu>.

  o Minor features (relay, address discovery):
    - Add a family argument to get_interface_addresses_raw() and
      subfunctions to make network interface address interogation more
      efficient. Now Tor can specifically ask for IPv4, IPv6 or both
      types of interfaces from the operating system. Resolves
      ticket 17950.
    - When get_interface_address6_list(.,AF_UNSPEC,.) is called and
      fails to enumerate interface addresses using the platform-specific
      API, have it rely on the UDP socket fallback technique to try and
      find out what IP addresses (both IPv4 and IPv6) our machine has.
      Resolves ticket 17951.

  o Minor features (replay cache):
    - The replay cache now uses SHA256 instead of SHA1. Implements
      feature 8961. Patch by "teor", issue reported by "rransom".

  o Minor features (unix file permissions):
    - Defer creation of Unix sockets until after setuid. This avoids
      needing CAP_CHOWN and CAP_FOWNER when using systemd's
      CapabilityBoundingSet, or chown and fowner when using SELinux.
      Implements part of ticket 17562. Patch from Jamie Nguyen.
    - If any directory created by Tor is marked as group readable, the
      filesystem group is allowed to be either the default GID or the
      root user. Allowing root to read the DataDirectory prevents the
      need for CAP_READ_SEARCH when using systemd's
      CapabilityBoundingSet, or dac_read_search when using SELinux.
      Implements part of ticket 17562. Patch from Jamie Nguyen.
    - Introduce a new DataDirectoryGroupReadable option. If it is set to
      1, the DataDirectory will be made readable by the default GID.
      Implements part of ticket 17562. Patch from Jamie Nguyen.

  o Minor bugfixes (accounting):
    - The max bandwidth when using 'AccountRule sum' is now correctly
      logged. Fixes bug 18024; bugfix on 0.2.6.1-alpha. Patch
      from "unixninja92".

  o Minor bugfixes (code correctness):
    - When closing an entry connection, generate a warning if we should
      have sent an end cell for it but we haven't. Fixes bug 17876;
      bugfix on 0.2.3.2-alpha.
    - Assert that allocated memory held by the reputation code is freed
      according to its internal counters. Fixes bug 17753; bugfix
      on 0.1.1.1-alpha.
    - Assert when the TLS contexts fail to initialize. Fixes bug 17683;
      bugfix on 0.0.6.

  o Minor bugfixes (compilation):
    - Mark all object files that include micro-revision.i as depending
      on it, so as to make parallel builds more reliable. Fixes bug
      17826; bugfix on 0.2.5.1-alpha.
    - Don't try to use the pthread_condattr_setclock() function unless
      it actually exists. Fixes compilation on NetBSD-6.x. Fixes bug
      17819; bugfix on 0.2.6.3-alpha.
    - Fix backtrace compilation on FreeBSD. Fixes bug 17827; bugfix
      on 0.2.5.2-alpha.
    - Fix compilation of sandbox.c with musl-libc. Fixes bug 17347;
      bugfix on 0.2.5.1-alpha. Patch from 'jamestk'.
    - Fix search for libevent libraries on OpenBSD (and other systems
      that install libevent 1 and libevent 2 in parallel). Fixes bug
      16651; bugfix on 0.1.0.7-rc. Patch from "rubiate".
    - Isolate environment variables meant for tests from the rest of the
      build system. Fixes bug 17818; bugfix on 0.2.7.3-rc.
    - Replace usage of 'INLINE' with 'inline'. Fixes bug 17804; bugfix
      on 0.0.2pre8.
    - Remove config.log only from make distclean, not from make clean.
      Fixes bug 17924; bugfix on 0.2.4.1-alpha.

  o Minor bugfixes (crypto):
    - Check the return value of HMAC() and assert on failure. Fixes bug
      17658; bugfix on 0.2.3.6-alpha. Patch by "teor".

  o Minor bugfixes (fallback directories):
    - Mark fallbacks as "too busy" when they return a 503 response,
      rather than just marking authorities. Fixes bug 17572; bugfix on
      0.2.4.7-alpha. Patch by "teor".

  o Minor bugfixes (IPv6):
    - Update the limits in max_dl_per_request for IPv6 address length.
      Fixes bug 17573; bugfix on 0.2.1.5-alpha.

  o Minor bugfixes (linux seccomp2 sandbox):
    - Fix a crash when using offline master ed25519 keys with the Linux
      seccomp2 sandbox enabled. Fixes bug 17675; bugfix on 0.2.7.3-rc.

  o Minor bugfixes (logging):
    - In log messages that include a function name, use __FUNCTION__
      instead of __PRETTY_FUNCTION__. In GCC, these are synonymous, but
      with clang __PRETTY_FUNCTION__ has extra information we don't
      need. Fixes bug 16563; bugfix on 0.0.2pre8. Fix by Tom van
      der Woerdt.
    - Remove needless quotes from a log message about unparseable
      addresses. Fixes bug 17843; bugfix on 0.2.3.3-alpha.

  o Minor bugfixes (portability):
    - Remove an #endif from configure.ac so that we correctly detect the
      presence of in6_addr.s6_addr32. Fixes bug 17923; bugfix
      on 0.2.0.13-alpha.

  o Minor bugfixes (relays):
    - Check that both the ORPort and DirPort (if present) are reachable
      before publishing a relay descriptor. Otherwise, relays publish a
      descriptor with DirPort 0 when the DirPort reachability test takes
      longer than the ORPort reachability test. Fixes bug 18050; bugfix
      on 0.1.0.1-rc. Reported by "starlight", patch by "teor".

  o Minor bugfixes (relays, hidden services):
    - Refuse connection requests to private OR addresses unless
      ExtendAllowPrivateAddresses is set. Previously, tor would connect,
      then refuse to send any cells to a private address. Fixes bugs
      17674 and 8976; bugfix on 0.2.3.21-rc. Patch by "teor".

  o Minor bugfixes (safe logging):
    - When logging a malformed hostname received through socks4, scrub
      it if SafeLogging says we should. Fixes bug 17419; bugfix
      on 0.1.1.16-rc.

  o Minor bugfixes (statistics code):
    - Consistently check for overflow in round_*_to_next_multiple_of
      functions, and add unit tests with additional and maximal values.
      Fixes part of bug 13192; bugfix on 0.2.2.1-alpha.
    - Handle edge cases in the laplace functions: avoid division by
      zero, avoid taking the log of zero, and silence clang type
      conversion warnings using round and trunc. Add unit tests for edge
      cases with maximal values. Fixes part of bug 13192; bugfix
      on 0.2.6.2-alpha.

  o Minor bugfixes (testing):
    - The test for log_heartbeat was incorrectly failing in timezones
      with non-integer offsets. Instead of comparing the end of the time
      string against a constant, compare it to the output of
      format_local_iso_time when given the correct input. Fixes bug
      18039; bugfix on 0.2.5.4-alpha.
    - Make unit tests pass on IPv6-only systems, and systems without
      localhost addresses (like some FreeBSD jails). Fixes bug 17632;
      bugfix on 0.2.7.3-rc. Patch by "teor".
    - Fix a memory leak in the ntor test. Fixes bug 17778; bugfix
      on 0.2.4.8-alpha.
    - Check the full results of SHA256 and SHA512 digests in the unit
      tests. Bugfix on 0.2.2.4-alpha. Patch by "teor".

  o Code simplification and refactoring:
    - Move logging of redundant policy entries in
      policies_parse_exit_policy_internal into its own function. Closes
      ticket 17608; patch from "juce".
    - Extract the more complicated parts of circuit_mark_for_close()
      into a new function that we run periodically before circuits are
      freed. This change removes more than half of the functions
      currently in the "blob". Closes ticket 17218.
    - Clean up a little duplicated code in
      crypto_expand_key_material_TAP(). Closes ticket 17587; patch
      from "pfrankw".
    - Decouple the list of streams waiting to be attached to circuits
      from the overall connection list. This change makes it possible to
      attach streams quickly while simplifying Tor's callgraph and
      avoiding O(N) scans of the entire connection list. Closes
      ticket 17590.
    - When a direct directory request fails immediately on launch,
      instead of relaunching that request from inside the code that
      launches it, instead mark the connection for teardown. This change
      simplifies Tor's callback and prevents the directory-request
      launching code from invoking itself recursively. Closes
      ticket 17589
    - Remove code for configuring OpenSSL dynamic locks; OpenSSL doesn't
      use them. Closes ticket 17926.

  o Documentation:
    - Add a description of the correct use of the '--keygen' command-
      line option. Closes ticket 17583; based on text by 's7r'.
    - Document the minimum HeartbeatPeriod value. Closes ticket 15638.
    - Explain actual minima for BandwidthRate. Closes ticket 16382.
    - Fix a minor formatting typo in the manpage. Closes ticket 17791.
    - Mention torspec URL in the manpage and point the reader to it
      whenever we mention a document that belongs in torspce. Fixes
      issue 17392.

  o Removed features:
    - Remove client-side support for connecting to Tor relays running
      versions of Tor before 0.2.3.6-alpha. These relays didn't support
      the v3 TLS handshake protocol, and are no longer allowed on the
      Tor network. Implements the client side of ticket 11150. Based on
      patches by Tom van der Woerdt.

  o Testing:
    - Add unit tests to check for common RNG failure modes, such as
      returning all zeroes, identical values, or incrementing values
      (OpenSSL's rand_predictable feature). Patch by "teor".
    - Log more information when the backtrace tests fail. Closes ticket
      17892. Patch from "cypherpunks."
    - Always test both ed25519 backends, so that we can be sure that our
      batch-open replacement code works. Part of ticket 16794.
    - Cover dns_resolve_impl() in dns.c with unit tests. Implements a
      portion of ticket 16831.
    - More unit tests for compat_libevent.c, procmon.c, tortls.c,
      util_format.c, directory.c, and options_validate.c. Closes tickets
      17075, 17082, 17084, 17003, and 17076 respectively. Patches from
      Ola Bini.
    - Unit tests for directory_handle_command_get. Closes ticket 17004.
      Patch from Reinaldo de Souza Jr.


Changes in version 0.2.7.6 - 2015-12-10
  Tor version 0.2.7.6 fixes a major bug in entry guard selection, as
  well as a minor bug in hidden service reliability.

  o Major bugfixes (guard selection):
    - Actually look at the Guard flag when selecting a new directory
      guard. When we implemented the directory guard design, we
      accidentally started treating all relays as if they have the Guard
      flag during guard selection, leading to weaker anonymity and worse
      performance. Fixes bug 17772; bugfix on 0.2.4.8-alpha. Discovered
      by Mohsen Imani.

  o Minor features (geoip):
    - Update geoip and geoip6 to the December 1 2015 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation):
    - When checking for net/pfvar.h, include netinet/in.h if possible.
      This fixes transparent proxy detection on OpenBSD. Fixes bug
      17551; bugfix on 0.1.2.1-alpha. Patch from "rubiate".
    - Fix a compilation warning with Clang 3.6: Do not check the
      presence of an address which can never be NULL. Fixes bug 17781.

  o Minor bugfixes (correctness):
    - When displaying an IPv6 exit policy, include the mask bits
      correctly even when the number is greater than 31. Fixes bug
      16056; bugfix on 0.2.4.7-alpha. Patch from "gturner".
    - The wrong list was used when looking up expired intro points in a
      rend service object, causing what we think could be reachability
      issues for hidden services, and triggering a BUG log. Fixes bug
      16702; bugfix on 0.2.7.2-alpha.
    - Fix undefined behavior in the tor_cert_checksig function. Fixes
      bug 17722; bugfix on 0.2.7.2-alpha.


Changes in version 0.2.7.5 - 2015-11-20
  The Tor 0.2.7 release series is dedicated to the memory of Tor user
  and privacy advocate Caspar Bowden (1961-2015). Caspar worked
  tirelessly to advocate human rights regardless of national borders,
  and oppose the encroachments of mass surveillance. He opposed national
  exceptionalism, he brought clarity to legal and policy debates, he
  understood and predicted the impact of mass surveillance on the world,
  and he laid the groundwork for resisting it. While serving on the Tor
  Project's board of directors, he brought us his uncompromising focus
  on technical excellence in the service of humankind. Caspar was an
  inimitable force for good and a wonderful friend. He was kind,
  humorous, generous, gallant, and believed we should protect one
  another without exception. We honor him here for his ideals, his
  efforts, and his accomplishments. Please honor his memory with works
  that would make him proud.

  Tor 0.2.7.5 is the first stable release in the Tor 0.2.7 series.

  The 0.2.7 series adds a more secure identity key type for relays,
  improves cryptography performance, resolves several longstanding
  hidden-service performance issues, improves controller support for
  hidden services, and includes small bugfixes and performance
  improvements throughout the program. This release series also includes
  more tests than before, and significant simplifications to which parts
  of Tor invoke which others.

  (This release contains no code changes since 0.2.7.4-rc.)


Changes in version 0.2.7.4-rc - 2015-10-21
  Tor 0.2.7.4-rc is the second release candidate in the 0.2.7 series. It
  fixes some important memory leaks, and a scary-looking (but mostly
  harmless in practice) invalid-read bug. It also has a few small
  bugfixes, notably fixes for compilation and portability on different
  platforms. If no further significant bounds are found, the next
  release will the the official stable release.

  o Major bugfixes (security, correctness):
    - Fix an error that could cause us to read 4 bytes before the
      beginning of an openssl string. This bug could be used to cause
      Tor to crash on systems with unusual malloc implementations, or
      systems with unusual hardening installed. Fixes bug 17404; bugfix
      on 0.2.3.6-alpha.

  o Major bugfixes (correctness):
    - Fix a use-after-free bug in validate_intro_point_failure(). Fixes
      bug 17401; bugfix on 0.2.7.3-rc.

  o Major bugfixes (memory leaks):
    - Fix a memory leak in ed25519 batch signature checking. Fixes bug
      17398; bugfix on 0.2.6.1-alpha.
    - Fix a memory leak in rend_cache_failure_entry_free(). Fixes bug
      17402; bugfix on 0.2.7.3-rc.
    - Fix a memory leak when reading an expired signing key from disk.
      Fixes bug 17403; bugfix on 0.2.7.2-rc.

  o Minor features (geoIP):
    - Update geoip and geoip6 to the October 9 2015 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (compilation):
    - Repair compilation with the most recent (unreleased, alpha)
      vesions of OpenSSL 1.1. Fixes part of ticket 17237.
    - Fix an integer overflow warning in test_crypto_slow.c. Fixes bug
      17251; bugfix on 0.2.7.2-alpha.
    - Fix compilation of sandbox.c with musl-libc. Fixes bug 17347;
      bugfix on 0.2.5.1-alpha. Patch from 'jamestk'.

  o Minor bugfixes (portability):
    - Use libexecinfo on FreeBSD to enable backtrace support. Fixes
      part of bug 17151; bugfix on 0.2.5.2-alpha. Patch from
      Marcin Cieślak.

  o Minor bugfixes (sandbox):
    - Add the "hidserv-stats" filename to our sandbox filter for the
      HiddenServiceStatistics option to work properly. Fixes bug 17354;
      bugfix on 0.2.6.2-alpha. Patch from David Goulet.

  o Minor bugfixes (testing):
    - Add unit tests for get_interface_address* failure cases. Fixes bug
      17173; bugfix on 0.2.7.3-rc. Patch by fk/teor.
    - Fix breakage when running 'make check' with BSD make. Fixes bug
      17154; bugfix on 0.2.7.3-rc. Patch by Marcin Cieślak.
    - Make the get_ifaddrs_* unit tests more tolerant of different
      network configurations. (Don't assume every test box has an IPv4
      address, and don't assume every test box has a non-localhost
      address.) Fixes bug 17255; bugfix on 0.2.7.3-rc. Patch by "teor".
    - Skip backtrace tests when backtrace support is not compiled in.
      Fixes part of bug 17151; bugfix on 0.2.7.1-alpha. Patch from
      Marcin Cieślak.

  o Documentation:
    - Fix capitalization of SOCKS in sample torrc. Closes ticket 15609.
    - Note that HiddenServicePorts can take a unix domain socket. Closes
      ticket 17364.


Changes in version 0.2.7.3-rc - 2015-09-25
  Tor 0.2.7.3-rc is the first release candidate in the 0.2.7 series. It
  contains numerous usability fixes for Ed25519 keys, safeguards against
  several misconfiguration problems, significant simplifications to
  Tor's callgraph, and numerous bugfixes and small features.

  This is the most tested release of Tor to date. The unit tests cover
  39.40% of the code, and the integration tests (accessible with "make
  test-full-online", requiring stem and chutney and a network
  connection) raise the coverage to 64.49%.

  o Major features (security, hidden services):
    - Hidden services, if using the EntryNodes option, are required to
      use more than one EntryNode, in order to avoid a guard discovery
      attack. (This would only affect people who had configured hidden
      services and manually specified the EntryNodes option with a
      single entry-node. The impact was that it would be easy to
      remotely identify the guard node used by such a hidden service.
      See ticket for more information.) Fixes ticket 14917.

  o Major features (Ed25519 keys, keypinning):
    - The key-pinning option on directory authorities is now advisory-
      only by default. In a future version, or when the AuthDirPinKeys
      option is set, pins are enforced again. Disabling key-pinning
      seemed like a good idea so that we can survive the fallout of any
      usability problems associated with Ed25519 keys. Closes
      ticket 17135.

  o Major features (Ed25519 performance):
    - Improve the speed of Ed25519 operations and Curve25519 keypair
      generation when built targeting 32 bit x86 platforms with SSE2
      available. Implements ticket 16535.
    - Improve the runtime speed of Ed25519 signature verification by
      using Ed25519-donna's batch verification support. Implements
      ticket 16533.

  o Major features (performance testing):
    - The test-network.sh script now supports performance testing.
      Requires corresponding chutney performance testing changes. Patch
      by "teor". Closes ticket 14175.

  o Major features (relay, Ed25519):
    - Significant usability improvements for Ed25519 key management. Log
      messages are better, and the code can recover from far more
      failure conditions. Thanks to "s7r" for reporting and diagnosing
      so many of these!
    - Add a new OfflineMasterKey option to tell Tor never to try loading
      or generating a secret Ed25519 identity key. You can use this in
      combination with tor --keygen to manage offline and/or encrypted
      Ed25519 keys. Implements ticket 16944.
    - Add a --newpass option to allow changing or removing the
      passphrase of an encrypted key with tor --keygen. Implements part
      of ticket 16769.
    - On receiving a HUP signal, check to see whether the Ed25519
      signing key has changed, and reload it if so. Closes ticket 16790.

  o Major bugfixes (relay, Ed25519):
    - Avoid crashing on 'tor --keygen'. Fixes bug 16679; bugfix on
      0.2.7.2-alpha. Reported by "s7r".
    - Improve handling of expired signing keys with offline master keys.
      Fixes bug 16685; bugfix on 0.2.7.2-alpha. Reported by "s7r".

  o Minor features (client-side privacy):
    - New KeepAliveIsolateSOCKSAuth option to indefinitely extend circuit
      lifespan when IsolateSOCKSAuth and streams with SOCKS
      authentication are attached to the circuit. This allows
      applications like TorBrowser to manage circuit lifetime on their
      own. Implements feature 15482.
    - When logging malformed hostnames from SOCKS5 requests, respect
      SafeLogging configuration. Fixes bug 16891; bugfix on 0.1.1.16-rc.

  o Minor features (compilation):
    - Give a warning as early as possible when trying to build with an
      unsupported OpenSSL version. Closes ticket 16901.
    - Fail during configure if we're trying to build against an OpenSSL
      built without ECC support. Fixes bug 17109, bugfix on 0.2.7.1-alpha
      which started requiring ECC.

  o Minor features (geoip):
    - Update geoip and geoip6 to the September 3 2015 Maxmind GeoLite2
      Country database.

  o Minor features (hidden services):
    - Relays need to have the Fast flag to get the HSDir flag. As this
      is being written, we'll go from 2745 HSDirs down to 2342, a ~14%
      drop. This change should make some attacks against the hidden
      service directory system harder. Fixes ticket 15963.
    - Turn on hidden service statistics collection by setting the torrc
      option HiddenServiceStatistics to "1" by default. (This keeps
      track only of the fraction of traffic used by hidden services, and
      the total number of hidden services in existence.) Closes
      ticket 15254.
    - Client now uses an introduction point failure cache to know when
      to fetch or keep a descriptor in their cache. Previously, failures
      were recorded implicitly, but not explicitly remembered. Closes
      ticket 16389.

  o Minor features (testing, authorities, documentation):
    - New TestingDirAuthVote{Exit,Guard,HSDir}IsStrict flags to
      explicitly manage consensus flags in testing networks. Patch by
      "robgjansen", modified by "teor". Implements part of ticket 14882.

  o Minor bugfixes (security, exit policies):
    - ExitPolicyRejectPrivate now also rejects the relay's published
      IPv6 address (if any), and any publicly routable IPv4 or IPv6
      addresses on any local interfaces. ticket 17027. Patch by "teor".
      Fixes bug 17027; bugfix on 0.2.0.11-alpha.

  o Minor bug fixes (torrc exit policies):
    - In torrc, "accept6 *" and "reject6 *" ExitPolicy lines now only
      produce IPv6 wildcard addresses. Previously they would produce
      both IPv4 and IPv6 wildcard addresses. Patch by "teor". Fixes part
      of bug 16069; bugfix on 0.2.4.7-alpha.
    - When parsing torrc ExitPolicies, we now warn for a number of cases
      where the user's intent is likely to differ from Tor's actual
      behavior. These include: using an IPv4 address with an accept6 or
      reject6 line; using "private" on an accept6 or reject6 line; and
      including any ExitPolicy lines after accept *:* or reject *:*.
      Related to ticket 16069.
    - When parsing torrc ExitPolicies, we now issue an info-level
      message when expanding an "accept/reject *" line to include both
      IPv4 and IPv6 wildcard addresses. Related to ticket 16069.
    - In each instance above, usage advice is provided to avoid the
      message. Resolves ticket 16069. Patch by "teor". Fixes part of bug
      16069; bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (authority):
    - Don't assign "HSDir" to a router if it isn't Valid and Running.
      Fixes bug 16524; bugfix on 0.2.7.2-alpha.
    - Downgrade log messages about Ed25519 key issues if they are in old
      cached router descriptors. Fixes part of bug 16286; bugfix
      on 0.2.7.2-alpha.
    - When we find an Ed25519 key issue in a cached descriptor, stop
      saying the descriptor was just "uploaded". Fixes another part of
      bug 16286; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (control port):
    - Repair a warning and a spurious result when getting the maximum
      number of file descriptors from the controller. Fixes bug 16697;
      bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (correctness):
    - When calling channel_free_list(), avoid calling smartlist_remove()
      while inside a FOREACH loop. This partially reverts commit
      17356fe7fd96af where the correct SMARTLIST_DEL_CURRENT was
      incorrectly removed. Fixes bug 16924; bugfix on 0.2.4.4-alpha.

  o Minor bugfixes (documentation):
    - Advise users on how to configure separate IPv4 and IPv6 exit
      policies in the manpage and sample torrcs. Related to ticket 16069.
    - Fix the usage message of tor-resolve(1) so that it no longer lists
      the removed -F option. Fixes bug 16913; bugfix on 0.2.2.28-beta.
    - Fix an error in the manual page and comments for
      TestingDirAuthVoteHSDir[IsStrict], which suggested that a HSDir
      required "ORPort connectivity". While this is true, it is in no
      way unique to the HSDir flag. Of all the flags, only HSDirs need a
      DirPort configured in order for the authorities to assign that
      particular flag. Patch by "teor". Fixed as part of 14882; bugfix
      on 0.2.6.3-alpha.

  o Minor bugfixes (Ed25519):
    - Fix a memory leak when reading router descriptors with expired
      Ed25519 certificates. Fixes bug 16539; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (linux seccomp2 sandbox):
    - Allow bridge authorities to run correctly under the seccomp2
      sandbox. Fixes bug 16964; bugfix on 0.2.5.1-alpha.
    - Allow routers with ed25519 keys to run correctly under the
      seccomp2 sandbox. Fixes bug 16965; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (open file limit):
    - Fix set_max_file_descriptors() to set by default the max open file
      limit to the current limit when setrlimit() fails. Fixes bug
      16274; bugfix on 0.2.0.10-alpha. Patch by dgoulet.

  o Minor bugfixes (portability):
    - Try harder to normalize the exit status of the Tor process to the
      standard-provided range. Fixes bug 16975; bugfix on every version
      of Tor ever.
    - Check correctly for Windows socket errors in the workqueue
      backend. Fixes bug 16741; bugfix on 0.2.6.3-alpha.
    - Fix the behavior of crypto_rand_time_range() when told to consider
      times before 1970. (These times were possible when running in a
      simulated network environment where time()'s output starts at
      zero.) Fixes bug 16980; bugfix on 0.2.7.1-alpha.
    - Restore correct operation of TLS client-cipher detection on
      OpenSSL 1.1. Fixes bug 14047; bugfix on 0.2.7.2-alpha.

  o Minor bugfixes (relay):
    - Ensure that worker threads actually exit when a fatal error or
      shutdown is indicated. This fix doesn't currently affect the
      behavior of Tor, because Tor workers never indicates fatal error
      or shutdown except in the unit tests. Fixes bug 16868; bugfix
      on 0.2.6.3-alpha.
    - Unblock threads before releasing the work queue mutex to ensure
      predictable scheduling behavior. Fixes bug 16644; bugfix
      on 0.2.6.3-alpha.

  o Code simplification and refactoring:
    - Change the function that's called when we need to retry all
      downloads so that it only reschedules the downloads to happen
      immediately, rather than launching them all at once itself. This
      further simplifies Tor's callgraph.
    - Move some format-parsing functions out of crypto.c and
      crypto_curve25519.c into crypto_format.c and/or util_format.c.
    - Move the client-only parts of init_keys() into a separate
      function. Closes ticket 16763.
    - Simplify the microdesc_free() implementation so that it no longer
      appears (to code analysis tools) to potentially invoke a huge
      suite of other microdesc functions.
    - Simply the control graph further by deferring the inner body of
      directory_all_unreachable() into a callback. Closes ticket 16762.
    - Treat the loss of an owning controller as equivalent to a SIGTERM
      signal. This removes a tiny amount of duplicated code, and
      simplifies our callgraph. Closes ticket 16788.
    - When generating an event to send to the controller, we no longer
      put the event over the network immediately. Instead, we queue
      these events, and use a Libevent callback to deliver them. This
      change simplifies Tor's callgraph by reducing the number of
      functions from which all other Tor functions are reachable. Closes
      ticket 16695.
    - Wrap Windows-only C files inside '#ifdef _WIN32' so that tools
      that try to scan or compile every file on Unix won't decide that
      they are broken.
    - Remove the unused "nulterminate" argument from buf_pullup().

  o Documentation:
    - Recommend a 40 GB example AccountingMax in torrc.sample rather
      than a 4 GB max. Closes ticket 16742.
    - Include the TUNING document in our source tarball. It is referred
      to in the ChangeLog and an error message. Fixes bug 16929; bugfix
      on 0.2.6.1-alpha.

  o Removed code:
    - The internal pure-C tor-fw-helper tool is now removed from the Tor
      distribution, in favor of the pure-Go clone available from
      https://gitweb.torproject.org/tor-fw-helper.git/ . The libraries
      used by the C tor-fw-helper are not, in our opinion, very
      confidence- inspiring in their secure-programming techniques.
      Closes ticket 13338.
    - Remove the code that would try to aggressively flush controller
      connections while writing to them. This code was introduced in
      0.1.2.7-alpha, in order to keep output buffers from exceeding
      their limits. But there is no longer a maximum output buffer size,
      and flushing data in this way caused some undesirable recursions
      in our call graph. Closes ticket 16480.

  o Testing:
    - Make "bridges+hs" the default test network. This tests almost all
      tor functionality during make test-network, while allowing tests
      to succeed on non-IPv6 systems. Requires chutney commit 396da92 in
      test-network-bridges-hs. Closes tickets 16945 (tor) and 16946
      (chutney). Patches by "teor".
    - Autodetect CHUTNEY_PATH if the chutney and Tor sources are side-
      by-side in the same parent directory. Closes ticket 16903. Patch
      by "teor".
    - Use environment variables rather than autoconf substitutions to
      send variables from the build system to the test scripts. This
      change should be easier to maintain, and cause 'make distcheck' to
      work better than before. Fixes bug 17148.
    - Add a new set of callgraph analysis scripts that use clang to
      produce a list of which Tor functions are reachable from which
      other Tor functions. We're planning to use these to help simplify
      our code structure by identifying illogical dependencies.
    - Add new 'test-full' and 'test-full-online' targets to run all
      tests, including integration tests with stem and chutney.
    - Make the test-workqueue test work on Windows by initializing the
      network before we begin.
    - New make target (make test-network-all) to run multiple applicable
      chutney test cases. Patch from Teor; closes 16953.
    - Unit test dns_resolve(), dns_clip_ttl() and dns_get_expiry_ttl()
      functions in dns.c. Implements a portion of ticket 16831.
    - When building Tor with testing coverage enabled, run Chutney tests
      (if any) using the 'tor-cov' coverage binary.
    - When running test-network or test-stem, check for the absence of
      stem/chutney before doing any build operations.


Changes in version 0.2.7.2-alpha - 2015-07-27
  This, the second alpha in the Tor 0.2.7 series, has a number of new
  features, including a way to manually pick the number of introduction
  points for hidden services, and the much stronger Ed25519 signing key
  algorithm for regular Tor relays (including support for encrypted
  offline identity keys in the new algorithm).

  Support for Ed25519 on relays is currently limited to signing router
  descriptors; later alphas in this series will extend Ed25519 key
  support to more parts of the Tor protocol.

  o Major features (Ed25519 identity keys, Proposal 220):
    - All relays now maintain a stronger identity key, using the Ed25519
      elliptic curve signature format. This master key is designed so
      that it can be kept offline. Relays also generate an online
      signing key, and a set of other Ed25519 keys and certificates.
      These are all automatically regenerated and rotated as needed.
      Implements part of ticket 12498.
    - Directory authorities now vote on Ed25519 identity keys along with
      RSA1024 keys. Implements part of ticket 12498.
    - Directory authorities track which Ed25519 identity keys have been
      used with which RSA1024 identity keys, and do not allow them to
      vary freely. Implements part of ticket 12498.
    - Microdescriptors now include Ed25519 identity keys. Implements
      part of ticket 12498.
    - Add support for offline encrypted Ed25519 master keys. To use this
      feature on your tor relay, run "tor --keygen" to make a new master
      key (or to make a new signing key if you already have a master
      key). Closes ticket 13642.

  o Major features (Hidden services):
    - Add the torrc option HiddenServiceNumIntroductionPoints, to
      specify a fixed number of introduction points. Its maximum value
      is 10 and default is 3. Using this option can increase a hidden
      service's reliability under load, at the cost of making it more
      visible that the hidden service is facing extra load. Closes
      ticket 4862.
    - Remove the adaptive algorithm for choosing the number of
      introduction points, which used to change the number of
      introduction points (poorly) depending on the number of
      connections the HS sees. Closes ticket 4862.

  o Major features (onion key cross-certification):
    - Relay descriptors now include signatures of their own identity
      keys, made using the TAP and ntor onion keys. These signatures
      allow relays to prove ownership of their own onion keys. Because
      of this change, microdescriptors will no longer need to include
      RSA identity keys. Implements proposal 228; closes ticket 12499.

  o Major features (performance):
    - Improve the runtime speed of Ed25519 operations by using the
      public-domain Ed25519-donna by Andrew M. ("floodyberry").
      Implements ticket 16467.
    - Improve the runtime speed of the ntor handshake by using an
      optimized curve25519 basepoint scalarmult implementation from the
      public-domain Ed25519-donna by Andrew M. ("floodyberry"), based on
      ideas by Adam Langley. Implements ticket 9663.

  o Major bugfixes (client-side privacy, also in 0.2.6.9):
    - Properly separate out each SOCKSPort when applying stream
      isolation. The error occurred because each port's session group
      was being overwritten by a default value when the listener
      connection was initialized. Fixes bug 16247; bugfix on
      0.2.6.3-alpha. Patch by "jojelino".

  o Major bugfixes (hidden service clients, stability, also in 0.2.6.10):
    - Stop refusing to store updated hidden service descriptors on a
      client. This reverts commit 9407040c59218 (which indeed fixed bug
      14219, but introduced a major hidden service reachability
      regression detailed in bug 16381). This is a temporary fix since
      we can live with the minor issue in bug 14219 (it just results in
      some load on the network) but the regression of 16381 is too much
      of a setback. First-round fix for bug 16381; bugfix
      on 0.2.6.3-alpha.

  o Major bugfixes (hidden services):
    - When cannibalizing a circuit for an introduction point, always
      extend to the chosen exit node (creating a 4 hop circuit).
      Previously Tor would use the current circuit exit node, which
      changed the original choice of introduction point, and could cause
      the hidden service to skip excluded introduction points or
      reconnect to a skipped introduction point. Fixes bug 16260; bugfix
      on 0.1.0.1-rc.

  o Major bugfixes (open file limit):
    - The open file limit wasn't checked before calling
      tor_accept_socket_nonblocking(), which would make Tor exceed the
      limit. Now, before opening a new socket, Tor validates the open
      file limit just before, and if the max has been reached, return an
      error. Fixes bug 16288; bugfix on 0.1.1.1-alpha.

  o Major bugfixes (stability, also in 0.2.6.10):
    - Stop crashing with an assertion failure when parsing certain kinds
      of malformed or truncated microdescriptors. Fixes bug 16400;
      bugfix on 0.2.6.1-alpha. Found by "torkeln"; fix based on a patch
      by "cypherpunks_backup".
    - Stop random client-side assertion failures that could occur when
      connecting to a busy hidden service, or connecting to a hidden
      service while a NEWNYM is in progress. Fixes bug 16013; bugfix
      on 0.1.0.1-rc.

  o Minor features (directory authorities, security, also in 0.2.6.9):
    - The HSDir flag given by authorities now requires the Stable flag.
      For the current network, this results in going from 2887 to 2806
      HSDirs. Also, it makes it harder for an attacker to launch a sybil
      attack by raising the effort for a relay to become Stable to
      require at the very least 7 days, while maintaining the 96 hours
      uptime requirement for HSDir. Implements ticket 8243.

  o Minor features (client):
    - Relax the validation of hostnames in SOCKS5 requests, allowing the
      character '_' to appear, in order to cope with domains observed in
      the wild that are serving non-RFC compliant records. Resolves
      ticket 16430.
    - Relax the validation done to hostnames in SOCKS5 requests, and
      allow a single trailing '.' to cope with clients that pass FQDNs
      using that syntax to explicitly indicate that the domain name is
      fully-qualified. Fixes bug 16674; bugfix on 0.2.6.2-alpha.
    - Add GroupWritable and WorldWritable options to unix-socket based
      SocksPort and ControlPort options. These options apply to a single
      socket, and override {Control,Socks}SocketsGroupWritable. Closes
      ticket 15220.

  o Minor features (control protocol):
    - Support network-liveness GETINFO key and NETWORK_LIVENESS event in
      the control protocol. Resolves ticket 15358.

  o Minor features (directory authorities):
    - Directory authorities no longer vote against the "Fast", "Stable",
      and "HSDir" flags just because they were going to vote against
      "Running": if the consensus turns out to be that the router was
      running, then the authority's vote should count. Patch from Peter
      Retzlaff; closes issue 8712.

  o Minor features (geoip, also in 0.2.6.10):
    - Update geoip to the June 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the June 3 2015 Maxmind GeoLite2 Country database.

  o Minor features (hidden services):
    - Add the new options "HiddenServiceMaxStreams" and
      "HiddenServiceMaxStreamsCloseCircuit" to allow hidden services to
      limit the maximum number of simultaneous streams per circuit, and
      optionally tear down the circuit when the limit is exceeded. Part
      of ticket 16052.

  o Minor features (portability):
    - Use C99 variadic macros when the compiler is not GCC. This avoids
      failing compilations on MSVC, and fixes a log-file-based race
      condition in our old workarounds. Original patch from Gisle Vanem.

  o Minor bugfixes (compilation, also in 0.2.6.9):
    - Build with --enable-systemd correctly when libsystemd is
      installed, but systemd is not. Fixes bug 16164; bugfix on
      0.2.6.3-alpha. Patch from Peter Palfrader.

  o Minor bugfixes (controller):
    - Add the descriptor ID in each HS_DESC control event. It was
      missing, but specified in control-spec.txt. Fixes bug 15881;
      bugfix on 0.2.5.2-alpha.

  o Minor bugfixes (crypto error-handling, also in 0.2.6.10):
    - Check for failures from crypto_early_init, and refuse to continue.
      A previous typo meant that we could keep going with an
      uninitialized crypto library, and would have OpenSSL initialize
      its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
      when implementing ticket 4900. Patch by "teor".

  o Minor bugfixes (hidden services):
    - Fix a crash when reloading configuration while at least one
      configured and one ephemeral hidden service exists. Fixes bug
      16060; bugfix on 0.2.7.1-alpha.
    - Avoid crashing with a double-free bug when we create an ephemeral
      hidden service but adding it fails for some reason. Fixes bug
      16228; bugfix on 0.2.7.1-alpha.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Use the sandbox in tor_open_cloexec whether or not O_CLOEXEC is
      defined. Patch by "teor". Fixes bug 16515; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (Linux seccomp2 sandbox, also in 0.2.6.10):
    - Allow pipe() and pipe2() syscalls in the seccomp2 sandbox: we need
      these when eventfd2() support is missing. Fixes bug 16363; bugfix
      on 0.2.6.3-alpha. Patch from "teor".

  o Minor bugfixes (Linux seccomp2 sandbox, also in 0.2.6.9):
    - Fix sandboxing to work when running as a relay, by allowing the
      renaming of secret_id_key, and allowing the eventfd2 and futex
      syscalls. Fixes bug 16244; bugfix on 0.2.6.1-alpha. Patch by
      Peter Palfrader.
    - Allow systemd connections to work with the Linux seccomp2 sandbox
      code. Fixes bug 16212; bugfix on 0.2.6.2-alpha. Patch by
      Peter Palfrader.

  o Minor bugfixes (relay):
    - Fix a rarely-encountered memory leak when failing to initialize
      the thread pool. Fixes bug 16631; bugfix on 0.2.6.3-alpha. Patch
      from "cypherpunks".

  o Minor bugfixes (systemd):
    - Fix an accidental formatting error that broke the systemd
      configuration file. Fixes bug 16152; bugfix on 0.2.7.1-alpha.
    - Tor's systemd unit file no longer contains extraneous spaces.
      These spaces would sometimes confuse tools like deb-systemd-
      helper. Fixes bug 16162; bugfix on 0.2.5.5-alpha.

  o Minor bugfixes (tests):
    - Use the configured Python executable when running test-stem-full.
      Fixes bug 16470; bugfix on 0.2.7.1-alpha.

  o Minor bugfixes (tests, also in 0.2.6.9):
    - Fix a crash in the unit tests when built with MSVC2013. Fixes bug
      16030; bugfix on 0.2.6.2-alpha. Patch from "NewEraCracker".

  o Minor bugfixes (threads, comments):
    - Always initialize return value in compute_desc_id in rendcommon.c
      Patch by "teor". Fixes part of bug 16115; bugfix on 0.2.7.1-alpha.
    - Check for NULL values in getinfo_helper_onions(). Patch by "teor".
      Fixes part of bug 16115; bugfix on 0.2.7.1-alpha.
    - Remove undefined directive-in-macro in test_util_writepid clang
      3.7 complains that using a preprocessor directive inside a macro
      invocation in test_util_writepid in test_util.c is undefined.
      Patch by "teor". Fixes part of bug 16115; bugfix on 0.2.7.1-alpha.

  o Code simplification and refactoring:
    - Define WINVER and _WIN32_WINNT centrally, in orconfig.h, in order
      to ensure they remain consistent and visible everywhere.
    - Remove some vestigial workarounds for the MSVC6 compiler. We
      haven't supported that in ages.
    - The link authentication code has been refactored for better
      testability and reliability. It now uses code generated with the
      "trunnel" binary encoding generator, to reduce the risk of bugs
      due to programmer error. Done as part of ticket 12498.

  o Documentation:
    - Include a specific and (hopefully) accurate documentation of the
      torrc file's meta-format in doc/torrc_format.txt. This is mainly
      of interest to people writing programs to parse or generate torrc
      files. This document is not a commitment to long-term
      compatibility; some aspects of the current format are a bit
      ridiculous. Closes ticket 2325.

  o Removed features:
    - Tor no longer supports copies of OpenSSL that are missing support
      for Elliptic Curve Cryptography. (We began using ECC when
      available in 0.2.4.8-alpha, for more safe and efficient key
      negotiation.) In particular, support for at least one of P256 or
      P224 is now required, with manual configuration needed if only
      P224 is available. Resolves ticket 16140.
    - Tor no longer supports versions of OpenSSL before 1.0. (If you are
      on an operating system that has not upgraded to OpenSSL 1.0 or
      later, and you compile Tor from source, you will need to install a
      more recent OpenSSL to link Tor against.) These versions of
      OpenSSL are still supported by the OpenSSL, but the numerous
      cryptographic improvements in later OpenSSL releases makes them a
      clear choice. Resolves ticket 16034.
    - Remove the HidServDirectoryV2 option. Now all relays offer to
      store hidden service descriptors. Related to 16543.
    - Remove the VoteOnHidServDirectoriesV2 option, since all
      authorities have long set it to 1. Closes ticket 16543.

  o Testing:
    - Document use of coverity, clang static analyzer, and clang dynamic
      undefined behavior and address sanitizers in doc/HACKING. Include
      detailed usage instructions in the blacklist. Patch by "teor".
      Closes ticket 15817.
    - The link authentication protocol code now has extensive tests.
    - The relay descriptor signature testing code now has
      extensive tests.
    - The test_workqueue program now runs faster, and is enabled by
      default as a part of "make check".
    - Now that OpenSSL has its own scrypt implementation, add an unit
      test that checks for interoperability between libscrypt_scrypt()
      and OpenSSL's EVP_PBE_scrypt() so that we could not use libscrypt
      and rely on EVP_PBE_scrypt() whenever possible. Resolves
      ticket 16189.


Changes in version 0.2.6.10 - 2015-07-12
  Tor version 0.2.6.10 fixes some significant stability and hidden
  service client bugs, bulletproofs the cryptography init process, and
  fixes a bug when using the sandbox code with some older versions of
  Linux. Everyone running an older version, especially an older version
  of 0.2.6, should upgrade.

  o Major bugfixes (hidden service clients, stability):
    - Stop refusing to store updated hidden service descriptors on a
      client. This reverts commit 9407040c59218 (which indeed fixed bug
      14219, but introduced a major hidden service reachability
      regression detailed in bug 16381). This is a temporary fix since
      we can live with the minor issue in bug 14219 (it just results in
      some load on the network) but the regression of 16381 is too much
      of a setback. First-round fix for bug 16381; bugfix
      on 0.2.6.3-alpha.

  o Major bugfixes (stability):
    - Stop crashing with an assertion failure when parsing certain kinds
      of malformed or truncated microdescriptors. Fixes bug 16400;
      bugfix on 0.2.6.1-alpha. Found by "torkeln"; fix based on a patch
      by "cypherpunks_backup".
    - Stop random client-side assertion failures that could occur when
      connecting to a busy hidden service, or connecting to a hidden
      service while a NEWNYM is in progress. Fixes bug 16013; bugfix
      on 0.1.0.1-rc.

  o Minor features (geoip):
    - Update geoip to the June 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the June 3 2015 Maxmind GeoLite2 Country database.

  o Minor bugfixes (crypto error-handling):
    - Check for failures from crypto_early_init, and refuse to continue.
      A previous typo meant that we could keep going with an
      uninitialized crypto library, and would have OpenSSL initialize
      its own PRNG. Fixes bug 16360; bugfix on 0.2.5.2-alpha, introduced
      when implementing ticket 4900. Patch by "teor".

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Allow pipe() and pipe2() syscalls in the seccomp2 sandbox: we need
      these when eventfd2() support is missing. Fixes bug 16363; bugfix
      on 0.2.6.3-alpha. Patch from "teor".


Changes in version 0.2.6.9 - 2015-06-11
  Tor 0.2.6.9 fixes a regression in the circuit isolation code, increases the
  requirements for receiving an HSDir flag, and addresses some other small
  bugs in the systemd and sandbox code. Clients using circuit isolation
  should upgrade; all directory authorities should upgrade.

  o Major bugfixes (client-side privacy):
    - Properly separate out each SOCKSPort when applying stream
      isolation. The error occurred because each port's session group was
      being overwritten by a default value when the listener connection
      was initialized. Fixes bug 16247; bugfix on 0.2.6.3-alpha. Patch
      by "jojelino".

  o Minor feature (directory authorities, security):
    - The HSDir flag given by authorities now requires the Stable flag.
      For the current network, this results in going from 2887 to 2806
      HSDirs. Also, it makes it harder for an attacker to launch a sybil
      attack by raising the effort for a relay to become Stable which
      takes at the very least 7 days to do so and by keeping the 96
      hours uptime requirement for HSDir. Implements ticket 8243.

  o Minor bugfixes (compilation):
    - Build with --enable-systemd correctly when libsystemd is
      installed, but systemd is not. Fixes bug 16164; bugfix on
      0.2.6.3-alpha. Patch from Peter Palfrader.

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Fix sandboxing to work when running as a relaymby renaming of
      secret_id_key, and allowing the eventfd2 and futex syscalls. Fixes
      bug 16244; bugfix on 0.2.6.1-alpha. Patch by Peter Palfrader.
    - Allow systemd connections to work with the Linux seccomp2 sandbox
      code. Fixes bug 16212; bugfix on 0.2.6.2-alpha. Patch by
      Peter Palfrader.

  o Minor bugfixes (tests):
    - Fix a crash in the unit tests when built with MSVC2013. Fixes bug
      16030; bugfix on 0.2.6.2-alpha. Patch from "NewEraCracker".


Changes in version 0.2.6.8 - 2015-05-21
  Tor 0.2.6.8 fixes a bit of dodgy code in parsing INTRODUCE2 cells, and
  fixes an authority-side bug in assigning the HSDir flag. All directory
  authorities should upgrade.

  o Major bugfixes (hidden services, backport from 0.2.7.1-alpha):
    - Revert commit that made directory authorities assign the HSDir
      flag to relay without a DirPort; this was bad because such relays
      can't handle BEGIN_DIR cells. Fixes bug 15850; bugfix
      on 0.2.6.3-alpha.

  o Minor bugfixes (hidden service, backport from 0.2.7.1-alpha):
    - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
      a client authorized hidden service. Fixes bug 15823; bugfix
      on 0.2.1.6-alpha.

  o Minor features (geoip):
    - Update geoip to the April 8 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the April 8 2015 Maxmind GeoLite2
      Country database.


Changes in version 0.2.7.1-alpha - 2015-05-12
  Tor 0.2.7.1-alpha is the first alpha release in its series. It
  includes numerous small features and bugfixes against previous Tor
  versions, and numerous small infrastructure improvements. The most
  notable features are several new ways for controllers to interact with
  the hidden services subsystem.

  o New system requirements:
    - Tor no longer includes workarounds to support Libevent versions
      before 1.3e. Libevent 2.0 or later is recommended. Closes
      ticket 15248.

  o Major features (controller):
    - Add the ADD_ONION and DEL_ONION commands that allow the creation
      and management of hidden services via the controller. Closes
      ticket 6411.
    - New "GETINFO onions/current" and "GETINFO onions/detached"
      commands to get information about hidden services created via the
      controller. Part of ticket 6411.
    - New HSFETCH command to launch a request for a hidden service
      descriptor. Closes ticket 14847.
    - New HSPOST command to upload a hidden service descriptor. Closes
      ticket 3523. Patch by "DonnchaC".

  o Major bugfixes (hidden services):
    - Revert commit that made directory authorities assign the HSDir
      flag to relay without a DirPort; this was bad because such relays
      can't handle BEGIN_DIR cells. Fixes bug 15850; bugfix
      on 0.2.6.3-alpha.

  o Minor features (clock-jump tolerance):
    - Recover better when our clock jumps back many hours, like might
      happen for Tails or Whonix users who start with a very wrong
      hardware clock, use Tor to discover a more accurate time, and then
      fix their clock. Resolves part of ticket 8766.

  o Minor features (command-line interface):
    - Make --hash-password imply --hush to prevent unnecessary noise.
      Closes ticket 15542. Patch from "cypherpunks".
    - Print a warning whenever we find a relative file path being used
      as torrc option. Resolves issue 14018.

  o Minor features (controller):
    - Add DirAuthority lines for default directory authorities to the
      output of the "GETINFO config/defaults" command if not already
      present. Implements ticket 14840.
    - Controllers can now use "GETINFO hs/client/desc/id/..." to
      retrieve items from the client's hidden service descriptor cache.
      Closes ticket 14845.
    - Implement a new controller command "GETINFO status/fresh-relay-
      descs" to fetch a descriptor/extrainfo pair that was generated on
      demand just for the controller's use. Implements ticket 14784.

  o Minor features (DoS-resistance):
    - Make it harder for attackers to overload hidden services with
      introductions, by blocking multiple introduction requests on the
      same circuit. Resolves ticket 15515.

  o Minor features (geoip):
    - Update geoip to the April 8 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the April 8 2015 Maxmind GeoLite2
      Country database.

  o Minor features (HS popularity countermeasure):
    - To avoid leaking HS popularity, don't cycle the introduction point
      when we've handled a fixed number of INTRODUCE2 cells but instead
      cycle it when a random number of introductions is reached, thus
      making it more difficult for an attacker to find out the amount of
      clients that have used the introduction point for a specific HS.
      Closes ticket 15745.

  o Minor features (logging):
    - Include the Tor version in all LD_BUG log messages, since people
      tend to cut and paste those into the bugtracker. Implements
      ticket 15026.

  o Minor features (pluggable transports):
    - When launching managed pluggable transports on Linux systems,
      attempt to have the kernel deliver a SIGTERM on tor exit if the
      pluggable transport process is still running. Resolves
      ticket 15471.
    - When launching managed pluggable transports, setup a valid open
      stdin in the child process that can be used to detect if tor has
      terminated. The "TOR_PT_EXIT_ON_STDIN_CLOSE" environment variable
      can be used by implementations to detect this new behavior.
      Resolves ticket 15435.

  o Minor features (testing):
    - Add a test to verify that the compiler does not eliminate our
      memwipe() implementation. Closes ticket 15377.
    - Add make rule `check-changes` to verify the format of changes
      files. Closes ticket 15180.
    - Add unit tests for control_event_is_interesting(). Add a compile-
      time check that the number of events doesn't exceed the capacity
      of control_event_t.event_mask. Closes ticket 15431, checks for
      bugs similar to 13085. Patch by "teor".
    - Command-line argument tests moved to Stem. Resolves ticket 14806.
    - Integrate the ntor, backtrace, and zero-length keys tests into the
      automake test suite. Closes ticket 15344.
    - Remove assertions during builds to determine Tor's test coverage.
      We don't want to trigger these even in assertions, so including
      them artificially makes our branch coverage look worse than it is.
      This patch provides the new test-stem-full and coverage-html-full
      configure options. Implements ticket 15400.

  o Minor bugfixes (build):
    - Improve out-of-tree builds by making non-standard rules work and
      clean up additional files and directories. Fixes bug 15053; bugfix
      on 0.2.7.0-alpha.

  o Minor bugfixes (command-line interface):
    - When "--quiet" is provided along with "--validate-config", do not
      write anything to stdout on success. Fixes bug 14994; bugfix
      on 0.2.3.3-alpha.
    - When complaining about bad arguments to "--dump-config", use
      stderr, not stdout.

  o Minor bugfixes (configuration, unit tests):
    - Only add the default fallback directories when the DirAuthorities,
      AlternateDirAuthority, and FallbackDir directory config options
      are set to their defaults. The default fallback directory list is
      currently empty, this fix will only change tor's behavior when it
      has default fallback directories. Includes unit tests for
      consider_adding_dir_servers(). Fixes bug 15642; bugfix on
      90f6071d8dc0 in 0.2.4.7-alpha. Patch by "teor".

  o Minor bugfixes (correctness):
    - For correctness, avoid modifying a constant string in
      handle_control_postdescriptor. Fixes bug 15546; bugfix
      on 0.1.1.16-rc.
    - Remove side-effects from tor_assert() calls. This was harmless,
      because we never disable assertions, but it is bad style and
      unnecessary. Fixes bug 15211; bugfix on 0.2.5.5, 0.2.2.36,
      and 0.2.0.10.

  o Minor bugfixes (hidden service):
    - Fix an out-of-bounds read when parsing invalid INTRODUCE2 cells on
      a client authorized hidden service. Fixes bug 15823; bugfix
      on 0.2.1.6-alpha.
    - Remove an extraneous newline character from the end of hidden
      service descriptors. Fixes bug 15296; bugfix on 0.2.0.10-alpha.

  o Minor bugfixes (interface):
    - Print usage information for --dump-config when it is used without
      an argument. Also, fix the error message to use different wording
      and add newline at the end. Fixes bug 15541; bugfix
      on 0.2.5.1-alpha.

  o Minor bugfixes (logs):
    - When building Tor under Clang, do not include an extra set of
      parentheses in log messages that include function names. Fixes bug
      15269; bugfix on every released version of Tor when compiled with
      recent enough Clang.

  o Minor bugfixes (network):
    - When attempting to use fallback technique for network interface
      lookup, disregard loopback and multicast addresses since they are
      unsuitable for public communications.

  o Minor bugfixes (statistics):
    - Disregard the ConnDirectionStatistics torrc options when Tor is
      not a relay since in that mode of operation no sensible data is
      being collected and because Tor might run into measurement hiccups
      when running as a client for some time, then becoming a relay.
      Fixes bug 15604; bugfix on 0.2.2.35.

  o Minor bugfixes (test networks):
    - When self-testing reachability, use ExtendAllowPrivateAddresses to
      determine if local/private addresses imply reachability. The
      previous fix used TestingTorNetwork, which implies
      ExtendAllowPrivateAddresses, but this excluded rare configurations
      where ExtendAllowPrivateAddresses is set but TestingTorNetwork is
      not. Fixes bug 15771; bugfix on 0.2.6.1-alpha. Patch by "teor",
      issue discovered by CJ Ess.

  o Minor bugfixes (testing):
    - Check for matching value in server response in ntor_ref.py. Fixes
      bug 15591; bugfix on 0.2.4.8-alpha. Reported and fixed
      by "joelanders".
    - Set the severity correctly when testing
      get_interface_addresses_ifaddrs() and
      get_interface_addresses_win32(), so that the tests fail gracefully
      instead of triggering an assertion. Fixes bug 15759; bugfix on
      0.2.6.3-alpha. Reported by Nicolas Derive.

  o Code simplification and refactoring:
    - Move the hacky fallback code out of get_interface_address6() into
      separate function and get it covered with unit-tests. Resolves
      ticket 14710.
    - Refactor hidden service client-side cache lookup to intelligently
      report its various failure cases, and disentangle failure cases
      involving a lack of introduction points. Closes ticket 14391.
    - Use our own Base64 encoder instead of OpenSSL's, to allow more
      control over the output. Part of ticket 15652.

  o Documentation:
    - Improve the descriptions of statistics-related torrc options in
      the manpage to describe rationale and possible uses cases. Fixes
      issue 15550.
    - Improve the layout and formatting of ./configure --help messages.
      Closes ticket 15024. Patch from "cypherpunks".
    - Standardize on the term "server descriptor" in the manual page.
      Previously, we had used "router descriptor", "server descriptor",
      and "relay descriptor" interchangeably. Part of ticket 14987.

  o Removed code:
    - Remove `USE_OPENSSL_BASE64` and the corresponding fallback code
      and always use the internal Base64 decoder. The internal decoder
      has been part of tor since 0.2.0.10-alpha, and no one should
      be using the OpenSSL one. Part of ticket 15652.
    - Remove the 'tor_strclear()' function; use memwipe() instead.
      Closes ticket 14922.

  o Removed features:
    - Remove the (seldom-used) DynamicDHGroups feature. For anti-
      fingerprinting we now recommend pluggable transports; for forward-
      secrecy in TLS, we now use the P-256 group. Closes ticket 13736.
    - Remove the undocumented "--digests" command-line option. It
      complicated our build process, caused subtle build issues on
      multiple platforms, and is now redundant since we started
      including git version identifiers. Closes ticket 14742.
    - Tor no longer contains checks for ancient directory cache versions
      that didn't know about microdescriptors.
    - Tor no longer contains workarounds for stat files generated by
      super-old versions of Tor that didn't choose guards sensibly.


Changes in version 0.2.4.27 - 2015-04-06
  Tor 0.2.4.27 backports two fixes from 0.2.6.7 for security issues that
  could be used by an attacker to crash hidden services, or crash clients
  visiting hidden services. Hidden services should upgrade as soon as
  possible; clients should upgrade whenever packages become available.

  This release also backports a simple improvement to make hidden
  services a bit less vulnerable to denial-of-service attacks.

  o Major bugfixes (security, hidden service):
    - Fix an issue that would allow a malicious client to trigger an
      assertion failure and halt a hidden service. Fixes bug 15600;
      bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
    - Fix a bug that could cause a client to crash with an assertion
      failure when parsing a malformed hidden service descriptor. Fixes
      bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".

  o Minor features (DoS-resistance, hidden service):
    - Introduction points no longer allow multiple INTRODUCE1 cells to
      arrive on the same circuit. This should make it more expensive for
      attackers to overwhelm hidden services with introductions.
      Resolves ticket 15515.


Changes in version 0.2.5.12 - 2015-04-06
  Tor 0.2.5.12 backports two fixes from 0.2.6.7 for security issues that
  could be used by an attacker to crash hidden services, or crash clients
  visiting hidden services. Hidden services should upgrade as soon as
  possible; clients should upgrade whenever packages become available.

  This release also backports a simple improvement to make hidden
  services a bit less vulnerable to denial-of-service attacks.

  o Major bugfixes (security, hidden service):
    - Fix an issue that would allow a malicious client to trigger an
      assertion failure and halt a hidden service. Fixes bug 15600;
      bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
    - Fix a bug that could cause a client to crash with an assertion
      failure when parsing a malformed hidden service descriptor. Fixes
      bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".

  o Minor features (DoS-resistance, hidden service):
    - Introduction points no longer allow multiple INTRODUCE1 cells to
      arrive on the same circuit. This should make it more expensive for
      attackers to overwhelm hidden services with introductions.
      Resolves ticket 15515.


Changes in version 0.2.6.7 - 2015-04-06
  Tor 0.2.6.7 fixes two security issues that could be used by an
  attacker to crash hidden services, or crash clients visiting hidden
  services. Hidden services should upgrade as soon as possible; clients
  should upgrade whenever packages become available.

  This release also contains two simple improvements to make hidden
  services a bit less vulnerable to denial-of-service attacks.

  o Major bugfixes (security, hidden service):
    - Fix an issue that would allow a malicious client to trigger an
      assertion failure and halt a hidden service. Fixes bug 15600;
      bugfix on 0.2.1.6-alpha. Reported by "disgleirio".
    - Fix a bug that could cause a client to crash with an assertion
      failure when parsing a malformed hidden service descriptor. Fixes
      bug 15601; bugfix on 0.2.1.5-alpha. Found by "DonnchaC".

  o Minor features (DoS-resistance, hidden service):
    - Introduction points no longer allow multiple INTRODUCE1 cells to
      arrive on the same circuit. This should make it more expensive for
      attackers to overwhelm hidden services with introductions.
      Resolves ticket 15515.
    - Decrease the amount of reattempts that a hidden service performs
      when its rendezvous circuits fail. This reduces the computational
      cost for running a hidden service under heavy load. Resolves
      ticket 11447.


Changes in version 0.2.6.6 - 2015-03-24
  Tor 0.2.6.6 is the first stable release in the 0.2.6 series.

  It adds numerous safety, security, correctness, and performance
  improvements. Client programs can be configured to use more kinds of
  sockets, AutomapHosts works better, the multithreading backend is
  improved, cell transmission is refactored, test coverage is much
  higher, more denial-of-service attacks are handled, guard selection is
  improved to handle long-term guards better, pluggable transports
  should work a bit better, and some annoying hidden service performance
  bugs should be addressed.

  o Minor bugfixes (portability):
    - Use the correct datatype in the SipHash-2-4 function to prevent
      compilers from assuming any sort of alignment. Fixes bug 15436;
      bugfix on 0.2.5.3-alpha.

Changes in version 0.2.6.5-rc - 2015-03-18
  Tor 0.2.6.5-rc is the second and (hopefully) last release candidate in
  the 0.2.6. It fixes a small number of bugs found in 0.2.6.4-rc.

  o Major bugfixes (client):
    - Avoid crashing when making certain configuration option changes on
      clients. Fixes bug 15245; bugfix on 0.2.6.3-alpha. Reported
      by "anonym".

  o Major bugfixes (pluggable transports):
    - Initialize the extended OR Port authentication cookie before
      launching pluggable transports. This prevents a race condition
      that occured when server-side pluggable transports would cache the
      authentication cookie before it has been (re)generated. Fixes bug
      15240; bugfix on 0.2.5.1-alpha.

  o Major bugfixes (portability):
    - Do not crash on startup when running on Solaris. Fixes a bug
      related to our fix for 9495; bugfix on 0.2.6.1-alpha. Reported
      by "ruebezahl".

  o Minor features (heartbeat):
    - On relays, report how many connections we negotiated using each
      version of the Tor link protocols. This information will let us
      know if removing support for very old versions of the Tor
      protocols is harming the network. Closes ticket 15212.

  o Code simplification and refactoring:
    - Refactor main loop to extract the 'loop' part. This makes it
      easier to run Tor under Shadow. Closes ticket 15176.


Changes in version 0.2.5.11 - 2015-03-17
  Tor 0.2.5.11 is the second stable release in the 0.2.5 series.

  It backports several bugfixes from the 0.2.6 branch, including a
  couple of medium-level security fixes for relays and exit nodes.
  It also updates the list of directory authorities.

  o Directory authority changes:
    - Remove turtles as a directory authority.
    - Add longclaw as a new (v3) directory authority. This implements
      ticket 13296. This keeps the directory authority count at 9.
    - The directory authority Faravahar has a new IP address. This
      closes ticket 14487.

  o Major bugfixes (crash, OSX, security):
    - Fix a remote denial-of-service opportunity caused by a bug in
      OSX's _strlcat_chk() function. Fixes bug 15205; bug first appeared
      in OSX 10.9.

  o Major bugfixes (relay, stability, possible security):
    - Fix a bug that could lead to a relay crashing with an assertion
      failure if a buffer of exactly the wrong layout was passed to
      buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
      0.2.0.10-alpha. Patch from 'cypherpunks'.
    - Do not assert if the 'data' pointer on a buffer is advanced to the
      very end of the buffer; log a BUG message instead. Only assert if
      it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.

  o Major bugfixes (exit node stability):
    - Fix an assertion failure that could occur under high DNS load.
      Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
      diagnosed and fixed by "cypherpunks".

  o Major bugfixes (Linux seccomp2 sandbox):
    - Upon receiving sighup with the seccomp2 sandbox enabled, do not
      crash during attempts to call wait4. Fixes bug 15088; bugfix on
      0.2.5.1-alpha. Patch from "sanic".

  o Minor features (controller):
    - New "GETINFO bw-event-cache" to get information about recent
      bandwidth events. Closes ticket 14128. Useful for controllers to
      get recent bandwidth history after the fix for ticket 13988.

  o Minor features (geoip):
    - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the March 3 2015 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (client, automapping):
    - Avoid crashing on torrc lines for VirtualAddrNetworkIPv[4|6] when
      no value follows the option. Fixes bug 14142; bugfix on
      0.2.4.7-alpha. Patch by "teor".
    - Fix a memory leak when using AutomapHostsOnResolve. Fixes bug
      14195; bugfix on 0.1.0.1-rc.

  o Minor bugfixes (compilation):
    - Build without warnings with the stock OpenSSL srtp.h header, which
      has a duplicate declaration of SSL_get_selected_srtp_profile().
      Fixes bug 14220; this is OpenSSL's bug, not ours.

  o Minor bugfixes (directory authority):
    - Allow directory authorities to fetch more data from one another if
      they find themselves missing lots of votes. Previously, they had
      been bumping against the 10 MB queued data limit. Fixes bug 14261;
      bugfix on 0.1.2.5-alpha.
    - Enlarge the buffer to read bwauth generated files to avoid an
      issue when parsing the file in dirserv_read_measured_bandwidths().
      Fixes bug 14125; bugfix on 0.2.2.1-alpha.

  o Minor bugfixes (statistics):
    - Increase period over which bandwidth observations are aggregated
      from 15 minutes to 4 hours. Fixes bug 13988; bugfix on 0.0.8pre1.

  o Minor bugfixes (preventative security, C safety):
    - When reading a hexadecimal, base-32, or base-64 encoded value from
      a string, always overwrite the whole output buffer. This prevents
      some bugs where we would look at (but fortunately, not reveal)
      uninitialized memory on the stack. Fixes bug 14013; bugfix on all
      versions of Tor.


Changes in version 0.2.4.26 - 2015-03-17
  Tor 0.2.4.26 includes an updated list of directory authorities.  It
  also backports a couple of stability and security bugfixes from 0.2.5
  and beyond.

  o Directory authority changes:
    - Remove turtles as a directory authority.
    - Add longclaw as a new (v3) directory authority. This implements
      ticket 13296. This keeps the directory authority count at 9.
    - The directory authority Faravahar has a new IP address. This
      closes ticket 14487.

  o Major bugfixes (exit node stability, also in 0.2.6.3-alpha):
    - Fix an assertion failure that could occur under high DNS load.
      Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
      diagnosed and fixed by "cypherpunks".

  o Major bugfixes (relay, stability, possible security, also in 0.2.6.4-rc):
    - Fix a bug that could lead to a relay crashing with an assertion
      failure if a buffer of exactly the wrong layout was passed to
      buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
      0.2.0.10-alpha. Patch from 'cypherpunks'.
    - Do not assert if the 'data' pointer on a buffer is advanced to the
      very end of the buffer; log a BUG message instead. Only assert if
      it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.

  o Minor features (geoip):
    - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the March 3 2015 Maxmind GeoLite2
      Country database.

Changes in version 0.2.6.4-rc - 2015-03-09
  Tor 0.2.6.4-alpha fixes an issue in the directory code that an
  attacker might be able to use in order to crash certain Tor
  directories. It also resolves some minor issues left over from, or
  introduced in, Tor 0.2.6.3-alpha or earlier.

  o Major bugfixes (crash, OSX, security):
    - Fix a remote denial-of-service opportunity caused by a bug in
      OSX's _strlcat_chk() function. Fixes bug 15205; bug first appeared
      in OSX 10.9.

  o Major bugfixes (relay, stability, possible security):
    - Fix a bug that could lead to a relay crashing with an assertion
      failure if a buffer of exactly the wrong layout is passed to
      buf_pullup() at exactly the wrong time. Fixes bug 15083; bugfix on
      0.2.0.10-alpha. Patch from "cypherpunks".
    - Do not assert if the 'data' pointer on a buffer is advanced to the
      very end of the buffer; log a BUG message instead. Only assert if
      it is past that point. Fixes bug 15083; bugfix on 0.2.0.10-alpha.

  o Major bugfixes (FreeBSD IPFW transparent proxy):
    - Fix address detection with FreeBSD transparent proxies, when
      "TransProxyType ipfw" is in use. Fixes bug 15064; bugfix
      on 0.2.5.4-alpha.

  o Major bugfixes (Linux seccomp2 sandbox):
    - Pass IPPROTO_TCP rather than 0 to socket(), so that the Linux
      seccomp2 sandbox doesn't fail. Fixes bug 14989; bugfix
      on 0.2.6.3-alpha.
    - Allow AF_UNIX hidden services to be used with the seccomp2
      sandbox. Fixes bug 15003; bugfix on 0.2.6.3-alpha.
    - Upon receiving sighup with the seccomp2 sandbox enabled, do not
      crash during attempts to call wait4. Fixes bug 15088; bugfix on
      0.2.5.1-alpha. Patch from "sanic".

  o Minor features (controller):
    - Messages about problems in the bootstrap process now include
      information about the server we were trying to connect to when we
      noticed the problem. Closes ticket 15006.

  o Minor features (geoip):
    - Update geoip to the March 3 2015 Maxmind GeoLite2 Country database.
    - Update geoip6 to the March 3 2015 Maxmind GeoLite2
      Country database.

  o Minor features (logs):
    - Quiet some log messages in the heartbeat and at startup. Closes
      ticket 14950.

  o Minor bugfixes (certificate handling):
    - If an authority operator accidentally makes a signing certificate
      with a future publication time, do not discard its real signing
      certificates. Fixes bug 11457; bugfix on 0.2.0.3-alpha.
    - Remove any old authority certificates that have been superseded
      for at least two days. Previously, we would keep superseded
      certificates until they expired, if they were published close in
      time to the certificate that superseded them. Fixes bug 11454;
      bugfix on 0.2.1.8-alpha.

  o Minor bugfixes (compilation):
    - Fix a compilation warning on s390. Fixes bug 14988; bugfix
      on 0.2.5.2-alpha.
    - Fix a compilation warning on FreeBSD. Fixes bug 15151; bugfix
      on 0.2.6.2-alpha.

  o Minor bugfixes (testing):
    - Fix endianness issues in unit test for resolve_my_address() to
      have it pass on big endian systems. Fixes bug 14980; bugfix on
      Tor 0.2.6.3-alpha.
    - Avoid a side-effect in a tor_assert() in the unit tests. Fixes bug
      15188; bugfix on 0.1.2.3-alpha. Patch from Tom van der Woerdt.
    - When running the new 'make test-stem' target, use the configured
      python binary. Fixes bug 15037; bugfix on 0.2.6.3-alpha. Patch
      from "cypherpunks".
    - When running the zero-length-keys tests, do not use the default
      torrc file. Fixes bug 15033; bugfix on 0.2.6.3-alpha. Reported
      by "reezer".

  o Directory authority IP change:
    - The directory authority Faravahar has a new IP address. This
      closes ticket 14487.

  o Removed code:
    - Remove some lingering dead code that once supported mempools.
      Mempools were disabled by default in 0.2.5, and removed entirely
      in 0.2.6.3-alpha. Closes more of ticket 14848; patch
      by "cypherpunks".


Changes in version 0.2.6.3-alpha - 2015-02-19
  Tor 0.2.6.3-alpha is the third (and hopefully final) alpha release in
  the 0.2.6.x series. It introduces support for more kinds of sockets,
  makes it harder to accidentally run an exit, improves our
  multithreading backend, incorporates several fixes for the
  AutomapHostsOnResolve option, and fixes numerous other bugs besides.

  If no major regressions or security holes are found in this version,
  the next version will be a release candidate.

  o Deprecated versions:
    - Tor relays older than 0.2.4.18-rc are no longer allowed to
      advertise themselves on the network. Closes ticket 13555.

  o Major features (security, unix domain sockets):
    - Allow SocksPort to be an AF_UNIX Unix Domain Socket. Now high risk
      applications can reach Tor without having to create AF_INET or
      AF_INET6 sockets, meaning they can completely disable their
      ability to make non-Tor network connections. To create a socket of
      this type, use "SocksPort unix:/path/to/socket". Implements
      ticket 12585.
    - Support mapping hidden service virtual ports to AF_UNIX sockets.
      The syntax is "HiddenServicePort 80 unix:/path/to/socket".
      Implements ticket 11485.

  o Major features (changed defaults):
    - Prevent relay operators from unintentionally running exits: When a
      relay is configured as an exit node, we now warn the user unless
      the "ExitRelay" option is set to 1. We warn even more loudly if
      the relay is configured with the default exit policy, since this
      can indicate accidental misconfiguration. Setting "ExitRelay 0"
      stops Tor from running as an exit relay. Closes ticket 10067.

  o Major features (directory system):
    - When downloading server- or microdescriptors from a directory
      server, we no longer launch multiple simultaneous requests to the
      same server. This reduces load on the directory servers,
      especially when directory guards are in use. Closes ticket 9969.
    - When downloading server- or microdescriptors over a tunneled
      connection, do not limit the length of our requests to what the
      Squid proxy is willing to handle. Part of ticket 9969.
    - Authorities can now vote on the correct digests and latest
      versions for different software packages. This allows packages
      that include Tor to use the Tor authority system as a way to get
      notified of updates and their correct digests. Implements proposal
      227. Closes ticket 10395.

  o Major features (guards):
    - Introduce the Guardfraction feature to improves load balancing on
      guard nodes. Specifically, it aims to reduce the traffic gap that
      guard nodes experience when they first get the Guard flag. This is
      a required step if we want to increase the guard lifetime to 9
      months or greater.  Closes ticket 9321.

  o Major features (performance):
    - Make the CPU worker implementation more efficient by avoiding the
      kernel and lengthening pipelines. The original implementation used
      sockets to transfer data from the main thread to the workers, and
      didn't allow any thread to be assigned more than a single piece of
      work at once. The new implementation avoids communications
      overhead by making requests in shared memory, avoiding kernel IO
      where possible, and keeping more requests in flight at once.
      Implements ticket 9682.

  o Major features (relay):
    - Raise the minimum acceptable configured bandwidth rate for bridges
      to 50 KiB/sec and for relays to 75 KiB/sec. (The old values were
      20 KiB/sec.) Closes ticket 13822.

  o Major bugfixes (exit node stability):
    - Fix an assertion failure that could occur under high DNS load.
      Fixes bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr";
      diagnosed and fixed by "cypherpunks".

  o Major bugfixes (mixed relay-client operation):
    - When running as a relay and client at the same time (not
      recommended), if we decide not to use a new guard because we want
      to retry older guards, only close the locally-originating circuits
      passing through that guard. Previously we would close all the
      circuits through that guard. Fixes bug 9819; bugfix on
      0.2.1.1-alpha. Reported by "skruffy".

  o Minor features (build):
    - New --disable-system-torrc compile-time option to prevent Tor from
      looking for the system-wide torrc or torrc-defaults files.
      Resolves ticket 13037.

  o Minor features (controller):
    - Include SOCKS_USERNAME and SOCKS_PASSWORD values in controller
      events so controllers can observe circuit isolation inputs. Closes
      ticket 8405.
    - ControlPort now supports the unix:/path/to/socket syntax as an
      alternative to the ControlSocket option, for consistency with
      SocksPort and HiddenServicePort. Closes ticket 14451.
    - New "GETINFO bw-event-cache" to get information about recent
      bandwidth events. Closes ticket 14128. Useful for controllers to
      get recent bandwidth history after the fix for ticket 13988.

  o Minor features (Denial of service resistance):
    - Count the total number of bytes used storing hidden service
      descriptors against the value of MaxMemInQueues. If we're low on
      memory, and more than 20% of our memory is used holding hidden
      service descriptors, free them until no more than 10% of our
      memory holds hidden service descriptors. Free the least recently
      fetched descriptors first. Resolves ticket 13806.
    - When we have recently been under memory pressure (over 3/4 of
      MaxMemInQueues is allocated), then allocate smaller zlib objects
      for small requests. Closes ticket 11791.

  o Minor features (geoip):
    - Update geoip and geoip6 files to the January 7 2015 Maxmind
      GeoLite2 Country database.

  o Minor features (guard nodes):
    - Reduce the time delay before saving guard status to disk from 10
      minutes to 30 seconds (or from one hour to 10 minutes if
      AvoidDiskWrites is set). Closes ticket 12485.

  o Minor features (hidden service):
    - Make Sybil attacks against hidden services harder by changing the
      minimum time required to get the HSDir flag from 25 hours up to 96
      hours. Addresses ticket 14149.
    - New option "HiddenServiceAllowUnknownPorts" to allow hidden
      services to disable the anti-scanning feature introduced in
      0.2.6.2-alpha. With this option not set, a connection to an
      unlisted port closes the circuit. With this option set, only a
      RELAY_DONE cell is sent. Closes ticket 14084.

  o Minor features (interface):
    - Implement "-f -" command-line option to read torrc configuration
      from standard input, if you don't want to store the torrc file in
      the file system. Implements feature 13865.

  o Minor features (logging):
    - Add a count of unique clients to the bridge heartbeat message.
      Resolves ticket 6852.
    - Suppress "router info incompatible with extra info" message when
      reading extrainfo documents from cache. (This message got loud
      around when we closed bug 9812 in 0.2.6.2-alpha.) Closes
      ticket 13762.
    - Elevate hidden service authorized-client message from DEBUG to
      INFO. Closes ticket 14015.

  o Minor features (stability):
    - Add assertions in our hash-table iteration code to check for
      corrupted values that could cause infinite loops. Closes
      ticket 11737.

  o Minor features (systemd):
    - Various improvements and modernizations in systemd hardening
      support. Closes ticket 13805. Patch from Craig Andrews.

  o Minor features (testing networks):
    - Drop the minimum RendPostPeriod on a testing network to 5 seconds,
      and the default on a testing network to 2 minutes. Drop the
      MIN_REND_INITIAL_POST_DELAY on a testing network to 5 seconds, but
      keep the default on a testing network at 30 seconds. This reduces
      HS bootstrap time to around 25 seconds. Also, change the default
      time in test-network.sh to match. Closes ticket 13401. Patch
      by "teor".
    - Create TestingDirAuthVoteHSDir to correspond to
      TestingDirAuthVoteExit/Guard. Ensures that authorities vote the
      HSDir flag for the listed relays regardless of uptime or ORPort
      connectivity. Respects the value of VoteOnHidServDirectoriesV2.
      Partial implementation for ticket 14067. Patch by "teor".

  o Minor features (tor2web mode):
    - Introduce the config option Tor2webRendezvousPoints, which allows
      clients in Tor2webMode to select a specific Rendezvous Point to be
      used in HS circuits. This might allow better performance for
      Tor2Web nodes. Implements ticket 12844.

  o Minor bugfixes (client DNS):
    - Report the correct cached DNS expiration times on SOCKS port or in
      DNS replies. Previously, we would report everything as "never
      expires." Fixes bug 14193; bugfix on 0.2.3.17-beta.
    - Avoid a small memory leak when we find a cached answer for a
      reverse DNS lookup in a client-side DNS cache. (Remember, client-
      side DNS caching is off by default, and is not recommended.) Fixes
      bug 14259; bugfix on 0.2.0.1-alpha.

  o Minor bugfixes (client, automapping):
    - Avoid crashing on torrc lines for VirtualAddrNetworkIPv[4|6] when
      no value follows the option. Fixes bug 14142; bugfix on
      0.2.4.7-alpha. Patch by "teor".
    - Fix a memory leak when using AutomapHostsOnResolve. Fixes bug
      14195; bugfix on 0.1.0.1-rc.
    - Prevent changes to other options from removing the wildcard value
      "." from "AutomapHostsSuffixes". Fixes bug 12509; bugfix
      on 0.2.0.1-alpha.
    - Allow MapAddress and AutomapHostsOnResolve to work together when
      an address is mapped into another address type (like .onion) that
      must be automapped at resolve time. Fixes bug 7555; bugfix
      on 0.2.0.1-alpha.

  o Minor bugfixes (client, bridges):
    - When we are using bridges and we had a network connectivity
      problem, only retry connecting to our currently configured
      bridges, not all bridges we know about and remember using. Fixes
      bug 14216; bugfix on 0.2.2.17-alpha.

  o Minor bugfixes (client, IPv6):
    - Reject socks requests to literal IPv6 addresses when IPv6Traffic
      flag is not set; and not because the NoIPv4Traffic flag was set.
      Previously we'd looked at the NoIPv4Traffic flag for both types of
      literal addresses. Fixes bug 14280; bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (compilation):
    - The address of an array in the middle of a structure will always
      be non-NULL. clang recognises this and complains. Disable the
      tautologous and redundant check to silence this warning. Fixes bug
      14001; bugfix on 0.2.1.2-alpha.
    - Avoid warnings when building with systemd 209 or later. Fixes bug
      14072; bugfix on 0.2.6.2-alpha. Patch from "h.venev".
    - Compile correctly with (unreleased) OpenSSL 1.1.0 headers.
      Addresses ticket 14188.
    - Build without warnings with the stock OpenSSL srtp.h header, which
      has a duplicate declaration of SSL_get_selected_srtp_profile().
      Fixes bug 14220; this is OpenSSL's bug, not ours.
    - Do not compile any code related to Tor2Web mode when Tor2Web mode
      is not enabled at compile time. Previously, this code was included
      in a disabled state. See discussion on ticket 12844.
    - Remove the --disable-threads configure option again. It was
      accidentally partially reintroduced in 29ac883606d6d. Fixes bug
      14819; bugfix on 0.2.6.2-alpha.

  o Minor bugfixes (controller):
    - Report "down" in response to the "GETINFO entry-guards" command
      when relays are down with an unreachable_since value. Previously,
      we would report "up". Fixes bug 14184; bugfix on 0.1.2.2-alpha.
    - Avoid crashing on a malformed EXTENDCIRCUIT command. Fixes bug
      14116; bugfix on 0.2.2.9-alpha.
    - Add a code for the END_CIRC_REASON_IP_NOW_REDUNDANT circuit close
      reason. Fixes bug 14207; bugfix on 0.2.6.2-alpha.

  o Minor bugfixes (directory authority):
    - Allow directory authorities to fetch more data from one another if
      they find themselves missing lots of votes. Previously, they had
      been bumping against the 10 MB queued data limit. Fixes bug 14261;
      bugfix on 0.1.2.5-alpha.
    - Do not attempt to download extrainfo documents which we will be
      unable to validate with a matching server descriptor. Fixes bug
      13762; bugfix on 0.2.0.1-alpha.
    - Fix a bug that was truncating AUTHDIR_NEWDESC events sent to the
      control port. Fixes bug 14953; bugfix on 0.2.0.1-alpha.
    - Enlarge the buffer to read bwauth generated files to avoid an
      issue when parsing the file in dirserv_read_measured_bandwidths().
      Fixes bug 14125; bugfix on 0.2.2.1-alpha.

  o Minor bugfixes (file handling):
    - Stop failing when key files are zero-length. Instead, generate new
      keys, and overwrite the empty key files. Fixes bug 13111; bugfix
      on all versions of Tor. Patch by "teor".
    - Stop generating a fresh .old RSA onion key file when the .old file
      is missing. Fixes part of 13111; bugfix on 0.0.6rc1.
    - Avoid overwriting .old key files with empty key files.
    - Skip loading zero-length extrainfo store, router store, stats,
      state, and key files.
    - Avoid crashing when trying to reload a torrc specified as a
      relative path with RunAsDaemon turned on. Fixes bug 13397; bugfix
      on 0.2.3.11-alpha.

  o Minor bugfixes (hidden services):
    - Close the introduction circuit when we have no more usable intro
      points, instead of waiting for it to time out. This also ensures
      that no follow-up HS descriptor fetch is triggered when the
      circuit eventually times out. Fixes bug 14224; bugfix on 0.0.6.
    - When fetching a hidden service descriptor for a down service that
      was recently up, do not keep refetching until we try the same
      replica twice in a row. Fixes bug 14219; bugfix on 0.2.0.10-alpha.
    - Successfully launch Tor with a nonexistent hidden service
      directory. Our fix for bug 13942 didn't catch this case. Fixes bug
      14106; bugfix on 0.2.6.2-alpha.

  o Minor bugfixes (logging):
    - Avoid crashing when there are more log domains than entries in
      domain_list. Bugfix on 0.2.3.1-alpha.
    - Add a string representation for LD_SCHED. Fixes bug 14740; bugfix
      on 0.2.6.1-alpha.
    - Don't log messages to stdout twice when starting up. Fixes bug
      13993; bugfix on 0.2.6.1-alpha.

  o Minor bugfixes (parsing):
    - Stop accepting milliseconds (or other junk) at the end of
      descriptor publication times. Fixes bug 9286; bugfix on 0.0.2pre25.
    - Support two-number and three-number version numbers correctly, in
      case we change the Tor versioning system in the future. Fixes bug
      13661; bugfix on 0.0.8pre1.

  o Minor bugfixes (path counting):
    - When deciding whether the consensus lists any exit nodes, count
      the number listed in the consensus, not the number we have
      descriptors for. Fixes part of bug 14918; bugfix on 0.2.6.2-alpha.
    - When deciding whether we have any exit nodes, only examine
      ExitNodes when the ExitNodes option is actually set. Fixes part of
      bug 14918; bugfix on 0.2.6.2-alpha.
    - Get rid of redundant and possibly scary warnings that we are
      missing directory information while we bootstrap. Fixes part of
      bug 14918; bugfix on 0.2.6.2-alpha.

  o Minor bugfixes (portability):
    - Fix the ioctl()-based network interface lookup code so that it
      will work on systems that have variable-length struct ifreq, for
      example Mac OS X.
    - Fix scheduler compilation on targets where char is unsigned. Fixes
      bug 14764; bugfix on 0.2.6.2-alpha. Reported by Christian Kujau.

  o Minor bugfixes (sandbox):
    - Allow glibc fatal errors to be sent to stderr before Tor exits.
      Previously, glibc would try to write them to /dev/tty, and the
      sandbox would trap the call and make Tor exit prematurely. Fixes
      bug 14759; bugfix on 0.2.5.1-alpha.

  o Minor bugfixes (shutdown):
    - When shutting down, always call event_del() on lingering read or
      write events before freeing them. Otherwise, we risk double-frees
      or read-after-frees in event_base_free(). Fixes bug 12985; bugfix
      on 0.1.0.2-rc.

  o Minor bugfixes (small memory leaks):
    - Avoid leaking memory when using IPv6 virtual address mappings.
      Fixes bug 14123; bugfix on 0.2.4.7-alpha. Patch by Tom van
      der Woerdt.

  o Minor bugfixes (statistics):
    - Increase period over which bandwidth observations are aggregated
      from 15 minutes to 4 hours. Fixes bug 13988; bugfix on 0.0.8pre1.

  o Minor bugfixes (systemd support):
    - Fix detection and operation of systemd watchdog. Fixes part of bug
      14141; bugfix on 0.2.6.2-alpha. Patch from Tomasz Torcz.
    - Run correctly under systemd with the RunAsDaemon option set. Fixes
      part of bug 14141; bugfix on 0.2.5.7-rc. Patch from Tomasz Torcz.
    - Inform the systemd supervisor about more changes in the Tor
      process status. Implements part of ticket 14141. Patch from
      Tomasz Torcz.
    - Cause the "--disable-systemd" option to actually disable systemd
      support. Fixes bug 14350; bugfix on 0.2.6.2-alpha. Patch
      from "blueness".

  o Minor bugfixes (TLS):
    - Check more thoroughly throughout the TLS code for possible
      unlogged TLS errors. Possible diagnostic or fix for bug 13319.

  o Minor bugfixes (transparent proxy):
    - Use getsockname, not getsockopt, to retrieve the address for a
      TPROXY-redirected connection. Fixes bug 13796; bugfix
      on 0.2.5.2-alpha.

  o Code simplification and refactoring:
    - Move fields related to isolating and configuring client ports into
      a shared structure. Previously, they were duplicated across
      port_cfg_t, listener_connection_t, and edge_connection_t. Failure
      to copy them correctly had been the cause of at least one bug in
      the past. Closes ticket 8546.
    - Refactor the get_interface_addresses_raw() doom-function into
      multiple smaller and simpler subfunctions. Cover the resulting
      subfunctions with unit-tests. Fixes a significant portion of
      issue 12376.
    - Remove workaround in dirserv_thinks_router_is_hs_dir() that was
      only for version <= 0.2.2.24 which is now deprecated. Closes
      ticket 14202.
    - Remove a test for a long-defunct broken version-one
      directory server.

  o Documentation:
    - Adding section on OpenBSD to our TUNING document. Thanks to mmcc
      for writing the OpenBSD-specific tips. Resolves ticket 13702.
    - Make the tor-resolve documentation match its help string and its
      options. Resolves part of ticket 14325.
    - Log a more useful error message from tor-resolve when failing to
      look up a hidden service address. Resolves part of ticket 14325.

  o Downgraded warnings:
    - Don't warn when we've attempted to contact a relay using the wrong
      ntor onion key. Closes ticket 9635.

  o Removed features:
    - To avoid confusion with the "ExitRelay" option, "ExitNode" is no
      longer silently accepted as an alias for "ExitNodes".
    - The --enable-mempool and --enable-buf-freelists options, which
      were originally created to work around bad malloc implementations,
      no longer exist. They were off-by-default in 0.2.5. Closes
      ticket 14848.

  o Testing:
    - Make the checkdir/perms test complete successfully even if the
      global umask is not 022. Fixes bug 14215; bugfix on 0.2.6.2-alpha.
    - Test that tor does not fail when key files are zero-length. Check
      that tor generates new keys, and overwrites the empty key files.
    - Test that tor generates new keys when keys are missing
      (existing behavior).
    - Test that tor does not overwrite key files that already contain
      data (existing behavior). Tests bug 13111. Patch by "teor".
    - New "make test-stem" target to run stem integration tests.
      Requires that the "STEM_SOURCE_DIR" environment variable be set.
      Closes ticket 14107.
    - Make the test_cmdline_args.py script work correctly on Windows.
      Patch from Gisle Vanem.
    - Move the slower unit tests into a new "./src/test/test-slow"
      binary that can be run independently of the other tests. Closes
      ticket 13243.
    - Avoid undefined behavior when sampling huge values from the
      Laplace distribution. This made unittests fail on Raspberry Pi.
      Bug found by Device. Fixes bug 14090; bugfix on 0.2.6.2-alpha.


Changes in version 0.2.6.2-alpha - 2014-12-31
  Tor 0.2.6.2-alpha is the second alpha release in the 0.2.6.x series.
  It introduces a major new backend for deciding when to send cells on
  channels, which should lead down the road to big performance
  increases. It contains security and statistics features for better
  work on hidden services, and numerous bugfixes.

  This release contains many new unit tests, along with major
  performance improvements for running testing networks using Chutney.
  Thanks to a series of patches contributed by "teor", testing networks
  should now bootstrap in seconds, rather than minutes.

  o Major features (relay, infrastructure):
    - Complete revision of the code that relays use to decide which cell
      to send next. Formerly, we selected the best circuit to write on
      each channel, but we didn't select among channels in any
      sophisticated way. Now, we choose the best circuits globally from
      among those whose channels are ready to deliver traffic.

      This patch implements a new inter-cmux comparison API, a global
      high/low watermark mechanism and a global scheduler loop for
      transmission prioritization across all channels as well as among
      circuits on one channel. This schedule is currently tuned to
      (tolerantly) avoid making changes in network performance, but it
      should form the basis for major circuit performance increases in
      the future. Code by Andrea; tuning by Rob Jansen; implements
      ticket 9262.

  o Major features (hidden services):
    - Make HS port scanning more difficult by immediately closing the
      circuit when a user attempts to connect to a nonexistent port.
      Closes ticket 13667.
    - Add a HiddenServiceStatistics option that allows Tor relays to
      gather and publish statistics about the overall size and volume of
      hidden service usage. Specifically, when this option is turned on,
      an HSDir will publish an approximate number of hidden services
      that have published descriptors to it the past 24 hours. Also, if
      a relay has acted as a hidden service rendezvous point, it will
      publish the approximate amount of rendezvous cells it has relayed
      the past 24 hours. The statistics themselves are obfuscated so
      that the exact values cannot be derived. For more details see
      proposal 238, "Better hidden service stats from Tor relays". This
      feature is currently disabled by default. Implements feature 13192.

  o Major bugfixes (client, automap):
    - Repair automapping with IPv6 addresses. This automapping should
      have worked previously, but one piece of debugging code that we
      inserted to detect a regression actually caused the regression to
      manifest itself again. Fixes bug 13811 and bug 12831; bugfix on
      0.2.4.7-alpha. Diagnosed and fixed by Francisco Blas
      Izquierdo Riera.

  o Major bugfixes (hidden services):
    - When closing an introduction circuit that was opened in parallel
      with others, don't mark the introduction point as unreachable.
      Previously, the first successful connection to an introduction
      point would make the other introduction points get marked as
      having timed out. Fixes bug 13698; bugfix on 0.0.6rc2.

  o Directory authority changes:
    - Remove turtles as a directory authority.
    - Add longclaw as a new (v3) directory authority. This implements
      ticket 13296. This keeps the directory authority count at 9.

  o Major removed features:
    - Tor clients no longer support connecting to hidden services
      running on Tor 0.2.2.x and earlier; the Support022HiddenServices
      option has been removed. (There shouldn't be any hidden services
      running these versions on the network.) Closes ticket 7803.

  o Minor features (client):
    - Validate hostnames in SOCKS5 requests more strictly. If SafeSocks
      is enabled, reject requests with IP addresses as hostnames.
      Resolves ticket 13315.

  o Minor features (controller):
    - Add a "SIGNAL HEARTBEAT" controller command that tells Tor to
      write an unscheduled heartbeat message to the log. Implements
      feature 9503.

  o Minor features (geoip):
    - Update geoip and geoip6 to the November 15 2014 Maxmind GeoLite2
      Country database.

  o Minor features (hidden services):
    - When re-enabling the network, don't try to build introduction
      circuits until we have successfully built a circuit. This makes
      hidden services come up faster when the network is re-enabled.
      Patch from "akwizgran". Closes ticket 13447.
    - When we fail to retrieve a hidden service descriptor, send the
      controller an "HS_DESC FAILED" controller event. Implements
      feature 13212.
    - New HiddenServiceDirGroupReadable option to cause hidden service
      directories and hostname files to be created group-readable. Patch
      from "anon", David Stainton, and "meejah". Closes ticket 11291.

  o Minor features (systemd):
    - Where supported, when running with systemd, report successful
      startup to systemd. Part of ticket 11016. Patch by Michael Scherer.
    - When running with systemd, support systemd watchdog messages. Part
      of ticket 11016. Patch by Michael Scherer.

  o Minor features (transparent proxy):
    - Update the transparent proxy option checks to allow for both ipfw
      and pf on OS X. Closes ticket 14002.
    - Use the correct option when using IPv6 with transparent proxy
      support on Linux. Resolves 13808. Patch by Francisco Blas
      Izquierdo Riera.

  o Minor bugfixes (preventative security, C safety):
    - When reading a hexadecimal, base-32, or base-64 encoded value from
      a string, always overwrite the whole output buffer. This prevents
      some bugs where we would look at (but fortunately, not reveal)
      uninitialized memory on the stack. Fixes bug 14013; bugfix on all
      versions of Tor.
    - Clear all memory targetted by tor_addr_{to,from}_sockaddr(), not
      just the part that's used. This makes it harder for data leak bugs
      to occur in the event of other programming failures. Resolves
      ticket 14041.

  o Minor bugfixes (client, microdescriptors):
    - Use a full 256 bits of the SHA256 digest of a microdescriptor when
      computing which microdescriptors to download. This keeps us from
      erroneous download behavior if two microdescriptor digests ever
      have the same first 160 bits. Fixes part of bug 13399; bugfix
      on 0.2.3.1-alpha.
    - Reset a router's status if its microdescriptor digest changes,
      even if the first 160 bits remain the same. Fixes part of bug
      13399; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (compilation):
    - Silence clang warnings under --enable-expensive-hardening,
      including implicit truncation of 64 bit values to 32 bit, const
      char assignment to self, tautological compare, and additional
      parentheses around equality tests. Fixes bug 13577; bugfix
      on 0.2.5.4-alpha.
    - Fix a clang warning about checking whether an address in the
      middle of a structure is NULL. Fixes bug 14001; bugfix
      on 0.2.1.2-alpha.

  o Minor bugfixes (hidden services):
    - Correctly send a controller event when we find that a rendezvous
      circuit has finished. Fixes bug 13936; bugfix on 0.1.1.5-alpha.
    - Pre-check directory permissions for new hidden-services to avoid
      at least one case of "Bug: Acting on config options left us in a
      broken state. Dying." Fixes bug 13942; bugfix on 0.0.6pre1.
    - When adding a new hidden service (for example, via SETCONF), Tor
      no longer congratulates the user for running a relay. Fixes bug
      13941; bugfix on 0.2.6.1-alpha.
    - When fetching hidden service descriptors, we now check not only
      for whether we got the hidden service we had in mind, but also
      whether we got the particular descriptors we wanted. This prevents
      a class of inefficient but annoying DoS attacks by hidden service
      directories. Fixes bug 13214; bugfix on 0.2.1.6-alpha. Reported
      by "special".

  o Minor bugfixes (Linux seccomp2 sandbox):
    - Make transparent proxy support work along with the seccomp2
      sandbox. Fixes part of bug 13808; bugfix on 0.2.5.1-alpha. Patch
      by Francisco Blas Izquierdo Riera.
    - Fix a memory leak in tor-resolve when running with the sandbox
      enabled. Fixes bug 14050; bugfix on 0.2.5.9-rc.

  o Minor bugfixes (logging):
    - Downgrade warnings about RSA signature failures to info log level.
      Emit a warning when an extra info document is found incompatible
      with a corresponding router descriptor. Fixes bug 9812; bugfix
      on 0.0.6rc3.
    - Make connection_ap_handshake_attach_circuit() log the circuit ID
      correctly. Fixes bug 13701; bugfix on 0.0.6.

  o Minor bugfixes (misc):
    - Stop allowing invalid address patterns like "*/24" that contain
      both a wildcard address and a bit prefix length. This affects all
      our address-range parsing code. Fixes bug 7484; bugfix
      on 0.0.2pre14.

  o Minor bugfixes (testing networks, fast startup):
    - Allow Tor to build circuits using a consensus with no exits. If
      the consensus has no exits (typical of a bootstrapping test
      network), allow Tor to build circuits once enough descriptors have
      been downloaded. This assists in bootstrapping a testing Tor
      network. Fixes bug 13718; bugfix on 0.2.4.10-alpha. Patch
      by "teor".
    - When V3AuthVotingInterval is low, give a lower If-Modified-Since
      header to directory servers. This allows us to obtain consensuses
      promptly when the consensus interval is very short. This assists
      in bootstrapping a testing Tor network. Fixes parts of bugs 13718
      and 13963; bugfix on 0.2.0.3-alpha. Patch by "teor".
    - Stop assuming that private addresses are local when checking
      reachability in a TestingTorNetwork. Instead, when testing, assume
      all OR connections are remote. (This is necessary due to many test
      scenarios running all relays on localhost.) This assists in
      bootstrapping a testing Tor network. Fixes bug 13924; bugfix on
      0.1.0.1-rc. Patch by "teor".
    - Avoid building exit circuits from a consensus with no exits. Now
      thanks to our fix for 13718, we accept a no-exit network as not
      wholly lost, but we need to remember not to try to build exit
      circuits on it. Closes ticket 13814; patch by "teor".
    - Stop requiring exits to have non-zero bandwithcapacity in a
      TestingTorNetwork. Instead, when TestingMinExitFlagThreshold is 0,
      ignore exit bandwidthcapacity. This assists in bootstrapping a
      testing Tor network. Fixes parts of bugs 13718 and 13839; bugfix
      on 0.2.0.3-alpha. Patch by "teor".
    - Add "internal" to some bootstrap statuses when no exits are
      available. If the consensus does not contain Exits, Tor will only
      build internal circuits. In this case, relevant statuses will
      contain the word "internal" as indicated in the Tor control-
       spec.txt. When bootstrap completes, Tor will be ready to build
      internal circuits. If a future consensus contains Exits, exit
      circuits may become available. Fixes part of bug 13718; bugfix on
      0.2.4.10-alpha. Patch by "teor".
    - Decrease minimum consensus interval to 10 seconds when
      TestingTorNetwork is set, or 5 seconds for the first consensus.
      Fix assumptions throughout the code that assume larger intervals.
      Fixes bugs 13718 and 13823; bugfix on 0.2.0.3-alpha. Patch
      by "teor".
    - Avoid excluding guards from path building in minimal test
      networks, when we're in a test network and excluding guards would
      exclude all relays. This typically occurs in incredibly small tor
      networks, and those using "TestingAuthVoteGuard *". Fixes part of
      bug 13718; bugfix on 0.1.1.11-alpha. Patch by "teor".

  o Code simplification and refactoring:
    - Stop using can_complete_circuits as a global variable; access it
      with a function instead.
    - Avoid using operators directly as macro arguments: this lets us
      apply coccinelle transformations to our codebase more directly.
      Closes ticket 13172.
    - Combine the functions used to parse ClientTransportPlugin and
      ServerTransportPlugin into a single function. Closes ticket 6456.
    - Add inline functions and convenience macros for inspecting channel
      state. Refactor the code to use convenience macros instead of
      checking channel state directly. Fixes issue 7356.
    - Document all members of was_router_added_t and rename
      ROUTER_WAS_NOT_NEW to ROUTER_IS_ALREADY_KNOWN to make it less
      confusable with ROUTER_WAS_TOO_OLD. Fixes issue 13644.
    - In connection_exit_begin_conn(), use END_CIRC_REASON_TORPROTOCOL
      constant instead of hardcoded value. Fixes issue 13840.
    - Refactor our generic strmap and digestmap types into a single
      implementation, so that we can add a new digest256map
      type trivially.

  o Documentation:
    - Document the bridge-authority-only 'networkstatus-bridges' file.
      Closes ticket 13713; patch from "tom".
    - Fix typo in PredictedPortsRelevanceTime option description in
      manpage. Resolves issue 13707.
    - Stop suggesting that users specify relays by nickname: it isn't a
      good idea. Also, properly cross-reference how to specify relays in
      all parts of manual documenting options that take a list of
      relays. Closes ticket 13381.
    - Clarify the HiddenServiceDir option description in manpage to make
      it clear that relative paths are taken with respect to the current
      working directory. Also clarify that this behavior is not
      guaranteed to remain indefinitely. Fixes issue 13913.

  o Testing:
    - New tests for many parts of channel, relay, and circuitmux
      functionality. Code by Andrea; part of 9262.
    - New tests for parse_transport_line(). Part of ticket 6456.
    - In the unit tests, use chgrp() to change the group of the unit
      test temporary directory to the current user, so that the sticky
      bit doesn't interfere with tests that check directory groups.
      Closes 13678.
    - Add unit tests for resolve_my_addr(). Part of ticket 12376; patch
      by 'rl1987'.


Changes in version 0.2.6.1-alpha - 2014-10-30
  Tor 0.2.6.1-alpha is the first release in the Tor 0.2.6.x series. It
  includes numerous code cleanups and new tests, and fixes a large
  number of annoying bugs. Out-of-memory conditions are handled better
  than in 0.2.5, pluggable transports have improved proxy support, and
  clients now use optimistic data for contacting hidden services. Also,
  we are now more robust to changes in what we consider a parseable
  directory object, so that tightening restrictions does not have a risk
  of introducing infinite download loops.

  This is the first alpha release in a new series, so expect there to be
  bugs. Users who would rather test out a more stable branch should stay
  with 0.2.5.x for now.

  o New compiler and system requirements:
    - Tor 0.2.6.x requires that your compiler support more of the C99
      language standard than before. The 'configure' script now detects
      whether your compiler supports C99 mid-block declarations and
      designated initializers. If it does not, Tor will not compile.

      We may revisit this requirement if it turns out that a significant
      number of people need to build Tor with compilers that don't
      bother implementing a 15-year-old standard. Closes ticket 13233.
    - Tor no longer supports systems without threading support. When we
      began working on Tor, there were several systems that didn't have
      threads, or where the thread support wasn't able to run the
      threads of a single process on multiple CPUs. That no longer
      holds: every system where Tor needs to run well now has threading
      support. Resolves ticket 12439.

  o Removed platform support:
    - We no longer include special code to build on Windows CE; as far
      as we know, nobody has used Tor on Windows CE in a very long time.
      Closes ticket 11446.

  o Major features (bridges):
    - Expose the outgoing upstream HTTP/SOCKS proxy to pluggable
      transports if they are configured via the "TOR_PT_PROXY"
      environment variable. Implements proposal 232. Resolves
      ticket 8402.

  o Major features (client performance, hidden services):
    - Allow clients to use optimistic data when connecting to a hidden
      service, which should remove a round-trip from hidden service
      initialization. See proposal 181 for details. Implements
      ticket 13211.

  o Major features (directory system):
    - Upon receiving an unparseable directory object, if its digest
      matches what we expected, then don't try to download it again.
      Previously, when we got a descriptor we didn't like, we would keep
      trying to download it over and over. Closes ticket 11243.

  o Major features (sample torrc):
    - Add a new, infrequently-changed "torrc.minimal". This file is
      similar to torrc.sample, but it will change as infrequently as
      possible, for the benefit of users whose systems prompt them for
      intervention whenever a default configuration file is changed.
      Making this change allows us to update torrc.sample to be a more
      generally useful "sample torrc".

  o Major bugfixes (directory authorities):
    - Do not assign the HSDir flag to relays if they are not Valid, or
      currently hibernating. Fixes 12573; bugfix on 0.2.0.10-alpha.

  o Major bugfixes (directory bandwidth performance):
    - Don't flush the zlib buffer aggressively when compressing
      directory information for clients. This should save about 7% of
      the bandwidth currently used for compressed descriptors and
      microdescriptors. Fixes bug 11787; bugfix on 0.1.1.23.

  o Minor features (security, memory wiping):
    - Ensure we securely wipe keys from memory after
      crypto_digest_get_digest and init_curve25519_keypair_from_file
      have finished using them. Resolves ticket 13477.

  o Minor features (security, out-of-memory handling):
    - When handling an out-of-memory condition, allocate less memory for
      temporary data structures. Fixes issue 10115.
    - When handling an out-of-memory condition, consider more types of
      buffers, including those on directory connections, and zlib
      buffers. Resolves ticket 11792.

  o Minor features:
    - When identity keypair is generated for first time, log a
      congratulatory message that links to the new relay lifecycle
      document. Implements feature 10427.

  o Minor features (client):
    - Clients are now willing to send optimistic data (before they
      receive a 'connected' cell) to relays of any version. (Relays
      without support for optimistic data are no longer supported on the
      Tor network.) Resolves ticket 13153.

  o Minor features (directory authorities):
    - Don't list relays with a bandwidth estimate of 0 in the consensus.
      Implements a feature proposed during discussion of bug 13000.
    - In tor-gencert, report an error if the user provides the same
      argument more than once.
    - If a directory authority can't find a best consensus method in the
      votes that it holds, it now falls back to its favorite consensus
      method. Previously, it fell back to method 1. Neither of these is
      likely to get enough signatures, but "fall back to favorite"
      doesn't require us to maintain support an obsolete consensus
      method. Implements part of proposal 215.

  o Minor features (logging):
    - On Unix-like systems, you can now use named pipes as the target of
      the Log option, and other options that try to append to files.
      Closes ticket 12061. Patch from "carlo von lynX".
    - When opening a log file at startup, send it every log message that
      we generated between startup and opening it. Previously, log
      messages that were generated before opening the log file were only
      logged to stdout. Closes ticket 6938.
    - Add a TruncateLogFile option to overwrite logs instead of
      appending to them. Closes ticket 5583.

  o Minor features (portability, Solaris):
    - Threads are no longer disabled by default on Solaris; we believe
      that the versions of Solaris with broken threading support are all
      obsolete by now. Resolves ticket 9495.

  o Minor features (relay):
    - Re-check our address after we detect a changed IP address from
      getsockname(). This ensures that the controller command "GETINFO
      address" will report the correct value. Resolves ticket 11582.
      Patch from "ra".
    - A new AccountingRule option lets Relays set whether they'd like
      AccountingMax to be applied separately to inbound and outbound
      traffic, or applied to the sum of inbound and outbound traffic.
      Resolves ticket 961. Patch by "chobe".

  o Minor features (testing networks):
    - Add the TestingDirAuthVoteExit option, which lists nodes to assign
      the "Exit" flag regardless of their uptime, bandwidth, or exit
      policy. TestingTorNetwork must be set for this option to have any
      effect. Previously, authorities would take up to 35 minutes to
      give nodes the Exit flag in a test network. Partially implements
      ticket 13161.

  o Minor features (validation):
    - Check all date/time values passed to tor_timegm and
      parse_rfc1123_time for validity, taking leap years into account.
      Improves HTTP header validation. Implemented with bug 13476.
    - In correct_tm(), limit the range of values returned by system
      localtime(_r) and gmtime(_r) to be between the years 1 and 8099.
      This means we don't have to deal with negative or too large dates,
      even if a clock is wrong. Otherwise we might fail to read a file
      written by us which includes such a date. Fixes bug 13476.

  o Minor bugfixes (bridge clients):
    - When configured to use a bridge without an identity digest (not
      recommended), avoid launching an extra channel to it when
      bootstrapping. Fixes bug 7733; bugfix on 0.2.4.4-alpha.

  o Minor bugfixes (bridges):
    - When DisableNetwork is set, do not launch pluggable transport
      plugins, and if any are running, terminate them. Fixes bug 13213;
      bugfix on 0.2.3.6-alpha.

  o Minor bugfixes (C correctness):
    - Fix several instances of possible integer overflow/underflow/NaN.
      Fixes bug 13104; bugfix on 0.2.3.1-alpha and later. Patches
      from "teor".
    - In circuit_build_times_calculate_timeout() in circuitstats.c,
      avoid dividing by zero in the pareto calculations. This traps
      under clang's "undefined-trap" sanitizer. Fixes bug 13290; bugfix
      on 0.2.2.2-alpha.
    - Fix an integer overflow in format_time_interval(). Fixes bug
      13393; bugfix on 0.2.0.10-alpha.
    - Set the correct day of year value when the system's localtime(_r)
      or gmtime(_r) functions fail to set struct tm. Not externally
      visible. Fixes bug 13476; bugfix on 0.0.2pre14.
    - Avoid unlikely signed integer overflow in tor_timegm on systems
      with 32-bit time_t. Fixes bug 13476; bugfix on 0.0.2pre14.

  o Minor bugfixes (client):
    - Fix smartlist_choose_node_by_bandwidth() so that relays with the
      BadExit flag are not considered worthy candidates. Fixes bug
      13066; bugfix on 0.1.2.3-alpha.
    - Use the consensus schedule for downloading consensuses, and not
      the generic schedule. Fixes bug 11679; bugfix on 0.2.2.6-alpha.
    - Handle unsupported or malformed SOCKS5 requests properly by
      responding with the appropriate error message before closing the
      connection. Fixes bugs 12971 and 13314; bugfix on 0.0.2pre13.

  o Minor bugfixes (client, torrc):
    - Stop modifying the value of our DirReqStatistics torrc option just
      because we're not a bridge or relay. This bug was causing Tor
      Browser users to write "DirReqStatistics 0" in their torrc files
      as if they had chosen to change the config. Fixes bug 4244; bugfix
      on 0.2.3.1-alpha.
    - When GeoIPExcludeUnknown is enabled, do not incorrectly decide
      that our options have changed every time we SIGHUP. Fixes bug
      9801; bugfix on 0.2.4.10-alpha. Patch from "qwerty1".

  o Minor bugfixes (controller):
    - Return an error when the second or later arguments of the
      "setevents" controller command are invalid events. Previously we
      would return success while silently skipping invalid events. Fixes
      bug 13205; bugfix on 0.2.3.2-alpha. Reported by "fpxnns".

  o Minor bugfixes (directory system):
    - Always believe that v3 directory authorities serve extra-info
      documents, whether they advertise "caches-extra-info" or not.
      Fixes part of bug 11683; bugfix on 0.2.0.1-alpha.
    - When running as a v3 directory authority, advertise that you serve
      extra-info documents so that clients who want them can find them
      from you too. Fixes part of bug 11683; bugfix on 0.2.0.1-alpha.
    - Check the BRIDGE_DIRINFO flag bitwise rather than using equality.
      Previously, directories offering BRIDGE_DIRINFO and some other
      flag (i.e. microdescriptors or extrainfo) would be ignored when
      looking for bridges. Partially fixes bug 13163; bugfix
      on 0.2.0.7-alpha.

  o Minor bugfixes (networking):
    - Check for orconns and use connection_or_close_for_error() rather
      than connection_mark_for_close() directly in the getsockopt()
      failure case of connection_handle_write_impl(). Fixes bug 11302;
      bugfix on 0.2.4.4-alpha.

  o Minor bugfixes (relay):
    - When generating our family list, remove spaces from around the
      entries. Fixes bug 12728; bugfix on 0.2.1.7-alpha.
    - If our previous bandwidth estimate was 0 bytes, allow publishing a
      new relay descriptor immediately. Fixes bug 13000; bugfix
      on 0.1.1.6-alpha.

  o Minor bugfixes (testing networks):
    - Fix TestingDirAuthVoteGuard to properly give out Guard flags in a
      testing network. Fixes bug 13064; bugfix on 0.2.5.2-alpha.
    - Stop using the default authorities in networks which provide both
      AlternateDirAuthority and AlternateBridgeAuthority. Partially
      fixes bug 13163; bugfix on 0.2.0.13-alpha.

  o Minor bugfixes (testing):
    - Stop spawn test failures due to a race condition between the
      SIGCHLD handler updating the process status, and the test reading
      it. Fixes bug 13291; bugfix on 0.2.3.3-alpha.

  o Minor bugfixes (testing, Windows):
    - Avoid passing an extra backslash when creating a temporary
      directory for running the unit tests on Windows. Fixes bug 12392;
      bugfix on 0.2.2.25-alpha. Patch from Gisle Vanem.

  o Minor bugfixes (windows):
    - Remove code to special-case handling of NTE_BAD_KEYSET when
      acquiring windows CryptoAPI context. This error can't actually
      occur for the parameters we're providing. Fixes bug 10816; bugfix
      on 0.0.2pre26.

  o Minor bugfixes (zlib):
    - Avoid truncating a zlib stream when trying to finalize it with an
      empty output buffer. Fixes bug 11824; bugfix on 0.1.1.23.

  o Build fixes:
    - Allow our configure script to build correctly with autoconf 2.62
      again. Fixes bug 12693; bugfix on 0.2.5.2-alpha.
    - Improve the error message from ./configure to make it clear that
      when asciidoc has not been found, the user will have to either add
      --disable-asciidoc argument or install asciidoc. Resolves
      ticket 13228.

  o Code simplification and refactoring:
    - Change the entry_is_live() function to take named bitfield
      elements instead of an unnamed list of booleans. Closes
      ticket 12202.
    - Refactor and unit-test entry_is_time_to_retry() in entrynodes.c.
      Resolves ticket 12205.
    - Use calloc and reallocarray functions instead of multiply-
      then-malloc. This makes it less likely for us to fall victim to an
      integer overflow attack when allocating. Resolves ticket 12855.
    - Use the standard macro name SIZE_MAX, instead of our
      own SIZE_T_MAX.
    - Document usage of the NO_DIRINFO and ALL_DIRINFO flags clearly in
      functions which take them as arguments. Replace 0 with NO_DIRINFO
      in a function call for clarity. Seeks to prevent future issues
      like 13163.
    - Avoid 4 null pointer errors under clang static analysis by using
      tor_assert() to prove that the pointers aren't null. Fixes
      bug 13284.
    - Rework the API of policies_parse_exit_policy() to use a bitmask to
      represent parsing options, instead of a confusing mess of
      booleans. Resolves ticket 8197.
    - Introduce a helper function to parse ExitPolicy in
      or_options_t structure.

  o Documentation:
    - Add a doc/TUNING document with tips for handling large numbers of
      TCP connections when running busy Tor relay. Update the warning
      message to point to this file when running out of sockets
      operating system is allowing to use simultaneously. Resolves
      ticket 9708.

  o Removed features:
    - We no longer remind the user about configuration options that have
      been obsolete since 0.2.3.x or earlier. Patch by Adrien Bak.
    - Remove our old, non-weighted bandwidth-based node selection code.
      Previously, we used it as a fallback when we couldn't perform
      weighted bandwidth-based node selection. But that would only
      happen in the cases where we had no consensus, or when we had a
      consensus generated by buggy or ancient directory authorities. In
      either case, it's better to use the more modern, better maintained
      algorithm, with reasonable defaults for the weights. Closes
      ticket 13126.
    - Remove the --disable-curve25519 configure option. Relays and
      clients now are required to support curve25519 and the
      ntor handshake.
    - The old "StrictEntryNodes" and "StrictExitNodes" options, which
      used to be deprecated synonyms for "StrictNodes", are now marked
      obsolete. Resolves ticket 12226.
    - Clients don't understand the BadDirectory flag in the consensus
      anymore, and ignore it.

  o Testing:
    - Refactor the function that chooses guard nodes so that it can more
      easily be tested; write some tests for it.
    - Fix and re-enable the fgets_eagain unit test. Fixes bug 12503;
      bugfix on 0.2.3.1-alpha. Patch from "cypherpunks."
    - Create unit tests for format_time_interval(). With bug 13393.
    - Add unit tests for tor_timegm signed overflow, tor_timegm and
      parse_rfc1123_time validity checks, correct_tm year clamping. Unit
      tests (visible) fixes in bug 13476.
    - Add a "coverage-html" make target to generate HTML-visualized
      coverage results when building with --enable-coverage. (Requires
      lcov.) Patch from Kevin Murray.
    - Enable the backtrace handler (where supported) when running the
      unit tests.
    - Revise all unit tests that used the legacy test_* macros to
      instead use the recommended tt_* macros. This patch was generated
      with coccinelle, to avoid manual errors. Closes ticket 13119.

  o Distribution (systemd):
    - systemd unit file: only allow tor to write to /var/lib/tor and
      /var/log/tor. The rest of the filesystem is accessible for reading
      only. Patch by intrigeri; resolves ticket 12751.
    - systemd unit file: ensure that the process and all its children
      can never gain new privileges. Patch by intrigeri; resolves
      ticket 12939.
    - systemd unit file: set up /var/run/tor as writable for the Tor
      service. Patch by intrigeri; resolves ticket 13196.

  o Removed features (directory authorities):
    - Remove code that prevented authorities from listing Tor relays
      affected by CVE-2011-2769 as guards. These relays are already
      rejected altogether due to the minimum version requirement of
      0.2.3.16-alpha. Closes ticket 13152.
    - The "AuthDirRejectUnlisted" option no longer has any effect, as
      the fingerprints file (approved-routers) has been deprecated.
    - Directory authorities do not support being Naming dirauths anymore.
      The "NamingAuthoritativeDir" config option is now obsolete.
    - Directory authorities do not support giving out the BadDirectory
      flag anymore.
    - Directory authorities no longer advertise or support consensus
      methods 1 through 12 inclusive. These consensus methods were
      obsolete and/or insecure: maintaining the ability to support them
      served no good purpose. Implements part of proposal 215; closes
      ticket 10163.

  o Testing (test-network.sh):
    - Stop using "echo -n", as some shells' built-in echo doesn't
      support "-n". Instead, use "/bin/echo -n". Partially fixes
      bug 13161.
    - Stop an apparent test-network hang when used with make -j2. Fixes
      bug 13331.
    - Add a --delay option to test-network.sh, which configures the
      delay before the chutney network tests for data transmission.
      Partially implements ticket 13161.


Changes in version 0.2.5.10 - 2014-10-24
  Tor 0.2.5.10 is the first stable release in the 0.2.5 series.

  It adds several new security features, including improved
  denial-of-service resistance for relays, new compiler hardening
  options, and a system-call sandbox for hardened installations on Linux
  (requires seccomp2). The controller protocol has several new features,
  resolving IPv6 addresses should work better than before, and relays
  should be a little more CPU-efficient. We've added support for more
  OpenBSD and FreeBSD transparent proxy types. We've improved the build
  system and testing infrastructure to allow unit testing of more parts
  of the Tor codebase. Finally, we've addressed several nagging pluggable
  transport usability issues, and included numerous other small bugfixes
  and features mentioned below.

  This release marks end-of-life for Tor 0.2.3.x; those Tor versions
  have accumulated many known flaws; everyone should upgrade.

  o Deprecated versions:
    - Tor 0.2.3.x has reached end-of-life; it has received no patches or
      attention for some while.


Changes in version 0.2.5.9-rc - 2014-10-20
  Tor 0.2.5.9-rc is the third release candidate for the Tor 0.2.5.x
  series. It disables SSL3 in response to the recent "POODLE" attack
  (even though POODLE does not affect Tor). It also works around a crash
  bug caused by some operating systems' response to the "POODLE" attack
  (which does affect Tor). It also contains a few miscellaneous fixes.

  o Major security fixes:
    - Disable support for SSLv3. All versions of OpenSSL in use with Tor
      today support TLS 1.0 or later, so we can safely turn off support
      for this old (and insecure) protocol. Fixes bug 13426.

  o Major bugfixes (openssl bug workaround):
    - Avoid crashing when using OpenSSL version 0.9.8zc, 1.0.0o, or
      1.0.1j, built with the 'no-ssl3' configuration option. Fixes bug
      13471. This is a workaround for an OpenSSL bug.

  o Minor bugfixes:
    - Disable the sandbox name resolver cache when running tor-resolve:
      tor-resolve doesn't use the sandbox code, and turning it on was
      breaking attempts to do tor-resolve on a non-default server on
      Linux. Fixes bug 13295; bugfix on 0.2.5.3-alpha.

  o Compilation fixes:
    - Build and run correctly on systems like OpenBSD-current that have
      patched OpenSSL to remove get_cipher_by_char and/or its
      implementations. Fixes issue 13325.

  o Downgraded warnings:
    - Downgrade the severity of the 'unexpected sendme cell from client'
      from 'warn' to 'protocol warning'. Closes ticket 8093.


Changes in version 0.2.4.25 - 2014-10-20
  Tor 0.2.4.25 disables SSL3 in response to the recent "POODLE" attack
  (even though POODLE does not affect Tor). It also works around a crash
  bug caused by some operating systems' response to the "POODLE" attack
  (which does affect Tor).

  o Major security fixes (also in 0.2.5.9-rc):
    - Disable support for SSLv3. All versions of OpenSSL in use with Tor
      today support TLS 1.0 or later, so we can safely turn off support
      for this old (and insecure) protocol. Fixes bug 13426.

  o Major bugfixes (openssl bug workaround, also in 0.2.5.9-rc):
    - Avoid crashing when using OpenSSL version 0.9.8zc, 1.0.0o, or
      1.0.1j, built with the 'no-ssl3' configuration option. Fixes bug
      13471. This is a workaround for an OpenSSL bug.


Changes in version 0.2.5.8-rc - 2014-09-22
  Tor 0.2.5.8-rc is the second release candidate for the Tor 0.2.5.x
  series. It fixes a bug that affects consistency and speed when
  connecting to hidden services, and it updates the location of one of
  the directory authorities.

  o Major bugfixes:
    - Clients now send the correct address for their chosen rendezvous
      point when trying to access a hidden service. They used to send
      the wrong address, which would still work some of the time because
      they also sent the identity digest of the rendezvous point, and if
      the hidden service happened to try connecting to the rendezvous
      point from a relay that already had a connection open to it,
      the relay would reuse that connection. Now connections to hidden
      services should be more robust and faster. Also, this bug meant
      that clients were leaking to the hidden service whether they were
      on a little-endian (common) or big-endian (rare) system, which for
      some users might have reduced their anonymity. Fixes bug 13151;
      bugfix on 0.2.1.5-alpha.

  o Directory authority changes:
    - Change IP address for gabelmoo (v3 directory authority).


Changes in version 0.2.4.24 - 2014-09-22
  Tor 0.2.4.24 fixes a bug that affects consistency and speed when
  connecting to hidden services, and it updates the location of one of
  the directory authorities.

  o Major bugfixes:
    - Clients now send the correct address for their chosen rendezvous
      point when trying to access a hidden service. They used to send
      the wrong address, which would still work some of the time because
      they also sent the identity digest of the rendezvous point, and if
      the hidden service happened to try connecting to the rendezvous
      point from a relay that already had a connection open to it,
      the relay would reuse that connection. Now connections to hidden
      services should be more robust and faster. Also, this bug meant
      that clients were leaking to the hidden service whether they were
      on a little-endian (common) or big-endian (rare) system, which for
      some users might have reduced their anonymity. Fixes bug 13151;
      bugfix on 0.2.1.5-alpha.

  o Directory authority changes:
    - Change IP address for gabelmoo (v3 directory authority).

  o Minor features (geoip):
    - Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2
      Country database.


Changes in version 0.2.5.7-rc - 2014-09-11
  Tor 0.2.5.7-rc fixes several regressions from earlier in the 0.2.5.x
  release series, and some long-standing bugs related to ORPort reachability
  testing and failure to send CREATE cells. It is the first release
  candidate for the Tor 0.2.5.x series.

  o Major bugfixes (client, startup):
    - Start making circuits as soon as DisabledNetwork is turned off.
      When Tor started with DisabledNetwork set, it would correctly
      conclude that it shouldn't build circuits, but it would mistakenly
      cache this conclusion, and continue believing it even when
      DisableNetwork is set to 0. Fixes the bug introduced by the fix
      for bug 11200; bugfix on 0.2.5.4-alpha.
    - Resume expanding abbreviations for command-line options. The fix
      for bug 4647 accidentally removed our hack from bug 586 that
      rewrote HashedControlPassword to __HashedControlSessionPassword
      when it appears on the commandline (which allowed the user to set
      her own HashedControlPassword in the torrc file while the
      controller generates a fresh session password for each run). Fixes
      bug 12948; bugfix on 0.2.5.1-alpha.
    - Warn about attempts to run hidden services and relays in the same
      process: that's probably not a good idea. Closes ticket 12908.

  o Major bugfixes (relay):
    - Avoid queuing or sending destroy cells for circuit ID zero when we
      fail to send a CREATE cell. Fixes bug 12848; bugfix on 0.0.8pre1.
      Found and fixed by "cypherpunks".
    - Fix ORPort reachability detection on relays running behind a
      proxy, by correctly updating the "local" mark on the controlling
      channel when changing the address of an or_connection_t after the
      handshake. Fixes bug 12160; bugfix on 0.2.4.4-alpha.

  o Minor features (bridge):
    - Add an ExtORPortCookieAuthFileGroupReadable option to make the
      cookie file for the ExtORPort g+r by default.

  o Minor features (geoip):
    - Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (logging):
    - Reduce the log severity of the "Pluggable transport proxy does not
      provide any needed transports and will not be launched." message,
      since Tor Browser includes several ClientTransportPlugin lines in
      its torrc-defaults file, leading every Tor Browser user who looks
      at her logs to see these notices and wonder if they're dangerous.
      Resolves bug 13124; bugfix on 0.2.5.3-alpha.
    - Downgrade "Unexpected onionskin length after decryption" warning
      to a protocol-warn, since there's nothing relay operators can do
      about a client that sends them a malformed create cell. Resolves
      bug 12996; bugfix on 0.0.6rc1.
    - Log more specific warnings when we get an ESTABLISH_RENDEZVOUS
      cell on a cannibalized or non-OR circuit. Resolves ticket 12997.
    - When logging information about an EXTEND2 or EXTENDED2 cell, log
      their names correctly. Fixes part of bug 12700; bugfix
      on 0.2.4.8-alpha.
    - When logging information about a relay cell whose command we don't
      recognize, log its command as an integer. Fixes part of bug 12700;
      bugfix on 0.2.1.10-alpha.
    - Escape all strings from the directory connection before logging
      them. Fixes bug 13071; bugfix on 0.1.1.15. Patch from "teor".

  o Minor bugfixes (controller):
    - Restore the functionality of CookieAuthFileGroupReadable. Fixes
      bug 12864; bugfix on 0.2.5.1-alpha.
    - Actually send TRANSPORT_LAUNCHED and HS_DESC events to
      controllers. Fixes bug 13085; bugfix on 0.2.5.1-alpha. Patch
      by "teor".

  o Minor bugfixes (compilation):
    - Fix compilation of test.h with MSVC. Patch from Gisle Vanem;
      bugfix on 0.2.5.5-alpha.
    - Make the nmake make files work again. Fixes bug 13081. Bugfix on
      0.2.5.1-alpha. Patch from "NewEraCracker".
    - In routerlist_assert_ok(), don't take the address of a
      routerinfo's cache_info member unless that routerinfo is non-NULL.
      Fixes bug 13096; bugfix on 0.1.1.9-alpha. Patch by "teor".
    - Fix a large number of false positive warnings from the clang
      analyzer static analysis tool. This should make real warnings
      easier for clang analyzer to find. Patch from "teor". Closes
      ticket 13036.

  o Distribution (systemd):
    - Verify configuration file via ExecStartPre in the systemd unit
      file. Patch from intrigeri; resolves ticket 12730.
    - Explicitly disable RunAsDaemon in the systemd unit file. Our
      current systemd unit uses "Type = simple", so systemd does not
      expect tor to fork. If the user has "RunAsDaemon 1" in their
      torrc, then things won't work as expected. This is e.g. the case
      on Debian (and derivatives), since there we pass "--defaults-torrc
      /usr/share/tor/tor-service-defaults-torrc" (that contains
      "RunAsDaemon 1") by default. Patch by intrigeri; resolves
      ticket 12731.

  o Documentation:
    - Adjust the URLs in the README to refer to the new locations of
      several documents on the website. Fixes bug 12830. Patch from
      Matt Pagan.
    - Document 'reject6' and 'accept6' ExitPolicy entries. Resolves
      ticket 12878.


Changes in version 0.2.5.6-alpha - 2014-07-28
  Tor 0.2.5.6-alpha brings us a big step closer to slowing down the
  risk from guard rotation, and fixes a variety of other issues to get
  us closer to a release candidate.

  o Major features (also in 0.2.4.23):
    - Make the number of entry guards configurable via a new
      NumEntryGuards consensus parameter, and the number of directory
      guards configurable via a new NumDirectoryGuards consensus
      parameter. Implements ticket 12688.

  o Major bugfixes (also in 0.2.4.23):
    - Fix a bug in the bounds-checking in the 32-bit curve25519-donna
      implementation that caused incorrect results on 32-bit
      implementations when certain malformed inputs were used along with
      a small class of private ntor keys. This bug does not currently
      appear to allow an attacker to learn private keys or impersonate a
      Tor server, but it could provide a means to distinguish 32-bit Tor
      implementations from 64-bit Tor implementations. Fixes bug 12694;
      bugfix on 0.2.4.8-alpha. Bug found by Robert Ransom; fix from
      Adam Langley.

  o Major bugfixes:
    - Perform circuit cleanup operations even when circuit
      construction operations are disabled (because the network is
      disabled, or because there isn't enough directory information).
      Previously, when we were not building predictive circuits, we
      were not closing expired circuits either. Fixes bug 8387; bugfix on
      0.1.1.11-alpha. This bug became visible in 0.2.4.10-alpha when we
      became more strict about when we have "enough directory information
      to build circuits".

  o Minor features:
    - Authorities now assign the Guard flag to the fastest 25% of the
      network (it used to be the fastest 50%). Also raise the consensus
      weight that guarantees the Guard flag from 250 to 2000. For the
      current network, this results in about 1100 guards, down from 2500.
      This step paves the way for moving the number of entry guards
      down to 1 (proposal 236) while still providing reasonable expected
      performance for most users. Implements ticket 12690.
    - Update geoip and geoip6 to the July 10 2014 Maxmind GeoLite2
      Country database.
    - Slightly enhance the diagnostic message for bug 12184.

  o Minor bugfixes (also in 0.2.4.23):
    - Warn and drop the circuit if we receive an inbound 'relay early'
      cell. Those used to be normal to receive on hidden service circuits
      due to bug 1038, but the buggy Tor versions are long gone from
      the network so we can afford to resume watching for them. Resolves
      the rest of bug 1038; bugfix on 0.2.1.19.
    - Correct a confusing error message when trying to extend a circuit
      via the control protocol but we don't know a descriptor or
      microdescriptor for one of the specified relays. Fixes bug 12718;
      bugfix on 0.2.3.1-alpha.

  o Minor bugfixes:
    - Fix compilation when building with bufferevents enabled. (This
      configuration is still not expected to work, however.)
      Fixes bugs 12438, 12474, 11578; bugfixes on 0.2.5.1-alpha and
      0.2.5.3-alpha. Patches from Anthony G. Basile and Sathyanarayanan
      Gunasekaran.
    - Compile correctly with builds and forks of OpenSSL (such as
      LibreSSL) that disable compression. Fixes bug 12602; bugfix on
      0.2.1.1-alpha. Patch from "dhill".


Changes in version 0.2.4.23 - 2014-07-28
  Tor 0.2.4.23 brings us a big step closer to slowing down the risk from
  guard rotation, and also backports several important fixes from the
  Tor 0.2.5 alpha release series.

  o Major features:
    - Clients now look at the "usecreatefast" consensus parameter to
      decide whether to use CREATE_FAST or CREATE cells for the first hop
      of their circuit. This approach can improve security on connections
      where Tor's circuit handshake is stronger than the available TLS
      connection security levels, but the tradeoff is more computational
      load on guard relays. Implements proposal 221. Resolves ticket 9386.
    - Make the number of entry guards configurable via a new
      NumEntryGuards consensus parameter, and the number of directory
      guards configurable via a new NumDirectoryGuards consensus
      parameter. Implements ticket 12688.

  o Major bugfixes:
    - Fix a bug in the bounds-checking in the 32-bit curve25519-donna
      implementation that caused incorrect results on 32-bit
      implementations when certain malformed inputs were used along with
      a small class of private ntor keys. This bug does not currently
      appear to allow an attacker to learn private keys or impersonate a
      Tor server, but it could provide a means to distinguish 32-bit Tor
      implementations from 64-bit Tor implementations. Fixes bug 12694;
      bugfix on 0.2.4.8-alpha. Bug found by Robert Ransom; fix from
      Adam Langley.

  o Minor bugfixes:
    - Warn and drop the circuit if we receive an inbound 'relay early'
      cell. Those used to be normal to receive on hidden service circuits
      due to bug 1038, but the buggy Tor versions are long gone from
      the network so we can afford to resume watching for them. Resolves
      the rest of bug 1038; bugfix on 0.2.1.19.
    - Correct a confusing error message when trying to extend a circuit
      via the control protocol but we don't know a descriptor or
      microdescriptor for one of the specified relays. Fixes bug 12718;
      bugfix on 0.2.3.1-alpha.
    - Avoid an illegal read from stack when initializing the TLS
      module using a version of OpenSSL without all of the ciphers
      used by the v2 link handshake. Fixes bug 12227; bugfix on
      0.2.4.8-alpha.  Found by "starlight".

  o Minor features:
    - Update geoip and geoip6 to the July 10 2014 Maxmind GeoLite2
      Country database.


Changes in version 0.2.5.5-alpha - 2014-06-18
  Tor 0.2.5.5-alpha fixes a wide variety of remaining issues in the Tor
  0.2.5.x release series, including a couple of DoS issues, some
  performance regressions, a large number of bugs affecting the Linux
  seccomp2 sandbox code, and various other bugfixes. It also adds
  diagnostic bugfixes for a few tricky issues that we're trying to
  track down.

  o Major features (security, traffic analysis resistance):
    - Several major improvements to the algorithm used to decide when to
      close TLS connections. Previous versions of Tor closed connections
      at a fixed interval after the last time a non-padding cell was
      sent over the connection, regardless of the target of the
      connection. Now, we randomize the intervals by adding up to 50% of
      their base value, we measure the length of time since connection
      last had at least one circuit, and we allow connections to known
      ORs to remain open a little longer (15 minutes instead of 3
      minutes minimum). These changes should improve Tor's resistance
      against some kinds of traffic analysis, and lower some overhead
      from needlessly closed connections. Fixes ticket 6799.
      Incidentally fixes ticket 12023; bugfix on 0.2.5.1-alpha.

  o Major bugfixes (security, OOM, new since 0.2.5.4-alpha, also in 0.2.4.22):
    - Fix a memory leak that could occur if a microdescriptor parse
      fails during the tokenizing step. This bug could enable a memory
      exhaustion attack by directory servers. Fixes bug 11649; bugfix
      on 0.2.2.6-alpha.

  o Major bugfixes (security, directory authorities):
    - Directory authorities now include a digest of each relay's
      identity key as a part of its microdescriptor.

      This is a workaround for bug 11743 (reported by "cypherpunks"),
      where Tor clients do not support receiving multiple
      microdescriptors with the same SHA256 digest in the same
      consensus. When clients receive a consensus like this, they only
      use one of the relays. Without this fix, a hostile relay could
      selectively disable some client use of target relays by
      constructing a router descriptor with a different identity and the
      same microdescriptor parameters and getting the authorities to
      list it in a microdescriptor consensus. This fix prevents an
      attacker from causing a microdescriptor collision, because the
      router's identity is not forgeable.

  o Major bugfixes (relay):
    - Use a direct dirport connection when uploading non-anonymous
      descriptors to the directory authorities. Previously, relays would
      incorrectly use tunnel connections under a fairly wide variety of
      circumstances. Fixes bug 11469; bugfix on 0.2.4.3-alpha.
    - When a circuit accidentally has the same circuit ID for its
      forward and reverse direction, correctly detect the direction of
      cells using that circuit. Previously, this bug made roughly one
      circuit in a million non-functional. Fixes bug 12195; this is a
      bugfix on every version of Tor.

  o Major bugfixes (client, pluggable transports):
    - When managing pluggable transports, use OS notification facilities
      to learn if they have crashed, and don't attempt to kill any
      process that has already exited. Fixes bug 8746; bugfix
      on 0.2.3.6-alpha.

  o Minor features (diagnostic):
    - When logging a warning because of bug 7164, additionally check the
      hash table for consistency (as proposed on ticket 11737). This may
      help diagnose bug 7164.
    - When we log a heartbeat, log how many one-hop circuits we have
      that are at least 30 minutes old, and log status information about
      a few of them. This is an attempt to track down bug 8387.
    - When encountering an unexpected CR while writing text to a file on
      Windows, log the name of the file. Should help diagnosing
      bug 11233.
    - Give more specific warnings when a client notices that an onion
      handshake has failed. Fixes ticket 9635.
    - Add significant new logging code to attempt to diagnose bug 12184,
      where relays seem to run out of available circuit IDs.
    - Improve the diagnostic log message for bug 8387 even further to
      try to improve our odds of figuring out why one-hop directory
      circuits sometimes do not get closed.

  o Minor features (security, memory management):
    - Memory allocation tricks (mempools and buffer freelists) are now
      disabled by default. You can turn them back on with
      --enable-mempools and --enable-buf-freelists respectively. We're
      disabling these features because malloc performance is good enough
      on most platforms, and a similar feature in OpenSSL exacerbated
      exploitation of the Heartbleed attack. Resolves ticket 11476.

  o Minor features (security):
    - Apply the secure SipHash-2-4 function to the hash table mapping
      circuit IDs and channels to circuits. We missed this one when we
      were converting all the other hash functions to use SipHash back
      in 0.2.5.3-alpha. Resolves ticket 11750.

  o Minor features (build):
    - The configure script has a --disable-seccomp option to turn off
      support for libseccomp on systems that have it, in case it (or
      Tor's use of it) is broken. Resolves ticket 11628.

  o Minor features (other):
    - Update geoip and geoip6 to the June 4 2014 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (security, new since 0.2.5.4-alpha, also in 0.2.4.22):
    - When running a hidden service, do not allow TunneledDirConns 0;
      this will keep the hidden service from running, and also
      make it publish its descriptors directly over HTTP. Fixes bug 10849;
      bugfix on 0.2.1.1-alpha.

  o Minor bugfixes (performance):
    - Avoid a bug where every successful connection made us recompute
      the flag telling us whether we have sufficient information to
      build circuits. Previously, we would forget our cached value
      whenever we successfully opened a channel (or marked a router as
      running or not running for any other reason), regardless of
      whether we had previously believed the router to be running. This
      forced us to run an expensive update operation far too often.
      Fixes bug 12170; bugfix on 0.1.2.1-alpha.
    - Avoid using tor_memeq() for checking relay cell integrity. This
      removes a possible performance bottleneck. Fixes part of bug
      12169; bugfix on 0.2.1.31.

  o Minor bugfixes (compilation):
    - Fix compilation of test_status.c when building with MVSC. Bugfix
      on 0.2.5.4-alpha. Patch from Gisle Vanem.
    - Resolve GCC complaints on OpenBSD about discarding constness in
      TO_{ORIGIN,OR}_CIRCUIT functions. Fixes part of bug 11633; bugfix
      on 0.1.1.23. Patch from Dana Koch.
    - Resolve clang complaints on OpenBSD with -Wshorten-64-to-32 due to
      treatment of long and time_t as comparable types. Fixes part of
      bug 11633. Patch from Dana Koch.
    - Make Tor compile correctly with --disable-buf-freelists. Fixes bug
      11623; bugfix on 0.2.5.3-alpha.
    - When deciding whether to build the 64-bit curve25519
      implementation, detect platforms where we can compile 128-bit
      arithmetic but cannot link it. Fixes bug 11729; bugfix on
      0.2.4.8-alpha. Patch from "conradev".
    - Fix compilation when DNS_CACHE_DEBUG is enabled. Fixes bug 11761;
      bugfix on 0.2.3.13-alpha. Found by "cypherpunks".
    - Fix compilation with dmalloc. Fixes bug 11605; bugfix
      on 0.2.4.10-alpha.

  o Minor bugfixes (Directory server):
    - When sending a compressed set of descriptors or microdescriptors,
      make sure to finalize the zlib stream. Previously, we would write
      all the compressed data, but if the last descriptor we wanted to
      send was missing or too old, we would not mark the stream as
      finished. This caused problems for decompression tools. Fixes bug
      11648; bugfix on 0.1.1.23.

  o Minor bugfixes (Linux seccomp sandbox):
    - Make the seccomp sandbox code compile under ARM Linux. Fixes bug
      11622; bugfix on 0.2.5.1-alpha.
    - Avoid crashing when re-opening listener ports with the seccomp
      sandbox active. Fixes bug 12115; bugfix on 0.2.5.1-alpha.
    - Avoid crashing with the seccomp sandbox enabled along with
      ConstrainedSockets. Fixes bug 12139; bugfix on 0.2.5.1-alpha.
    - When we receive a SIGHUP with the sandbox enabled, correctly
      support rotating our log files. Fixes bug 12032; bugfix
      on 0.2.5.1-alpha.
    - Avoid crash when running with sandboxing enabled and
      DirReqStatistics not disabled. Fixes bug 12035; bugfix
      on 0.2.5.1-alpha.
    - Fix a "BUG" warning when trying to write bridge-stats files with
      the Linux syscall sandbox filter enabled. Fixes bug 12041; bugfix
      on 0.2.5.1-alpha.
    - Prevent the sandbox from crashing on startup when run with the
      --enable-expensive-hardening configuration option. Fixes bug
      11477; bugfix on 0.2.5.4-alpha.
    - When running with DirPortFrontPage and sandboxing both enabled,
      reload the DirPortFrontPage correctly when restarting. Fixes bug
      12028; bugfix on 0.2.5.1-alpha.
    - Don't try to enable the sandbox when using the Tor binary to check
      its configuration, hash a passphrase, or so on. Doing so was
      crashing on startup for some users. Fixes bug 11609; bugfix
      on 0.2.5.1-alpha.
    - Avoid warnings when running with sandboxing and node statistics
      enabled at the same time. Fixes part of 12064; bugfix on
      0.2.5.1-alpha. Patch from Michael Wolf.
    - Avoid warnings when running with sandboxing enabled at the same
      time as cookie authentication, hidden services, or directory
      authority voting. Fixes part of 12064; bugfix on 0.2.5.1-alpha.
    - Do not allow options that require calls to exec to be enabled
      alongside the seccomp2 sandbox: they will inevitably crash. Fixes
      bug 12043; bugfix on 0.2.5.1-alpha.
    - Handle failures in getpwnam()/getpwuid() when running with the
      User option set and the Linux syscall sandbox enabled. Fixes bug
      11946; bugfix on 0.2.5.1-alpha.
    - Refactor the getaddrinfo workaround that the seccomp sandbox uses
      to avoid calling getaddrinfo() after installing the sandbox
      filters. Previously, it preloaded a cache with the IPv4 address
      for our hostname, and nothing else. Now, it loads the cache with
      every address that it used to initialize the Tor process. Fixes
      bug 11970; bugfix on 0.2.5.1-alpha.

  o Minor bugfixes (pluggable transports):
    - Enable the ExtORPortCookieAuthFile option, to allow changing the
      default location of the authentication token for the extended OR
      Port as used by sever-side pluggable transports. We had
      implemented this option before, but the code to make it settable
      had been omitted. Fixes bug 11635; bugfix on 0.2.5.1-alpha.
    - Avoid another 60-second delay when starting Tor in a pluggable-
      transport-using configuration when we already have cached
      descriptors for our bridges. Fixes bug 11965; bugfix
      on 0.2.3.6-alpha.

  o Minor bugfixes (client):
    - Avoid "Tried to open a socket with DisableNetwork set" warnings
      when starting a client with bridges configured and DisableNetwork
      set. (Tor launcher starts Tor with DisableNetwork set the first
      time it runs.) Fixes bug 10405; bugfix on 0.2.3.9-alpha.

  o Minor bugfixes (testing):
    - The Python parts of the test scripts now work on Python 3 as well
      as Python 2, so systems where '/usr/bin/python' is Python 3 will
      no longer have the tests break. Fixes bug 11608; bugfix
      on 0.2.5.2-alpha.
    - When looking for versions of python that we could run the tests
      with, check for "python2.7" and "python3.3"; previously we were
      only looking for "python", "python2", and "python3". Patch from
      Dana Koch. Fixes bug 11632; bugfix on 0.2.5.2-alpha.
    - Fix all valgrind warnings produced by the unit tests. There were
      over a thousand memory leak warnings previously, mostly produced
      by forgetting to free things in the unit test code. Fixes bug
      11618, bugfixes on many versions of Tor.

  o Minor bugfixes (tor-fw-helper):
    - Give a correct log message when tor-fw-helper fails to launch.
      (Previously, we would say something like "tor-fw-helper sent us a
      string we could not parse".) Fixes bug 9781; bugfix
      on 0.2.4.2-alpha.

  o Minor bugfixes (relay, threading):
    - Check return code on spawn_func() in cpuworker code, so that we
      don't think we've spawned a nonworking cpuworker and write junk to
      it forever. Fix related to bug 4345; bugfix on all released Tor
      versions. Found by "skruffy".
    - Use a pthread_attr to make sure that spawn_func() cannot return an
      error while at the same time launching a thread. Fix related to
      bug 4345; bugfix on all released Tor versions. Reported
      by "cypherpunks".

  o Minor bugfixes (relay, oom prevention):
    - Correctly detect the total available system memory. We tried to do
      this in 0.2.5.4-alpha, but the code was set up to always return an
      error value, even on success. Fixes bug 11805; bugfix
      on 0.2.5.4-alpha.

  o Minor bugfixes (relay, other):
    - We now drop CREATE cells for already-existent circuit IDs and for
      zero-valued circuit IDs, regardless of other factors that might
      otherwise have called for DESTROY cells. Fixes bug 12191; bugfix
      on 0.0.8pre1.
    - Avoid an illegal read from stack when initializing the TLS module
      using a version of OpenSSL without all of the ciphers used by the
      v2 link handshake. Fixes bug 12227; bugfix on 0.2.4.8-alpha. Found
      by "starlight".
    - When rejecting DATA cells for stream_id zero, still count them
      against the circuit's deliver window so that we don't fail to send
      a SENDME. Fixes bug 11246; bugfix on 0.2.4.10-alpha.

  o Minor bugfixes (logging):
    - Fix a misformatted log message about delayed directory fetches.
      Fixes bug 11654; bugfix on 0.2.5.3-alpha.
    - Squelch a spurious LD_BUG message "No origin circuit for
      successful SOCKS stream" in certain hidden service failure cases;
      fixes bug 10616.

  o Distribution:
    - Include a tor.service file in contrib/dist for use with systemd.
      Some distributions will be able to use this file unmodified;
      others will need to tweak it, or write their own. Patch from Jamie
      Nguyen; resolves ticket 8368.

  o Documentation:
    - Clean up several option names in the manpage to match their real
      names, add the missing documentation for a couple of testing and
      directory authority options, remove the documentation for a
      V2-directory fetching option that no longer exists. Resolves
      ticket 11634.
    - Correct the documenation so that it lists the correct directory
      for the stats files. (They are in a subdirectory called "stats",
      not "status".)
    - In the manpage, move more authority-only options into the
      directory authority section so that operators of regular directory
      caches don't get confused.

  o Package cleanup:
    - The contrib directory has been sorted and tidied. Before, it was
      an unsorted dumping ground for useful and not-so-useful things.
      Now, it is divided based on functionality, and the items which
      seemed to be nonfunctional or useless have been removed. Resolves
      ticket 8966; based on patches from "rl1987".

  o Removed code:
    - Remove /tor/dbg-stability.txt URL that was meant to help debug WFU
      and MTBF calculations, but that nobody was using. Fixes ticket 11742.
    - The TunnelDirConns and PreferTunnelledDirConns options no longer
      exist; tunneled directory connections have been available since
      0.1.2.5-alpha, and turning them off is not a good idea. This is a
      brute-force fix for 10849, where "TunnelDirConns 0" would break
      hidden services.


Changes in version 0.2.4.22 - 2014-05-16
  Tor 0.2.4.22 backports numerous high-priority fixes from the Tor 0.2.5
  alpha release series. These include blocking all authority signing
  keys that may have been affected by the OpenSSL "heartbleed" bug,
  choosing a far more secure set of TLS ciphersuites by default, closing
  a couple of memory leaks that could be used to run a target relay out
  of RAM, and several others.

  o Major features (security, backport from 0.2.5.4-alpha):
    - Block authority signing keys that were used on authorities
      vulnerable to the "heartbleed" bug in OpenSSL (CVE-2014-0160). (We
      don't have any evidence that these keys _were_ compromised; we're
      doing this to be prudent.) Resolves ticket 11464.

  o Major bugfixes (security, OOM):
    - Fix a memory leak that could occur if a microdescriptor parse
      fails during the tokenizing step. This bug could enable a memory
      exhaustion attack by directory servers. Fixes bug 11649; bugfix
      on 0.2.2.6-alpha.

  o Major bugfixes (TLS cipher selection, backport from 0.2.5.4-alpha):
    - The relay ciphersuite list is now generated automatically based on
      uniform criteria, and includes all OpenSSL ciphersuites with
      acceptable strength and forward secrecy. Previously, we had left
      some perfectly fine ciphersuites unsupported due to omission or
      typo. Resolves bugs 11513, 11492, 11498, 11499. Bugs reported by
      'cypherpunks'. Bugfix on 0.2.4.8-alpha.
    - Relays now trust themselves to have a better view than clients of
      which TLS ciphersuites are better than others. (Thanks to bug
      11513, the relay list is now well-considered, whereas the client
      list has been chosen mainly for anti-fingerprinting purposes.)
      Relays prefer: AES over 3DES; then ECDHE over DHE; then GCM over
      CBC; then SHA384 over SHA256 over SHA1; and last, AES256 over
      AES128. Resolves ticket 11528.
    - Clients now try to advertise the same list of ciphersuites as
      Firefox 28. This change enables selection of (fast) GCM
      ciphersuites, disables some strange old ciphers, and stops
      advertising the ECDH (not to be confused with ECDHE) ciphersuites.
      Resolves ticket 11438.

  o Minor bugfixes (configuration, security):
    - When running a hidden service, do not allow TunneledDirConns 0:
      trying to set that option together with a hidden service would
      otherwise prevent the hidden service from running, and also make
      it publish its descriptors directly over HTTP. Fixes bug 10849;
      bugfix on 0.2.1.1-alpha.

  o Minor bugfixes (controller, backport from 0.2.5.4-alpha):
    - Avoid sending a garbage value to the controller when a circuit is
      cannibalized. Fixes bug 11519; bugfix on 0.2.3.11-alpha.

  o Minor bugfixes (exit relay, backport from 0.2.5.4-alpha):
    - Stop leaking memory when we successfully resolve a PTR record.
      Fixes bug 11437; bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (bridge client, backport from 0.2.5.4-alpha):
    - Avoid 60-second delays in the bootstrapping process when Tor is
      launching for a second time while using bridges. Fixes bug 9229;
      bugfix on 0.2.0.3-alpha.

  o Minor bugfixes (relays and bridges, backport from 0.2.5.4-alpha):
    - Give the correct URL in the warning message when trying to run a
      relay on an ancient version of Windows. Fixes bug 9393.

  o Minor bugfixes (compilation):
    - Fix a compilation error when compiling with --disable-curve25519.
      Fixes bug 9700; bugfix on 0.2.4.17-rc.

  o Minor bugfixes:
    - Downgrade the warning severity for the the "md was still
      referenced 1 node(s)" warning. Tor 0.2.5.4-alpha has better code
      for trying to diagnose this bug, and the current warning in
      earlier versions of tor achieves nothing useful. Addresses warning
      from bug 7164.

  o Minor features (log verbosity, backport from 0.2.5.4-alpha):
    - When we run out of usable circuit IDs on a channel, log only one
      warning for the whole channel, and describe how many circuits
      there were on the channel. Fixes part of ticket 11553.

  o Minor features (security, backport from 0.2.5.4-alpha):
    - Decrease the lower limit of MaxMemInCellQueues to 256 MBytes (but
      leave the default at 8GBytes), to better support Raspberry Pi
      users. Fixes bug 9686; bugfix on 0.2.4.14-alpha.

  o Documentation (backport from 0.2.5.4-alpha):
    - Correctly document that we search for a system torrc file before
      looking in ~/.torrc. Fixes documentation side of 9213; bugfix on
      0.2.3.18-rc.


Changes in version 0.2.5.4-alpha - 2014-04-25
  Tor 0.2.5.4-alpha includes several security and performance
  improvements for clients and relays, including blacklisting authority
  signing keys that were used while susceptible to the OpenSSL
  "heartbleed" bug, fixing two expensive functions on busy relays,
  improved TLS ciphersuite preference lists, support for run-time
  hardening on compilers that support AddressSanitizer, and more work on
  the Linux sandbox code.

  There are also several usability fixes for clients (especially clients
  that use bridges), two new TransPort protocols supported (one on
  OpenBSD, one on FreeBSD), and various other bugfixes.

  This release marks end-of-life for Tor 0.2.2.x; those Tor versions
  have accumulated many known flaws; everyone should upgrade.

  o Major features (security):
    - If you don't specify MaxMemInQueues yourself, Tor now tries to
      pick a good value based on your total system memory. Previously,
      the default was always 8 GB. You can still override the default by
      setting MaxMemInQueues yourself. Resolves ticket 11396.
    - Block authority signing keys that were used on authorities
      vulnerable to the "heartbleed" bug in OpenSSL (CVE-2014-0160). (We
      don't have any evidence that these keys _were_ compromised; we're
      doing this to be prudent.) Resolves ticket 11464.

  o Major features (relay performance):
    - Speed up server-side lookups of rendezvous and introduction point
      circuits by using hashtables instead of linear searches. These
      functions previously accounted between 3 and 7% of CPU usage on
      some busy relays. Resolves ticket 9841.
    - Avoid wasting CPU when extending a circuit over a channel that is
      nearly out of circuit IDs. Previously, we would do a linear scan
      over possible circuit IDs before finding one or deciding that we
      had exhausted our possibilities. Now, we try at most 64 random
      circuit IDs before deciding that we probably won't succeed. Fixes
      a possible root cause of ticket 11553.

  o Major features (seccomp2 sandbox, Linux only):
    - The seccomp2 sandbox can now run a test network for multiple hours
      without crashing. The sandbox is still experimental, and more bugs
      will probably turn up. To try it, enable "Sandbox 1" on a Linux
      host. Resolves ticket 11351.
    - Strengthen sandbox code: the sandbox can now test the arguments
      for rename(), and blocks _sysctl() entirely. Resolves another part
      of ticket 11351.
    - When the sandbox blocks a system call, it now tries to log a stack
      trace before exiting. Resolves ticket 11465.

  o Major bugfixes (TLS cipher selection):
    - The relay ciphersuite list is now generated automatically based on
      uniform criteria, and includes all OpenSSL ciphersuites with
      acceptable strength and forward secrecy. Previously, we had left
      some perfectly fine ciphersuites unsupported due to omission or
      typo. Resolves bugs 11513, 11492, 11498, 11499. Bugs reported by
      'cypherpunks'. Bugfix on 0.2.4.8-alpha.
    - Relays now trust themselves to have a better view than clients of
      which TLS ciphersuites are better than others. (Thanks to bug
      11513, the relay list is now well-considered, whereas the client
      list has been chosen mainly for anti-fingerprinting purposes.)
      Relays prefer: AES over 3DES; then ECDHE over DHE; then GCM over
      CBC; then SHA384 over SHA256 over SHA1; and last, AES256 over
      AES128. Resolves ticket 11528.
    - Clients now try to advertise the same list of ciphersuites as
      Firefox 28. This change enables selection of (fast) GCM
      ciphersuites, disables some strange old ciphers, and stops
      advertising the ECDH (not to be confused with ECDHE) ciphersuites.
      Resolves ticket 11438.

  o Major bugfixes (bridge client):
    - Avoid 60-second delays in the bootstrapping process when Tor is
      launching for a second time while using bridges. Fixes bug 9229;
      bugfix on 0.2.0.3-alpha.

  o Minor features (transparent proxy, *BSD):
    - Support FreeBSD's ipfw firewall interface for TransPort ports on
      FreeBSD. To enable it, set "TransProxyType ipfw". Resolves ticket
      10267; patch from "yurivict".
    - Support OpenBSD's divert-to rules with the pf firewall for
      transparent proxy ports. To enable it, set "TransProxyType
      pf-divert". This allows Tor to run a TransPort transparent proxy
      port on OpenBSD 4.4 or later without root privileges. See the
      pf.conf(5) manual page for information on configuring pf to use
      divert-to rules. Closes ticket 10896; patch from Dana Koch.

  o Minor features (security):
    - New --enable-expensive-hardening option to enable security
      hardening options that consume nontrivial amounts of CPU and
      memory. Right now, this includes AddressSanitizer and UbSan, which
      are supported in newer versions of GCC and Clang. Closes ticket
      11477.

  o Minor features (log verbosity):
    - Demote the message that we give when a flushing connection times
      out for too long from NOTICE to INFO. It was usually meaningless.
      Resolves ticket 5286.
    - Don't log so many notice-level bootstrapping messages at startup
      about downloading descriptors. Previously, we'd log a notice
      whenever we learned about more routers. Now, we only log a notice
      at every 5% of progress. Fixes bug 9963.
    - Warn less verbosely when receiving a malformed
      ESTABLISH_RENDEZVOUS cell. Fixes ticket 11279.
    - When we run out of usable circuit IDs on a channel, log only one
      warning for the whole channel, and describe how many circuits
      there were on the channel. Fixes part of ticket 11553.

  o Minor features (relay):
    - If a circuit timed out for at least 3 minutes, check if we have a
      new external IP address, and publish a new descriptor with the new
      IP address if it changed. Resolves ticket 2454.

  o Minor features (controller):
    - Make the entire exit policy available from the control port via
      GETINFO exit-policy/*. Implements enhancement 7952. Patch from
      "rl1987".
    - Because of the fix for ticket 11396, the real limit for memory
      usage may no longer match the configured MaxMemInQueues value. The
      real limit is now exposed via GETINFO limits/max-mem-in-queues.

  o Minor features (bridge client):
    - Report a more useful failure message when we can't connect to a
      bridge because we don't have the right pluggable transport
      configured. Resolves ticket 9665. Patch from Fábio J. Bertinatto.

  o Minor features (diagnostic):
    - Add more log messages to diagnose bug 7164, which causes
      intermittent "microdesc_free() called but md was still referenced"
      warnings. We now include more information, to figure out why we
      might be cleaning a microdescriptor for being too old if it's
      still referenced by a live node_t object.

  o Minor bugfixes (client, DNSPort):
    - When using DNSPort, try to respond to AAAA requests with AAAA
      answers. Previously, we hadn't looked at the request type when
      deciding which answer type to prefer. Fixes bug 10468; bugfix on
      0.2.4.7-alpha.
    - When receiving a DNS query for an unsupported record type, reply
      with no answer rather than with a NOTIMPL error. This behavior
      isn't correct either, but it will break fewer client programs, we
      hope. Fixes bug 10268; bugfix on 0.2.0.1-alpha. Original patch
      from "epoch".

  o Minor bugfixes (exit relay):
    - Stop leaking memory when we successfully resolve a PTR record.
      Fixes bug 11437; bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (bridge client):
    - Stop accepting bridge lines containing hostnames. Doing so would
      cause clients to perform DNS requests on the hostnames, which was
      not sensible behavior. Fixes bug 10801; bugfix on 0.2.0.1-alpha.
    - Avoid a 60-second delay in the bootstrapping process when a Tor
      client with pluggable transports re-reads its configuration at
      just the wrong time. Re-fixes bug 11156; bugfix on 0.2.5.3-alpha.

  o Minor bugfixes (client, logging during bootstrap):
    - Warn only once if we start logging in an unsafe way. Previously,
      we complain as many times as we had problems. Fixes bug 9870;
      bugfix on 0.2.5.1-alpha.
    - Only report the first fatal bootstrap error on a given OR
      connection. This stops us from telling the controller bogus error
      messages like "DONE". Fixes bug 10431; bugfix on 0.2.1.1-alpha.
    - Be more helpful when trying to run sandboxed on Linux without
      libseccomp. Instead of saying "Sandbox is not implemented on this
      platform", we now explain that we need to be built with
      libseccomp. Fixes bug 11543; bugfix on 0.2.5.1-alpha.
    - Avoid generating spurious warnings when starting with
      DisableNetwork enabled. Fixes bug 11200 and bug 10405; bugfix on
      0.2.3.9-alpha.

  o Minor bugfixes (closing OR connections):
    - If write_to_buf() in connection_write_to_buf_impl_() ever fails,
      check if it's an or_connection_t and correctly call
      connection_or_close_for_error() rather than
      connection_mark_for_close() directly. Fixes bug 11304; bugfix on
      0.2.4.4-alpha.
    - When closing all connections on setting DisableNetwork to 1, use
      connection_or_close_normally() rather than closing OR connections
      out from under the channel layer. Fixes bug 11306; bugfix on
      0.2.4.4-alpha.

  o Minor bugfixes (controller):
    - Avoid sending a garbage value to the controller when a circuit is
      cannibalized. Fixes bug 11519; bugfix on 0.2.3.11-alpha.

  o Minor bugfixes (tor-fw-helper):
    - Allow tor-fw-helper to build again by adding src/ext to its
      CPPFLAGS. Fixes bug 11296; bugfix on 0.2.5.3-alpha.

  o Minor bugfixes (bridges):
    - Avoid potential crashes or bad behavior when launching a
      server-side managed proxy with ORPort or ExtORPort temporarily
      disabled. Fixes bug 9650; bugfix on 0.2.3.16-alpha.

  o Minor bugfixes (platform-specific):
    - Fix compilation on Solaris, which does not have <endian.h>. Fixes
      bug 11426; bugfix on 0.2.5.3-alpha.
    - When dumping a malformed directory object to disk, save it in
      binary mode on Windows, not text mode. Fixes bug 11342; bugfix on
      0.2.2.1-alpha.
    - Don't report failures from make_socket_reuseable() on incoming
      sockets on OSX: this can happen when incoming connections close
      early. Fixes bug 10081.

  o Minor bugfixes (trivial memory leaks):
    - Fix a small memory leak when signing a directory object. Fixes bug
      11275; bugfix on 0.2.4.13-alpha.
    - Free placeholder entries in our circuit table at exit; fixes a
      harmless memory leak. Fixes bug 11278; bugfix on 0.2.5.1-alpha.
    - Don't re-initialize a second set of OpenSSL mutexes when starting
      up. Previously, we'd make one set of mutexes, and then immediately
      replace them with another. Fixes bug 11726; bugfix on
      0.2.5.3-alpha.
    - Resolve some memory leaks found by coverity in the unit tests, on
      exit in tor-gencert, and on a failure to compute digests for our
      own keys when generating a v3 networkstatus vote. These leaks
      should never have affected anyone in practice.

  o Minor bugfixes (hidden service):
    - Only retry attempts to connect to a chosen rendezvous point 8
      times, not 30. Fixes bug 4241; bugfix on 0.1.0.1-rc.

  o Minor bugfixes (misc code correctness):
    - Fix various instances of undefined behavior in channeltls.c,
      tor_memmem(), and eventdns.c that would cause us to construct
      pointers to memory outside an allocated object. (These invalid
      pointers were not accessed, but C does not even allow them to
      exist.) Fixes bug 10363; bugfixes on 0.1.1.1-alpha, 0.1.2.1-alpha,
      0.2.0.10-alpha, and 0.2.3.6-alpha. Reported by "bobnomnom".
    - Use the AddressSanitizer and Ubsan sanitizers (in clang-3.4) to
      fix some miscellaneous errors in our tests and codebase. Fixes bug
      11232. Bugfixes on versions back as far as 0.2.1.11-alpha.
    - Always check return values for unlink, munmap, UnmapViewOfFile;
      check strftime return values more often. In some cases all we can
      do is report a warning, but this may help prevent deeper bugs from
      going unnoticed. Closes ticket 8787; bugfixes on many, many tor
      versions.
    - Fix numerous warnings from the clang "scan-build" static analyzer.
      Some of these are programming style issues; some of them are false
      positives that indicated awkward code; some are undefined behavior
      cases related to constructing (but not using) invalid pointers;
      some are assumptions about API behavior; some are (harmlessly)
      logging sizeof(ptr) bytes from a token when sizeof(*ptr) would be
      correct; and one or two are genuine bugs that weren't reachable
      from the rest of the program. Fixes bug 8793; bugfixes on many,
      many tor versions.

  o Documentation:
    - Build the torify.1 manpage again. Previously, we were only trying
      to build it when also building tor-fw-helper. That's why we didn't
      notice that we'd broken the ability to build it. Fixes bug 11321;
      bugfix on 0.2.5.1-alpha.
    - Fix the layout of the SOCKSPort flags in the manpage. Fixes bug
      11061; bugfix on 0.2.4.7-alpha.
    - Correctly document that we search for a system torrc file before
      looking in ~/.torrc. Fixes documentation side of 9213; bugfix on
      0.2.3.18-rc.
    - Resolve warnings from Doxygen.

  o Code simplifications and refactoring:
    - Remove is_internal_IP() function. Resolves ticket 4645.
    - Remove unused function circuit_dump_by_chan from circuitlist.c.
      Closes issue 9107; patch from "marek".
    - Change our use of the ENUM_BF macro to avoid declarations that
      confuse Doxygen.

  o Deprecated versions:
    - Tor 0.2.2.x has reached end-of-life; it has received no patches or
      attention for some while. Directory authorities no longer accept
      descriptors from relays running any version of Tor prior to Tor
      0.2.3.16-alpha. Resolves ticket 11149.

  o Testing:
    - New macros in test.h to simplify writing mock-functions for unit
      tests. Part of ticket 11507. Patch from Dana Koch.
    - Complete tests for the status.c module. Resolves ticket 11507.
      Patch from Dana Koch.

  o Removed code:
    - Remove all code for the long unused v1 directory protocol.
      Resolves ticket 11070.


Changes in version 0.2.5.3-alpha - 2014-03-22
  Tor 0.2.5.3-alpha includes all the fixes from 0.2.4.21. It contains
  two new anti-DoS features for Tor relays, resolves a bug that kept
  SOCKS5 support for IPv6 from working, fixes several annoying usability
  issues for bridge users, and removes more old code for unused
  directory formats.

  The Tor 0.2.5.x release series is now in patch-freeze: no feature
  patches not already written will be considered for inclusion in 0.2.5.x.

  o Major features (relay security, DoS-resistance):
    - When deciding whether we have run out of memory and we need to
      close circuits, also consider memory allocated in buffers for
      streams attached to each circuit.

      This change, which extends an anti-DoS feature introduced in
      0.2.4.13-alpha and improved in 0.2.4.14-alpha, lets Tor exit relays
      better resist more memory-based DoS attacks than before. Since the
      MaxMemInCellQueues option now applies to all queues, it is renamed
      to MaxMemInQueues. This feature fixes bug 10169.
    - Avoid hash-flooding denial-of-service attacks by using the secure
      SipHash-2-4 hash function for our hashtables. Without this
      feature, an attacker could degrade performance of a targeted
      client or server by flooding their data structures with a large
      number of entries to be stored at the same hash table position,
      thereby slowing down the Tor instance. With this feature, hash
      table positions are derived from a randomized cryptographic key,
      and an attacker cannot predict which entries will collide. Closes
      ticket 4900.
    - Decrease the lower limit of MaxMemInQueues to 256 MBytes (but leave
      the default at 8GBytes), to better support Raspberry Pi users. Fixes
      bug 9686; bugfix on 0.2.4.14-alpha.

  o Minor features (bridges, pluggable transports):
    - Bridges now write the SHA1 digest of their identity key
      fingerprint (that is, a hash of a hash of their public key) to
      notice-level logs, and to a new hashed-fingerprint file. This
      information will help bridge operators look up their bridge in
      Globe and similar tools. Resolves ticket 10884.
    - Improve the message that Tor displays when running as a bridge
      using pluggable transports without an Extended ORPort listener.
      Also, log the message in the log file too. Resolves ticket 11043.

  o Minor features (other):
    - Add a new option, PredictedPortsRelevanceTime, to control how long
      after having received a request to connect to a given port Tor
      will try to keep circuits ready in anticipation of future requests
      for that port. Patch from "unixninja92"; implements ticket 9176.
    - Generate a warning if any ports are listed in the SocksPolicy,
      DirPolicy, AuthDirReject, AuthDirInvalid, AuthDirBadDir, or
      AuthDirBadExit options. (These options only support address
      ranges.) Fixes part of ticket 11108.
    - Update geoip and geoip6 to the February 7 2014 Maxmind GeoLite2
      Country database.

  o Minor bugfixes (new since 0.2.5.2-alpha, also in 0.2.4.21):
    - Build without warnings under clang 3.4. (We have some macros that
      define static functions only some of which will get used later in
      the module. Starting with clang 3.4, these give a warning unless the
      unused attribute is set on them.) Resolves ticket 10904.
    - Fix build warnings about missing "a2x" comment when building the
      manpages from scratch on OpenBSD; OpenBSD calls it "a2x.py".
      Fixes bug 10929; bugfix on 0.2.2.9-alpha. Patch from Dana Koch.

  o Minor bugfixes (client):
    - Improve the log message when we can't connect to a hidden service
      because all of the hidden service directory nodes hosting its
      descriptor are excluded. Improves on our fix for bug 10722, which
      was a bugfix on 0.2.0.10-alpha.
    - Raise a control port warning when we fail to connect to all of
      our bridges. Previously, we didn't inform the controller, and
      the bootstrap process would stall. Fixes bug 11069; bugfix on
      0.2.1.2-alpha.
    - Exit immediately when a process-owning controller exits.
      Previously, tor relays would wait for a little while after their
      controller exited, as if they had gotten an INT signal -- but this
      was problematic, since there was no feedback for the user. To do a
      clean shutdown, controllers should send an INT signal and give Tor
      a chance to clean up. Fixes bug 10449; bugfix on 0.2.2.28-beta.
    - Stop attempting to connect to bridges before our pluggable
      transports are configured (harmless but resulted in some erroneous
      log messages). Fixes bug 11156; bugfix on 0.2.3.2-alpha.
    - Fix connections to IPv6 addresses over SOCKS5. Previously, we were
      generating incorrect SOCKS5 responses, and confusing client
      applications. Fixes bug 10987; bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (relays and bridges):
    - Avoid crashing on a malformed resolv.conf file when running a
      relay using Libevent 1. Fixes bug 8788; bugfix on 0.1.1.23.
    - Non-exit relays no longer launch mock DNS requests to check for
      DNS hijacking. This has been unnecessary since 0.2.1.7-alpha, when
      non-exit relays stopped servicing DNS requests. Fixes bug 965;
      bugfix on 0.2.1.7-alpha. Patch from Matt Pagan.
    - Bridges now report complete directory request statistics. Related
      to bug 5824; bugfix on 0.2.2.1-alpha.
    - Bridges now never collect statistics that were designed for
      relays. Fixes bug 5824; bugfix on 0.2.3.8-alpha.
    - Stop giving annoying warning messages when we decide not to launch
      a pluggable transport proxy that we don't need (because there are
      no bridges configured to use it). Resolves ticket 5018; bugfix
      on 0.2.5.2-alpha.
    - Give the correct URL in the warning message when trying to run a
      relay on an ancient version of Windows. Fixes bug 9393.

  o Minor bugfixes (backtrace support):
    - Support automatic backtraces on more platforms by using the
      "-fasynchronous-unwind-tables" compiler option. This option is
      needed for platforms like 32-bit Intel where "-fomit-frame-pointer"
      is on by default and table generation is not. This doesn't yet
      add Windows support; only Linux, OSX, and some BSDs are affected.
      Reported by 'cypherpunks'; fixes bug 11047; bugfix on 0.2.5.2-alpha.
    - Avoid strange behavior if two threads hit failed assertions at the
      same time and both try to log backtraces at once. (Previously, if
      this had happened, both threads would have stored their intermediate
      results in the same buffer, and generated junk outputs.) Reported by
      "cypherpunks". Fixes bug 11048; bugfix on 0.2.5.2-alpha.
    - Fix a compiler warning in format_number_sigsafe(). Bugfix on
      0.2.5.2-alpha; patch from Nick Hopper.

  o Minor bugfixes (unit tests):
    - Fix a small bug in the unit tests that might have made the tests
      call 'chmod' with an uninitialized bitmask. Fixes bug 10928;
      bugfix on 0.2.5.1-alpha. Patch from Dana Koch.

  o Removed code:
    - Remove all remaining code related to version-0 hidden service
      descriptors: they have not been in use since 0.2.2.1-alpha. Fixes
      the rest of bug 10841.

  o Documentation:
    - Document in the manpage that "KBytes" may also be written as
      "kilobytes" or "KB", that "Kbits" may also be written as
      "kilobits", and so forth. Closes ticket 9222.
    - Document that the ClientOnly config option overrides ORPort.
      Our old explanation made ClientOnly sound as though it did
      nothing at all. Resolves bug 9059.
    - Explain that SocksPolicy, DirPolicy, and similar options don't
      take port arguments. Fixes the other part of ticket 11108.
    - Fix a comment about the rend_server_descriptor_t.protocols field
      to more accurately describe its range. Also, make that field
      unsigned, to more accurately reflect its usage. Fixes bug 9099;
      bugfix on 0.2.1.5-alpha.
    - Fix the manpage's description of HiddenServiceAuthorizeClient:
      the maximum client name length is 16, not 19. Fixes bug 11118;
      bugfix on 0.2.1.6-alpha.

  o Code simplifications and refactoring:
    - Get rid of router->address, since in all cases it was just the
      string representation of router->addr. Resolves ticket 5528.

  o Test infrastructure:
    - Update to the latest version of tinytest.
    - Improve the tinytest implementation of string operation tests so
      that comparisons with NULL strings no longer crash the tests; they
      now just fail, normally. Fixes bug 9004; bugfix on 0.2.2.4-alpha.


Changes in version 0.2.4.21 - 2014-02-28
  Tor 0.2.4.21 further improves security against potential adversaries who
  find breaking 1024-bit crypto doable, and backports several stability
  and robustness patches from the 0.2.5 branch.

  o Major features (client security):
    - When we choose a path for a 3-hop circuit, make sure it contains
      at least one relay that supports the NTor circuit extension
      handshake. Otherwise, there is a chance that we're building
      a circuit that's worth attacking by an adversary who finds
      breaking 1024-bit crypto doable, and that chance changes the game
      theory. Implements ticket 9777.

  o Major bugfixes:
    - Do not treat streams that fail with reason
      END_STREAM_REASON_INTERNAL as indicating a definite circuit failure,
      since it could also indicate an ENETUNREACH connection error. Fixes
      part of bug 10777; bugfix on 0.2.4.8-alpha.

  o Code simplification and refactoring:
    - Remove data structures which were introduced to implement the
      CellStatistics option: they are now redundant with the new timestamp
      field in the regular packed_cell_t data structure, which we did
      in 0.2.4.18-rc in order to resolve bug 9093. Resolves ticket 10870.

  o Minor features:
    - Always clear OpenSSL bignums before freeing them -- even bignums
      that don't contain secrets. Resolves ticket 10793. Patch by
      Florent Daigniere.
    - Build without warnings under clang 3.4. (We have some macros that
      define static functions only some of which will get used later in
      the module. Starting with clang 3.4, these give a warning unless the
      unused attribute is set on them.) Resolves ticket 10904.
    - Update geoip and geoip6 files to the February 7 2014 Maxmind
      GeoLite2 Country database.

  o Minor bugfixes:
    - Set the listen() backlog limit to the largest actually supported
      on the system, not to the value in a header file. Fixes bug 9716;
      bugfix on every released Tor.
    - Treat ENETUNREACH, EACCES, and EPERM connection failures at an
      exit node as a NOROUTE error, not an INTERNAL error, since they
      can apparently happen when trying to connect to the wrong sort
      of netblocks. Fixes part of bug 10777; bugfix on 0.1.0.1-rc.
    - Fix build warnings about missing "a2x" comment when building the
      manpages from scratch on OpenBSD; OpenBSD calls it "a2x.py".
      Fixes bug 10929; bugfix on 0.2.2.9-alpha. Patch from Dana Koch.
    - Avoid a segfault on SIGUSR1, where we had freed a connection but did
      not entirely remove it from the connection lists. Fixes bug 9602;
      bugfix on 0.2.4.4-alpha.
    - Fix a segmentation fault in our benchmark code when running with
      Fedora's OpenSSL package, or any other OpenSSL that provides
      ECDH but not P224. Fixes bug 10835; bugfix on 0.2.4.8-alpha.
    - Turn "circuit handshake stats since last time" log messages into a
      heartbeat message. Fixes bug 10485; bugfix on 0.2.4.17-rc.

  o Documentation fixes:
    - Document that all but one DirPort entry must have the NoAdvertise
      flag set. Fixes bug 10470; bugfix on 0.2.3.3-alpha / 0.2.3.16-alpha.


Changes in version 0.2.5.2-alpha - 2014-02-13
  Tor 0.2.5.2-alpha includes all the fixes from 0.2.4.18-rc and 0.2.4.20,
  like the "poor random number generation" fix and the "building too many
  circuits" fix. It also further improves security against potential
  adversaries who find breaking 1024-bit crypto doable, and launches
  pluggable transports on demand (which gets us closer to integrating
  pluggable transport support by default -- not to be confused with Tor
  bundles enabling pluggable transports and bridges by default).

  o Major features (client security):
    - When we choose a path for a 3-hop circuit, make sure it contains
      at least one relay that supports the NTor circuit extension
      handshake. Otherwise, there is a chance that we're building
      a circuit that's worth attacking by an adversary who finds
      breaking 1024-bit crypto doable, and that chance changes the game
      theory. Implements ticket 9777.
    - Clients now look at the "usecreatefast" consensus parameter to
      decide whether to use CREATE_FAST or CREATE cells for the first hop
      of their circuit. This approach can improve security on connections
      where Tor's circuit handshake is stronger than the available TLS
      connection security levels, but the tradeoff is more computational
      load on guard relays. Implements proposal 221. Resolves ticket 9386.

  o Major features (bridges):
    - Don't launch pluggable transport proxies if we don't have any
      bridges configured that would use them. Now we can list many
      pluggable transports, and Tor will dynamically start one when it
      hears a bridge address that needs it. Resolves ticket 5018.
    - The bridge directory authority now assigns status flags (Stable,
      Guard, etc) to bridges based on thresholds calculated over all
      Running bridges. Now bridgedb can finally make use of its features
      to e.g. include at least one Stable bridge in its answers. Fixes
      bug 9859.

  o Major features (other):
    - Extend ORCONN controller event to include an "ID" parameter,
      and add four new controller event types CONN_BW, CIRC_BW,
      CELL_STATS, and TB_EMPTY that show connection and circuit usage.
      The new events are emitted in private Tor networks only, with the
      goal of being able to better track performance and load during
      full-network simulations. Implements proposal 218 and ticket 7359.
    - On some platforms (currently: recent OSX versions, glibc-based
      platforms that support the ELF format, and a few other
      Unix-like operating systems), Tor can now dump stack traces
      when a crash occurs or an assertion fails. By default, traces
      are dumped to stderr (if possible) and to any logs that are
      reporting errors. Implements ticket 9299.

  o Major bugfixes:
    - Avoid a segfault on SIGUSR1, where we had freed a connection but did
      not entirely remove it from the connection lists. Fixes bug 9602;
      bugfix on 0.2.4.4-alpha.
    - Do not treat streams that fail with reason
      END_STREAM_REASON_INTERNAL as indicating a definite circuit failure,
      since it could also indicate an ENETUNREACH connection error. Fixes
      part of bug 10777; bugfix on 0.2.4.8-alpha.

  o Major bugfixes (new since 0.2.5.1-alpha, also in 0.2.4.20):
    - Do not allow OpenSSL engines to replace the PRNG, even when
      HardwareAccel is set. The only default builtin PRNG engine uses
      the Intel RDRAND instruction to replace the entire PRNG, and
      ignores all attempts to seed it with more entropy. That's
      cryptographically stupid: the right response to a new alleged
      entropy source is never to discard all previously used entropy
      sources. Fixes bug 10402; works around behavior introduced in
      OpenSSL 1.0.0. Diagnosis and investigation thanks to "coderman"
      and "rl1987".
    - Fix assertion failure when AutomapHostsOnResolve yields an IPv6
      address. Fixes bug 10465; bugfix on 0.2.4.7-alpha.
    - Avoid launching spurious extra circuits when a stream is pending.
      This fixes a bug where any circuit that _wasn't_ unusable for new
      streams would be treated as if it were, causing extra circuits to
      be launched. Fixes bug 10456; bugfix on 0.2.4.12-alpha.

  o Major bugfixes (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
    - No longer stop reading or writing on cpuworker connections when
      our rate limiting buckets go empty. Now we should handle circuit
      handshake requests more promptly. Resolves bug 9731.
    - Stop trying to bootstrap all our directory information from
      only our first guard. Discovered while fixing bug 9946; bugfix
      on 0.2.4.8-alpha.

  o Minor features (bridges, pluggable transports):
    - Add threshold cutoffs to the networkstatus document created by
      the Bridge Authority. Fixes bug 1117.
    - On Windows, spawn background processes using the CREATE_NO_WINDOW
      flag. Now Tor Browser Bundle 3.5 with pluggable transports enabled
      doesn't pop up a blank console window. (In Tor Browser Bundle 2.x,
      Vidalia set this option for us.) Implements ticket 10297.

  o Minor features (security):
    - Always clear OpenSSL bignums before freeing them -- even bignums
      that don't contain secrets. Resolves ticket 10793. Patch by
      Florent Daignière.

  o Minor features (config options and command line):
    - Add an --allow-missing-torrc commandline option that tells Tor to
      run even if the configuration file specified by -f is not available.
      Implements ticket 10060.
    - Add support for the TPROXY transparent proxying facility on Linux.
      See documentation for the new TransProxyType option for more
      details. Implementation by "thomo". Closes ticket 10582.

  o Minor features (controller):
    - Add a new "HS_DESC" controller event that reports activities
      related to hidden service descriptors. Resolves ticket 8510.
    - New "DROPGUARDS" controller command to forget all current entry
      guards. Not recommended for ordinary use, since replacing guards
      too frequently makes several attacks easier. Resolves ticket 9934;
      patch from "ra".

  o Minor features (build):
    - Assume that a user using ./configure --host wants to cross-compile,
      and give an error if we cannot find a properly named
      tool-chain. Add a --disable-tool-name-check option to proceed
      nevertheless. Addresses ticket 9869. Patch by Benedikt Gollatz.
    - If we run ./configure and the compiler recognizes -fstack-protector
      but the linker rejects it, warn the user about a potentially missing
      libssp package. Addresses ticket 9948. Patch from Benedikt Gollatz.

  o Minor features (testing):
    - If Python is installed, "make check" now runs extra tests beyond
      the unit test scripts.
    - When bootstrapping a test network, sometimes very few relays get
      the Guard flag. Now a new option "TestingDirAuthVoteGuard" can
      specify a set of relays which should be voted Guard regardless of
      their uptime or bandwidth. Addresses ticket 9206.

  o Minor features (log messages):
    - When ServerTransportPlugin is set on a bridge, Tor can write more
      useful statistics about bridge use in its extrainfo descriptors,
      but only if the Extended ORPort ("ExtORPort") is set too. Add a
      log message to inform the user in this case. Resolves ticket 9651.
    - When receiving a new controller connection, log the origin address.
      Resolves ticket 9698; patch from "sigpipe".
    - When logging OpenSSL engine status at startup, log the status of
      more engines. Fixes ticket 10043; patch from Joshua Datko.
    - Turn "circuit handshake stats since last time" log messages into a
      heartbeat message. Fixes bug 10485; bugfix on 0.2.4.17-rc.

  o Minor features (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
    - Improve the circuit queue out-of-memory handler. Previously, when
      we ran low on memory, we'd close whichever circuits had the most
      queued cells. Now, we close those that have the *oldest* queued
      cells, on the theory that those are most responsible for us
      running low on memory. Based on analysis from a forthcoming paper
      by Jansen, Tschorsch, Johnson, and Scheuermann. Fixes bug 9093.
    - Generate bootstrapping status update events correctly when fetching
      microdescriptors. Fixes bug 9927.
    - Update to the October 2 2013 Maxmind GeoLite Country database.

  o Minor bugfixes (clients):
    - When closing a channel that has already been open, do not close
      pending circuits that were waiting to connect to the same relay.
      Fixes bug 9880; bugfix on 0.2.5.1-alpha. Thanks to skruffy for
      finding this bug.

  o Minor bugfixes (relays):
    - Treat ENETUNREACH, EACCES, and EPERM connection failures at an
      exit node as a NOROUTE error, not an INTERNAL error, since they
      can apparently happen when trying to connect to the wrong sort
      of netblocks. Fixes part of bug 10777; bugfix on 0.1.0.1-rc.

  o Minor bugfixes (bridges):
    - Fix a bug where the first connection works to a bridge that uses a
      pluggable transport with client-side parameters, but we don't send
      the client-side parameters on subsequent connections. (We don't
      use any pluggable transports with client-side parameters yet,
      but ScrambleSuit will soon become the first one.) Fixes bug 9162;
      bugfix on 0.2.0.3-alpha. Based on a patch from "rl1987".

  o Minor bugfixes (node selection):
    - If ExcludeNodes is set, consider non-excluded hidden service
      directory servers before excluded ones. Do not consider excluded
      hidden service directory servers at all if StrictNodes is
      set. (Previously, we would sometimes decide to connect to those
      servers, and then realize before we initiated a connection that
      we had excluded them.) Fixes bug 10722; bugfix on 0.2.0.10-alpha.
      Reported by "mr-4".
    - If we set the ExitNodes option but it doesn't include any nodes
      that have the Exit flag, we would choose not to bootstrap. Now we
      bootstrap so long as ExitNodes includes nodes which can exit to
      some port. Fixes bug 10543; bugfix on 0.2.4.10-alpha.

  o Minor bugfixes (controller and command-line):
    - If changing a config option via "setconf" fails in a recoverable
      way, we used to nonetheless write our new control ports to the
      file described by the "ControlPortWriteToFile" option. Now we only
      write out that file if we successfully switch to the new config
      option. Fixes bug 5605; bugfix on 0.2.2.26-beta. Patch from "Ryman".
    - When a command-line option such as --version or --help that
      ordinarily implies --hush appears on the command line along with
      --quiet, then actually obey --quiet. Previously, we obeyed --quiet
      only if it appeared later on the command line. Fixes bug 9578;
      bugfix on 0.2.5.1-alpha.

  o Minor bugfixes (code correctness):
    - Previously we used two temporary files when writing descriptors to
      disk; now we only use one. Fixes bug 1376.
    - Remove an erroneous (but impossible and thus harmless) pointer
      comparison that would have allowed compilers to skip a bounds
      check in channeltls.c. Fixes bugs 10313 and 9980; bugfix on
      0.2.0.10-alpha. Noticed by Jared L Wong and David Fifield.
    - Fix an always-true assertion in pluggable transports code so it
      actually checks what it was trying to check. Fixes bug 10046;
      bugfix on 0.2.3.9-alpha. Found by "dcb".

  o Minor bugfixes (protocol correctness):
    - When receiving a VERSIONS cell with an odd number of bytes, close
      the connection immediately since the cell is malformed. Fixes bug
      10365; bugfix on 0.2.0.10-alpha. Spotted by "bobnomnom"; fix by
      "rl1987".

  o Minor bugfixes (build):
    - Restore the ability to compile Tor with V2_HANDSHAKE_SERVER
      turned off (that is, without support for v2 link handshakes). Fixes
      bug 4677; bugfix on 0.2.3.2-alpha. Patch from "piet".
    - Fix compilation warnings and startup issues when running with
      "Sandbox 1" and libseccomp-2.1.0. Fixes bug 10563; bugfix on
      0.2.5.1-alpha.
    - Fix compilation on Solaris 9, which didn't like us having an
      identifier named "sun". Fixes bug 10565; bugfix in 0.2.5.1-alpha.

  o Minor bugfixes (testing):
    - Fix a segmentation fault in our benchmark code when running with
      Fedora's OpenSSL package, or any other OpenSSL that provides
      ECDH but not P224. Fixes bug 10835; bugfix on 0.2.4.8-alpha.

  o Minor bugfixes (log messages):
    - Fix a bug where clients using bridges would report themselves
      as 50% bootstrapped even without a live consensus document.
      Fixes bug 9922; bugfix on 0.2.1.1-alpha.
    - Suppress a warning where, if there's only one directory authority
      in the network, we would complain that votes and signatures cannot
      be uploaded to other directory authorities. Fixes bug 10842;
      bugfix on 0.2.2.26-beta.
    - Report bootstrapping progress correctly when we're downloading
      microdescriptors. We had updated our "do we have enough microdescs
      to begin building circuits?" logic most recently in 0.2.4.10-alpha
      (see bug 5956), but we left the bootstrap status event logic at
      "how far through getting 1/4 of them are we?" Fixes bug 9958;
      bugfix on 0.2.2.36, which is where they diverged (see bug 5343).

  o Minor bugfixes (new since 0.2.5.1-alpha, also in 0.2.4.20):
    - Avoid a crash bug when starting with a corrupted microdescriptor
      cache file. Fixes bug 10406; bugfix on 0.2.2.6-alpha.
    - If we fail to dump a previously cached microdescriptor to disk, avoid
      freeing duplicate data later on. Fixes bug 10423; bugfix on
      0.2.4.13-alpha. Spotted by "bobnomnom".

  o Minor bugfixes on 0.2.4.x (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
    - Correctly log long IPv6 exit policies, instead of truncating them
      or reporting an error. Fixes bug 9596; bugfix on 0.2.4.7-alpha.
    - Our default TLS ecdhe groups were backwards: we meant to be using
      P224 for relays (for performance win) and P256 for bridges (since
      it is more common in the wild). Instead we had it backwards. After
      reconsideration, we decided that the default should be P256 on all
      hosts, since its security is probably better, and since P224 is
      reportedly used quite little in the wild.  Found by "skruffy" on
      IRC. Fix for bug 9780; bugfix on 0.2.4.8-alpha.
    - Free directory authority certificate download statuses on exit
      rather than leaking them. Fixes bug 9644; bugfix on 0.2.4.13-alpha.

  o Minor bugfixes on 0.2.3.x (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
    - If the guard we choose first doesn't answer, we would try the
      second guard, but once we connected to the second guard we would
      abandon it and retry the first one, slowing down bootstrapping.
      The fix is to treat all our initially chosen guards as acceptable
      to use. Fixes bug 9946; bugfix on 0.1.1.11-alpha.
    - Fix an assertion failure that would occur when disabling the
      ORPort setting on a running Tor process while accounting was
      enabled. Fixes bug 6979; bugfix on 0.2.2.18-alpha.
    - When examining the list of network interfaces to find our address,
      do not consider non-running or disabled network interfaces. Fixes
      bug 9904; bugfix on 0.2.3.11-alpha. Patch from "hantwister".
    - Avoid an off-by-one error when checking buffer boundaries when
      formatting the exit status of a pluggable transport helper.
      This is probably not an exploitable bug, but better safe than
      sorry. Fixes bug 9928; bugfix on 0.2.3.18-rc. Bug found by
      Pedro Ribeiro.

  o Removed code and features:
    - Clients now reject any directory authority certificates lacking
      a dir-key-crosscert element. These have been included since
      0.2.1.9-alpha, so there's no real reason for them to be optional
      any longer. Completes proposal 157. Resolves ticket 10162.
    - Remove all code that existed to support the v2 directory system,
      since there are no longer any v2 directory authorities. Resolves
      ticket 10758.
    - Remove the HSAuthoritativeDir and AlternateHSAuthority torrc
      options, which were used for designating authorities as "Hidden
      service authorities". There has been no use of hidden service
      authorities since 0.2.2.1-alpha, when we stopped uploading or
      downloading v0 hidden service descriptors. Fixes bug 10881; also
      part of a fix for bug 10841.

  o Code simplification and refactoring:
    - Remove some old fallback code designed to keep Tor clients working
      in a network with only two working relays. Elsewhere in the code we
      have long since stopped supporting such networks, so there wasn't
      much point in keeping it around. Addresses ticket 9926.
    - Reject 0-length EXTEND2 cells more explicitly. Fixes bug 10536;
      bugfix on 0.2.4.8-alpha. Reported by "cypherpunks".
    - Remove data structures which were introduced to implement the
      CellStatistics option: they are now redundant with the addition
      of a timestamp to the regular packed_cell_t data structure, which
      we did in 0.2.4.18-rc in order to resolve ticket 9093. Implements
      ticket 10870.

  o Documentation (man page) fixes:
    - Update manpage to describe some of the files you can expect to
      find in Tor's DataDirectory. Addresses ticket 9839.
    - Document that all but one DirPort entry must have the NoAdvertise
      flag set. Fixes bug 10470; bugfix on 0.2.3.3-alpha / 0.2.3.16-alpha.

  o Documentation fixes (new since 0.2.5.1-alpha, also in 0.2.4.18-rc):
    - Clarify the usage and risks of setting the ContactInfo torrc line
      for your relay or bridge. Resolves ticket 9854.
    - Add anchors to the manpage so we can link to the html version of
      the documentation for specific options. Resolves ticket 9866.
    - Replace remaining references to DirServer in man page and
      log entries. Resolves ticket 10124.

  o Tool changes:
    - Make the "tor-gencert" tool used by directory authority operators
      create 2048-bit signing keys by default (rather than 1024-bit, since
      1024-bit is uncomfortably small these days). Addresses ticket 10324.


Changes in version 0.2.4.20 - 2013-12-22
  Tor 0.2.4.20 fixes potentially poor random number generation for users
  who 1) use OpenSSL 1.0.0 or later, 2) set "HardwareAccel 1" in their
  torrc file, 3) have "Sandy Bridge" or "Ivy Bridge" Intel processors,
  and 4) have no state file in their DataDirectory (as would happen on
  first start). Users who generated relay or hidden service identity
  keys in such a situation should discard them and generate new ones.

  This release also fixes a logic error that caused Tor clients to build
  many more preemptive circuits than they actually need.

  o Major bugfixes:
    - Do not allow OpenSSL engines to replace the PRNG, even when
      HardwareAccel is set. The only default builtin PRNG engine uses
      the Intel RDRAND instruction to replace the entire PRNG, and
      ignores all attempts to seed it with more entropy. That's
      cryptographically stupid: the right response to a new alleged
      entropy source is never to discard all previously used entropy
      sources. Fixes bug 10402; works around behavior introduced in
      OpenSSL 1.0.0. Diagnosis and investigation thanks to "coderman"
      and "rl1987".
    - Fix assertion failure when AutomapHostsOnResolve yields an IPv6
      address. Fixes bug 10465; bugfix on 0.2.4.7-alpha.
    - Avoid launching spurious extra circuits when a stream is pending.
      This fixes a bug where any circuit that _wasn't_ unusable for new
      streams would be treated as if it were, causing extra circuits to
      be launched. Fixes bug 10456; bugfix on 0.2.4.12-alpha.

  o Minor bugfixes:
    - Avoid a crash bug when starting with a corrupted microdescriptor
      cache file. Fixes bug 10406; bugfix on 0.2.2.6-alpha.
    - If we fail to dump a previously cached microdescriptor to disk, avoid
      freeing duplicate data later on. Fixes bug 10423; bugfix on
      0.2.4.13-alpha. Spotted by "bobnomnom".


Changes in version 0.2.4.19 - 2013-12-11
  The Tor 0.2.4 release series is dedicated to the memory of Aaron Swartz
  (1986-2013). Aaron worked on diverse projects including helping to guide
  Creative Commons, playing a key role in stopping SOPA/PIPA, bringing
  transparency to the U.S government's PACER documents, and contributing
  design and development for Tor and Tor2Web. Aaron was one of the latest
  martyrs in our collective fight for civil liberties and human rights,
  and his death is all the more painful because he was one of us.

  Tor 0.2.4.19, the first stable release in the 0.2.4 branch, features
  a new circuit handshake and link encryption that use ECC to provide
  better security and efficiency; makes relays better manage circuit
  creation requests; uses "directory guards" to reduce client enumeration
  risks; makes bridges collect and report statistics about the pluggable
  transports they support; cleans up and improves our geoip database;
  gets much closer to IPv6 support for clients, bridges, and relays; makes
  directory authorities use measured bandwidths rather than advertised
  ones when computing flags and thresholds; disables client-side DNS
  caching to reduce tracking risks; and fixes a big bug in bridge
  reachability testing. This release introduces two new design
  abstractions in the code: a new "channel" abstraction between circuits
  and or_connections to allow for implementing alternate relay-to-relay
  transports, and a new "circuitmux" abstraction storing the queue of
  circuits for a channel. The release also includes many stability,
  security, and privacy fixes.


Changes in version 0.2.4.18-rc - 2013-11-16
  Tor 0.2.4.18-rc is the fourth release candidate for the Tor 0.2.4.x
  series. It takes a variety of fixes from the 0.2.5.x branch to improve
  stability, performance, and better handling of edge cases.

  o Major features:
    - Re-enable TLS 1.1 and 1.2 when built with OpenSSL 1.0.1e or later.
      Resolves ticket 6055. (OpenSSL before 1.0.1 didn't have TLS 1.1 or
      1.2, and OpenSSL from 1.0.1 through 1.0.1d had bugs that prevented
      renegotiation from working with TLS 1.1 or 1.2, so we had disabled
      them to solve bug 6033.)

  o Major bugfixes:
    - No longer stop reading or writing on cpuworker connections when
      our rate limiting buckets go empty. Now we should handle circuit
      handshake requests more promptly. Resolves bug 9731.
    - If we are unable to save a microdescriptor to the journal, do not
      drop it from memory and then reattempt downloading it. Fixes bug
      9645; bugfix on 0.2.2.6-alpha.
    - Stop trying to bootstrap all our directory information from
      only our first guard. Discovered while fixing bug 9946; bugfix
      on 0.2.4.8-alpha.
    - The new channel code sometimes lost track of in-progress circuits,
      causing long-running clients to stop building new circuits. The
      fix is to always call circuit_n_chan_done(chan, 0) from
      channel_closed(). Fixes bug 9776; bugfix on 0.2.4.17-rc.

  o Minor bugfixes (on 0.2.4.x):
    - Correctly log long IPv6 exit policies, instead of truncating them
      or reporting an error. Fixes bug 9596; bugfix on 0.2.4.7-alpha.
    - Our default TLS ecdhe groups were backwards: we meant to be using
      P224 for relays (for performance win) and P256 for bridges (since
      it is more common in the wild). Instead we had it backwards. After
      reconsideration, we decided that the default should be P256 on all
      hosts, since its security is probably better, and since P224 is
      reportedly used quite little in the wild.  Found by "skruffy" on
      IRC. Fix for bug 9780; bugfix on 0.2.4.8-alpha.
    - Free directory authority certificate download statuses on exit
      rather than leaking them. Fixes bug 9644; bugfix on 0.2.4.13-alpha.

  o Minor bugfixes (on 0.2.3.x and earlier):
    - If the guard we choose first doesn't answer, we would try the
      second guard, but once we connected to the second guard we would
      abandon it and retry the first one, slowing down bootstrapping.
      The fix is to treat all our initially chosen guards as acceptable
      to use. Fixes bug 9946; bugfix on 0.1.1.11-alpha.
    - Fix an assertion failure that would occur when disabling the
      ORPort setting on a running Tor process while accounting was
      enabled. Fixes bug 6979; bugfix on 0.2.2.18-alpha.
    - When examining the list of network interfaces to find our address,
      do not consider non-running or disabled network interfaces. Fixes
      bug 9904; bugfix on 0.2.3.11-alpha. Patch from "hantwister".
    - Avoid an off-by-one error when checking buffer boundaries when
      formatting the exit status of a pluggable transport helper.
      This is probably not an exploitable bug, but better safe than
      sorry. Fixes bug 9928; bugfix on 0.2.3.18-rc. Bug found by
      Pedro Ribeiro.

  o Minor features (protecting client timestamps):
    - Clients no longer send timestamps in their NETINFO cells. These were
      not used for anything, and they provided one small way for clients
      to be distinguished from each other as they moved from network to
      network or behind NAT. Implements part of proposal 222.
    - Clients now round timestamps in INTRODUCE cells down to the nearest
      10 minutes. If a new Support022HiddenServices option is set to 0, or
      if it's set to "auto" and the feature is disabled in the consensus,
      the timestamp is sent as 0 instead. Implements part of proposal 222.
    - Stop sending timestamps in AUTHENTICATE cells. This is not such
      a big deal from a security point of view, but it achieves no actual
      good purpose, and isn't needed. Implements part of proposal 222.
    - Reduce down accuracy of timestamps in hidden service descriptors.
      Implements part of proposal 222.

  o Minor features (other):
    - Improve the circuit queue out-of-memory handler. Previously, when
      we ran low on memory, we'd close whichever circuits had the most
      queued cells. Now, we close those that have the *oldest* queued
      cells, on the theory that those are most responsible for us
      running low on memory. Based on analysis from a forthcoming paper
      by Jansen, Tschorsch, Johnson, and Scheuermann. Fixes bug 9093.
    - Generate bootstrapping status update events correctly when fetching
      microdescriptors. Fixes bug 9927.
    - Update to the October 2 2013 Maxmind GeoLite Country database.

  o Documentation fixes:
    - Clarify the usage and risks of setting the ContactInfo torrc line
      for your relay or bridge. Resolves ticket 9854.
    - Add anchors to the manpage so we can link to the html version of
      the documentation for specific options. Resolves ticket 9866.
    - Replace remaining references to DirServer in man page and
      log entries. Resolves ticket 10124.


Changes in version 0.2.5.1-alpha - 2013-10-02
  Tor 0.2.5.1-alpha introduces experimental support for syscall sandboxing
  on Linux, allows bridges that offer pluggable transports to report usage
  statistics, fixes many issues to make testing easier, and provides
  a pile of minor features and bugfixes that have been waiting for a
  release of the new branch.

  This is the first alpha release in a new series, so expect there to
  be bugs. Users who would rather test out a more stable branch should
  stay with 0.2.4.x for now.

  o Major features (security):
    - Use the seccomp2 syscall filtering facility on Linux to limit
      which system calls Tor can invoke. This is an experimental,
      Linux-only feature to provide defense-in-depth against unknown
      attacks. To try turning it on, set "Sandbox 1" in your torrc
      file. Please be ready to report bugs. We hope to add support
      for better sandboxing in the future, including more fine-grained
      filters, better division of responsibility, and support for more
      platforms. This work has been done by Cristian-Matei Toader for
      Google Summer of Code.
    - Re-enable TLS 1.1 and 1.2 when built with OpenSSL 1.0.1e or later.
      Resolves ticket 6055. (OpenSSL before 1.0.1 didn't have TLS 1.1 or
      1.2, and OpenSSL from 1.0.1 through 1.0.1d had bugs that prevented
      renegotiation from working with TLS 1.1 or 1.2, so we had disabled
      them to solve bug 6033.)

  o Major features (other):
    - Add support for passing arguments to managed pluggable transport
      proxies. Implements ticket 3594.
    - Bridges now track GeoIP information and the number of their users
      even when pluggable transports are in use, and report usage
      statistics in their extra-info descriptors. Resolves tickets 4773
      and 5040.
    - Make testing Tor networks bootstrap better: lower directory fetch
      retry schedules and maximum interval without directory requests,
      and raise maximum download tries. Implements ticket 6752.
    - Add make target 'test-network' to run tests on a Chutney network.
      Implements ticket 8530.
    - The ntor handshake is now on-by-default, no matter what the
      directory authorities recommend. Implements ticket 8561.

  o Major bugfixes:
    - Instead of writing destroy cells directly to outgoing connection
      buffers, queue them and intersperse them with other outgoing cells.
      This can prevent a set of resource starvation conditions where too
      many pending destroy cells prevent data cells from actually getting
      delivered. Reported by "oftc_must_be_destroyed". Fixes bug 7912;
      bugfix on 0.2.0.1-alpha.
    - If we are unable to save a microdescriptor to the journal, do not
      drop it from memory and then reattempt downloading it. Fixes bug
      9645; bugfix on 0.2.2.6-alpha.
    - The new channel code sometimes lost track of in-progress circuits,
      causing long-running clients to stop building new circuits. The
      fix is to always call circuit_n_chan_done(chan, 0) from
      channel_closed(). Fixes bug 9776; bugfix on 0.2.4.17-rc.

  o Build features:
    - Tor now builds each source file in two modes: a mode that avoids
      exposing identifiers needlessly, and another mode that exposes
      more identifiers for testing. This lets the compiler do better at
      optimizing the production code, while enabling us to take more
      radical measures to let the unit tests test things.
    - The production builds no longer include functions used only in
      the unit tests; all functions exposed from a module only for
      unit-testing are now static in production builds.
    - Add an --enable-coverage configuration option to make the unit
      tests (and a new src/or/tor-cov target) to build with gcov test
      coverage support.

  o Testing:
    - We now have rudimentary function mocking support that our unit
      tests can use to test functions in isolation. Function mocking
      lets the tests temporarily replace a function's dependencies with
      stub functions, so that the tests can check the function without
      invoking the other functions it calls.
    - Add more unit tests for the <circid,channel>->circuit map, and
      the destroy-cell-tracking code to fix bug 7912.
    - Unit tests for failing cases of the TAP onion handshake.
    - More unit tests for address-manipulation functions.

  o Minor features (protecting client timestamps):
    - Clients no longer send timestamps in their NETINFO cells. These were
      not used for anything, and they provided one small way for clients
      to be distinguished from each other as they moved from network to
      network or behind NAT. Implements part of proposal 222.
    - Clients now round timestamps in INTRODUCE cells down to the nearest
      10 minutes. If a new Support022HiddenServices option is set to 0, or
      if it's set to "auto" and the feature is disabled in the consensus,
      the timestamp is sent as 0 instead. Implements part of proposal 222.
    - Stop sending timestamps in AUTHENTICATE cells. This is not such
      a big deal from a security point of view, but it achieves no actual
      good purpose, and isn't needed. Implements part of proposal 222.
    - Reduce down accuracy of timestamps in hidden service descriptors.
      Implements part of proposal 222.

  o Minor features (config options):
    - Config (torrc) lines now handle fingerprints which are missing
      their initial '$'. Resolves ticket 4341; improvement over 0.0.9pre5.
    - Support a --dump-config option to print some or all of the
      configured options. Mainly useful for debugging the command-line
      option parsing code. Helps resolve ticket 4647.
    - Raise awareness of safer logging: notify user of potentially
      unsafe config options, like logging more verbosely than severity
      "notice" or setting SafeLogging to 0. Resolves ticket 5584.
    - Add a new configuration option TestingV3AuthVotingStartOffset
      that bootstraps a network faster by changing the timing for
      consensus votes. Addresses ticket 8532.
    - Add a new torrc option "ServerTransportOptions" that allows
      bridge operators to pass configuration parameters to their
      pluggable transports. Resolves ticket 8929.
    - The config (torrc) file now accepts bandwidth and space limits in
      bits as well as bytes. (Anywhere that you can say "2 Kilobytes",
      you can now say "16 kilobits", and so on.) Resolves ticket 9214.
      Patch by CharlieB.

  o Minor features (build):
    - Add support for `--library-versions` flag. Implements ticket 6384.
    - Return the "unexpected sendme" warnings to a warn severity, but make
      them rate limited, to help diagnose ticket 8093.
    - Detect a missing asciidoc, and warn the user about it, during
      configure rather than at build time. Fixes issue 6506. Patch from
      Arlo Breault.

  o Minor features (other):
    - Use the SOCK_NONBLOCK socket type, if supported, to open nonblocking
      sockets in a single system call. Implements ticket 5129.
    - Log current accounting state (bytes sent and received + remaining
      time for the current accounting period) in the relay's heartbeat
      message. Implements ticket 5526; patch from Peter Retzlaff.
    - Implement the TRANSPORT_LAUNCHED control port event that
      notifies controllers about new launched pluggable
      transports. Resolves ticket 5609.
    - If we're using the pure-C 32-bit curve25519_donna implementation
      of curve25519, build it with the -fomit-frame-pointer option to
      make it go faster on register-starved hosts. This improves our
      handshake performance by about 6% on i386 hosts without nacl.
      Closes ticket 8109.
    - Update to the September 4 2013 Maxmind GeoLite Country database.

  o Minor bugfixes:
    - Set the listen() backlog limit to the largest actually supported
      on the system, not to the value in a header file. Fixes bug 9716;
      bugfix on every released Tor.
    - No longer accept malformed http headers when parsing urls from
      headers. Now we reply with Bad Request ("400"). Fixes bug 2767;
      bugfix on 0.0.6pre1.
    - In munge_extrainfo_into_routerinfo(), check the return value of
      memchr(). This would have been a serious issue if we ever passed
      it a non-extrainfo. Fixes bug 8791; bugfix on 0.2.0.6-alpha. Patch
      from Arlo Breault.
    - On the chance that somebody manages to build Tor on a
      platform where time_t is unsigned, correct the way that
      microdesc_add_to_cache() handles negative time arguments.
      Fixes bug 8042; bugfix on 0.2.3.1-alpha.
    - Reject relative control socket paths and emit a warning. Previously,
      single-component control socket paths would be rejected, but Tor
      would not log why it could not validate the config. Fixes bug 9258;
      bugfix on 0.2.3.16-alpha.

  o Minor bugfixes (command line):
    - Use a single command-line parser for parsing torrc options on the
      command line and for finding special command-line options to avoid
      inconsistent behavior for torrc option arguments that have the same
      names as command-line options. Fixes bugs 4647 and 9578; bugfix on
      0.0.9pre5.
    - No longer allow 'tor --hash-password' with no arguments. Fixes bug
      9573; bugfix on 0.0.9pre5.

  o Minor fixes (build, auxiliary programs):
    - Stop preprocessing the "torify" script with autoconf, since
      it no longer refers to LOCALSTATEDIR. Fixes bug 5505; patch
      from Guilhem.
    - The tor-fw-helper program now follows the standard convention and
      exits with status code "0" on success. Fixes bug 9030; bugfix on
      0.2.3.1-alpha. Patch by Arlo Breault.
    - Corrected ./configure advice for what openssl dev package you should
      install on Debian. Fixes bug 9207; bugfix on 0.2.0.1-alpha.

  o Minor code improvements:
    - Remove constants and tests for PKCS1 padding; it's insecure and
      shouldn't be used for anything new. Fixes bug 8792; patch
      from Arlo Breault.
    - Remove instances of strcpy() from the unit tests. They weren't
      hurting anything, since they were only in the unit tests, but it's
      embarassing to have strcpy() in the code at all, and some analysis
      tools don't like it. Fixes bug 8790; bugfix on 0.2.3.6-alpha and
      0.2.3.8-alpha. Patch from Arlo Breault.

  o Removed features:
    - Remove migration code from when we renamed the "cached-routers"
      file to "cached-descriptors" back in 0.2.0.8-alpha. This
      incidentally resolves ticket 6502 by cleaning up the related code
      a bit. Patch from Akshay Hebbar.

  o Code simplification and refactoring:
    - Extract the common duplicated code for creating a subdirectory
      of the data directory and writing to a file in it. Fixes ticket
      4282; patch from Peter Retzlaff.
    - Since OpenSSL 0.9.7, the i2d_*() functions support allocating output
      buffer. Avoid calling twice: i2d_RSAPublicKey(), i2d_DHparams(),
      i2d_X509(), and i2d_PublicKey(). Resolves ticket 5170.
    - Add a set of accessor functions for the circuit timeout data
      structure. Fixes ticket 6153; patch from "piet".
    - Clean up exit paths from connection_listener_new(). Closes ticket
      8789. Patch from Arlo Breault.
    - Since we rely on OpenSSL 0.9.8 now, we can use EVP_PKEY_cmp()
      and drop our own custom pkey_eq() implementation. Fixes bug 9043.
    - Use a doubly-linked list to implement the global circuit list.
      Resolves ticket 9108. Patch from Marek Majkowski.
    - Remove contrib/id_to_fp.c since it wasn't used anywhere.


Changes in version 0.2.4.17-rc - 2013-09-05
  Tor 0.2.4.17-rc is the third release candidate for the Tor 0.2.4.x
  series. It adds an emergency step to help us tolerate the massive
  influx of users: 0.2.4 clients using the new (faster and safer) "NTor"
  circuit-level handshakes now effectively jump the queue compared to
  the 0.2.3 clients using "TAP" handshakes. This release also fixes a
  big bug hindering bridge reachability tests.

  o Major features:
    - Relays now process the new "NTor" circuit-level handshake requests
      with higher priority than the old "TAP" circuit-level handshake
      requests. We still process some TAP requests to not totally starve
      0.2.3 clients when NTor becomes popular. A new consensus parameter
      "NumNTorsPerTAP" lets us tune the balance later if we need to.
      Implements ticket 9574.

  o Major bugfixes:
    - If the circuit build timeout logic is disabled (via the consensus,
      or because we are an authority), then don't build testing circuits.
      Fixes bug 9657; bugfix on 0.2.2.14-alpha.
    - Bridges now send AUTH_CHALLENGE cells during their v3 handshakes;
      previously they did not, which prevented them from receiving
      successful connections from relays for self-test or bandwidth
      testing. Also, when a relay is extending a circuit to a bridge,
      it needs to send a NETINFO cell, even when the bridge hasn't sent
      an AUTH_CHALLENGE cell. Fixes bug 9546; bugfix on 0.2.3.6-alpha.
    - If the time to download the next old-style networkstatus is in
      the future, do not decline to consider whether to download the
      next microdescriptor networkstatus. Fixes bug 9564; bugfix on
      0.2.3.14-alpha.

  o Minor bugfixes:
    - Avoid double-closing the listener socket in our socketpair()
      replacement (used on Windows) in the case where the addresses on
      our opened sockets don't match what we expected. Fixes bug 9400;
      bugfix on 0.0.2pre7. Found by Coverity.

  o Minor fixes (config options):
    - Avoid overflows when the user sets MaxCircuitDirtiness to a
      ridiculously high value, by imposing a (ridiculously high) 30-day
      maximum on MaxCircuitDirtiness.
    - Fix the documentation of HeartbeatPeriod to say that the heartbeat
      message is logged at notice, not at info.
    - Warn and fail if a server is configured not to advertise any
      ORPorts at all. (We need *something* to put in our descriptor,
      or we just won't work.)

  o Minor features:
    - Track how many "TAP" and "NTor" circuit handshake requests we get,
      and how many we complete, and log it every hour to help relay
      operators follow trends in network load. Addresses ticket 9658.
    - Update to the August 7 2013 Maxmind GeoLite Country database.


Changes in version 0.2.4.16-rc - 2013-08-10
  Tor 0.2.4.16-rc is the second release candidate for the Tor 0.2.4.x
  series. It fixes several crash bugs in the 0.2.4 branch.

  o Major bugfixes:
    - Fix a bug in the voting algorithm that could yield incorrect results
      when a non-naming authority declared too many flags. Fixes bug 9200;
      bugfix on 0.2.0.3-alpha.
    - Fix an uninitialized read that could in some cases lead to a remote
      crash while parsing INTRODUCE2 cells. Bugfix on 0.2.4.1-alpha.
      Anybody running a hidden service on the experimental 0.2.4.x
      branch should upgrade. (This is, so far as we know, unrelated to
      the recent news.)
    - Avoid an assertion failure when processing DNS replies without the
      answer types we expected. Fixes bug 9337; bugfix on 0.2.4.7-alpha.
    - Avoid a crash when using --hash-password. Fixes bug 9295; bugfix on
      0.2.4.15-rc. Found by stem integration tests.

  o Minor bugfixes:
    - Fix an invalid memory read that occured when a pluggable
      transport proxy failed its configuration protocol.
      Fixes bug 9288; bugfix on 0.2.4.1-alpha.
    - When evaluating whether to use a connection that we haven't
      decided is canonical using a recent link protocol version,
      decide that it's canonical only if it used address _does_
      match the desired address. Fixes bug 9309; bugfix on
      0.2.4.4-alpha. Reported by skruffy.
    - Make the default behavior of NumDirectoryGuards be to track
      NumEntryGuards. Now a user who changes only NumEntryGuards will get
      the behavior she expects. Fixes bug 9354; bugfix on 0.2.4.8-alpha.
    - Fix a spurious compilation warning with some older versions of
      GCC on FreeBSD. Fixes bug 9254; bugfix on 0.2.4.14-alpha.

  o Minor features:
    - Update to the July 3 2013 Maxmind GeoLite Country database.


Changes in version 0.2.4.15-rc - 2013-07-01
  Tor 0.2.4.15-rc is the first release candidate for the Tor 0.2.4.x
  series. It fixes a few smaller bugs, but generally appears stable.
  Please test it and let us know whether it is!

  o Major bugfixes:
    - When receiving a new configuration file via the control port's
      LOADCONF command, do not treat the defaults file as absent.
      Fixes bug 9122; bugfix on 0.2.3.9-alpha.

  o Minor features:
    - Issue a warning when running with the bufferevents backend enabled.
      It's still not stable, and people should know that they're likely
      to hit unexpected problems. Closes ticket 9147.


Changes in version 0.2.4.14-alpha - 2013-06-18
  Tor 0.2.4.14-alpha fixes a pair of client guard enumeration problems
  present in 0.2.4.13-alpha.

  o Major bugfixes:
    - When we have too much memory queued in circuits (according to a new
      MaxMemInCellQueues option), close the circuits consuming the most
      memory. This prevents us from running out of memory as a relay if
      circuits fill up faster than they can be drained. Fixes bug 9063;
      bugfix on the 54th commit of Tor. This bug is a further fix beyond
      bug 6252, whose fix was merged into 0.2.3.21-rc.

      This change also fixes an earlier approach taken in 0.2.4.13-alpha,
      where we tried to solve this issue simply by imposing an upper limit
      on the number of queued cells for a single circuit. That approach
      proved to be problematic, since there are ways to provoke clients to
      send a number of cells in excess of any such reasonable limit. Fixes
      bug 9072; bugfix on 0.2.4.13-alpha.

    - Limit hidden service descriptors to at most ten introduction
      points, to slow one kind of guard enumeration. Fixes bug 9002;
      bugfix on 0.1.1.11-alpha.


Changes in version 0.2.4.13-alpha - 2013-06-14
  Tor 0.2.4.13-alpha fixes a variety of potential remote crash
  vulnerabilities, makes socks5 username/password circuit isolation
  actually actually work (this time for sure!), and cleans up a bunch
  of other issues in preparation for a release candidate.

  o Major bugfixes (robustness):
    - Close any circuit that has too many cells queued on it. Fixes
      bug 9063; bugfix on the 54th commit of Tor. This bug is a further
      fix beyond bug 6252, whose fix was merged into 0.2.3.21-rc.
    - Prevent the get_freelists() function from running off the end of
      the list of freelists if it somehow gets an unrecognized
      allocation. Fixes bug 8844; bugfix on 0.2.0.16-alpha. Reported by
      eugenis.
    - Avoid an assertion failure on OpenBSD (and perhaps other BSDs)
      when an exit connection with optimistic data succeeds immediately
      rather than returning EINPROGRESS. Fixes bug 9017; bugfix on
      0.2.3.1-alpha.
    - Fix a directory authority crash bug when building a consensus
      using an older consensus as its basis. Fixes bug 8833. Bugfix
      on 0.2.4.12-alpha.

  o Major bugfixes:
    - Avoid a memory leak where we would leak a consensus body when we
      find that a consensus which we couldn't previously verify due to
      missing certificates is now verifiable. Fixes bug 8719; bugfix
      on 0.2.0.10-alpha.
    - We used to always request authority certificates by identity digest,
      meaning we'd get the newest one even when we wanted one with a
      different signing key. Then we would complain about being given
      a certificate we already had, and never get the one we really
      wanted. Now we use the "fp-sk/" resource as well as the "fp/"
      resource to request the one we want. Fixes bug 5595; bugfix on
      0.2.0.8-alpha.
    - Follow the socks5 protocol when offering username/password
      authentication. The fix for bug 8117 exposed this bug, and it
      turns out real-world applications like Pidgin do care. Bugfix on
      0.2.3.2-alpha; fixes bug 8879.
    - Prevent failures on Windows Vista and later when rebuilding the
      microdescriptor cache. Diagnosed by Robert Ransom. Fixes bug 8822;
      bugfix on 0.2.4.12-alpha.

  o Minor bugfixes:
    - Fix an impossible buffer overrun in the AES unit tests. Fixes
      bug 8845; bugfix on 0.2.0.7-alpha. Found by eugenis.
    - If for some reason we fail to write a microdescriptor while
      rebuilding the cache, do not let the annotations from that
      microdescriptor linger in the cache file, and do not let the
      microdescriptor stay recorded as present in its old location.
      Fixes bug 9047; bugfix on 0.2.2.6-alpha.
    - Fix a memory leak that would occur whenever a configuration
      option changed. Fixes bug 8718; bugfix on 0.2.3.3-alpha.
    - Paste the description for PathBias parameters from the man
      page into or.h, so the code documents them too. Fixes bug 7982;
      bugfix on 0.2.3.17-beta and 0.2.4.8-alpha.
    - Relays now treat a changed IPv6 ORPort as sufficient reason to
      publish an updated descriptor. Fixes bug 6026; bugfix on
      0.2.4.1-alpha.
    - When launching a resolve request on behalf of an AF_UNIX control
      socket, omit the address field of the new entry connection, used in
      subsequent controller events, rather than letting tor_dup_addr()
      set it to "<unknown address type>". Fixes bug 8639; bugfix on
      0.2.4.12-alpha.

  o Minor bugfixes (log messages):
    - Fix a scaling issue in the path bias accounting code that
      resulted in "Bug:" log messages from either
      pathbias_scale_close_rates() or pathbias_count_build_success().
      This represents a bugfix on a previous bugfix: the original fix
      attempted in 0.2.4.10-alpha was incomplete. Fixes bug 8235; bugfix
      on 0.2.4.1-alpha.
    - Give a less useless error message when the user asks for an IPv4
      address on an IPv6-only port, or vice versa. Fixes bug 8846; bugfix
      on 0.2.4.7-alpha.

  o Minor features:
    - Downgrade "unexpected SENDME" warnings to protocol-warn for 0.2.4.x,
      to tolerate bug 8093 for now.
    - Add an "ignoring-advertised-bws" boolean to the flag-threshold lines
      in directory authority votes to describe whether they have enough
      measured bandwidths to ignore advertised (relay descriptor)
      bandwidth claims. Resolves ticket 8711.
    - Update to the June 5 2013 Maxmind GeoLite Country database.

  o Removed documentation:
    - Remove some of the older contents of doc/ as obsolete; move others
      to torspec.git. Fixes bug 8965.

  o Code simplification and refactoring:
    - Avoid using character buffers when constructing most directory
      objects: this approach was unwieldy and error-prone. Instead,
      build smartlists of strings, and concatenate them when done.


Changes in version 0.2.4.12-alpha - 2013-04-18
  Tor 0.2.4.12-alpha moves Tor forward on several fronts: it starts the
  process for lengthening the guard rotation period, makes directory
  authority opinions in the consensus a bit less gameable, makes socks5
  username/password circuit isolation actually work, and fixes a wide
  variety of other issues.

  o Major features:
    - Raise the default time that a client keeps an entry guard from
      "1-2 months" to "2-3 months", as suggested by Tariq Elahi's WPES
      2012 paper. (We would make it even longer, but we need better client
      load balancing first.) Also, make the guard lifetime controllable
      via a new GuardLifetime torrc option and a GuardLifetime consensus
      parameter. Start of a fix for bug 8240; bugfix on 0.1.1.11-alpha.
    - Directory authorities now prefer using measured bandwidths to
      advertised ones when computing flags and thresholds. Resolves
      ticket 8273.
    - Directory authorities that have more than a threshold number
      of relays with measured bandwidths now treat relays with unmeasured
      bandwidths as having bandwidth 0. Resolves ticket 8435.

  o Major bugfixes (assert / resource use):
    - Avoid a bug where our response to TLS renegotiation under certain
      network conditions could lead to a busy-loop, with 100% CPU
      consumption. Fixes bug 5650; bugfix on 0.2.0.16-alpha.
    - Avoid an assertion when we discover that we'd like to write a cell
      onto a closing connection: just discard the cell. Fixes another
      case of bug 7350; bugfix on 0.2.4.4-alpha.

  o Major bugfixes (client-side privacy):
    - When we mark a circuit as unusable for new circuits, have it
      continue to be unusable for new circuits even if MaxCircuitDirtiness
      is increased too much at the wrong time, or the system clock jumps
      backwards. Fixes bug 6174; bugfix on 0.0.2pre26.
    - If ClientDNSRejectInternalAddresses ("do not believe DNS queries
      which have resolved to internal addresses") is set, apply that
      rule to IPv6 as well. Fixes bug 8475; bugfix on 0.2.0.7-alpha.
    - When an exit relay rejects a stream with reason "exit policy", but
      we only know an exit policy summary (e.g. from the microdesc
      consensus) for it, do not mark the relay as useless for all exiting.
      Instead, mark just the circuit as unsuitable for that particular
      address. Fixes part of bug 7582; bugfix on 0.2.3.2-alpha.
    - Allow applications to get proper stream isolation with
      IsolateSOCKSAuth. Many SOCKS5 clients that want to offer
      username/password authentication also offer "no authentication". Tor
      had previously preferred "no authentication", so the applications
      never actually sent Tor their auth details. Now Tor selects
      username/password authentication if it's offered. You can disable
      this behavior on a per-SOCKSPort basis via PreferSOCKSNoAuth. Fixes
      bug 8117; bugfix on 0.2.3.3-alpha.

  o Major bugfixes (other):
    - When unable to find any working directory nodes to use as a
      directory guard, give up rather than adding the same non-working
      nodes to the directory guard list over and over. Fixes bug 8231;
      bugfix on 0.2.4.8-alpha.

  o Minor features:
    - Reject as invalid most directory objects containing a NUL.
      Belt-and-suspender fix for bug 8037.
    - In our testsuite, create temporary directories with a bit more
      entropy in their name to make name collisions less likely. Fixes
      bug 8638.
    - Add CACHED keyword to ADDRMAP events in the control protocol
      to indicate whether a DNS result will be cached or not. Resolves
      ticket 8596.
    - Update to the April 3 2013 Maxmind GeoLite Country database.

  o Minor features (build):
    - Detect and reject attempts to build Tor with threading support
      when OpenSSL has been compiled without threading support.
      Fixes bug 6673.
    - Clarify that when autoconf is checking for nacl, it is checking
      specifically for nacl with a fast curve25519 implementation.
      Fixes bug 8014.
    - Warn if building on a platform with an unsigned time_t: there
      are too many places where Tor currently assumes that time_t can
      hold negative values. We'd like to fix them all, but probably
      some will remain.

  o Minor bugfixes (build):
    - Fix some bugs in tor-fw-helper-natpmp when trying to build and
      run it on Windows. More bugs likely remain. Patch from Gisle Vanem.
      Fixes bug 7280; bugfix on 0.2.3.1-alpha.
    - Add the old src/or/micro-revision.i filename to CLEANFILES.
      On the off chance that somebody has one, it will go away as soon
      as they run "make clean". Fix for bug 7143; bugfix on 0.2.4.1-alpha.
    - Build Tor correctly on 32-bit platforms where the compiler can build
      but not run code using the "uint128_t" construction. Fixes bug 8587;
      bugfix on 0.2.4.8-alpha.
    - Fix compilation warning with some versions of clang that would
      prefer the -Wswitch-enum compiler flag to warn about switch
      statements with missing enum values, even if those switch
      statements have a "default:" statement. Fixes bug 8598; bugfix
      on 0.2.4.10-alpha.

  o Minor bugfixes (protocol):
    - Fix the handling of a TRUNCATE cell when it arrives while the
      circuit extension is in progress. Fixes bug 7947; bugfix on 0.0.7.1.
    - Fix a misframing issue when reading the version numbers in a
      VERSIONS cell. Previously we would recognize [00 01 00 02] as
      'version 1, version 2, and version 0x100', when it should have
      only included versions 1 and 2. Fixes bug 8059; bugfix on
      0.2.0.10-alpha. Reported pseudonymously.
    - Make the format and order of STREAM events for DNS lookups
      consistent among the various ways to launch DNS lookups. Fixes
      bug 8203; bugfix on 0.2.0.24-rc. Patch by "Desoxy."
    - Correct our check for which versions of Tor support the EXTEND2
      cell. We had been willing to send it to Tor 0.2.4.7-alpha and
      later, when support was really added in version 0.2.4.8-alpha.
      Fixes bug 8464; bugfix on 0.2.4.8-alpha.

  o Minor bugfixes (other):
    - Correctly store microdescriptors and extrainfo descriptors with
      an internal NUL byte. Fixes bug 8037; bugfix on 0.2.0.1-alpha.
      Bug reported by "cypherpunks".
    - Increase the width of the field used to remember a connection's
      link protocol version to two bytes. Harmless for now, since the
      only currently recognized versions are one byte long. Reported
      pseudonymously. Fixes bug 8062; bugfix on 0.2.0.10-alpha.
    - If the state file's path bias counts are invalid (presumably from a
      buggy Tor prior to 0.2.4.10-alpha), make them correct. Also add
      additional checks and log messages to the scaling of Path Bias
      counts, in case there still are remaining issues with scaling.
      Should help resolve bug 8235.
    - Eliminate several instances where we use "Nickname=ID" to refer to
      nodes in logs. Use "Nickname (ID)" instead. (Elsewhere, we still use
      "$ID=Nickname", which is also acceptable.) Fixes bug 7065. Bugfix
      on 0.2.3.21-rc, 0.2.4.5-alpha, 0.2.4.8-alpha, and 0.2.4.10-alpha.

  o Minor bugfixes (syscalls):
    - Always check the return values of functions fcntl() and
      setsockopt(). We don't believe these are ever actually failing in
      practice, but better safe than sorry. Also, checking these return
      values should please analysis tools like Coverity. Patch from
      'flupzor'. Fixes bug 8206; bugfix on all versions of Tor.
    - Use direct writes rather than stdio when building microdescriptor
      caches, in an attempt to mitigate bug 8031, or at least make it
      less common.

  o Minor bugfixes (config):
    - When rejecting a configuration because we were unable to parse a
      quoted string, log an actual error message. Fixes bug 7950; bugfix
      on 0.2.0.16-alpha.
    - Behave correctly when the user disables LearnCircuitBuildTimeout
      but doesn't tell us what they would like the timeout to be. Fixes
      bug 6304; bugfix on 0.2.2.14-alpha.
    - When autodetecting the number of CPUs, use the number of available
      CPUs in preference to the number of configured CPUs. Inform the
      user if this reduces the number of available CPUs. Fixes bug 8002;
      bugfix on 0.2.3.1-alpha.
    - Make it an error when you set EntryNodes but disable UseGuardNodes,
      since it will (surprisingly to some users) ignore EntryNodes. Fixes
      bug 8180; bugfix on 0.2.3.11-alpha.
    - Allow TestingTorNetworks to override the 4096-byte minimum for
      the Fast threshold. Otherwise they can't bootstrap until they've
      observed more traffic. Fixes bug 8508; bugfix on 0.2.4.10-alpha.
    - Fix some logic errors when the user manually overrides the
      PathsNeededToBuildCircuits option in torrc. Fixes bug 8599; bugfix
      on 0.2.4.10-alpha.

  o Minor bugfixes (log messages to help diagnose bugs):
    - If we fail to free a microdescriptor because of bug 7164, log
      the filename and line number from which we tried to free it.
    - Add another diagnostic to the heartbeat message: track and log
      overhead that TLS is adding to the data we write. If this is
      high, we are sending too little data to SSL_write at a time.
      Diagnostic for bug 7707.
    - Add more detail to a log message about relaxed timeouts, to help
      track bug 7799.
    - Warn more aggressively when flushing microdescriptors to a
      microdescriptor cache fails, in an attempt to mitigate bug 8031,
      or at least make it more diagnosable.
    - Improve debugging output to help track down bug 8185 ("Bug:
      outgoing relay cell has n_chan==NULL. Dropping.")
    - Log the purpose of a path-bias testing circuit correctly.
      Improves a log message from bug 8477; bugfix on 0.2.4.8-alpha.

  o Minor bugfixes (0.2.4.x log messages that were too noisy):
    - Don't attempt to relax the timeout of already opened 1-hop circuits.
      They might never timeout. This should eliminate some/all cases of
      the relaxed timeout log message.
    - Use circuit creation time for network liveness evaluation. This
      should eliminate warning log messages about liveness caused
      by changes in timeout evaluation. Fixes bug 6572; bugfix on
      0.2.4.8-alpha.
    - Reduce a path bias length check from notice to info. The message
      is triggered when creating controller circuits. Fixes bug 8196;
      bugfix on 0.2.4.8-alpha.
    - Fix a path state issue that triggered a notice during relay startup.
      Fixes bug 8320; bugfix on 0.2.4.10-alpha.
    - Reduce occurrences of warns about circuit purpose in
      connection_ap_expire_building(). Fixes bug 8477; bugfix on
      0.2.4.11-alpha.

  o Minor bugfixes (pre-0.2.4.x log messages that were too noisy):
    - If we encounter a write failure on a SOCKS connection before we
      finish our SOCKS handshake, don't warn that we closed the
      connection before we could send a SOCKS reply. Fixes bug 8427;
      bugfix on 0.1.0.1-rc.
    - Correctly recognize that [::1] is a loopback address. Fixes
      bug 8377; bugfix on 0.2.1.3-alpha.
    - Fix a directory authority warn caused when we have a large amount
      of badexit bandwidth. Fixes bug 8419; bugfix on 0.2.2.10-alpha.
    - Don't log inappropriate heartbeat messages when hibernating: a
      hibernating node is _expected_ to drop out of the consensus,
      decide it isn't bootstrapped, and so forth. Fixes bug 7302;
      bugfix on 0.2.3.1-alpha.
    - Don't complain about bootstrapping problems while hibernating.
      These complaints reflect a general code problem, but not one
      with any problematic effects (no connections are actually
      opened). Fixes part of bug 7302; bugfix on 0.2.3.2-alpha.

  o Documentation fixes:
    - Update tor-fw-helper.1.txt and tor-fw-helper.c to make option
      names match. Fixes bug 7768.
    - Make the torify manpage no longer refer to tsocks; torify hasn't
      supported tsocks since 0.2.3.14-alpha.
    - Make the tor manpage no longer reference tsocks.
    - Fix the GeoIPExcludeUnknown documentation to refer to
      ExcludeExitNodes rather than the currently nonexistent
      ExcludeEntryNodes. Spotted by "hamahangi" on tor-talk.

  o Removed files:
    - The tor-tsocks.conf is no longer distributed or installed. We
      recommend that tsocks users use torsocks instead. Resolves
      ticket 8290.


Changes in version 0.2.4.11-alpha - 2013-03-11
  Tor 0.2.4.11-alpha makes relay measurement by directory authorities
  more robust, makes hidden service authentication work again, and
  resolves a DPI fingerprint for Tor's SSL transport.

  o Major features (directory authorities):
    - Directory authorities now support a new consensus method (17)
      where they cap the published bandwidth of servers for which
      insufficient bandwidth measurements exist. Fixes part of bug 2286.
    - Directory authorities that set "DisableV2DirectoryInfo_ 1" no longer
      serve any v2 directory information. Now we can test disabling the
      old deprecated v2 directory format, and see whether doing so has
      any effect on network load. Begins to fix bug 6783.
    - Directory authorities now include inside each vote a statement of
      the performance thresholds they used when assigning flags.
      Implements ticket 8151.

  o Major bugfixes (directory authorities):
    - Stop marking every relay as having been down for one hour every
      time we restart a directory authority. These artificial downtimes
      were messing with our Stable and Guard flag calculations. Fixes
      bug 8218 (introduced by the fix for 1035). Bugfix on 0.2.2.23-alpha.

  o Major bugfixes (hidden services):
    - Allow hidden service authentication to succeed again. When we
      refactored the hidden service introduction code back
      in 0.2.4.1-alpha, we didn't update the code that checks
      whether authentication information is present, causing all
      authentication checks to return "false". Fix for bug 8207; bugfix
      on 0.2.4.1-alpha. Found by Coverity; this is CID 718615.

  o Minor features (relays, bridges):
    - Make bridge relays check once a minute for whether their IP
      address has changed, rather than only every 15 minutes. Resolves
      bugs 1913 and 1992.
    - Refactor resolve_my_address() so it returns the method by which we
      decided our public IP address (explicitly configured, resolved from
      explicit hostname, guessed from interfaces, learned by gethostname).
      Now we can provide more helpful log messages when a relay guesses
      its IP address incorrectly (e.g. due to unexpected lines in
      /etc/hosts). Resolves ticket 2267.
    - Teach bridge-using clients to avoid 0.2.2 bridges when making
      microdescriptor-related dir requests, and only fall back to normal
      descriptors if none of their bridges can handle microdescriptors
      (as opposed to the fix in ticket 4013, which caused them to fall
      back to normal descriptors if *any* of their bridges preferred
      them). Resolves ticket 4994.
    - Randomize the lifetime of our SSL link certificate, so censors can't
      use the static value for filtering Tor flows. Resolves ticket 8443;
      related to ticket 4014 which was included in 0.2.2.33.
    - Support a new version of the link protocol that allows 4-byte circuit
      IDs. Previously, circuit IDs were limited to 2 bytes, which presented
      a possible resource exhaustion issue. Closes ticket 7351; implements
      proposal 214.

  o Minor features (portability):
    - Tweak the curve25519-donna*.c implementations to tolerate systems
      that lack stdint.h. Fixes bug 3894; bugfix on 0.2.4.8-alpha.
    - Use Ville Laurikari's implementation of AX_CHECK_SIGN() to determine
      the signs of types during autoconf. This is better than our old
      approach, which didn't work when cross-compiling.
    - Detect the sign of enum values, rather than assuming that MSC is the
      only compiler where enum types are all signed. Fixes bug 7727;
      bugfix on 0.2.4.10-alpha.

  o Minor features (other):
    - Say "KBytes" rather than "KB" in the man page (for various values
      of K), to further reduce confusion about whether Tor counts in
      units of memory or fractions of units of memory. Resolves ticket 7054.
    - Clear the high bit on curve25519 public keys before passing them to
      our backend, in case we ever wind up using a backend that doesn't do
      so itself. If we used such a backend, and *didn't* clear the high bit,
      we could wind up in a situation where users with such backends would
      be distinguishable from users without. Fixes bug 8121; bugfix on
      0.2.4.8-alpha.
    - Update to the March 6 2013 Maxmind GeoLite Country database.

  o Minor bugfixes (clients):
    - When we receive a RELAY_END cell with the reason DONE, or with no
      reason, before receiving a RELAY_CONNECTED cell, report the SOCKS
      status as "connection refused". Previously we reported these cases
      as success but then immediately closed the connection. Fixes bug
      7902; bugfix on 0.1.0.1-rc. Reported by "oftc_must_be_destroyed".
    - Downgrade an assertion in connection_ap_expire_beginning to an
      LD_BUG message. The fix for bug 8024 should prevent this message
      from displaying, but just in case, a warn that we can diagnose
      is better than more assert crashes. Fixes bug 8065; bugfix on
      0.2.4.8-alpha.
    - Lower path use bias thresholds to .80 for notice and .60 for warn.
      Also make the rate limiting flags for the path use bias log messages
      independent from the original path bias flags. Fixes bug 8161;
      bugfix on 0.2.4.10-alpha.

  o Minor bugfixes (relays):
    - Stop trying to resolve our hostname so often (e.g. every time we
      think about doing a directory fetch). Now we reuse the cached
      answer in some cases. Fixes bugs 1992 (bugfix on 0.2.0.20-rc)
      and 2410 (bugfix on 0.1.2.2-alpha).
    - Stop sending a stray "(null)" in some cases for the server status
      "EXTERNAL_ADDRESS" controller event. Resolves bug 8200; bugfix
      on 0.1.2.6-alpha.
    - When choosing which stream on a formerly stalled circuit to wake
      first, make better use of the platform's weak RNG. Previously,
      we had been using the % ("modulo") operator to try to generate a
      1/N chance of picking each stream, but this behaves badly with
      many platforms' choice of weak RNG. Fixes bug 7801; bugfix on
      0.2.2.20-alpha.
    - Use our own weak RNG when we need a weak RNG. Windows's rand() and
      Irix's random() only return 15 bits; Solaris's random() returns more
      bits but its RAND_MAX says it only returns 15, and so on. Motivated
      by the fix for bug 7801; bugfix on 0.2.2.20-alpha.

  o Minor bugfixes (directory authorities):
    - Directory authorities now use less space when formatting identical
      microdescriptor lines in directory votes. Fixes bug 8158; bugfix
      on 0.2.4.1-alpha.

  o Minor bugfixes (memory leaks spotted by Coverity -- bug 7816):
    - Avoid leaking memory if we fail to compute a consensus signature
      or we generate a consensus we can't parse. Bugfix on 0.2.0.5-alpha.
    - Fix a memory leak when receiving headers from an HTTPS proxy. Bugfix
      on 0.2.1.1-alpha.
    - Fix a memory leak during safe-cookie controller authentication.
      Bugfix on 0.2.3.13-alpha.
    - Avoid memory leak of IPv6 policy content if we fail to format it into
      a router descriptor. Bugfix on 0.2.4.7-alpha.

  o Minor bugfixes (other code correctness issues):
    - Avoid a crash if we fail to generate an extrainfo descriptor.
      Fixes bug 8208; bugfix on 0.2.3.16-alpha. Found by Coverity;
      this is CID 718634.
    - When detecting the largest possible file descriptor (in order to
      close all file descriptors when launching a new program), actually
      use _SC_OPEN_MAX. The old code for doing this was very, very broken.
      Fixes bug 8209; bugfix on 0.2.3.1-alpha. Found by Coverity; this
      is CID 743383.
    - Fix a copy-and-paste error when adding a missing A1 to a routerset
      because of GeoIPExcludeUnknown. Fix for Coverity CID 980650.
      Bugfix on 0.2.4.10-alpha.
    - Fix an impossible-to-trigger integer overflow when estimating how
      long our onionskin queue would take. (This overflow would require us
      to accept 4 million onionskins before processing 100 of them.) Fixes
      bug 8210; bugfix on 0.2.4.10-alpha.

  o Code simplification and refactoring:
    - Add a wrapper function for the common "log a message with a
      rate-limit" case.


Changes in version 0.2.4.10-alpha - 2013-02-04
  Tor 0.2.4.10-alpha adds defenses at the directory authority level from
  certain attacks that flood the network with relays; changes the queue
  for circuit create requests from a sized-based limit to a time-based
  limit; resumes building with MSVC on Windows; and fixes a wide variety
  of other issues.

  o Major bugfixes (directory authority):
    - When computing directory thresholds, ignore any rejected-as-sybil
      nodes during the computation so that they can't influence Fast,
      Guard, etc. (We should have done this for proposal 109.) Fixes
      bug 8146.
    - When marking a node as a likely sybil, reset its uptime metrics
      to zero, so that it cannot time towards getting marked as Guard,
      Stable, or HSDir. (We should have done this for proposal 109.) Fixes
      bug 8147.

  o Major bugfixes:
    - When a TLS write is partially successful but incomplete, remember
      that the flushed part has been flushed, and notice that bytes were
      actually written. Reported and fixed pseudonymously. Fixes bug
      7708; bugfix on Tor 0.1.0.5-rc.
    - Reject bogus create and relay cells with 0 circuit ID or 0 stream
      ID: these could be used to create unexpected streams and circuits
      which would count as "present" to some parts of Tor but "absent"
      to others, leading to zombie circuits and streams or to a bandwidth
      denial-of-service. Fixes bug 7889; bugfix on every released version
      of Tor. Reported by "oftc_must_be_destroyed".
    - Rename all macros in our local copy of queue.h to begin with "TOR_".
      This change seems the only good way to permanently prevent conflicts
      with queue.h on various operating systems. Fixes bug 8107; bugfix
      on 0.2.4.6-alpha.

  o Major features (relay):
    - Instead of limiting the number of queued onionskins (aka circuit
      create requests) to a fixed, hard-to-configure number, we limit
      the size of the queue based on how many we expect to be able to
      process in a given amount of time. We estimate the time it will
      take to process an onionskin based on average processing time
      of previous onionskins. Closes ticket 7291. You'll never have to
      configure MaxOnionsPending again.

  o Major features (portability):
    - Resume building correctly with MSVC and Makefile.nmake. This patch
      resolves numerous bugs and fixes reported by ultramage, including
      7305, 7308, 7309, 7310, 7312, 7313, 7315, 7316, and 7669.
    - Make the ntor and curve25519 code build correctly with MSVC.
      Fix on 0.2.4.8-alpha.

  o Minor features:
    - When directory authorities are computing thresholds for flags,
      never let the threshold for the Fast flag fall below 4096
      bytes. Also, do not consider nodes with extremely low bandwidths
      when deciding thresholds for various directory flags. This change
      should raise our threshold for Fast relays, possibly in turn
      improving overall network performance; see ticket 1854. Resolves
      ticket 8145.
    - The Tor client now ignores sub-domain components of a .onion
      address. This change makes HTTP "virtual" hosting
      possible: http://foo.aaaaaaaaaaaaaaaa.onion/ and
      http://bar.aaaaaaaaaaaaaaaa.onion/ can be two different websites
      hosted on the same hidden service. Implements proposal 204.
    - We compute the overhead from passing onionskins back and forth to
      cpuworkers, and report it when dumping statistics in response to
      SIGUSR1. Supports ticket 7291.

  o Minor features (path selection):
    - When deciding whether we have enough descriptors to build circuits,
      instead of looking at raw relay counts, look at which fraction
      of (bandwidth-weighted) paths we're able to build. This approach
      keeps clients from building circuits if their paths are likely to
      stand out statistically. The default fraction of paths needed is
      taken from the consensus directory; you can override it with the
      new PathsNeededToBuildCircuits option. Fixes ticket 5956.
    - When any country code is listed in ExcludeNodes or ExcludeExitNodes,
      and we have GeoIP information, also exclude all nodes with unknown
      countries "??" and "A1". This behavior is controlled by the
      new GeoIPExcludeUnknown option: you can make such nodes always
      excluded with "GeoIPExcludeUnknown 1", and disable the feature
      with "GeoIPExcludeUnknown 0". Setting "GeoIPExcludeUnknown auto"
      gets you the default behavior. Implements feature 7706.
    - Path Use Bias: Perform separate accounting for successful circuit
      use. Keep separate statistics on stream attempt rates versus stream
      success rates for each guard. Provide configurable thresholds to
      determine when to emit log messages or disable use of guards that
      fail too many stream attempts. Resolves ticket 7802.

  o Minor features (log messages):
    - When learning a fingerprint for a bridge, log its corresponding
      transport type. Implements ticket 7896.
    - Improve the log message when "Bug/attack: unexpected sendme cell
      from client" occurs, to help us track bug 8093.

  o Minor bugfixes:
    - Remove a couple of extraneous semicolons that were upsetting the
      cparser library. Patch by Christian Grothoff. Fixes bug 7115;
      bugfix on 0.2.2.1-alpha.
    - Remove a source of rounding error during path bias count scaling;
      don't count cannibalized circuits as used for path bias until we
      actually try to use them; and fix a circuit_package_relay_cell()
      warning message about n_chan==NULL. Fixes bug 7802.
    - Detect nacl when its headers are in a nacl/ subdirectory. Also,
      actually link against nacl when we're configured to use it. Fixes
      bug 7972; bugfix on 0.2.4.8-alpha.
    - Compile correctly with the --disable-curve25519 option. Fixes
      bug 8153; bugfix on 0.2.4.8-alpha.

  o Build improvements:
    - Do not report status verbosely from autogen.sh unless the -v flag
      is specified. Fixes issue 4664. Patch from Onizuka.
    - Replace all calls to snprintf() outside of src/ext with
      tor_snprintf(). Also remove the #define to replace snprintf with
      _snprintf on Windows; they have different semantics, and all of
      our callers should be using tor_snprintf() anyway. Fixes bug 7304.
    - Try to detect if we are ever building on a platform where
      memset(...,0,...) does not set the value of a double to 0.0. Such
      platforms are permitted by the C standard, though in practice
      they're pretty rare (since IEEE 754 is nigh-ubiquitous). We don't
      currently support them, but it's better to detect them and fail
      than to perform erroneously.

  o Removed features:
    - Stop exporting estimates of v2 and v3 directory traffic shares
      in extrainfo documents. They were unneeded and sometimes inaccurate.
      Also stop exporting any v2 directory request statistics. Resolves
      ticket 5823.
    - Drop support for detecting and warning about versions of Libevent
      before 1.3e. Nothing reasonable ships with them any longer;
      warning the user about them shouldn't be needed. Resolves ticket
      6826.

  o Code simplifications and refactoring:
    - Rename "isin" functions to "contains", for grammar. Resolves
      ticket 5285.
    - Rename Tor's logging function log() to tor_log(), to avoid conflicts
      with the natural logarithm function from the system libm. Resolves
      ticket 7599.


Changes in version 0.2.4.9-alpha - 2013-01-15
  Tor 0.2.4.9-alpha provides a quick fix to make the new ntor handshake
  work more robustly.

  o Major bugfixes:
    - Fix backward compatibility logic when receiving an embedded ntor
      handshake tunneled in a CREATE cell. This clears up the "Bug:
      couldn't format CREATED cell" warning. Fixes bug 7959; bugfix
      on 0.2.4.8-alpha.


Changes in version 0.2.4.8-alpha - 2013-01-14
  Tor 0.2.4.8-alpha introduces directory guards to reduce user enumeration
  risks, adds a new stronger and faster circuit handshake, and offers
  stronger and faster link encryption when both sides support it.

  o Major features:
    - Preliminary support for directory guards (proposal 207): when
      possible, clients now use their entry guards for non-anonymous
      directory requests. This can help prevent client enumeration. Note
      that this behavior only works when we have a usable consensus
      directory, and when options about what to download are more or less
      standard. In the future we should re-bootstrap from our guards,
      rather than re-bootstrapping from the preconfigured list of
      directory sources that ships with Tor. Resolves ticket 6526.
    - Tor relays and clients now support a better CREATE/EXTEND cell
      format, allowing the sender to specify multiple address, identity,
      and handshake types. Implements Robert Ransom's proposal 200;
      closes ticket 7199.

  o Major features (new circuit handshake):
    - Tor now supports a new circuit extension handshake designed by Ian
      Goldberg, Douglas Stebila, and Berkant Ustaoglu. Our original
      circuit extension handshake, later called "TAP", was a bit slow
      (especially on the relay side), had a fragile security proof, and
      used weaker keys than we'd now prefer. The new circuit handshake
      uses Dan Bernstein's "curve25519" elliptic-curve Diffie-Hellman
      function, making it significantly more secure than the older
      handshake, and significantly faster. Tor can use one of two built-in
      pure-C curve25519-donna implementations by Adam Langley, or it
      can link against the "nacl" library for a tuned version if present.

      The built-in version is very fast for 64-bit systems when building
      with GCC. The built-in 32-bit version is still faster than the
      old TAP protocol, but using libnacl is better on most such hosts.

      Clients don't currently use this protocol by default, since
      comparatively few clients support it so far. To try it, set
      UseNTorHandshake to 1.

      Implements proposal 216; closes ticket 7202.

  o Major features (better link encryption):
    - Relays can now enable the ECDHE TLS ciphersuites when available
      and appropriate. These ciphersuites let us negotiate forward-secure
      TLS secret keys more safely and more efficiently than with our
      previous use of Diffie-Hellman modulo a 1024-bit prime. By default,
      public relays prefer the (faster) P224 group, and bridges prefer
      the (more common) P256 group; you can override this with the
      TLSECGroup option.

      Enabling these ciphers was a little tricky, since for a long time,
      clients had been claiming to support them without actually doing
      so, in order to foil fingerprinting. But with the client-side
      implementation of proposal 198 in 0.2.3.17-beta, clients can now
      match the ciphers from recent Firefox versions *and* list the
      ciphers they actually mean, so relays can believe such clients
      when they advertise ECDHE support in their TLS ClientHello messages.

      This feature requires clients running 0.2.3.17-beta or later,
      and requires both sides to be running OpenSSL 1.0.0 or later
      with ECC support. OpenSSL 1.0.1, with the compile-time option
      "enable-ec_nistp_64_gcc_128", is highly recommended.

      Implements the relay side of proposal 198; closes ticket 7200.

  o Major bugfixes:
    - Avoid crashing when, as a relay without IPv6-exit support, a
      client insists on getting an IPv6 address or nothing. Fixes bug
      7814; bugfix on 0.2.4.7-alpha.

  o Minor features:
    - Improve circuit build timeout handling for hidden services.
      In particular: adjust build timeouts more accurately depending
      upon the number of hop-RTTs that a particular circuit type
      undergoes. Additionally, launch intro circuits in parallel
      if they timeout, and take the first one to reply as valid.
    - Work correctly on Unix systems where EAGAIN and EWOULDBLOCK are
      separate error codes; or at least, don't break for that reason.
      Fixes bug 7935. Reported by "oftc_must_be_destroyed".
    - Update to the January 2 2013 Maxmind GeoLite Country database.

  o Minor features (testing):
    - Add benchmarks for DH (1024-bit multiplicative group) and ECDH
      (P-256) Diffie-Hellman handshakes to src/or/bench.
    - Add benchmark functions to test onion handshake performance.

  o Minor features (path bias detection):
    - Alter the Path Bias log messages to be more descriptive in terms
      of reporting timeouts and other statistics.
    - Create three levels of Path Bias log messages, as opposed to just
      two. These are configurable via consensus as well as via the torrc
      options PathBiasNoticeRate, PathBiasWarnRate, PathBiasExtremeRate.
      The default values are 0.70, 0.50, and 0.30 respectively.
    - Separate the log message levels from the decision to drop guards,
      which also is available via torrc option PathBiasDropGuards.
      PathBiasDropGuards still defaults to 0 (off).
    - Deprecate PathBiasDisableRate in favor of PathBiasDropGuards
      in combination with PathBiasExtremeRate.
    - Increase the default values for PathBiasScaleThreshold and
      PathBiasCircThreshold from (200, 20) to (300, 150).
    - Add in circuit usage accounting to path bias. If we try to use a
      built circuit but fail for any reason, it counts as path bias.
      Certain classes of circuits where the adversary gets to pick your
      destination node are exempt from this accounting. Usage accounting
      can be specifically disabled via consensus parameter or torrc.
    - Convert all internal path bias state to double-precision floating
      point, to avoid roundoff error and other issues.
    - Only record path bias information for circuits that have completed
      *two* hops. Assuming end-to-end tagging is the attack vector, this
      makes us more resilient to ambient circuit failure without any
      detection capability loss.

  o Minor bugfixes (log messages):
    - Rate-limit the "No circuits are opened. Relaxed timeout for a
      circuit with channel state open..." message to once per hour to
      keep it from filling the notice logs. Mitigates bug 7799 but does
      not fix the underlying cause. Bugfix on 0.2.4.7-alpha.
    - Avoid spurious warnings when configuring multiple client ports of
      which only some are nonlocal. Previously, we had claimed that some
      were nonlocal when in fact they weren't. Fixes bug 7836; bugfix on
      0.2.3.3-alpha.

  o Code simplifications and refactoring:
    - Get rid of a couple of harmless clang warnings, where we compared
      enums to ints. These warnings are newly introduced in clang 3.2.
    - Split the onion.c file into separate modules for the onion queue
      and the different handshakes it supports.
    - Remove the marshalling/unmarshalling code for sending requests to
      cpuworkers over a socket, and instead just send structs. The
      recipient will always be the same Tor binary as the sender, so
      any encoding is overkill.


Changes in version 0.2.4.7-alpha - 2012-12-24
  Tor 0.2.4.7-alpha introduces a new approach to providing fallback
  directory mirrors for more robust bootstrapping; fixes more issues where
  clients with changing network conditions refuse to make any circuits;
  adds initial support for exiting to IPv6 addresses; resumes being able
  to update our GeoIP database, and includes the geoip6 file this time;
  turns off the client-side DNS cache by default due to privacy risks;
  and fixes a variety of other issues.

  o Major features (client resilience):
    - Add a new "FallbackDir" torrc option to use when we can't use
      a directory mirror from the consensus (either because we lack a
      consensus, or because they're all down). Currently, all authorities
      are fallbacks by default, and there are no other default fallbacks,
      but that will change. This option will allow us to give clients a
      longer list of servers to try to get a consensus from when first
      connecting to the Tor network, and thereby reduce load on the
      directory authorities. Implements proposal 206, "Preconfigured
      directory sources for bootstrapping". We also removed the old
      "FallbackNetworkstatus" option, since we never got it working well
      enough to use it. Closes bug 572.
    - If we have no circuits open, use a relaxed timeout (the
      95-percentile cutoff) until a circuit succeeds. This heuristic
      should allow Tor to succeed at building circuits even when the
      network connection drastically changes. Should help with bug 3443.

  o Major features (IPv6):
    - Relays can now exit to IPv6 addresses: make sure that you have IPv6
      connectivity, then set the IPv6Exit flag to 1. Also make sure your
      exit policy reads as you would like: the address * applies to all
      address families, whereas *4 is IPv4 address only, and *6 is IPv6
      addresses only. On the client side, you'll need to wait until the
      authorities have upgraded, wait for enough exits to support IPv6,
      apply the "IPv6Traffic" flag to a SocksPort, and use Socks5. Closes
      ticket 5547, implements proposal 117 as revised in proposal 208.

      We DO NOT recommend that clients with actual anonymity needs start
      using IPv6 over Tor yet, since not enough exits support it yet.

  o Major features (geoip database):
    - Maxmind began labelling Tor relays as being in country "A1",
      which breaks by-country node selection inside Tor. Now we use a
      script to replace "A1" ("Anonymous Proxy") entries in our geoip
      file with real country codes. This script fixes about 90% of "A1"
      entries automatically and uses manual country code assignments to
      fix the remaining 10%. See src/config/README.geoip for details.
      Fixes bug 6266. Also update to the December 5 2012 Maxmind GeoLite
      Country database, as modified above.

  o Major bugfixes (client-side DNS):
    - Turn off the client-side DNS cache by default. Updating and using
      the DNS cache is now configurable on a per-client-port
      level. SOCKSPort, DNSPort, etc lines may now contain
      {No,}Cache{IPv4,IPv6,}DNS lines to indicate that we shouldn't
      cache these types of DNS answers when we receive them from an
      exit node in response to an application request on this port, and
      {No,}UseCached{IPv4,IPv6,DNS} lines to indicate that if we have
      cached DNS answers of these types, we shouldn't use them. It's
      potentially risky to use cached DNS answers at the client, since
      doing so can indicate to one exit what answers we've gotten
      for DNS lookups in the past. With IPv6, this becomes especially
      problematic. Using cached DNS answers for requests on the same
      circuit would present less linkability risk, since all traffic
      on a circuit is already linkable, but it would also provide
      little performance benefit: the exit node caches DNS replies
      too. Implements a simplified version of Proposal 205. Implements
      ticket 7570.

  o Major bugfixes (other):
    - Alter circuit build timeout measurement to start at the point
      where we begin the CREATE/CREATE_FAST step (as opposed to circuit
      initialization). This should make our timeout measurements more
      uniform. Previously, we were sometimes including ORconn setup time
      in our circuit build time measurements. Should resolve bug 3443.
    - Fix an assertion that could trigger in hibernate_go_dormant() when
      closing an or_connection_t: call channel_mark_for_close() rather
      than connection_mark_for_close(). Fixes bug 7267. Bugfix on
      0.2.4.4-alpha.
    - Include the geoip6 IPv6 GeoIP database in the tarball. Fixes bug
      7655; bugfix on 0.2.4.6-alpha.

  o Minor features:
    - Add a new torrc option "ServerTransportListenAddr" to let bridge
      operators select the address where their pluggable transports will
      listen for connections. Resolves ticket 7013.
    - Allow an optional $ before the node identity digest in the
      controller command GETINFO ns/id/<identity>, for consistency with
      md/id/<identity> and desc/id/<identity>. Resolves ticket 7059.
    - Log packaged cell fullness as part of the heartbeat message.
      Diagnosis to try to determine the extent of bug 7743.

  o Minor features (IPv6):
    - AutomapHostsOnResolve now supports IPv6 addresses. By default, we
      prefer to hand out virtual IPv6 addresses, since there are more of
      them and we can't run out. To override this behavior and make IPv4
      addresses preferred, set NoPreferIPv6Automap on whatever SOCKSPort
      or DNSPort you're using for resolving. Implements ticket 7571.
    - AutomapHostsOnResolve responses are now randomized, to avoid
      annoying situations where Tor is restarted and applications
      connect to the wrong addresses.
    - Never try more than 1000 times to pick a new virtual address when
      AutomapHostsOnResolve is set. That's good enough so long as we
      aren't close to handing out our entire virtual address space;
      if you're getting there, it's best to switch to IPv6 virtual
      addresses anyway.

  o Minor bugfixes:
    - The ADDRMAP command can no longer generate an ill-formed error
      code on a failed MAPADDRESS. It now says "internal" rather than
      an English sentence fragment with spaces in the middle. Bugfix on
      Tor 0.2.0.19-alpha.
    - Fix log messages and comments to avoid saying "GMT" when we mean
      "UTC". Fixes bug 6113.
    - Compile on win64 using mingw64. Fixes bug 7260; patches from
      "yayooo".
    - Fix a crash when debugging unit tests on Windows: deallocate a
      shared library with FreeLibrary, not CloseHandle. Fixes bug 7306;
      bugfix on 0.2.2.17-alpha. Reported by "ultramage".

  o Renamed options:
    - The DirServer option is now DirAuthority, for consistency with
      current naming patterns. You can still use the old DirServer form.

  o Code simplification and refactoring:
    - Move the client-side address-map/virtual-address/DNS-cache code
      out of connection_edge.c into a new addressmap.c module.
    - Remove unused code for parsing v1 directories and "running routers"
      documents. Fixes bug 6887.


Changes in version 0.2.3.25 - 2012-11-19
  The Tor 0.2.3 release series is dedicated to the memory of Len "rabbi"
  Sassaman (1980-2011), a long-time cypherpunk, anonymity researcher,
  Mixmaster maintainer, Pynchon Gate co-designer, CodeCon organizer,
  programmer, and friend. Unstinting in his dedication to the cause of
  freedom, he inspired and helped many of us as we began our work on
  anonymity, and inspires us still. Please honor his memory by writing
  software to protect people's freedoms, and by helping others to do so.

  Tor 0.2.3.25, the first stable release in the 0.2.3 branch, features
  significantly reduced directory overhead (via microdescriptors),
  enormous crypto performance improvements for fast relays on new
  enough hardware, a new v3 TLS handshake protocol that can better
  resist fingerprinting, support for protocol obfuscation plugins (aka
  pluggable transports), better scalability for hidden services, IPv6
  support for bridges, performance improvements like allowing clients
  to skip the first round-trip on the circuit ("optimistic data") and
  refilling token buckets more often, a new "stream isolation" design
  to isolate different applications on different circuits, and many
  stability, security, and privacy fixes.

  o Major bugfixes:
    - Tor tries to wipe potentially sensitive data after using it, so
      that if some subsequent security failure exposes Tor's memory,
      the damage will be limited. But we had a bug where the compiler
      was eliminating these wipe operations when it decided that the
      memory was no longer visible to a (correctly running) program,
      hence defeating our attempt at defense in depth. We fix that
      by using OpenSSL's OPENSSL_cleanse() operation, which a compiler
      is unlikely to optimize away. Future versions of Tor may use
      a less ridiculously heavy approach for this. Fixes bug 7352.
      Reported in an article by Andrey Karpov.

  o Minor bugfixes:
    - Fix a harmless bug when opting against publishing a relay descriptor
      because DisableNetwork is set. Fixes bug 7464; bugfix on
      0.2.3.9-alpha.


Changes in version 0.2.4.6-alpha - 2012-11-13
  Tor 0.2.4.6-alpha fixes an assert bug that has been plaguing relays,
  makes our defense-in-depth memory wiping more reliable, and begins to
  count IPv6 addresses in bridge statistics,

  o Major bugfixes:
    - Fix an assertion failure that could occur when closing a connection
      with a spliced rendezvous circuit. Fix for bug 7212; bugfix on
      Tor 0.2.4.4-alpha.
    - Tor tries to wipe potentially sensitive data after using it, so
      that if some subsequent security failure exposes Tor's memory,
      the damage will be limited. But we had a bug where the compiler
      was eliminating these wipe operations when it decided that the
      memory was no longer visible to a (correctly running) program,
      hence defeating our attempt at defense in depth. We fix that
      by using OpenSSL's OPENSSL_cleanse() operation, which a compiler
      is unlikely to optimize away. Future versions of Tor may use
      a less ridiculously heavy approach for this. Fixes bug 7352.
      Reported in an article by Andrey Karpov.

  o Minor features:
    - Add GeoIP database for IPv6 addresses. The new config option
      is GeoIPv6File.
    - Bridge statistics now count bridge clients connecting over IPv6:
      bridge statistics files now list "bridge-ip-versions" and
      extra-info documents list "geoip6-db-digest". The control protocol
      "CLIENTS_SEEN" and "ip-to-country" queries now support IPv6. Initial
      implementation by "shkoo", addressing ticket 5055.

  o Minor bugfixes:
    - Warn when we are binding low ports when hibernation is enabled;
      previously we had warned when we were _advertising_ low ports with
      hibernation enabled. Fixes bug 7285; bugfix on 0.2.3.9-alpha.
    - Fix a harmless bug when opting against publishing a relay descriptor
      because DisableNetwork is set. Fixes bug 7464; bugfix on
      0.2.3.9-alpha.
    - Add warning message when a managed proxy dies during configuration.
      Fixes bug 7195; bugfix on 0.2.4.2-alpha.
    - Fix a linking error when building tor-fw-helper without miniupnp.
      Fixes bug 7235; bugfix on 0.2.4.2-alpha. Fix by Anthony G. Basile.
    - Check for closing an or_connection_t without going through correct
      channel functions; emit a warning and then call
      connection_or_close_for_error() so we don't assert as in bugs 7212
      and 7267.
    - Compile correctly on compilers without C99 designated initializer
      support. Fixes bug 7286; bugfix on 0.2.4.4-alpha.
    - Avoid a possible assert that can occur when channel_send_destroy() is
      called on a channel in CHANNEL_STATE_CLOSING, CHANNEL_STATE_CLOSED,
      or CHANNEL_STATE_ERROR when the Tor process is resumed after being
      blocked for a long interval. Fixes bug 7350; bugfix on 0.2.4.4-alpha.
    - Fix a memory leak on failing cases of channel_tls_process_certs_cell.
      Fixes bug 7422; bugfix on 0.2.4.4-alpha.

  o Code simplification and refactoring:
    - Start using OpenBSD's implementation of queue.h, so that we don't
      need to hand-roll our own pointer and list structures whenever we
      need them. (We can't rely on a sys/queue.h, since some operating
      systems don't have them, and the ones that do have them don't all
      present the same extensions.)


Changes in version 0.2.4.5-alpha - 2012-10-25
  Tor 0.2.4.5-alpha comes hard at the heels of 0.2.4.4-alpha, to fix
  two important security vulnerabilities that could lead to remotely
  triggerable relay crashes, fix a major bug that was preventing clients
  from choosing suitable exit nodes, and refactor some of our code.

  o Major bugfixes (security, also in 0.2.3.24-rc):
    - Fix a group of remotely triggerable assertion failures related to
      incorrect link protocol negotiation. Found, diagnosed, and fixed
      by "some guy from France". Fix for CVE-2012-2250; bugfix on
      0.2.3.6-alpha.
    - Fix a denial of service attack by which any directory authority
      could crash all the others, or by which a single v2 directory
      authority could crash everybody downloading v2 directory
      information. Fixes bug 7191; bugfix on 0.2.0.10-alpha.

  o Major bugfixes (also in 0.2.3.24-rc):
    - When parsing exit policy summaries from microdescriptors, we had
      previously been ignoring the last character in each one, so that
      "accept 80,443,8080" would be treated by clients as indicating
      a node that allows access to ports 80, 443, and 808. That would
      lead to clients attempting connections that could never work,
      and ignoring exit nodes that would support their connections. Now
      clients parse these exit policy summaries correctly. Fixes bug 7192;
      bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (also in 0.2.3.24-rc):
    - Clients now consider the ClientRejectInternalAddresses config option
      when using a microdescriptor consensus stanza to decide whether
      an exit relay would allow exiting to an internal address. Fixes
      bug 7190; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes:
    - Only disable TLS session ticket support when running as a TLS
      server. Now clients will blend better with regular Firefox
      connections. Fixes bug 7189; bugfix on Tor 0.2.3.23-rc.

  o Code simplification and refactoring:
    - Start using OpenBSD's implementation of queue.h (originally by
      Niels Provos).
    - Move the entry node code from circuitbuild.c to its own file.
    - Move the circuit build timeout tracking code from circuitbuild.c
      to its own file.


Changes in version 0.2.3.24-rc - 2012-10-25
  Tor 0.2.3.24-rc fixes two important security vulnerabilities that
  could lead to remotely triggerable relay crashes, and fixes
  a major bug that was preventing clients from choosing suitable exit
  nodes.

  o Major bugfixes (security):
    - Fix a group of remotely triggerable assertion failures related to
      incorrect link protocol negotiation. Found, diagnosed, and fixed
      by "some guy from France". Fix for CVE-2012-2250; bugfix on
      0.2.3.6-alpha.
    - Fix a denial of service attack by which any directory authority
      could crash all the others, or by which a single v2 directory
      authority could crash everybody downloading v2 directory
      information. Fixes bug 7191; bugfix on 0.2.0.10-alpha.

  o Major bugfixes:
    - When parsing exit policy summaries from microdescriptors, we had
      previously been ignoring the last character in each one, so that
      "accept 80,443,8080" would be treated by clients as indicating
      a node that allows access to ports 80, 443, and 808. That would
      lead to clients attempting connections that could never work,
      and ignoring exit nodes that would support their connections. Now
      clients parse these exit policy summaries correctly. Fixes bug 7192;
      bugfix on 0.2.3.1-alpha.

  o Minor bugfixes:
    - Clients now consider the ClientRejectInternalAddresses config option
      when using a microdescriptor consensus stanza to decide whether
      an exit relay would allow exiting to an internal address. Fixes
      bug 7190; bugfix on 0.2.3.1-alpha.


Changes in version 0.2.4.4-alpha - 2012-10-20
  Tor 0.2.4.4-alpha adds a new v3 directory authority, fixes a privacy
  vulnerability introduced by a change in OpenSSL, fixes a remotely
  triggerable assert, and adds new channel_t and circuitmux_t abstractions
  that will make it easier to test new connection transport and cell
  scheduling algorithms.

  o New directory authorities (also in 0.2.3.23-rc):
    - Add Faravahar (run by Sina Rabbani) as the ninth v3 directory
      authority. Closes ticket 5749.

  o Major bugfixes (security/privacy, also in 0.2.3.23-rc):
    - Disable TLS session tickets. OpenSSL's implementation was giving
      our TLS session keys the lifetime of our TLS context objects, when
      perfect forward secrecy would want us to discard anything that
      could decrypt a link connection as soon as the link connection
      was closed. Fixes bug 7139; bugfix on all versions of Tor linked
      against OpenSSL 1.0.0 or later. Found by Florent Daignière.
    - Discard extraneous renegotiation attempts once the V3 link
      protocol has been initiated. Failure to do so left us open to
      a remotely triggerable assertion failure. Fixes CVE-2012-2249;
      bugfix on 0.2.3.6-alpha. Reported by "some guy from France".

  o Internal abstraction features:
    - Introduce new channel_t abstraction between circuits and
      or_connection_t to allow for implementing alternate OR-to-OR
      transports. A channel_t is an abstract object which can either be a
      cell-bearing channel, which is responsible for authenticating and
      handshaking with the remote OR and transmitting cells to and from
      it, or a listening channel, which spawns new cell-bearing channels
      at the request of remote ORs. Implements part of ticket 6465.
    - Also new is the channel_tls_t subclass of channel_t, adapting it
      to the existing or_connection_t code. The V2/V3 protocol handshaking
      code which formerly resided in command.c has been moved below the
      channel_t abstraction layer and may be found in channeltls.c now.
      Implements the rest of ticket 6465.
    - Introduce new circuitmux_t storing the queue of circuits for
      a channel; this encapsulates and abstracts the queue logic and
      circuit selection policy, and allows the latter to be overridden
      easily by switching out a policy object. The existing EWMA behavior
      is now implemented as a circuitmux_policy_t. Resolves ticket 6816.

  o Required libraries:
    - Tor now requires OpenSSL 0.9.8 or later. OpenSSL 1.0.0 or later is
      strongly recommended.

  o Minor features:
    - Warn users who run hidden services on a Tor client with
      UseEntryGuards disabled that their hidden services will be
      vulnerable to http://freehaven.net/anonbib/#hs-attack06 (the
      attack which motivated Tor to support entry guards in the first
      place). Resolves ticket 6889.
    - Tor now builds correctly on Bitrig, an OpenBSD fork. Patch from
      dhill. Resolves ticket 6982.
    - Option OutboundBindAddress can be specified multiple times and
      accepts IPv6 addresses. Resolves ticket 6876.

  o Minor bugfixes (also in 0.2.3.23-rc):
    - Don't serve or accept v2 hidden service descriptors over a
      relay's DirPort. It's never correct to do so, and disabling it
      might make it more annoying to exploit any bugs that turn up in the
      descriptor-parsing code. Fixes bug 7149.
    - Fix two cases in src/or/transports.c where we were calling
      fmt_addr() twice in a parameter list. Bug found by David
      Fifield. Fixes bug 7014; bugfix on 0.2.3.9-alpha.
    - Fix memory leaks whenever we logged any message about the "path
      bias" detection. Fixes bug 7022; bugfix on 0.2.3.21-rc.
    - When relays refuse a "create" cell because their queue of pending
      create cells is too big (typically because their cpu can't keep up
      with the arrival rate), send back reason "resource limit" rather
      than reason "internal", so network measurement scripts can get a
      more accurate picture. Fixes bug 7037; bugfix on 0.1.1.11-alpha.

  o Minor bugfixes:
    - Command-line option "--version" implies "--quiet". Fixes bug 6997.
    - Free some more still-in-use memory at exit, to make hunting for
      memory leaks easier. Resolves bug 7029.
    - When a Tor client gets a "truncated" relay cell, the first byte of
      its payload specifies why the circuit was truncated. We were
      ignoring this 'reason' byte when tearing down the circuit, resulting
      in the controller not being told why the circuit closed. Now we
      pass the reason from the truncated cell to the controller. Bugfix
      on 0.1.2.3-alpha; fixes bug 7039.
    - Downgrade "Failed to hand off onionskin" messages to "debug"
      severity, since they're typically redundant with the "Your computer
      is too slow" messages. Fixes bug 7038; bugfix on 0.2.2.16-alpha.
    - Make clients running with IPv6 bridges connect over IPv6 again,
      even without setting new config options ClientUseIPv6 and
      ClientPreferIPv6ORPort. Fixes bug 6757; bugfix on 0.2.4.1-alpha.
    - Use square brackets around IPv6 addresses in numerous places
      that needed them, including log messages, HTTPS CONNECT proxy
      requests, TransportProxy statefile entries, and pluggable transport
      extra-info lines. Fixes bug 7011; patch by David Fifield.

  o Code refactoring and cleanup:
    - Source files taken from other packages now reside in src/ext;
      previously they were scattered around the rest of Tor.
    - Avoid use of reserved identifiers in our C code. The C standard
      doesn't like us declaring anything that starts with an
      underscore, so let's knock it off before we get in trouble. Fix
      for bug 1031; bugfix on the first Tor commit.


Changes in version 0.2.3.23-rc - 2012-10-20
  Tor 0.2.3.23-rc adds a new v3 directory authority, fixes a privacy
  vulnerability introduced by a change in OpenSSL, and fixes a variety
  of smaller bugs in preparation for the release.

  o New directory authorities:
    - Add Faravahar (run by Sina Rabbani) as the ninth v3 directory
      authority. Closes ticket 5749.

  o Major bugfixes (security/privacy):
    - Disable TLS session tickets. OpenSSL's implementation was giving
      our TLS session keys the lifetime of our TLS context objects, when
      perfect forward secrecy would want us to discard anything that
      could decrypt a link connection as soon as the link connection
      was closed. Fixes bug 7139; bugfix on all versions of Tor linked
      against OpenSSL 1.0.0 or later. Found by Florent Daignière.
    - Discard extraneous renegotiation attempts once the V3 link
      protocol has been initiated. Failure to do so left us open to
      a remotely triggerable assertion failure. Fixes CVE-2012-2249;
      bugfix on 0.2.3.6-alpha. Reported by "some guy from France".

  o Major bugfixes:
    - Fix a possible crash bug when checking for deactivated circuits
      in connection_or_flush_from_first_active_circuit(). Fixes bug 6341;
      bugfix on 0.2.2.7-alpha. Bug report and fix received pseudonymously.

  o Minor bugfixes (on 0.2.3.x):
    - Fix two cases in src/or/transports.c where we were calling
      fmt_addr() twice in a parameter list. Bug found by David
      Fifield. Fixes bug 7014; bugfix on 0.2.3.9-alpha.
    - Convert an assert in the pathbias code to a log message. The assert
      appears to only be triggerable by Tor2Web mode. Fixes bug 6866;
      bugfix on 0.2.3.17-beta.
    - Fix memory leaks whenever we logged any message about the "path
      bias" detection. Fixes bug 7022; bugfix on 0.2.3.21-rc.

  o Minor bugfixes (on 0.2.2.x and earlier):
    - Don't serve or accept v2 hidden service descriptors over a relay's
      DirPort. It's never correct to do so, and disabling it might
      make it more annoying to exploit any bugs that turn up in the
      descriptor-parsing code. Fixes bug 7149.
    - When relays refuse a "create" cell because their queue of pending
      create cells is too big (typically because their cpu can't keep up
      with the arrival rate), send back reason "resource limit" rather
      than reason "internal", so network measurement scripts can get a
      more accurate picture. Bugfix on 0.1.1.11-alpha; fixes bug 7037.
    - Correct file sizes when reading binary files on Cygwin, to avoid
      a bug where Tor would fail to read its state file. Fixes bug 6844;
      bugfix on 0.1.2.7-alpha.
    - Avoid undefined behavior when parsing the list of supported
      rendezvous/introduction protocols in a hidden service descriptor.
      Previously, Tor would have confused (as-yet-unused) protocol version
      numbers greater than 32 with lower ones on many platforms. Fixes
      bug 6827; bugfix on 0.2.0.10-alpha. Found by George Kadianakis.

  o Documentation fixes:
    - Clarify that hidden services are TCP only. Fixes bug 6024.


Changes in version 0.2.4.3-alpha - 2012-09-22
  Tor 0.2.4.3-alpha fixes another opportunity for a remotely triggerable
  assertion, resumes letting relays test reachability of their DirPort,
  and cleans up a bunch of smaller bugs.

  o Security fixes:
    - Fix an assertion failure in tor_timegm() that could be triggered
      by a badly formatted directory object. Bug found by fuzzing with
      Radamsa. Fixes bug 6811; bugfix on 0.2.0.20-rc.

  o Major bugfixes:
    - Fix a possible crash bug when checking for deactivated circuits
      in connection_or_flush_from_first_active_circuit(). Fixes bug 6341;
      bugfix on 0.2.2.7-alpha. Bug report and fix received pseudonymously.
    - Allow routers to detect that their own DirPorts are running. When
      we removed support for versions_supports_begindir, we also
      accidentally removed the mechanism we used to self-test our
      DirPort. Diagnosed with help from kargig. Fixes bugs 6814 and 6815;
      bugfix on 0.2.4.2-alpha.

  o Security features:
    - Switch to a completely time-invariant approach for picking nodes
      weighted by bandwidth. Our old approach would run through the
      part of the loop after it had made its choice slightly slower
      than it ran through the part of the loop before it had made its
      choice. Addresses ticket 6538.
    - Disable the use of Guard nodes when in Tor2WebMode. Guard usage
      by tor2web clients allows hidden services to identify tor2web
      clients through their repeated selection of the same rendezvous
      and introduction point circuit endpoints (their guards). Resolves
      ticket 6888.

  o Minor features:
    - Enable Tor to read configuration, state, and key information from
      a FIFO. Previously Tor would only read from files with a positive
      stat.st_size. Code from meejah; fixes bug 6044.

  o Minor bugfixes:
    - Correct file sizes when reading binary files on Cygwin, to avoid
      a bug where Tor would fail to read its state file. Fixes bug 6844;
      bugfix on 0.1.2.7-alpha.
    - Correctly handle votes with more than 31 flags. Fixes bug 6853;
      bugfix on 0.2.0.3-alpha.
    - When complaining about a client port on a public address, log
      which address we're complaining about. Fixes bug 4020; bugfix on
      0.2.3.3-alpha. Patch by Tom Fitzhenry.
    - Convert an assert in the pathbias code to a log message. The assert
      appears to only be triggerable by Tor2Web mode. Fixes bug 6866;
      bugfix on 0.2.3.17-beta.
    - Our new buildsystem was overzealous about rebuilding manpages: it
      would rebuild them all whenever any one of them changed. Now our
      dependency checking should be correct. Fixes bug 6843; bugfix on
      0.2.4.1-alpha.
    - Don't do reachability testing over IPv6 unless AuthDirPublishIPv6
      is set. Fixes bug 6880. Bugfix on 0.2.4.1-alpha.
    - Correct log printout about which address family is preferred
      when connecting to a bridge with both an IPv4 and IPv6 OR port.
      Fixes bug 6884; bugfix on 0.2.4.1-alpha.

  o Minor bugfixes (code cleanliness):
    - Fix round_to_power_of_2() so it doesn't invoke undefined behavior
      with large values. This situation was untriggered, but nevertheless
      incorrect. Fixes bug 6831; bugfix on 0.2.0.1-alpha.
    - Reject consensus votes with more than 64 known-flags. We aren't even
      close to that limit yet, and our code doesn't handle it correctly.
      Fixes bug 6833; bugfix on 0.2.0.1-alpha.
    - Avoid undefined behavior when parsing the list of supported
      rendezvous/introduction protocols in a hidden service descriptor.
      Previously, Tor would have confused (as-yet-unused) protocol version
      numbers greater than 32 with lower ones on many platforms. Fixes
      bug 6827; bugfix on 0.2.0.10-alpha. Found by George Kadianakis.
    - Fix handling of rendezvous client authorization types over 8.
      Fixes bug 6861; bugfix on 0.2.1.5-alpha.
    - Fix building with older versions of GCC (2.95, for one) that don't
      like preprocessor directives inside macro arguments. Found by
      grarpamp. Fixes bug 6842; bugfix on 0.2.4.2-alpha.
    - Switch weighted node selection rule from using a list of doubles
      to using a list of int64_t. This change should make the process
      slightly easier to debug and maintain. Needed to finish ticket 6538.

  o Code simplification and refactoring:
    - Move the generic "config" code into a new file, and have "config.c"
      hold only torrc- and state-related code. Resolves ticket 6823.
    - Move the core of our "choose a weighted element at random" logic
      into its own function, and give it unit tests. Now the logic is
      testable, and a little less fragile too.
    - Removed the testing_since field of node_t, which hasn't been used
      for anything since 0.2.0.9-alpha.

  o Documentation fixes:
    - Clarify that hidden services are TCP only. Fixes bug 6024.
    - Resolve a typo in torrc.sample.in. Fixes bug 6819; bugfix on
      0.2.3.14-alpha.


Changes in version 0.2.3.22-rc - 2012-09-11
  Tor 0.2.3.22-rc fixes another opportunity for a remotely triggerable
  assertion.

  o Security fixes:
    - Fix an assertion failure in tor_timegm() that could be triggered
      by a badly formatted directory object. Bug found by fuzzing with
      Radamsa. Fixes bug 6811; bugfix on 0.2.0.20-rc.

  o Minor bugfixes:
    - Avoid segfault when starting up having run with an extremely old
      version of Tor and parsing its state file. Fixes bug 6801; bugfix
      on 0.2.2.23-alpha.


Changes in version 0.2.2.39 - 2012-09-11
  Tor 0.2.2.39 fixes two more opportunities for remotely triggerable
  assertions.

  o Security fixes:
    - Fix an assertion failure in tor_timegm() that could be triggered
      by a badly formatted directory object. Bug found by fuzzing with
      Radamsa. Fixes bug 6811; bugfix on 0.2.0.20-rc.
    - Do not crash when comparing an address with port value 0 to an
      address policy. This bug could have been used to cause a remote
      assertion failure by or against directory authorities, or to
      allow some applications to crash clients. Fixes bug 6690; bugfix
      on 0.2.1.10-alpha.


Changes in version 0.2.4.2-alpha - 2012-09-10
  Tor 0.2.4.2-alpha enables port forwarding for pluggable transports,
  raises the default rate limiting even more, and makes the bootstrapping
  log messages less noisy.

  o Major features:
    - Automatically forward the TCP ports of pluggable transport
      proxies using tor-fw-helper if PortForwarding is enabled. Implements
      ticket 4567.

  o Major bugfixes:
    - Raise the default BandwidthRate/BandwidthBurst values from 5MB/10MB
      to 1GB/1GB. The previous defaults were intended to be "basically
      infinite", but it turns out they're now limiting our 100mbit+
      relays and bridges. Fixes bug 6605; bugfix on 0.2.0.10-alpha (the
      last time we raised it).

  o Minor features:
    - Detect when we're running with a version of OpenSSL other than the
      one we compiled with. This has occasionally given people hard-to-
      track-down errors.
    - Log fewer lines at level "notice" about our OpenSSL and Libevent
      versions and capabilities when everything is going right. Resolves
      part of ticket 6736.
    - Directory authorities no long accept descriptors for any version of
      Tor before 0.2.2.35, or for any 0.2.3 release before 0.2.3.10-alpha.
      These versions are insecure, unsupported, or both. Implements
      ticket 6789.

  o Minor bugfixes:
    - Rename the (internal-use-only) UsingTestingNetworkDefaults option
      to start with a triple-underscore so the controller won't touch it.
      Patch by Meejah. Fixes bug 3155. Bugfix on 0.2.2.23-alpha.
    - Avoid segfault when starting up having run with an extremely old
      version of Tor and parsing its state file. Fixes bug 6801; bugfix
      on 0.2.2.23-alpha.
    - Rename the (testing-use-only) _UseFilteringSSLBufferevents option
      so it doesn't start with _. Fixes bug 3155. Bugfix on 0.2.3.1-alpha.
    - Don't follow the NULL pointer if microdescriptor generation fails.
      (This does not appear to be triggerable, but it's best to be safe.)
      Found by "f. tp.". Fixes bug 6797; bugfix on 0.2.4.1-alpha.
    - Fix mis-declared dependencies on src/common/crypto.c and
      src/or/tor_main.c that could break out-of-tree builds under some
      circumstances. Fixes bug 6778; bugfix on 0.2.4.1-alpha.
    - Avoid a warning when building common_sha1.i out of tree. Fixes bug
      6778; bugfix on 0.2.4.1-alpha.
    - Fix a harmless (in this case) build warning for implicitly
      converting a strlen() to an int. Bugfix on 0.2.4.1-alpha.

  o Removed features:
    - Now that all versions before 0.2.2.x are disallowed, we no longer
      need to work around their missing features. Thus we can remove a
      bunch of compatibility code.

  o Code refactoring:
    - Tweak tor-fw-helper to accept an arbitrary amount of arbitrary
      TCP ports to forward. In the past it only accepted two ports:
      the ORPort and the DirPort.


Changes in version 0.2.4.1-alpha - 2012-09-05
  Tor 0.2.4.1-alpha lets bridges publish their pluggable transports to
  bridgedb; lets relays use IPv6 addresses and directory authorities
  advertise them; and switches to a cleaner build interface.

  This is the first alpha release in a new series, so expect there to
  be bugs. Users who would rather test out a more stable branch should
  stay with 0.2.3.x for now.

  o Major features (bridges):
    - Bridges now report the pluggable transports they support to the
      bridge authority, so it can pass the supported transports on to
      bridgedb and/or eventually do reachability testing. Implements
      ticket 3589.

  o Major features (IPv6):
    - Bridge authorities now accept IPv6 bridge addresses and include
      them in network status documents. Implements ticket 5534.
    - Clients who set "ClientUseIPv6 1" may connect to entry nodes over
      IPv6. Set "ClientPreferIPv6ORPort 1" to make this even more likely
      to happen. Implements ticket 5535.
    - All kind of relays, not just bridges, can now advertise an IPv6
      OR port. Implements ticket 6362.
    - Directory authorities vote on IPv6 OR ports using the new consensus
      method 14. Implements ticket 6363.

  o Major features (build):
    - Switch to a nonrecursive Makefile structure. Now instead of each
      Makefile.am invoking other Makefile.am's, there is a master
      Makefile.am that includes the others. This change makes our build
      process slightly more maintainable, and improves parallelism for
      building with make -j. Original patch by Stewart Smith; various
      fixes by Jim Meyering.
    - Where available, we now use automake's "silent" make rules by
      default, so that warnings are easier to spot. You can get the old
      behavior with "make V=1". Patch by Stewart Smith for ticket 6522.

  o Minor features (code security and spec conformance):
    - Clear keys and key-derived material left on the stack in
      rendservice.c and rendclient.c. Check return value of
      crypto_pk_write_private_key_to_string() in rend_service_load_keys().
      These fixes should make us more forward-secure against cold-boot
      attacks and the like. Fixes bug 2385.
    - Reject EXTEND cells sent to nonexistent streams. According to the
      spec, an EXTEND cell sent to _any_ nonzero stream ID is invalid, but
      we were only checking for stream IDs that were currently in use.
      Found while hunting for more instances of bug 6271. Bugfix on
      0.0.2pre8, which introduced incremental circuit construction.

  o Minor features (streamlining);
    - No longer include the "opt" prefix when generating routerinfos
      or v2 directories: it has been needless since Tor 0.1.2. Closes
      ticket 5124.
    - Remove some now-needless code that tried to aggressively flush
      OR connections as data was added to them. Since 0.2.0.1-alpha, our
      cell queue logic has saved us from the failure mode that this code
      was supposed to prevent. Removing this code will limit the number
      of baroque control flow paths through Tor's network logic. Reported
      pseudonymously on IRC. Fixes bug 6468; bugfix on 0.2.0.1-alpha.

  o Minor features (controller):
    - Add a "GETINFO signal/names" control port command. Implements
      ticket 3842.
    - Provide default values for all options via "GETINFO config/defaults".
      Implements ticket 4971.

  o Minor features (IPv6):
    - New config option "AuthDirHasIPv6Connectivity 1" that directory
      authorities should set if they have IPv6 connectivity and want to
      do reachability tests for IPv6 relays. Implements feature 5974.
    - A relay with an IPv6 OR port now sends that address in NETINFO
      cells (in addition to its other address). Implements ticket 6364.

  o Minor features (log messages):
    - Omit the first heartbeat log message, because it never has anything
      useful to say, and it clutters up the bootstrapping messages.
      Resolves ticket 6758.
    - Don't log about reloading the microdescriptor cache at startup. Our
      bootstrap warnings are supposed to tell the user when there's a
      problem, and our bootstrap notices say when there isn't. Resolves
      ticket 6759; bugfix on 0.2.2.6-alpha.
    - Don't log "I learned some more directory information" when we're
      reading cached directory information. Reserve it for when new
      directory information arrives in response to a fetch. Resolves
      ticket 6760.
    - Prevent rounding error in path bias counts when scaling
      them down, and use the correct scale factor default. Also demote
      some path bias related log messages down a level and make others
      less scary sounding. Fixes bug 6647. Bugfix against 0.2.3.17-beta.
    - We no longer warn so much when generating manpages from their
      asciidoc source.

  o Code simplifications and refactoring:
    - Enhance our internal sscanf replacement so that we can eliminate
      the last remaining uses of the system sscanf. (Though those uses
      of sscanf were safe, sscanf itself is generally error prone, so
      we want to eliminate when we can.) Fixes ticket 4195 and Coverity
      CID 448.
    - Move ipv6_preferred from routerinfo_t to node_t. Addresses bug 4620.
    - Move last_reachable and testing_since from routerinfo_t to node_t.
      Implements ticket 5529.
    - Add replaycache_t structure, functions and unit tests, then refactor
      rend_service_introduce() to be more clear to read, improve, debug,
      and test. Resolves bug 6177.
    - Finally remove support for malloc_good_size and malloc_usable_size.
      We had hoped that these functions would let us eke a little more
      memory out of our malloc implementation. Unfortunately, the only
      implementations that provided these functions are also ones that
      are already efficient about not overallocation: they never got us
      more than 7 or so bytes per allocation. Removing them saves us a
      little code complexity and a nontrivial amount of build complexity.

  o New requirements:
    - Tor maintainers now require Automake version 1.9 or later to build
      Tor from the Git repository. (Automake is not required when building
      from a source distribution.)


Changes in version 0.2.3.21-rc - 2012-09-05
  Tor 0.2.3.21-rc is the fourth release candidate for the Tor 0.2.3.x
  series. It fixes a trio of potential security bugs, fixes a bug where
  we were leaving some of the fast relays out of the microdescriptor
  consensus, resumes interpreting "ORPort 0" and "DirPort 0" correctly,
  and cleans up other smaller issues.

  o Major bugfixes (security):
    - Tear down the circuit if we get an unexpected SENDME cell. Clients
      could use this trick to make their circuits receive cells faster
      than our flow control would have allowed, or to gum up the network,
      or possibly to do targeted memory denial-of-service attacks on
      entry nodes. Fixes bug 6252. Bugfix on the 54th commit on Tor --
      from July 2002, before the release of Tor 0.0.0. We had committed
      this patch previously, but we had to revert it because of bug 6271.
      Now that 6271 is fixed, this patch appears to work.
    - Reject any attempt to extend to an internal address. Without
      this fix, a router could be used to probe addresses on an internal
      network to see whether they were accepting connections. Fixes bug
      6710; bugfix on 0.0.8pre1.
    - Do not crash when comparing an address with port value 0 to an
      address policy. This bug could have been used to cause a remote
      assertion failure by or against directory authorities, or to
      allow some applications to crash clients. Fixes bug 6690; bugfix
      on 0.2.1.10-alpha.

  o Major bugfixes:
    - Remove the upper bound on microdescriptor length. We were hitting
      the limit for routers with complex exit policies or family
      declarations, causing clients to not use them. Fixes the first
      piece of bug 6404; fix on 0.2.2.6-alpha.
    - Detect "ORPort 0" as meaning, uniformly, that we're not running
      as a relay. Previously, some of our code would treat the presence
      of any ORPort line as meaning that we should act like a relay,
      even though our new listener code would correctly not open any
      ORPorts for ORPort 0. Similar bugs in other Port options are also
      fixed. Fixes the first half of bug 6507; bugfix on 0.2.3.3-alpha.

  o Minor bugfixes:
    - Avoid a pair of double-free and use-after-mark bugs that can
      occur with certain timings in canceled and re-received DNS
      requests. Fixes bug 6472; bugfix on 0.0.7rc1.
    - Fix build and 64-bit compile warnings from --enable-openbsd-malloc.
      Fixes bug 6379. Bugfix on 0.2.0.20-rc.
    - Allow one-hop directory fetching circuits the full "circuit build
      timeout" period, rather than just half of it, before failing them
      and marking the relay down. This fix should help reduce cases where
      clients declare relays (or worse, bridges) unreachable because
      the TLS handshake takes a few seconds to complete. Fixes bug 6743;
      bugfix on 0.2.2.2-alpha, where we changed the timeout from a static
      30 seconds.
    - Authorities no longer include any router in their microdescriptor
      consensuses for which they couldn't generate or agree on a
      microdescriptor. Fixes the second piece of bug 6404; fix on
      0.2.2.6-alpha.
    - Detect and reject attempts to specify both "FooPort" and
      "FooPort 0" in the same configuration domain. (It's still okay
      to have a FooPort in your configuration file, and use "FooPort 0"
      on the command line to disable it.) Fixes the second half of bug
      6507; bugfix on 0.2.3.3-alpha.
    - Make wildcarded addresses (that is, ones beginning with "*.") work
      when provided via the controller's MapAddress command. Previously,
      they were accepted, but we never actually noticed that they were
      wildcards. Fixes bug 6244; bugfix on 0.2.3.9-alpha.
    - Avoid crashing on a malformed state file where EntryGuardPathBias
      precedes EntryGuard. Fix for bug 6774; bugfix on 0.2.3.17-beta.
    - Add a (probably redundant) memory clear between iterations of
      the router status voting loop, to prevent future coding errors
      where data might leak between iterations of the loop. Resolves
      ticket 6514.

  o Minor bugfixes (log messages):
    - Downgrade "set buildtimeout to low value" messages to "info"
      severity; they were never an actual problem, there was never
      anything reasonable to do about them, and they tended to spam logs
      from time to time. Fixes bug 6251; bugfix on 0.2.2.2-alpha.
    - Downgrade path-bias warning messages to "info". We'll try to get
      them working better in 0.2.4. Add internal circuit construction
      state to protect against the noisy warn message "Unexpectedly high
      circuit_successes". Also add some additional rate-limited notice
      messages to help determine the root cause of the warn. Fixes bug
      6475. Bugfix against 0.2.3.17-beta.
    - Move log message when unable to find a microdesc in a routerstatus
      entry to parse time. Previously we'd spam this warning every time
      we tried to figure out which microdescriptors to download. Fixes
      the third piece of bug 6404; fix on 0.2.3.18-rc.

  o Minor features:
    - Consider new, removed or changed IPv6 OR ports a non-cosmetic
      change when the authority is deciding whether to accept a newly
      uploaded descriptor. Implements ticket 6423.
    - Add missing documentation for consensus and microdesc files.
      Resolves ticket 6732.


Changes in version 0.2.2.38 - 2012-08-12
  Tor 0.2.2.38 fixes a remotely triggerable crash bug, and fixes a timing
  attack that could in theory leak path information.

  o Security fixes:
    - Avoid an uninitialized memory read when reading a vote or consensus
      document that has an unrecognized flavor name. This read could
      lead to a remote crash bug. Fixes bug 6530; bugfix on 0.2.2.6-alpha.
    - Try to leak less information about what relays a client is
      choosing to a side-channel attacker. Previously, a Tor client would
      stop iterating through the list of available relays as soon as it
      had chosen one, thus finishing a little earlier when it picked
      a router earlier in the list. If an attacker can recover this
      timing information (nontrivial but not proven to be impossible),
      they could learn some coarse-grained information about which relays
      a client was picking (middle nodes in particular are likelier to
      be affected than exits). The timing attack might be mitigated by
      other factors (see bug 6537 for some discussion), but it's best
      not to take chances. Fixes bug 6537; bugfix on 0.0.8rc1.


Changes in version 0.2.3.20-rc - 2012-08-05
  Tor 0.2.3.20-rc is the third release candidate for the Tor 0.2.3.x
  series. It fixes a pair of code security bugs and a potential anonymity
  issue, updates our RPM spec files, and cleans up other smaller issues.

  o Security fixes:
    - Avoid read-from-freed-memory and double-free bugs that could occur
      when a DNS request fails while launching it. Fixes bug 6480;
      bugfix on 0.2.0.1-alpha.
    - Avoid an uninitialized memory read when reading a vote or consensus
      document that has an unrecognized flavor name. This read could
      lead to a remote crash bug. Fixes bug 6530; bugfix on 0.2.2.6-alpha.
    - Try to leak less information about what relays a client is
      choosing to a side-channel attacker. Previously, a Tor client would
      stop iterating through the list of available relays as soon as it
      had chosen one, thus finishing a little earlier when it picked
      a router earlier in the list. If an attacker can recover this
      timing information (nontrivial but not proven to be impossible),
      they could learn some coarse-grained information about which relays
      a client was picking (middle nodes in particular are likelier to
      be affected than exits). The timing attack might be mitigated by
      other factors (see bug 6537 for some discussion), but it's best
      not to take chances. Fixes bug 6537; bugfix on 0.0.8rc1.

  o Minor features:
    - Try to make the warning when giving an obsolete SOCKSListenAddress
      a little more useful.
    - Terminate active server managed proxies if Tor stops being a
      relay. Addresses parts of bug 6274; bugfix on 0.2.3.6-alpha.
    - Provide a better error message about possible OSX Asciidoc failure
      reasons. Fixes bug 6436.
    - Warn when Tor is configured to use accounting in a way that can
      link a hidden service to some other hidden service or public
      address. Resolves ticket 6490.

  o Minor bugfixes:
    - Check return value of fputs() when writing authority certificate
      file. Fixes Coverity issue 709056; bugfix on 0.2.0.1-alpha.
    - Ignore ServerTransportPlugin lines when Tor is not configured as
      a relay. Fixes bug 6274; bugfix on 0.2.3.6-alpha.
    - When disabling guards for having too high a proportion of failed
      circuits, make sure to look at each guard. Fixes bug 6397; bugfix
      on 0.2.3.17-beta.

  o Packaging (RPM):
    - Update our default RPM spec files to work with mock and rpmbuild
      on RHEL/Fedora. They have an updated set of dependencies and
      conflicts, a fix for an ancient typo when creating the "_tor"
      user, and better instructions. Thanks to Ondrej Mikle for the
      patch series. Fixes bug 6043.

  o Testing:
    - Make it possible to set the TestingTorNetwork configuration
      option using AlternateDirAuthority and AlternateBridgeAuthority
      as an alternative to setting DirServer. Addresses ticket 6377.

  o Documentation:
    - Clarify the documentation for the Alternate*Authority options.
      Fixes bug 6387.
    - Fix some typos in the manpages. Patch from A. Costa. Fixes bug 6500.

  o Code simplification and refactoring:
    - Do not use SMARTLIST_FOREACH for any loop whose body exceeds
      10 lines. Also, don't nest them. Doing so in the past has
      led to hard-to-debug code. The new style is to use the
      SMARTLIST_FOREACH_{BEGIN,END} pair. Addresses issue 6400.


Changes in version 0.2.3.19-rc - 2012-07-06
  Tor 0.2.3.19-rc is the second release candidate for the Tor 0.2.3.x
  series. It fixes the compile on Windows, reverts to a GeoIP database
  that isn't as broken, and fixes a flow control bug that has been around
  since the beginning of Tor.

  o Major bugfixes:
    - Fix a bug handling SENDME cells on nonexistent streams that could
      result in bizarre window values. Report and patch contributed
      pseudonymously. Fixes part of bug 6271. This bug was introduced
      before the first Tor release, in svn commit r152.
    - Revert to the May 1 2012 Maxmind GeoLite Country database. In the
      June 2012 database, Maxmind marked many Tor relays as country "A1",
      which will cause risky behavior for clients that set EntryNodes
      or ExitNodes. Addresses bug 6334; bugfix on 0.2.3.17-beta.
    - Instead of ENOBUFS on Windows, say WSAENOBUFS. Fixes compilation
      on Windows. Fixes bug 6296; bugfix on 0.2.3.18-rc.

  o Minor bugfixes:
    - Fix wrong TCP port range in parse_port_range(). Fixes bug 6218;
      bugfix on 0.2.1.10-alpha.


Changes in version 0.2.3.18-rc - 2012-06-28
  Tor 0.2.3.18-rc is the first release candidate for the Tor 0.2.3.x
  series. It fixes a few smaller bugs, but generally appears stable.
  Please test it and let us know whether it is!

  o Major bugfixes:
    - Allow wildcarded mapaddress targets to be specified on the
      controlport. Partially fixes bug 6244; bugfix on 0.2.3.9-alpha.
    - Make our linker option detection code more robust against linkers
      such as on FreeBSD 8, where a bad combination of options completes
      successfully but makes an unrunnable binary. Fixes bug 6173;
      bugfix on 0.2.3.17-beta.

  o Minor bugfixes (on 0.2.2.x and earlier):
    - Avoid a false positive in the util/threads unit test by increasing
      the maximum timeout time. Fixes bug 6227; bugfix on 0.2.0.4-alpha.
    - Replace "Sending publish request" log messages with "Launching
      upload", so that they no longer confusingly imply that we're
      sending something to a directory we might not even be connected
      to yet. Fixes bug 3311; bugfix on 0.2.0.10-alpha.
    - Make sure to set *socket_error in all error cases in
      connection_connect(), so it can't produce a warning about
      errno being zero from errno_to_orconn_end_reason(). Bugfix on
      0.2.1.1-alpha; resolves ticket 6028.
    - Downgrade "Got a certificate, but we already have it" log messages
      from warning to info, except when we're a dirauth. Fixes bug 5238;
      bugfix on 0.2.1.7-alpha.
    - When checking for requested signatures on the latest consensus
      before serving it to a client, make sure to check the right
      consensus flavor. Bugfix on 0.2.2.6-alpha.
    - Downgrade "eventdns rejected address" message to LOG_PROTOCOL_WARN.
      Fixes bug 5932; bugfix on 0.2.2.7-alpha.

  o Minor bugfixes (on 0.2.3.x):
    - Make format_helper_exit_status() avoid unnecessary space padding
      and stop confusing log_from_pipe(). Fixes ticket 5557; bugfix
      on 0.2.3.1-alpha.
    - Downgrade a message about cleaning the microdescriptor cache to
      "info" from "notice". Fixes bug 6238; bugfix on 0.2.3.1-alpha.
    - Log a BUG message at severity INFO if we have a networkstatus with
      a missing entry for some microdescriptor. Continues on a patch
      to 0.2.3.2-alpha.
    - Improve the log message when a managed proxy fails to launch. Fixes
      bug 5099; bugfix on 0.2.3.6-alpha.
    - Don't do DNS lookups when parsing corrupted managed proxy protocol
      messages. Fixes bug 6226; bugfix on 0.2.3.6-alpha.
    - When formatting wildcarded address mappings for the controller,
      be sure to include "*." as appropriate. Partially fixes bug 6244;
      bugfix on 0.2.3.9-alpha.
    - Avoid a warning caused by using strcspn() from glibc with clang 3.0.
      Bugfix on 0.2.3.13-alpha.
    - Stop logging messages about running with circuit timeout learning
      enabled at severity LD_BUG. Fixes bug 6169; bugfix on 0.2.3.17-beta.
    - Disable a spurious warning about reading on a marked and flushing
      connection. We shouldn't be doing that, but apparently we
      sometimes do. Fixes bug 6203; bugfix on 0.2.3.17-beta.
    - Fix a bug that stopped AllowDotExit from working on addresses
      that had an entry in the DNS cache. Fixes bug 6211; bugfix on
      0.2.3.17-beta.

  o Code simplification, refactoring, unit tests:
    - Move tor_gettimeofday_cached() into compat_libevent.c, and use
      Libevent's notion of cached time when possible.
    - Remove duplicate code for invoking getrlimit() from control.c.
    - Add a unit test for the environment_variable_names_equal function.

  o Documentation:
    - Document the --defaults-torrc option, and the new (in 0.2.3)
      semantics for overriding, extending, and clearing lists of
      options. Closes bug 4748.


Changes in version 0.2.3.17-beta - 2012-06-15
  Tor 0.2.3.17-beta enables compiler and linker hardening by default,
  gets our TLS handshake back on track for being able to blend in with
  Firefox, fixes a big bug in 0.2.3.16-alpha that broke Tor's interaction
  with Vidalia, and otherwise continues to get us closer to a release
  candidate.

  o Major features:
    - Enable gcc and ld hardening by default. Resolves ticket 5210.
    - Update TLS cipher list to match Firefox 8 and later. Resolves
      ticket 4744.
    - Implement the client side of proposal 198: remove support for
      clients falsely claiming to support standard ciphersuites that
      they can actually provide. As of modern OpenSSL versions, it's not
      necessary to fake any standard ciphersuite, and doing so prevents
      us from using better ciphersuites in the future, since servers
      can't know whether an advertised ciphersuite is really supported or
      not. Some hosts -- notably, ones with very old versions of OpenSSL
      or where OpenSSL has been built with ECC disabled -- will stand
      out because of this change; TBB users should not be affected.

  o Major bugfixes:
    - Change the default value for DynamicDHGroups (introduced in
      0.2.3.9-alpha) to 0. This feature can make Tor relays less
      identifiable by their use of the mod_ssl DH group, but at
      the cost of some usability (#4721) and bridge tracing (#6087)
      regressions. Resolves ticket 5598.
    - Send a CRLF at the end of each STATUS_* control protocol event. This
      bug tickled a bug in Vidalia which would make it freeze. Fixes
      bug 6094; bugfix on 0.2.3.16-alpha.

  o Minor bugfixes:
    - Disable writing on marked-for-close connections when they are
      blocked on bandwidth, to prevent busy-looping in Libevent. Fixes
      bug 5263; bugfix on 0.0.2pre13, where we first added a special
      case for flushing marked connections.
    - Detect SSL handshake even when the initial attempt to write the
      server hello fails. Fixes bug 4592; bugfix on 0.2.0.13-alpha.
    - Change the AllowDotExit rules so they should actually work.
      We now enforce AllowDotExit only immediately after receiving an
      address via SOCKS or DNSPort: other sources are free to provide
      .exit addresses after the resolution occurs. Fixes bug 3940;
      bugfix on 0.2.2.1-alpha.
    - Fix a (harmless) integer overflow in cell statistics reported by
      some fast relays. Fixes bug 5849; bugfix on 0.2.2.1-alpha.
    - Make sure circuitbuild.c checks LearnCircuitBuildTimeout in all the
      right places and never depends on the consensus parameters or
      computes adaptive timeouts when it is disabled. Fixes bug 5049;
      bugfix on 0.2.2.14-alpha.
    - When building Tor on Windows with -DUNICODE (not default), ensure
      that error messages, filenames, and DNS server names are always
      NUL-terminated when we convert them to a single-byte encoding.
      Fixes bug 5909; bugfix on 0.2.2.16-alpha.
    - Make Tor build correctly again with -DUNICODE -D_UNICODE defined.
      Fixes bug 6097; bugfix on 0.2.2.16-alpha.
    - Fix an edge case where TestingTorNetwork is set but the authorities
      and relays all have an uptime of zero, where the private Tor network
      could briefly lack support for hidden services. Fixes bug 3886;
      bugfix on 0.2.2.18-alpha.
    - Correct the manpage's descriptions for the default values of
      DirReqStatistics and ExtraInfoStatistics. Fixes bug 2865; bugfix
      on 0.2.3.1-alpha.
    - Fix the documentation for the --hush and --quiet command line
      options, which changed their behavior back in 0.2.3.3-alpha.
    - Fix compilation warning with clang 3.1. Fixes bug 6141; bugfix on
      0.2.3.11-alpha.

  o Minor features:
    - Rate-limit the "Weighted bandwidth is 0.000000" message, and add
      more information to it, so that we can track it down in case it
      returns again. Mitigates bug 5235.
    - Check CircuitBuildTimeout and LearnCircuitBuildTimeout in
      options_validate(); warn if LearnCircuitBuildTimeout is disabled and
      CircuitBuildTimeout is set unreasonably low. Resolves ticket 5452.
    - Warn the user when HTTPProxy, but no other proxy type, is
      configured. This can cause surprising behavior: it doesn't send
      all of Tor's traffic over the HTTPProxy -- it sends unencrypted
      directory traffic only. Resolves ticket 4663.
    - Issue a notice if a guard completes less than 40% of your circuits.
      Threshold is configurable by torrc option PathBiasNoticeRate and
      consensus parameter pb_noticepct. There is additional, off-by-
      default code to disable guards which fail too many circuits.
      Addresses ticket 5458.
    - Update to the June 6 2012 Maxmind GeoLite Country database.

  o Code simplifications and refactoring:
    - Remove validate_pluggable_transports_config(): its warning
      message is now handled by connection_or_connect().


Changes in version 0.2.2.37 - 2012-06-06
  Tor 0.2.2.37 introduces a workaround for a critical renegotiation
  bug in OpenSSL 1.0.1 (where 20% of the Tor network can't talk to itself
  currently).

  o Major bugfixes:
    - Work around a bug in OpenSSL that broke renegotiation with TLS
      1.1 and TLS 1.2. Without this workaround, all attempts to speak
      the v2 Tor connection protocol when both sides were using OpenSSL
      1.0.1 would fail. Resolves ticket 6033.
    - When waiting for a client to renegotiate, don't allow it to add
      any bytes to the input buffer. This fixes a potential DoS issue.
      Fixes bugs 5934 and 6007; bugfix on 0.2.0.20-rc.
    - Fix an edge case where if we fetch or publish a hidden service
      descriptor, we might build a 4-hop circuit and then use that circuit
      for exiting afterwards -- even if the new last hop doesn't obey our
      ExitNodes config option. Fixes bug 5283; bugfix on 0.2.0.10-alpha.

  o Minor bugfixes:
    - Fix a build warning with Clang 3.1 related to our use of vasprintf.
      Fixes bug 5969. Bugfix on 0.2.2.11-alpha.

  o Minor features:
    - Tell GCC and Clang to check for any errors in format strings passed
      to the tor_v*(print|scan)f functions.


Changes in version 0.2.3.16-alpha - 2012-06-05
  Tor 0.2.3.16-alpha introduces a workaround for a critical renegotiation
  bug in OpenSSL 1.0.1 (where 20% of the Tor network can't talk to itself
  currently). It also fixes a variety of smaller bugs and other cleanups
  that get us closer to a release candidate.

  o Major bugfixes (general):
    - Work around a bug in OpenSSL that broke renegotiation with TLS
      1.1 and TLS 1.2. Without this workaround, all attempts to speak
      the v2 Tor connection protocol when both sides were using OpenSSL
      1.0.1 would fail. Resolves ticket 6033.
    - When waiting for a client to renegotiate, don't allow it to add
      any bytes to the input buffer. This fixes a potential DoS issue.
      Fixes bugs 5934 and 6007; bugfix on 0.2.0.20-rc.
    - Pass correct OR address to managed proxies (like obfsproxy),
      even when ORListenAddress is used. Fixes bug 4865; bugfix on
      0.2.3.9-alpha.
    - The advertised platform of a router now includes only its operating
      system's name (e.g., "Linux", "Darwin", "Windows 7"), and not its
      service pack level (for Windows) or its CPU architecture (for Unix).
      We also no longer include the "git-XYZ" tag in the version. Resolves
      part of bug 2988.

  o Major bugfixes (clients):
    - If we are unable to find any exit that supports our predicted ports,
      stop calling them predicted, so that we don't loop and build
      hopeless circuits indefinitely. Fixes bug 3296; bugfix on 0.0.9pre6,
      which introduced predicted ports.
    - Fix an edge case where if we fetch or publish a hidden service
      descriptor, we might build a 4-hop circuit and then use that circuit
      for exiting afterwards -- even if the new last hop doesn't obey our
      ExitNodes config option. Fixes bug 5283; bugfix on 0.2.0.10-alpha.
    - Check at each new consensus whether our entry guards were picked
      long enough ago that we should rotate them. Previously, we only
      did this check at startup, which could lead to us holding a guard
      indefinitely. Fixes bug 5380; bugfix on 0.2.1.14-rc.
    - When fetching a bridge descriptor from a bridge authority,
      always do so anonymously, whether we have been able to open
      circuits or not. Partial fix for bug 1938; bugfix on 0.2.0.7-alpha.
      This behavior makes it *safer* to use UpdateBridgesFromAuthority,
      but we'll need to wait for bug 6010 before it's actually usable.

  o Major bugfixes (directory authorities):
    - When computing weight parameters, behave more robustly in the
      presence of a bad bwweightscale value. Previously, the authorities
      would crash if they agreed on a sufficiently broken weight_scale
      value: now, they use a reasonable default and carry on. Partial
      fix for 5786; bugfix on 0.2.2.17-alpha.
    - Check more thoroughly to prevent a rogue authority from
      double-voting on any consensus directory parameter. Previously,
      authorities would crash in this case if the total number of
      votes for any parameter exceeded the number of active voters,
      but would let it pass otherwise. Partial fix for bug 5786; bugfix
      on 0.2.2.2-alpha.

  o Minor features:
    - Rate-limit log messages when asked to connect anonymously to
      a private address. When these hit, they tended to hit fast and
      often. Also, don't bother trying to connect to addresses that we
      are sure will resolve to 127.0.0.1: getting 127.0.0.1 in a directory
      reply makes us think we have been lied to, even when the address the
      client tried to connect to was "localhost." Resolves ticket 2822.
    - Allow packagers to insert an extra string in server descriptor
      platform lines by setting the preprocessor variable TOR_BUILD_TAG.
      Resolves the rest of ticket 2988.
    - Raise the threshold of server descriptors needed (75%) and exit
      server descriptors needed (50%) before we will declare ourselves
      bootstrapped. This will make clients start building circuits a
      little later, but makes the initially constructed circuits less
      skewed and less in conflict with further directory fetches. Fixes
      ticket 3196.
    - Close any connection that sends unrecognized junk before the
      handshake. Solves an issue noted in bug 4369.
    - Improve log messages about managed transports. Resolves ticket 5070.
    - Tag a bridge's descriptor as "never to be sent unencrypted".
      This shouldn't matter, since bridges don't open non-anonymous
      connections to the bridge authority and don't allow unencrypted
      directory connections from clients, but we might as well make
      sure. Closes bug 5139.
    - Expose our view of whether we have gone dormant to the controller,
      via a new "GETINFO dormant" value. Torbutton and other controllers
      can use this to avoid doing periodic requests through Tor while
      it's dormant (bug 4718). Fixes bug 5954.
    - Tell GCC and Clang to check for any errors in format strings passed
      to the tor_v*(print|scan)f functions.
    - Update to the May 1 2012 Maxmind GeoLite Country database.

  o Minor bugfixes (already included in 0.2.2.36):
    - Reject out-of-range times like 23:59:61 in parse_rfc1123_time().
      Fixes bug 5346; bugfix on 0.0.8pre3.
    - Correct parsing of certain date types in parse_http_time().
      Without this patch, If-Modified-Since would behave
      incorrectly. Fixes bug 5346; bugfix on 0.2.0.2-alpha. Patch from
      Esteban Manchado Velázques.
    - Make our number-parsing functions always treat too-large values
      as an error, even when those values exceed the width of the
      underlying type. Previously, if the caller provided these
      functions with minima or maxima set to the extreme values of the
      underlying integer type, these functions would return those
      values on overflow rather than treating overflow as an error.
      Fixes part of bug 5786; bugfix on 0.0.9.
    - If we hit the error case where routerlist_insert() replaces an
      existing (old) server descriptor, make sure to remove that
      server descriptor from the old_routers list. Fix related to bug
      1776. Bugfix on 0.2.2.18-alpha.
    - Clarify the behavior of MaxCircuitDirtiness with hidden service
      circuits. Fixes issue 5259.

  o Minor bugfixes (coding cleanup, on 0.2.2.x and earlier):
    - Prevent a null-pointer dereference when receiving a data cell
      for a nonexistent stream when the circuit in question has an
      empty deliver window. We don't believe this is triggerable,
      since we don't currently allow deliver windows to become empty,
      but the logic is tricky enough that it's better to make the code
      robust. Fixes bug 5541; bugfix on 0.0.2pre14.
    - Fix a memory leak when trying to launch a DNS request when the
      network is disabled or the nameservers are unconfigurable. Fixes
      bug 5916; bugfix on Tor 0.1.2.1-alpha (for the unconfigurable
      nameserver case) and on 0.2.3.9-alpha (for the DisableNetwork case).
    - Don't hold a Windows file handle open for every file mapping;
      the file mapping handle is sufficient. Fixes bug 5951; bugfix on
      0.1.2.1-alpha.
    - Avoid O(n^2) performance characteristics when parsing a large
      extrainfo cache. Fixes bug 5828; bugfix on 0.2.0.1-alpha.
    - Format more doubles with %f, not %lf. Patch from grarpamp to make
      Tor build correctly on older BSDs again. Fixes bug 3894; bugfix on
      Tor 0.2.0.8-alpha.
    - Make our replacement implementation of strtok_r() compatible with
      the standard behavior of strtok_r(). Patch by nils. Fixes bug 5091;
      bugfix on 0.2.2.1-alpha.
    - Fix a NULL-pointer dereference on a badly formed
      SETCIRCUITPURPOSE command. Found by mikeyc. Fixes bug 5796;
      bugfix on 0.2.2.9-alpha.
    - Fix a build warning with Clang 3.1 related to our use of vasprintf.
      Fixes bug 5969. Bugfix on 0.2.2.11-alpha.
    - Defensively refactor rend_mid_rendezvous() so that protocol
      violations and length checks happen in the beginning. Fixes
      bug 5645.
    - Set _WIN32_WINNT to 0x0501 consistently throughout the code, so
      that IPv6 stuff will compile on MSVC, and compilation issues
      will be easier to track down. Fixes bug 5861.

  o Minor bugfixes (correctness, on 0.2.2.x and earlier):
    - Exit nodes now correctly report EADDRINUSE and EADDRNOTAVAIL as
      resource exhaustion, so that clients can adjust their load to
      try other exits. Fixes bug 4710; bugfix on 0.1.0.1-rc, which
      started using END_STREAM_REASON_RESOURCELIMIT.
    - Don't check for whether the address we're using for outbound
      connections has changed until after the outbound connection has
      completed. On Windows, getsockname() doesn't succeed until the
      connection is finished. Fixes bug 5374; bugfix on 0.1.1.14-alpha.
    - If the configuration tries to set MyFamily on a bridge, refuse to
      do so, and warn about the security implications. Fixes bug 4657;
      bugfix on 0.2.0.3-alpha.
    - If the client fails to set a reasonable set of ciphersuites
      during its v2 handshake renegotiation, allow the renegotiation to
      continue nevertheless (i.e. send all the required certificates).
      Fixes bug 4591; bugfix on 0.2.0.20-rc.
    - When we receive a SIGHUP and the controller __ReloadTorrcOnSIGHUP
      option is set to 0 (which Vidalia version 0.2.16 now does when
      a SAVECONF attempt fails), perform other actions that SIGHUP
      usually causes (like reopening the logs). Fixes bug 5095; bugfix
      on 0.2.1.9-alpha.
    - If we fail to write a microdescriptor to the disk cache, do not
      continue replacing the old microdescriptor file. Fixes bug 2954;
      bugfix on 0.2.2.6-alpha.
    - Exit nodes don't need to fetch certificates for authorities that
      they don't recognize; only directory authorities, bridges,
      and caches need to do that. Fixes part of bug 2297; bugfix on
      0.2.2.11-alpha.
    - Correctly handle checking the permissions on the parent
      directory of a control socket in the root directory. Bug found
      by Esteban Manchado Velázquez. Fixes bug 5089; bugfix on Tor
      0.2.2.26-beta.
    - When told to add a bridge with the same digest as a preexisting
      bridge but a different addr:port, change the addr:port as
      requested. Previously we would not notice the change. Fixes half
      of bug 5603; fix on 0.2.2.26-beta.
    - End AUTHCHALLENGE error messages (in the control protocol) with
      a CRLF. Fixes bug 5760; bugfix on 0.2.2.36 and 0.2.3.13-alpha.

  o Minor bugfixes (on 0.2.3.x):
    - Turn an assertion (that the number of handshakes received as a
      server is not < 1) into a warning. Fixes bug 4873; bugfix on
      0.2.3.1-alpha.
    - Format IPv4 addresses correctly in ADDRMAP events. (Previously,
      we had reversed them when the answer was cached.) Fixes bug
      5723; bugfix on 0.2.3.1-alpha.
    - Work correctly on Linux systems with accept4 support advertised in
      their headers, but without accept4 support in the kernel. Fix
      by murb. Fixes bug 5762; bugfix on 0.2.3.1-alpha.
    - When told to add a bridge with the same addr:port as a preexisting
      bridge but a different transport, change the transport as
      requested. Previously we would not notice the change. Fixes half
      of bug 5603; fix on 0.2.3.2-alpha.
    - Avoid a "double-reply" warning when replying to a SOCKS request
      with a parse error. Patch from Fabian Keil. Fixes bug 4108;
      bugfix on 0.2.3.4-alpha.
    - Fix a bug where a bridge authority crashes if it has seen no
      directory requests when it's time to write statistics to disk.
      Fixes bug 5891; bugfix on 0.2.3.6-alpha. Also fixes bug 5508 in
      a better way.
    - Don't try to open non-control listeners when DisableNetwork is set.
      Previously, we'd open all listeners, then immediately close them.
      Fixes bug 5604; bugfix on 0.2.3.9-alpha.
    - Don't abort the managed proxy protocol if the managed proxy
      sends us an unrecognized line; ignore it instead. Fixes bug
      5910; bugfix on 0.2.3.9-alpha.
    - Fix a compile warning in crypto.c when compiling with clang 3.1.
      Fixes bug 5969, bugfix on 0.2.3.9-alpha.
    - Fix a compilation issue on GNU Hurd, which doesn't have PATH_MAX.
      Fixes bug 5355; bugfix on 0.2.3.11-alpha.
    - Remove bogus definition of "_WIN32" from src/win32/orconfig.h, to
      unbreak the MSVC build. Fixes bug 5858; bugfix on 0.2.3.12-alpha.
    - Resolve numerous small warnings and build issues with MSVC. Resolves
      bug 5859.

  o Documentation fixes:
    - Improve the manual's documentation for the NT Service command-line
      options. Addresses ticket 3964.
    - Clarify SessionGroup documentation slightly; resolves ticket 5437.
    - Document the changes to the ORPort and DirPort options, and the
      fact that {OR/Dir}ListenAddress is now unnecessary (and
      therefore deprecated). Resolves ticket 5597.

  o Removed files:
    - Remove the torrc.bridge file: we don't use it for anything, and
      it had become badly desynchronized from torrc.sample. Resolves
      bug 5622.


Changes in version 0.2.2.36 - 2012-05-24
  Tor 0.2.2.36 updates the addresses for two of the eight directory
  authorities, fixes some potential anonymity and security issues,
  and fixes several crash bugs.

  Tor 0.2.1.x has reached its end-of-life. Those Tor versions have many
  known flaws, and nobody should be using them. You should upgrade. If
  you're using a Linux or BSD and its packages are obsolete, stop using
  those packages and upgrade anyway.

  o Directory authority changes:
    - Change IP address for maatuska (v3 directory authority).
    - Change IP address for ides (v3 directory authority), and rename
      it to turtles.

  o Security fixes:
    - When building or running with any version of OpenSSL earlier
      than 0.9.8s or 1.0.0f, disable SSLv3 support. These OpenSSL
      versions have a bug (CVE-2011-4576) in which their block cipher
      padding includes uninitialized data, potentially leaking sensitive
      information to any peer with whom they make a SSLv3 connection. Tor
      does not use SSL v3 by default, but a hostile client or server
      could force an SSLv3 connection in order to gain information that
      they shouldn't have been able to get. The best solution here is to
      upgrade to OpenSSL 0.9.8s or 1.0.0f (or later). But when building
      or running with a non-upgraded OpenSSL, we disable SSLv3 entirely
      to make sure that the bug can't happen.
    - Never use a bridge or a controller-supplied node as an exit, even
      if its exit policy allows it. Found by wanoskarnet. Fixes bug
      5342. Bugfix on 0.1.1.15-rc (for controller-purpose descriptors)
      and 0.2.0.3-alpha (for bridge-purpose descriptors).
    - Only build circuits if we have a sufficient threshold of the total
      descriptors that are marked in the consensus with the "Exit"
      flag. This mitigates an attack proposed by wanoskarnet, in which
      all of a client's bridges collude to restrict the exit nodes that
      the client knows about. Fixes bug 5343.
    - Provide controllers with a safer way to implement the cookie
      authentication mechanism. With the old method, if another locally
      running program could convince a controller that it was the Tor
      process, then that program could trick the controller into telling
      it the contents of an arbitrary 32-byte file. The new "SAFECOOKIE"
      authentication method uses a challenge-response approach to prevent
      this attack. Fixes bug 5185; implements proposal 193.

  o Major bugfixes:
    - Avoid logging uninitialized data when unable to decode a hidden
      service descriptor cookie. Fixes bug 5647; bugfix on 0.2.1.5-alpha.
    - Avoid a client-side assertion failure when receiving an INTRODUCE2
      cell on a general purpose circuit. Fixes bug 5644; bugfix on
      0.2.1.6-alpha.
    - Fix builds when the path to sed, openssl, or sha1sum contains
      spaces, which is pretty common on Windows. Fixes bug 5065; bugfix
      on 0.2.2.1-alpha.
    - Correct our replacements for the timeradd() and timersub() functions
      on platforms that lack them (for example, Windows). The timersub()
      function is used when expiring circuits, while timeradd() is
      currently unused. Bug report and patch by Vektor. Fixes bug 4778;
      bugfix on 0.2.2.24-alpha.
    - Fix the SOCKET_OK test that we use to tell when socket
      creation fails so that it works on Win64. Fixes part of bug 4533;
      bugfix on 0.2.2.29-beta. Bug found by wanoskarnet.

  o Minor bugfixes:
    - Reject out-of-range times like 23:59:61 in parse_rfc1123_time().
      Fixes bug 5346; bugfix on 0.0.8pre3.
    - Make our number-parsing functions always treat too-large values
      as an error, even when those values exceed the width of the
      underlying type. Previously, if the caller provided these
      functions with minima or maxima set to the extreme values of the
      underlying integer type, these functions would return those
      values on overflow rather than treating overflow as an error.
      Fixes part of bug 5786; bugfix on 0.0.9.
    - Older Linux kernels erroneously respond to strange nmap behavior
      by having accept() return successfully with a zero-length
      socket. When this happens, just close the connection. Previously,
      we would try harder to learn the remote address: but there was
      no such remote address to learn, and our method for trying to
      learn it was incorrect. Fixes bugs 1240, 4745, and 4747. Bugfix
      on 0.1.0.3-rc. Reported and diagnosed by "r1eo".
    - Correct parsing of certain date types in parse_http_time().
      Without this patch, If-Modified-Since would behave
      incorrectly. Fixes bug 5346; bugfix on 0.2.0.2-alpha. Patch from
      Esteban Manchado Velázques.
    - Change the BridgePassword feature (part of the "bridge community"
      design, which is not yet implemented) to use a time-independent
      comparison. The old behavior might have allowed an adversary
      to use timing to guess the BridgePassword value. Fixes bug 5543;
      bugfix on 0.2.0.14-alpha.
    - Detect and reject certain misformed escape sequences in
      configuration values. Previously, these values would cause us
      to crash if received in a torrc file or over an authenticated
      control port. Bug found by Esteban Manchado Velázquez, and
      independently by Robert Connolly from Matta Consulting who further
      noted that it allows a post-authentication heap overflow. Patch
      by Alexander Schrijver. Fixes bugs 5090 and 5402 (CVE 2012-1668);
      bugfix on 0.2.0.16-alpha.
    - Fix a compile warning when using the --enable-openbsd-malloc
      configure option. Fixes bug 5340; bugfix on 0.2.0.20-rc.
    - During configure, detect when we're building with clang version
      3.0 or lower and disable the -Wnormalized=id and -Woverride-init
      CFLAGS. clang doesn't support them yet.
    - When sending an HTTP/1.1 proxy request, include a Host header.
      Fixes bug 5593; bugfix on 0.2.2.1-alpha.
    - Fix a NULL-pointer dereference on a badly formed SETCIRCUITPURPOSE
      command. Found by mikeyc. Fixes bug 5796; bugfix on 0.2.2.9-alpha.
    - If we hit the error case where routerlist_insert() replaces an
      existing (old) server descriptor, make sure to remove that
      server descriptor from the old_routers list. Fix related to bug
      1776. Bugfix on 0.2.2.18-alpha.

  o Minor bugfixes (documentation and log messages):
    - Fix a typo in a log message in rend_service_rendezvous_has_opened().
      Fixes bug 4856; bugfix on Tor 0.0.6.
    - Update "ClientOnly" man page entry to explain that there isn't
      really any point to messing with it. Resolves ticket 5005.
    - Document the GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays
      directory authority option (introduced in Tor 0.2.2.34).
    - Downgrade the "We're missing a certificate" message from notice
      to info: people kept mistaking it for a real problem, whereas it
      is seldom the problem even when we are failing to bootstrap. Fixes
      bug 5067; bugfix on 0.2.0.10-alpha.
    - Correctly spell "connect" in a log message on failure to create a
      controlsocket. Fixes bug 4803; bugfix on 0.2.2.26-beta.
    - Clarify the behavior of MaxCircuitDirtiness with hidden service
      circuits. Fixes issue 5259.

  o Minor features:
    - Directory authorities now reject versions of Tor older than
      0.2.1.30, and Tor versions between 0.2.2.1-alpha and 0.2.2.20-alpha
      inclusive. These versions accounted for only a small fraction of
      the Tor network, and have numerous known security issues. Resolves
      issue 4788.
    - Update to the May 1 2012 Maxmind GeoLite Country database.

  - Feature removal:
    - When sending or relaying a RELAY_EARLY cell, we used to convert
      it to a RELAY cell if the connection was using the v1 link
      protocol. This was a workaround for older versions of Tor, which
      didn't handle RELAY_EARLY cells properly. Now that all supported
      versions can handle RELAY_EARLY cells, and now that we're enforcing
      the "no RELAY_EXTEND commands except in RELAY_EARLY cells" rule,
      remove this workaround. Addresses bug 4786.


Changes in version 0.2.3.15-alpha - 2012-04-30
  Tor 0.2.3.15-alpha fixes a variety of smaller bugs, including making
  the development branch build on Windows again.

  o Minor bugfixes (on 0.2.2.x and earlier):
    - Make sure that there are no unhandled pending TLS errors before
      reading from a TLS stream. We had checks in 0.1.0.3-rc, but
      lost them in 0.1.0.5-rc when we refactored read_to_buf_tls().
      Bugfix on 0.1.0.5-rc; fixes bug 4528.
    - Fix an assert that directory authorities could trigger on sighup
      during some configuration state transitions. We now don't treat
      it as a fatal error when the new descriptor we just generated in
      init_keys() isn't accepted. Fixes bug 4438; bugfix on 0.2.1.9-alpha.
    - After we pick a directory mirror, we would refuse to use it if
      it's in our ExcludeExitNodes list, resulting in mysterious failures
      to bootstrap for people who just wanted to avoid exiting from
      certain locations. Fixes bug 5623; bugfix on 0.2.2.25-alpha.
    - When building with --enable-static-tor on OpenBSD, do not
      erroneously attempt to link -lrt. Fixes bug 5103.

  o Minor bugfixes (on 0.2.3.x):
    - When Tor is built with kernel headers from a recent (last few
      years) Linux kernel, do not fail to run on older (pre-2.6.28
      Linux kernels). Fixes bug 5112; bugfix on 0.2.3.1-alpha.
    - Fix cross-compilation issues with mingw. Bugfixes on 0.2.3.6-alpha
      and 0.2.3.12-alpha.
    - Fix compilation with miniupnpc version 1.6; patch from
      Anthony G. Basile. Fixes bug 5434; bugfix on 0.2.3.12-alpha.
    - Fix compilation with MSVC, which had defined MS_WINDOWS. Bugfix
      on 0.2.3.13-alpha; found and fixed by Gisle Vanem.
    - Fix compilation on platforms without unistd.h, or where environ
      is defined in stdlib.h. Fixes bug 5704; bugfix on 0.2.3.13-alpha.

  o Minor features:
    - Directory authorities are now a little more lenient at accepting
      older router descriptors, or newer router descriptors that don't
      make big changes. This should help ameliorate past and future
      issues where routers think they have uploaded valid descriptors,
      but the authorities don't think so. Fix for ticket 2479.
    - Make the code that clients use to detect an address change be
      IPv6-aware, so that it won't fill clients' logs with error
      messages when trying to get the IPv4 address of an IPv6
      connection. Implements ticket 5537.

  o Removed features:
    - Remove the GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays option;
      authorities needed to use it for a while to keep the network working
      as people upgraded to 0.2.1.31, 0.2.2.34, or 0.2.3.6-alpha, but
      that was six months ago. As of now, it should no longer be needed
      or used.


Changes in version 0.2.3.14-alpha - 2012-04-23
  Tor 0.2.3.14-alpha fixes yet more bugs to get us closer to a release
  candidate. It also dramatically speeds up AES: fast relays should
  consider switching to the newer OpenSSL library.

  o Directory authority changes:
    - Change IP address for ides (v3 directory authority), and rename
      it to turtles.

  o Major bugfixes:
    - Avoid logging uninitialized data when unable to decode a hidden
      service descriptor cookie. Fixes bug 5647; bugfix on 0.2.1.5-alpha.
    - Avoid a client-side assertion failure when receiving an INTRODUCE2
      cell on a general purpose circuit. Fixes bug 5644; bugfix on
      0.2.1.6-alpha.
    - If authorities are unable to get a v2 consensus document from other
      directory authorities, they no longer fall back to fetching
      them from regular directory caches. Fixes bug 5635; bugfix on
      0.2.2.26-beta, where routers stopped downloading v2 consensus
      documents entirely.
    - When we start a Tor client with a normal consensus already cached,
      be willing to download a microdescriptor consensus. Fixes bug 4011;
      fix on 0.2.3.1-alpha.

  o Major features (performance):
    - When built to use OpenSSL 1.0.1, and built for an x86 or x86_64
      instruction set, take advantage of OpenSSL's AESNI, bitsliced, or
      vectorized AES implementations as appropriate. These can be much,
      much faster than other AES implementations.

  o Minor bugfixes (0.2.2.x and earlier):
    - Don't launch more than 10 service-side introduction-point circuits
      for a hidden service in five minutes. Previously, we would consider
      launching more introduction-point circuits if at least one second
      had passed without any introduction-point circuits failing. Fixes
      bug 4607; bugfix on 0.0.7pre1.
    - Change the BridgePassword feature (part of the "bridge community"
      design, which is not yet implemented) to use a time-independent
      comparison. The old behavior might have allowed an adversary
      to use timing to guess the BridgePassword value. Fixes bug 5543;
      bugfix on 0.2.0.14-alpha.
    - Enforce correct return behavior of tor_vsscanf() when the '%%'
      pattern is used. Fixes bug 5558. Bugfix on 0.2.1.13.
    - When sending an HTTP/1.1 proxy request, include a Host header.
      Fixes bug 5593; bugfix on 0.2.2.1-alpha.
    - Don't log that we have "decided to publish new relay descriptor"
      unless we are actually publishing a descriptor. Fixes bug 3942;
      bugfix on 0.2.2.28-beta.

  o Minor bugfixes (0.2.3.x):
    - Fix a bug where a bridge authority crashes (on a failed assert)
      if it has seen no directory requests when it's time to write
      statistics to disk. Fixes bug 5508. Bugfix on 0.2.3.6-alpha.
    - Fix bug stomping on ORPort option NoListen and ignoring option
      NoAdvertise. Fixes bug 5151; bugfix on 0.2.3.9-alpha.
    - In the testsuite, provide a large enough buffer in the tor_sscanf
      unit test. Otherwise we'd overrun that buffer and crash during
      the unit tests. Found by weasel. Fixes bug 5449; bugfix on
      0.2.3.12-alpha.
    - Make sure we create the keys directory if it doesn't exist and we're
      about to store the dynamic Diffie-Hellman parameters. Fixes bug
      5572; bugfix on 0.2.3.13-alpha.
    - Fix a small memory leak when trying to decode incorrect base16
      authenticator during SAFECOOKIE authentication. Found by
      Coverity Scan. Fixes CID 507. Bugfix on 0.2.3.13-alpha.

  o Minor features:
    - Add more information to a log statement that might help track down
      bug 4091. If you're seeing "Bug: tor_addr_is_internal() called with a
      non-IP address" messages (or any Bug messages, for that matter!),
      please let us know about it.
    - Relays now understand an IPv6 address when they get one from a
      directory server. Resolves ticket 4875.
    - Resolve IPv6 addresses in bridge and entry statistics to country
      code "??" which means we at least count them. Resolves ticket 5053;
      improves on 0.2.3.9-alpha.
    - Update to the April 3 2012 Maxmind GeoLite Country database.
    - Begin a doc/state-contents.txt file to explain the contents of
      the Tor state file. Fixes bug 2987.

  o Default torrc changes:
    - Stop listing "socksport 9050" in torrc.sample. We open a socks
      port on 9050 by default anyway, so this should not change anything
      in practice.
    - Stop mentioning the deprecated *ListenAddress options in
      torrc.sample. Fixes bug 5438.
    - Document unit of bandwidth related options in sample torrc.
      Fixes bug 5621.

  o Removed features:
    - The "torify" script no longer supports the "tsocks" socksifier
      tool, since tsocks doesn't support DNS and UDP right for Tor.
      Everyone should be using torsocks instead. Fixes bugs 3530 and
      5180. Based on a patch by "ugh".

  o Code refactoring:
    - Change the symmetric cipher interface so that creating and
      initializing a stream cipher are no longer separate functions.
    - Remove all internal support for unpadded RSA. We never used it, and
      it would be a bad idea to start.


Changes in version 0.2.3.13-alpha - 2012-03-26
  Tor 0.2.3.13-alpha fixes a variety of stability and correctness bugs
  in managed pluggable transports, as well as providing other cleanups
  that get us closer to a release candidate.

  o Directory authority changes:
    - Change IP address for maatuska (v3 directory authority).

  o Security fixes:
    - Provide controllers with a safer way to implement the cookie
      authentication mechanism. With the old method, if another locally
      running program could convince a controller that it was the Tor
      process, then that program could trick the controller into telling
      it the contents of an arbitrary 32-byte file. The new "SAFECOOKIE"
      authentication method uses a challenge-response approach to prevent
      this attack. Fixes bug 5185, implements proposal 193.
    - Never use a bridge or a controller-supplied node as an exit, even
      if its exit policy allows it. Found by wanoskarnet. Fixes bug
      5342. Bugfix on 0.1.1.15-rc (for controller-purpose descriptors)
      and 0.2.0.3-alpha (for bridge-purpose descriptors).
    - Only build circuits if we have a sufficient threshold of the total
      descriptors that are marked in the consensus with the "Exit"
      flag. This mitigates an attack proposed by wanoskarnet, in which
      all of a client's bridges collude to restrict the exit nodes that
      the client knows about. Fixes bug 5343.

  o Major bugfixes (on Tor 0.2.3.x):
    - Avoid an assert when managed proxies like obfsproxy are configured,
      and we receive HUP signals or setconf attempts too rapidly. This
      situation happens most commonly when Vidalia tries to attach to
      Tor or tries to configure the Tor it's attached to. Fixes bug 5084;
      bugfix on 0.2.3.6-alpha.
    - Fix a relay-side pluggable transports bug where managed proxies were
      unreachable from the Internet, because Tor asked them to bind on
      localhost. Fixes bug 4725; bugfix on 0.2.3.9-alpha.
    - Stop discarding command-line arguments when TestingTorNetwork
      is set. Discovered by Kevin Bauer. Fixes bug 5373; bugfix on
      0.2.3.9-alpha, where task 4552 added support for two layers of
      torrc files.
    - Resume allowing the unit tests to run in gdb. This was accidentally
      made impossible when the DisableDebuggerAttachment option was
      introduced. Fixes bug 5448; bugfix on 0.2.3.9-alpha.
    - Resume building with nat-pmp support. Fixes bug 4955; bugfix on
      0.2.3.11-alpha. Reported by Anthony G. Basile.

  o Minor bugfixes (on 0.2.2.x and earlier):
    - Ensure we don't cannibalize circuits that are longer than three hops
      already, so we don't end up making circuits with 5 or more
      hops. Patch contributed by wanoskarnet. Fixes bug 5231; bugfix on
      0.1.0.1-rc which introduced cannibalization.
    - Detect and reject certain misformed escape sequences in
      configuration values. Previously, these values would cause us
      to crash if received in a torrc file or over an authenticated
      control port. Bug found by Esteban Manchado Velázquez, and
      independently by Robert Connolly from Matta Consulting who further
      noted that it allows a post-authentication heap overflow. Patch
      by Alexander Schrijver. Fixes bugs 5090 and 5402 (CVE 2012-1668);
      bugfix on 0.2.0.16-alpha.
    - Fix a compile warning when using the --enable-openbsd-malloc
      configure option. Fixes bug 5340; bugfix on 0.2.0.20-rc.
    - Directory caches no longer refuse to clean out descriptors because
      of missing v2 networkstatus documents, unless they're configured
      to retrieve v2 networkstatus documents. Fixes bug 4838; bugfix on
      0.2.2.26-beta. Patch by Daniel Bryg.
    - Update to the latest version of the tinytest unit testing framework.
      This includes a couple of bugfixes that can be relevant for
      running forked unit tests on Windows, and removes all reserved
      identifiers.

  o Minor bugfixes (on 0.2.3.x):
    - On a failed pipe() call, don't leak file descriptors. Fixes bug
      4296; bugfix on 0.2.3.1-alpha.
    - Spec conformance: on a v3 handshake, do not send a NETINFO cell
      until after we have received a CERTS cell. Fixes bug 4361; bugfix
      on 0.2.3.6-alpha. Patch by "frosty".
    - When binding to an IPv6 address, set the IPV6_V6ONLY socket
      option, so that the IP stack doesn't decide to use it for IPv4
      too. Fixes bug 4760; bugfix on 0.2.3.9-alpha.
    - Ensure that variables set in Tor's environment cannot override
      environment variables that Tor passes to a managed
      pluggable-transport proxy. Previously, Tor would pass every
      variable in its environment to managed proxies along with the new
      ones, in such a way that on many operating systems, the inherited
      environment variables would override those which Tor tried to
      explicitly set. Bugfix on 0.2.3.12-alpha for most Unixoid systems;
      bugfix on 0.2.3.9-alpha for Windows.

  o Minor features:
    - A wide variety of new unit tests by Esteban Manchado Velázquez.
    - Shorten links in the tor-exit-notice file. Patch by Christian Kujau.
    - Update to the March 6 2012 Maxmind GeoLite Country database.


Changes in version 0.2.3.12-alpha - 2012-02-13
  Tor 0.2.3.12-alpha lets fast exit relays scale better, allows clients
  to use bridges that run Tor 0.2.2.x, and resolves several big bugs
  when Tor is configured to use a pluggable transport like obfsproxy.

  o Major bugfixes:
    - Fix builds when the path to sed, openssl, or sha1sum contains
      spaces, which is pretty common on Windows. Fixes bug 5065; bugfix
      on 0.2.2.1-alpha.
    - Set the SO_REUSEADDR socket option before we call bind() on outgoing
      connections. This change should allow busy exit relays to stop
      running out of available sockets as quickly. Fixes bug 4950;
      bugfix on 0.2.2.26-beta.
    - Allow 0.2.3.x clients to use 0.2.2.x bridges. Previously the client
      would ask the bridge for microdescriptors, which are only supported
      in 0.2.3.x, and then fail to bootstrap when it didn't get the
      answers it wanted. Fixes bug 4013; bugfix on 0.2.3.2-alpha.
    - Properly set up obfsproxy's environment when in managed mode. The
      Tor Browser Bundle needs LD_LIBRARY_PATH to be passed to obfsproxy,
      and when you run your Tor as a daemon, there's no HOME. Fixes bugs
      5076 and 5082; bugfix on 0.2.3.6-alpha.

  o Minor features:
    - Use the dead_strip option when building Tor on OS X. This reduces
      binary size by almost 19% when linking openssl and libevent
      statically, which we do for Tor Browser Bundle.
    - Fix broken URLs in the sample torrc file, and tell readers about
      the OutboundBindAddress, ExitPolicyRejectPrivate, and
      PublishServerDescriptor options. Addresses bug 4652.
    - Update to the February 7 2012 Maxmind GeoLite Country database.

  o Minor bugfixes:
    - Downgrade the "We're missing a certificate" message from notice
      to info: people kept mistaking it for a real problem, whereas it
      is seldom the problem even when we are failing to bootstrap. Fixes
      bug 5067; bugfix on 0.2.0.10-alpha.
    - Don't put "TOR_PT_EXTENDED_SERVER_PORT=127.0.0.1:4200" in a
      managed pluggable transport server proxy's environment.
      Previously, we would put it there, even though Tor doesn't
      implement an 'extended server port' yet, and even though Tor
      almost certainly isn't listening at that address. For now, we set
      it to an empty string to avoid crashing older obfsproxies. Bugfix
      on 0.2.3.6-alpha.
    - Log the heartbeat message every HeartbeatPeriod seconds, not every
      HeartbeatPeriod + 1 seconds. Fixes bug 4942; bugfix on
      0.2.3.1-alpha. Bug reported by Scott Bennett.
    - Calculate absolute paths correctly on Windows. Fixes bug 4973;
      bugfix on 0.2.3.11-alpha.
    - Update "ClientOnly" man page entry to explain that there isn't
      really any point to messing with it. Resolves ticket 5005.
    - Use the correct CVE number for CVE-2011-4576 in our comments and
      log messages. Found by "fermenthor". Resolves bug 5066; bugfix on
      0.2.3.11-alpha.

  o Code simplifications and refactoring:
    - Use the _WIN32 macro throughout our code to detect Windows.
      (Previously we had used the obsolete 'WIN32' and the idiosyncratic
      'MS_WINDOWS'.)


Changes in version 0.2.3.11-alpha - 2012-01-22
  Tor 0.2.3.11-alpha marks feature-freeze for the 0.2.3 tree. It deploys
  the last step of the plan to limit maximum circuit length, includes
  a wide variety of hidden service performance and correctness fixes,
  works around an OpenSSL security flaw if your distro is too stubborn
  to upgrade, and fixes a bunch of smaller issues.

  o Major features:
    - Now that Tor 0.2.0.x is completely deprecated, enable the final
      part of "Proposal 110: Avoiding infinite length circuits" by
      refusing all circuit-extend requests that do not use a relay_early
      cell. This change helps Tor resist a class of denial-of-service
      attacks by limiting the maximum circuit length.
    - Adjust the number of introduction points that a hidden service
      will try to maintain based on how long its introduction points
      remain in use and how many introductions they handle. Fixes
      part of bug 3825.
    - Try to use system facilities for enumerating local interface
      addresses, before falling back to our old approach (which was
      binding a UDP socket, and calling getsockname() on it). That
      approach was scaring OS X users whose draconian firewall
      software warned about binding to UDP sockets, regardless of
      whether packets were sent. Now we try to use getifaddrs(),
      SIOCGIFCONF, or GetAdaptersAddresses(), depending on what the
      system supports. Resolves ticket 1827.

  o Major security workaround:
    - When building or running with any version of OpenSSL earlier
      than 0.9.8s or 1.0.0f, disable SSLv3 support. These OpenSSL
      versions have a bug (CVE-2011-4576) in which their block cipher
      padding includes uninitialized data, potentially leaking sensitive
      information to any peer with whom they make a SSLv3 connection. Tor
      does not use SSL v3 by default, but a hostile client or server
      could force an SSLv3 connection in order to gain information that
      they shouldn't have been able to get. The best solution here is to
      upgrade to OpenSSL 0.9.8s or 1.0.0f (or later). But when building
      or running with a non-upgraded OpenSSL, we disable SSLv3 entirely
      to make sure that the bug can't happen.

  o Major bugfixes:
    - Fix the SOCKET_OK test that we use to tell when socket
      creation fails so that it works on Win64. Fixes part of bug 4533;
      bugfix on 0.2.2.29-beta. Bug found by wanoskarnet.
    - Correct our replacements for the timeradd() and timersub() functions
      on platforms that lack them (for example, Windows). The timersub()
      function is used when expiring circuits, while timeradd() is
      currently unused. Bug report and patch by Vektor. Fixes bug 4778;
      bugfix on 0.2.2.24-alpha and 0.2.3.1-alpha.
    - Do not use OpenSSL 1.0.0's counter mode: it has a critical bug
      that was fixed in OpenSSL 1.0.0a. We test for the counter mode
      bug at runtime, not compile time, because some distributions hack
      their OpenSSL to mis-report its version. Fixes bug 4779; bugfix
      on 0.2.3.9-alpha. Found by Pascal.

  o Minor features (controller):
    - Use absolute path names when reporting the torrc filename in the
      control protocol, so a controller can more easily find the torrc
      file. Resolves bug 1101.
    - Extend the control protocol to report flags that control a circuit's
      path selection in CIRC events and in replies to 'GETINFO
      circuit-status'. Implements part of ticket 2411.
    - Extend the control protocol to report the hidden service address
      and current state of a hidden-service-related circuit in CIRC
      events and in replies to 'GETINFO circuit-status'. Implements part
      of ticket 2411.
    - When reporting the path to the cookie file to the controller,
      give an absolute path. Resolves ticket 4881.
    - Allow controllers to request an event notification whenever a
      circuit is cannibalized or its purpose is changed. Implements
      part of ticket 3457.
    - Include the creation time of a circuit in CIRC and CIRC2
      control-port events and the list produced by the 'GETINFO
      circuit-status' control-port command.

  o Minor features (directory authorities):
    - Directory authorities now reject versions of Tor older than
      0.2.1.30, and Tor versions between 0.2.2.1-alpha and 0.2.2.20-alpha
      inclusive. These versions accounted for only a small fraction of
      the Tor network, and have numerous known security issues. Resolves
      issue 4788.
    - Authority operators can now vote for all relays in a given
      set of countries to be BadDir/BadExit/Invalid/Rejected.
    - Provide two consensus parameters (FastFlagMinThreshold and
      FastFlagMaxThreshold) to control the range of allowable bandwidths
      for the Fast directory flag. These allow authorities to run
      experiments on appropriate requirements for being a "Fast" node.
      The AuthDirFastGuarantee config value still applies. Implements
      ticket 3946.
    - Document the GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays
      directory authority option (introduced in Tor 0.2.2.34).

  o Minor features (other):
    - Don't disable the DirPort when we cannot exceed our AccountingMax
      limit during this interval because the effective bandwidthrate is
      low enough. This is useful in a situation where AccountMax is only
      used as an additional safeguard or to provide statistics.
    - Prepend an informative header to generated dynamic_dh_params files.
    - If EntryNodes are given, but UseEntryGuards is set to 0, warn that
      EntryNodes will have no effect. Resolves issue 2571.
    - Log more useful messages when we fail to disable debugger
      attachment.
    - Log which authority we're missing votes from when we go to fetch
      them from the other auths.
    - Log (at debug level) whenever a circuit's purpose is changed.
    - Add missing documentation for the MaxClientCircuitsPending,
      UseMicrodescriptors, UserspaceIOCPBuffers, and
      _UseFilteringSSLBufferevents options, all introduced during
      the 0.2.3.x series.
    - Update to the January 3 2012 Maxmind GeoLite Country database.

  o Minor bugfixes (hidden services):
    - Don't close hidden service client circuits which have almost
      finished connecting to their destination when they reach
      the normal circuit-build timeout. Previously, we would close
      introduction circuits which are waiting for an acknowledgement
      from the introduction point, and rendezvous circuits which have
      been specified in an INTRODUCE1 cell sent to a hidden service,
      after the normal CBT. Now, we mark them as 'timed out', and launch
      another rendezvous attempt in parallel. This behavior change can
      be disabled using the new CloseHSClientCircuitsImmediatelyOnTimeout
      option. Fixes part of bug 1297; bugfix on 0.2.2.2-alpha.
    - Don't close hidden-service-side rendezvous circuits when they
      reach the normal circuit-build timeout. This behavior change can
      be disabled using the new
      CloseHSServiceRendCircuitsImmediatelyOnTimeout option. Fixes the
      remaining part of bug 1297; bugfix on 0.2.2.2-alpha.
    - Make sure we never mark the wrong rendezvous circuit as having
      had its introduction cell acknowleged by the introduction-point
      relay. Previously, when we received an INTRODUCE_ACK cell on a
      client-side hidden-service introduction circuit, we might have
      marked a rendezvous circuit other than the one we specified in
      the INTRODUCE1 cell as INTRO_ACKED, which would have produced
      a warning message and interfered with the hidden service
      connection-establishment process. Fixes bug 4759; bugfix on
      0.2.3.3-alpha, when we added the stream-isolation feature which
      might cause Tor to open multiple rendezvous circuits for the same
      hidden service.
    - Don't trigger an assertion failure when we mark a new client-side
      hidden-service introduction circuit for close during the process
      of creating it. Fixes bug 4796; bugfix on 0.2.3.6-alpha. Reported
      by murb.

  o Minor bugfixes (log messages):
    - Correctly spell "connect" in a log message on failure to create a
      controlsocket. Fixes bug 4803; bugfix on 0.2.2.26-beta and
      0.2.3.2-alpha.
    - Fix a typo in a log message in rend_service_rendezvous_has_opened().
      Fixes bug 4856; bugfix on Tor 0.0.6.
    - Fix the log message describing how we work around discovering
      that our version is the ill-fated OpenSSL 0.9.8l. Fixes bug
      4837; bugfix on 0.2.2.9-alpha.
    - When logging about a disallowed .exit name, do not also call it
      an "invalid onion address". Fixes bug 3325; bugfix on 0.2.2.9-alpha.

  o Minor bugfixes (build fixes):
    - During configure, detect when we're building with clang version
      3.0 or lower and disable the -Wnormalized=id and -Woverride-init
      CFLAGS. clang doesn't support them yet.
    - During configure, search for library containing cos function as
      libm lives in libcore on some platforms (BeOS/Haiku). Linking
      against libm was hard-coded before. Fixes the first part of bug
      4727; bugfix on 0.2.2.2-alpha. Patch and analysis by Martin Hebnes
      Pedersen.
    - Detect attempts to build Tor on (as yet hypothetical) versions
      of Windows where sizeof(intptr_t) != sizeof(SOCKET). Partial
      fix for bug 4533. Bugfix on 0.2.2.28-beta.
    - Preprocessor directives should not be put inside the arguments
      of a macro. This would break compilation with GCC releases prior
      to version 3.3. We would never recommend such an old GCC version,
      but it is apparently required for binary compatibility on some
      platforms (namely, certain builds of Haiku). Fixes the other part
      of bug 4727; bugfix on 0.2.3.3-alpha. Patch and analysis by Martin
      Hebnes Pedersen.

  o Minor bugfixes (other):
    - Older Linux kernels erroneously respond to strange nmap behavior
      by having accept() return successfully with a zero-length
      socket. When this happens, just close the connection. Previously,
      we would try harder to learn the remote address: but there was
      no such remote address to learn, and our method for trying to
      learn it was incorrect. Fixes bugs 1240, 4745, and 4747. Bugfix
      on 0.1.0.3-rc. Reported and diagnosed by "r1eo".
    - Fix null-pointer access that could occur if TLS allocation failed.
      Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un". This was
      erroneously listed as fixed in 0.2.3.9-alpha, but the fix had
      accidentally been reverted.
    - Fix our implementation of crypto_random_hostname() so it can't
      overflow on ridiculously large inputs. (No Tor version has ever
      provided this kind of bad inputs, but let's be correct in depth.)
      Fixes bug 4413; bugfix on 0.2.2.9-alpha. Fix by Stephen Palmateer.
    - Find more places in the code that should have been testing for
      invalid sockets using the SOCKET_OK macro. Required for a fix
      for bug 4533. Bugfix on 0.2.2.28-beta.
    - Fix an assertion failure when, while running with bufferevents, a
      connection finishes connecting after it is marked for close, but
      before it is closed. Fixes bug 4697; bugfix on 0.2.3.1-alpha.
    - test_util_spawn_background_ok() hardcoded the expected value
      for ENOENT to 2. This isn't portable as error numbers are
      platform specific, and particularly the hurd has ENOENT at
      0x40000002. Construct expected string at runtime, using the correct
      value for ENOENT. Fixes bug 4733; bugfix on 0.2.3.1-alpha.
    - Reject attempts to disable DisableDebuggerAttachment while Tor is
      running. Fixes bug 4650; bugfix on 0.2.3.9-alpha.
    - Use an appropriate-width type for sockets in tor-fw-helper on
      win64. Fixes bug 1983 at last. Bugfix on 0.2.3.9-alpha.

  o Feature removal:
    - When sending or relaying a RELAY_EARLY cell, we used to convert
      it to a RELAY cell if the connection was using the v1 link
      protocol. This was a workaround for older versions of Tor, which
      didn't handle RELAY_EARLY cells properly. Now that all supported
      versions can handle RELAY_EARLY cells, and now that we're enforcing
      the "no RELAY_EXTEND commands except in RELAY_EARLY cells" rule,
      remove this workaround. Addresses bug 4786.

  o Code simplifications and refactoring:
    - Use OpenSSL's built-in SSL_state_string_long() instead of our
      own homebrewed ssl_state_to_string() replacement. Patch from
      Emile Snyder. Fixes bug 4653.
    - Use macros to indicate OpenSSL versions, so we don't need to worry
      about accidental hexadecimal bit shifts.
    - Remove some workaround code for OpenSSL 0.9.6 (which is no longer
      supported).
    - Convert more instances of tor_snprintf+tor_strdup into tor_asprintf.
    - Use the smartlist_add_asprintf() alias more consistently.
    - Use a TOR_INVALID_SOCKET macro when initializing a socket to an
      invalid value, rather than just -1.
    - Rename a handful of old identifiers, mostly related to crypto
      structures and crypto functions. By convention, our "create an
      object" functions are called "type_new()", our "free an object"
      functions are called "type_free()", and our types indicate that
      they are types only with a final "_t". But a handful of older
      types and functions broke these rules, with function names like
      "type_create" or "subsystem_op_type", or with type names like
      type_env_t.


Changes in version 0.2.3.10-alpha - 2011-12-16
  Tor 0.2.3.10-alpha fixes a critical heap-overflow security issue in
  Tor's buffers code. Absolutely everybody should upgrade.

  The bug relied on an incorrect calculation when making data continuous
  in one of our IO buffers, if the first chunk of the buffer was
  misaligned by just the wrong amount. The miscalculation would allow an
  attacker to overflow a piece of heap-allocated memory. To mount this
  attack, the attacker would need to either open a SOCKS connection to
  Tor's SocksPort (usually restricted to localhost), or target a Tor
  instance configured to make its connections through a SOCKS proxy
  (which Tor does not do by default).

  Good security practice requires that all heap-overflow bugs should be
  presumed to be exploitable until proven otherwise, so we are treating
  this as a potential code execution attack. Please upgrade immediately!
  This bug does not affect bufferevents-based builds of Tor. Special
  thanks to "Vektor" for reporting this issue to us!

  This release also contains a few minor bugfixes for issues discovered
  in 0.2.3.9-alpha.

  o Major bugfixes:
    - Fix a heap overflow bug that could occur when trying to pull
      data into the first chunk of a buffer, when that chunk had
      already had some data drained from it. Fixes CVE-2011-2778;
      bugfix on 0.2.0.16-alpha. Reported by "Vektor".

  o Minor bugfixes:
    - If we can't attach streams to a rendezvous circuit when we
      finish connecting to a hidden service, clear the rendezvous
      circuit's stream-isolation state and try to attach streams
      again. Previously, we cleared rendezvous circuits' isolation
      state either too early (if they were freshly built) or not at all
      (if they had been built earlier and were cannibalized). Bugfix on
      0.2.3.3-alpha; fixes bug 4655.
    - Fix compilation of the libnatpmp helper on non-Windows. Bugfix on
      0.2.3.9-alpha; fixes bug 4691. Reported by Anthony G. Basile.
    - Fix an assertion failure when a relay with accounting enabled
      starts up while dormant. Fixes bug 4702; bugfix on 0.2.3.9-alpha.

  o Minor features:
    - Update to the December 6 2011 Maxmind GeoLite Country database.


Changes in version 0.2.2.35 - 2011-12-16
  Tor 0.2.2.35 fixes a critical heap-overflow security issue in Tor's
  buffers code. Absolutely everybody should upgrade.

  The bug relied on an incorrect calculation when making data continuous
  in one of our IO buffers, if the first chunk of the buffer was
  misaligned by just the wrong amount. The miscalculation would allow an
  attacker to overflow a piece of heap-allocated memory. To mount this
  attack, the attacker would need to either open a SOCKS connection to
  Tor's SocksPort (usually restricted to localhost), or target a Tor
  instance configured to make its connections through a SOCKS proxy
  (which Tor does not do by default).

  Good security practice requires that all heap-overflow bugs should be
  presumed to be exploitable until proven otherwise, so we are treating
  this as a potential code execution attack. Please upgrade immediately!
  This bug does not affect bufferevents-based builds of Tor. Special
  thanks to "Vektor" for reporting this issue to us!

  Tor 0.2.2.35 also fixes several bugs in previous versions, including
  crash bugs for unusual configurations, and a long-term bug that
  would prevent Tor from starting on Windows machines with draconian
  AV software.

  With this release, we remind everyone that 0.2.0.x has reached its
  formal end-of-life. Those Tor versions have many known flaws, and
  nobody should be using them. You should upgrade -- ideally to the
  0.2.2.x series. If you're using a Linux or BSD and its packages are
  obsolete, stop using those packages and upgrade anyway.

  The Tor 0.2.1.x series is also approaching its end-of-life: it will no
  longer receive support after some time in early 2012.

  o Major bugfixes:
    - Fix a heap overflow bug that could occur when trying to pull
      data into the first chunk of a buffer, when that chunk had
      already had some data drained from it. Fixes CVE-2011-2778;
      bugfix on 0.2.0.16-alpha. Reported by "Vektor".
    - Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so
      that it doesn't attempt to allocate a socketpair. This could cause
      some problems on Windows systems with overzealous firewalls. Fix for
      bug 4457; workaround for Libevent versions 2.0.1-alpha through
      2.0.15-stable.
    - If we mark an OR connection for close based on a cell we process,
      don't process any further cells on it. We already avoid further
      reads on marked-for-close connections, but now we also discard the
      cells we'd already read. Fixes bug 4299; bugfix on 0.2.0.10-alpha,
      which was the first version where we might mark a connection for
      close based on processing a cell on it.
    - Correctly sanity-check that we don't underflow on a memory
      allocation (and then assert) for hidden service introduction
      point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
      bugfix on 0.2.1.5-alpha.
    - Fix a memory leak when we check whether a hidden service
      descriptor has any usable introduction points left. Fixes bug
      4424. Bugfix on 0.2.2.25-alpha.
    - Don't crash when we're running as a relay and don't have a GeoIP
      file. Bugfix on 0.2.2.34; fixes bug 4340. This backports a fix
      we've had in the 0.2.3.x branch already.
    - When running as a client, do not print a misleading (and plain
      wrong) log message that we're collecting "directory request"
      statistics: clients don't collect statistics. Also don't create a
      useless (because empty) stats file in the stats/ directory. Fixes
      bug 4353; bugfix on 0.2.2.34.

  o Minor bugfixes:
    - Detect failure to initialize Libevent. This fix provides better
      detection for future instances of bug 4457.
    - Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers
      function. This was eating up hideously large amounts of time on some
      busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
    - Resolve an integer overflow bug in smartlist_ensure_capacity().
      Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by
      Mansour Moufid.
    - Don't warn about unused log_mutex in log.c when building with
      --disable-threads using a recent GCC. Fixes bug 4437; bugfix on
      0.1.0.6-rc which introduced --disable-threads.
    - When configuring, starting, or stopping an NT service, stop
      immediately after the service configuration attempt has succeeded
      or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
    - When sending a NETINFO cell, include the original address
      received for the other side, not its canonical address. Found
      by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
    - Fix a typo in a hibernation-related log message. Fixes bug 4331;
      bugfix on 0.2.2.23-alpha; found by "tmpname0901".
    - Fix a memory leak in launch_direct_bridge_descriptor_fetch() that
      occurred when a client tried to fetch a descriptor for a bridge
      in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.
    - Backport fixes for a pair of compilation warnings on Windows.
      Fixes bug 4521; bugfix on 0.2.2.28-beta and on 0.2.2.29-beta.
    - If we had ever tried to call tor_addr_to_str on an address of
      unknown type, we would have done a strdup on an uninitialized
      buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha.
      Reported by "troll_un".
    - Correctly detect and handle transient lookup failures from
      tor_addr_lookup. Fixes bug 4530; bugfix on 0.2.1.5-alpha.
      Reported by "troll_un".
    - Fix null-pointer access that could occur if TLS allocation failed.
      Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
    - Use tor_socket_t type for listener argument to accept(). Fixes bug
      4535; bugfix on 0.2.2.28-beta. Found by "troll_un".

  o Minor features:
    - Add two new config options for directory authorities:
      AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the
      Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold
      that is always sufficient to satisfy the bandwidth requirement for
      the Guard flag. Now it will be easier for researchers to simulate
      Tor networks with different values. Resolves ticket 4484.
    - When Tor ignores a hidden service specified in its configuration,
      include the hidden service's directory in the warning message.
      Previously, we would only tell the user that some hidden service
      was ignored. Bugfix on 0.0.6; fixes bug 4426.
    - Update to the December 6 2011 Maxmind GeoLite Country database.

  o Packaging changes:
    - Make it easier to automate expert package builds on Windows,
      by removing an absolute path from makensis.exe command.


Changes in version 0.2.1.32 - 2011-12-16
  Tor 0.2.1.32 backports important security and privacy fixes for
  oldstable. This release is intended only for package maintainers and
  others who cannot use the 0.2.2 stable series. All others should be
  using Tor 0.2.2.x or newer.

  The Tor 0.2.1.x series will reach formal end-of-life some time in
  early 2012; we will stop releasing patches for it then.

  o Major bugfixes (also included in 0.2.2.x):
    - Correctly sanity-check that we don't underflow on a memory
      allocation (and then assert) for hidden service introduction
      point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
      bugfix on 0.2.1.5-alpha.
    - Fix a heap overflow bug that could occur when trying to pull
      data into the first chunk of a buffer, when that chunk had
      already had some data drained from it. Fixes CVE-2011-2778;
      bugfix on 0.2.0.16-alpha. Reported by "Vektor".

  o Minor features:
    - Update to the December 6 2011 Maxmind GeoLite Country database.


Changes in version 0.2.3.9-alpha - 2011-12-08
  Tor 0.2.3.9-alpha introduces initial IPv6 support for bridges, adds
  a "DisableNetwork" security feature that bundles can use to avoid
  touching the network until bridges are configured, moves forward on
  the pluggable transport design, fixes a flaw in the hidden service
  design that unnecessarily prevented clients with wrong clocks from
  reaching hidden services, and fixes a wide variety of other issues.

  o Major features:
    - Clients can now connect to private bridges over IPv6. Bridges
      still need at least one IPv4 address in order to connect to
      other relays. Note that we don't yet handle the case where the
      user has two bridge lines for the same bridge (one IPv4, one
      IPv6). Implements parts of proposal 186.
    - New "DisableNetwork" config option to prevent Tor from launching any
      connections or accepting any connections except on a control port.
      Bundles and controllers can set this option before letting Tor talk
      to the rest of the network, for example to prevent any connections
      to a non-bridge address. Packages like Orbot can also use this
      option to instruct Tor to save power when the network is off.
    - Clients and bridges can now be configured to use a separate
      "transport" proxy. This approach makes the censorship arms race
      easier by allowing bridges to use protocol obfuscation plugins. It
      implements the "managed proxy" part of proposal 180 (ticket 3472).
    - When using OpenSSL 1.0.0 or later, use OpenSSL's counter mode
      implementation. It makes AES_CTR about 7% faster than our old one
      (which was about 10% faster than the one OpenSSL used to provide).
      Resolves ticket 4526.
    - Add a "tor2web mode" for clients that want to connect to hidden
      services non-anonymously (and possibly more quickly). As a safety
      measure to try to keep users from turning this on without knowing
      what they are doing, tor2web mode must be explicitly enabled at
      compile time, and a copy of Tor compiled to run in tor2web mode
      cannot be used as a normal Tor client. Implements feature 2553.
    - Add experimental support for running on Windows with IOCP and no
      kernel-space socket buffers. This feature is controlled by a new
      "UserspaceIOCPBuffers" config option (off by default), which has
      no effect unless Tor has been built with support for bufferevents,
      is running on Windows, and has enabled IOCP. This may, in the long
      run, help solve or mitigate bug 98.
    - Use a more secure consensus parameter voting algorithm. Now at
      least three directory authorities or a majority of them must
      vote on a given parameter before it will be included in the
      consensus. Implements proposal 178.

  o Major bugfixes:
    - Hidden services now ignore the timestamps on INTRODUCE2 cells.
      They used to check that the timestamp was within 30 minutes
      of their system clock, so they could cap the size of their
      replay-detection cache, but that approach unnecessarily refused
      service to clients with wrong clocks. Bugfix on 0.2.1.6-alpha, when
      the v3 intro-point protocol (the first one which sent a timestamp
      field in the INTRODUCE2 cell) was introduced; fixes bug 3460.
    - Only use the EVP interface when AES acceleration is enabled,
      to avoid a 5-7% performance regression. Resolves issue 4525;
      bugfix on 0.2.3.8-alpha.

  o Privacy/anonymity features (bridge detection):
    - Make bridge SSL certificates a bit more stealthy by using random
      serial numbers, in the same fashion as OpenSSL when generating
      self-signed certificates. Implements ticket 4584.
    - Introduce a new config option "DynamicDHGroups", enabled by
      default, which provides each bridge with a unique prime DH modulus
      to be used during SSL handshakes. This option attempts to help
      against censors who might use the Apache DH modulus as a static
      identifier for bridges. Addresses ticket 4548.

  o Minor features (new/different config options):
    - New configuration option "DisableDebuggerAttachment" (on by default)
      to prevent basic debugging attachment attempts by other processes.
      Supports Mac OS X and Gnu/Linux. Resolves ticket 3313.
    - Allow MapAddress directives to specify matches against super-domains,
      as in "MapAddress *.torproject.org *.torproject.org.torserver.exit".
      Implements issue 933.
    - Slightly change behavior of "list" options (that is, config
      options that can appear more than once) when they appear both in
      torrc and on the command line. Previously, the command-line options
      would be appended to the ones from torrc. Now, the command-line
      options override the torrc options entirely. This new behavior
      allows the user to override list options (like exit policies and
      ports to listen on) from the command line, rather than simply
      appending to the list.
    - You can get the old (appending) command-line behavior for "list"
      options by prefixing the option name with a "+".
    - You can remove all the values for a "list" option from the command
      line without adding any new ones by prefixing the option name
      with a "/".
    - Add experimental support for a "defaults" torrc file to be parsed
      before the regular torrc. Torrc options override the defaults file's
      options in the same way that the command line overrides the torrc.
      The SAVECONF controller command saves only those options which
      differ between the current configuration and the defaults file. HUP
      reloads both files. (Note: This is an experimental feature; its
      behavior will probably be refined in future 0.2.3.x-alpha versions
      to better meet packagers' needs.) Implements task 4552.

  o Minor features:
    - Try to make the introductory warning message that Tor prints on
      startup more useful for actually finding help and information.
      Resolves ticket 2474.
    - Running "make version" now displays the version of Tor that
      we're about to build. Idea from katmagic; resolves issue 4400.
    - Expire old or over-used hidden service introduction points.
      Required by fix for bug 3460.
    - Move the replay-detection cache for the RSA-encrypted parts of
      INTRODUCE2 cells to the introduction point data structures.
      Previously, we would use one replay-detection cache per hidden
      service. Required by fix for bug 3460.
    - Reduce the lifetime of elements of hidden services' Diffie-Hellman
      public key replay-detection cache from 60 minutes to 5 minutes. This
      replay-detection cache is now used only to detect multiple
      INTRODUCE2 cells specifying the same rendezvous point, so we can
      avoid launching multiple simultaneous attempts to connect to it.

  o Minor bugfixes (on Tor 0.2.2.x and earlier):
    - Resolve an integer overflow bug in smartlist_ensure_capacity().
      Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by
      Mansour Moufid.
    - Fix a minor formatting issue in one of tor-gencert's error messages.
      Fixes bug 4574.
    - Prevent a false positive from the check-spaces script, by disabling
      the "whitespace between function name and (" check for functions
      named 'op()'.
    - Fix a log message suggesting that people contact a non-existent
      email address. Fixes bug 3448.
    - Fix null-pointer access that could occur if TLS allocation failed.
      Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
    - Report a real bootstrap problem to the controller on router
      identity mismatch. Previously we just said "foo", which probably
      made a lot of sense at the time. Fixes bug 4169; bugfix on
      0.2.1.1-alpha.
    - If we had ever tried to call tor_addr_to_str() on an address of
      unknown type, we would have done a strdup() on an uninitialized
      buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha.
      Reported by "troll_un".
    - Correctly detect and handle transient lookup failures from
      tor_addr_lookup(). Fixes bug 4530; bugfix on 0.2.1.5-alpha.
      Reported by "troll_un".
    - Use tor_socket_t type for listener argument to accept(). Fixes bug
      4535; bugfix on 0.2.2.28-beta. Found by "troll_un".
    - Initialize conn->addr to a valid state in spawn_cpuworker(). Fixes
      bug 4532; found by "troll_un".

  o Minor bugfixes (on Tor 0.2.3.x):
    - Fix a compile warning in tor_inet_pton(). Bugfix on 0.2.3.8-alpha;
      fixes bug 4554.
    - Don't send two ESTABLISH_RENDEZVOUS cells when opening a new
      circuit for use as a hidden service client's rendezvous point.
      Fixes bugs 4641 and 4171; bugfix on 0.2.3.3-alpha. Diagnosed
      with help from wanoskarnet.
    - Restore behavior of overriding SocksPort, ORPort, and similar
      options from the command line. Bugfix on 0.2.3.3-alpha.

  o Build fixes:
    - Properly handle the case where the build-tree is not the same
      as the source tree when generating src/common/common_sha1.i,
      src/or/micro-revision.i, and src/or/or_sha1.i. Fixes bug 3953;
      bugfix on 0.2.0.1-alpha.

  o Code simplifications, cleanups, and refactorings:
    - Remove the pure attribute from all functions that used it
      previously. In many cases we assigned it incorrectly, because the
      functions might assert or call impure functions, and we don't have
      evidence that keeping the pure attribute is worthwhile. Implements
      changes suggested in ticket 4421.
    - Remove some dead code spotted by coverity. Fixes cid 432.
      Bugfix on 0.2.3.1-alpha, closes bug 4637.


Changes in version 0.2.3.8-alpha - 2011-11-22
  Tor 0.2.3.8-alpha fixes some crash and assert bugs, including a
  socketpair-related bug that has been bothering Windows users. It adds
  support to serve microdescriptors to controllers, so Vidalia's network
  map can resume listing relays (once Vidalia implements its side),
  and adds better support for hardware AES acceleration. Finally, it
  starts the process of adjusting the bandwidth cutoff for getting the
  "Fast" flag from 20KB to (currently) 32KB -- preliminary results show
  that tiny relays harm performance more than they help network capacity.

  o Major bugfixes:
    - Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so
      that it doesn't attempt to allocate a socketpair. This could cause
      some problems on Windows systems with overzealous firewalls. Fix for
      bug 4457; workaround for Libevent versions 2.0.1-alpha through
      2.0.15-stable.
    - Correctly sanity-check that we don't underflow on a memory
      allocation (and then assert) for hidden service introduction
      point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
      bugfix on 0.2.1.5-alpha.
    - Remove the artificially low cutoff of 20KB to guarantee the Fast
      flag. In the past few years the average relay speed has picked
      up, and while the "top 7/8 of the network get the Fast flag" and
      "all relays with 20KB or more of capacity get the Fast flag" rules
      used to have the same result, now the top 7/8 of the network has
      a capacity more like 32KB. Bugfix on 0.2.1.14-rc. Fixes bug 4489.
    - Fix a rare assertion failure when checking whether a v0 hidden
      service descriptor has any usable introduction points left, and
      we don't have enough information to build a circuit to the first
      intro point named in the descriptor. The HS client code in
      0.2.3.x no longer uses v0 HS descriptors, but this assertion can
      trigger on (and crash) v0 HS authorities. Fixes bug 4411.
      Bugfix on 0.2.3.1-alpha; diagnosed by frosty_un.
    - Make bridge authorities not crash when they are asked for their own
      descriptor. Bugfix on 0.2.3.7-alpha, reported by Lucky Green.
    - When running as a client, do not print a misleading (and plain
      wrong) log message that we're collecting "directory request"
      statistics: clients don't collect statistics. Also don't create a
      useless (because empty) stats file in the stats/ directory. Fixes
      bug 4353; bugfix on 0.2.2.34 and 0.2.3.7-alpha.

  o Major features:
    - Allow Tor controllers like Vidalia to obtain the microdescriptor
      for a relay by identity digest or nickname. Previously,
      microdescriptors were only available by their own digests, so a
      controller would have to ask for and parse the whole microdescriptor
      consensus in order to look up a single relay's microdesc. Fixes
      bug 3832; bugfix on 0.2.3.1-alpha.
    - Use OpenSSL's EVP interface for AES encryption, so that all AES
      operations can use hardware acceleration (if present). Resolves
      ticket 4442.

  o Minor bugfixes (on 0.2.2.x and earlier):
    - Detect failure to initialize Libevent. This fix provides better
      detection for future instances of bug 4457.
    - Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers
      function. This was eating up hideously large amounts of time on some
      busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
    - Don't warn about unused log_mutex in log.c when building with
      --disable-threads using a recent GCC. Fixes bug 4437; bugfix on
      0.1.0.6-rc which introduced --disable-threads.
    - Allow manual 'authenticate' commands to the controller interface
      from netcat (nc) as well as telnet. We were rejecting them because
      they didn't come with the expected whitespace at the end of the
      command. Bugfix on 0.1.1.1-alpha; fixes bug 2893.
    - Fix some (not actually triggerable) buffer size checks in usage of
      tor_inet_ntop. Fixes bug 4434; bugfix on Tor 0.2.0.1-alpha. Patch
      by Anders Sundman.
    - Fix parsing of some corner-cases with tor_inet_pton(). Fixes
      bug 4515; bugfix on 0.2.0.1-alpha; fix by Anders Sundman.
    - When configuring, starting, or stopping an NT service, stop
      immediately after the service configuration attempt has succeeded
      or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
    - When sending a NETINFO cell, include the original address
      received for the other side, not its canonical address. Found
      by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
    - Rename the bench_{aes,dmap} functions to test_*, so that tinytest
      can pick them up when the tests aren't disabled. Bugfix on
      0.2.2.4-alpha which introduced tinytest.
    - Fix a memory leak when we check whether a hidden service
      descriptor has any usable introduction points left. Fixes bug
      4424. Bugfix on 0.2.2.25-alpha.
    - Fix a memory leak in launch_direct_bridge_descriptor_fetch() that
      occurred when a client tried to fetch a descriptor for a bridge
      in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.

  o Minor bugfixes (on 0.2.3.x):
    - Make util unit tests build correctly with MSVC. Bugfix on
      0.2.3.3-alpha. Patch by Gisle Vanem.
    - Successfully detect AUTH_CHALLENGE cells with no recognized
      authentication type listed. Fixes bug 4367; bugfix on 0.2.3.6-alpha.
      Found by frosty_un.
    - If a relay receives an AUTH_CHALLENGE cell it can't answer,
      it should still send a NETINFO cell to allow the connection to
      become open. Fixes bug 4368; fix on 0.2.3.6-alpha; bug found by
      "frosty".
    - Log less loudly when we get an invalid authentication certificate
      from a source other than a directory authority: it's not unusual
      to see invalid certs because of clock skew. Fixes bug 4370; bugfix
      on 0.2.3.6-alpha.
    - Tolerate servers with more clock skew in their authentication
      certificates than previously. Fixes bug 4371; bugfix on
      0.2.3.6-alpha.
    - Fix a couple of compile warnings on Windows. Fixes bug 4469; bugfix
      on 0.2.3.4-alpha and 0.2.3.6-alpha.

  o Minor features:
    - Add two new config options for directory authorities:
      AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the
      Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold
      that is always sufficient to satisfy the bandwidth requirement for
      the Guard flag. Now it will be easier for researchers to simulate
      Tor networks with different values. Resolves ticket 4484.
    - When Tor ignores a hidden service specified in its configuration,
      include the hidden service's directory in the warning message.
      Previously, we would only tell the user that some hidden service
      was ignored. Bugfix on 0.0.6; fixes bug 4426.
    - When we fail to initialize Libevent, retry with IOCP disabled so we
      don't need to turn on multi-threading support in Libevent, which in
      turn requires a working socketpair(). This is a workaround for bug
      4457, which affects Libevent versions from 2.0.1-alpha through
      2.0.15-stable.
    - Detect when we try to build on a platform that doesn't define
      AF_UNSPEC to 0. We don't work there, so refuse to compile.
    - Update to the November 1 2011 Maxmind GeoLite Country database.

  o Packaging changes:
    - Make it easier to automate expert package builds on Windows,
      by removing an absolute path from makensis.exe command.

  o Code simplifications and refactoring:
    - Remove some redundant #include directives throughout the code.
      Patch from Andrea Gelmini.
    - Unconditionally use OpenSSL's AES implementation instead of our
      old built-in one. OpenSSL's AES has been better for a while, and
      relatively few servers should still be on any version of OpenSSL
      that doesn't have good optimized assembly AES.
    - Use the name "CERTS" consistently to refer to the new cell type;
      we were calling it CERT in some places and CERTS in others.

  o Testing:
    - Numerous new unit tests for functions in util.c and address.c by
      Anders Sundman.
    - The long-disabled benchmark tests are now split into their own
      ./src/test/bench binary.
    - The benchmark tests can now use more accurate timers than
      gettimeofday() when such timers are available.


Changes in version 0.2.3.7-alpha - 2011-10-30
  Tor 0.2.3.7-alpha fixes a crash bug in 0.2.3.6-alpha introduced by
  the new v3 handshake. It also resolves yet another bridge address
  enumeration issue.

  o Major bugfixes:
    - If we mark an OR connection for close based on a cell we process,
      don't process any further cells on it. We already avoid further
      reads on marked-for-close connections, but now we also discard the
      cells we'd already read. Fixes bug 4299; bugfix on 0.2.0.10-alpha,
      which was the first version where we might mark a connection for
      close based on processing a cell on it.
    - Fix a double-free bug that would occur when we received an invalid
      certificate in a CERT cell in the new v3 handshake. Fixes bug 4343;
      bugfix on 0.2.3.6-alpha.
    - Bridges no longer include their address in NETINFO cells on outgoing
      OR connections, to allow them to blend in better with clients.
      Removes another avenue for enumerating bridges. Reported by
      "troll_un". Fixes bug 4348; bugfix on 0.2.0.10-alpha, when NETINFO
      cells were introduced.

  o Trivial fixes:
    - Fixed a typo in a hibernation-related log message. Fixes bug 4331;
      bugfix on 0.2.2.23-alpha; found by "tmpname0901".


Changes in version 0.2.3.6-alpha - 2011-10-26
  Tor 0.2.3.6-alpha includes the fix from 0.2.2.34 for a critical
  anonymity vulnerability where an attacker can deanonymize Tor
  users. Everybody should upgrade.

  This release also features support for a new v3 connection handshake
  protocol, and fixes to make hidden service connections more robust.

  o Major features:
    - Implement a new handshake protocol (v3) for authenticating Tors to
      each other over TLS. It should be more resistant to fingerprinting
      than previous protocols, and should require less TLS hacking for
      future Tor implementations. Implements proposal 176.
    - Allow variable-length padding cells to disguise the length of
      Tor's TLS records. Implements part of proposal 184.

  o Privacy/anonymity fixes (clients):
    - Clients and bridges no longer send TLS certificate chains on
      outgoing OR connections. Previously, each client or bridge would
      use the same cert chain for all outgoing OR connections until
      its IP address changes, which allowed any relay that the client
      or bridge contacted to determine which entry guards it is using.
      Fixes CVE-2011-2768. Bugfix on 0.0.9pre5; found by "frosty_un".
    - If a relay receives a CREATE_FAST cell on a TLS connection, it
      no longer considers that connection as suitable for satisfying a
      circuit EXTEND request. Now relays can protect clients from the
      CVE-2011-2768 issue even if the clients haven't upgraded yet.
    - Directory authorities no longer assign the Guard flag to relays
      that haven't upgraded to the above "refuse EXTEND requests
      to client connections" fix. Now directory authorities can
      protect clients from the CVE-2011-2768 issue even if neither
      the clients nor the relays have upgraded yet. There's a new
      "GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays" config option
      to let us transition smoothly, else tomorrow there would be no
      guard relays.

  o Major bugfixes (hidden services):
    - Improve hidden service robustness: when an attempt to connect to
      a hidden service ends, be willing to refetch its hidden service
      descriptors from each of the HSDir relays responsible for them
      immediately. Previously, we would not consider refetching the
      service's descriptors from each HSDir for 15 minutes after the last
      fetch, which was inconvenient if the hidden service was not running
      during the first attempt. Bugfix on 0.2.0.18-alpha; fixes bug 3335.
    - When one of a hidden service's introduction points appears to be
      unreachable, stop trying it. Previously, we would keep trying
      to build circuits to the introduction point until we lost the
      descriptor, usually because the user gave up and restarted Tor.
      Partly fixes bug 3825.
    - Don't launch a useless circuit after failing to use one of a
      hidden service's introduction points. Previously, we would
      launch a new introduction circuit, but not set the hidden service
      which that circuit was intended to connect to, so it would never
      actually be used. A different piece of code would then create a
      new introduction circuit correctly. Bug reported by katmagic and
      found by Sebastian Hahn. Bugfix on 0.2.1.13-alpha; fixes bug 4212.

  o Major bugfixes (other):
    - Bridges now refuse CREATE or CREATE_FAST cells on OR connections
      that they initiated. Relays could distinguish incoming bridge
      connections from client connections, creating another avenue for
      enumerating bridges. Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha.
      Found by "frosty_un".
    - Don't update the AccountingSoftLimitHitAt state file entry whenever
      tor gets started. This prevents a wrong average bandwidth
      estimate, which would cause relays to always start a new accounting
      interval at the earliest possible moment. Fixes bug 2003; bugfix
      on 0.2.2.7-alpha. Reported by BryonEldridge, who also helped
      immensely in tracking this bug down.
    - Fix a crash bug when changing node restrictions while a DNS lookup
      is in-progress. Fixes bug 4259; bugfix on 0.2.2.25-alpha. Bugfix
      by "Tey'".

  o Minor bugfixes (on 0.2.2.x and earlier):
    - When a hidden service turns an extra service-side introduction
      circuit into a general-purpose circuit, free the rend_data and
      intro_key fields first, so we won't leak memory if the circuit
      is cannibalized for use as another service-side introduction
      circuit. Bugfix on 0.2.1.7-alpha; fixes bug 4251.
    - Rephrase the log message emitted if the TestSocks check is
      successful. Patch from Fabian Keil; fixes bug 4094.
    - Bridges now skip DNS self-tests, to act a little more stealthily.
      Fixes bug 4201; bugfix on 0.2.0.3-alpha, which first introduced
      bridges. Patch by "warms0x".
    - Remove a confusing dollar sign from the example fingerprint in the
      man page, and also make the example fingerprint a valid one. Fixes
      bug 4309; bugfix on 0.2.1.3-alpha.
    - Fix internal bug-checking logic that was supposed to catch
      failures in digest generation so that it will fail more robustly
      if we ask for a nonexistent algorithm. Found by Coverity Scan.
      Bugfix on 0.2.2.1-alpha; fixes Coverity CID 479.
    - Report any failure in init_keys() calls launched because our
      IP address has changed. Spotted by Coverity Scan. Bugfix on
      0.1.1.4-alpha; fixes CID 484.

  o Minor bugfixes (on 0.2.3.x):
    - Fix a bug in configure.in that kept it from building a configure
      script with autoconf versions earlier than 2.61. Fixes bug 2430;
      bugfix on 0.2.3.1-alpha.
    - Don't warn users that they are exposing a client port to the
      Internet if they have specified an RFC1918 address. Previously,
      we would warn if the user had specified any non-loopback
      address. Bugfix on 0.2.3.3-alpha. Fixes bug 4018; reported by Tas.
    - Fix memory leaks in the failing cases of the new SocksPort and
      ControlPort code. Found by Coverity Scan. Bugfix on 0.2.3.3-alpha;
      fixes coverity CIDs 485, 486, and 487.

  o Minor features:
    - When a hidden service's introduction point times out, consider
      trying it again during the next attempt to connect to the
      HS. Previously, we would not try it again unless a newly fetched
      descriptor contained it. Required by fixes for bugs 1297 and 3825.
    - The next version of Windows will be called Windows 8, and it has
      a major version of 6, minor version of 2. Correctly identify that
      version instead of calling it "Very recent version". Resolves
      ticket 4153; reported by funkstar.
    - The Bridge Authority now writes statistics on how many bridge
      descriptors it gave out in total, and how many unique descriptors
      it gave out. It also lists how often the most and least commonly
      fetched descriptors were given out, as well as the median and
      25th/75th percentile. Implements tickets 4200 and 4294.
    - Update to the October 4 2011 Maxmind GeoLite Country database.

  o Code simplifications and refactoring:
    - Remove some old code to remember statistics about which descriptors
      we've served as a directory mirror. The feature wasn't used and
      is outdated now that microdescriptors are around.
    - Rename Tor functions that turn strings into addresses, so that
      "parse" indicates that no hostname resolution occurs, and
      "lookup" indicates that hostname resolution may occur. This
      should help prevent mistakes in the future. Fixes bug 3512.


Changes in version 0.2.2.34 - 2011-10-26
  Tor 0.2.2.34 fixes a critical anonymity vulnerability where an attacker
  can deanonymize Tor users. Everybody should upgrade.

  The attack relies on four components: 1) Clients reuse their TLS cert
  when talking to different relays, so relays can recognize a user by
  the identity key in her cert. 2) An attacker who knows the client's
  identity key can probe each guard relay to see if that identity key
  is connected to that guard relay right now. 3) A variety of active
  attacks in the literature (starting from "Low-Cost Traffic Analysis
  of Tor" by Murdoch and Danezis in 2005) allow a malicious website to
  discover the guard relays that a Tor user visiting the website is using.
  4) Clients typically pick three guards at random, so the set of guards
  for a given user could well be a unique fingerprint for her. This
  release fixes components #1 and #2, which is enough to block the attack;
  the other two remain as open research problems. Special thanks to
  "frosty_un" for reporting the issue to us!

  Clients should upgrade so they are no longer recognizable by the TLS
  certs they present. Relays should upgrade so they no longer allow a
  remote attacker to probe them to test whether unpatched clients are
  currently connected to them.

  This release also fixes several vulnerabilities that allow an attacker
  to enumerate bridge relays. Some bridge enumeration attacks still
  remain; see for example proposal 188.

  o Privacy/anonymity fixes (clients):
    - Clients and bridges no longer send TLS certificate chains on
      outgoing OR connections. Previously, each client or bridge would
      use the same cert chain for all outgoing OR connections until
      its IP address changes, which allowed any relay that the client
      or bridge contacted to determine which entry guards it is using.
      Fixes CVE-2011-2768. Bugfix on 0.0.9pre5; found by "frosty_un".
    - If a relay receives a CREATE_FAST cell on a TLS connection, it
      no longer considers that connection as suitable for satisfying a
      circuit EXTEND request. Now relays can protect clients from the
      CVE-2011-2768 issue even if the clients haven't upgraded yet.
    - Directory authorities no longer assign the Guard flag to relays
      that haven't upgraded to the above "refuse EXTEND requests
      to client connections" fix. Now directory authorities can
      protect clients from the CVE-2011-2768 issue even if neither
      the clients nor the relays have upgraded yet. There's a new
      "GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays" config option
      to let us transition smoothly, else tomorrow there would be no
      guard relays.

  o Privacy/anonymity fixes (bridge enumeration):
    - Bridge relays now do their directory fetches inside Tor TLS
      connections, like all the other clients do, rather than connecting
      directly to the DirPort like public relays do. Removes another
      avenue for enumerating bridges. Fixes bug 4115; bugfix on 0.2.0.35.
    - Bridges relays now build circuits for themselves in a more similar
      way to how clients build them. Removes another avenue for
      enumerating bridges. Fixes bug 4124; bugfix on 0.2.0.3-alpha,
      when bridges were introduced.
    - Bridges now refuse CREATE or CREATE_FAST cells on OR connections
      that they initiated. Relays could distinguish incoming bridge
      connections from client connections, creating another avenue for
      enumerating bridges. Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha.
      Found by "frosty_un".

  o Major bugfixes:
    - Fix a crash bug when changing node restrictions while a DNS lookup
      is in-progress. Fixes bug 4259; bugfix on 0.2.2.25-alpha. Bugfix
      by "Tey'".
    - Don't launch a useless circuit after failing to use one of a
      hidden service's introduction points. Previously, we would
      launch a new introduction circuit, but not set the hidden service
      which that circuit was intended to connect to, so it would never
      actually be used. A different piece of code would then create a
      new introduction circuit correctly. Bug reported by katmagic and
      found by Sebastian Hahn. Bugfix on 0.2.1.13-alpha; fixes bug 4212.

  o Minor bugfixes:
    - Change an integer overflow check in the OpenBSD_Malloc code so
      that GCC is less likely to eliminate it as impossible. Patch
      from Mansour Moufid. Fixes bug 4059.
    - When a hidden service turns an extra service-side introduction
      circuit into a general-purpose circuit, free the rend_data and
      intro_key fields first, so we won't leak memory if the circuit
      is cannibalized for use as another service-side introduction
      circuit. Bugfix on 0.2.1.7-alpha; fixes bug 4251.
    - Bridges now skip DNS self-tests, to act a little more stealthily.
      Fixes bug 4201; bugfix on 0.2.0.3-alpha, which first introduced
      bridges. Patch by "warms0x".
    - Fix internal bug-checking logic that was supposed to catch
      failures in digest generation so that it will fail more robustly
      if we ask for a nonexistent algorithm. Found by Coverity Scan.
      Bugfix on 0.2.2.1-alpha; fixes Coverity CID 479.
    - Report any failure in init_keys() calls launched because our
      IP address has changed. Spotted by Coverity Scan. Bugfix on
      0.1.1.4-alpha; fixes CID 484.

  o Minor bugfixes (log messages and documentation):
    - Remove a confusing dollar sign from the example fingerprint in the
      man page, and also make the example fingerprint a valid one. Fixes
      bug 4309; bugfix on 0.2.1.3-alpha.
    - The next version of Windows will be called Windows 8, and it has
      a major version of 6, minor version of 2. Correctly identify that
      version instead of calling it "Very recent version". Resolves
      ticket 4153; reported by funkstar.
    - Downgrade log messages about circuit timeout calibration from
      "notice" to "info": they don't require or suggest any human
      intervention. Patch from Tom Lowenthal. Fixes bug 4063;
      bugfix on 0.2.2.14-alpha.

  o Minor features:
    - Turn on directory request statistics by default and include them in
      extra-info descriptors. Don't break if we have no GeoIP database.
      Backported from 0.2.3.1-alpha; implements ticket 3951.
    - Update to the October 4 2011 Maxmind GeoLite Country database.


Changes in version 0.2.1.31 - 2011-10-26
  Tor 0.2.1.31 backports important security and privacy fixes for
  oldstable. This release is intended only for package maintainers and
  others who cannot use the 0.2.2 stable series. All others should be
  using Tor 0.2.2.x or newer.

  o Security fixes (also included in 0.2.2.x):
    - Replace all potentially sensitive memory comparison operations
      with versions whose runtime does not depend on the data being
      compared. This will help resist a class of attacks where an
      adversary can use variations in timing information to learn
      sensitive data. Fix for one case of bug 3122. (Safe memcmp
      implementation by Robert Ransom based partially on code by DJB.)
    - Fix an assert in parsing router descriptors containing IPv6
      addresses. This one took down the directory authorities when
      somebody tried some experimental code. Bugfix on 0.2.1.3-alpha.

  o Privacy/anonymity fixes (also included in 0.2.2.x):
    - Clients and bridges no longer send TLS certificate chains on
      outgoing OR connections. Previously, each client or bridge would
      use the same cert chain for all outgoing OR connections until
      its IP address changes, which allowed any relay that the client
      or bridge contacted to determine which entry guards it is using.
      Fixes CVE-2011-2768. Bugfix on 0.0.9pre5; found by "frosty_un".
    - If a relay receives a CREATE_FAST cell on a TLS connection, it
      no longer considers that connection as suitable for satisfying a
      circuit EXTEND request. Now relays can protect clients from the
      CVE-2011-2768 issue even if the clients haven't upgraded yet.
    - Bridges now refuse CREATE or CREATE_FAST cells on OR connections
      that they initiated. Relays could distinguish incoming bridge
      connections from client connections, creating another avenue for
      enumerating bridges. Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha.
      Found by "frosty_un".
    - When receiving a hidden service descriptor, check that it is for
      the hidden service we wanted. Previously, Tor would store any
      hidden service descriptors that a directory gave it, whether it
      wanted them or not. This wouldn't have let an attacker impersonate
      a hidden service, but it did let directories pre-seed a client
      with descriptors that it didn't want. Bugfix on 0.0.6.
    - Avoid linkability based on cached hidden service descriptors: forget
      all hidden service descriptors cached as a client when processing a
      SIGNAL NEWNYM command. Fixes bug 3000; bugfix on 0.0.6.
    - Make the bridge directory authority refuse to answer directory
      requests for "all" descriptors. It used to include bridge
      descriptors in its answer, which was a major information leak.
      Found by "piebeer". Bugfix on 0.2.0.3-alpha.
    - Don't attach new streams to old rendezvous circuits after SIGNAL
      NEWNYM. Previously, we would keep using an existing rendezvous
      circuit if it remained open (i.e. if it were kept open by a
      long-lived stream, or if a new stream were attached to it before
      Tor could notice that it was old and no longer in use). Bugfix on
      0.1.1.15-rc; fixes bug 3375.

  o Minor bugfixes (also included in 0.2.2.x):
    - When we restart our relay, we might get a successful connection
      from the outside before we've started our reachability tests,
      triggering a warning: "ORPort found reachable, but I have no
      routerinfo yet. Failing to inform controller of success." This
      bug was harmless unless Tor is running under a controller
      like Vidalia, in which case the controller would never get a
      REACHABILITY_SUCCEEDED status event. Bugfix on 0.1.2.6-alpha;
      fixes bug 1172.
    - Build correctly on OSX with zlib 1.2.4 and higher with all warnings
      enabled. Fixes bug 1526.
    - Remove undocumented option "-F" from tor-resolve: it hasn't done
      anything since 0.2.1.16-rc.
    - Avoid signed/unsigned comparisons by making SIZE_T_CEILING unsigned.
      None of the cases where we did this before were wrong, but by making
      this change we avoid warnings. Fixes bug 2475; bugfix on 0.2.1.28.
    - Fix a rare crash bug that could occur when a client was configured
      with a large number of bridges. Fixes bug 2629; bugfix on
      0.2.1.2-alpha. Bugfix by trac user "shitlei".
    - Correct the warning displayed when a rendezvous descriptor exceeds
      the maximum size. Fixes bug 2750; bugfix on 0.2.1.5-alpha. Found by
      John Brooks.
    - Fix an uncommon assertion failure when running with DNSPort under
      heavy load. Fixes bug 2933; bugfix on 0.2.0.1-alpha.
    - When warning about missing zlib development packages during compile,
      give the correct package names. Bugfix on 0.2.0.1-alpha.
    - Require that introduction point keys and onion keys have public
      exponent 65537. Bugfix on 0.2.0.10-alpha.
    - Do not crash when our configuration file becomes unreadable, for
      example due to a permissions change, between when we start up
      and when a controller calls SAVECONF. Fixes bug 3135; bugfix
      on 0.0.9pre6.
    - Fix warnings from GCC 4.6's "-Wunused-but-set-variable" option.
      Fixes bug 3208.
    - Always NUL-terminate the sun_path field of a sockaddr_un before
      passing it to the kernel. (Not a security issue: kernels are
      smart enough to reject bad sockaddr_uns.) Found by Coverity;
      CID #428. Bugfix on Tor 0.2.0.3-alpha.
    - Don't stack-allocate the list of supplementary GIDs when we're
      about to log them. Stack-allocating NGROUPS_MAX gid_t elements
      could take up to 256K, which is way too much stack. Found by
      Coverity; CID #450. Bugfix on 0.2.1.7-alpha.

  o Minor bugfixes (only in 0.2.1.x):
    - Resume using micro-version numbers in 0.2.1.x: our Debian packages
      rely on them. Bugfix on 0.2.1.30.
    - Use git revisions instead of svn revisions when generating our
      micro-version numbers. Bugfix on 0.2.1.15-rc; fixes bug 2402.

  o Minor features (also included in 0.2.2.x):
    - Adjust the expiration time on our SSL session certificates to
      better match SSL certs seen in the wild. Resolves ticket 4014.
    - Allow nameservers with IPv6 address. Resolves bug 2574.
    - Update to the October 4 2011 Maxmind GeoLite Country database.


Changes in version 0.2.3.5-alpha - 2011-09-28
  Tor 0.2.3.5-alpha fixes two bugs that make it possible to enumerate
  bridge relays; fixes an assertion error that many users started hitting
  today; and adds the ability to refill token buckets more often than
  once per second, allowing significant performance improvements.

  o Security fixes:
    - Bridge relays now do their directory fetches inside Tor TLS
      connections, like all the other clients do, rather than connecting
      directly to the DirPort like public relays do. Removes another
      avenue for enumerating bridges. Fixes bug 4115; bugfix on 0.2.0.35.
    - Bridges relays now build circuits for themselves in a more similar
      way to how clients build them. Removes another avenue for
      enumerating bridges. Fixes bug 4124; bugfix on 0.2.0.3-alpha,
      when bridges were introduced.

  o Major bugfixes:
    - Fix an "Assertion md->held_by_node == 1 failed" error that could
      occur when the same microdescriptor was referenced by two node_t
      objects at once. Fix for bug 4118; bugfix on Tor 0.2.3.1-alpha.

  o Major features (networking):
    - Add a new TokenBucketRefillInterval option to refill token buckets
      more frequently than once per second. This should improve network
      performance, alleviate queueing problems, and make traffic less
      bursty. Implements proposal 183; closes ticket 3630. Design by
      Florian Tschorsch and Björn Scheuermann; implementation by
      Florian Tschorsch.

  o Minor bugfixes:
    - Change an integer overflow check in the OpenBSD_Malloc code so
      that GCC is less likely to eliminate it as impossible. Patch
      from Mansour Moufid. Fixes bug 4059.

  o Minor bugfixes (usability):
    - Downgrade log messages about circuit timeout calibration from
      "notice" to "info": they don't require or suggest any human
      intervention. Patch from Tom Lowenthal. Fixes bug 4063;
      bugfix on 0.2.2.14-alpha.

  o Minor features (diagnostics):
    - When the system call to create a listener socket fails, log the
      error message explaining why. This may help diagnose bug 4027.


Changes in version 0.2.3.4-alpha - 2011-09-13
  Tor 0.2.3.4-alpha includes the fixes from 0.2.2.33, including a slight
  tweak to Tor's TLS handshake that makes relays and bridges that run
  this new version reachable from Iran again. It also fixes a few new
  bugs in 0.2.3.x, and teaches relays to recognize when they're not
  listed in the network consensus and republish.

  o Major bugfixes (also part of 0.2.2.33):
    - Avoid an assertion failure when reloading a configuration with
      TrackExitHosts changes. Found and fixed by 'laruldan'. Fixes bug
      3923; bugfix on 0.2.2.25-alpha.

  o Minor features (security, also part of 0.2.2.33):
    - Check for replays of the public-key encrypted portion of an
      INTRODUCE1 cell, in addition to the current check for replays of
      the g^x value. This prevents a possible class of active attacks
      by an attacker who controls both an introduction point and a
      rendezvous point, and who uses the malleability of AES-CTR to
      alter the encrypted g^x portion of the INTRODUCE1 cell. We think
      that these attacks are infeasible (requiring the attacker to send
      on the order of zettabytes of altered cells in a short interval),
      but we'd rather block them off in case there are any classes of
      this attack that we missed. Reported by Willem Pinckaers.

  o Minor features (also part of 0.2.2.33):
    - Adjust the expiration time on our SSL session certificates to
      better match SSL certs seen in the wild. Resolves ticket 4014.
    - Change the default required uptime for a relay to be accepted as
      a HSDir (hidden service directory) from 24 hours to 25 hours.
      Improves on 0.2.0.10-alpha; resolves ticket 2649.
    - Add a VoteOnHidServDirectoriesV2 config option to allow directory
      authorities to abstain from voting on assignment of the HSDir
      consensus flag. Related to bug 2649.
    - Update to the September 6 2011 Maxmind GeoLite Country database.

  o Minor bugfixes (also part of 0.2.2.33):
    - Demote the 'replay detected' log message emitted when a hidden
      service receives the same Diffie-Hellman public key in two different
      INTRODUCE2 cells to info level. A normal Tor client can cause that
      log message during its normal operation. Bugfix on 0.2.1.6-alpha;
      fixes part of bug 2442.
    - Demote the 'INTRODUCE2 cell is too {old,new}' log message to info
      level. There is nothing that a hidden service's operator can do
      to fix its clients' clocks. Bugfix on 0.2.1.6-alpha; fixes part
      of bug 2442.
    - Clarify a log message specifying the characters permitted in
      HiddenServiceAuthorizeClient client names. Previously, the log
      message said that "[A-Za-z0-9+-_]" were permitted; that could have
      given the impression that every ASCII character between "+" and "_"
      was permitted. Now we say "[A-Za-z0-9+_-]". Bugfix on 0.2.1.5-alpha.

  o Build fixes (also part of 0.2.2.33):
    - Clean up some code issues that prevented Tor from building on older
      BSDs. Fixes bug 3894; reported by "grarpamp".
    - Search for a platform-specific version of "ar" when cross-compiling.
      Should fix builds on iOS. Resolves bug 3909, found by Marco Bonetti.

  o Major bugfixes:
    - Fix a bug where the SocksPort option (for example) would get
      ignored and replaced by the default if a SocksListenAddress
      option was set. Bugfix on 0.2.3.3-alpha; fixes bug 3936. Fix by
      Fabian Keil.

  o Major features:
    - Relays now try regenerating and uploading their descriptor more
      frequently if they are not listed in the consensus, or if the
      version of their descriptor listed in the consensus is too
      old. This fix should prevent situations where a server declines
      to re-publish itself because it has done so too recently, even
      though the authorities decided not to list its recent-enough
      descriptor. Fix for bug 3327.

  o Minor features:
    - Relays now include a reason for regenerating their descriptors
      in an HTTP header when uploading to the authorities. This will
      make it easier to debug descriptor-upload issues in the future.
    - When starting as root and then changing our UID via the User
      control option, and we have a ControlSocket configured, make sure
      that the ControlSocket is owned by the same account that Tor will
      run under. Implements ticket 3421; fix by Jérémy Bobbio.

  o Minor bugfixes:
    - Abort if tor_vasprintf fails in connection_printf_to_buf (a
      utility function used in the control-port code). This shouldn't
      ever happen unless Tor is completely out of memory, but if it did
      happen and Tor somehow recovered from it, Tor could have sent a log
      message to a control port in the middle of a reply to a controller
      command. Fixes part of bug 3428; bugfix on 0.1.2.3-alpha.
    - Make 'FetchUselessDescriptors' cause all descriptor types and
      all consensus types (including microdescriptors) to get fetched.
      Fixes bug 3851; bugfix on 0.2.3.1-alpha.

  o Code refactoring:
    - Make a new "entry connection" struct as an internal subtype of "edge
      connection", to simplify the code and make exit connections smaller.


Changes in version 0.2.2.33 - 2011-09-13
  Tor 0.2.2.33 fixes several bugs, and includes a slight tweak to Tor's
  TLS handshake that makes relays and bridges that run this new version
  reachable from Iran again.

  o Major bugfixes:
    - Avoid an assertion failure when reloading a configuration with
      TrackExitHosts changes. Found and fixed by 'laruldan'. Fixes bug
      3923; bugfix on 0.2.2.25-alpha.

  o Minor features (security):
    - Check for replays of the public-key encrypted portion of an
      INTRODUCE1 cell, in addition to the current check for replays of
      the g^x value. This prevents a possible class of active attacks
      by an attacker who controls both an introduction point and a
      rendezvous point, and who uses the malleability of AES-CTR to
      alter the encrypted g^x portion of the INTRODUCE1 cell. We think
      that these attacks are infeasible (requiring the attacker to send
      on the order of zettabytes of altered cells in a short interval),
      but we'd rather block them off in case there are any classes of
      this attack that we missed. Reported by Willem Pinckaers.

  o Minor features:
    - Adjust the expiration time on our SSL session certificates to
      better match SSL certs seen in the wild. Resolves ticket 4014.
    - Change the default required uptime for a relay to be accepted as
      a HSDir (hidden service directory) from 24 hours to 25 hours.
      Improves on 0.2.0.10-alpha; resolves ticket 2649.
    - Add a VoteOnHidServDirectoriesV2 config option to allow directory
      authorities to abstain from voting on assignment of the HSDir
      consensus flag. Related to bug 2649.
    - Update to the September 6 2011 Maxmind GeoLite Country database.

  o Minor bugfixes (documentation and log messages):
    - Correct the man page to explain that HashedControlPassword and
      CookieAuthentication can both be set, in which case either method
      is sufficient to authenticate to Tor. Bugfix on 0.2.0.7-alpha,
      when we decided to allow these config options to both be set. Issue
      raised by bug 3898.
    - Demote the 'replay detected' log message emitted when a hidden
      service receives the same Diffie-Hellman public key in two different
      INTRODUCE2 cells to info level. A normal Tor client can cause that
      log message during its normal operation. Bugfix on 0.2.1.6-alpha;
      fixes part of bug 2442.
    - Demote the 'INTRODUCE2 cell is too {old,new}' log message to info
      level. There is nothing that a hidden service's operator can do
      to fix its clients' clocks. Bugfix on 0.2.1.6-alpha; fixes part
      of bug 2442.
    - Clarify a log message specifying the characters permitted in
      HiddenServiceAuthorizeClient client names. Previously, the log
      message said that "[A-Za-z0-9+-_]" were permitted; that could have
      given the impression that every ASCII character between "+" and "_"
      was permitted. Now we say "[A-Za-z0-9+_-]". Bugfix on 0.2.1.5-alpha.

  o Build fixes:
    - Provide a substitute implementation of lround() for MSVC, which
      apparently lacks it. Patch from Gisle Vanem.
    - Clean up some code issues that prevented Tor from building on older
      BSDs. Fixes bug 3894; reported by "grarpamp".
    - Search for a platform-specific version of "ar" when cross-compiling.
      Should fix builds on iOS. Resolves bug 3909, found by Marco Bonetti.


Changes in version 0.2.3.3-alpha - 2011-09-01
  Tor 0.2.3.3-alpha adds a new "stream isolation" feature to improve Tor's
  security, and provides client-side support for the microdescriptor
  and optimistic data features introduced earlier in the 0.2.3.x
  series. It also includes numerous critical bugfixes in the (optional)
  bufferevent-based networking backend.

  o Major features (stream isolation):
    - You can now configure Tor so that streams from different
      applications are isolated on different circuits, to prevent an
      attacker who sees your streams as they leave an exit node from
      linking your sessions to one another. To do this, choose some way
      to distinguish the applications: have them connect to different
      SocksPorts, or have one of them use SOCKS4 while the other uses
      SOCKS5, or have them pass different authentication strings to the
      SOCKS proxy. Then, use the new SocksPort syntax to configure the
      degree of isolation you need. This implements Proposal 171.
    - There's a new syntax for specifying multiple client ports (such as
      SOCKSPort, TransPort, DNSPort, NATDPort): you can now just declare
      multiple *Port entries with full addr:port syntax on each.
      The old *ListenAddress format is still supported, but you can't
      mix it with the new *Port syntax.

  o Major features (other):
    - Enable microdescriptor fetching by default for clients. This allows
      clients to download a much smaller amount of directory information.
      To disable it (and go back to the old-style consensus and
      descriptors), set "UseMicrodescriptors 0" in your torrc file.
    - Tor's firewall-helper feature, introduced in 0.2.3.1-alpha (see the
      "PortForwarding" config option), now supports Windows.
    - When using an exit relay running 0.2.3.x, clients can now
      "optimistically" send data before the exit relay reports that
      the stream has opened. This saves a round trip when starting
      connections where the client speaks first (such as web browsing).
      This behavior is controlled by a consensus parameter (currently
      disabled). To turn it on or off manually, use the "OptimisticData"
      torrc option. Implements proposal 181; code by Ian Goldberg.

  o Major bugfixes (bufferevents, fixes on 0.2.3.1-alpha):
    - When using IOCP on Windows, we need to enable Libevent windows
      threading support.
    - The IOCP backend now works even when the user has not specified
      the (internal, debugging-only) _UseFilteringSSLBufferevents option.
      Fixes part of bug 3752.
    - Correctly record the bytes we've read and written when using
      bufferevents, so that we can include them in our bandwidth history
      and advertised bandwidth. Fixes bug 3803.
    - Apply rate-limiting only at the bottom of a chain of filtering
      bufferevents. This prevents us from filling up internal read
      buffers and violating rate-limits when filtering bufferevents
      are enabled. Fixes part of bug 3804.
    - Add high-watermarks to the output buffers for filtered
      bufferevents. This prevents us from filling up internal write
      buffers and wasting CPU cycles when filtering bufferevents are
      enabled. Fixes part of bug 3804.
    - Correctly notice when data has been written from a bufferevent
      without flushing it completely. Fixes bug 3805.
    - Fix a bug where server-side tunneled bufferevent-based directory
      streams would get closed prematurely. Fixes bug 3814.
    - Fix a use-after-free error with per-connection rate-limiting
      buckets. Fixes bug 3888.

  o Major bugfixes (also part of 0.2.2.31-rc):
    - If we're configured to write our ControlPorts to disk, only write
      them after switching UID and creating the data directory. This way,
      we don't fail when starting up with a nonexistent DataDirectory
      and a ControlPortWriteToFile setting based on that directory. Fixes
      bug 3747; bugfix on Tor 0.2.2.26-beta.

  o Minor features:
    - Added a new CONF_CHANGED event so that controllers can be notified
      of any configuration changes made by other controllers, or by the
      user. Implements ticket 1692.
    - Use evbuffer_copyout() in inspect_evbuffer(). This fixes a memory
      leak when using bufferevents, and lets Libevent worry about how to
      best copy data out of a buffer.
    - Replace files in stats/ rather than appending to them. Now that we
      include statistics in extra-info descriptors, it makes no sense to
      keep old statistics forever. Implements ticket 2930.

  o Minor features (build compatibility):
    - Limited, experimental support for building with nmake and MSVC.
    - Provide a substitute implementation of lround() for MSVC, which
      apparently lacks it. Patch from Gisle Vanem.

  o Minor features (also part of 0.2.2.31-rc):
    - Update to the August 2 2011 Maxmind GeoLite Country database.

  o Minor bugfixes (on 0.2.3.x-alpha):
    - Fix a spurious warning when parsing SOCKS requests with
      bufferevents enabled. Fixes bug 3615; bugfix on 0.2.3.2-alpha.
    - Get rid of a harmless warning that could happen on relays running
      with bufferevents. The warning was caused by someone doing an http
      request to a relay's orport. Also don't warn for a few related
      non-errors. Fixes bug 3700; bugfix on 0.2.3.1-alpha.

  o Minor bugfixes (on 2.2.x and earlier):
    - Correct the man page to explain that HashedControlPassword and
      CookieAuthentication can both be set, in which case either method
      is sufficient to authenticate to Tor. Bugfix on 0.2.0.7-alpha,
      when we decided to allow these config options to both be set. Issue
      raised by bug 3898.
    - The "--quiet" and "--hush" options now apply not only to Tor's
      behavior before logs are configured, but also to Tor's behavior in
      the absense of configured logs. Fixes bug 3550; bugfix on
      0.2.0.10-alpha.

  o Minor bugfixes (also part of 0.2.2.31-rc):
    - Write several files in text mode, on OSes that distinguish text
      mode from binary mode (namely, Windows). These files are:
      'buffer-stats', 'dirreq-stats', and 'entry-stats' on relays
      that collect those statistics; 'client_keys' and 'hostname' for
      hidden services that use authentication; and (in the tor-gencert
      utility) newly generated identity and signing keys. Previously,
      we wouldn't specify text mode or binary mode, leading to an
      assertion failure. Fixes bug 3607. Bugfix on 0.2.1.1-alpha (when
      the DirRecordUsageByCountry option which would have triggered
      the assertion failure was added), although this assertion failure
      would have occurred in tor-gencert on Windows in 0.2.0.1-alpha.
    - Selectively disable deprecation warnings on OS X because Lion
      started deprecating the shipped copy of openssl. Fixes bug 3643.
    - Remove an extra pair of quotation marks around the error
      message in control-port STATUS_GENERAL BUG events. Bugfix on
      0.1.2.6-alpha; fixes bug 3732.
    - When unable to format an address as a string, report its value
      as "???" rather than reusing the last formatted address. Bugfix
      on 0.2.1.5-alpha.

  o Code simplifications and refactoring:
    - Rewrite the listener-selection logic so that parsing which ports
      we want to listen on is now separate from binding to the ports
      we want.

  o Build changes:
    - Building Tor with bufferevent support now requires Libevent
      2.0.13-stable or later. Previous versions of Libevent had bugs in
      SSL-related bufferevents and related issues that would make Tor
      work badly with bufferevents. Requiring 2.0.13-stable also allows
      Tor with bufferevents to take advantage of Libevent APIs
      introduced after 2.0.8-rc.


Changes in version 0.2.2.32 - 2011-08-27
  The Tor 0.2.2 release series is dedicated to the memory of Andreas
  Pfitzmann (1958-2010), a pioneer in anonymity and privacy research,
  a founder of the PETS community, a leader in our field, a mentor,
  and a friend. He left us with these words: "I had the possibility
  to contribute to this world that is not as it should be. I hope I
  could help in some areas to make the world a better place, and that
  I could also encourage other people to be engaged in improving the
  world. Please, stay engaged. This world needs you, your love, your
  initiative -- now I cannot be part of that anymore."

  Tor 0.2.2.32, the first stable release in the 0.2.2 branch, is finally
  ready. More than two years in the making, this release features improved
  client performance and hidden service reliability, better compatibility
  for Android, correct behavior for bridges that listen on more than
  one address, more extensible and flexible directory object handling,
  better reporting of network statistics, improved code security, and
  many many other features and bugfixes.


Changes in version 0.2.2.31-rc - 2011-08-17
  Tor 0.2.2.31-rc is the second and hopefully final release candidate
  for the Tor 0.2.2.x series.

  o Major bugfixes:
    - Remove an extra pair of quotation marks around the error
      message in control-port STATUS_GENERAL BUG events. Bugfix on
      0.1.2.6-alpha; fixes bug 3732.
    - If we're configured to write our ControlPorts to disk, only write
      them after switching UID and creating the data directory. This way,
      we don't fail when starting up with a nonexistent DataDirectory
      and a ControlPortWriteToFile setting based on that directory. Fixes
      bug 3747; bugfix on Tor 0.2.2.26-beta.

  o Minor features:
    - Update to the August 2 2011 Maxmind GeoLite Country database.

  o Minor bugfixes:
    - Allow GETINFO fingerprint to return a fingerprint even when
      we have not yet built a router descriptor. Fixes bug 3577;
      bugfix on 0.2.0.1-alpha.
    - Write several files in text mode, on OSes that distinguish text
      mode from binary mode (namely, Windows). These files are:
      'buffer-stats', 'dirreq-stats', and 'entry-stats' on relays
      that collect those statistics; 'client_keys' and 'hostname' for
      hidden services that use authentication; and (in the tor-gencert
      utility) newly generated identity and signing keys. Previously,
      we wouldn't specify text mode or binary mode, leading to an
      assertion failure. Fixes bug 3607. Bugfix on 0.2.1.1-alpha (when
      the DirRecordUsageByCountry option which would have triggered
      the assertion failure was added), although this assertion failure
      would have occurred in tor-gencert on Windows in 0.2.0.1-alpha.
    - Selectively disable deprecation warnings on OS X because Lion
      started deprecating the shipped copy of openssl. Fixes bug 3643.
    - When unable to format an address as a string, report its value
      as "???" rather than reusing the last formatted address. Bugfix
      on 0.2.1.5-alpha.


Changes in version 0.2.3.2-alpha - 2011-07-18
  Tor 0.2.3.2-alpha introduces two new experimental features:
  microdescriptors and pluggable transports. It also continues cleaning
  up a variety of recently introduced features.

  o Major features:
    - Clients can now use microdescriptors instead of regular descriptors
      to build circuits. Microdescriptors are authority-generated
      summaries of regular descriptors' contents, designed to change
      very rarely (see proposal 158 for details). This feature is
      designed to save bandwidth, especially for clients on slow internet
      connections. It's off by default for now, since nearly no caches
      support it, but it will be on-by-default for clients in a future
      version. You can use the UseMicrodescriptors option to turn it on.
    - Tor clients using bridges can now be configured to use a separate
      'transport' proxy for each bridge. This approach helps to resist
      censorship by allowing bridges to use protocol obfuscation
      plugins. It implements part of proposal 180. Implements ticket 2841.
    - While we're trying to bootstrap, record how many TLS connections
      fail in each state, and report which states saw the most failures
      in response to any bootstrap failures. This feature may speed up
      diagnosis of censorship events. Implements ticket 3116.

  o Major bugfixes (on 0.2.3.1-alpha):
    - When configuring a large set of nodes in EntryNodes (as with
      'EntryNodes {cc}' or 'EntryNodes 1.1.1.1/16'), choose only a
      random subset to be guards, and choose them in random
      order. Fixes bug 2798.
    - Tor could crash when remembering a consensus in a non-used consensus
      flavor without having a current consensus set. Fixes bug 3361.
    - Comparing an unknown address to a microdescriptor's shortened exit
      policy would always give a "rejected" result. Fixes bug 3599.
    - Using microdescriptors as a client no longer prevents Tor from
      uploading and downloading hidden service descriptors. Fixes
      bug 3601.

  o Minor features:
    - Allow nameservers with IPv6 address. Resolves bug 2574.
    - Accept attempts to include a password authenticator in the
      handshake, as supported by SOCKS5. This handles SOCKS clients that
      don't know how to omit a password when authenticating. Resolves
      bug 1666.
    - When configuring a large set of nodes in EntryNodes, and there are
      enough of them listed as Guard so that we don't need to consider
      the non-guard entries, prefer the ones listed with the Guard flag.
    - Check for and recover from inconsistency in the microdescriptor
      cache. This will make it harder for us to accidentally free a
      microdescriptor without removing it from the appropriate data
      structures. Fixes issue 3135; issue noted by "wanoskarnet".
    - Log SSL state transitions at log level DEBUG, log domain
      HANDSHAKE. This can be useful for debugging censorship events.
      Implements ticket 3264.
    - Add port 6523 (Gobby) to LongLivedPorts. Patch by intrigeri;
      implements ticket 3439.

  o Minor bugfixes (on 0.2.3.1-alpha):
    - Do not free all general-purpose regular descriptors just
      because microdescriptor use is enabled. Fixes bug 3113.
    - Correctly link libevent_openssl when --enable-static-libevent
      is passed to configure. Fixes bug 3118.
    - Bridges should not complain during their heartbeat log messages that
      they are unlisted in the consensus: that's more or less the point
      of being a bridge. Fixes bug 3183.
    - Report a SIGNAL event to controllers when acting on a delayed
      SIGNAL NEWNYM command. Previously, we would report a SIGNAL
      event to the controller if we acted on a SIGNAL NEWNYM command
      immediately, and otherwise not report a SIGNAL event for the
      command at all. Fixes bug 3349.
    - Fix a crash when handling the SIGNAL controller command or
      reporting ERR-level status events with bufferevents enabled. Found
      by Robert Ransom. Fixes bug 3367.
    - Always ship the tor-fw-helper manpage in our release tarballs.
      Fixes bug 3389. Reported by Stephen Walker.
    - Fix a class of double-mark-for-close bugs when bufferevents
      are enabled. Fixes bug 3403.
    - Update tor-fw-helper to support libnatpmp-20110618. Fixes bug 3434.
    - Add SIGNAL to the list returned by the 'GETINFO events/names'
      control-port command. Fixes part of bug 3465.
    - Prevent using negative indices during unit test runs when read_all()
      fails. Spotted by coverity.
    - Fix a rare memory leak when checking the nodelist without it being
      present. Found by coverity.
    - Only try to download a microdescriptor-flavored consensus from
      a directory cache that provides them.

  o Minor bugfixes (on 0.2.2.x and earlier):
    - Assert that hidden-service-related operations are not performed
      using single-hop circuits. Previously, Tor would assert that
      client-side streams are not attached to single-hop circuits,
      but not that other sensitive operations on the client and service
      side are not performed using single-hop circuits. Fixes bug 3332;
      bugfix on 0.0.6.
    - Don't publish a new relay descriptor when we reload our onion key,
      unless the onion key has actually changed. Fixes bug 3263 and
      resolves another cause of bug 1810. Bugfix on 0.1.1.11-alpha.
    - Allow GETINFO fingerprint to return a fingerprint even when
      we have not yet built a router descriptor. Fixes bug 3577;
      bugfix on 0.2.0.1-alpha.
    - Make 'tor --digests' list hashes of all Tor source files. Bugfix
      on 0.2.2.4-alpha; fixes bug 3427.

  o Code simplification and refactoring:
    - Use tor_sscanf() in place of scanf() in more places through the
      code. This makes us a little more locale-independent, and
      should help shut up code-analysis tools that can't tell
      a safe sscanf string from a dangerous one.
    - Use tt_assert(), not tor_assert(), for checking for test failures.
      This makes the unit tests more able to go on in the event that
      one of them fails.
    - Split connection_about_to_close() into separate functions for each
      connection type.

  o Build changes:
    - On Windows, we now define the _WIN32_WINNT macros only if they
      are not already defined. This lets the person building Tor decide,
      if they want, to require a later version of Windows.


Changes in version 0.2.2.30-rc - 2011-07-07
  Tor 0.2.2.30-rc is the first release candidate for the Tor 0.2.2.x
  series. It fixes a few smaller bugs, but generally appears stable.
  Please test it and let us know whether it is!

  o Minor bugfixes:
    - Send a SUCCEEDED stream event to the controller when a reverse
      resolve succeeded. Fixes bug 3536; bugfix on 0.0.8pre1. Issue
      discovered by katmagic.
    - Always NUL-terminate the sun_path field of a sockaddr_un before
      passing it to the kernel. (Not a security issue: kernels are
      smart enough to reject bad sockaddr_uns.) Found by Coverity;
      CID #428. Bugfix on Tor 0.2.0.3-alpha.
    - Don't stack-allocate the list of supplementary GIDs when we're
      about to log them. Stack-allocating NGROUPS_MAX gid_t elements
      could take up to 256K, which is way too much stack. Found by
      Coverity; CID #450. Bugfix on 0.2.1.7-alpha.
    - Add BUILDTIMEOUT_SET to the list returned by the 'GETINFO
      events/names' control-port command. Bugfix on 0.2.2.9-alpha;
      fixes part of bug 3465.
    - Fix a memory leak when receiving a descriptor for a hidden
      service we didn't ask for. Found by Coverity; CID #30. Bugfix
      on 0.2.2.26-beta.

  o Minor features:
    - Update to the July 1 2011 Maxmind GeoLite Country database.


Changes in version 0.2.2.29-beta - 2011-06-20
  Tor 0.2.2.29-beta reverts an accidental behavior change for users who
  have bridge lines in their torrc but don't want to use them; gets
  us closer to having the control socket feature working on Debian;
  and fixes a variety of smaller bugs.

  o Major bugfixes:
    - Revert the UseBridges option to its behavior before 0.2.2.28-beta.
      When we changed the default behavior to "use bridges if any
      are listed in the torrc", we surprised users who had bridges
      in their torrc files but who didn't actually want to use them.
      Partial resolution for bug 3354.

  o Privacy fixes:
    - Don't attach new streams to old rendezvous circuits after SIGNAL
      NEWNYM. Previously, we would keep using an existing rendezvous
      circuit if it remained open (i.e. if it were kept open by a
      long-lived stream, or if a new stream were attached to it before
      Tor could notice that it was old and no longer in use). Bugfix on
      0.1.1.15-rc; fixes bug 3375.

  o Minor bugfixes:
    - Fix a bug when using ControlSocketsGroupWritable with User. The
      directory's group would be checked against the current group, not
      the configured group. Patch by Jérémy Bobbio. Fixes bug 3393;
      bugfix on 0.2.2.26-beta.
    - Make connection_printf_to_buf()'s behavior sane. Its callers
      expect it to emit a CRLF iff the format string ends with CRLF;
      it actually emitted a CRLF iff (a) the format string ended with
      CRLF or (b) the resulting string was over 1023 characters long or
      (c) the format string did not end with CRLF *and* the resulting
      string was 1021 characters long or longer. Bugfix on 0.1.1.9-alpha;
      fixes part of bug 3407.
    - Make send_control_event_impl()'s behavior sane. Its callers
      expect it to always emit a CRLF at the end of the string; it
      might have emitted extra control characters as well. Bugfix on
      0.1.1.9-alpha; fixes another part of bug 3407.
    - Make crypto_rand_int() check the value of its input correctly.
      Previously, it accepted values up to UINT_MAX, but could return a
      negative number if given a value above INT_MAX+1. Found by George
      Kadianakis. Fixes bug 3306; bugfix on 0.2.2pre14.
    - Avoid a segfault when reading a malformed circuit build state
      with more than INT_MAX entries. Found by wanoskarnet. Bugfix on
      0.2.2.4-alpha.
    - When asked about a DNS record type we don't support via a
      client DNSPort, reply with NOTIMPL rather than an empty
      reply. Patch by intrigeri. Fixes bug 3369; bugfix on 2.0.1-alpha.
    - Fix a rare memory leak during stats writing. Found by coverity.

  o Minor features:
    - Update to the June 1 2011 Maxmind GeoLite Country database.

  o Code simplifications and refactoring:
    - Remove some dead code as indicated by coverity.
    - Remove a few dead assignments during router parsing. Found by
      coverity.
    - Add some forgotten return value checks during unit tests. Found
      by coverity.
    - Don't use 1-bit wide signed bit fields. Found by coverity.


Changes in version 0.2.2.28-beta - 2011-06-04
  Tor 0.2.2.28-beta makes great progress towards a new stable release: we
  fixed a big bug in whether relays stay in the consensus consistently,
  we moved closer to handling bridges and hidden services correctly,
  and we started the process of better handling the dreaded "my Vidalia
  died, and now my Tor demands a password when I try to reconnect to it"
  usability issue.

  o Major bugfixes:
    - Don't decide to make a new descriptor when receiving a HUP signal.
      This bug has caused a lot of 0.2.2.x relays to disappear from the
      consensus periodically. Fixes the most common case of triggering
      bug 1810; bugfix on 0.2.2.7-alpha.
    - Actually allow nameservers with IPv6 addresses. Fixes bug 2574.
    - Don't try to build descriptors if "ORPort auto" is set and we
      don't know our actual ORPort yet. Fix for bug 3216; bugfix on
      0.2.2.26-beta.
    - Resolve a crash that occurred when setting BridgeRelay to 1 with
      accounting enabled. Fixes bug 3228; bugfix on 0.2.2.18-alpha.
    - Apply circuit timeouts to opened hidden-service-related circuits
      based on the correct start time. Previously, we would apply the
      circuit build timeout based on time since the circuit's creation;
      it was supposed to be applied based on time since the circuit
      entered its current state. Bugfix on 0.0.6; fixes part of bug 1297.
    - Use the same circuit timeout for client-side introduction
      circuits as for other four-hop circuits, rather than the timeout
      for single-hop directory-fetch circuits; the shorter timeout may
      have been appropriate with the static circuit build timeout in
      0.2.1.x and earlier, but caused many hidden service access attempts
      to fail with the adaptive CBT introduced in 0.2.2.2-alpha. Bugfix
      on 0.2.2.2-alpha; fixes another part of bug 1297.
    - In ticket 2511 we fixed a case where you could use an unconfigured
      bridge if you had configured it as a bridge the last time you ran
      Tor. Now fix another edge case: if you had configured it as a bridge
      but then switched to a different bridge via the controller, you
      would still be willing to use the old one. Bugfix on 0.2.0.1-alpha;
      fixes bug 3321.

  o Major features:
    - Add an __OwningControllerProcess configuration option and a
      TAKEOWNERSHIP control-port command. Now a Tor controller can ensure
      that when it exits, Tor will shut down. Implements feature 3049.
    - If "UseBridges 1" is set and no bridges are configured, Tor will
      now refuse to build any circuits until some bridges are set.
      If "UseBridges auto" is set, Tor will use bridges if they are
      configured and we are not running as a server, but otherwise will
      make circuits as usual. The new default is "auto". Patch by anonym,
      so the Tails LiveCD can stop automatically revealing you as a Tor
      user on startup.

  o Minor bugfixes:
    - Fix warnings from GCC 4.6's "-Wunused-but-set-variable" option.
    - Remove a trailing asterisk from "exit-policy/default" in the
      output of the control port command "GETINFO info/names". Bugfix
      on 0.1.2.5-alpha.
    - Use a wide type to hold sockets when built for 64-bit Windows builds.
      Fixes bug 3270.
    - Warn when the user configures two HiddenServiceDir lines that point
      to the same directory. Bugfix on 0.0.6 (the version introducing
      HiddenServiceDir); fixes bug 3289.
    - Remove dead code from rend_cache_lookup_v2_desc_as_dir. Fixes
      part of bug 2748; bugfix on 0.2.0.10-alpha.
    - Log malformed requests for rendezvous descriptors as protocol
      warnings, not warnings. Also, use a more informative log message
      in case someone sees it at log level warning without prior
      info-level messages. Fixes the other part of bug 2748; bugfix
      on 0.2.0.10-alpha.
    - Clear the table recording the time of the last request for each
      hidden service descriptor from each HS directory on SIGNAL NEWNYM.
      Previously, we would clear our HS descriptor cache on SIGNAL
      NEWNYM, but if we had previously retrieved a descriptor (or tried
      to) from every directory responsible for it, we would refuse to
      fetch it again for up to 15 minutes. Bugfix on 0.2.2.25-alpha;
      fixes bug 3309.
    - Fix a log message that said "bits" while displaying a value in
      bytes. Found by wanoskarnet. Fixes bug 3318; bugfix on
      0.2.0.1-alpha.
    - When checking for 1024-bit keys, check for 1024 bits, not 128
      bytes. This allows Tor to correctly discard keys of length 1017
      through 1023. Bugfix on 0.0.9pre5.

  o Minor features:
    - Relays now log the reason for publishing a new relay descriptor,
      so we have a better chance of hunting down instances of bug 1810.
      Resolves ticket 3252.
    - Revise most log messages that refer to nodes by nickname to
      instead use the "$key=nickname at address" format. This should be
      more useful, especially since nicknames are less and less likely
      to be unique. Resolves ticket 3045.
    - Log (at info level) when purging pieces of hidden-service-client
      state because of SIGNAL NEWNYM.

  o Removed options:
    - Remove undocumented option "-F" from tor-resolve: it hasn't done
      anything since 0.2.1.16-rc.


Changes in version 0.2.2.27-beta - 2011-05-18
  Tor 0.2.2.27-beta fixes a bridge-related stability bug in the previous
  release, and also adds a few more general bugfixes.

  o Major bugfixes:
    - Fix a crash bug when changing bridges in a running Tor process.
      Fixes bug 3213; bugfix on 0.2.2.26-beta.
    - When the controller configures a new bridge, don't wait 10 to 60
      seconds before trying to fetch its descriptor. Bugfix on
      0.2.0.3-alpha; fixes bug 3198 (suggested by 2355).

  o Minor bugfixes:
    - Require that onion keys have exponent 65537 in microdescriptors too.
      Fixes more of bug 3207; bugfix on 0.2.2.26-beta.
    - Tor used to limit HttpProxyAuthenticator values to 48 characters.
      Changed the limit to 512 characters by removing base64 newlines.
      Fixes bug 2752. Fix by Michael Yakubovich.
    - When a client starts or stops using bridges, never use a circuit
      that was built before the configuration change. This behavior could
      put at risk a user who uses bridges to ensure that her traffic
      only goes to the chosen addresses. Bugfix on 0.2.0.3-alpha; fixes
      bug 3200.


Changes in version 0.2.2.26-beta - 2011-05-17
  Tor 0.2.2.26-beta fixes a variety of potential privacy problems. It
  also introduces a new "socksport auto" approach that should make it
  easier to run multiple Tors on the same system, and does a lot of
  cleanup to get us closer to a release candidate.

  o Security/privacy fixes:
    - Replace all potentially sensitive memory comparison operations
      with versions whose runtime does not depend on the data being
      compared. This will help resist a class of attacks where an
      adversary can use variations in timing information to learn
      sensitive data. Fix for one case of bug 3122. (Safe memcmp
      implementation by Robert Ransom based partially on code by DJB.)
    - When receiving a hidden service descriptor, check that it is for
      the hidden service we wanted. Previously, Tor would store any
      hidden service descriptors that a directory gave it, whether it
      wanted them or not. This wouldn't have let an attacker impersonate
      a hidden service, but it did let directories pre-seed a client
      with descriptors that it didn't want. Bugfix on 0.0.6.
    - On SIGHUP, do not clear out all TrackHostExits mappings, client
      DNS cache entries, and virtual address mappings: that's what
      NEWNYM is for. Fixes bug 1345; bugfix on 0.1.0.1-rc.

  o Major features:
    - The options SocksPort, ControlPort, and so on now all accept a
      value "auto" that opens a socket on an OS-selected port. A
      new ControlPortWriteToFile option tells Tor to write its
      actual control port or ports to a chosen file. If the option
      ControlPortFileGroupReadable is set, the file is created as
      group-readable. Now users can run two Tor clients on the same
      system without needing to manually mess with parameters. Resolves
      part of ticket 3076.
    - Set SO_REUSEADDR on all sockets, not just listeners. This should
      help busy exit nodes avoid running out of useable ports just
      because all the ports have been used in the near past. Resolves
      issue 2850.

  o Minor features:
    - New "GETINFO net/listeners/(type)" controller command to return
      a list of addresses and ports that are bound for listeners for a
      given connection type. This is useful when the user has configured
      "SocksPort auto" and the controller needs to know which port got
      chosen. Resolves another part of ticket 3076.
    - Add a new ControlSocketsGroupWritable configuration option: when
      it is turned on, ControlSockets are group-writeable by the default
      group of the current user. Patch by Jérémy Bobbio; implements
      ticket 2972.
    - Tor now refuses to create a ControlSocket in a directory that is
      world-readable (or group-readable if ControlSocketsGroupWritable
      is 0). This is necessary because some operating systems do not
      enforce permissions on an AF_UNIX sockets. Permissions on the
      directory holding the socket, however, seems to work everywhere.
    - Rate-limit a warning about failures to download v2 networkstatus
      documents. Resolves part of bug 1352.
    - Backport code from 0.2.3.x that allows directory authorities to
      clean their microdescriptor caches. Needed to resolve bug 2230.
    - When an HTTPS proxy reports "403 Forbidden", we now explain
      what it means rather than calling it an unexpected status code.
      Closes bug 2503. Patch from Michael Yakubovich.
    - Update to the May 1 2011 Maxmind GeoLite Country database.

  o Minor bugfixes:
    - Authorities now clean their microdesc cache periodically and when
      reading from disk initially, not only when adding new descriptors.
      This prevents a bug where we could lose microdescriptors. Bugfix
      on 0.2.2.6-alpha. Fixes bug 2230.
    - Do not crash when our configuration file becomes unreadable, for
      example due to a permissions change, between when we start up
      and when a controller calls SAVECONF. Fixes bug 3135; bugfix
      on 0.0.9pre6.
    - Avoid a bug that would keep us from replacing a microdescriptor
      cache on Windows. (We would try to replace the file while still
      holding it open. That's fine on Unix, but Windows doesn't let us
      do that.) Bugfix on 0.2.2.6-alpha; bug found by wanoskarnet.
    - Add missing explanations for the authority-related torrc options
      RephistTrackTime, BridgePassword, and V3AuthUseLegacyKey in the
      man page. Resolves issue 2379.
    - As an authority, do not upload our own vote or signature set to
      ourself. It would tell us nothing new, and as of 0.2.2.24-alpha,
      it would get flagged as a duplicate. Resolves bug 3026.
    - Accept hidden service descriptors if we think we might be a hidden
      service directory, regardless of what our consensus says. This
      helps robustness, since clients and hidden services can sometimes
      have a more up-to-date view of the network consensus than we do,
      and if they think that the directory authorities list us a HSDir,
      we might actually be one. Related to bug 2732; bugfix on
      0.2.0.10-alpha.
    - When a controller changes TrackHostExits, remove mappings for
      hosts that should no longer have their exits tracked. Bugfix on
      0.1.0.1-rc.
    - When a controller changes VirtualAddrNetwork, remove any mappings
      for hosts that were automapped to the old network. Bugfix on
      0.1.1.19-rc.
    - When a controller changes one of the AutomapHosts* options, remove
      any mappings for hosts that should no longer be automapped. Bugfix
      on 0.2.0.1-alpha.
    - Do not reset the bridge descriptor download status every time we
      re-parse our configuration or get a configuration change. Fixes
      bug 3019; bugfix on 0.2.0.3-alpha.

  o Minor bugfixes (code cleanup):
    - When loading the microdesc journal, remember its current size.
      In 0.2.2, this helps prevent the microdesc journal from growing
      without limit on authorities (who are the only ones to use it in
      0.2.2). Fixes a part of bug 2230; bugfix on 0.2.2.6-alpha.
      Fix posted by "cypherpunks."
    - The microdesc journal is supposed to get rebuilt only if it is
      at least _half_ the length of the store, not _twice_ the length
      of the store. Bugfix on 0.2.2.6-alpha; fixes part of bug 2230.
    - Fix a potential null-pointer dereference while computing a
      consensus. Bugfix on 0.2.0.3-alpha, found with the help of
      clang's analyzer.
    - Avoid a possible null-pointer dereference when rebuilding the mdesc
      cache without actually having any descriptors to cache. Bugfix on
      0.2.2.6-alpha. Issue discovered using clang's static analyzer.
    - If we fail to compute the identity digest of a v3 legacy keypair,
      warn, and don't use a buffer-full of junk instead. Bugfix on
      0.2.1.1-alpha; fixes bug 3106.
    - Resolve an untriggerable issue in smartlist_string_num_isin(),
      where if the function had ever in the future been used to check
      for the presence of a too-large number, it would have given an
      incorrect result. (Fortunately, we only used it for 16-bit
      values.) Fixes bug 3175; bugfix on 0.1.0.1-rc.
    - Require that introduction point keys and onion handshake keys
      have a public exponent of 65537. Starts to fix bug 3207; bugfix
      on 0.2.0.10-alpha.

  o Removed features:
    - Caches no longer download and serve v2 networkstatus documents
      unless FetchV2Networkstatus flag is set: these documents haven't
      haven't been used by clients or relays since 0.2.0.x. Resolves
      bug 3022.


Changes in version 0.2.3.1-alpha - 2011-05-05
  Tor 0.2.3.1-alpha adds some new experimental features, including support
  for an improved network IO backend, IOCP networking on Windows,
  microdescriptor caching, "fast-start" support for streams, and automatic
  home router configuration. There are also numerous internal improvements
  to try to make the code easier for developers to work with.

  This is the first alpha release in a new series, so expect there to be
  bugs. Users who would rather test out a more stable branch should
  stay with 0.2.2.x for now.

  o Major features:
    - Tor can now optionally build with the "bufferevents" buffered IO
      backend provided by Libevent 2. To use this feature, make sure you
      have the latest possible version of Libevent, and pass the
      --enable-bufferevents flag to configure when building Tor from
      source. This feature will make our networking code more flexible,
      let us stack layers on each other, and let us use more efficient
      zero-copy transports where available.
    - As an experimental feature, Tor can use IOCP for networking on Windows.
      Once this code is tuned and optimized, it promises much better
      performance than the select-based backend we've used in the past. To
      try this feature, you must build Tor with Libevent 2, configure Tor
      with the "bufferevents" buffered IO backend, and add "DisableIOCP 0" to
      your torrc. There are known bugs here: only try this if you can help
      debug it as it breaks.
    - The EntryNodes option can now include country codes like {de} or IP
      addresses or network masks. Previously we had disallowed these options
      because we didn't have an efficient way to keep the list up to
      date. Fixes bug 1982, but see bug 2798 for an unresolved issue here.
    - Exit nodes now accept and queue data on not-yet-connected streams.
      Previously, the client wasn't allowed to send data until the stream was
      connected, which slowed down all connections. This change will enable
      clients to perform a "fast-start" on streams and send data without
      having to wait for a confirmation that the stream has opened. (Patch
      from Ian Goldberg; implements the server side of Proposal 174.)
    - Tor now has initial support for automatic port mapping on the many
      home routers that support NAT-PMP or UPnP. (Not yet supported on
      Windows). To build the support code, you'll need to have libnatpnp
      library and/or the libminiupnpc library, and you'll need to enable the
      feature specifically by passing "--enable-upnp" and/or
      "--enable-natpnp" to configure. To turn it on, use the new
      PortForwarding option.
    - Caches now download, cache, and serve multiple "flavors" of the
      consensus, including a flavor that describes microdescriptors.
    - Caches now download, cache, and serve microdescriptors -- small
      summaries of router descriptors that are authenticated by all of the
      directory authorities. Once enough caches are running this code,
      clients will be able to save significant amounts of directory bandwidth
      by downloading microdescriptors instead of router descriptors.

  o Minor features:
    - Make logging resolution configurable with a new LogTimeGranularity
      option, and change the default from 1 millisecond to 1 second.
      Implements enhancement 1668.
    - We log which torrc file we're using on startup. Implements ticket
      2444.
    - Ordinarily, Tor does not count traffic from private addresses (like
      127.0.0.1 or 10.0.0.1) when calculating rate limits or accounting.
      There is now a new option, CountPrivateBandwidth, to disable this
      behavior. Patch from Daniel Cagara.
    - New --enable-static-tor configure option for building Tor as
      statically as possible. Idea, general hackery and thoughts from
      Alexei Czeskis, John Gilmore, Jacob Appelbaum. Implements ticket
      2702.
    - If you set the NumCPUs option to 0, Tor will now try to detect how
      many CPUs you have. This is the new default behavior.
    - Turn on directory request statistics by default and include them in
      extra-info descriptors. Don't break if we have no GeoIP database.
    - Relays that set "ConnDirectionStatistics 1" write statistics on the
      bidirectional use of connections to disk every 24 hours.
    - Add a GeoIP file digest to the extra-info descriptor. Implements
      enhancement 1883.
    - The NodeFamily option -- which let you declare that you want to
      consider nodes to be part of a family whether they list themselves
      that way or not -- now allows IP address ranges and country codes.
    - Add a new 'Heartbeat' log message type to periodically log a message
      describing Tor's status at level Notice. This feature is meant for
      operators who log at notice, and want to make sure that their Tor
      server is still working. Implementation by George Kadianakis.

  o Minor bugfixes (on 0.2.2.25-alpha):
    - When loading the microdesc journal, remember its current size.
      In 0.2.2, this helps prevent the microdesc journal from growing
      without limit on authorities (who are the only ones to use it in
      0.2.2). Fixes a part of bug 2230; bugfix on 0.2.2.6-alpha.
      Fix posted by "cypherpunks."
    - The microdesc journal is supposed to get rebuilt only if it is
      at least _half_ the length of the store, not _twice_ the length
      of the store. Bugfix on 0.2.2.6-alpha; fixes part of bug 2230.
    - If as an authority we fail to compute the identity digest of a v3
      legacy keypair, warn, and don't use a buffer-full of junk instead.
      Bugfix on 0.2.1.1-alpha; fixes bug 3106.
    - Authorities now clean their microdesc cache periodically and when
      reading from disk initially, not only when adding new descriptors.
      This prevents a bug where we could lose microdescriptors. Bugfix
      on 0.2.2.6-alpha.

  o Minor features (controller):
    - Add a new SIGNAL event to the controller interface so that
      controllers can be notified when Tor handles a signal. Resolves
      issue 1955. Patch by John Brooks.
    - Add a new GETINFO option to get total bytes read and written. Patch
      from pipe, revised by atagar. Resolves ticket 2345.
    - Implement some GETINFO controller fields to provide information about
      the Tor process's pid, euid, username, and resource limits.

  o Build changes:
    - Our build system requires automake 1.6 or later to create the
      Makefile.in files. Previously, you could have used 1.4.
      This only affects developers and people building Tor from git;
      people who build Tor from the source distribution without changing
      the Makefile.am files should be fine.
    - Our autogen.sh script uses autoreconf to launch autoconf, automake, and
      so on. This is more robust against some of the failure modes
      associated with running the autotools pieces on their own.

  o Minor packaging issues:
    - On OpenSUSE, create the /var/run/tor directory on startup if it is not
      already created. Patch from Andreas Stieger. Fixes bug 2573.

  o Code simplifications and refactoring:
    - A major revision to our internal node-selecting and listing logic.
      Tor already had at least two major ways to look at the question of
      "which Tor servers do we know about": a list of router descriptors,
      and a list of entries in the current consensus. With
      microdescriptors, we're adding a third. Having so many systems
      without an abstraction layer over them was hurting the codebase.
      Now, we have a new "node_t" abstraction that presents a consistent
      interface to a client's view of a Tor node, and holds (nearly) all
      of the mutable state formerly in routerinfo_t and routerstatus_t.
    - The helper programs tor-gencert, tor-resolve, and tor-checkkey
      no longer link against Libevent: they never used it, but
      our library structure used to force them to link it.

  o Removed features:
    - Remove some old code to work around even older versions of Tor that
      used forked processes to handle DNS requests. Such versions of Tor
      are no longer in use as servers.

  o Documentation fixes:
    - Correct a broken faq link in the INSTALL file. Fixes bug 2307.
    - Add missing documentation for the authority-related torrc options
      RephistTrackTime, BridgePassword, and V3AuthUseLegacyKey. Resolves
      issue 2379.


Changes in version 0.2.2.25-alpha - 2011-04-29
  Tor 0.2.2.25-alpha fixes many bugs: hidden service clients are more
  robust, routers no longer overreport their bandwidth, Win7 should crash
  a little less, and NEWNYM (as used by Vidalia's "new identity" button)
  now prevents hidden service-related activity from being linkable. It
  provides more information to Vidalia so you can see if your bridge is
  working. Also, 0.2.2.25-alpha revamps the Entry/Exit/ExcludeNodes and
  StrictNodes configuration options to make them more reliable, more
  understandable, and more regularly applied. If you use those options,
  please see the revised documentation for them in the manual page.

  o Major bugfixes:
    - Relays were publishing grossly inflated bandwidth values because
      they were writing their state files wrong--now they write the
      correct value. Also, resume reading bandwidth history from the
      state file correctly. Fixes bug 2704; bugfix on 0.2.2.23-alpha.
    - Improve hidden service robustness: When we find that we have
      extended a hidden service's introduction circuit to a relay not
      listed as an introduction point in the HS descriptor we currently
      have, retry with an introduction point from the current
      descriptor. Previously we would just give up. Fixes bugs 1024 and
      1930; bugfix on 0.2.0.10-alpha.
    - Clients now stop trying to use an exit node associated with a given
      destination by TrackHostExits if they fail to reach that exit node.
      Fixes bug 2999. Bugfix on 0.2.0.20-rc.
    - Fix crash bug on platforms where gmtime and localtime can return
      NULL. Windows 7 users were running into this one. Fixes part of bug
      2077. Bugfix on all versions of Tor. Found by boboper.

  o Security and stability fixes:
    - Don't double-free a parsable, but invalid, microdescriptor, even if
      it is followed in the blob we're parsing by an unparsable
      microdescriptor. Fixes an issue reported in a comment on bug 2954.
      Bugfix on 0.2.2.6-alpha; fix by "cypherpunks".
    - If the Nickname configuration option isn't given, Tor would pick a
      nickname based on the local hostname as the nickname for a relay.
      Because nicknames are not very important in today's Tor and the
      "Unnamed" nickname has been implemented, this is now problematic
      behavior: It leaks information about the hostname without being
      useful at all. Fixes bug 2979; bugfix on 0.1.2.2-alpha, which
      introduced the Unnamed nickname. Reported by tagnaq.
    - Fix an uncommon assertion failure when running with DNSPort under
      heavy load. Fixes bug 2933; bugfix on 0.2.0.1-alpha.
    - Avoid linkability based on cached hidden service descriptors: forget
      all hidden service descriptors cached as a client when processing a
      SIGNAL NEWNYM command. Fixes bug 3000; bugfix on 0.0.6.

  o Major features:
    - Export GeoIP information on bridge usage to controllers even if we
      have not yet been running for 24 hours. Now Vidalia bridge operators
      can get more accurate and immediate feedback about their
      contributions to the network.

  o Major features and bugfixes (node selection):
    - Revise and reconcile the meaning of the ExitNodes, EntryNodes,
      ExcludeEntryNodes, ExcludeExitNodes, ExcludeNodes, and StrictNodes
      options. Previously, we had been ambiguous in describing what
      counted as an "exit" node, and what operations exactly "StrictNodes
      0" would permit. This created confusion when people saw nodes built
      through unexpected circuits, and made it hard to tell real bugs from
      surprises. Now the intended behavior is:
        . "Exit", in the context of ExitNodes and ExcludeExitNodes, means
          a node that delivers user traffic outside the Tor network.
        . "Entry", in the context of EntryNodes, means a node used as the
          first hop of a multihop circuit. It doesn't include direct
          connections to directory servers.
        . "ExcludeNodes" applies to all nodes.
        . "StrictNodes" changes the behavior of ExcludeNodes only. When
          StrictNodes is set, Tor should avoid all nodes listed in
          ExcludeNodes, even when it will make user requests fail. When
          StrictNodes is *not* set, then Tor should follow ExcludeNodes
          whenever it can, except when it must use an excluded node to
          perform self-tests, connect to a hidden service, provide a
          hidden service, fulfill a .exit request, upload directory
          information, or fetch directory information.
      Collectively, the changes to implement the behavior fix bug 1090.
    - ExcludeNodes now takes precedence over EntryNodes and ExitNodes: if
      a node is listed in both, it's treated as excluded.
    - ExcludeNodes now applies to directory nodes -- as a preference if
      StrictNodes is 0, or an absolute requirement if StrictNodes is 1.
      Don't exclude all the directory authorities and set StrictNodes to 1
      unless you really want your Tor to break.
    - ExcludeNodes and ExcludeExitNodes now override exit enclaving.
    - ExcludeExitNodes now overrides .exit requests.
    - We don't use bridges listed in ExcludeNodes.
    - When StrictNodes is 1:
       . We now apply ExcludeNodes to hidden service introduction points
         and to rendezvous points selected by hidden service users. This
         can make your hidden service less reliable: use it with caution!
       . If we have used ExcludeNodes on ourself, do not try relay
         reachability self-tests.
       . If we have excluded all the directory authorities, we will not
         even try to upload our descriptor if we're a relay.
       . Do not honor .exit requests to an excluded node.
    - Remove a misfeature that caused us to ignore the Fast/Stable flags
      when ExitNodes is set. Bugfix on 0.2.2.7-alpha.
    - When the set of permitted nodes changes, we now remove any mappings
      introduced via TrackExitHosts to now-excluded nodes. Bugfix on
      0.1.0.1-rc.
    - We never cannibalize a circuit that had excluded nodes on it, even
      if StrictNodes is 0. Bugfix on 0.1.0.1-rc.
    - Revert a change where we would be laxer about attaching streams to
      circuits than when building the circuits. This was meant to prevent
      a set of bugs where streams were never attachable, but our improved
      code here should make this unnecessary. Bugfix on 0.2.2.7-alpha.
    - Keep track of how many times we launch a new circuit to handle a
      given stream. Too many launches could indicate an inconsistency
      between our "launch a circuit to handle this stream" logic and our
      "attach this stream to one of the available circuits" logic.
    - Improve log messages related to excluded nodes.

  o Minor bugfixes:
    - Fix a spurious warning when moving from a short month to a long
      month on relays with month-based BandwidthAccounting. Bugfix on
      0.2.2.17-alpha; fixes bug 3020.
    - When a client finds that an origin circuit has run out of 16-bit
      stream IDs, we now mark it as unusable for new streams. Previously,
      we would try to close the entire circuit. Bugfix on 0.0.6.
    - Add a forgotten cast that caused a compile warning on OS X 10.6.
      Bugfix on 0.2.2.24-alpha.
    - Be more careful about reporting the correct error from a failed
      connect() system call. Under some circumstances, it was possible to
      look at an incorrect value for errno when sending the end reason.
      Bugfix on 0.1.0.1-rc.
    - Correctly handle an "impossible" overflow cases in connection byte
      counting, where we write or read more than 4GB on an edge connection
      in a single second. Bugfix on 0.1.2.8-beta.
    - Correct the warning displayed when a rendezvous descriptor exceeds
      the maximum size. Fixes bug 2750; bugfix on 0.2.1.5-alpha. Found by
      John Brooks.
    - Clients and hidden services now use HSDir-flagged relays for hidden
      service descriptor downloads and uploads even if the relays have no
      DirPort set and the client has disabled TunnelDirConns. This will
      eventually allow us to give the HSDir flag to relays with no
      DirPort. Fixes bug 2722; bugfix on 0.2.1.6-alpha.
    - Downgrade "no current certificates known for authority" message from
      Notice to Info. Fixes bug 2899; bugfix on 0.2.0.10-alpha.
    - Make the SIGNAL DUMP control-port command work on FreeBSD. Fixes bug
      2917. Bugfix on 0.1.1.1-alpha.
    - Only limit the lengths of single HS descriptors, even when multiple
      HS descriptors are published to an HSDir relay in a single POST
      operation. Fixes bug 2948; bugfix on 0.2.1.5-alpha. Found by hsdir.
    - Write the current time into the LastWritten line in our state file,
      rather than the time from the previous write attempt. Also, stop
      trying to use a time of -1 in our log statements. Fixes bug 3039;
      bugfix on 0.2.2.14-alpha.
    - Be more consistent in our treatment of file system paths. "~" should
      get expanded to the user's home directory in the Log config option.
      Fixes bug 2971; bugfix on 0.2.0.1-alpha, which introduced the
      feature for the -f and --DataDirectory options.

  o Minor features:
    - Make sure every relay writes a state file at least every 12 hours.
      Previously, a relay could go for weeks without writing its state
      file, and on a crash could lose its bandwidth history, capacity
      estimates, client country statistics, and so on. Addresses bug 3012.
    - Send END_STREAM_REASON_NOROUTE in response to EHOSTUNREACH errors.
      Clients before 0.2.1.27 didn't handle NOROUTE correctly, but such
      clients are already deprecated because of security bugs.
    - Don't allow v0 hidden service authorities to act as clients.
      Required by fix for bug 3000.
    - Ignore SIGNAL NEWNYM commands on relay-only Tor instances. Required
      by fix for bug 3000.
    - Ensure that no empty [dirreq-](read|write)-history lines are added
      to an extrainfo document. Implements ticket 2497.

  o Code simplification and refactoring:
    - Remove workaround code to handle directory responses from servers
      that had bug 539 (they would send HTTP status 503 responses _and_
      send a body too). Since only server versions before
      0.2.0.16-alpha/0.1.2.19 were affected, there is no longer reason to
      keep the workaround in place.
    - Remove the old 'fuzzy time' logic. It was supposed to be used for
      handling calculations where we have a known amount of clock skew and
      an allowed amount of unknown skew. But we only used it in three
      places, and we never adjusted the known/unknown skew values. This is
      still something we might want to do someday, but if we do, we'll
      want to do it differently.
    - Avoid signed/unsigned comparisons by making SIZE_T_CEILING unsigned.
      None of the cases where we did this before were wrong, but by making
      this change we avoid warnings. Fixes bug 2475; bugfix on 0.2.1.28.
    - Use GetTempDir to find the proper temporary directory location on
      Windows when generating temporary files for the unit tests. Patch by
      Gisle Vanem.


Changes in version 0.2.2.24-alpha - 2011-04-08
  Tor 0.2.2.24-alpha fixes a variety of bugs, including a big bug that
  prevented Tor clients from effectively using "multihomed" bridges,
  that is, bridges that listen on multiple ports or IP addresses so users
  can continue to use some of their addresses even if others get blocked.

  o Major bugfixes:
    - Fix a bug where bridge users who configure the non-canonical
      address of a bridge automatically switch to its canonical
      address. If a bridge listens at more than one address, it should be
      able to advertise those addresses independently and any non-blocked
      addresses should continue to work. Bugfix on Tor 0.2.0.x. Fixes
      bug 2510.
    - If you configured Tor to use bridge A, and then quit and
      configured Tor to use bridge B instead, it would happily continue
      to use bridge A if it's still reachable. While this behavior is
      a feature if your goal is connectivity, in some scenarios it's a
      dangerous bug. Bugfix on Tor 0.2.0.1-alpha; fixes bug 2511.
    - Directory authorities now use data collected from their own
      uptime observations when choosing whether to assign the HSDir flag
      to relays, instead of trusting the uptime value the relay reports in
      its descriptor. This change helps prevent an attack where a small
      set of nodes with frequently-changing identity keys can blackhole
      a hidden service. (Only authorities need upgrade; others will be
      fine once they do.) Bugfix on 0.2.0.10-alpha; fixes bug 2709.

  o Minor bugfixes:
    - When we restart our relay, we might get a successful connection
      from the outside before we've started our reachability tests,
      triggering a warning: "ORPort found reachable, but I have no
      routerinfo yet. Failing to inform controller of success." This
      bug was harmless unless Tor is running under a controller
      like Vidalia, in which case the controller would never get a
      REACHABILITY_SUCCEEDED status event. Bugfix on 0.1.2.6-alpha;
      fixes bug 1172.
    - Make directory authorities more accurate at recording when
      relays that have failed several reachability tests became
      unreachable, so we can provide more accuracy at assigning Stable,
      Guard, HSDir, etc flags. Bugfix on 0.2.0.6-alpha. Resolves bug 2716.
    - Fix an issue that prevented static linking of libevent on
      some platforms (notably Linux). Fixes bug 2698; bugfix on
      versions 0.2.1.23/0.2.2.8-alpha (the versions introducing
      the --with-static-libevent configure option).
    - We now ask the other side of a stream (the client or the exit)
      for more data on that stream when the amount of queued data on
      that stream dips low enough. Previously, we wouldn't ask the
      other side for more data until either it sent us more data (which
      it wasn't supposed to do if it had exhausted its window!) or we
      had completely flushed all our queued data. This flow control fix
      should improve throughput. Fixes bug 2756; bugfix on the earliest
      released versions of Tor (svn commit r152).
    - Avoid a double-mark-for-free warning when failing to attach a
      transparent proxy connection. (We thought we had fixed this in
      0.2.2.23-alpha, but it turns out our fix was checking the wrong
      connection.) Fixes bug 2757; bugfix on 0.1.2.1-alpha (the original
      bug) and 0.2.2.23-alpha (the incorrect fix).
    - When warning about missing zlib development packages during compile,
      give the correct package names. Bugfix on 0.2.0.1-alpha.

  o Minor features:
    - Directory authorities now log the source of a rejected POSTed v3
      networkstatus vote.
    - Make compilation with clang possible when using
      --enable-gcc-warnings by removing two warning options that clang
      hasn't implemented yet and by fixing a few warnings. Implements
      ticket 2696.
    - When expiring circuits, use microsecond timers rather than
      one-second timers. This can avoid an unpleasant situation where a
      circuit is launched near the end of one second and expired right
      near the beginning of the next, and prevent fluctuations in circuit
      timeout values.
    - Use computed circuit-build timeouts to decide when to launch
      parallel introduction circuits for hidden services. (Previously,
      we would retry after 15 seconds.)
    - Update to the April 1 2011 Maxmind GeoLite Country database.

  o Packaging fixes:
    - Create the /var/run/tor directory on startup on OpenSUSE if it is
      not already created. Patch from Andreas Stieger. Fixes bug 2573.

  o Documentation changes:
    - Modernize the doxygen configuration file slightly. Fixes bug 2707.
    - Resolve all doxygen warnings except those for missing documentation.
      Fixes bug 2705.
    - Add doxygen documentation for more functions, fields, and types.


Changes in version 0.2.2.23-alpha - 2011-03-08
  Tor 0.2.2.23-alpha lets relays record their bandwidth history so when
  they restart they don't lose their bandwidth capacity estimate. This
  release also fixes a diverse set of user-facing bugs, ranging from
  relays overrunning their rate limiting to clients falsely warning about
  clock skew to bridge descriptor leaks by our bridge directory authority.

  o Major bugfixes:
    - Stop sending a CLOCK_SKEW controller status event whenever
      we fetch directory information from a relay that has a wrong clock.
      Instead, only inform the controller when it's a trusted authority
      that claims our clock is wrong. Bugfix on 0.1.2.6-alpha; fixes
      the rest of bug 1074.
    - Fix an assert in parsing router descriptors containing IPv6
      addresses. This one took down the directory authorities when
      somebody tried some experimental code. Bugfix on 0.2.1.3-alpha.
    - Make the bridge directory authority refuse to answer directory
      requests for "all" descriptors. It used to include bridge
      descriptors in its answer, which was a major information leak.
      Found by "piebeer". Bugfix on 0.2.0.3-alpha.
    - If relays set RelayBandwidthBurst but not RelayBandwidthRate,
      Tor would ignore their RelayBandwidthBurst setting,
      potentially using more bandwidth than expected. Bugfix on
      0.2.0.1-alpha. Reported by Paul Wouters. Fixes bug 2470.
    - Ignore and warn if the user mistakenly sets "PublishServerDescriptor
      hidserv" in her torrc. The 'hidserv' argument never controlled
      publication of hidden service descriptors. Bugfix on 0.2.0.1-alpha.

  o Major features:
    - Relays now save observed peak bandwidth throughput rates to their
      state file (along with total usage, which was already saved)
      so that they can determine their correct estimated bandwidth on
      restart. Resolves bug 1863, where Tor relays would reset their
      estimated bandwidth to 0 after restarting.
    - Directory authorities now take changes in router IP address and
      ORPort into account when determining router stability. Previously,
      if a router changed its IP or ORPort, the authorities would not
      treat it as having any downtime for the purposes of stability
      calculation, whereas clients would experience downtime since the
      change could take a while to propagate to them. Resolves issue 1035.
    - Enable Address Space Layout Randomization (ASLR) and Data Execution
      Prevention (DEP) by default on Windows to make it harder for
      attackers to exploit vulnerabilities. Patch from John Brooks.

  o Minor bugfixes (on 0.2.1.x and earlier):
    - Fix a rare crash bug that could occur when a client was configured
      with a large number of bridges. Fixes bug 2629; bugfix on
      0.2.1.2-alpha. Bugfix by trac user "shitlei".
    - Avoid a double mark-for-free warning when failing to attach a
      transparent proxy connection. Bugfix on 0.1.2.1-alpha. Fixes
      bug 2279.
    - Correctly detect failure to allocate an OpenSSL BIO. Fixes bug 2378;
      found by "cypherpunks". This bug was introduced before the first
      Tor release, in svn commit r110.
    - Country codes aren't supported in EntryNodes until 0.2.3.x, so
      don't mention them in the manpage. Fixes bug 2450; issue
      spotted by keb and G-Lo.
    - Fix a bug in bandwidth history state parsing that could have been
      triggered if a future version of Tor ever changed the timing
      granularity at which bandwidth history is measured. Bugfix on
      Tor 0.1.1.11-alpha.
    - When a relay decides that its DNS is too broken for it to serve
      as an exit server, it advertised itself as a non-exit, but
      continued to act as an exit. This could create accidental
      partitioning opportunities for users. Instead, if a relay is
      going to advertise reject *:* as its exit policy, it should
      really act with exit policy "reject *:*". Fixes bug 2366.
      Bugfix on Tor 0.1.2.5-alpha. Bugfix by user "postman" on trac.
    - In the special case where you configure a public exit relay as your
      bridge, Tor would be willing to use that exit relay as the last
      hop in your circuit as well. Now we fail that circuit instead.
      Bugfix on 0.2.0.12-alpha. Fixes bug 2403. Reported by "piebeer".
    - Fix a bug with our locking implementation on Windows that couldn't
      correctly detect when a file was already locked. Fixes bug 2504,
      bugfix on 0.2.1.6-alpha.
    - Fix IPv6-related connect() failures on some platforms (BSD, OS X).
      Bugfix on 0.2.0.3-alpha; fixes first part of bug 2660. Patch by
      "piebeer".
    - Set target port in get_interface_address6() correctly. Bugfix
      on 0.1.1.4-alpha and 0.2.0.3-alpha; fixes second part of bug 2660.
    - Directory authorities are now more robust to hops back in time
      when calculating router stability. Previously, if a run of uptime
      or downtime appeared to be negative, the calculation could give
      incorrect results. Bugfix on 0.2.0.6-alpha; noticed when fixing
      bug 1035.
    - Fix an assert that got triggered when using the TestingTorNetwork
      configuration option and then issuing a GETINFO config-text control
      command. Fixes bug 2250; bugfix on 0.2.1.2-alpha.

  o Minor bugfixes (on 0.2.2.x):
    - Clients should not weight BadExit nodes as Exits in their node
      selection. Similarly, directory authorities should not count BadExit
      bandwidth as Exit bandwidth when computing bandwidth-weights.
      Bugfix on 0.2.2.10-alpha; fixes bug 2203.
    - Correctly clear our dir_read/dir_write history when there is an
      error parsing any bw history value from the state file. Bugfix on
      Tor 0.2.2.15-alpha.
    - Resolve a bug in verifying signatures of directory objects
      with digests longer than SHA1. Bugfix on 0.2.2.20-alpha.
      Fixes bug 2409. Found by "piebeer".
    - Bridge authorities no longer crash on SIGHUP when they try to
      publish their relay descriptor to themselves. Fixes bug 2572. Bugfix
      on 0.2.2.22-alpha.

  o Minor features:
    - Log less aggressively about circuit timeout changes, and improve
      some other circuit timeout messages. Resolves bug 2004.
    - Log a little more clearly about the times at which we're no longer
      accepting new connections. Resolves bug 2181.
    - Reject attempts at the client side to open connections to private
      IP addresses (like 127.0.0.1, 10.0.0.1, and so on) with
      a randomly chosen exit node. Attempts to do so are always
      ill-defined, generally prevented by exit policies, and usually
      in error. This will also help to detect loops in transparent
      proxy configurations. You can disable this feature by setting
      "ClientRejectInternalAddresses 0" in your torrc.
    - Always treat failure to allocate an RSA key as an unrecoverable
      allocation error.
    - Update to the March 1 2011 Maxmind GeoLite Country database.

  o Minor features (log subsystem):
    - Add documentation for configuring logging at different severities in
      different log domains. We've had this feature since 0.2.1.1-alpha,
      but for some reason it never made it into the manpage. Fixes
      bug 2215.
    - Make it simpler to specify "All log domains except for A and B".
      Previously you needed to say "[*,~A,~B]". Now you can just say
      "[~A,~B]".
    - Add a "LogMessageDomains 1" option to include the domains of log
      messages along with the messages. Without this, there's no way
      to use log domains without reading the source or doing a lot
      of guessing.

  o Packaging changes:
    - Stop shipping the Tor specs files and development proposal documents
      in the tarball. They are now in a separate git repository at
      git://git.torproject.org/torspec.git


Changes in version 0.2.1.30 - 2011-02-23
  Tor 0.2.1.30 fixes a variety of less critical bugs. The main other
  change is a slight tweak to Tor's TLS handshake that makes relays
  and bridges that run this new version reachable from Iran again.
  We don't expect this tweak will win the arms race long-term, but it
  buys us time until we roll out a better solution.

  o Major bugfixes:
    - Stop sending a CLOCK_SKEW controller status event whenever
      we fetch directory information from a relay that has a wrong clock.
      Instead, only inform the controller when it's a trusted authority
      that claims our clock is wrong. Bugfix on 0.1.2.6-alpha; fixes
      the rest of bug 1074.
    - Fix a bounds-checking error that could allow an attacker to
      remotely crash a directory authority. Bugfix on 0.2.1.5-alpha.
      Found by "piebeer".
    - If relays set RelayBandwidthBurst but not RelayBandwidthRate,
      Tor would ignore their RelayBandwidthBurst setting,
      potentially using more bandwidth than expected. Bugfix on
      0.2.0.1-alpha. Reported by Paul Wouters. Fixes bug 2470.
    - Ignore and warn if the user mistakenly sets "PublishServerDescriptor
      hidserv" in her torrc. The 'hidserv' argument never controlled
      publication of hidden service descriptors. Bugfix on 0.2.0.1-alpha.

  o Minor features:
    - Adjust our TLS Diffie-Hellman parameters to match those used by
      Apache's mod_ssl.
    - Update to the February 1 2011 Maxmind GeoLite Country database.

  o Minor bugfixes:
    - Check for and reject overly long directory certificates and
      directory tokens before they have a chance to hit any assertions.
      Bugfix on 0.2.1.28. Found by "doorss".
    - Bring the logic that gathers routerinfos and assesses the
      acceptability of circuits into line. This prevents a Tor OP from
      getting locked in a cycle of choosing its local OR as an exit for a
      path (due to a .exit request) and then rejecting the circuit because
      its OR is not listed yet. It also prevents Tor clients from using an
      OR running in the same instance as an exit (due to a .exit request)
      if the OR does not meet the same requirements expected of an OR
      running elsewhere. Fixes bug 1859; bugfix on 0.1.0.1-rc.

  o Packaging changes:
    - Stop shipping the Tor specs files and development proposal documents
      in the tarball. They are now in a separate git repository at
      git://git.torproject.org/torspec.git
    - Do not include Git version tags as though they are SVN tags when
      generating a tarball from inside a repository that has switched
      between branches. Bugfix on 0.2.1.15-rc; fixes bug 2402.


Changes in version 0.2.2.22-alpha - 2011-01-25
  Tor 0.2.2.22-alpha fixes a few more less-critical security issues. The
  main other change is a slight tweak to Tor's TLS handshake that makes
  relays and bridges that run this new version reachable from Iran again.
  We don't expect this tweak will win the arms race long-term, but it
  will buy us a bit more time until we roll out a better solution.

  o Major bugfixes:
    - Fix a bounds-checking error that could allow an attacker to
      remotely crash a directory authority. Bugfix on 0.2.1.5-alpha.
      Found by "piebeer".
    - Don't assert when changing from bridge to relay or vice versa
      via the controller. The assert happened because we didn't properly
      initialize our keys in this case. Bugfix on 0.2.2.18-alpha; fixes
      bug 2433. Reported by bastik.

  o Minor features:
    - Adjust our TLS Diffie-Hellman parameters to match those used by
      Apache's mod_ssl.
    - Provide a log message stating which geoip file we're parsing
      instead of just stating that we're parsing the geoip file.
      Implements ticket 2432.

  o Minor bugfixes:
    - Check for and reject overly long directory certificates and
      directory tokens before they have a chance to hit any assertions.
      Bugfix on 0.2.1.28 / 0.2.2.20-alpha. Found by "doorss".


Changes in version 0.2.2.21-alpha - 2011-01-15
  Tor 0.2.2.21-alpha includes all the patches from Tor 0.2.1.29, which
  continues our recent code security audit work. The main fix resolves
  a remote heap overflow vulnerability that can allow remote code
  execution (CVE-2011-0427). Other fixes address a variety of assert
  and crash bugs, most of which we think are hard to exploit remotely.

  o Major bugfixes (security), also included in 0.2.1.29:
    - Fix a heap overflow bug where an adversary could cause heap
      corruption. This bug probably allows remote code execution
      attacks. Reported by "debuger". Fixes CVE-2011-0427. Bugfix on
      0.1.2.10-rc.
    - Prevent a denial-of-service attack by disallowing any
      zlib-compressed data whose compression factor is implausibly
      high. Fixes part of bug 2324; reported by "doorss".
    - Zero out a few more keys in memory before freeing them. Fixes
      bug 2384 and part of bug 2385. These key instances found by
      "cypherpunks", based on Andrew Case's report about being able
      to find sensitive data in Tor's memory space if you have enough
      permissions. Bugfix on 0.0.2pre9.

  o Major bugfixes (crashes), also included in 0.2.1.29:
    - Prevent calls to Libevent from inside Libevent log handlers.
      This had potential to cause a nasty set of crashes, especially
      if running Libevent with debug logging enabled, and running
      Tor with a controller watching for low-severity log messages.
      Bugfix on 0.1.0.2-rc. Fixes bug 2190.
    - Add a check for SIZE_T_MAX to tor_realloc() to try to avoid
      underflow errors there too. Fixes the other part of bug 2324.
    - Fix a bug where we would assert if we ever had a
      cached-descriptors.new file (or another file read directly into
      memory) of exactly SIZE_T_CEILING bytes. Fixes bug 2326; bugfix
      on 0.2.1.25. Found by doorss.
    - Fix some potential asserts and parsing issues with grossly
      malformed router caches. Fixes bug 2352; bugfix on Tor 0.2.1.27.
      Found by doorss.

  o Minor bugfixes (other), also included in 0.2.1.29:
    - Fix a bug with handling misformed replies to reverse DNS lookup
      requests in DNSPort. Bugfix on Tor 0.2.0.1-alpha. Related to a
      bug reported by doorss.
    - Fix compilation on mingw when a pthreads compatibility library
      has been installed. (We don't want to use it, so we shouldn't
      be including pthread.h.) Fixes bug 2313; bugfix on 0.1.0.1-rc.
    - Fix a bug where we would declare that we had run out of virtual
      addresses when the address space was only half-exhausted. Bugfix
      on 0.1.2.1-alpha.
    - Correctly handle the case where AutomapHostsOnResolve is set but
      no virtual addresses are available. Fixes bug 2328; bugfix on
      0.1.2.1-alpha. Bug found by doorss.
    - Correctly handle wrapping around when we run out of virtual
      address space. Found by cypherpunks; bugfix on 0.2.0.5-alpha.

  o Minor features, also included in 0.2.1.29:
    - Update to the January 1 2011 Maxmind GeoLite Country database.
    - Introduce output size checks on all of our decryption functions.

  o Build changes, also included in 0.2.1.29:
    - Tor does not build packages correctly with Automake 1.6 and earlier;
      added a check to Makefile.am to make sure that we're building with
      Automake 1.7 or later.
    - The 0.2.1.28 tarball was missing src/common/OpenBSD_malloc_Linux.c
      because we built it with a too-old version of automake. Thus that
      release broke ./configure --enable-openbsd-malloc, which is popular
      among really fast exit relays on Linux.

  o Major bugfixes, new in 0.2.2.21-alpha:
    - Prevent crash/heap corruption when the cbtnummodes consensus
      parameter is set to 0 or large values. Fixes bug 2317; bugfix
      on 0.2.2.14-alpha.

  o Major features, new in 0.2.2.21-alpha:
    - Introduce minimum/maximum values that clients will believe
      from the consensus. Now we'll have a better chance to avoid crashes
      or worse when a consensus param has a weird value.

  o Minor features, new in 0.2.2.21-alpha:
    - Make sure to disable DirPort if running as a bridge. DirPorts aren't
      used on bridges, and it makes bridge scanning somewhat easier.
    - If writing the state file to disk fails, wait up to an hour before
      retrying again, rather than trying again each second. Fixes bug
      2346; bugfix on Tor 0.1.1.3-alpha.
    - Make Libevent log messages get delivered to controllers later,
      and not from inside the Libevent log handler. This prevents unsafe
      reentrant Libevent calls while still letting the log messages
      get through.
    - Detect platforms that brokenly use a signed size_t, and refuse to
      build there. Found and analyzed by doorss and rransom.
    - Fix a bunch of compile warnings revealed by mingw with gcc 4.5.
      Resolves bug 2314.

  o Minor bugfixes, new in 0.2.2.21-alpha:
    - Handle SOCKS messages longer than 128 bytes long correctly, rather
      than waiting forever for them to finish. Fixes bug 2330; bugfix
      on 0.2.0.16-alpha. Found by doorss.
    - Add assertions to check for overflow in arguments to
      base32_encode() and base32_decode(); fix a signed-unsigned
      comparison there too. These bugs are not actually reachable in Tor,
      but it's good to prevent future errors too. Found by doorss.
    - Correctly detect failures to create DNS requests when using Libevent
      versions before v2. (Before Libevent 2, we used our own evdns
      implementation. Its return values for Libevent's evdns_resolve_*()
      functions are not consistent with those from Libevent.) Fixes bug
      2363; bugfix on 0.2.2.6-alpha. Found by "lodger".

  o Documentation, new in 0.2.2.21-alpha:
    - Document the default socks host and port (127.0.0.1:9050) for
      tor-resolve.


Changes in version 0.2.1.29 - 2011-01-15
  Tor 0.2.1.29 continues our recent code security audit work. The main
  fix resolves a remote heap overflow vulnerability that can allow remote
  code execution. Other fixes address a variety of assert and crash bugs,
  most of which we think are hard to exploit remotely.

  o Major bugfixes (security):
    - Fix a heap overflow bug where an adversary could cause heap
      corruption. This bug probably allows remote code execution
      attacks. Reported by "debuger". Fixes CVE-2011-0427. Bugfix on
      0.1.2.10-rc.
    - Prevent a denial-of-service attack by disallowing any
      zlib-compressed data whose compression factor is implausibly
      high. Fixes part of bug 2324; reported by "doorss".
    - Zero out a few more keys in memory before freeing them. Fixes
      bug 2384 and part of bug 2385. These key instances found by
      "cypherpunks", based on Andrew Case's report about being able
      to find sensitive data in Tor's memory space if you have enough
      permissions. Bugfix on 0.0.2pre9.

  o Major bugfixes (crashes):
    - Prevent calls to Libevent from inside Libevent log handlers.
      This had potential to cause a nasty set of crashes, especially
      if running Libevent with debug logging enabled, and running
      Tor with a controller watching for low-severity log messages.
      Bugfix on 0.1.0.2-rc. Fixes bug 2190.
    - Add a check for SIZE_T_MAX to tor_realloc() to try to avoid
      underflow errors there too. Fixes the other part of bug 2324.
    - Fix a bug where we would assert if we ever had a
      cached-descriptors.new file (or another file read directly into
      memory) of exactly SIZE_T_CEILING bytes. Fixes bug 2326; bugfix
      on 0.2.1.25. Found by doorss.
    - Fix some potential asserts and parsing issues with grossly
      malformed router caches. Fixes bug 2352; bugfix on Tor 0.2.1.27.
      Found by doorss.

  o Minor bugfixes (other):
    - Fix a bug with handling misformed replies to reverse DNS lookup
      requests in DNSPort. Bugfix on Tor 0.2.0.1-alpha. Related to a
      bug reported by doorss.
    - Fix compilation on mingw when a pthreads compatibility library
      has been installed. (We don't want to use it, so we shouldn't
      be including pthread.h.) Fixes bug 2313; bugfix on 0.1.0.1-rc.
    - Fix a bug where we would declare that we had run out of virtual
      addresses when the address space was only half-exhausted. Bugfix
      on 0.1.2.1-alpha.
    - Correctly handle the case where AutomapHostsOnResolve is set but
      no virtual addresses are available. Fixes bug 2328; bugfix on
      0.1.2.1-alpha. Bug found by doorss.
    - Correctly handle wrapping around to when we run out of virtual
      address space. Found by cypherpunks, bugfix on 0.2.0.5-alpha.
    - The 0.2.1.28 tarball was missing src/common/OpenBSD_malloc_Linux.c
      because we built it with a too-old version of automake. Thus that
      release broke ./configure --enable-openbsd-malloc, which is popular
      among really fast exit relays on Linux.

  o Minor features:
    - Update to the January 1 2011 Maxmind GeoLite Country database.
    - Introduce output size checks on all of our decryption functions.

  o Build changes:
    - Tor does not build packages correctly with Automake 1.6 and earlier;
      added a check to Makefile.am to make sure that we're building with
      Automake 1.7 or later.


Changes in version 0.2.2.20-alpha - 2010-12-17
  Tor 0.2.2.20-alpha does some code cleanup to reduce the risk of remotely
  exploitable bugs. We also fix a variety of other significant bugs,
  change the IP address for one of our directory authorities, and update
  the minimum version that Tor relays must run to join the network.

  o Major bugfixes:
    - Fix a remotely exploitable bug that could be used to crash instances
      of Tor remotely by overflowing on the heap. Remote-code execution
      hasn't been confirmed, but can't be ruled out. Everyone should
      upgrade. Bugfix on the 0.1.1 series and later.
    - Fix a bug that could break accounting on 64-bit systems with large
      time_t values, making them hibernate for impossibly long intervals.
      Fixes bug 2146. Bugfix on 0.0.9pre6; fix by boboper.
    - Fix a logic error in directory_fetches_from_authorities() that
      would cause all _non_-exits refusing single-hop-like circuits
      to fetch from authorities, when we wanted to have _exits_ fetch
      from authorities. Fixes more of 2097. Bugfix on 0.2.2.16-alpha;
      fix by boboper.
    - Fix a stream fairness bug that would cause newer streams on a given
      circuit to get preference when reading bytes from the origin or
      destination. Fixes bug 2210. Fix by Mashael AlSabah. This bug was
      introduced before the first Tor release, in svn revision r152.

  o Directory authority changes:
    - Change IP address and ports for gabelmoo (v3 directory authority).

  o Minor bugfixes:
    - Avoid crashes when AccountingMax is set on clients. Fixes bug 2235.
      Bugfix on 0.2.2.18-alpha. Diagnosed by boboper.
    - Fix an off-by-one error in calculating some controller command
      argument lengths. Fortunately, this mistake is harmless since
      the controller code does redundant NUL termination too. Found by
      boboper. Bugfix on 0.1.1.1-alpha.
    - Do not dereference NULL if a bridge fails to build its
      extra-info descriptor. Found by an anonymous commenter on
      Trac. Bugfix on 0.2.2.19-alpha.

  o Minor features:
    - Update to the December 1 2010 Maxmind GeoLite Country database.
    - Directory authorities now reject relays running any versions of
      Tor between 0.2.1.3-alpha and 0.2.1.18 inclusive; they have
      known bugs that keep RELAY_EARLY cells from working on rendezvous
      circuits. Followup to fix for bug 2081.
    - Directory authorities now reject relays running any version of Tor
      older than 0.2.0.26-rc. That version is the earliest that fetches
      current directory information correctly. Fixes bug 2156.
    - Report only the top 10 ports in exit-port stats in order not to
      exceed the maximum extra-info descriptor length of 50 KB. Implements
      task 2196.


Changes in version 0.2.1.28 - 2010-12-17
  Tor 0.2.1.28 does some code cleanup to reduce the risk of remotely
  exploitable bugs. We also took this opportunity to change the IP address
  for one of our directory authorities, and to update the geoip database
  we ship.

  o Major bugfixes:
    - Fix a remotely exploitable bug that could be used to crash instances
      of Tor remotely by overflowing on the heap. Remote-code execution
      hasn't been confirmed, but can't be ruled out. Everyone should
      upgrade. Bugfix on the 0.1.1 series and later.

  o Directory authority changes:
    - Change IP address and ports for gabelmoo (v3 directory authority).

  o Minor features:
    - Update to the December 1 2010 Maxmind GeoLite Country database.


Changes in version 0.2.1.27 - 2010-11-23
  Yet another OpenSSL security patch broke its compatibility with Tor:
  Tor 0.2.1.27 makes relays work with openssl 0.9.8p and 1.0.0.b. We
  also took this opportunity to fix several crash bugs, integrate a new
  directory authority, and update the bundled GeoIP database.

  o Major bugfixes:
    - Resolve an incompatibility with OpenSSL 0.9.8p and OpenSSL 1.0.0b:
      No longer set the tlsext_host_name extension on server SSL objects;
      but continue to set it on client SSL objects. Our goal in setting
      it was to imitate a browser, not a vhosting server. Fixes bug 2204;
      bugfix on 0.2.1.1-alpha.
    - Do not log messages to the controller while shrinking buffer
      freelists. Doing so would sometimes make the controller connection
      try to allocate a buffer chunk, which would mess up the internals
      of the freelist and cause an assertion failure. Fixes bug 1125;
      fixed by Robert Ransom. Bugfix on 0.2.0.16-alpha.
    - Learn our external IP address when we're a relay or bridge, even if
      we set PublishServerDescriptor to 0. Bugfix on 0.2.0.3-alpha,
      where we introduced bridge relays that don't need to publish to
      be useful. Fixes bug 2050.
    - Do even more to reject (and not just ignore) annotations on
      router descriptors received anywhere but from the cache. Previously
      we would ignore such annotations at first, but cache them to disk
      anyway. Bugfix on 0.2.0.8-alpha. Found by piebeer.
    - When you're using bridges and your network goes away and your
      bridges get marked as down, recover when you attempt a new socks
      connection (if the network is back), rather than waiting up to an
      hour to try fetching new descriptors for your bridges. Bugfix on
      0.2.0.3-alpha; fixes bug 1981.

  o Major features:
    - Move to the November 2010 Maxmind GeoLite country db (rather
      than the June 2009 ip-to-country GeoIP db) for our statistics that
      count how many users relays are seeing from each country. Now we'll
      have more accurate data, especially for many African countries.

  o New directory authorities:
    - Set up maatuska (run by Linus Nordberg) as the eighth v3 directory
      authority.

  o Minor bugfixes:
    - Fix an assertion failure that could occur in directory caches or
      bridge users when using a very short voting interval on a testing
      network. Diagnosed by Robert Hogan. Fixes bug 1141; bugfix on
      0.2.0.8-alpha.
    - Enforce multiplicity rules when parsing annotations. Bugfix on
      0.2.0.8-alpha. Found by piebeer.
    - Allow handshaking OR connections to take a full KeepalivePeriod
      seconds to handshake. Previously, we would close them after
      IDLE_OR_CONN_TIMEOUT (180) seconds, the same timeout as if they
      were open. Bugfix on 0.2.1.26; fixes bug 1840. Thanks to mingw-san
      for analysis help.
    - When building with --enable-gcc-warnings on OpenBSD, disable
      warnings in system headers. This makes --enable-gcc-warnings
      pass on OpenBSD 4.8.

  o Minor features:
    - Exit nodes didn't recognize EHOSTUNREACH as a plausible error code,
      and so sent back END_STREAM_REASON_MISC. Clients now recognize a new
      stream ending reason for this case: END_STREAM_REASON_NOROUTE.
      Servers can start sending this code when enough clients recognize
      it. Bugfix on 0.1.0.1-rc; fixes part of bug 1793.
    - Build correctly on mingw with more recent versions of OpenSSL 0.9.8.
      Patch from mingw-san.

  o Removed files:
    - Remove the old debian/ directory from the main Tor distribution.
      The official Tor-for-debian git repository lives at the URL
      https://git.torproject.org/debian/tor.git
    - Stop shipping the old doc/website/ directory in the tarball. We
      changed the website format in late 2010, and what we shipped in
      0.2.1.26 really wasn't that useful anyway.


Changes in version 0.2.2.19-alpha - 2010-11-22
  Yet another OpenSSL security patch broke its compatibility with Tor:
  Tor 0.2.2.19-alpha makes relays work with OpenSSL 0.9.8p and 1.0.0.b.

  o Major bugfixes:
    - Resolve an incompatibility with OpenSSL 0.9.8p and OpenSSL 1.0.0b:
      No longer set the tlsext_host_name extension on server SSL objects;
      but continue to set it on client SSL objects. Our goal in setting
      it was to imitate a browser, not a vhosting server. Fixes bug 2204;
      bugfix on 0.2.1.1-alpha.

  o Minor bugfixes:
    - Try harder not to exceed the maximum length of 50 KB when writing
      statistics to extra-info descriptors. This bug was triggered by very
      fast relays reporting exit-port, entry, and dirreq statistics.
      Reported by Olaf Selke. Bugfix on 0.2.2.1-alpha. Fixes bug 2183.
    - Publish a router descriptor even if generating an extra-info
      descriptor fails. Previously we would not publish a router
      descriptor without an extra-info descriptor; this can cause fast
      exit relays collecting exit-port statistics to drop from the
      consensus. Bugfix on 0.1.2.9-rc; fixes bug 2195.


Changes in version 0.2.2.18-alpha - 2010-11-16
  Tor 0.2.2.18-alpha fixes several crash bugs that have been nagging
  us lately, makes unpublished bridge relays able to detect their IP
  address, and fixes a wide variety of other bugs to get us much closer
  to a stable release.

  o Major bugfixes:
    - Do even more to reject (and not just ignore) annotations on
      router descriptors received anywhere but from the cache. Previously
      we would ignore such annotations at first, but cache them to disk
      anyway. Bugfix on 0.2.0.8-alpha. Found by piebeer.
    - Do not log messages to the controller while shrinking buffer
      freelists. Doing so would sometimes make the controller connection
      try to allocate a buffer chunk, which would mess up the internals
      of the freelist and cause an assertion failure. Fixes bug 1125;
      fixed by Robert Ransom. Bugfix on 0.2.0.16-alpha.
    - Learn our external IP address when we're a relay or bridge, even if
      we set PublishServerDescriptor to 0. Bugfix on 0.2.0.3-alpha,
      where we introduced bridge relays that don't need to publish to
      be useful. Fixes bug 2050.
    - Maintain separate TLS contexts and certificates for incoming and
      outgoing connections in bridge relays. Previously we would use the
      same TLS contexts and certs for incoming and outgoing connections.
      Bugfix on 0.2.0.3-alpha; addresses bug 988.
    - Maintain separate identity keys for incoming and outgoing TLS
      contexts in bridge relays. Previously we would use the same
      identity keys for incoming and outgoing TLS contexts. Bugfix on
      0.2.0.3-alpha; addresses the other half of bug 988.
    - Avoid an assertion failure when we as an authority receive a
      duplicate upload of a router descriptor that we already have,
      but which we previously considered an obsolete descriptor.
      Fixes another case of bug 1776. Bugfix on 0.2.2.16-alpha.
    - Avoid a crash bug triggered by looking at a dangling pointer while
      setting the network status consensus. Found by Robert Ransom.
      Bugfix on 0.2.2.17-alpha. Fixes bug 2097.
    - Fix a logic error where servers that _didn't_ act as exits would
      try to keep their server lists more aggressively up to date than
      exits, when it was supposed to be the other way around. Bugfix
      on 0.2.2.17-alpha.

  o Minor bugfixes (on Tor 0.2.1.x and earlier):
    - When we're trying to guess whether we know our IP address as
      a relay, we would log various ways that we failed to guess
      our address, but never log that we ended up guessing it
      successfully. Now add a log line to help confused and anxious
      relay operators. Bugfix on 0.1.2.1-alpha; fixes bug 1534.
    - Bring the logic that gathers routerinfos and assesses the
      acceptability of circuits into line. This prevents a Tor OP from
      getting locked in a cycle of choosing its local OR as an exit for a
      path (due to a .exit request) and then rejecting the circuit because
      its OR is not listed yet. It also prevents Tor clients from using an
      OR running in the same instance as an exit (due to a .exit request)
      if the OR does not meet the same requirements expected of an OR
      running elsewhere. Fixes bug 1859; bugfix on 0.1.0.1-rc.
    - Correctly describe errors that occur when generating a TLS object.
      Previously we would attribute them to a failure while generating a
      TLS context. Patch by Robert Ransom. Bugfix on 0.1.0.4-rc; fixes
      bug 1994.
    - Enforce multiplicity rules when parsing annotations. Bugfix on
      0.2.0.8-alpha. Found by piebeer.
    - Fix warnings that newer versions of autoconf produced during
      ./autogen.sh. These warnings appear to be harmless in our case,
      but they were extremely verbose. Fixes bug 2020.

  o Minor bugfixes (on Tor 0.2.2.x):
    - Enable protection of small arrays whenever we build with gcc
      hardening features, not only when also building with warnings
      enabled. Fixes bug 2031; bugfix on 0.2.2.14-alpha. Reported by keb.

  o Minor features:
    - Make hidden services work better in private Tor networks by not
      requiring any uptime to join the hidden service descriptor
      DHT. Implements ticket 2088.
    - Rate-limit the "your application is giving Tor only an IP address"
      warning. Addresses bug 2000; bugfix on 0.0.8pre2.
    - When AllowSingleHopExits is set, print a warning to explain to the
      relay operator why most clients are avoiding her relay.
    - Update to the November 1 2010 Maxmind GeoLite Country database.

  o Code simplifications and refactoring:
    - When we fixed bug 1038 we had to put in a restriction not to send
      RELAY_EARLY cells on rend circuits. This was necessary as long
      as relays using Tor 0.2.1.3-alpha through 0.2.1.18-alpha were
      active. Now remove this obsolete check. Resolves bug 2081.
    - Some options used different conventions for uppercasing of acronyms
      when comparing manpage and source. Fix those in favor of the
      manpage, as it makes sense to capitalize acronyms.
    - Remove the torrc.complete file. It hasn't been kept up to date
      and users will have better luck checking out the manpage.
    - Remove the obsolete "NoPublish" option; it has been flagged
      as obsolete and has produced a warning since 0.1.1.18-rc.
    - Remove everything related to building the expert bundle for OS X.
      It has confused many users, doesn't work right on OS X 10.6,
      and is hard to get rid of once installed. Resolves bug 1274.


Changes in version 0.2.2.17-alpha - 2010-09-30
  Tor 0.2.2.17-alpha introduces a feature to make it harder for clients
  to use one-hop circuits (which can put the exit relays at higher risk,
  plus unbalance the network); fixes a big bug in bandwidth accounting
  for relays that want to limit their monthly bandwidth use; fixes a
  big pile of bugs in how clients tolerate temporary network failure;
  and makes our adaptive circuit build timeout feature (which improves
  client performance if your network is fast while not breaking things
  if your network is slow) better handle bad networks.

  o Major features:
    - Exit relays now try harder to block exit attempts from unknown
      relays, to make it harder for people to use them as one-hop proxies
      a la tortunnel. Controlled by the refuseunknownexits consensus
      parameter (currently enabled), or you can override it on your
      relay with the RefuseUnknownExits torrc option. Resolves bug 1751.

  o Major bugfixes (0.2.1.x and earlier):
    - Fix a bug in bandwidth accounting that could make us use twice
      the intended bandwidth when our interval start changes due to
      daylight saving time. Now we tolerate skew in stored vs computed
      interval starts: if the start of the period changes by no more than
      50% of the period's duration, we remember bytes that we transferred
      in the old period. Fixes bug 1511; bugfix on 0.0.9pre5.
    - Always search the Windows system directory for system DLLs, and
      nowhere else. Bugfix on 0.1.1.23; fixes bug 1954.
    - When you're using bridges and your network goes away and your
      bridges get marked as down, recover when you attempt a new socks
      connection (if the network is back), rather than waiting up to an
      hour to try fetching new descriptors for your bridges. Bugfix on
      0.2.0.3-alpha; fixes bug 1981.

  o Major bugfixes (on 0.2.2.x):
    - Fix compilation on Windows. Bugfix on 0.2.2.16-alpha; related to
      bug 1797.
    - Fix a segfault that could happen when operating a bridge relay with
      no GeoIP database set. Fixes bug 1964; bugfix on 0.2.2.15-alpha.
    - The consensus bandwidth-weights (used by clients to choose fast
      relays) entered an unexpected edge case in September where
      Exits were much scarcer than Guards, resulting in bad weight
      recommendations. Now we compute them using new constraints that
      should succeed in all cases. Also alter directory authorities to
      not include the bandwidth-weights line if they fail to produce
      valid values. Fixes bug 1952; bugfix on 0.2.2.10-alpha.
    - When weighting bridges during path selection, we used to trust
      the bandwidths they provided in their descriptor, only capping them
      at 10MB/s. This turned out to be problematic for two reasons:
      Bridges could claim to handle a lot more traffic then they
      actually would, thus making more clients pick them and have a
      pretty effective DoS attack. The other issue is that new bridges
      that might not have a good estimate for their bw capacity yet
      would not get used at all unless no other bridges are available
      to a client. Fixes bug 1912; bugfix on 0.2.2.7-alpha.

  o Major bugfixes (on the circuit build timeout feature, 0.2.2.x):
    - Ignore cannibalized circuits when recording circuit build times.
      This should provide for a minor performance improvement for hidden
      service users using 0.2.2.14-alpha, and should remove two spurious
      notice log messages. Bugfix on 0.2.2.14-alpha; fixes bug 1740.
    - Simplify the logic that causes us to decide if the network is
      unavailable for purposes of recording circuit build times. If we
      receive no cells whatsoever for the entire duration of a circuit's
      full measured lifetime, the network is probably down. Also ignore
      one-hop directory fetching circuit timeouts when calculating our
      circuit build times. These changes should hopefully reduce the
      cases where we see ridiculous circuit build timeouts for people
      with spotty wireless connections. Fixes part of bug 1772; bugfix
      on 0.2.2.2-alpha.
    - Prevent the circuit build timeout from becoming larger than
      the maximum build time we have ever seen. Also, prevent the time
      period for measurement circuits from becoming larger than twice that
      value. Fixes the other part of bug 1772; bugfix on 0.2.2.2-alpha.

  o Minor features:
    - When we run out of directory information such that we can't build
      circuits, but then get enough that we can build circuits, log when
      we actually construct a circuit, so the user has a better chance of
      knowing what's going on. Fixes bug 1362.
    - Be more generous with how much bandwidth we'd use up (with
      accounting enabled) before entering "soft hibernation". Previously,
      we'd refuse new connections and circuits once we'd used up 95% of
      our allotment. Now, we use up 95% of our allotment, AND make sure
      that we have no more than 500MB (or 3 hours of expected traffic,
      whichever is lower) remaining before we enter soft hibernation.
    - If we've configured EntryNodes and our network goes away and/or all
      our entrynodes get marked down, optimistically retry them all when
      a new socks application request appears. Fixes bug 1882.
    - Add some more defensive programming for architectures that can't
      handle unaligned integer accesses. We don't know of any actual bugs
      right now, but that's the best time to fix them. Fixes bug 1943.
    - Support line continuations in the torrc config file. If a line
      ends with a single backslash character, the newline is ignored, and
      the configuration value is treated as continuing on the next line.
      Resolves bug 1929.

  o Minor bugfixes (on 0.2.1.x and earlier):
    - For bandwidth accounting, calculate our expected bandwidth rate
      based on the time during which we were active and not in
      soft-hibernation during the last interval. Previously, we were
      also considering the time spent in soft-hibernation. If this
      was a long time, we would wind up underestimating our bandwidth
      by a lot, and skewing our wakeup time towards the start of the
      accounting interval. Fixes bug 1789. Bugfix on 0.0.9pre5.

  o Minor bugfixes (on 0.2.2.x):
    - Resume generating CIRC FAILED REASON=TIMEOUT control port messages,
      which were disabled by the circuit build timeout changes in
      0.2.2.14-alpha. Bugfix on 0.2.2.14-alpha; fixes bug 1739.
    - Make sure we don't warn about missing bandwidth weights when
      choosing bridges or other relays not in the consensus. Bugfix on
      0.2.2.10-alpha; fixes bug 1805.
    - In our logs, do not double-report signatures from unrecognized
      authorities both as "from unknown authority" and "not
      present". Fixes bug 1956, bugfix on 0.2.2.16-alpha.


Changes in version 0.2.2.16-alpha - 2010-09-17
  Tor 0.2.2.16-alpha fixes a variety of old stream fairness bugs (most
  evident at exit relays), and also continues to resolve all the little
  bugs that have been filling up trac lately.

  o Major bugfixes (stream-level fairness):
    - When receiving a circuit-level SENDME for a blocked circuit, try
      to package cells fairly from all the streams that had previously
      been blocked on that circuit. Previously, we had started with the
      oldest stream, and allowed each stream to potentially exhaust
      the circuit's package window. This gave older streams on any
      given circuit priority over newer ones. Fixes bug 1937. Detected
      originally by Camilo Viecco. This bug was introduced before the
      first Tor release, in svn commit r152: it is the new winner of
      the longest-lived bug prize.
    - When the exit relay got a circuit-level sendme cell, it started
      reading on the exit streams, even if had 500 cells queued in the
      circuit queue already, so the circuit queue just grew and grew in
      some cases. We fix this by not re-enabling reading on receipt of a
      sendme cell when the cell queue is blocked. Fixes bug 1653. Bugfix
      on 0.2.0.1-alpha. Detected by Mashael AlSabah. Original patch by
      "yetonetime".
    - Newly created streams were allowed to read cells onto circuits,
      even if the circuit's cell queue was blocked and waiting to drain.
      This created potential unfairness, as older streams would be
      blocked, but newer streams would gladly fill the queue completely.
      We add code to detect this situation and prevent any stream from
      getting more than one free cell. Bugfix on 0.2.0.1-alpha. Partially
      fixes bug 1298.

  o Minor features:
    - Update to the September 1 2010 Maxmind GeoLite Country database.
    - Warn when CookieAuthFileGroupReadable is set but CookieAuthFile is
      not. This would lead to a cookie that is still not group readable.
      Closes bug 1843. Suggested by katmagic.
    - When logging a rate-limited warning, we now mention how many messages
      got suppressed since the last warning.
    - Add new "perconnbwrate" and "perconnbwburst" consensus params to
      do individual connection-level rate limiting of clients. The torrc
      config options with the same names trump the consensus params, if
      both are present. Replaces the old "bwconnrate" and "bwconnburst"
      consensus params which were broken from 0.2.2.7-alpha through
      0.2.2.14-alpha. Closes bug 1947.
    - When a router changes IP address or port, authorities now launch
      a new reachability test for it. Implements ticket 1899.
    - Make the formerly ugly "2 unknown, 7 missing key, 0 good, 0 bad,
      2 no signature, 4 required" messages about consensus signatures
      easier to read, and make sure they get logged at the same severity
      as the messages explaining which keys are which. Fixes bug 1290.
    - Don't warn when we have a consensus that we can't verify because
      of missing certificates, unless those certificates are ones
      that we have been trying and failing to download. Fixes bug 1145.
    - If you configure your bridge with a known identity fingerprint,
      and the bridge authority is unreachable (as it is in at least
      one country now), fall back to directly requesting the descriptor
      from the bridge. Finishes the feature started in 0.2.0.10-alpha;
      closes bug 1138.
    - When building with --enable-gcc-warnings on OpenBSD, disable
      warnings in system headers. This makes --enable-gcc-warnings
      pass on OpenBSD 4.8.

  o Minor bugfixes (on 0.2.1.x and earlier):
    - Authorities will now attempt to download consensuses if their
      own efforts to make a live consensus have failed. This change
      means authorities that restart will fetch a valid consensus, and
      it means authorities that didn't agree with the current consensus
      will still fetch and serve it if it has enough signatures. Bugfix
      on 0.2.0.9-alpha; fixes bug 1300.
    - Ensure DNS requests launched by "RESOLVE" commands from the
      controller respect the __LeaveStreamsUnattached setconf options. The
      same goes for requests launched via DNSPort or transparent
      proxying. Bugfix on 0.2.0.1-alpha; fixes bug 1525.
    - Allow handshaking OR connections to take a full KeepalivePeriod
      seconds to handshake. Previously, we would close them after
      IDLE_OR_CONN_TIMEOUT (180) seconds, the same timeout as if they
      were open. Bugfix on 0.2.1.26; fixes bug 1840. Thanks to mingw-san
      for analysis help.
    - Rate-limit "Failed to hand off onionskin" warnings.
    - Never relay a cell for a circuit we have already destroyed.
      Between marking a circuit as closeable and finally closing it,
      it may have been possible for a few queued cells to get relayed,
      even though they would have been immediately dropped by the next
      OR in the circuit. Fixes bug 1184; bugfix on 0.2.0.1-alpha.
    - Never queue a cell for a circuit that's already been marked
      for close.
    - Never vote for a server as "Running" if we have a descriptor for
      it claiming to be hibernating, and that descriptor was published
      more recently than our last contact with the server. Bugfix on
      0.2.0.3-alpha; fixes bug 911.
    - Squash a compile warning on OpenBSD. Reported by Tas; fixes
      bug 1848.

  o Minor bugfixes (on 0.2.2.x):
    - Fix a regression introduced in 0.2.2.7-alpha that marked relays
      down if a directory fetch fails and you've configured either
      bridges or EntryNodes. The intent was to mark the relay as down
      _unless_ you're using bridges or EntryNodes, since if you are
      then you could quickly run out of entry points.
    - Fix the Windows directory-listing code. A bug introduced in
      0.2.2.14-alpha could make Windows directory servers forget to load
      some of their cached v2 networkstatus files.
    - Really allow clients to use relays as bridges. Fixes bug 1776;
      bugfix on 0.2.2.15-alpha.
    - Demote a warn to info that happens when the CellStatistics option
      was just enabled. Bugfix on 0.2.2.15-alpha; fixes bug 1921.
      Reported by Moritz Bartl.
    - On Windows, build correctly either with or without Unicode support.
      This is necessary so that Tor can support fringe platforms like
      Windows 98 (which has no Unicode), or Windows CE (which has no
      non-Unicode). Bugfix on 0.2.2.14-alpha; fixes bug 1797.

  o Testing
    - Add a unit test for cross-platform directory-listing code.


Changes in version 0.2.2.15-alpha - 2010-08-18
  Tor 0.2.2.15-alpha fixes a big bug in hidden service availability,
  fixes a variety of other bugs that were preventing performance
  experiments from moving forward, fixes several bothersome memory leaks,
  and generally closes a lot of smaller bugs that have been filling up
  trac lately.

  o Major bugfixes:
    - Stop assigning the HSDir flag to relays that disable their
      DirPort (and thus will refuse to answer directory requests). This
      fix should dramatically improve the reachability of hidden services:
      hidden services and hidden service clients pick six HSDir relays
      to store and retrieve the hidden service descriptor, and currently
      about half of the HSDir relays will refuse to work. Bugfix on
      0.2.0.10-alpha; fixes part of bug 1693.
    - The PerConnBWRate and Burst config options, along with the
      bwconnrate and bwconnburst consensus params, initialized each conn's
      token bucket values only when the connection is established. Now we
      update them if the config options change, and update them every time
      we get a new consensus. Otherwise we can encounter an ugly edge
      case where we initialize an OR conn to client-level bandwidth,
      but then later the relay joins the consensus and we leave it
      throttled. Bugfix on 0.2.2.7-alpha; fixes bug 1830.
    - Fix a regression that caused Tor to rebind its ports if it receives
      SIGHUP while hibernating. Bugfix in 0.1.1.6-alpha; closes bug 919.

  o Major features:
    - Lower the maximum weighted-fractional-uptime cutoff to 98%. This
      should give us approximately 40-50% more Guard-flagged nodes,
      improving the anonymity the Tor network can provide and also
      decreasing the dropoff in throughput that relays experience when
      they first get the Guard flag.
    - Allow enabling or disabling the *Statistics config options while
      Tor is running.

  o Minor features:
    - Update to the August 1 2010 Maxmind GeoLite Country database.
    - Have the controller interface give a more useful message than
      "Internal Error" in response to failed GETINFO requests.
    - Warn when the same option is provided more than once in a torrc
      file, on the command line, or in a single SETCONF statement, and
      the option is one that only accepts a single line. Closes bug 1384.
    - Build correctly on mingw with more recent versions of OpenSSL 0.9.8.
      Patch from mingw-san.
    - Add support for the country code "{??}" in torrc options like
      ExcludeNodes, to indicate all routers of unknown country. Closes
      bug 1094.
    - Relays report the number of bytes spent on answering directory
      requests in extra-info descriptors similar to {read,write}-history.
      Implements enhancement 1790.

  o Minor bugfixes (on 0.2.1.x and earlier):
    - Complain if PublishServerDescriptor is given multiple arguments that
      include 0 or 1. This configuration will be rejected in the future.
      Bugfix on 0.2.0.1-alpha; closes bug 1107.
    - Disallow BridgeRelay 1 and ORPort 0 at once in the configuration.
      Bugfix on 0.2.0.13-alpha; closes bug 928.
    - Change "Application request when we're believed to be offline."
      notice to "Application request when we haven't used client
      functionality lately.", to clarify that it's not an error. Bugfix
      on 0.0.9.3; fixes bug 1222.
    - Fix a bug in the controller interface where "GETINFO ns/asdaskljkl"
      would return "551 Internal error" rather than "552 Unrecognized key
      ns/asdaskljkl". Bugfix on 0.1.2.3-alpha.
    - Users can't configure a regular relay to be their bridge. It didn't
      work because when Tor fetched the bridge descriptor, it found
      that it already had it, and didn't realize that the purpose of the
      descriptor had changed. Now we replace routers with a purpose other
      than bridge with bridge descriptors when fetching them. Bugfix on
      0.1.1.9-alpha. Bug 1776 not yet fixed because now we immediately
      refetch the descriptor with router purpose 'general', disabling
      it as a bridge.
    - Fix a rare bug in rend_fn unit tests: we would fail a test when
      a randomly generated port is 0. Diagnosed by Matt Edman. Bugfix
      on 0.2.0.10-alpha; fixes bug 1808.
    - Exit nodes didn't recognize EHOSTUNREACH as a plausible error code,
      and so sent back END_STREAM_REASON_MISC. Clients now recognize a new
      stream ending reason for this case: END_STREAM_REASON_NOROUTE.
      Servers can start sending this code when enough clients recognize
      it. Also update the spec to reflect this new reason. Bugfix on
      0.1.0.1-rc; fixes part of bug 1793.
    - Delay geoip stats collection by bridges for 6 hours, not 2 hours,
      when we switch from being a public relay to a bridge. Otherwise
      there will still be clients that see the relay in their consensus,
      and the stats will end up wrong. Bugfix on 0.2.1.15-rc; fixes bug
      932 even more.
    - Instead of giving an assertion failure on an internal mismatch
      on estimated freelist size, just log a BUG warning and try later.
      Mitigates but does not fix bug 1125.
    - Fix an assertion failure that could occur in caches or bridge users
      when using a very short voting interval on a testing network.
      Diagnosed by Robert Hogan. Fixes bug 1141; bugfix on 0.2.0.8-alpha.

  o Minor bugfixes (on 0.2.2.x):
    - Alter directory authorities to always consider Exit-flagged nodes
      as potential Guard nodes in their votes. The actual decision to
      use Exits as Guards is done in the consensus bandwidth weights.
      Fixes bug 1294; bugfix on 0.2.2.10-alpha.
    - When the controller is reporting the purpose of circuits that
      didn't finish building before the circuit build timeout, it was
      printing UNKNOWN_13. Now print EXPIRED. Bugfix on 0.2.2.14-alpha.
    - Our libevent version parsing code couldn't handle versions like
      1.4.14b-stable and incorrectly warned the user about using an
      old and broken version of libevent. Treat 1.4.14b-stable like
      1.4.14-stable when parsing the version. Fixes bug 1731; bugfix
      on 0.2.2.1-alpha.
    - Don't use substitution references like $(VAR:MOD) when
      $(asciidoc_files) is empty -- make(1) on NetBSD transforms
      '$(:x)' to 'x' rather than the empty string. This bites us in
      doc/ when configured with --disable-asciidoc. Bugfix on
      0.2.2.9-alpha; fixes bug 1773.
    - Remove a spurious hidden service server-side log notice about
      "Ancient non-dirty circuits". Bugfix on 0.2.2.14-alpha; fixes
      bug 1741.
    - Fix compilation with --with-dmalloc set. Bugfix on 0.2.2.6-alpha;
      fixes bug 1832.
    - Correctly report written bytes on linked connections. Found while
      implementing 1790. Bugfix on 0.2.2.4-alpha.
    - Fix three memory leaks: one in circuit_build_times_parse_state(),
      one in dirvote_add_signatures_to_pending_consensus(), and one every
      time we parse a v3 network consensus. Bugfixes on 0.2.2.14-alpha,
      0.2.2.6-alpha, and 0.2.2.10-alpha respectively; fixes bug 1831.

  o Code simplifications and refactoring:
    - Take a first step towards making or.h smaller by splitting out
      function definitions for all source files in src/or/. Leave
      structures and defines in or.h for now.
    - Remove a bunch of unused function declarations as well as a block of
      #if 0'd code from the unit tests. Closes bug 1824.
    - New unit tests for exit-port history statistics; refactored exit
      statistics code to be more easily tested.
    - Remove the old debian/ directory from the main Tor distribution.
      The official Tor-for-debian git repository lives at the URL
      https://git.torproject.org/debian/tor.git


Changes in version 0.2.2.14-alpha - 2010-07-12
  Tor 0.2.2.14-alpha greatly improves client-side handling of
  circuit build timeouts, which are used to estimate speed and improve
  performance. We also move to a much better GeoIP database, port Tor to
  Windows CE, introduce new compile flags that improve code security,
  add an eighth v3 directory authority, and address a lot of more
  minor issues.

  o Major bugfixes:
    - Tor directory authorities no longer crash when started with a
      cached-microdesc-consensus file in their data directory. Bugfix
      on 0.2.2.6-alpha; fixes bug 1532.
    - Treat an unset $HOME like an empty $HOME rather than triggering an
      assert. Bugfix on 0.0.8pre1; fixes bug 1522.
    - Ignore negative and large circuit build timeout values that can
      happen during a suspend or hibernate. These values caused various
      asserts to fire. Bugfix on 0.2.2.2-alpha; fixes bug 1245.
    - Alter calculation of Pareto distribution parameter 'Xm' for
      Circuit Build Timeout learning to use the weighted average of the
      top N=3 modes (because we have three entry guards). Considering
      multiple modes should improve the timeout calculation in some cases,
      and prevent extremely high timeout values. Bugfix on 0.2.2.2-alpha;
      fixes bug 1335.
    - Alter calculation of Pareto distribution parameter 'Alpha' to use a
      right censored distribution model. This approach improves over the
      synthetic timeout generation approach that was producing insanely
      high timeout values. Now we calculate build timeouts using truncated
      times. Bugfix on 0.2.2.2-alpha; fixes bugs 1245 and 1335.
    - Do not close circuits that are under construction when they reach
      the circuit build timeout. Instead, leave them building (but do not
      use them) for up until the time corresponding to the 95th percentile
      on the Pareto CDF or 60 seconds, whichever is greater. This is done
      to provide better data for the new Pareto model. This percentile
      can be controlled by the consensus.

  o Major features:
    - Move to the June 2010 Maxmind GeoLite country db (rather than the
      June 2009 ip-to-country GeoIP db) for our statistics that count
      how many users relays are seeing from each country. Now we have
      more accurate data for many African countries.
    - Port Tor to build and run correctly on Windows CE systems, using
      the wcecompat library. Contributed by Valerio Lupi.
    - New "--enable-gcc-hardening" ./configure flag (off by default)
      to turn on gcc compile time hardening options. It ensures
      that signed ints have defined behavior (-fwrapv), enables
      -D_FORTIFY_SOURCE=2 (requiring -O2), adds stack smashing protection
      with canaries (-fstack-protector-all), turns on ASLR protection if
      supported by the kernel (-fPIE, -pie), and adds additional security
      related warnings. Verified to work on Mac OS X and Debian Lenny.
    - New "--enable-linker-hardening" ./configure flag (off by default)
      to turn on ELF specific hardening features (relro, now). This does
      not work with Mac OS X or any other non-ELF binary format.

  o New directory authorities:
    - Set up maatuska (run by Linus Nordberg) as the eighth v3 directory
      authority.

  o Minor features:
    - New config option "WarnUnsafeSocks 0" disables the warning that
      occurs whenever Tor receives a socks handshake using a version of
      the socks protocol that can only provide an IP address (rather
      than a hostname). Setups that do DNS locally over Tor are fine,
      and we shouldn't spam the logs in that case.
    - Convert the HACKING file to asciidoc, and add a few new sections
      to it, explaining how we use Git, how we make changelogs, and
      what should go in a patch.
    - Add a TIMEOUT_RATE keyword to the BUILDTIMEOUT_SET control port
      event, to give information on the current rate of circuit timeouts
      over our stored history.
    - Add ability to disable circuit build time learning via consensus
      parameter and via a LearnCircuitBuildTimeout config option. Also
      automatically disable circuit build time calculation if we are
      either a AuthoritativeDirectory, or if we fail to write our state
      file. Fixes bug 1296.
    - More gracefully handle corrupt state files, removing asserts
      in favor of saving a backup and resetting state.
    - Rename the "log.h" header to "torlog.h" so as to conflict with fewer
      system headers.

  o Minor bugfixes:
    - Build correctly on OSX with zlib 1.2.4 and higher with all warnings
      enabled.
    - When a2x fails, mention that the user could disable manpages instead
      of trying to fix their asciidoc installation.
    - Where available, use Libevent 2.0's periodic timers so that our
      once-per-second cleanup code gets called even more closely to
      once per second than it would otherwise. Fixes bug 943.
    - If you run a bridge that listens on multiple IP addresses, and
      some user configures a bridge address that uses a different IP
      address than your bridge writes in its router descriptor, and the
      user doesn't specify an identity key, their Tor would discard the
      descriptor because "it isn't one of our configured bridges", and
      fail to bootstrap. Now believe the descriptor and bootstrap anyway.
      Bugfix on 0.2.0.3-alpha.
    - If OpenSSL fails to make a duplicate of a private or public key, log
      an error message and try to exit cleanly. May help with debugging
      if bug 1209 ever remanifests.
    - Save a couple bytes in memory allocation every time we escape
      certain characters in a string. Patch from Florian Zumbiehl.
    - Make it explicit that we don't cannibalize one-hop circuits. This
      happens in the wild, but doesn't turn out to be a problem because
      we fortunately don't use those circuits. Many thanks to outofwords
      for the initial analysis and to swissknife who confirmed that
      two-hop circuits are actually created.
    - Make directory mirrors report non-zero dirreq-v[23]-shares again.
      Fixes bug 1564; bugfix on 0.2.2.9-alpha.
    - Eliminate a case where a circuit build time warning was displayed
      after network connectivity resumed. Bugfix on 0.2.2.2-alpha.


Changes in version 0.2.1.26 - 2010-05-02
  Tor 0.2.1.26 addresses the recent connection and memory overload
  problems we've been seeing on relays, especially relays with their
  DirPort open. If your relay has been crashing, or you turned it off
  because it used too many resources, give this release a try.

  This release also fixes yet another instance of broken OpenSSL libraries
  that was causing some relays to drop out of the consensus.

  o Major bugfixes:
    - Teach relays to defend themselves from connection overload. Relays
      now close idle circuits early if it looks like they were intended
      for directory fetches. Relays are also more aggressive about closing
      TLS connections that have no circuits on them. Such circuits are
      unlikely to be re-used, and tens of thousands of them were piling
      up at the fast relays, causing the relays to run out of sockets
      and memory. Bugfix on 0.2.0.22-rc (where clients started tunneling
      their directory fetches over TLS).
    - Fix SSL renegotiation behavior on OpenSSL versions like on Centos
      that claim to be earlier than 0.9.8m, but which have in reality
      backported huge swaths of 0.9.8m or 0.9.8n renegotiation
      behavior. Possible fix for some cases of bug 1346.
    - Directory mirrors were fetching relay descriptors only from v2
      directory authorities, rather than v3 authorities like they should.
      Only 2 v2 authorities remain (compared to 7 v3 authorities), leading
      to a serious bottleneck. Bugfix on 0.2.0.9-alpha. Fixes bug 1324.

  o Minor bugfixes:
    - Finally get rid of the deprecated and now harmful notion of "clique
      mode", where directory authorities maintain TLS connections to
      every other relay.

  o Testsuite fixes:
    - In the util/threads test, no longer free the test_mutex before all
      worker threads have finished. Bugfix on 0.2.1.6-alpha.
    - The master thread could starve the worker threads quite badly on
      certain systems, causing them to run only partially in the allowed
      window. This resulted in test failures. Now the master thread sleeps
      occasionally for a few microseconds while the two worker-threads
      compete for the mutex. Bugfix on 0.2.0.1-alpha.


Changes in version 0.2.2.13-alpha - 2010-04-24
  Tor 0.2.2.13-alpha addresses the recent connection and memory overload
  problems we've been seeing on relays, especially relays with their
  DirPort open. If your relay has been crashing, or you turned it off
  because it used too many resources, give this release a try.

  o Major bugfixes:
    - Teach relays to defend themselves from connection overload. Relays
      now close idle circuits early if it looks like they were intended
      for directory fetches. Relays are also more aggressive about closing
      TLS connections that have no circuits on them. Such circuits are
      unlikely to be re-used, and tens of thousands of them were piling
      up at the fast relays, causing the relays to run out of sockets
      and memory. Bugfix on 0.2.0.22-rc (where clients started tunneling
      their directory fetches over TLS).

  o Minor features:
    - Finally get rid of the deprecated and now harmful notion of "clique
      mode", where directory authorities maintain TLS connections to
      every other relay.
    - Directory authorities now do an immediate reachability check as soon
      as they hear about a new relay. This change should slightly reduce
      the time between setting up a relay and getting listed as running
      in the consensus. It should also improve the time between setting
      up a bridge and seeing use by bridge users.
    - Directory authorities no longer launch a TLS connection to every
      relay as they startup. Now that we have 2k+ descriptors cached,
      the resulting network hiccup is becoming a burden. Besides,
      authorities already avoid voting about Running for the first half
      hour of their uptime.


Changes in version 0.2.2.12-alpha - 2010-04-20
  Tor 0.2.2.12-alpha fixes a critical bug in how directory authorities
  handle and vote on descriptors. It was causing relays to drop out of
  the consensus.

  o Major bugfixes:
    - Many relays have been falling out of the consensus lately because
      not enough authorities know about their descriptor for them to get
      a majority of votes. When we deprecated the v2 directory protocol,
      we got rid of the only way that v3 authorities can hear from each
      other about other descriptors. Now authorities examine every v3
      vote for new descriptors, and fetch them from that authority. Bugfix
      on 0.2.1.23.
    - Fix two typos in tor_vasprintf() that broke the compile on Windows,
      and a warning in or.h related to bandwidth_weight_rule_t that
      prevented clean compile on OS X. Fixes bug 1363; bugfix on
      0.2.2.11-alpha.
    - Fix a segfault on relays when DirReqStatistics is enabled
      and 24 hours pass. Bug found by keb. Fixes bug 1365; bugfix on
      0.2.2.11-alpha.

  o Minor bugfixes:
    - Demote a confusing TLS warning that relay operators might get when
      someone tries to talk to their OrPort. It is neither the operator's
      fault nor can they do anything about it. Fixes bug 1364; bugfix
      on 0.2.0.14-alpha.


Changes in version 0.2.2.11-alpha - 2010-04-15
  Tor 0.2.2.11-alpha fixes yet another instance of broken OpenSSL
  libraries that was causing some relays to drop out of the consensus.

  o Major bugfixes:
    - Directory mirrors were fetching relay descriptors only from v2
      directory authorities, rather than v3 authorities like they should.
      Only 2 v2 authorities remain (compared to 7 v3 authorities), leading
      to a serious bottleneck. Bugfix on 0.2.0.9-alpha. Fixes bug 1324.
    - Fix a parsing error that made every possible value of
      CircPriorityHalflifeMsec get treated as "1 msec". Bugfix
      on 0.2.2.7-alpha. Rename CircPriorityHalflifeMsec to
      CircuitPriorityHalflifeMsec, so authorities can tell newer relays
      about the option without breaking older ones.
    - Fix SSL renegotiation behavior on OpenSSL versions like on Centos
      that claim to be earlier than 0.9.8m, but which have in reality
      backported huge swaths of 0.9.8m or 0.9.8n renegotiation
      behavior. Possible fix for some cases of bug 1346.

  o Minor features:
    - Experiment with a more aggressive approach to preventing clients
      from making one-hop exit streams. Exit relays who want to try it
      out can set "RefuseUnknownExits 1" in their torrc, and then look
      for "Attempt by %s to open a stream" log messages. Let us know
      how it goes!
    - Add support for statically linking zlib by specifying
      --enable-static-zlib, to go with our support for statically linking
      openssl and libevent. Resolves bug 1358.

  o Minor bugfixes:
    - Fix a segfault that happens whenever a Tor client that is using
      libevent2's bufferevents gets a hup signal. Bugfix on 0.2.2.5-alpha;
      fixes bug 1341.
    - When we cleaned up the contrib/tor-exit-notice.html file, we left
      out the first line. Fixes bug 1295.
    - When building the manpage from a tarball, we required asciidoc, but
      the asciidoc -> roff/html conversion was already done for the
      tarball. Make 'make' complain only when we need asciidoc (either
      because we're compiling directly from git, or because we altered
      the asciidoc manpage in the tarball). Bugfix on 0.2.2.9-alpha.
    - When none of the directory authorities vote on any params, Tor
      segfaulted when trying to make the consensus from the votes. We
      didn't trigger the bug in practice, because authorities do include
      params in their votes. Bugfix on 0.2.2.10-alpha; fixes bug 1322.

  o Testsuite fixes:
    - In the util/threads test, no longer free the test_mutex before all
      worker threads have finished. Bugfix on 0.2.1.6-alpha.
    - The master thread could starve the worker threads quite badly on
      certain systems, causing them to run only partially in the allowed
      window. This resulted in test failures. Now the master thread sleeps
      occasionally for a few microseconds while the two worker-threads
      compete for the mutex. Bugfix on 0.2.0.1-alpha.


Changes in version 0.2.2.10-alpha - 2010-03-07
  Tor 0.2.2.10-alpha fixes a regression introduced in 0.2.2.9-alpha that
  could prevent relays from guessing their IP address correctly. It also
  starts the groundwork for another client-side performance boost, since
  currently we're not making efficient use of relays that have both the
  Guard flag and the Exit flag.

  o Major bugfixes:
    - Fix a regression from our patch for bug 1244 that caused relays
      to guess their IP address incorrectly if they didn't set Address
      in their torrc and/or their address fails to resolve. Bugfix on
      0.2.2.9-alpha; fixes bug 1269.

  o Major features (performance):
    - Directory authorities now compute consensus weightings that instruct
      clients how to weight relays flagged as Guard, Exit, Guard+Exit,
      and no flag. Clients that use these weightings will distribute
      network load more evenly across these different relay types. The
      weightings are in the consensus so we can change them globally in
      the future. Extra thanks to "outofwords" for finding some nasty
      security bugs in the first implementation of this feature.

  o Minor features (performance):
    - Always perform router selections using weighted relay bandwidth,
      even if we don't need a high capacity circuit at the time. Non-fast
      circuits now only differ from fast ones in that they can use relays
      not marked with the Fast flag. This "feature" could turn out to
      be a horrible bug; we should investigate more before it goes into
      a stable release.

  o Minor features:
    - Allow disabling building of the manpages. Skipping the manpage
      speeds up the build considerably.

  o Minor bugfixes (on 0.2.2.x):
    - Fix a memleak in the EXTENDCIRCUIT logic. Spotted by coverity.
      Bugfix on 0.2.2.9-alpha.
    - Disallow values larger than INT32_MAX for PerConnBWRate|Burst
      config option. Bugfix on 0.2.2.7-alpha.
    - Ship the asciidoc-helper file in the tarball, so that people can
      build from source if they want to, and touching the .1.txt files
      doesn't break the build. Bugfix on 0.2.2.9-alpha.

  o Minor bugfixes (on 0.2.1.x or earlier):
    - Fix a dereference-then-NULL-check sequence when publishing
      descriptors. Bugfix on 0.2.1.5-alpha. Discovered by ekir; fixes
      bug 1255.
    - Fix another dereference-then-NULL-check sequence. Bugfix on
      0.2.1.14-rc. Discovered by ekir; fixes bug 1256.
    - Make sure we treat potentially not NUL-terminated strings correctly.
      Bugfix on 0.1.1.13-alpha. Discovered by rieo; fixes bug 1257.

  o Code simplifications and refactoring:
    - Fix some urls in the exit notice file and make it XHTML1.1 strict
      compliant. Based on a patch from Christian Kujau.
    - Don't use sed in asciidoc-helper anymore.
    - Make the build process fail if asciidoc cannot be found and
      building with asciidoc isn't disabled.


Changes in version 0.2.2.9-alpha - 2010-02-22
  Tor 0.2.2.9-alpha makes Tor work again on the latest OS X, updates the
  location of a directory authority, and cleans up a bunch of small bugs.

  o Directory authority changes:
    - Change IP address for dannenberg (v3 directory authority), and
      remove moria2 (obsolete v1, v2 directory authority and v0 hidden
      service directory authority) from the list.

  o Major bugfixes:
    - Make Tor work again on the latest OS X: when deciding whether to
      use strange flags to turn TLS renegotiation on, detect the OpenSSL
      version at run-time, not compile time. We need to do this because
      Apple doesn't update its dev-tools headers when it updates its
      libraries in a security patch.
    - Fix a potential buffer overflow in lookup_last_hid_serv_request()
      that could happen on 32-bit platforms with 64-bit time_t. Also fix
      a memory leak when requesting a hidden service descriptor we've
      requested before. Fixes bug 1242, bugfix on 0.2.0.18-alpha. Found
      by aakova.
    - Authorities could be tricked into giving out the Exit flag to relays
      that didn't allow exiting to any ports. This bug could screw
      with load balancing and stats. Bugfix on 0.1.1.6-alpha; fixes bug
      1238. Bug discovered by Martin Kowalczyk.
    - When freeing a session key, zero it out completely. We only zeroed
      the first ptrsize bytes. Bugfix on 0.0.2pre8. Discovered and
      patched by ekir. Fixes bug 1254.

  o Minor bugfixes:
    - Fix static compilation by listing the openssl libraries in the right
      order. Bugfix on Tor 0.2.2.8-alpha; fixes bug 1237.
    - Resume handling .exit hostnames in a special way: originally we
      stripped the .exit part and used the requested exit relay. In
      0.2.2.1-alpha we stopped treating them in any special way, meaning
      if you use a .exit address then Tor will pass it on to the exit
      relay. Now we reject the .exit stream outright, since that behavior
      might be more expected by the user. Found and diagnosed by Scott
      Bennett and Downie on or-talk.
    - Don't spam the controller with events when we have no file
      descriptors available. Bugfix on 0.2.1.5-alpha. (Rate-limiting
      for log messages was already solved from bug 748.)
    - Avoid a bogus overlapped memcpy in tor_addr_copy(). Reported by
      "memcpyfail".
    - Make the DNSPort option work with libevent 2.x. Don't alter the
      behavior for libevent 1.x. Fixes bug 1143. Found by SwissTorExit.
    - Emit a GUARD DROPPED controller event for a case we missed.
    - Make more fields in the controller protocol case-insensitive, since
      control-spec.txt said they were.
    - Refactor resolve_my_address() to not use gethostbyname() anymore.
      Fixes bug 1244; bugfix on 0.0.2pre25. Reported by Mike Mestnik.
    - Fix a spec conformance issue: the network-status-version token
      must be the first token in a v3 consensus or vote. Discovered by
      parakeep. Bugfix on 0.2.0.3-alpha.

  o Code simplifications and refactoring:
    - Generate our manpage and HTML documentation using Asciidoc. This
      change should make it easier to maintain the documentation, and
      produce nicer HTML.
    - Remove the --enable-iphone option. According to reports from Marco
      Bonetti, Tor builds fine without any special tweaking on recent
      iPhone SDK versions.
    - Removed some unnecessary files from the source distribution. The
      AUTHORS file has now been merged into the people page on the
      website. The roadmaps and design doc can now be found in the
      projects directory in svn.
    - Enabled various circuit build timeout constants to be controlled
      by consensus parameters. Also set better defaults for these
      parameters based on experimentation on broadband and simulated
      high latency links.

  o Minor features:
    - The 'EXTENDCIRCUIT' control port command can now be used with
      a circ id of 0 and no path. This feature will cause Tor to build
      a new 'fast' general purpose circuit using its own path selection
      algorithms.
    - Added a BUILDTIMEOUT_SET controller event to describe changes
      to the circuit build timeout.
    - Future-proof the controller protocol a bit by ignoring keyword
      arguments we do not recognize.
    - Expand homedirs passed to tor-checkkey. This should silence a
      coverity complaint about passing a user-supplied string into
      open() without checking it.


Changes in version 0.2.1.25 - 2010-03-16
  Tor 0.2.1.25 fixes a regression introduced in 0.2.1.23 that could
  prevent relays from guessing their IP address correctly. It also fixes
  several minor potential security bugs.

  o Major bugfixes:
    - Fix a regression from our patch for bug 1244 that caused relays
      to guess their IP address incorrectly if they didn't set Address
      in their torrc and/or their address fails to resolve. Bugfix on
      0.2.1.23; fixes bug 1269.
    - When freeing a session key, zero it out completely. We only zeroed
      the first ptrsize bytes. Bugfix on 0.0.2pre8. Discovered and
      patched by ekir. Fixes bug 1254.

  o Minor bugfixes:
    - Fix a dereference-then-NULL-check sequence when publishing
      descriptors. Bugfix on 0.2.1.5-alpha. Discovered by ekir; fixes
      bug 1255.
    - Fix another dereference-then-NULL-check sequence. Bugfix on
      0.2.1.14-rc. Discovered by ekir; fixes bug 1256.
    - Make sure we treat potentially not NUL-terminated strings correctly.
      Bugfix on 0.1.1.13-alpha. Discovered by rieo; fixes bug 1257.



Changes in version 0.2.1.24 - 2010-02-21
  Tor 0.2.1.24 makes Tor work again on the latest OS X -- this time
  for sure!

  o Minor bugfixes:
    - Work correctly out-of-the-box with even more vendor-patched versions
      of OpenSSL. In particular, make it so Debian and OS X don't need
      customized patches to run/build.


Changes in version 0.2.1.23 - 2010-02-13
  Tor 0.2.1.23 fixes a huge client-side performance bug, makes Tor work
  again on the latest OS X, and updates the location of a directory
  authority.

  o Major bugfixes (performance):
    - We were selecting our guards uniformly at random, and then weighting
      which of our guards we'd use uniformly at random. This imbalance
      meant that Tor clients were severely limited on throughput (and
      probably latency too) by the first hop in their circuit. Now we
      select guards weighted by currently advertised bandwidth. We also
      automatically discard guards picked using the old algorithm. Fixes
      bug 1217; bugfix on 0.2.1.3-alpha. Found by Mike Perry.

  o Major bugfixes:
    - Make Tor work again on the latest OS X: when deciding whether to
      use strange flags to turn TLS renegotiation on, detect the OpenSSL
      version at run-time, not compile time. We need to do this because
      Apple doesn't update its dev-tools headers when it updates its
      libraries in a security patch.
    - Fix a potential buffer overflow in lookup_last_hid_serv_request()
      that could happen on 32-bit platforms with 64-bit time_t. Also fix
      a memory leak when requesting a hidden service descriptor we've
      requested before. Fixes bug 1242, bugfix on 0.2.0.18-alpha. Found
      by aakova.

  o Directory authority changes:
    - Change IP address for dannenberg (v3 directory authority), and
      remove moria2 (obsolete v1, v2 directory authority and v0 hidden
      service directory authority) from the list.

  o Minor bugfixes:
    - Refactor resolve_my_address() to not use gethostbyname() anymore.
      Fixes bug 1244; bugfix on 0.0.2pre25. Reported by Mike Mestnik.

  o Minor features:
    - Avoid a mad rush at the beginning of each month when each client
      rotates half of its guards. Instead we spread the rotation out
      throughout the month, but we still avoid leaving a precise timestamp
      in the state file about when we first picked the guard. Improves
      over the behavior introduced in 0.1.2.17.


Changes in version 0.2.2.8-alpha - 2010-01-26
  Tor 0.2.2.8-alpha fixes a crash bug in 0.2.2.7-alpha that has been
  causing bridge relays to disappear. If you're running a bridge,
  please upgrade.

  o Major bugfixes:
    - Fix a memory corruption bug on bridges that occured during the
      inclusion of stats data in extra-info descriptors. Also fix the
      interface for geoip_get_bridge_stats* to prevent similar bugs in
      the future. Diagnosis by Tas, patch by Karsten and Sebastian.
      Fixes bug 1208; bugfix on 0.2.2.7-alpha.

  o Minor bugfixes:
    - Ignore OutboundBindAddress when connecting to localhost.
      Connections to localhost need to come _from_ localhost, or else
      local servers (like DNS and outgoing HTTP/SOCKS proxies) will often
      refuse to listen.


Changes in version 0.2.2.7-alpha - 2010-01-19
  Tor 0.2.2.7-alpha fixes a huge client-side performance bug, as well
  as laying the groundwork for further relay-side performance fixes. It
  also starts cleaning up client behavior with respect to the EntryNodes,
  ExitNodes, and StrictNodes config options.

  This release also rotates two directory authority keys, due to a
  security breach of some of the Torproject servers.

  o Directory authority changes:
    - Rotate keys (both v3 identity and relay identity) for moria1
      and gabelmoo.

  o Major features (performance):
    - We were selecting our guards uniformly at random, and then weighting
      which of our guards we'd use uniformly at random. This imbalance
      meant that Tor clients were severely limited on throughput (and
      probably latency too) by the first hop in their circuit. Now we
      select guards weighted by currently advertised bandwidth. We also
      automatically discard guards picked using the old algorithm. Fixes
      bug 1217; bugfix on 0.2.1.3-alpha. Found by Mike Perry.
    - When choosing which cells to relay first, relays can now favor
      circuits that have been quiet recently, to provide lower latency
      for low-volume circuits. By default, relays enable or disable this
      feature based on a setting in the consensus. You can override
      this default by using the new "CircuitPriorityHalflife" config
      option. Design and code by Ian Goldberg, Can Tang, and Chris
      Alexander.
    - Add separate per-conn write limiting to go with the per-conn read
      limiting. We added a global write limit in Tor 0.1.2.5-alpha,
      but never per-conn write limits.
    - New consensus params "bwconnrate" and "bwconnburst" to let us
      rate-limit client connections as they enter the network. It's
      controlled in the consensus so we can turn it on and off for
      experiments. It's starting out off. Based on proposal 163.

  o Major features (relay selection options):
    - Switch to a StrictNodes config option, rather than the previous
      "StrictEntryNodes" / "StrictExitNodes" separation that was missing a
      "StrictExcludeNodes" option.
    - If EntryNodes, ExitNodes, ExcludeNodes, or ExcludeExitNodes
      change during a config reload, mark and discard all our origin
      circuits. This fix should address edge cases where we change the
      config options and but then choose a circuit that we created before
      the change.
    - If EntryNodes or ExitNodes are set, be more willing to use an
      unsuitable (e.g. slow or unstable) circuit. The user asked for it,
      they get it.
    - Make EntryNodes config option much more aggressive even when
      StrictNodes is not set. Before it would prepend your requested
      entrynodes to your list of guard nodes, but feel free to use others
      after that. Now it chooses only from your EntryNodes if any of
      those are available, and only falls back to others if a) they're
      all down and b) StrictNodes is not set.
    - Now we refresh your entry guards from EntryNodes at each consensus
      fetch -- rather than just at startup and then they slowly rot as
      the network changes.

  o Major bugfixes:
    - Stop bridge directory authorities from answering dbg-stability.txt
      directory queries, which would let people fetch a list of all
      bridge identities they track. Bugfix on 0.2.1.6-alpha.

  o Minor features:
    - Log a notice when we get a new control connection. Now it's easier
      for security-conscious users to recognize when a local application
      is knocking on their controller door. Suggested by bug 1196.
    - New config option "CircuitStreamTimeout" to override our internal
      timeout schedule for how many seconds until we detach a stream from
      a circuit and try a new circuit. If your network is particularly
      slow, you might want to set this to a number like 60.
    - New controller command "getinfo config-text". It returns the
      contents that Tor would write if you send it a SAVECONF command,
      so the controller can write the file to disk itself.
    - New options for SafeLogging to allow scrubbing only log messages
      generated while acting as a relay.
    - Ship the bridges spec file in the tarball too.
    - Avoid a mad rush at the beginning of each month when each client
      rotates half of its guards. Instead we spread the rotation out
      throughout the month, but we still avoid leaving a precise timestamp
      in the state file about when we first picked the guard. Improves
      over the behavior introduced in 0.1.2.17.

  o Minor bugfixes (compiling):
    - Fix compilation on OS X 10.3, which has a stub mlockall() but
      hides it. Bugfix on 0.2.2.6-alpha.
    - Fix compilation on Solaris by removing support for the
      DisableAllSwap config option. Solaris doesn't have an rlimit for
      mlockall, so we cannot use it safely. Fixes bug 1198; bugfix on
      0.2.2.6-alpha.

  o Minor bugfixes (crashes):
    - Do not segfault when writing buffer stats when we haven't observed
      a single circuit to report about. Found by Fabian Lanze. Bugfix on
      0.2.2.1-alpha.
    - If we're in the pathological case where there's no exit bandwidth
      but there is non-exit bandwidth, or no guard bandwidth but there
      is non-guard bandwidth, don't crash during path selection. Bugfix
      on 0.2.0.3-alpha.
    - Fix an impossible-to-actually-trigger buffer overflow in relay
      descriptor generation. Bugfix on 0.1.0.15.

  o Minor bugfixes (privacy):
    - Fix an instance where a Tor directory mirror might accidentally
      log the IP address of a misbehaving Tor client. Bugfix on
      0.1.0.1-rc.
    - Don't list Windows capabilities in relay descriptors. We never made
      use of them, and maybe it's a bad idea to publish them. Bugfix
      on 0.1.1.8-alpha.

  o Minor bugfixes (other):
    - Resolve an edge case in path weighting that could make us misweight
      our relay selection. Fixes bug 1203; bugfix on 0.0.8rc1.
    - Fix statistics on client numbers by country as seen by bridges that
      were broken in 0.2.2.1-alpha. Also switch to reporting full 24-hour
      intervals instead of variable 12-to-48-hour intervals.
    - After we free an internal connection structure, overwrite it
      with a different memory value than we use for overwriting a freed
      internal circuit structure. Should help with debugging. Suggested
      by bug 1055.
    - Update our OpenSSL 0.9.8l fix so that it works with OpenSSL 0.9.8m
      too.

  o Removed features:
    - Remove the HSAuthorityRecordStats option that version 0 hidden
      service authorities could have used to track statistics of overall
      hidden service usage.


Changes in version 0.2.1.22 - 2010-01-19
  Tor 0.2.1.22 fixes a critical privacy problem in bridge directory
  authorities -- it would tell you its whole history of bridge descriptors
  if you make the right directory request. This stable update also
  rotates two of the seven v3 directory authority keys and locations.

  o Directory authority changes:
    - Rotate keys (both v3 identity and relay identity) for moria1
      and gabelmoo.

  o Major bugfixes:
    - Stop bridge directory authorities from answering dbg-stability.txt
      directory queries, which would let people fetch a list of all
      bridge identities they track. Bugfix on 0.2.1.6-alpha.


Changes in version 0.2.1.21 - 2009-12-21
  Tor 0.2.1.21 fixes an incompatibility with the most recent OpenSSL
  library. If you use Tor on Linux / Unix and you're getting SSL
  renegotiation errors, upgrading should help. We also recommend an
  upgrade if you're an exit relay.

  o Major bugfixes:
    - Work around a security feature in OpenSSL 0.9.8l that prevents our
      handshake from working unless we explicitly tell OpenSSL that we
      are using SSL renegotiation safely. We are, of course, but OpenSSL
      0.9.8l won't work unless we say we are.
    - Avoid crashing if the client is trying to upload many bytes and the
      circuit gets torn down at the same time, or if the flip side
      happens on the exit relay. Bugfix on 0.2.0.1-alpha; fixes bug 1150.

  o Minor bugfixes:
    - Do not refuse to learn about authority certs and v2 networkstatus
      documents that are older than the latest consensus. This bug might
      have degraded client bootstrapping. Bugfix on 0.2.0.10-alpha.
      Spotted and fixed by xmux.
    - Fix a couple of very-hard-to-trigger memory leaks, and one hard-to-
      trigger platform-specific option misparsing case found by Coverity
      Scan.
    - Fix a compilation warning on Fedora 12 by removing an impossible-to-
      trigger assert. Fixes bug 1173.


Changes in version 0.2.2.6-alpha - 2009-11-19
  Tor 0.2.2.6-alpha lays the groundwork for many upcoming features:
  support for the new lower-footprint "microdescriptor" directory design,
  future-proofing our consensus format against new hash functions or
  other changes, and an Android port. It also makes Tor compatible with
  the upcoming OpenSSL 0.9.8l release, and fixes a variety of bugs.

  o Major features:
    - Directory authorities can now create, vote on, and serve multiple
      parallel formats of directory data as part of their voting process.
      Partially implements Proposal 162: "Publish the consensus in
      multiple flavors".
    - Directory authorities can now agree on and publish small summaries
      of router information that clients can use in place of regular
      server descriptors. This transition will eventually allow clients
      to use far less bandwidth for downloading information about the
      network. Begins the implementation of Proposal 158: "Clients
      download consensus + microdescriptors".
    - The directory voting system is now extensible to use multiple hash
      algorithms for signatures and resource selection. Newer formats
      are signed with SHA256, with a possibility for moving to a better
      hash algorithm in the future.
    - New DisableAllSwap option. If set to 1, Tor will attempt to lock all
      current and future memory pages via mlockall(). On supported
      platforms (modern Linux and probably BSD but not Windows or OS X),
      this should effectively disable any and all attempts to page out
      memory. This option requires that you start your Tor as root --
      if you use DisableAllSwap, please consider using the User option
      to properly reduce the privileges of your Tor.
    - Numerous changes, bugfixes, and workarounds from Nathan Freitas
      to help Tor build correctly for Android phones.

  o Major bugfixes:
    - Work around a security feature in OpenSSL 0.9.8l that prevents our
      handshake from working unless we explicitly tell OpenSSL that we
      are using SSL renegotiation safely. We are, but OpenSSL 0.9.8l
      won't work unless we say we are.

  o Minor bugfixes:
    - Fix a crash bug when trying to initialize the evdns module in
      Libevent 2. Bugfix on 0.2.1.16-rc.
    - Stop logging at severity 'warn' when some other Tor client tries
      to establish a circuit with us using weak DH keys. It's a protocol
      violation, but that doesn't mean ordinary users need to hear about
      it. Fixes the bug part of bug 1114. Bugfix on 0.1.0.13.
    - Do not refuse to learn about authority certs and v2 networkstatus
      documents that are older than the latest consensus. This bug might
      have degraded client bootstrapping. Bugfix on 0.2.0.10-alpha.
      Spotted and fixed by xmux.
    - Fix numerous small code-flaws found by Coverity Scan Rung 3.
    - If all authorities restart at once right before a consensus vote,
      nobody will vote about "Running", and clients will get a consensus
      with no usable relays. Instead, authorities refuse to build a
      consensus if this happens. Bugfix on 0.2.0.10-alpha; fixes bug 1066.
    - If your relay can't keep up with the number of incoming create
      cells, it would log one warning per failure into your logs. Limit
      warnings to 1 per minute. Bugfix on 0.0.2pre10; fixes bug 1042.
    - Bridges now use "reject *:*" as their default exit policy. Bugfix
      on 0.2.0.3-alpha; fixes bug 1113.
    - Fix a memory leak on directory authorities during voting that was
      introduced in 0.2.2.1-alpha. Found via valgrind.


Changes in version 0.2.1.20 - 2009-10-15
  Tor 0.2.1.20 fixes a crash bug when you're accessing many hidden
  services at once, prepares for more performance improvements, and
  fixes a bunch of smaller bugs.

  The Windows and OS X bundles also include a more recent Vidalia,
  and switch from Privoxy to Polipo.

  The OS X installers are now drag and drop. It's best to un-install
  Tor/Vidalia and then install this new bundle, rather than upgrade. If
  you want to upgrade, you'll need to update the paths for Tor and Polipo
  in the Vidalia Settings window.

  o Major bugfixes:
    - Send circuit or stream sendme cells when our window has decreased
      by 100 cells, not when it has decreased by 101 cells. Bug uncovered
      by Karsten when testing the "reduce circuit window" performance
      patch. Bugfix on the 54th commit on Tor -- from July 2002,
      before the release of Tor 0.0.0. This is the new winner of the
      oldest-bug prize.
    - Fix a remotely triggerable memory leak when a consensus document
      contains more than one signature from the same voter. Bugfix on
      0.2.0.3-alpha.
    - Avoid segfault in rare cases when finishing an introduction circuit
      as a client and finding out that we don't have an introduction key
      for it. Fixes bug 1073. Reported by Aaron Swartz.

  o Major features:
    - Tor now reads the "circwindow" parameter out of the consensus,
      and uses that value for its circuit package window rather than the
      default of 1000 cells. Begins the implementation of proposal 168.

  o New directory authorities:
    - Set up urras (run by Jacob Appelbaum) as the seventh v3 directory
      authority.
    - Move moria1 and tonga to alternate IP addresses.

  o Minor bugfixes:
    - Fix a signed/unsigned compile warning in 0.2.1.19.
    - Fix possible segmentation fault on directory authorities. Bugfix on
      0.2.1.14-rc.
    - Fix an extremely rare infinite recursion bug that could occur if
      we tried to log a message after shutting down the log subsystem.
      Found by Matt Edman. Bugfix on 0.2.0.16-alpha.
    - Fix an obscure bug where hidden services on 64-bit big-endian
      systems might mis-read the timestamp in v3 introduce cells, and
      refuse to connect back to the client. Discovered by "rotor".
      Bugfix on 0.2.1.6-alpha.
    - We were triggering a CLOCK_SKEW controller status event whenever
      we connect via the v2 connection protocol to any relay that has
      a wrong clock. Instead, we should only inform the controller when
      it's a trusted authority that claims our clock is wrong. Bugfix
      on 0.2.0.20-rc; starts to fix bug 1074. Reported by SwissTorExit.
    - We were telling the controller about CHECKING_REACHABILITY and
      REACHABILITY_FAILED status events whenever we launch a testing
      circuit or notice that one has failed. Instead, only tell the
      controller when we want to inform the user of overall success or
      overall failure. Bugfix on 0.1.2.6-alpha. Fixes bug 1075. Reported
      by SwissTorExit.
    - Don't warn when we're using a circuit that ends with a node
      excluded in ExcludeExitNodes, but the circuit is not used to access
      the outside world. This should help fix bug 1090. Bugfix on
      0.2.1.6-alpha.
    - Work around a small memory leak in some versions of OpenSSL that
      stopped the memory used by the hostname TLS extension from being
      freed.

  o Minor features:
    - Add a "getinfo status/accepted-server-descriptor" controller
      command, which is the recommended way for controllers to learn
      whether our server descriptor has been successfully received by at
      least on directory authority. Un-recommend good-server-descriptor
      getinfo and status events until we have a better design for them.


Changes in version 0.2.2.5-alpha - 2009-10-11
  Tor 0.2.2.5-alpha fixes a few compile problems in 0.2.2.4-alpha.

  o Major bugfixes:
    - Make the tarball compile again. Oops. Bugfix on 0.2.2.4-alpha.

  o Directory authorities:
    - Temporarily (just for this release) move dizum to an alternate
      IP address.


Changes in version 0.2.2.4-alpha - 2009-10-10
  Tor 0.2.2.4-alpha fixes more crash bugs in 0.2.2.2-alpha. It also
  introduces a new unit test framework, shifts directry authority
  addresses around to reduce the impact from recent blocking events,
  and fixes a few smaller bugs.

  o Major bugfixes:
    - Fix several more asserts in the circuit_build_times code, for
      example one that causes Tor to fail to start once we have
      accumulated 5000 build times in the state file. Bugfixes on
      0.2.2.2-alpha; fixes bug 1108.

  o New directory authorities:
    - Move moria1 and Tonga to alternate IP addresses.

  o Minor features:
    - Log SSL state transitions at debug level during handshake, and
      include SSL states in error messages. This may help debug future
      SSL handshake issues.
    - Add a new "Handshake" log domain for activities that happen
      during the TLS handshake.
    - Revert to the "June 3 2009" ip-to-country file. The September one
      seems to have removed most US IP addresses.
    - Directory authorities now reject Tor relays with versions less than
      0.1.2.14. This step cuts out four relays from the current network,
      none of which are very big.

  o Minor bugfixes:
    - Fix a couple of smaller issues with gathering statistics. Bugfixes
      on 0.2.2.1-alpha.
    - Fix two memory leaks in the error case of
      circuit_build_times_parse_state(). Bugfix on 0.2.2.2-alpha.
    - Don't count one-hop circuits when we're estimating how long it
      takes circuits to build on average. Otherwise we'll set our circuit
      build timeout lower than we should. Bugfix on 0.2.2.2-alpha.
    - Directory authorities no longer change their opinion of, or vote on,
      whether a router is Running, unless they have themselves been
      online long enough to have some idea. Bugfix on 0.2.0.6-alpha.
      Fixes bug 1023.

  o Code simplifications and refactoring:
    - Revise our unit tests to use the "tinytest" framework, so we
      can run tests in their own processes, have smarter setup/teardown
      code, and so on. The unit test code has moved to its own
      subdirectory, and has been split into multiple modules.


Changes in version 0.2.2.3-alpha - 2009-09-23
  Tor 0.2.2.3-alpha fixes a few crash bugs in 0.2.2.2-alpha.

  o Major bugfixes:
    - Fix an overzealous assert in our new circuit build timeout code.
      Bugfix on 0.2.2.2-alpha; fixes bug 1103.

  o Minor bugfixes:
    - If the networkstatus consensus tells us that we should use a
      negative circuit package window, ignore it. Otherwise we'll
      believe it and then trigger an assert. Bugfix on 0.2.2.2-alpha.


Changes in version 0.2.2.2-alpha - 2009-09-21
  Tor 0.2.2.2-alpha introduces our latest performance improvement for
  clients: Tor tracks the average time it takes to build a circuit, and
  avoids using circuits that take too long to build. For fast connections,
  this feature can cut your expected latency in half. For slow or flaky
  connections, it could ruin your Tor experience. Let us know if it does!

  o Major features:
    - Tor now tracks how long it takes to build client-side circuits
      over time, and adapts its timeout to local network performance.
      Since a circuit that takes a long time to build will also provide
      bad performance, we get significant latency improvements by
      discarding the slowest 20% of circuits. Specifically, Tor creates
      circuits more aggressively than usual until it has enough data
      points for a good timeout estimate. Implements proposal 151.
      We are especially looking for reports (good and bad) from users with
      both EDGE and broadband connections that can move from broadband
      to EDGE and find out if the build-time data in the .tor/state gets
      reset without loss of Tor usability. You should also see a notice
      log message telling you that Tor has reset its timeout.
    - Directory authorities can now vote on arbitary integer values as
      part of the consensus process. This is designed to help set
      network-wide parameters. Implements proposal 167.
    - Tor now reads the "circwindow" parameter out of the consensus,
      and uses that value for its circuit package window rather than the
      default of 1000 cells. Begins the implementation of proposal 168.

  o Major bugfixes:
    - Fix a remotely triggerable memory leak when a consensus document
      contains more than one signature from the same voter. Bugfix on
      0.2.0.3-alpha.

  o Minor bugfixes:
    - Fix an extremely rare infinite recursion bug that could occur if
      we tried to log a message after shutting down the log subsystem.
      Found by Matt Edman. Bugfix on 0.2.0.16-alpha.
    - Fix parsing for memory or time units given without a space between
      the number and the unit. Bugfix on 0.2.2.1-alpha; fixes bug 1076.
    - A networkstatus vote must contain exactly one signature. Spec
      conformance issue. Bugfix on 0.2.0.3-alpha.
    - Fix an obscure bug where hidden services on 64-bit big-endian
      systems might mis-read the timestamp in v3 introduce cells, and
      refuse to connect back to the client. Discovered by "rotor".
      Bugfix on 0.2.1.6-alpha.
    - We were triggering a CLOCK_SKEW controller status event whenever
      we connect via the v2 connection protocol to any relay that has
      a wrong clock. Instead, we should only inform the controller when
      it's a trusted authority that claims our clock is wrong. Bugfix
      on 0.2.0.20-rc; starts to fix bug 1074. Reported by SwissTorExit.
    - We were telling the controller about CHECKING_REACHABILITY and
      REACHABILITY_FAILED status events whenever we launch a testing
      circuit or notice that one has failed. Instead, only tell the
      controller when we want to inform the user of overall success or
      overall failure. Bugfix on 0.1.2.6-alpha. Fixes bug 1075. Reported
      by SwissTorExit.
    - Don't warn when we're using a circuit that ends with a node
      excluded in ExcludeExitNodes, but the circuit is not used to access
      the outside world. This should help fix bug 1090, but more problems
      remain. Bugfix on 0.2.1.6-alpha.
    - Work around a small memory leak in some versions of OpenSSL that
      stopped the memory used by the hostname TLS extension from being
      freed.
    - Make our 'torify' script more portable; if we have only one of
      'torsocks' or 'tsocks' installed, don't complain to the user;
      and explain our warning about tsocks better.

  o Minor features:
    - Add a "getinfo status/accepted-server-descriptor" controller
      command, which is the recommended way for controllers to learn
      whether our server descriptor has been successfully received by at
      least on directory authority. Un-recommend good-server-descriptor
      getinfo and status events until we have a better design for them.
    - Update to the "September 4 2009" ip-to-country file.


Changes in version 0.2.2.1-alpha - 2009-08-26
  Tor 0.2.2.1-alpha disables ".exit" address notation by default, allows
  Tor clients to bootstrap on networks where only port 80 is reachable,
  makes it more straightforward to support hardware crypto accelerators,
  and starts the groundwork for gathering stats safely at relays.

  o Security fixes:
    - Start the process of disabling ".exit" address notation, since it
      can be used for a variety of esoteric application-level attacks
      on users. To reenable it, set "AllowDotExit 1" in your torrc. Fix
      on 0.0.9rc5.

  o New directory authorities:
    - Set up urras (run by Jacob Appelbaum) as the seventh v3 directory
      authority.

  o Major features:
    - New AccelName and AccelDir options add support for dynamic OpenSSL
      hardware crypto acceleration engines.
    - Tor now supports tunneling all of its outgoing connections over
      a SOCKS proxy, using the SOCKS4Proxy and/or SOCKS5Proxy
      configuration options. Code by Christopher Davis.

  o Major bugfixes:
    - Send circuit or stream sendme cells when our window has decreased
      by 100 cells, not when it has decreased by 101 cells. Bug uncovered
      by Karsten when testing the "reduce circuit window" performance
      patch. Bugfix on the 54th commit on Tor -- from July 2002,
      before the release of Tor 0.0.0. This is the new winner of the
      oldest-bug prize.

  o New options for gathering stats safely:
    - Directory mirrors that set "DirReqStatistics 1" write statistics
      about directory requests to disk every 24 hours. As compared to the
      --enable-geoip-stats flag in 0.2.1.x, there are a few improvements:
      1) stats are written to disk exactly every 24 hours; 2) estimated
      shares of v2 and v3 requests are determined as mean values, not at
      the end of a measurement period; 3) unresolved requests are listed
      with country code '??'; 4) directories also measure download times.
    - Exit nodes that set "ExitPortStatistics 1" write statistics on the
      number of exit streams and transferred bytes per port to disk every
      24 hours.
    - Relays that set "CellStatistics 1" write statistics on how long
      cells spend in their circuit queues to disk every 24 hours.
    - Entry nodes that set "EntryStatistics 1" write statistics on the
      rough number and origins of connecting clients to disk every 24
      hours.
    - Relays that write any of the above statistics to disk and set
      "ExtraInfoStatistics 1" include the past 24 hours of statistics in
      their extra-info documents.

  o Minor features:
    - New --digests command-line switch to output the digests of the
      source files Tor was built with.
    - The "torify" script now uses torsocks where available.
    - The memarea code now uses a sentinel value at the end of each area
      to make sure nothing writes beyond the end of an area. This might
      help debug some conceivable causes of bug 930.
    - Time and memory units in the configuration file can now be set to
      fractional units. For example, "2.5 GB" is now a valid value for
      AccountingMax.
    - Certain Tor clients (such as those behind check.torproject.org) may
      want to fetch the consensus in an extra early manner. To enable this
      a user may now set FetchDirInfoExtraEarly to 1. This also depends on
      setting FetchDirInfoEarly to 1. Previous behavior will stay the same
      as only certain clients who must have this information sooner should
      set this option.
    - Instead of adding the svn revision to the Tor version string, report
      the git commit (when we're building from a git checkout).

  o Minor bugfixes:
    - If any of the v3 certs we download are unparseable, we should
      actually notice the failure so we don't retry indefinitely. Bugfix
      on 0.2.0.x; reported by "rotator".
    - If the cached cert file is unparseable, warn but don't exit.
    - Fix possible segmentation fault on directory authorities. Bugfix on
      0.2.1.14-rc.
    - When Tor fails to parse a descriptor of any kind, dump it to disk.
      Might help diagnosing bug 1051.

  o Deprecated and removed features:
    - The controller no longer accepts the old obsolete "addr-mappings/"
      or "unregistered-servers-" GETINFO values.
    - Hidden services no longer publish version 0 descriptors, and clients
      do not request or use version 0 descriptors. However, the old hidden
      service authorities still accept and serve version 0 descriptors
      when contacted by older hidden services/clients.
    - The EXTENDED_EVENTS and VERBOSE_NAMES controller features are now
      always on; using them is necessary for correct forward-compatible
      controllers.
    - Remove support for .noconnect style addresses. Nobody was using
      them, and they provided another avenue for detecting Tor users
      via application-level web tricks.

  o Packaging changes:
    - Upgrade Vidalia from 0.1.15 to 0.2.3 in the Windows and OS X
      installer bundles. See
      https://trac.vidalia-project.net/browser/vidalia/tags/vidalia-0.2.3/CHANGELOG
      for details of what's new in Vidalia 0.2.3.
    - Windows Vidalia Bundle: update Privoxy from 3.0.6 to 3.0.14-beta.
    - OS X Vidalia Bundle: move to Polipo 1.0.4 with Tor specific
      configuration file, rather than the old Privoxy.
    - OS X Vidalia Bundle: Vidalia, Tor, and Polipo are compiled as
      x86-only for better compatibility with OS X 10.6, aka Snow Leopard.
    - OS X Tor Expert Bundle: Tor is compiled as x86-only for
      better compatibility with OS X 10.6, aka Snow Leopard.
    - OS X Vidalia Bundle: The multi-package installer is now replaced
      by a simple drag and drop to the /Applications folder. This change
      occurred with the upgrade to Vidalia 0.2.3.


Changes in version 0.2.1.19 - 2009-07-28
  Tor 0.2.1.19 fixes a major bug with accessing and providing hidden
  services on Tor 0.2.1.3-alpha through 0.2.1.18.

  o Major bugfixes:
    - Make accessing hidden services on 0.2.1.x work right again.
      Bugfix on 0.2.1.3-alpha; workaround for bug 1038. Diagnosis and
      part of patch provided by "optimist".

  o Minor features:
    - When a relay/bridge is writing out its identity key fingerprint to
      the "fingerprint" file and to its logs, write it without spaces. Now
      it will look like the fingerprints in our bridges documentation,
      and confuse fewer users.

  o Minor bugfixes:
    - Relays no longer publish a new server descriptor if they change
      their MaxAdvertisedBandwidth config option but it doesn't end up
      changing their advertised bandwidth numbers. Bugfix on 0.2.0.28-rc;
      fixes bug 1026. Patch from Sebastian.
    - Avoid leaking memory every time we get a create cell but we have
      so many already queued that we refuse it. Bugfix on 0.2.0.19-alpha;
      fixes bug 1034. Reported by BarkerJr.


Changes in version 0.2.1.18 - 2009-07-24
  Tor 0.2.1.18 lays the foundations for performance improvements,
  adds status events to help users diagnose bootstrap problems, adds
  optional authentication/authorization for hidden services, fixes a
  variety of potential anonymity problems, and includes a huge pile of
  other features and bug fixes.

  o Build fixes:
    - Add LIBS=-lrt to Makefile.am so the Tor RPMs use a static libevent.


Changes in version 0.2.1.17-rc - 2009-07-07
  Tor 0.2.1.17-rc marks the fourth -- and hopefully last -- release
  candidate for the 0.2.1.x series. It lays the groundwork for further
  client performance improvements, and also fixes a big bug with directory
  authorities that were causing them to assign Guard and Stable flags
  poorly.

  The Windows bundles also finally include the geoip database that we
  thought we'd been shipping since 0.2.0.x (oops), and the OS X bundles
  should actually install Torbutton rather than giving you a cryptic
  failure message (oops).

  o Major features:
    - Clients now use the bandwidth values in the consensus, rather than
      the bandwidth values in each relay descriptor. This approach opens
      the door to more accurate bandwidth estimates once the directory
      authorities start doing active measurements. Implements more of
      proposal 141.

  o Major bugfixes:
    - When Tor clients restart after 1-5 days, they discard all their
      cached descriptors as too old, but they still use the cached
      consensus document. This approach is good for robustness, but
      bad for performance: since they don't know any bandwidths, they
      end up choosing at random rather than weighting their choice by
      speed. Fixed by the above feature of putting bandwidths in the
      consensus. Bugfix on 0.2.0.x.
    - Directory authorities were neglecting to mark relays down in their
      internal histories if the relays fall off the routerlist without
      ever being found unreachable. So there were relays in the histories
      that haven't been seen for eight months, and are listed as being
      up for eight months. This wreaked havoc on the "median wfu"
      and "median mtbf" calculations, in turn making Guard and Stable
      flags very wrong, hurting network performance. Fixes bugs 696 and
      969. Bugfix on 0.2.0.6-alpha.

  o Minor bugfixes:
    - Serve the DirPortFrontPage page even when we have been approaching
      our quotas recently. Fixes bug 1013; bugfix on 0.2.1.8-alpha.
    - The control port would close the connection before flushing long
      replies, such as the network consensus, if a QUIT command was issued
      before the reply had completed. Now, the control port flushes all
      pending replies before closing the connection. Also fixed a spurious
      warning when a QUIT command is issued after a malformed or rejected
      AUTHENTICATE command, but before the connection was closed. Patch
      by Marcus Griep. Bugfix on 0.2.0.x; fixes bugs 1015 and 1016.
    - When we can't find an intro key for a v2 hidden service descriptor,
      fall back to the v0 hidden service descriptor and log a bug message.
      Workaround for bug 1024.
    - Fix a log message that did not respect the SafeLogging option.
      Resolves bug 1027.

  o Minor features:
    - If we're a relay and we change our IP address, be more verbose
      about the reason that made us change. Should help track down
      further bugs for relays on dynamic IP addresses.


Changes in version 0.2.0.35 - 2009-06-24
  o Security fix:
    - Avoid crashing in the presence of certain malformed descriptors.
      Found by lark, and by automated fuzzing.
    - Fix an edge case where a malicious exit relay could convince a
      controller that the client's DNS question resolves to an internal IP
      address. Bug found and fixed by "optimist"; bugfix on 0.1.2.8-beta.

  o Major bugfixes:
    - Finally fix the bug where dynamic-IP relays disappear when their
      IP address changes: directory mirrors were mistakenly telling
      them their old address if they asked via begin_dir, so they
      never got an accurate answer about their new address, so they
      just vanished after a day. For belt-and-suspenders, relays that
      don't set Address in their config now avoid using begin_dir for
      all direct connections. Should fix bugs 827, 883, and 900.
    - Fix a timing-dependent, allocator-dependent, DNS-related crash bug
      that would occur on some exit nodes when DNS failures and timeouts
      occurred in certain patterns. Fix for bug 957.

  o Minor bugfixes:
    - When starting with a cache over a few days old, do not leak
      memory for the obsolete router descriptors in it. Bugfix on
      0.2.0.33; fixes bug 672.
    - Hidden service clients didn't use a cached service descriptor that
      was older than 15 minutes, but wouldn't fetch a new one either,
      because there was already one in the cache. Now, fetch a v2
      descriptor unless the same descriptor was added to the cache within
      the last 15 minutes. Fixes bug 997; reported by Marcus Griep.


Changes in version 0.2.1.16-rc - 2009-06-20
  Tor 0.2.1.16-rc speeds up performance for fast exit relays, and fixes
  a bunch of minor bugs.

  o Security fixes:
    - Fix an edge case where a malicious exit relay could convince a
      controller that the client's DNS question resolves to an internal IP
      address. Bug found and fixed by "optimist"; bugfix on 0.1.2.8-beta.

  o Major performance improvements (on 0.2.0.x):
    - Disable and refactor some debugging checks that forced a linear scan
      over the whole server-side DNS cache. These accounted for over 50%
      of CPU time on a relatively busy exit node's gprof profile. Found
      by Jacob.
    - Disable some debugging checks that appeared in exit node profile
      data.

  o Minor features:
    - Update to the "June 3 2009" ip-to-country file.
    - Do not have tor-resolve automatically refuse all .onion addresses;
      if AutomapHostsOnResolve is set in your torrc, this will work fine.

  o Minor bugfixes (on 0.2.0.x):
    - Log correct error messages for DNS-related network errors on
      Windows.
    - Fix a race condition that could cause crashes or memory corruption
      when running as a server with a controller listening for log
      messages.
    - Avoid crashing when we have a policy specified in a DirPolicy or
      SocksPolicy or ReachableAddresses option with ports set on it,
      and we re-load the policy. May fix bug 996.
    - Hidden service clients didn't use a cached service descriptor that
      was older than 15 minutes, but wouldn't fetch a new one either,
      because there was already one in the cache. Now, fetch a v2
      descriptor unless the same descriptor was added to the cache within
      the last 15 minutes. Fixes bug 997; reported by Marcus Griep.

  o Minor bugfixes (on 0.2.1.x):
    - Don't warn users about low port and hibernation mix when they
      provide a *ListenAddress directive to fix that. Bugfix on
      0.2.1.15-rc.
    - When switching back and forth between bridge mode, do not start
      gathering GeoIP data until two hours have passed.
    - Do not complain that the user has requested an excluded node as
      an exit when the node is not really an exit. This could happen
      because the circuit was for testing, or an introduction point.
      Fix for bug 984.


Changes in version 0.2.1.15-rc - 2009-05-25
  Tor 0.2.1.15-rc marks the second release candidate for the 0.2.1.x
  series. It fixes a major bug on fast exit relays, as well as a variety
  of more minor bugs.

  o Major bugfixes (on 0.2.0.x):
    - Fix a timing-dependent, allocator-dependent, DNS-related crash bug
      that would occur on some exit nodes when DNS failures and timeouts
      occurred in certain patterns. Fix for bug 957.

  o Minor bugfixes (on 0.2.0.x):
    - Actually return -1 in the error case for read_bandwidth_usage().
      Harmless bug, since we currently don't care about the return value
      anywhere. Bugfix on 0.2.0.9-alpha.
    - Provide a more useful log message if bug 977 (related to buffer
      freelists) ever reappears, and do not crash right away.
    - Fix an assertion failure on 64-bit platforms when we allocated
      memory right up to the end of a memarea, then realigned the memory
      one step beyond the end. Fixes a possible cause of bug 930.
    - Protect the count of open sockets with a mutex, so we can't
      corrupt it when two threads are closing or opening sockets at once.
      Fix for bug 939. Bugfix on 0.2.0.1-alpha.
    - Don't allow a bridge to publish its router descriptor to a
      non-bridge directory authority. Fixes part of bug 932.
    - When we change to or from being a bridge, reset our counts of
      client usage by country. Fixes bug 932.
    - Fix a bug that made stream bandwidth get misreported to the
      controller.
    - Stop using malloc_usable_size() to use more area than we had
      actually allocated: it was safe, but made valgrind really unhappy.
    - Fix a memory leak when v3 directory authorities load their keys
      and cert from disk. Bugfix on 0.2.0.1-alpha.

  o Minor bugfixes (on 0.2.1.x):
    - Fix use of freed memory when deciding to mark a non-addable
      descriptor as never-downloadable. Bugfix on 0.2.1.9-alpha.


Changes in version 0.2.1.14-rc - 2009-04-12
  Tor 0.2.1.14-rc marks the first release candidate for the 0.2.1.x
  series. It begins fixing some major performance problems, and also
  finally addresses the bug that was causing relays on dynamic IP
  addresses to fall out of the directory.

  o Major features:
    - Clients replace entry guards that were chosen more than a few months
      ago. This change should significantly improve client performance,
      especially once more people upgrade, since relays that have been
      a guard for a long time are currently overloaded.

  o Major bugfixes (on 0.2.0):
    - Finally fix the bug where dynamic-IP relays disappear when their
      IP address changes: directory mirrors were mistakenly telling
      them their old address if they asked via begin_dir, so they
      never got an accurate answer about their new address, so they
      just vanished after a day. For belt-and-suspenders, relays that
      don't set Address in their config now avoid using begin_dir for
      all direct connections. Should fix bugs 827, 883, and 900.
    - Relays were falling out of the networkstatus consensus for
      part of a day if they changed their local config but the
      authorities discarded their new descriptor as "not sufficiently
      different". Now directory authorities accept a descriptor as changed
      if bandwidthrate or bandwidthburst changed. Partial fix for bug 962;
      patch by Sebastian.
    - Avoid crashing in the presence of certain malformed descriptors.
      Found by lark, and by automated fuzzing.

  o Minor features:
    - When generating circuit events with verbose nicknames for
      controllers, try harder to look up nicknames for routers on a
      circuit. (Previously, we would look in the router descriptors we had
      for nicknames, but not in the consensus.) Partial fix for bug 941.
    - If the bridge config line doesn't specify a port, assume 443.
      This makes bridge lines a bit smaller and easier for users to
      understand.
    - Raise the minimum bandwidth to be a relay from 20000 bytes to 20480
      bytes (aka 20KB/s), to match our documentation. Also update
      directory authorities so they always assign the Fast flag to relays
      with 20KB/s of capacity. Now people running relays won't suddenly
      find themselves not seeing any use, if the network gets faster
      on average.
    - Update to the "April 3 2009" ip-to-country file.

  o Minor bugfixes:
    - Avoid trying to print raw memory to the logs when we decide to
      give up on downloading a given relay descriptor. Bugfix on
      0.2.1.9-alpha.
    - In tor-resolve, when the Tor client to use is specified by
      <hostname>:<port>, actually use the specified port rather than
      defaulting to 9050. Bugfix on 0.2.1.6-alpha.
    - Make directory usage recording work again. Bugfix on 0.2.1.6-alpha.
    - When starting with a cache over a few days old, do not leak
      memory for the obsolete router descriptors in it. Bugfix on
      0.2.0.33.
    - Avoid double-free on list of successfully uploaded hidden
      service discriptors. Fix for bug 948. Bugfix on 0.2.1.6-alpha.
    - Change memarea_strndup() implementation to work even when
      duplicating a string at the end of a page. This bug was
      harmless for now, but could have meant crashes later. Fix by
      lark. Bugfix on 0.2.1.1-alpha.
    - Limit uploaded directory documents to be 16M rather than 500K.
      The directory authorities were refusing v3 consensus votes from
      other authorities, since the votes are now 504K. Fixes bug 959;
      bugfix on 0.0.2pre17 (where we raised it from 50K to 500K ;).
    - Directory authorities should never send a 503 "busy" response to
      requests for votes or keys. Bugfix on 0.2.0.8-alpha; exposed by
      bug 959.


Changes in version 0.2.1.13-alpha - 2009-03-09
  Tor 0.2.1.13-alpha includes another big pile of minor bugfixes and
  cleanups. We're finally getting close to a release candidate.

  o Major bugfixes:
    - Correctly update the list of which countries we exclude as
      exits, when the GeoIP file is loaded or reloaded. Diagnosed by
      lark. Bugfix on 0.2.1.6-alpha.

  o Minor bugfixes (on 0.2.0.x and earlier):
    - Automatically detect MacOSX versions earlier than 10.4.0, and
      disable kqueue from inside Tor when running with these versions.
      We previously did this from the startup script, but that was no
      help to people who didn't use the startup script. Resolves bug 863.
    - When we had picked an exit node for a connection, but marked it as
      "optional", and it turned out we had no onion key for the exit,
      stop wanting that exit and try again. This situation may not
      be possible now, but will probably become feasible with proposal
      158. Spotted by rovv. Fixes another case of bug 752.
    - Clients no longer cache certificates for authorities they do not
      recognize. Bugfix on 0.2.0.9-alpha.
    - When we can't transmit a DNS request due to a network error, retry
      it after a while, and eventually transmit a failing response to
      the RESOLVED cell. Bugfix on 0.1.2.5-alpha.
    - If the controller claimed responsibility for a stream, but that
      stream never finished making its connection, it would live
      forever in circuit_wait state. Now we close it after SocksTimeout
      seconds. Bugfix on 0.1.2.7-alpha; reported by Mike Perry.
    - Drop begin cells to a hidden service if they come from the middle
      of a circuit. Patch from lark.
    - When we erroneously receive two EXTEND cells for the same circuit
      ID on the same connection, drop the second. Patch from lark.
    - Fix a crash that occurs on exit nodes when a nameserver request
      timed out. Bugfix on 0.1.2.1-alpha; our CLEAR debugging code had
      been suppressing the bug since 0.1.2.10-alpha. Partial fix for
      bug 929.
    - Do not assume that a stack-allocated character array will be
      64-bit aligned on platforms that demand that uint64_t access is
      aligned. Possible fix for bug 604.
    - Parse dates and IPv4 addresses in a locale- and libc-independent
      manner, to avoid platform-dependent behavior on malformed input.
    - Build correctly when configured to build outside the main source
      path. Patch from Michael Gold.
    - We were already rejecting relay begin cells with destination port
      of 0. Now also reject extend cells with destination port or address
      of 0. Suggested by lark.

  o Minor bugfixes (on 0.2.1.x):
    - Don't re-extend introduction circuits if we ran out of RELAY_EARLY
      cells. Bugfix on 0.2.1.3-alpha. Fixes more of bug 878.
    - If we're an exit node, scrub the IP address to which we are exiting
      in the logs. Bugfix on 0.2.1.8-alpha.

  o Minor features:
    - On Linux, use the prctl call to re-enable core dumps when the user
      is option is set.
    - New controller event NEWCONSENSUS that lists the networkstatus
      lines for every recommended relay. Now controllers like Torflow
      can keep up-to-date on which relays they should be using.
    - Update to the "February 26 2009" ip-to-country file.


Changes in version 0.2.0.34 - 2009-02-08
  Tor 0.2.0.34 features several more security-related fixes. You should
  upgrade, especially if you run an exit relay (remote crash) or a
  directory authority (remote infinite loop), or you're on an older
  (pre-XP) or not-recently-patched Windows (remote exploit).

  This release marks end-of-life for Tor 0.1.2.x. Those Tor versions
  have many known flaws, and nobody should be using them. You should
  upgrade. If you're using a Linux or BSD and its packages are obsolete,
  stop using those packages and upgrade anyway.

  o Security fixes:
    - Fix an infinite-loop bug on handling corrupt votes under certain
      circumstances. Bugfix on 0.2.0.8-alpha.
    - Fix a temporary DoS vulnerability that could be performed by
      a directory mirror. Bugfix on 0.2.0.9-alpha; reported by lark.
    - Avoid a potential crash on exit nodes when processing malformed
      input. Remote DoS opportunity. Bugfix on 0.2.0.33.
    - Do not accept incomplete ipv4 addresses (like 192.168.0) as valid.
      Spec conformance issue. Bugfix on Tor 0.0.2pre27.

  o Minor bugfixes:
    - Fix compilation on systems where time_t is a 64-bit integer.
      Patch from Matthias Drochner.
    - Don't consider expiring already-closed client connections. Fixes
      bug 893. Bugfix on 0.0.2pre20.


Changes in version 0.2.1.12-alpha - 2009-02-08
  Tor 0.2.1.12-alpha features several more security-related fixes. You
  should upgrade, especially if you run an exit relay (remote crash) or
  a directory authority (remote infinite loop), or you're on an older
  (pre-XP) or not-recently-patched Windows (remote exploit). It also
  includes a big pile of minor bugfixes and cleanups.

  o Security fixes:
    - Fix an infinite-loop bug on handling corrupt votes under certain
      circumstances. Bugfix on 0.2.0.8-alpha.
    - Fix a temporary DoS vulnerability that could be performed by
      a directory mirror. Bugfix on 0.2.0.9-alpha; reported by lark.
    - Avoid a potential crash on exit nodes when processing malformed
      input. Remote DoS opportunity. Bugfix on 0.2.1.7-alpha.

  o Minor bugfixes:
    - Let controllers actually ask for the "clients_seen" event for
      getting usage summaries on bridge relays. Bugfix on 0.2.1.10-alpha;
      reported by Matt Edman.
    - Fix a compile warning on OSX Panther. Fixes bug 913; bugfix against
      0.2.1.11-alpha.
    - Fix a bug in address parsing that was preventing bridges or hidden
      service targets from being at IPv6 addresses.
    - Solve a bug that kept hardware crypto acceleration from getting
      enabled when accounting was turned on. Fixes bug 907. Bugfix on
      0.0.9pre6.
    - Remove a bash-ism from configure.in to build properly on non-Linux
      platforms. Bugfix on 0.2.1.1-alpha.
    - Fix code so authorities _actually_ send back X-Descriptor-Not-New
      headers. Bugfix on 0.2.0.10-alpha.
    - Don't consider expiring already-closed client connections. Fixes
      bug 893. Bugfix on 0.0.2pre20.
    - Fix another interesting corner-case of bug 891 spotted by rovv:
      Previously, if two hosts had different amounts of clock drift, and
      one of them created a new connection with just the wrong timing,
      the other might decide to deprecate the new connection erroneously.
      Bugfix on 0.1.1.13-alpha.
    - Resolve a very rare crash bug that could occur when the user forced
      a nameserver reconfiguration during the middle of a nameserver
      probe. Fixes bug 526. Bugfix on 0.1.2.1-alpha.
    - Support changing value of ServerDNSRandomizeCase during SIGHUP.
      Bugfix on 0.2.1.7-alpha.
    - If we're using bridges and our network goes away, be more willing
      to forgive our bridges and try again when we get an application
      request. Bugfix on 0.2.0.x.

  o Minor features:
    - Support platforms where time_t is 64 bits long. (Congratulations,
      NetBSD!) Patch from Matthias Drochner.
    - Add a 'getinfo status/clients-seen' controller command, in case
      controllers want to hear clients_seen events but connect late.

  o Build changes:
    - Disable GCC's strict alias optimization by default, to avoid the
      likelihood of its introducing subtle bugs whenever our code violates
      the letter of C99's alias rules.


Changes in version 0.2.0.33 - 2009-01-21
  Tor 0.2.0.33 fixes a variety of bugs that were making relays less
  useful to users. It also finally fixes a bug where a relay or client
  that's been off for many days would take a long time to bootstrap.

  This update also fixes an important security-related bug reported by
  Ilja van Sprundel. You should upgrade. (We'll send out more details
  about the bug once people have had some time to upgrade.)

  o Security fixes:
    - Fix a heap-corruption bug that may be remotely triggerable on
      some platforms. Reported by Ilja van Sprundel.

  o Major bugfixes:
    - When a stream at an exit relay is in state "resolving" or
      "connecting" and it receives an "end" relay cell, the exit relay
      would silently ignore the end cell and not close the stream. If
      the client never closes the circuit, then the exit relay never
      closes the TCP connection. Bug introduced in Tor 0.1.2.1-alpha;
      reported by "wood".
    - When sending CREATED cells back for a given circuit, use a 64-bit
      connection ID to find the right connection, rather than an addr:port
      combination. Now that we can have multiple OR connections between
      the same ORs, it is no longer possible to use addr:port to uniquely
      identify a connection.
    - Bridge relays that had DirPort set to 0 would stop fetching
      descriptors shortly after startup, and then briefly resume
      after a new bandwidth test and/or after publishing a new bridge
      descriptor. Bridge users that try to bootstrap from them would
      get a recent networkstatus but would get descriptors from up to
      18 hours earlier, meaning most of the descriptors were obsolete
      already. Reported by Tas; bugfix on 0.2.0.13-alpha.
    - Prevent bridge relays from serving their 'extrainfo' document
      to anybody who asks, now that extrainfo docs include potentially
      sensitive aggregated client geoip summaries. Bugfix on
      0.2.0.13-alpha.
    - If the cached networkstatus consensus is more than five days old,
      discard it rather than trying to use it. In theory it could be
      useful because it lists alternate directory mirrors, but in practice
      it just means we spend many minutes trying directory mirrors that
      are long gone from the network. Also discard router descriptors as
      we load them if they are more than five days old, since the onion
      key is probably wrong by now. Bugfix on 0.2.0.x. Fixes bug 887.

  o Minor bugfixes:
    - Do not mark smartlist_bsearch_idx() function as ATTR_PURE. This bug
      could make gcc generate non-functional binary search code. Bugfix
      on 0.2.0.10-alpha.
    - Build correctly on platforms without socklen_t.
    - Compile without warnings on solaris.
    - Avoid potential crash on internal error during signature collection.
      Fixes bug 864. Patch from rovv.
    - Correct handling of possible malformed authority signing key
      certificates with internal signature types. Fixes bug 880.
      Bugfix on 0.2.0.3-alpha.
    - Fix a hard-to-trigger resource leak when logging credential status.
      CID 349.
    - When we can't initialize DNS because the network is down, do not
      automatically stop Tor from starting. Instead, we retry failed
      dns_init() every 10 minutes, and change the exit policy to reject
      *:* until one succeeds. Fixes bug 691.
    - Use 64 bits instead of 32 bits for connection identifiers used with
      the controller protocol, to greatly reduce risk of identifier reuse.
    - When we're choosing an exit node for a circuit, and we have
      no pending streams, choose a good general exit rather than one that
      supports "all the pending streams". Bugfix on 0.1.1.x. Fix by rovv.
    - Fix another case of assuming, when a specific exit is requested,
      that we know more than the user about what hosts it allows.
      Fixes one case of bug 752. Patch from rovv.
    - Clip the MaxCircuitDirtiness config option to a minimum of 10
      seconds. Warn the user if lower values are given in the
      configuration. Bugfix on 0.1.0.1-rc. Patch by Sebastian.
    - Clip the CircuitBuildTimeout to a minimum of 30 seconds. Warn the
      user if lower values are given in the configuration. Bugfix on
      0.1.1.17-rc. Patch by Sebastian.
    - Fix a memory leak when we decline to add a v2 rendezvous descriptor to
      the cache because we already had a v0 descriptor with the same ID.
      Bugfix on 0.2.0.18-alpha.
    - Fix a race condition when freeing keys shared between main thread
      and CPU workers that could result in a memory leak. Bugfix on
      0.1.0.1-rc. Fixes bug 889.
    - Send a valid END cell back when a client tries to connect to a
      nonexistent hidden service port. Bugfix on 0.1.2.15. Fixes bug
      840. Patch from rovv.
    - Check which hops rendezvous stream cells are associated with to
      prevent possible guess-the-streamid injection attacks from
      intermediate hops. Fixes another case of bug 446. Based on patch
      from rovv.
    - If a broken client asks a non-exit router to connect somewhere,
      do not even do the DNS lookup before rejecting the connection.
      Fixes another case of bug 619. Patch from rovv.
    - When a relay gets a create cell it can't decrypt (e.g. because it's
      using the wrong onion key), we were dropping it and letting the
      client time out. Now actually answer with a destroy cell. Fixes
      bug 904. Bugfix on 0.0.2pre8.

  o Minor bugfixes (hidden services):
    - Do not throw away existing introduction points on SIGHUP. Bugfix on
      0.0.6pre1. Patch by Karsten. Fixes bug 874.

  o Minor features:
    - Report the case where all signatures in a detached set are rejected
      differently than the case where there is an error handling the
      detached set.
    - When we realize that another process has modified our cached
      descriptors, print out a more useful error message rather than
      triggering an assertion. Fixes bug 885. Patch from Karsten.
    - Implement the 0x20 hack to better resist DNS poisoning: set the
      case on outgoing DNS requests randomly, and reject responses that do
      not match the case correctly. This logic can be disabled with the
      ServerDNSRamdomizeCase setting, if you are using one of the 0.3%
      of servers that do not reliably preserve case in replies. See
      "Increased DNS Forgery Resistance through 0x20-Bit Encoding"
      for more info.
    - Check DNS replies for more matching fields to better resist DNS
      poisoning.
    - Never use OpenSSL compression: it wastes RAM and CPU trying to
      compress cells, which are basically all encrypted, compressed, or
      both.


Changes in version 0.2.1.11-alpha - 2009-01-20
  Tor 0.2.1.11-alpha finishes fixing the "if your Tor is off for a
  week it will take a long time to bootstrap again" bug. It also fixes
  an important security-related bug reported by Ilja van Sprundel. You
  should upgrade. (We'll send out more details about the bug once people
  have had some time to upgrade.)

  o Security fixes:
    - Fix a heap-corruption bug that may be remotely triggerable on
      some platforms. Reported by Ilja van Sprundel.

  o Major bugfixes:
    - Discard router descriptors as we load them if they are more than
      five days old. Otherwise if Tor is off for a long time and then
      starts with cached descriptors, it will try to use the onion
      keys in those obsolete descriptors when building circuits. Bugfix
      on 0.2.0.x. Fixes bug 887.

  o Minor features:
    - Try to make sure that the version of Libevent we're running with
      is binary-compatible with the one we built with. May address bug
      897 and others.
    - Make setting ServerDNSRandomizeCase to 0 actually work. Bugfix
      for bug 905. Bugfix on 0.2.1.7-alpha.
    - Add a new --enable-local-appdata configuration switch to change
      the default location of the datadir on win32 from APPDATA to
      LOCAL_APPDATA. In the future, we should migrate to LOCAL_APPDATA
      entirely. Patch from coderman.

  o Minor bugfixes:
    - Make outbound DNS packets respect the OutboundBindAddress setting.
      Fixes the bug part of bug 798. Bugfix on 0.1.2.2-alpha.
    - When our circuit fails at the first hop (e.g. we get a destroy
      cell back), avoid using that OR connection anymore, and also
      tell all the one-hop directory requests waiting for it that they
      should fail. Bugfix on 0.2.1.3-alpha.
    - In the torify(1) manpage, mention that tsocks will leak your
      DNS requests.


Changes in version 0.2.1.10-alpha - 2009-01-06
  Tor 0.2.1.10-alpha fixes two major bugs in bridge relays (one that
  would make the bridge relay not so useful if it had DirPort set to 0,
  and one that could let an attacker learn a little bit of information
  about the bridge's users), and a bug that would cause your Tor relay
  to ignore a circuit create request it can't decrypt (rather than reply
  with an error). It also fixes a wide variety of other bugs.

  o Major bugfixes:
    - If the cached networkstatus consensus is more than five days old,
      discard it rather than trying to use it. In theory it could
      be useful because it lists alternate directory mirrors, but in
      practice it just means we spend many minutes trying directory
      mirrors that are long gone from the network. Helps bug 887 a bit;
      bugfix on 0.2.0.x.
    - Bridge relays that had DirPort set to 0 would stop fetching
      descriptors shortly after startup, and then briefly resume
      after a new bandwidth test and/or after publishing a new bridge
      descriptor. Bridge users that try to bootstrap from them would
      get a recent networkstatus but would get descriptors from up to
      18 hours earlier, meaning most of the descriptors were obsolete
      already. Reported by Tas; bugfix on 0.2.0.13-alpha.
    - Prevent bridge relays from serving their 'extrainfo' document
      to anybody who asks, now that extrainfo docs include potentially
      sensitive aggregated client geoip summaries. Bugfix on
      0.2.0.13-alpha.

  o Minor features:
    - New controller event "clients_seen" to report a geoip-based summary
      of which countries we've seen clients from recently. Now controllers
      like Vidalia can show bridge operators that they're actually making
      a difference.
    - Build correctly against versions of OpenSSL 0.9.8 or later built
      without support for deprecated functions.
    - Update to the "December 19 2008" ip-to-country file.

  o Minor bugfixes (on 0.2.0.x):
    - Authorities now vote for the Stable flag for any router whose
      weighted MTBF is at least 5 days, regardless of the mean MTBF.
    - Do not remove routers as too old if we do not have any consensus
      document. Bugfix on 0.2.0.7-alpha.
    - Do not accept incomplete ipv4 addresses (like 192.168.0) as valid.
      Spec conformance issue. Bugfix on Tor 0.0.2pre27.
    - When an exit relay resolves a stream address to a local IP address,
      do not just keep retrying that same exit relay over and
      over. Instead, just close the stream. Addresses bug 872. Bugfix
      on 0.2.0.32. Patch from rovv.
    - If a hidden service sends us an END cell, do not consider
      retrying the connection; just close it. Patch from rovv.
    - When we made bridge authorities stop serving bridge descriptors over
      unencrypted links, we also broke DirPort reachability testing for
      bridges. So bridges with a non-zero DirPort were printing spurious
      warns to their logs. Bugfix on 0.2.0.16-alpha. Fixes bug 709.
    - When a relay gets a create cell it can't decrypt (e.g. because it's
      using the wrong onion key), we were dropping it and letting the
      client time out. Now actually answer with a destroy cell. Fixes
      bug 904. Bugfix on 0.0.2pre8.
    - Squeeze 2-5% out of client performance (according to oprofile) by
      improving the implementation of some policy-manipulation functions.

  o Minor bugfixes (on 0.2.1.x):
    - Make get_interface_address() function work properly again; stop
      guessing the wrong parts of our address as our address.
    - Do not cannibalize a circuit if we're out of RELAY_EARLY cells to
      send on that circuit. Otherwise we might violate the proposal-110
      limit. Bugfix on 0.2.1.3-alpha. Partial fix for bug 878. Diagnosis
      thanks to Karsten.
    - When we're sending non-EXTEND cells to the first hop in a circuit,
      for example to use an encrypted directory connection, we don't need
      to use RELAY_EARLY cells: the first hop knows what kind of cell
      it is, and nobody else can even see the cell type. Conserving
      RELAY_EARLY cells makes it easier to cannibalize circuits like
      this later.
    - Stop logging nameserver addresses in reverse order.
    - If we are retrying a directory download slowly over and over, do
      not automatically give up after the 254th failure. Bugfix on
      0.2.1.9-alpha.
    - Resume reporting accurate "stream end" reasons to the local control
      port. They were lost in the changes for Proposal 148. Bugfix on
      0.2.1.9-alpha.

  o Deprecated and removed features:
    - The old "tor --version --version" command, which would print out
      the subversion "Id" of most of the source files, is now removed. It
      turned out to be less useful than we'd expected, and harder to
      maintain.

  o Code simplifications and refactoring:
    - Change our header file guard macros to be less likely to conflict
      with system headers. Adam Langley noticed that we were conflicting
      with log.h on Android.
    - Tool-assisted documentation cleanup. Nearly every function or
      static variable in Tor should have its own documentation now.


Changes in version 0.2.1.9-alpha - 2008-12-25
  Tor 0.2.1.9-alpha fixes many more bugs, some of them security-related.

  o New directory authorities:
    - gabelmoo (the authority run by Karsten Loesing) now has a new
      IP address.

  o Security fixes:
    - Never use a connection with a mismatched address to extend a
      circuit, unless that connection is canonical. A canonical
      connection is one whose address is authenticated by the router's
      identity key, either in a NETINFO cell or in a router descriptor.
    - Avoid a possible memory corruption bug when receiving hidden service
      descriptors. Bugfix on 0.2.1.6-alpha.

  o Major bugfixes:
    - Fix a logic error that would automatically reject all but the first
      configured DNS server. Bugfix on 0.2.1.5-alpha. Possible fix for
      part of bug 813/868. Bug spotted by coderman.
    - When a stream at an exit relay is in state "resolving" or
      "connecting" and it receives an "end" relay cell, the exit relay
      would silently ignore the end cell and not close the stream. If
      the client never closes the circuit, then the exit relay never
      closes the TCP connection. Bug introduced in 0.1.2.1-alpha;
      reported by "wood".
    - When we can't initialize DNS because the network is down, do not
      automatically stop Tor from starting. Instead, retry failed
      dns_init() every 10 minutes, and change the exit policy to reject
      *:* until one succeeds. Fixes bug 691.

  o Minor features:
    - Give a better error message when an overzealous init script says
      "sudo -u username tor --user username". Makes Bug 882 easier for
      users to diagnose.
    - When a directory authority gives us a new guess for our IP address,
      log which authority we used. Hopefully this will help us debug
      the recent complaints about bad IP address guesses.
    - Detect svn revision properly when we're using git-svn.
    - Try not to open more than one descriptor-downloading connection
      to an authority at once. This should reduce load on directory
      authorities. Fixes bug 366.
    - Add cross-certification to newly generated certificates, so that
      a signing key is enough information to look up a certificate.
      Partial implementation of proposal 157.
    - Start serving certificates by <identity digest, signing key digest>
      pairs. Partial implementation of proposal 157.
    - Clients now never report any stream end reason except 'MISC'.
      Implements proposal 148.
    - On platforms with a maximum syslog string length, truncate syslog
      messages to that length ourselves, rather than relying on the
      system to do it for us.
    - Optimize out calls to time(NULL) that occur for every IO operation,
      or for every cell. On systems where time() is a slow syscall,
      this fix will be slightly helpful.
    - Exit servers can now answer resolve requests for ip6.arpa addresses.
    - When we download a descriptor that we then immediately (as
      a directory authority) reject, do not retry downloading it right
      away. Should save some bandwidth on authorities. Fix for bug
      888. Patch by Sebastian Hahn.
    - When a download gets us zero good descriptors, do not notify
      Tor that new directory information has arrived.
    - Avoid some nasty corner cases in the logic for marking connections
      as too old or obsolete or noncanonical for circuits. Partial
      bugfix on bug 891.

  o Minor features (controller):
    - New CONSENSUS_ARRIVED event to note when a new consensus has
      been fetched and validated.
    - When we realize that another process has modified our cached
      descriptors file, print out a more useful error message rather
      than triggering an assertion. Fixes bug 885. Patch from Karsten.
    - Add an internal-use-only __ReloadTorrcOnSIGHUP option for
      controllers to prevent SIGHUP from reloading the
      configuration. Fixes bug 856.

  o Minor bugfixes:
    - Resume using the correct "REASON=" stream when telling the
      controller why we closed a stream. Bugfix in 0.2.1.1-alpha.
    - When a canonical connection appears later in our internal list
      than a noncanonical one for a given OR ID, always use the
      canonical one. Bugfix on 0.2.0.12-alpha. Fixes bug 805.
      Spotted by rovv.
    - Clip the MaxCircuitDirtiness config option to a minimum of 10
      seconds. Warn the user if lower values are given in the
      configuration. Bugfix on 0.1.0.1-rc. Patch by Sebastian.
    - Clip the CircuitBuildTimeout to a minimum of 30 seconds. Warn the
      user if lower values are given in the configuration. Bugfix on
      0.1.1.17-rc. Patch by Sebastian.
    - Fix a race condition when freeing keys shared between main thread
      and CPU workers that could result in a memory leak. Bugfix on
      0.1.0.1-rc. Fixes bug 889.

  o Minor bugfixes (hidden services):
    - Do not throw away existing introduction points on SIGHUP (bugfix on
      0.0.6pre1); also, do not stall hidden services because we're
      throwing away introduction points; bugfix on 0.2.1.7-alpha. Spotted
      by John Brooks. Patch by Karsten. Fixes bug 874.
    - Fix a memory leak when we decline to add a v2 rendezvous
      descriptor to the cache because we already had a v0 descriptor
      with the same ID. Bugfix on 0.2.0.18-alpha.

  o Deprecated and removed features:
    - RedirectExits has been removed. It was deprecated since
      0.2.0.3-alpha.
    - Finally remove deprecated "EXTENDED_FORMAT" controller feature. It
      has been called EXTENDED_EVENTS since 0.1.2.4-alpha.
    - Cell pools are now always enabled; --disable-cell-pools is ignored.

  o Code simplifications and refactoring:
    - Rename the confusing or_is_obsolete field to the more appropriate
      is_bad_for_new_circs, and move it to or_connection_t where it
      belongs.
    - Move edge-only flags from connection_t to edge_connection_t: not
      only is this better coding, but on machines of plausible alignment,
      it should save 4-8 bytes per connection_t. "Every little bit helps."
    - Rename ServerDNSAllowBrokenResolvConf to ServerDNSAllowBrokenConfig
      for consistency; keep old option working for backward compatibility.
    - Simplify the code for finding connections to use for a circuit.


Changes in version 0.2.1.8-alpha - 2008-12-08
  Tor 0.2.1.8-alpha fixes some crash bugs in earlier alpha releases,
  builds better on unusual platforms like Solaris and old OS X, and
  fixes a variety of other issues.

  o Major features:
    - New DirPortFrontPage option that takes an html file and publishes
      it as "/" on the DirPort. Now relay operators can provide a
      disclaimer without needing to set up a separate webserver. There's
      a sample disclaimer in contrib/tor-exit-notice.html.

  o Security fixes:
    - When the client is choosing entry guards, now it selects at most
      one guard from a given relay family. Otherwise we could end up with
      all of our entry points into the network run by the same operator.
      Suggested by Camilo Viecco. Fix on 0.1.1.11-alpha.

  o Major bugfixes:
    - Fix a DOS opportunity during the voting signature collection process
      at directory authorities. Spotted by rovv. Bugfix on 0.2.0.x.
    - Fix a possible segfault when establishing an exit connection. Bugfix
      on 0.2.1.5-alpha.

  o Minor bugfixes:
    - Get file locking working on win32. Bugfix on 0.2.1.6-alpha. Fixes
      bug 859.
    - Made Tor a little less aggressive about deleting expired
      certificates. Partial fix for bug 854.
    - Stop doing unaligned memory access that generated bus errors on
      sparc64. Bugfix on 0.2.0.10-alpha. Fix for bug 862.
    - Fix a crash bug when changing EntryNodes from the controller. Bugfix
      on 0.2.1.6-alpha. Fix for bug 867. Patched by Sebastian.
    - Make USR2 log-level switch take effect immediately. Bugfix on
      0.1.2.8-beta.
    - If one win32 nameserver fails to get added, continue adding the
      rest, and don't automatically fail.
    - Use fcntl() for locking when flock() is not available. Should fix
      compilation on Solaris. Should fix Bug 873. Bugfix on 0.2.1.6-alpha.
    - Do not mark smartlist_bsearch_idx() function as ATTR_PURE. This bug
      could make gcc generate non-functional binary search code. Bugfix
      on 0.2.0.10-alpha.
    - Build correctly on platforms without socklen_t.
    - Avoid potential crash on internal error during signature collection.
      Fixes bug 864. Patch from rovv.
    - Do not use C's stdio library for writing to log files. This will
      improve logging performance by a minute amount, and will stop
      leaking fds when our disk is full. Fixes bug 861.
    - Stop erroneous use of O_APPEND in cases where we did not in fact
      want to re-seek to the end of a file before every last write().
    - Correct handling of possible malformed authority signing key
      certificates with internal signature types. Fixes bug 880. Bugfix
      on 0.2.0.3-alpha.
    - Fix a hard-to-trigger resource leak when logging credential status.
      CID 349.

  o Minor features:
    - Directory mirrors no longer fetch the v1 directory or
      running-routers files. They are obsolete, and nobody asks for them
      anymore. This is the first step to making v1 authorities obsolete.

  o Minor features (controller):
    - Return circuit purposes in response to GETINFO circuit-status. Fixes
      bug 858.


Changes in version 0.2.0.32 - 2008-11-20
  Tor 0.2.0.32 fixes a major security problem in Debian and Ubuntu
  packages (and maybe other packages) noticed by Theo de Raadt, fixes
  a smaller security flaw that might allow an attacker to access local
  services, further improves hidden service performance, and fixes a
  variety of other issues.

  o Security fixes:
    - The "User" and "Group" config options did not clear the
      supplementary group entries for the Tor process. The "User" option
      is now more robust, and we now set the groups to the specified
      user's primary group. The "Group" option is now ignored. For more
      detailed logging on credential switching, set CREDENTIAL_LOG_LEVEL
      in common/compat.c to LOG_NOTICE or higher. Patch by Jacob Appelbaum
      and Steven Murdoch. Bugfix on 0.0.2pre14. Fixes bug 848 and 857.
    - The "ClientDNSRejectInternalAddresses" config option wasn't being
      consistently obeyed: if an exit relay refuses a stream because its
      exit policy doesn't allow it, we would remember what IP address
      the relay said the destination address resolves to, even if it's
      an internal IP address. Bugfix on 0.2.0.7-alpha; patch by rovv.

  o Major bugfixes:
    - Fix a DOS opportunity during the voting signature collection process
      at directory authorities. Spotted by rovv. Bugfix on 0.2.0.x.

  o Major bugfixes (hidden services):
    - When fetching v0 and v2 rendezvous service descriptors in parallel,
      we were failing the whole hidden service request when the v0
      descriptor fetch fails, even if the v2 fetch is still pending and
      might succeed. Similarly, if the last v2 fetch fails, we were
      failing the whole hidden service request even if a v0 fetch is
      still pending. Fixes bug 814. Bugfix on 0.2.0.10-alpha.
    - When extending a circuit to a hidden service directory to upload a
      rendezvous descriptor using a BEGIN_DIR cell, almost 1/6 of all
      requests failed, because the router descriptor has not been
      downloaded yet. In these cases, do not attempt to upload the
      rendezvous descriptor, but wait until the router descriptor is
      downloaded and retry. Likewise, do not attempt to fetch a rendezvous
      descriptor from a hidden service directory for which the router
      descriptor has not yet been downloaded. Fixes bug 767. Bugfix
      on 0.2.0.10-alpha.

  o Minor bugfixes:
    - Fix several infrequent memory leaks spotted by Coverity.
    - When testing for libevent functions, set the LDFLAGS variable
      correctly. Found by Riastradh.
    - Avoid a bug where the FastFirstHopPK 0 option would keep Tor from
      bootstrapping with tunneled directory connections. Bugfix on
      0.1.2.5-alpha. Fixes bug 797. Found by Erwin Lam.
    - When asked to connect to A.B.exit:80, if we don't know the IP for A
      and we know that server B rejects most-but-not all connections to
      port 80, we would previously reject the connection. Now, we assume
      the user knows what they were asking for. Fixes bug 752. Bugfix
      on 0.0.9rc5. Diagnosed by BarkerJr.
    - If we overrun our per-second write limits a little, count this as
      having used up our write allocation for the second, and choke
      outgoing directory writes. Previously, we had only counted this when
      we had met our limits precisely. Fixes bug 824. Patch from by rovv.
      Bugfix on 0.2.0.x (??).
    - Remove the old v2 directory authority 'lefkada' from the default
      list. It has been gone for many months.
    - Stop doing unaligned memory access that generated bus errors on
      sparc64. Bugfix on 0.2.0.10-alpha. Fixes bug 862.
    - Make USR2 log-level switch take effect immediately. Bugfix on
      0.1.2.8-beta.

  o Minor bugfixes (controller):
    - Make DNS resolved events into "CLOSED", not "FAILED". Bugfix on
      0.1.2.5-alpha. Fix by Robert Hogan. Resolves bug 807.


Changes in version 0.2.1.7-alpha - 2008-11-08
  Tor 0.2.1.7-alpha fixes a major security problem in Debian and Ubuntu
  packages (and maybe other packages) noticed by Theo de Raadt, fixes
  a smaller security flaw that might allow an attacker to access local
  services, adds better defense against DNS poisoning attacks on exit
  relays, further improves hidden service performance, and fixes a
  variety of other issues.

  o Security fixes:
    - The "ClientDNSRejectInternalAddresses" config option wasn't being
      consistently obeyed: if an exit relay refuses a stream because its
      exit policy doesn't allow it, we would remember what IP address
      the relay said the destination address resolves to, even if it's
      an internal IP address. Bugfix on 0.2.0.7-alpha; patch by rovv.
    - The "User" and "Group" config options did not clear the
      supplementary group entries for the Tor process. The "User" option
      is now more robust, and we now set the groups to the specified
      user's primary group. The "Group" option is now ignored. For more
      detailed logging on credential switching, set CREDENTIAL_LOG_LEVEL
      in common/compat.c to LOG_NOTICE or higher. Patch by Jacob Appelbaum
      and Steven Murdoch. Bugfix on 0.0.2pre14. Fixes bug 848.
    - Do not use or believe expired v3 authority certificates. Patch
      from Karsten. Bugfix in 0.2.0.x. Fixes bug 851.

  o Minor features:
    - Now NodeFamily and MyFamily config options allow spaces in
      identity fingerprints, so it's easier to paste them in.
      Suggested by Lucky Green.
    - Implement the 0x20 hack to better resist DNS poisoning: set the
      case on outgoing DNS requests randomly, and reject responses that do
      not match the case correctly. This logic can be disabled with the
      ServerDNSRandomizeCase setting, if you are using one of the 0.3%
      of servers that do not reliably preserve case in replies. See
      "Increased DNS Forgery Resistance through 0x20-Bit Encoding"
      for more info.
    - Preserve case in replies to DNSPort requests in order to support
      the 0x20 hack for resisting DNS poisoning attacks.

  o Hidden service performance improvements:
    - When the client launches an introduction circuit, retry with a
      new circuit after 30 seconds rather than 60 seconds.
    - Launch a second client-side introduction circuit in parallel
      after a delay of 15 seconds (based on work by Christian Wilms).
    - Hidden services start out building five intro circuits rather
      than three, and when the first three finish they publish a service
      descriptor using those. Now we publish our service descriptor much
      faster after restart.

  o Minor bugfixes:
    - Minor fix in the warning messages when you're having problems
      bootstrapping; also, be more forgiving of bootstrap problems when
      we're still making incremental progress on a given bootstrap phase.
    - When we're choosing an exit node for a circuit, and we have
      no pending streams, choose a good general exit rather than one that
      supports "all the pending streams". Bugfix on 0.1.1.x. Fix by rovv.
    - Send a valid END cell back when a client tries to connect to a
      nonexistent hidden service port. Bugfix on 0.1.2.15. Fixes bug
      840. Patch from rovv.
    - If a broken client asks a non-exit router to connect somewhere,
      do not even do the DNS lookup before rejecting the connection.
      Fixes another case of bug 619. Patch from rovv.
    - Fix another case of assuming, when a specific exit is requested,
      that we know more than the user about what hosts it allows.
      Fixes another case of bug 752. Patch from rovv.
    - Check which hops rendezvous stream cells are associated with to
      prevent possible guess-the-streamid injection attacks from
      intermediate hops. Fixes another case of bug 446. Based on patch
      from rovv.
    - Avoid using a negative right-shift when comparing 32-bit
      addresses. Possible fix for bug 845 and bug 811.
    - Make the assert_circuit_ok() function work correctly on circuits that
      have already been marked for close.
    - Fix read-off-the-end-of-string error in unit tests when decoding
      introduction points.
    - Fix uninitialized size field for memory area allocation: may improve
      memory performance during directory parsing.
    - Treat duplicate certificate fetches as failures, so that we do
      not try to re-fetch an expired certificate over and over and over.
    - Do not say we're fetching a certificate when we'll in fact skip it
      because of a pending download.


Changes in version 0.2.1.6-alpha - 2008-09-30
  Tor 0.2.1.6-alpha further improves performance and robustness of
  hidden services, starts work on supporting per-country relay selection,
  and fixes a variety of smaller issues.

  o Major features:
    - Implement proposal 121: make it possible to build hidden services
      that only certain clients are allowed to connect to. This is
      enforced at several points, so that unauthorized clients are unable
      to send INTRODUCE cells to the service, or even (depending on the
      type of authentication) to learn introduction points. This feature
      raises the bar for certain kinds of active attacks against hidden
      services. Code by Karsten Loesing.
    - Relays now store and serve v2 hidden service descriptors by default,
      i.e., the new default value for HidServDirectoryV2 is 1. This is
      the last step in proposal 114, which aims to make hidden service
      lookups more reliable.
    - Start work to allow node restrictions to include country codes. The
      syntax to exclude nodes in a country with country code XX is
      "ExcludeNodes {XX}". Patch from Robert Hogan. It still needs some
      refinement to decide what config options should take priority if
      you ask to both use a particular node and exclude it.
    - Allow ExitNodes list to include IP ranges and country codes, just
      like the Exclude*Nodes lists. Patch from Robert Hogan.

  o Major bugfixes:
    - Fix a bug when parsing ports in tor_addr_port_parse() that caused
      Tor to fail to start if you had it configured to use a bridge
      relay. Fixes bug 809. Bugfix on 0.2.1.5-alpha.
    - When extending a circuit to a hidden service directory to upload a
      rendezvous descriptor using a BEGIN_DIR cell, almost 1/6 of all
      requests failed, because the router descriptor had not been
      downloaded yet. In these cases, we now wait until the router
      descriptor is downloaded, and then retry. Likewise, clients
      now skip over a hidden service directory if they don't yet have
      its router descriptor, rather than futilely requesting it and
      putting mysterious complaints in the logs. Fixes bug 767. Bugfix
      on 0.2.0.10-alpha.
    - When fetching v0 and v2 rendezvous service descriptors in parallel,
      we were failing the whole hidden service request when the v0
      descriptor fetch fails, even if the v2 fetch is still pending and
      might succeed. Similarly, if the last v2 fetch fails, we were
      failing the whole hidden service request even if a v0 fetch is
      still pending. Fixes bug 814. Bugfix on 0.2.0.10-alpha.
    - DNS replies need to have names matching their requests, but
      these names should be in the questions section, not necessarily
      in the answers section. Fixes bug 823. Bugfix on 0.2.1.5-alpha.

  o Minor features:
    - Update to the "September 1 2008" ip-to-country file.
    - Allow ports 465 and 587 in the default exit policy again. We had
      rejected them in 0.1.0.15, because back in 2005 they were commonly
      misconfigured and ended up as spam targets. We hear they are better
      locked down these days.
    - Use a lockfile to make sure that two Tor processes are not
      simultaneously running with the same datadir.
    - Serve the latest v3 networkstatus consensus via the control
      port. Use "getinfo dir/status-vote/current/consensus" to fetch it.
    - Better logging about stability/reliability calculations on directory
      servers.
    - Drop the requirement to have an open dir port for storing and
      serving v2 hidden service descriptors.
    - Directory authorities now serve a /tor/dbg-stability.txt URL to
      help debug WFU and MTBF calculations.
    - Implement most of Proposal 152: allow specialized servers to permit
      single-hop circuits, and clients to use those servers to build
      single-hop circuits when using a specialized controller. Patch
      from Josh Albrecht. Resolves feature request 768.
    - Add a -p option to tor-resolve for specifying the SOCKS port: some
      people find host:port too confusing.
    - Make TrackHostExit mappings expire a while after their last use, not
      after their creation. Patch from Robert Hogan.
    - Provide circuit purposes along with circuit events to the controller.

  o Minor bugfixes:
    - Fix compile on OpenBSD 4.4-current. Bugfix on 0.2.1.5-alpha.
      Reported by Tas.
    - Fixed some memory leaks -- some quite frequent, some almost
      impossible to trigger -- based on results from Coverity.
    - When testing for libevent functions, set the LDFLAGS variable
      correctly. Found by Riastradh.
    - Fix an assertion bug in parsing policy-related options; possible fix
      for bug 811.
    - Catch and report a few more bootstrapping failure cases when Tor
      fails to establish a TCP connection. Cleanup on 0.2.1.x.
    - Avoid a bug where the FastFirstHopPK 0 option would keep Tor from
      bootstrapping with tunneled directory connections. Bugfix on
      0.1.2.5-alpha. Fixes bug 797. Found by Erwin Lam.
    - When asked to connect to A.B.exit:80, if we don't know the IP for A
      and we know that server B rejects most-but-not all connections to
      port 80, we would previously reject the connection. Now, we assume
      the user knows what they were asking for. Fixes bug 752. Bugfix
      on 0.0.9rc5. Diagnosed by BarkerJr.
    - If we are not using BEGIN_DIR cells, don't attempt to contact hidden
      service directories if they have no advertised dir port. Bugfix
      on 0.2.0.10-alpha.
    - If we overrun our per-second write limits a little, count this as
      having used up our write allocation for the second, and choke
      outgoing directory writes. Previously, we had only counted this when
      we had met our limits precisely. Fixes bug 824. Patch by rovv.
      Bugfix on 0.2.0.x (??).
    - Avoid a "0 divided by 0" calculation when calculating router uptime
      at directory authorities. Bugfix on 0.2.0.8-alpha.
    - Make DNS resolved controller events into "CLOSED", not
      "FAILED". Bugfix on 0.1.2.5-alpha. Fix by Robert Hogan. Resolves
      bug 807.
    - Fix a bug where an unreachable relay would establish enough
      reachability testing circuits to do a bandwidth test -- if
      we already have a connection to the middle hop of the testing
      circuit, then it could establish the last hop by using the existing
      connection. Bugfix on 0.1.2.2-alpha, exposed when we made testing
      circuits no longer use entry guards in 0.2.1.3-alpha.
    - If we have correct permissions on $datadir, we complain to stdout
      and fail to start. But dangerous permissions on
      $datadir/cached-status/ would cause us to open a log and complain
      there. Now complain to stdout and fail to start in both cases. Fixes
      bug 820, reported by seeess.
    - Remove the old v2 directory authority 'lefkada' from the default
      list. It has been gone for many months.

  o Code simplifications and refactoring:
    - Revise the connection_new functions so that a more typesafe variant
      exists. This will work better with Coverity, and let us find any
      actual mistakes we're making here.
    - Refactor unit testing logic so that dmalloc can be used sensibly
      with unit tests to check for memory leaks.
    - Move all hidden-service related fields from connection and circuit
      structure to substructures: this way they won't eat so much memory.


Changes in version 0.2.0.31 - 2008-09-03
  Tor 0.2.0.31 addresses two potential anonymity issues, starts to fix
  a big bug we're seeing where in rare cases traffic from one Tor stream
  gets mixed into another stream, and fixes a variety of smaller issues.

  o Major bugfixes:
    - Make sure that two circuits can never exist on the same connection
      with the same circuit ID, even if one is marked for close. This
      is conceivably a bugfix for bug 779. Bugfix on 0.1.0.4-rc.
    - Relays now reject risky extend cells: if the extend cell includes
      a digest of all zeroes, or asks to extend back to the relay that
      sent the extend cell, tear down the circuit. Ideas suggested
      by rovv.
    - If not enough of our entry guards are available so we add a new
      one, we might use the new one even if it overlapped with the
      current circuit's exit relay (or its family). Anonymity bugfix
      pointed out by rovv.

  o Minor bugfixes:
    - Recover 3-7 bytes that were wasted per memory chunk. Fixes bug
      794; bug spotted by rovv. Bugfix on 0.2.0.1-alpha.
    - Correctly detect the presence of the linux/netfilter_ipv4.h header
      when building against recent kernels. Bugfix on 0.1.2.1-alpha.
    - Pick size of default geoip filename string correctly on windows.
      Fixes bug 806. Bugfix on 0.2.0.30.
    - Make the autoconf script accept the obsolete --with-ssl-dir
      option as an alias for the actually-working --with-openssl-dir
      option. Fix the help documentation to recommend --with-openssl-dir.
      Based on a patch by "Dave". Bugfix on 0.2.0.1-alpha.
    - When using the TransPort option on OpenBSD, and using the User
      option to change UID and drop privileges, make sure to open
      /dev/pf before dropping privileges. Fixes bug 782. Patch from
      Christopher Davis. Bugfix on 0.1.2.1-alpha.
    - Try to attach connections immediately upon receiving a RENDEZVOUS2
      or RENDEZVOUS_ESTABLISHED cell. This can save a second or two
      on the client side when connecting to a hidden service. Bugfix
      on 0.0.6pre1. Found and fixed by Christian Wilms; resolves bug 743.
    - When closing an application-side connection because its circuit is
      getting torn down, generate the stream event correctly. Bugfix on
      0.1.2.x. Anonymous patch.


Changes in version 0.2.1.5-alpha - 2008-08-31
  Tor 0.2.1.5-alpha moves us closer to handling IPv6 destinations, puts
  in a lot of the infrastructure for adding authorization to hidden
  services, lays the groundwork for having clients read their load
  balancing information out of the networkstatus consensus rather than
  the individual router descriptors, addresses two potential anonymity
  issues, and fixes a variety of smaller issues.

  o Major features:
    - Convert many internal address representations to optionally hold
      IPv6 addresses.
    - Generate and accept IPv6 addresses in many protocol elements.
    - Make resolver code handle nameservers located at ipv6 addresses.
    - Begin implementation of proposal 121 ("Client authorization for
      hidden services"): configure hidden services with client
      authorization, publish descriptors for them, and configure
      authorization data for hidden services at clients. The next
      step is to actually access hidden services that perform client
      authorization.
    - More progress toward proposal 141: Network status consensus
      documents and votes now contain bandwidth information for each
      router and a summary of that router's exit policy. Eventually this
      will be used by clients so that they do not have to download every
      known descriptor before building circuits.

  o Major bugfixes (on 0.2.0.x and before):
    - When sending CREATED cells back for a given circuit, use a 64-bit
      connection ID to find the right connection, rather than an addr:port
      combination. Now that we can have multiple OR connections between
      the same ORs, it is no longer possible to use addr:port to uniquely
      identify a connection.
    - Relays now reject risky extend cells: if the extend cell includes
      a digest of all zeroes, or asks to extend back to the relay that
      sent the extend cell, tear down the circuit. Ideas suggested
      by rovv.
    - If not enough of our entry guards are available so we add a new
      one, we might use the new one even if it overlapped with the
      current circuit's exit relay (or its family). Anonymity bugfix
      pointed out by rovv.

  o Minor bugfixes:
    - Recover 3-7 bytes that were wasted per memory chunk. Fixes bug
      794; bug spotted by rovv. Bugfix on 0.2.0.1-alpha.
    - When using the TransPort option on OpenBSD, and using the User
      option to change UID and drop privileges, make sure to open /dev/pf
      before dropping privileges. Fixes bug 782. Patch from Christopher
      Davis. Bugfix on 0.1.2.1-alpha.
    - Correctly detect the presence of the linux/netfilter_ipv4.h header
      when building against recent kernels. Bugfix on 0.1.2.1-alpha.
    - Add a missing safe_str() call for a debug log message.
    - Use 64 bits instead of 32 bits for connection identifiers used with
      the controller protocol, to greatly reduce risk of identifier reuse.
    - Make the autoconf script accept the obsolete --with-ssl-dir
      option as an alias for the actually-working --with-openssl-dir
      option. Fix the help documentation to recommend --with-openssl-dir.
      Based on a patch by "Dave". Bugfix on 0.2.0.1-alpha.

  o Minor features:
    - Rate-limit too-many-sockets messages: when they happen, they happen
      a lot. Resolves bug 748.
    - Resist DNS poisoning a little better by making sure that names in
      answer sections match.
    - Print the SOCKS5 error message string as well as the error code
      when a tor-resolve request fails. Patch from Jacob.


Changes in version 0.2.1.4-alpha - 2008-08-04
  Tor 0.2.1.4-alpha fixes a pair of crash bugs in 0.2.1.3-alpha.

  o Major bugfixes:
    - The address part of exit policies was not correctly written
      to router descriptors. This generated router descriptors that failed
      their self-checks. Noticed by phobos, fixed by Karsten. Bugfix
      on 0.2.1.3-alpha.
    - Tor triggered a false assert when extending a circuit to a relay
      but we already have a connection open to that relay. Noticed by
      phobos, fixed by Karsten. Bugfix on 0.2.1.3-alpha.

  o Minor bugfixes:
    - Fix a hidden service logging bug: in some edge cases, the router
      descriptor of a previously picked introduction point becomes
      obsolete and we need to give up on it rather than continually
      complaining that it has become obsolete. Observed by xiando. Bugfix
      on 0.2.1.3-alpha.

  o Removed features:
    - Take out the TestVia config option, since it was a workaround for
      a bug that was fixed in Tor 0.1.1.21.


Changes in version 0.2.1.3-alpha - 2008-08-03
  Tor 0.2.1.3-alpha implements most of the pieces to prevent
  infinite-length circuit attacks (see proposal 110); fixes a bug that
  might cause exit relays to corrupt streams they send back; allows
  address patterns (e.g. 255.128.0.0/16) to appear in ExcludeNodes and
  ExcludeExitNodes config options; and fixes a big pile of bugs.

  o Bootstrapping bugfixes (on 0.2.1.x-alpha):
    - Send a bootstrap problem "warn" event on the first problem if the
      reason is NO_ROUTE (that is, our network is down).

  o Major features:
    - Implement most of proposal 110: The first K cells to be sent
      along a circuit are marked as special "early" cells; only K "early"
      cells will be allowed. Once this code is universal, we can block
      certain kinds of DOS attack by requiring that EXTEND commands must
      be sent using an "early" cell.

  o Major bugfixes:
    - Try to attach connections immediately upon receiving a RENDEZVOUS2
      or RENDEZVOUS_ESTABLISHED cell. This can save a second or two
      on the client side when connecting to a hidden service. Bugfix
      on 0.0.6pre1. Found and fixed by Christian Wilms; resolves bug 743.
    - Ensure that two circuits can never exist on the same connection
      with the same circuit ID, even if one is marked for close. This
      is conceivably a bugfix for bug 779; fixes a bug on 0.1.0.4-rc.

  o Minor features:
    - When relays do their initial bandwidth measurement, don't limit
      to just our entry guards for the test circuits. Otherwise we tend
      to have multiple test circuits going through a single entry guard,
      which makes our bandwidth test less accurate. Fixes part of bug 654;
      patch contributed by Josh Albrecht.
    - Add an ExcludeExitNodes option so users can list a set of nodes
      that should be be excluded from the exit node position, but
      allowed elsewhere. Implements proposal 151.
    - Allow address patterns (e.g., 255.128.0.0/16) to appear in
      ExcludeNodes and ExcludeExitNodes lists.
    - Change the implementation of ExcludeNodes and ExcludeExitNodes to
      be more efficient. Formerly it was quadratic in the number of
      servers; now it should be linear. Fixes bug 509.
    - Save 16-22 bytes per open circuit by moving the n_addr, n_port,
      and n_conn_id_digest fields into a separate structure that's
      only needed when the circuit has not yet attached to an n_conn.

  o Minor bugfixes:
    - Change the contrib/tor.logrotate script so it makes the new
      logs as "_tor:_tor" rather than the default, which is generally
      "root:wheel". Fixes bug 676, reported by Serge Koksharov.
    - Stop using __attribute__((nonnull)) with GCC: it can give us useful
      warnings (occasionally), but it can also cause the compiler to
      eliminate error-checking code. Suggested by Peter Gutmann.
    - When a hidden service is giving up on an introduction point candidate
      that was not included in the last published rendezvous descriptor,
      don't reschedule publication of the next descriptor. Fixes bug 763.
      Bugfix on 0.0.9.3.
    - Mark RendNodes, RendExcludeNodes, HiddenServiceNodes, and
      HiddenServiceExcludeNodes as obsolete: they never worked properly,
      and nobody claims to be using them. Fixes bug 754. Bugfix on
      0.1.0.1-rc. Patch from Christian Wilms.
    - Fix a small alignment and memory-wasting bug on buffer chunks.
      Spotted by rovv.

  o Minor bugfixes (controller):
    - When closing an application-side connection because its circuit
      is getting torn down, generate the stream event correctly.
      Bugfix on 0.1.2.x. Anonymous patch.

  o Removed features:
    - Remove all backward-compatibility code to support relays running
      versions of Tor so old that they no longer work at all on the
      Tor network.


Changes in version 0.2.0.30 - 2008-07-15
  o Minor bugfixes:
    - Stop using __attribute__((nonnull)) with GCC: it can give us useful
      warnings (occasionally), but it can also cause the compiler to
      eliminate error-checking code. Suggested by Peter Gutmann.


Changes in version 0.2.0.29-rc - 2008-07-08
  Tor 0.2.0.29-rc fixes two big bugs with using bridges, fixes more
  hidden-service performance bugs, and fixes a bunch of smaller bugs.

  o Major bugfixes:
    - If you have more than one bridge but don't know their keys,
      you would only launch a request for the descriptor of the first one
      on your list. (Tor considered launching requests for the others, but
      found that it already had a connection on the way for $0000...0000
      so it didn't open another.) Bugfix on 0.2.0.x.
    - If you have more than one bridge but don't know their keys, and the
      connection to one of the bridges failed, you would cancel all
      pending bridge connections. (After all, they all have the same
      digest.) Bugfix on 0.2.0.x.
    - When a hidden service was trying to establish an introduction point,
      and Tor had built circuits preemptively for such purposes, we
      were ignoring all the preemptive circuits and launching a new one
      instead. Bugfix on 0.2.0.14-alpha.
    - When a hidden service was trying to establish an introduction point,
      and Tor *did* manage to reuse one of the preemptively built
      circuits, it didn't correctly remember which one it used,
      so it asked for another one soon after, until there were no
      more preemptive circuits, at which point it launched one from
      scratch. Bugfix on 0.0.9.x.
    - Make directory servers include the X-Your-Address-Is: http header in
      their responses even for begin_dir conns. Now clients who only
      ever use begin_dir connections still have a way to learn their IP
      address. Fixes bug 737; bugfix on 0.2.0.22-rc. Reported by goldy.

  o Minor bugfixes:
    - Fix a macro/CPP interaction that was confusing some compilers:
      some GCCs don't like #if/#endif pairs inside macro arguments.
      Fixes bug 707.
    - Fix macro collision between OpenSSL 0.9.8h and Windows headers.
      Fixes bug 704; fix from Steven Murdoch.
    - When opening /dev/null in finish_daemonize(), do not pass the
      O_CREAT flag. Fortify was complaining, and correctly so. Fixes
      bug 742; fix from Michael Scherer. Bugfix on 0.0.2pre19.
    - Correctly detect transparent proxy support on Linux hosts that
      require in.h to be included before netfilter_ipv4.h. Patch
      from coderman.
    - Disallow session resumption attempts during the renegotiation
      stage of the v2 handshake protocol. Clients should never be trying
      session resumption at this point, but apparently some did, in
      ways that caused the handshake to fail. Bugfix on 0.2.0.20-rc. Bug
      found by Geoff Goodell.


Changes in version 0.2.1.2-alpha - 2008-06-20
  Tor 0.2.1.2-alpha includes a new "TestingTorNetwork" config option to
  make it easier to set up your own private Tor network; fixes several
  big bugs with using more than one bridge relay; fixes a big bug with
  offering hidden services quickly after Tor starts; and uses a better
  API for reporting potential bootstrapping problems to the controller.

  o Major features:
    - New TestingTorNetwork config option to allow adjustment of
      previously constant values that, while reasonable, could slow
      bootstrapping. Implements proposal 135. Patch from Karsten.

  o Major bugfixes:
    - If you have more than one bridge but don't know their digests,
      you would only learn a request for the descriptor of the first one
      on your list. (Tor considered launching requests for the others, but
      found that it already had a connection on the way for $0000...0000
      so it didn't open another.) Bugfix on 0.2.0.x.
    - If you have more than one bridge but don't know their digests,
      and the connection to one of the bridges failed, you would cancel
      all pending bridge connections. (After all, they all have the
      same digest.) Bugfix on 0.2.0.x.
    - When establishing a hidden service, introduction points that
      originate from cannibalized circuits are completely ignored and not
      included in rendezvous service descriptors. This might be another
      reason for delay in making a hidden service available. Bugfix
      from long ago (0.0.9.x?)

  o Minor features:
    - Allow OpenSSL to use dynamic locks if it wants.
    - When building a consensus, do not include routers that are down.
      This will cut down 30% to 40% on consensus size. Implements
      proposal 138.
    - In directory authorities' approved-routers files, allow
      fingerprints with or without space.
    - Add a "GETINFO /status/bootstrap-phase" controller option, so the
      controller can query our current bootstrap state in case it attaches
      partway through and wants to catch up.
    - Send an initial "Starting" bootstrap status event, so we have a
      state to start out in.

  o Minor bugfixes:
    - Asking for a conditional consensus at .../consensus/<fingerprints>
      would crash a dirserver if it did not already have a
      consensus. Bugfix on 0.2.1.1-alpha.
    - Clean up some macro/CPP interactions: some GCC versions don't like
      #if/#endif pairs inside macro arguments. Fixes bug 707. Bugfix on
      0.2.0.x.

  o Bootstrapping bugfixes (on 0.2.1.1-alpha):
    - Directory authorities shouldn't complain about bootstrapping
      problems just because they do a lot of reachability testing and
      some of the connection attempts fail.
    - Start sending "count" and "recommendation" key/value pairs in
      bootstrap problem status events, so the controller can hear about
      problems even before Tor decides they're worth reporting for sure.
    - If you're using bridges, generate "bootstrap problem" warnings
      as soon as you run out of working bridges, rather than waiting
      for ten failures -- which will never happen if you have less than
      ten bridges.
    - If we close our OR connection because there's been a circuit
      pending on it for too long, we were telling our bootstrap status
      events "REASON=NONE". Now tell them "REASON=TIMEOUT".


Changes in version 0.2.1.1-alpha - 2008-06-13
  Tor 0.2.1.1-alpha fixes a lot of memory fragmentation problems that
  were making the Tor process bloat especially on Linux; makes our TLS
  handshake blend in better; sends "bootstrap phase" status events to
  the controller, so it can keep the user informed of progress (and
  problems) fetching directory information and establishing circuits;
  and adds a variety of smaller features.

  o Major features:
    - More work on making our TLS handshake blend in: modify the list
      of ciphers advertised by OpenSSL in client mode to even more
      closely resemble a common web browser. We cheat a little so that
      we can advertise ciphers that the locally installed OpenSSL doesn't
      know about.
    - Start sending "bootstrap phase" status events to the controller,
      so it can keep the user informed of progress fetching directory
      information and establishing circuits. Also inform the controller
      if we think we're stuck at a particular bootstrap phase. Implements
      proposal 137.
    - Resume using OpenSSL's RAND_poll() for better (and more portable)
      cross-platform entropy collection again. We used to use it, then
      stopped using it because of a bug that could crash systems that
      called RAND_poll when they had a lot of fds open. It looks like the
      bug got fixed in late 2006. Our new behavior is to call RAND_poll()
      at startup, and to call RAND_poll() when we reseed later only if
      we have a non-buggy OpenSSL version.

  o Major bugfixes:
    - When we choose to abandon a new entry guard because we think our
      older ones might be better, close any circuits pending on that
      new entry guard connection. This fix should make us recover much
      faster when our network is down and then comes back. Bugfix on
      0.1.2.8-beta; found by lodger.

  o Memory fixes and improvements:
    - Add a malloc_good_size implementation to OpenBSD_malloc_linux.c,
      to avoid unused RAM in buffer chunks and memory pools.
    - Speed up parsing and cut down on memory fragmentation by using
      stack-style allocations for parsing directory objects. Previously,
      this accounted for over 40% of allocations from within Tor's code
      on a typical directory cache.
    - Use a Bloom filter rather than a digest-based set to track which
      descriptors we need to keep around when we're cleaning out old
      router descriptors. This speeds up the computation significantly,
      and may reduce fragmentation.
    - Reduce the default smartlist size from 32 to 16; it turns out that
      most smartlists hold around 8-12 elements tops.
    - Make dumpstats() log the fullness and size of openssl-internal
      buffers.
    - If the user has applied the experimental SSL_MODE_RELEASE_BUFFERS
      patch to their OpenSSL, turn it on to save memory on servers. This
      patch will (with any luck) get included in a mainline distribution
      before too long.
    - Never use OpenSSL compression: it wastes RAM and CPU trying to
      compress cells, which are basically all encrypted, compressed,
      or both.

  o Minor bugfixes:
    - Stop reloading the router list from disk for no reason when we
      run out of reachable directory mirrors. Once upon a time reloading
      it would set the 'is_running' flag back to 1 for them. It hasn't
      done that for a long time.
    - In very rare situations new hidden service descriptors were
      published earlier than 30 seconds after the last change to the
      service. (We currently think that a hidden service descriptor
      that's been stable for 30 seconds is worth publishing.)

  o Minor features:
    - Allow separate log levels to be configured for different logging
      domains. For example, this allows one to log all notices, warnings,
      or errors, plus all memory management messages of level debug or
      higher, with: Log [MM] debug-err [*] notice-err file /var/log/tor.
    - Add a couple of extra warnings to --enable-gcc-warnings for GCC 4.3,
      and stop using a warning that had become unfixably verbose under
      GCC 4.3.
    - New --hush command-line option similar to --quiet. While --quiet
      disables all logging to the console on startup, --hush limits the
      output to messages of warning and error severity.
    - Servers support a new URL scheme for consensus downloads that
      allows the client to specify which authorities are trusted.
      The server then only sends the consensus if the client will trust
      it. Otherwise a 404 error is sent back. Clients use this
      new scheme when the server supports it (meaning it's running
      0.2.1.1-alpha or later). Implements proposal 134.
    - New configure/torrc options (--enable-geoip-stats,
      DirRecordUsageByCountry) to record how many IPs we've served
      directory info to in each country code, how many status documents
      total we've sent to each country code, and what share of the total
      directory requests we should expect to see.
    - Use the TLS1 hostname extension to more closely resemble browser
      behavior.
    - Lots of new unit tests.
    - Add a macro to implement the common pattern of iterating through
      two parallel lists in lockstep.


Changes in version 0.2.0.28-rc - 2008-06-13
  Tor 0.2.0.28-rc fixes an anonymity-related bug, fixes a hidden-service
  performance bug, and fixes a bunch of smaller bugs.

  o Anonymity fixes:
    - Fix a bug where, when we were choosing the 'end stream reason' to
      put in our relay end cell that we send to the exit relay, Tor
      clients on Windows were sometimes sending the wrong 'reason'. The
      anonymity problem is that exit relays may be able to guess whether
      the client is running Windows, thus helping partition the anonymity
      set. Down the road we should stop sending reasons to exit relays,
      or otherwise prevent future versions of this bug.

  o Major bugfixes:
    - While setting up a hidden service, some valid introduction circuits
      were overlooked and abandoned. This might be the reason for
      the long delay in making a hidden service available. Bugfix on
      0.2.0.14-alpha.

  o Minor features:
    - Update to the "June 9 2008" ip-to-country file.
    - Run 'make test' as part of 'make dist', so we stop releasing so
      many development snapshots that fail their unit tests.

  o Minor bugfixes:
    - When we're checking if we have enough dir info for each relay
      to begin establishing circuits, make sure that we actually have
      the descriptor listed in the consensus, not just any descriptor.
      Bugfix on 0.1.2.x.
    - Bridge relays no longer print "xx=0" in their extrainfo document
      for every single country code in the geoip db. Bugfix on
      0.2.0.27-rc.
    - Only warn when we fail to load the geoip file if we were planning to
      include geoip stats in our extrainfo document. Bugfix on 0.2.0.27-rc.
    - If we change our MaxAdvertisedBandwidth and then reload torrc,
      Tor won't realize it should publish a new relay descriptor. Fixes
      bug 688, reported by mfr. Bugfix on 0.1.2.x.
    - When we haven't had any application requests lately, don't bother
      logging that we have expired a bunch of descriptors. Bugfix
      on 0.1.2.x.
    - Make relay cells written on a connection count as non-padding when
      tracking how long a connection has been in use. Bugfix on
      0.2.0.1-alpha. Spotted by lodger.
    - Fix unit tests in 0.2.0.27-rc.
    - Fix compile on Windows.


Changes in version 0.2.0.27-rc - 2008-06-03
  Tor 0.2.0.27-rc adds a few features we left out of the earlier
  release candidates. In particular, we now include an IP-to-country
  GeoIP database, so controllers can easily look up what country a
  given relay is in, and so bridge relays can give us some sanitized
  summaries about which countries are making use of bridges. (See proposal
  126-geoip-fetching.txt for details.)

  o Major features:
    - Include an IP-to-country GeoIP file in the tarball, so bridge
      relays can report sanitized summaries of the usage they're seeing.

  o Minor features:
    - Add a "PURPOSE=" argument to "STREAM NEW" events, as suggested by
      Robert Hogan. Fixes the first part of bug 681.
    - Make bridge authorities never serve extrainfo docs.
    - Add support to detect Libevent versions in the 1.4.x series
      on mingw.
    - Fix build on gcc 4.3 with --enable-gcc-warnings set.
    - Include a new contrib/tor-exit-notice.html file that exit relay
      operators can put on their website to help reduce abuse queries.

  o Minor bugfixes:
    - When tunneling an encrypted directory connection, and its first
      circuit fails, do not leave it unattached and ask the controller
      to deal. Fixes the second part of bug 681.
    - Make bridge authorities correctly expire old extrainfo documents
      from time to time.


Changes in version 0.2.0.26-rc - 2008-05-13
  Tor 0.2.0.26-rc fixes a major security vulnerability caused by a bug
  in Debian's OpenSSL packages. All users running any 0.2.0.x version
  should upgrade, whether they're running Debian or not.

  o Major security fixes:
    - Use new V3 directory authority keys on the tor26, gabelmoo, and
      moria1 V3 directory authorities. The old keys were generated with
      a vulnerable version of Debian's OpenSSL package, and must be
      considered compromised. Other authorities' keys were not generated
      with an affected version of OpenSSL.

  o Major bugfixes:
    - List authority signatures as "unrecognized" based on DirServer
      lines, not on cert cache. Bugfix on 0.2.0.x.

  o Minor features:
    - Add a new V3AuthUseLegacyKey option to make it easier for
      authorities to change their identity keys if they have to.


Changes in version 0.2.0.25-rc - 2008-04-23
  Tor 0.2.0.25-rc makes Tor work again on OS X and certain BSDs.

  o Major bugfixes:
    - Remember to initialize threading before initializing logging.
      Otherwise, many BSD-family implementations will crash hard on
      startup. Fixes bug 671. Bugfix on 0.2.0.24-rc.

  o Minor bugfixes:
    - Authorities correctly free policies on bad servers on
      exit. Fixes bug 672. Bugfix on 0.2.0.x.


Changes in version 0.2.0.24-rc - 2008-04-22
  Tor 0.2.0.24-rc adds dizum (run by Alex de Joode) as the new sixth
  v3 directory authority, makes relays with dynamic IP addresses and no
  DirPort notice more quickly when their IP address changes, fixes a few
  rare crashes and memory leaks, and fixes a few other miscellaneous bugs.

  o New directory authorities:
    - Take lefkada out of the list of v3 directory authorities, since
      it has been down for months.
    - Set up dizum (run by Alex de Joode) as the new sixth v3 directory
      authority.

  o Major bugfixes:
    - Detect address changes more quickly on non-directory mirror
      relays. Bugfix on 0.2.0.18-alpha; fixes bug 652.

  o Minor features (security):
    - Reject requests for reverse-dns lookup of names that are in
      a private address space. Patch from lodger.
    - Non-exit relays no longer allow DNS requests. Fixes bug 619. Patch
      from lodger.

  o Minor bugfixes (crashes):
    - Avoid a rare assert that can trigger when Tor doesn't have much
      directory information yet and it tries to fetch a v2 hidden
      service descriptor. Fixes bug 651, reported by nwf.
    - Initialize log mutex before initializing dmalloc. Otherwise,
      running with dmalloc would crash. Bugfix on 0.2.0.x-alpha.
    - Use recursive pthread mutexes in order to avoid deadlock when
      logging debug-level messages to a controller. Bug spotted by nwf,
      bugfix on 0.2.0.16-alpha.

  o Minor bugfixes (resource management):
    - Keep address policies from leaking memory: start their refcount
      at 1, not 2. Bugfix on 0.2.0.16-alpha.
    - Free authority certificates on exit, so they don't look like memory
      leaks. Bugfix on 0.2.0.19-alpha.
    - Free static hashtables for policy maps and for TLS connections on
      shutdown, so they don't look like memory leaks. Bugfix on 0.2.0.x.
    - Avoid allocating extra space when computing consensuses on 64-bit
      platforms. Bug spotted by aakova.

  o Minor bugfixes (misc):
    - Do not read the configuration file when we've only been told to
      generate a password hash. Fixes bug 643. Bugfix on 0.0.9pre5. Fix
      based on patch from Sebastian Hahn.
    - Exit relays that are used as a client can now reach themselves
      using the .exit notation, rather than just launching an infinite
      pile of circuits. Fixes bug 641. Reported by Sebastian Hahn.
    - When attempting to open a logfile fails, tell us why.
    - Fix a dumb bug that was preventing us from knowing that we should
      preemptively build circuits to handle expected directory requests.
      Fixes bug 660. Bugfix on 0.1.2.x.
    - Warn less verbosely about clock skew from netinfo cells from
      untrusted sources. Fixes bug 663.
    - Make controller stream events for DNS requests more consistent,
      by adding "new stream" events for DNS requests, and removing
      spurious "stream closed" events" for cached reverse resolves.
      Patch from mwenge. Fixes bug 646.
    - Correctly notify one-hop connections when a circuit build has
      failed. Possible fix for bug 669. Found by lodger.


Changes in version 0.2.0.23-rc - 2008-03-24
  Tor 0.2.0.23-rc is the fourth release candidate for the 0.2.0 series. It
  makes bootstrapping faster if the first directory mirror you contact
  is down. The bundles also include the new Vidalia 0.1.2 release.

  o Major bugfixes:
    - When a tunneled directory request is made to a directory server
      that's down, notice after 30 seconds rather than 120 seconds. Also,
      fail any begindir streams that are pending on it, so they can
      retry elsewhere. This was causing multi-minute delays on bootstrap.


Changes in version 0.2.0.22-rc - 2008-03-18
  Tor 0.2.0.22-rc is the third release candidate for the 0.2.0 series. It
  enables encrypted directory connections by default for non-relays, fixes
  some broken TLS behavior we added in 0.2.0.20-rc, and resolves many
  other bugs. The bundles also include Vidalia 0.1.1 and Torbutton 1.1.17.

  o Major features:
    - Enable encrypted directory connections by default for non-relays,
      so censor tools that block Tor directory connections based on their
      plaintext patterns will no longer work. This means Tor works in
      certain censored countries by default again.

  o Major bugfixes:
    - Make sure servers always request certificates from clients during
      TLS renegotiation. Reported by lodger; bugfix on 0.2.0.20-rc.
    - Do not enter a CPU-eating loop when a connection is closed in
      the middle of client-side TLS renegotiation. Fixes bug 622. Bug
      diagnosed by lodger; bugfix on 0.2.0.20-rc.
    - Fix assertion failure that could occur when a blocked circuit
      became unblocked, and it had pending client DNS requests. Bugfix
      on 0.2.0.1-alpha. Fixes bug 632.

  o Minor bugfixes (on 0.1.2.x):
    - Generate "STATUS_SERVER" events rather than misspelled
      "STATUS_SEVER" events. Caught by mwenge.
    - When counting the number of bytes written on a TLS connection,
      look at the BIO actually used for writing to the network, not
      at the BIO used (sometimes) to buffer data for the network.
      Looking at different BIOs could result in write counts on the
      order of ULONG_MAX. Fixes bug 614.
    - On Windows, correctly detect errors when listing the contents of
      a directory. Fix from lodger.

  o Minor bugfixes (on 0.2.0.x):
    - Downgrade "sslv3 alert handshake failure" message to INFO.
    - If we set RelayBandwidthRate and RelayBandwidthBurst very high but
      left BandwidthRate and BandwidthBurst at the default, we would be
      silently limited by those defaults. Now raise them to match the
      RelayBandwidth* values.
    - Fix the SVK version detection logic to work correctly on a branch.
    - Make --enable-openbsd-malloc work correctly on Linux with alpha
      CPUs. Fixes bug 625.
    - Logging functions now check that the passed severity is sane.
    - Use proper log levels in the testsuite call of
      get_interface_address6().
    - When using a nonstandard malloc, do not use the platform values for
      HAVE_MALLOC_GOOD_SIZE or HAVE_MALLOC_USABLE_SIZE.
    - Make the openbsd malloc code use 8k pages on alpha CPUs and
      16k pages on ia64.
    - Detect mismatched page sizes when using --enable-openbsd-malloc.
    - Avoid double-marked-for-close warning when certain kinds of invalid
      .in-addr.arpa addresses are passed to the DNSPort. Part of a fix
      for bug 617. Bugfix on 0.2.0.1-alpha.
    - Make sure that the "NULL-means-reject *:*" convention is followed by
      all the policy manipulation functions, avoiding some possible crash
      bugs. Bug found by lodger. Bugfix on 0.2.0.16-alpha.
    - Fix the implementation of ClientDNSRejectInternalAddresses so that it
      actually works, and doesn't warn about every single reverse lookup.
      Fixes the other part of bug 617. Bugfix on 0.2.0.1-alpha.

  o Minor features:
    - Only log guard node status when guard node status has changed.
    - Downgrade the 3 most common "INFO" messages to "DEBUG". This will
      make "INFO" 75% less verbose.


Changes in version 0.2.0.21-rc - 2008-03-02
  Tor 0.2.0.21-rc is the second release candidate for the 0.2.0 series. It
  makes Tor work well with Vidalia again, fixes a rare assert bug,
  and fixes a pair of more minor bugs. The bundles also include Vidalia
  0.1.0 and Torbutton 1.1.16.

  o Major bugfixes:
    - The control port should declare that it requires password auth
      when HashedControlSessionPassword is set too. Patch from Matt Edman;
      bugfix on 0.2.0.20-rc. Fixes bug 615.
    - Downgrade assert in connection_buckets_decrement() to a log message.
      This may help us solve bug 614, and in any case will make its
      symptoms less severe. Bugfix on 0.2.0.20-rc. Reported by fredzupy.
    - We were sometimes miscounting the number of bytes read from the
      network, causing our rate limiting to not be followed exactly.
      Bugfix on 0.2.0.16-alpha. Reported by lodger.

  o Minor bugfixes:
    - Fix compilation with OpenSSL 0.9.8 and 0.9.8a. All other supported
      OpenSSL versions should have been working fine. Diagnosis and patch
      from lodger, Karsten Loesing, and Sebastian Hahn. Fixes bug 616.
      Bugfix on 0.2.0.20-rc.


Changes in version 0.2.0.20-rc - 2008-02-24
  Tor 0.2.0.20-rc is the first release candidate for the 0.2.0 series. It
  makes more progress towards normalizing Tor's TLS handshake, makes
  hidden services work better again, helps relays bootstrap if they don't
  know their IP address, adds optional support for linking in openbsd's
  allocator or tcmalloc, allows really fast relays to scale past 15000
  sockets, and fixes a bunch of minor bugs reported by Veracode.

  o Major features:
    - Enable the revised TLS handshake based on the one designed by
      Steven Murdoch in proposal 124, as revised in proposal 130. It
      includes version negotiation for OR connections as described in
      proposal 105. The new handshake is meant to be harder for censors
      to fingerprint, and it adds the ability to detect certain kinds of
      man-in-the-middle traffic analysis attacks. The version negotiation
      feature will allow us to improve Tor's link protocol more safely
      in the future.
    - Choose which bridge to use proportional to its advertised bandwidth,
      rather than uniformly at random. This should speed up Tor for
      bridge users. Also do this for people who set StrictEntryNodes.
    - When a TrackHostExits-chosen exit fails too many times in a row,
      stop using it. Bugfix on 0.1.2.x; fixes bug 437.

  o Major bugfixes:
    - Resolved problems with (re-)fetching hidden service descriptors.
      Patch from Karsten Loesing; fixes problems with 0.2.0.18-alpha
      and 0.2.0.19-alpha.
    - If we only ever used Tor for hidden service lookups or posts, we
      would stop building circuits and start refusing connections after
      24 hours, since we falsely believed that Tor was dormant. Reported
      by nwf; bugfix on 0.1.2.x.
    - Servers that don't know their own IP address should go to the
      authorities for their first directory fetch, even if their DirPort
      is off or if they don't know they're reachable yet. This will help
      them bootstrap better. Bugfix on 0.2.0.18-alpha; fixes bug 609.
    - When counting the number of open sockets, count not only the number
      of sockets we have received from the socket() call, but also
      the number we've gotten from accept() and socketpair(). This bug
      made us fail to count all sockets that we were using for incoming
      connections. Bugfix on 0.2.0.x.
    - Fix code used to find strings within buffers, when those strings
      are not in the first chunk of the buffer. Bugfix on 0.2.0.x.
    - Fix potential segfault when parsing HTTP headers. Bugfix on 0.2.0.x.
    - Add a new __HashedControlSessionPassword option for controllers
      to use for one-off session password hashes that shouldn't get
      saved to disk by SAVECONF --- Vidalia users were accumulating a
      pile of HashedControlPassword lines in their torrc files, one for
      each time they had restarted Tor and then clicked Save. Make Tor
      automatically convert "HashedControlPassword" to this new option but
      only when it's given on the command line. Partial fix for bug 586.

  o Minor features (performance):
    - Tune parameters for cell pool allocation to minimize amount of
      RAM overhead used.
    - Add OpenBSD malloc code from phk as an optional malloc
      replacement on Linux: some glibc libraries do very poorly
      with Tor's memory allocation patterns. Pass
      --enable-openbsd-malloc to get the replacement malloc code.
    - Add a --with-tcmalloc option to the configure script to link
      against tcmalloc (if present). Does not yet search for
      non-system include paths.
    - Stop imposing an arbitrary maximum on the number of file descriptors
      used for busy servers. Bug reported by Olaf Selke; patch from
      Sebastian Hahn.

  o Minor features (other):
    - When SafeLogging is disabled, log addresses along with all TLS
      errors.
    - When building with --enable-gcc-warnings, check for whether Apple's
      warning "-Wshorten-64-to-32" is available.
    - Add a --passphrase-fd argument to the tor-gencert command for
      scriptability.

  o Minor bugfixes (memory leaks and code problems):
    - We were leaking a file descriptor if Tor started with a zero-length
      cached-descriptors file. Patch by freddy77; bugfix on 0.1.2.
    - Detect size overflow in zlib code. Reported by Justin Ferguson and
      Dan Kaminsky.
    - We were comparing the raw BridgePassword entry with a base64'ed
      version of it, when handling a "/tor/networkstatus-bridges"
      directory request. Now compare correctly. Noticed by Veracode.
    - Recover from bad tracked-since value in MTBF-history file.
      Should fix bug 537.
    - Alter the code that tries to recover from unhandled write
      errors, to not try to flush onto a socket that's given us
      unhandled errors. Bugfix on 0.1.2.x.
    - Make Unix controlsockets work correctly on OpenBSD. Patch from
      tup. Bugfix on 0.2.0.3-alpha.

  o Minor bugfixes (other):
    - If we have an extra-info document for our server, always make
      it available on the control port, even if we haven't gotten
      a copy of it from an authority yet. Patch from mwenge.
    - Log the correct memory chunk sizes for empty RAM chunks in mempool.c.
    - Directory mirrors no longer include a guess at the client's IP
      address if the connection appears to be coming from the same /24
      network; it was producing too many wrong guesses.
    - Make the new hidden service code respect the SafeLogging setting.
      Bugfix on 0.2.0.x. Patch from Karsten.
    - When starting as an authority, do not overwrite all certificates
      cached from other authorities. Bugfix on 0.2.0.x. Fixes bug 606.
    - If we're trying to flush the last bytes on a connection (for
      example, when answering a directory request), reset the
      time-to-give-up timeout every time we manage to write something
      on the socket. Bugfix on 0.1.2.x.
    - Change the behavior of "getinfo status/good-server-descriptor"
      so it doesn't return failure when any authority disappears.
    - Even though the man page said that "TrackHostExits ." should
      work, nobody had ever implemented it. Bugfix on 0.1.0.x.
    - Report TLS "zero return" case as a "clean close" and "IO error"
      as a "close". Stop calling closes "unexpected closes": existing
      Tors don't use SSL_close(), so having a connection close without
      the TLS shutdown handshake is hardly unexpected.
    - Send NAMESERVER_STATUS messages for a single failed nameserver
      correctly.

  o Code simplifications and refactoring:
    - Remove the tor_strpartition function: its logic was confused,
      and it was only used for one thing that could be implemented far
      more easily.


Changes in version 0.2.0.19-alpha - 2008-02-09
  Tor 0.2.0.19-alpha makes more progress towards normalizing Tor's TLS
  handshake, makes path selection for relays more secure and IP address
  guessing more robust, and generally fixes a lot of bugs in preparation
  for calling the 0.2.0 branch stable.

  o Major features:
    - Do not include recognizeable strings in the commonname part of
      Tor's x509 certificates.

  o Major bugfixes:
    - If we're a relay, avoid picking ourselves as an introduction point,
      a rendezvous point, or as the final hop for internal circuits. Bug
      reported by taranis and lodger. Bugfix on 0.1.2.x.
    - Patch from "Andrew S. Lists" to catch when we contact a directory
      mirror at IP address X and he says we look like we're coming from
      IP address X. Bugfix on 0.1.2.x.

  o Minor features (security):
    - Be more paranoid about overwriting sensitive memory on free(),
      as a defensive programming tactic to ensure forward secrecy.

  o Minor features (directory authority):
    - Actually validate the options passed to AuthDirReject,
      AuthDirInvalid, AuthDirBadDir, and AuthDirBadExit.
    - Reject router descriptors with out-of-range bandwidthcapacity or
      bandwidthburst values.

  o Minor features (controller):
    - Reject controller commands over 1MB in length. This keeps rogue
      processes from running us out of memory.

  o Minor features (misc):
    - Give more descriptive well-formedness errors for out-of-range
      hidden service descriptor/protocol versions.
    - Make memory debugging information describe more about history
      of cell allocation, so we can help reduce our memory use.

  o Deprecated features (controller):
    - The status/version/num-versioning and status/version/num-concurring
      GETINFO options are no longer useful in the v3 directory protocol:
      treat them as deprecated, and warn when they're used.

  o Minor bugfixes:
    - When our consensus networkstatus has been expired for a while, stop
      being willing to build circuits using it. Fixes bug 401. Bugfix
      on 0.1.2.x.
    - Directory caches now fetch certificates from all authorities
      listed in a networkstatus consensus, even when they do not
      recognize them. Fixes bug 571. Bugfix on 0.2.0.x.
    - When connecting to a bridge without specifying its key, insert
      the connection into the identity-to-connection map as soon as
      a key is learned. Fixes bug 574. Bugfix on 0.2.0.x.
    - Detect versions of OS X where malloc_good_size() is present in the
      library but never actually declared. Resolves bug 587. Bugfix
      on 0.2.0.x.
    - Stop incorrectly truncating zlib responses to directory authority
      signature download requests. Fixes bug 593. Bugfix on 0.2.0.x.
    - Stop recommending that every server operator send mail to tor-ops.
      Resolves bug 597. Bugfix on 0.1.2.x.
    - Don't trigger an assert if we start a directory authority with a
      private IP address (like 127.0.0.1).
    - Avoid possible failures when generating a directory with routers
      with over-long versions strings, or too many flags set. Bugfix
      on 0.1.2.x.
    - If an attempt to launch a DNS resolve request over the control
      port fails because we have overrun the limit on the number of
      connections, tell the controller that the request has failed.
    - Avoid using too little bandwidth when our clock skips a few
      seconds. Bugfix on 0.1.2.x.
    - Fix shell error when warning about missing packages in configure
      script, on Fedora or Red Hat machines. Bugfix on 0.2.0.x.
    - Do not become confused when receiving a spurious VERSIONS-like
      cell from a confused v1 client. Bugfix on 0.2.0.x.
    - Re-fetch v2 (as well as v0) rendezvous descriptors when all
      introduction points for a hidden service have failed. Patch from
      Karsten Loesing. Bugfix on 0.2.0.x.

  o Code simplifications and refactoring:
    - Remove some needless generality from cpuworker code, for improved
      type-safety.
    - Stop overloading the circuit_t.onionskin field for both "onionskin
      from a CREATE cell that we are waiting for a cpuworker to be
      assigned" and "onionskin from an EXTEND cell that we are going to
      send to an OR as soon as we are connected". Might help with bug 600.
    - Add an in-place version of aes_crypt() so that we can avoid doing a
      needless memcpy() call on each cell payload.


Changes in version 0.2.0.18-alpha - 2008-01-25
  Tor 0.2.0.18-alpha adds a sixth v3 directory authority run by CCC,
  fixes a big memory leak in 0.2.0.17-alpha, and adds new config options
  that can warn or reject connections to ports generally associated with
  vulnerable-plaintext protocols.

  o New directory authorities:
    - Set up dannenberg (run by CCC) as the sixth v3 directory
      authority.

  o Major bugfixes:
    - Fix a major memory leak when attempting to use the v2 TLS
      handshake code. Bugfix on 0.2.0.x; fixes bug 589.
    - We accidentally enabled the under-development v2 TLS handshake
      code, which was causing log entries like "TLS error while
      renegotiating handshake". Disable it again. Resolves bug 590.
    - We were computing the wrong Content-Length: header for directory
      responses that need to be compressed on the fly, causing clients
      asking for those items to always fail. Bugfix on 0.2.0.x; partially
      fixes bug 593.

  o Major features:
    - Avoid going directly to the directory authorities even if you're a
      relay, if you haven't found yourself reachable yet or if you've
      decided not to advertise your dirport yet. Addresses bug 556.
    - If we've gone 12 hours since our last bandwidth check, and we
      estimate we have less than 50KB bandwidth capacity but we could
      handle more, do another bandwidth test.
    - New config options WarnPlaintextPorts and RejectPlaintextPorts so
      Tor can warn and/or refuse connections to ports commonly used with
      vulnerable-plaintext protocols. Currently we warn on ports 23,
      109, 110, and 143, but we don't reject any.

  o Minor bugfixes:
    - When we setconf ClientOnly to 1, close any current OR and Dir
      listeners. Reported by mwenge.
    - When we get a consensus that's been signed by more people than
      we expect, don't log about it; it's not a big deal. Reported
      by Kyle Williams.

  o Minor features:
    - Don't answer "/tor/networkstatus-bridges" directory requests if
      the request isn't encrypted.
    - Make "ClientOnly 1" config option disable directory ports too.
    - Patches from Karsten Loesing to make v2 hidden services more
      robust: work even when there aren't enough HSDir relays available;
      retry when a v2 rend desc fetch fails; but don't retry if we
      already have a usable v0 rend desc.


Changes in version 0.2.0.17-alpha - 2008-01-17
  Tor 0.2.0.17-alpha makes the tarball build cleanly again (whoops).

  o Compile fixes:
    - Make the tor-gencert man page get included correctly in the tarball.


Changes in version 0.2.0.16-alpha - 2008-01-17
  Tor 0.2.0.16-alpha adds a fifth v3 directory authority run by Karsten
  Loesing, and generally cleans up a lot of features and minor bugs.

  o New directory authorities:
    - Set up gabelmoo (run by Karsten Loesing) as the fifth v3 directory
      authority.

  o Major performance improvements:
    - Switch our old ring buffer implementation for one more like that
      used by free Unix kernels. The wasted space in a buffer with 1mb
      of data will now be more like 8k than 1mb. The new implementation
      also avoids realloc();realloc(); patterns that can contribute to
      memory fragmentation.

  o Minor features:
    - Configuration files now accept C-style strings as values. This
      helps encode characters not allowed in the current configuration
      file format, such as newline or #. Addresses bug 557.
    - Although we fixed bug 539 (where servers would send HTTP status 503
      responses _and_ send a body too), there are still servers out
      there that haven't upgraded. Therefore, make clients parse such
      bodies when they receive them.
    - When we're not serving v2 directory information, there is no reason
      to actually keep any around. Remove the obsolete files and directory
      on startup if they are very old and we aren't going to serve them.

  o Minor performance improvements:
    - Reference-count and share copies of address policy entries; only 5%
      of them were actually distinct.
    - Never walk through the list of logs if we know that no log is
      interested in a given message.

  o Minor bugfixes:
    - When an authority has not signed a consensus, do not try to
      download a nonexistent "certificate with key 00000000". Bugfix
      on 0.2.0.x. Fixes bug 569.
    - Fix a rare assert error when we're closing one of our threads:
      use a mutex to protect the list of logs, so we never write to the
      list as it's being freed. Bugfix on 0.1.2.x. Fixes the very rare
      bug 575, which is kind of the revenge of bug 222.
    - Patch from Karsten Loesing to complain less at both the client
      and the relay when a relay used to have the HSDir flag but doesn't
      anymore, and we try to upload a hidden service descriptor.
    - Stop leaking one cert per TLS context. Fixes bug 582. Bugfix on
      0.2.0.15-alpha.
    - Do not try to download missing certificates until we have tried
      to check our fallback consensus. Fixes bug 583.
    - Make bridges round reported GeoIP stats info up to the nearest
      estimate, not down. Now we can distinguish between "0 people from
      this country" and "1 person from this country".
    - Avoid a spurious free on base64 failure. Bugfix on 0.1.2.
    - Avoid possible segfault if key generation fails in
      crypto_pk_hybrid_encrypt. Bugfix on 0.2.0.
    - Avoid segfault in the case where a badly behaved v2 versioning
      directory sends a signed networkstatus with missing client-versions.
      Bugfix on 0.1.2.
    - Avoid segfaults on certain complex invocations of
      router_get_by_hexdigest(). Bugfix on 0.1.2.
    - Correct bad index on array access in parse_http_time(). Bugfix
      on 0.2.0.
    - Fix possible bug in vote generation when server versions are present
      but client versions are not.
    - Fix rare bug on REDIRECTSTREAM control command when called with no
      port set: it could erroneously report an error when none had
      happened.
    - Avoid bogus crash-prone, leak-prone tor_realloc when we're
      compressing large objects and find ourselves with more than 4k
      left over. Bugfix on 0.2.0.
    - Fix a small memory leak when setting up a hidden service.
    - Fix a few memory leaks that could in theory happen under bizarre
      error conditions.
    - Fix an assert if we post a general-purpose descriptor via the
      control port but that descriptor isn't mentioned in our current
      network consensus. Bug reported by Jon McLachlan; bugfix on
      0.2.0.9-alpha.

  o Minor features (controller):
    - Get NS events working again. Patch from tup.
    - The GETCONF command now escapes and quotes configuration values
      that don't otherwise fit into the torrc file.
    - The SETCONF command now handles quoted values correctly.

  o Minor features (directory authorities):
    - New configuration options to override default maximum number of
      servers allowed on a single IP address. This is important for
      running a test network on a single host.
    - Actually implement the -s option to tor-gencert.
    - Add a manual page for tor-gencert.

  o Minor features (bridges):
    - Bridge authorities no longer serve bridge descriptors over
      unencrypted connections.

  o Minor features (other):
    - Add hidden services and DNSPorts to the list of things that make
      Tor accept that it has running ports. Change starting Tor with no
      ports from a fatal error to a warning; we might change it back if
      this turns out to confuse anybody. Fixes bug 579.


Changes in version 0.1.2.19 - 2008-01-17
  Tor 0.1.2.19 fixes a huge memory leak on exit relays, makes the default
  exit policy a little bit more conservative so it's safer to run an
  exit relay on a home system, and fixes a variety of smaller issues.

  o Security fixes:
    - Exit policies now reject connections that are addressed to a
      relay's public (external) IP address too, unless
      ExitPolicyRejectPrivate is turned off. We do this because too
      many relays are running nearby to services that trust them based
      on network address.

  o Major bugfixes:
    - When the clock jumps forward a lot, do not allow the bandwidth
      buckets to become negative. Fixes bug 544.
    - Fix a memory leak on exit relays; we were leaking a cached_resolve_t
      on every successful resolve. Reported by Mike Perry.
    - Purge old entries from the "rephist" database and the hidden
      service descriptor database even when DirPort is zero.
    - Stop thinking that 0.1.2.x directory servers can handle "begin_dir"
      requests. Should ease bugs 406 and 419 where 0.1.2.x relays are
      crashing or mis-answering these requests.
    - When we decide to send a 503 response to a request for servers, do
      not then also send the server descriptors: this defeats the whole
      purpose. Fixes bug 539.

  o Minor bugfixes:
    - Changing the ExitPolicyRejectPrivate setting should cause us to
      rebuild our server descriptor.
    - Fix handling of hex nicknames when answering controller requests for
      networkstatus by name, or when deciding whether to warn about
      unknown routers in a config option. (Patch from mwenge.)
    - Fix a couple of hard-to-trigger autoconf problems that could result
      in really weird results on platforms whose sys/types.h files define
      nonstandard integer types.
    - Don't try to create the datadir when running --verify-config or
      --hash-password. Resolves bug 540.
    - If we were having problems getting a particular descriptor from the
      directory caches, and then we learned about a new descriptor for
      that router, we weren't resetting our failure count. Reported
      by lodger.
    - Although we fixed bug 539 (where servers would send HTTP status 503
      responses _and_ send a body too), there are still servers out there
      that haven't upgraded. Therefore, make clients parse such bodies
      when they receive them.
    - Run correctly on systems where rlim_t is larger than unsigned long.
      This includes some 64-bit systems.
    - Run correctly on platforms (like some versions of OS X 10.5) where
      the real limit for number of open files is OPEN_FILES, not rlim_max
      from getrlimit(RLIMIT_NOFILES).
    - Avoid a spurious free on base64 failure.
    - Avoid segfaults on certain complex invocations of
      router_get_by_hexdigest().
    - Fix rare bug on REDIRECTSTREAM control command when called with no
      port set: it could erroneously report an error when none had
      happened.


Changes in version 0.2.0.15-alpha - 2007-12-25
  Tor 0.2.0.14-alpha and 0.2.0.15-alpha fix a bunch of bugs with the
  features added in 0.2.0.13-alpha.

  o Major bugfixes:
    - Fix several remotely triggerable asserts based on DirPort requests
      for a v2 or v3 networkstatus object before we were prepared. This
      was particularly bad for 0.2.0.13 and later bridge relays, who
      would never have a v2 networkstatus and would thus always crash
      when used. Bugfixes on 0.2.0.x.
    - Estimate the v3 networkstatus size more accurately, rather than
      estimating it at zero bytes and giving it artificially high priority
      compared to other directory requests. Bugfix on 0.2.0.x.

  o Minor bugfixes:
    - Fix configure.in logic for cross-compilation.
    - When we load a bridge descriptor from the cache, and it was
      previously unreachable, mark it as retriable so we won't just
      ignore it. Also, try fetching a new copy immediately. Bugfixes
      on 0.2.0.13-alpha.
    - The bridge GeoIP stats were counting other relays, for example
      self-reachability and authority-reachability tests.

  o Minor features:
    - Support compilation to target iPhone; patch from cjacker huang.
      To build for iPhone, pass the --enable-iphone option to configure.


Changes in version 0.2.0.14-alpha - 2007-12-23
  o Major bugfixes:
    - Fix a crash on startup if you install Tor 0.2.0.13-alpha fresh
      without a datadirectory from a previous Tor install. Reported
      by Zax.
    - Fix a crash when we fetch a descriptor that turns out to be
      unexpected (it used to be in our networkstatus when we started
      fetching it, but it isn't in our current networkstatus), and we
      aren't using bridges. Bugfix on 0.2.0.x.
    - Fix a crash when accessing hidden services: it would work the first
      time you use a given introduction point for your service, but
      on subsequent requests we'd be using garbage memory. Fixed by
      Karsten Loesing. Bugfix on 0.2.0.13-alpha.
    - Fix a crash when we load a bridge descriptor from disk but we don't
      currently have a Bridge line for it in our torrc. Bugfix on
      0.2.0.13-alpha.

  o Major features:
    - If bridge authorities set BridgePassword, they will serve a
      snapshot of known bridge routerstatuses from their DirPort to
      anybody who knows that password. Unset by default.

  o Minor bugfixes:
    - Make the unit tests build again.
    - Make "GETINFO/desc-annotations/id/<OR digest>" actually work.
    - Make PublishServerDescriptor default to 1, so the default doesn't
      have to change as we invent new directory protocol versions.
    - Fix test for rlim_t on OSX 10.3: sys/resource.h doesn't want to
      be included unless sys/time.h is already included. Fixes
      bug 553. Bugfix on 0.2.0.x.
    - If we receive a general-purpose descriptor and then receive an
      identical bridge-purpose descriptor soon after, don't discard
      the next one as a duplicate.

  o Minor features:
    - If BridgeRelay is set to 1, then the default for
      PublishServerDescriptor is now "bridge" rather than "v2,v3".
    - If the user sets RelayBandwidthRate but doesn't set
      RelayBandwidthBurst, then make them equal rather than erroring out.


Changes in version 0.2.0.13-alpha - 2007-12-21
  Tor 0.2.0.13-alpha adds a fourth v3 directory authority run by Geoff
  Goodell, fixes many more bugs, and adds a lot of infrastructure for
  upcoming features.

  o New directory authorities:
    - Set up lefkada (run by Geoff Goodell) as the fourth v3 directory
      authority.

  o Major bugfixes:
    - Only update guard status (usable / not usable) once we have
      enough directory information. This was causing us to always pick
      two new guards on startup (bugfix on 0.2.0.9-alpha), and it was
      causing us to discard all our guards on startup if we hadn't been
      running for a few weeks (bugfix on 0.1.2.x). Fixes bug 448.
    - Purge old entries from the "rephist" database and the hidden
      service descriptor databases even when DirPort is zero. Bugfix
      on 0.1.2.x.
    - We were ignoring our RelayBandwidthRate for the first 30 seconds
      after opening a circuit -- even a relayed circuit. Bugfix on
      0.2.0.3-alpha.
    - Stop thinking that 0.1.2.x directory servers can handle "begin_dir"
      requests. Should ease bugs 406 and 419 where 0.1.2.x relays are
      crashing or mis-answering these types of requests.
    - Relays were publishing their server descriptor to v1 and v2
      directory authorities, but they didn't try publishing to v3-only
      authorities. Fix this; and also stop publishing to v1 authorities.
      Bugfix on 0.2.0.x.
    - When we were reading router descriptors from cache, we were ignoring
      the annotations -- so for example we were reading in bridge-purpose
      descriptors as general-purpose descriptors. Bugfix on 0.2.0.8-alpha.
    - When we decided to send a 503 response to a request for servers, we
      were then also sending the server descriptors: this defeats the
      whole purpose. Fixes bug 539; bugfix on 0.1.2.x.

  o Major features:
    - Bridge relays now behave like clients with respect to time
      intervals for downloading new consensus documents -- otherwise they
      stand out. Bridge users now wait until the end of the interval,
      so their bridge relay will be sure to have a new consensus document.
    - Three new config options (AlternateDirAuthority,
      AlternateBridgeAuthority, and AlternateHSAuthority) that let the
      user selectively replace the default directory authorities by type,
      rather than the all-or-nothing replacement that DirServer offers.
    - Tor can now be configured to read a GeoIP file from disk in one
      of two formats. This can be used by controllers to map IP addresses
      to countries. Eventually, it may support exit-by-country.
    - When possible, bridge relays remember which countries users
      are coming from, and report aggregate information in their
      extra-info documents, so that the bridge authorities can learn
      where Tor is blocked.
    - Bridge directory authorities now do reachability testing on the
      bridges they know. They provide router status summaries to the
      controller via "getinfo ns/purpose/bridge", and also dump summaries
      to a file periodically.
    - Stop fetching directory info so aggressively if your DirPort is
      on but your ORPort is off; stop fetching v2 dir info entirely.
      You can override these choices with the new FetchDirInfoEarly
      config option.

  o Minor bugfixes:
    - The fix in 0.2.0.12-alpha cleared the "hsdir" flag in v3 network
      consensus documents when there are too many relays at a single
      IP address. Now clear it in v2 network status documents too, and
      also clear it in routerinfo_t when the relay is no longer listed
      in the relevant networkstatus document.
    - Don't crash if we get an unexpected value for the
      PublishServerDescriptor config option. Reported by Matt Edman;
      bugfix on 0.2.0.9-alpha.
    - Our new v2 hidden service descriptor format allows descriptors
      that have no introduction points. But Tor crashed when we tried
      to build a descriptor with no intro points (and it would have
      crashed if we had tried to parse one). Bugfix on 0.2.0.x; patch
      by Karsten Loesing.
    - Fix building with dmalloc 5.5.2 with glibc.
    - Reject uploaded descriptors and extrainfo documents if they're
      huge. Otherwise we'll cache them all over the network and it'll
      clog everything up. Reported by Aljosha Judmayer.
    - Check for presence of s6_addr16 and s6_addr32 fields in in6_addr
      via autoconf. Should fix compile on solaris. Bugfix on 0.2.0.x.
    - When the DANGEROUS_VERSION controller status event told us we're
      running an obsolete version, it used the string "OLD" to describe
      it. Yet the "getinfo" interface used the string "OBSOLETE". Now use
      "OBSOLETE" in both cases. Bugfix on 0.1.2.x.
    - If we can't expand our list of entry guards (e.g. because we're
      using bridges or we have StrictEntryNodes set), don't mark relays
      down when they fail a directory request. Otherwise we're too quick
      to mark all our entry points down. Bugfix on 0.1.2.x.
    - Fix handling of hex nicknames when answering controller requests for
      networkstatus by name, or when deciding whether to warn about unknown
      routers in a config option. Bugfix on 0.1.2.x. (Patch from mwenge.)
    - Fix a couple of hard-to-trigger autoconf problems that could result
      in really weird results on platforms whose sys/types.h files define
      nonstandard integer types. Bugfix on 0.1.2.x.
    - Fix compilation with --disable-threads set. Bugfix on 0.2.0.x.
    - Don't crash on name lookup when we have no current consensus. Fixes
      bug 538; bugfix on 0.2.0.x.
    - Only Tors that want to mirror the v2 directory info should
      create the "cached-status" directory in their datadir. (All Tors
      used to create it.) Bugfix on 0.2.0.9-alpha.
    - Directory authorities should only automatically download Extra Info
      documents if they're v1, v2, or v3 authorities. Bugfix on 0.1.2.x.

  o Minor features:
    - On the USR1 signal, when dmalloc is in use, log the top 10 memory
      consumers. (We already do this on HUP.)
    - Authorities and caches fetch the v2 networkstatus documents
      less often, now that v3 is encouraged.
    - Add a new config option BridgeRelay that specifies you want to
      be a bridge relay. Right now the only difference is that it makes
      you answer begin_dir requests, and it makes you cache dir info,
      even if your DirPort isn't on.
    - Add "GETINFO/desc-annotations/id/<OR digest>" so controllers can
      ask about source, timestamp of arrival, purpose, etc. We need
      something like this to help Vidalia not do GeoIP lookups on bridge
      addresses.
    - Allow multiple HashedControlPassword config lines, to support
      multiple controller passwords.
    - Authorities now decide whether they're authoritative for a given
      router based on the router's purpose.
    - New config options AuthDirBadDir and AuthDirListBadDirs for
      authorities to mark certain relays as "bad directories" in the
      networkstatus documents. Also supports the "!baddir" directive in
      the approved-routers file.


Changes in version 0.2.0.12-alpha - 2007-11-16
  This twelfth development snapshot fixes some more build problems as
  well as a few minor bugs.

  o Compile fixes:
    - Make it build on OpenBSD again. Patch from tup.
    - Substitute BINDIR and LOCALSTATEDIR in scripts. Fixes
      package-building for Red Hat, OS X, etc.

  o Minor bugfixes (on 0.1.2.x):
    - Changing the ExitPolicyRejectPrivate setting should cause us to
      rebuild our server descriptor.

  o Minor bugfixes (on 0.2.0.x):
    - When we're lacking a consensus, don't try to perform rendezvous
      operations. Reported by Karsten Loesing.
    - Fix a small memory leak whenever we decide against using a
      newly picked entry guard. Reported by Mike Perry.
    - When authorities detected more than two relays running on the same
      IP address, they were clearing all the status flags but forgetting
      to clear the "hsdir" flag. So clients were being told that a
      given relay was the right choice for a v2 hsdir lookup, yet they
      never had its descriptor because it was marked as 'not running'
      in the consensus.
    - If we're trying to fetch a bridge descriptor and there's no way
      the bridge authority could help us (for example, we don't know
      a digest, or there is no bridge authority), don't be so eager to
      fall back to asking the bridge authority.
    - If we're using bridges or have strictentrynodes set, and our
      chosen exit is in the same family as all our bridges/entry guards,
      then be flexible about families.

  o Minor features:
    - When we negotiate a v2 link-layer connection (not yet implemented),
      accept RELAY_EARLY cells and turn them into RELAY cells if we've
      negotiated a v1 connection for their next step. Initial code for
      proposal 110.


Changes in version 0.2.0.11-alpha - 2007-11-12
  This eleventh development snapshot fixes some build problems with
  the previous snapshot. It also includes a more secure-by-default exit
  policy for relays, fixes an enormous memory leak for exit relays, and
  fixes another bug where servers were falling out of the directory list.

  o Security fixes:
    - Exit policies now reject connections that are addressed to a
      relay's public (external) IP address too, unless
      ExitPolicyRejectPrivate is turned off. We do this because too
      many relays are running nearby to services that trust them based
      on network address. Bugfix on 0.1.2.x.

  o Major bugfixes:
    - Fix a memory leak on exit relays; we were leaking a cached_resolve_t
      on every successful resolve. Reported by Mike Perry; bugfix
      on 0.1.2.x.
    - On authorities, never downgrade to old router descriptors simply
      because they're listed in the consensus. This created a catch-22
      where we wouldn't list a new descriptor because there was an
      old one in the consensus, and we couldn't get the new one in the
      consensus because we wouldn't list it. Possible fix for bug 548.
      Also, this might cause bug 543 to appear on authorities; if so,
      we'll need a band-aid for that. Bugfix on 0.2.0.9-alpha.

  o Packaging fixes on 0.2.0.10-alpha:
    - We were including instructions about what to do with the
      src/config/fallback-consensus file, but we weren't actually
      including it in the tarball. Disable all of that for now.

  o Minor features:
    - Allow people to say PreferTunnelledDirConns rather than
      PreferTunneledDirConns, for those alternate-spellers out there.

  o Minor bugfixes:
    - Don't reevaluate all the information from our consensus document
      just because we've downloaded a v2 networkstatus that we intend
      to cache. Fixes bug 545; bugfix on 0.2.0.x.


Changes in version 0.2.0.10-alpha - 2007-11-10
  This tenth development snapshot adds a third v3 directory authority
  run by Mike Perry, adds most of Karsten Loesing's new hidden service
  descriptor format, fixes a bad crash bug and new bridge bugs introduced
  in 0.2.0.9-alpha, fixes many bugs with the v3 directory implementation,
  fixes some minor memory leaks in previous 0.2.0.x snapshots, and
  addresses many more minor issues.

  o New directory authorities:
    - Set up ides (run by Mike Perry) as the third v3 directory authority.

  o Major features:
    - Allow tunnelled directory connections to ask for an encrypted
      "begin_dir" connection or an anonymized "uses a full Tor circuit"
      connection independently. Now we can make anonymized begin_dir
      connections for (e.g.) more secure hidden service posting and
      fetching.
    - More progress on proposal 114: code from Karsten Loesing to
      implement new hidden service descriptor format.
    - Raise the default BandwidthRate/BandwidthBurst to 5MB/10MB, to
      accommodate the growing number of servers that use the default
      and are reaching it.
    - Directory authorities use a new formula for selecting which nodes
      to advertise as Guards: they must be in the top 7/8 in terms of
      how long we have known about them, and above the median of those
      nodes in terms of weighted fractional uptime.
    - Make "not enough dir info yet" warnings describe *why* Tor feels
      it doesn't have enough directory info yet.

  o Major bugfixes:
    - Stop servers from crashing if they set a Family option (or
      maybe in other situations too). Bugfix on 0.2.0.9-alpha; reported
      by Fabian Keil.
    - Make bridge users work again -- the move to v3 directories in
      0.2.0.9-alpha had introduced a number of bugs that made bridges
      no longer work for clients.
    - When the clock jumps forward a lot, do not allow the bandwidth
      buckets to become negative. Bugfix on 0.1.2.x; fixes bug 544.

  o Major bugfixes (v3 dir, bugfixes on 0.2.0.9-alpha):
    - When the consensus lists a router descriptor that we previously were
      mirroring, but that we considered non-canonical, reload the
      descriptor as canonical. This fixes bug 543 where Tor servers
      would start complaining after a few days that they don't have
      enough directory information to build a circuit.
    - Consider replacing the current consensus when certificates arrive
      that make the pending consensus valid. Previously, we were only
      considering replacement when the new certs _didn't_ help.
    - Fix an assert error on startup if we didn't already have the
      consensus and certs cached in our datadirectory: we were caching
      the consensus in consensus_waiting_for_certs but then free'ing it
      right after.
    - Avoid sending a request for "keys/fp" (for which we'll get a 400 Bad
      Request) if we need more v3 certs but we've already got pending
      requests for all of them.
    - Correctly back off from failing certificate downloads. Fixes
      bug 546.
    - Authorities don't vote on the Running flag if they have been running
      for less than 30 minutes themselves. Fixes bug 547, where a newly
      started authority would vote that everyone was down.

  o New requirements:
    - Drop support for OpenSSL version 0.9.6. Just about nobody was using
      it, it had no AES, and it hasn't seen any security patches since
      2004.

  o Minor features:
    - Clients now hold circuitless TLS connections open for 1.5 times
      MaxCircuitDirtiness (15 minutes), since it is likely that they'll
      rebuild a new circuit over them within that timeframe. Previously,
      they held them open only for KeepalivePeriod (5 minutes).
    - Use "If-Modified-Since" to avoid retrieving consensus
      networkstatuses that we already have.
    - When we have no consensus, check FallbackNetworkstatusFile (defaults
      to $PREFIX/share/tor/fallback-consensus) for a consensus. This way
      we start knowing some directory caches.
    - When we receive a consensus from the future, warn about skew.
    - Improve skew reporting: try to give the user a better log message
      about how skewed they are, and how much this matters.
    - When we have a certificate for an authority, believe that
      certificate's claims about the authority's IP address.
    - New --quiet command-line option to suppress the default console log.
      Good in combination with --hash-password.
    - Authorities send back an X-Descriptor-Not-New header in response to
      an accepted-but-discarded descriptor upload. Partially implements
      fix for bug 535.
    - Make the log message for "tls error. breaking." more useful.
    - Better log messages about certificate downloads, to attempt to
      track down the second incarnation of bug 546.

  o Minor features (bridges):
    - If bridge users set UpdateBridgesFromAuthority, but the digest
      they ask for is a 404 from the bridge authority, they now fall
      back to trying the bridge directly.
    - Bridges now use begin_dir to publish their server descriptor to
      the bridge authority, even when they haven't set TunnelDirConns.

  o Minor features (controller):
    - When reporting clock skew, and we know that the clock is _at least
      as skewed_ as some value, but we don't know the actual value,
      report the value as a "minimum skew."

  o Utilities:
    - Update linux-tor-prio.sh script to allow QoS based on the uid of
      the Tor process. Patch from Marco Bonetti with tweaks from Mike
      Perry.

  o Minor bugfixes:
    - Refuse to start if both ORPort and UseBridges are set. Bugfix
      on 0.2.0.x, suggested by Matt Edman.
    - Don't stop fetching descriptors when FetchUselessDescriptors is
      set, even if we stop asking for circuits. Bugfix on 0.1.2.x;
      reported by tup and ioerror.
    - Better log message on vote from unknown authority.
    - Don't log "Launching 0 request for 0 router" message.

  o Minor bugfixes (memory leaks):
    - Stop leaking memory every time we parse a v3 certificate. Bugfix
      on 0.2.0.1-alpha.
    - Stop leaking memory every time we load a v3 certificate. Bugfix
      on 0.2.0.1-alpha. Fixes bug 536.
    - Stop leaking a cached networkstatus on exit. Bugfix on
      0.2.0.3-alpha.
    - Stop leaking voter information every time we free a consensus.
      Bugfix on 0.2.0.3-alpha.
    - Stop leaking signed data every time we check a voter signature.
      Bugfix on 0.2.0.3-alpha.
    - Stop leaking a signature every time we fail to parse a consensus or
      a vote. Bugfix on 0.2.0.3-alpha.
    - Stop leaking v2_download_status_map on shutdown. Bugfix on
      0.2.0.9-alpha.
    - Stop leaking conn->nickname every time we make a connection to a
      Tor relay without knowing its expected identity digest (e.g. when
      using bridges). Bugfix on 0.2.0.3-alpha.

  - Minor bugfixes (portability):
    - Run correctly on platforms where rlim_t is larger than unsigned
      long, and/or where the real limit for number of open files is
      OPEN_FILES, not rlim_max from getrlimit(RLIMIT_NOFILES). In
      particular, these may be needed for OS X 10.5.


Changes in version 0.1.2.18 - 2007-10-28
  Tor 0.1.2.18 fixes many problems including crash bugs, problems with
  hidden service introduction that were causing huge delays, and a big
  bug that was causing some servers to disappear from the network status
  lists for a few hours each day.

  o Major bugfixes (crashes):
    - If a connection is shut down abruptly because of something that
      happened inside connection_flushed_some(), do not call
      connection_finished_flushing(). Should fix bug 451:
      "connection_stop_writing: Assertion conn->write_event failed"
      Bugfix on 0.1.2.7-alpha.
    - Fix possible segfaults in functions called from
      rend_process_relay_cell().

  o Major bugfixes (hidden services):
    - Hidden services were choosing introduction points uniquely by
      hexdigest, but when constructing the hidden service descriptor
      they merely wrote the (potentially ambiguous) nickname.
    - Clients now use the v2 intro format for hidden service
      connections: they specify their chosen rendezvous point by identity
      digest rather than by (potentially ambiguous) nickname. These
      changes could speed up hidden service connections dramatically.

  o Major bugfixes (other):
    - Stop publishing a new server descriptor just because we get a
      HUP signal. This led (in a roundabout way) to some servers getting
      dropped from the networkstatus lists for a few hours each day.
    - When looking for a circuit to cannibalize, consider family as well
      as identity. Fixes bug 438. Bugfix on 0.1.0.x (which introduced
      circuit cannibalization).
    - When a router wasn't listed in a new networkstatus, we were leaving
      the flags for that router alone -- meaning it remained Named,
      Running, etc -- even though absence from the networkstatus means
      that it shouldn't be considered to exist at all anymore. Now we
      clear all the flags for routers that fall out of the networkstatus
      consensus. Fixes bug 529.

  o Minor bugfixes:
    - Don't try to access (or alter) the state file when running
      --list-fingerprint or --verify-config or --hash-password. Resolves
      bug 499.
    - When generating information telling us how to extend to a given
      router, do not try to include the nickname if it is
      absent. Resolves bug 467.
    - Fix a user-triggerable segfault in expand_filename(). (There isn't
      a way to trigger this remotely.)
    - When sending a status event to the controller telling it that an
      OR address is reachable, set the port correctly. (Previously we
      were reporting the dir port.)
    - Fix a minor memory leak whenever a controller sends the PROTOCOLINFO
      command. Bugfix on 0.1.2.17.
    - When loading bandwidth history, do not believe any information in
      the future. Fixes bug 434.
    - When loading entry guard information, do not believe any information
      in the future.
    - When we have our clock set far in the future and generate an
      onion key, then re-set our clock to be correct, we should not stop
      the onion key from getting rotated.
    - On some platforms, accept() can return a broken address. Detect
      this more quietly, and deal accordingly. Fixes bug 483.
    - It's not actually an error to find a non-pending entry in the DNS
      cache when canceling a pending resolve. Don't log unless stuff
      is fishy. Resolves bug 463.
    - Don't reset trusted dir server list when we set a configuration
      option. Patch from Robert Hogan.
    - Don't try to create the datadir when running --verify-config or
      --hash-password. Resolves bug 540.


Changes in version 0.2.0.9-alpha - 2007-10-24
  This ninth development snapshot switches clients to the new v3 directory
  system; allows servers to be listed in the network status even when they
  have the same nickname as a registered server; and fixes many other
  bugs including a big one that was causing some servers to disappear
  from the network status lists for a few hours each day.

  o Major features (directory system):
    - Clients now download v3 consensus networkstatus documents instead
      of v2 networkstatus documents. Clients and caches now base their
      opinions about routers on these consensus documents. Clients only
      download router descriptors listed in the consensus.
    - Authorities now list servers who have the same nickname as
      a different named server, but list them with a new flag,
      "Unnamed". Now we can list servers that happen to pick the same
      nickname as a server that registered two years ago and then
      disappeared. Partially implements proposal 122.
    - If the consensus lists a router as "Unnamed", the name is assigned
      to a different router: do not identify the router by that name.
      Partially implements proposal 122.
    - Authorities can now come to a consensus on which method to use to
      compute the consensus. This gives us forward compatibility.

  o Major bugfixes:
    - Stop publishing a new server descriptor just because we HUP or
      when we find our DirPort to be reachable but won't actually publish
      it. New descriptors without any real changes are dropped by the
      authorities, and can screw up our "publish every 18 hours" schedule.
      Bugfix on 0.1.2.x.
    - When a router wasn't listed in a new networkstatus, we were leaving
      the flags for that router alone -- meaning it remained Named,
      Running, etc -- even though absence from the networkstatus means
      that it shouldn't be considered to exist at all anymore. Now we
      clear all the flags for routers that fall out of the networkstatus
      consensus. Fixes bug 529; bugfix on 0.1.2.x.
    - Fix awful behavior in DownloadExtraInfo option where we'd fetch
      extrainfo documents and then discard them immediately for not
      matching the latest router. Bugfix on 0.2.0.1-alpha.

  o Minor features (v3 directory protocol):
    - Allow tor-gencert to generate a new certificate without replacing
      the signing key.
    - Allow certificates to include an address.
    - When we change our directory-cache settings, reschedule all voting
      and download operations.
    - Reattempt certificate downloads immediately on failure, as long as
      we haven't failed a threshold number of times yet.
    - Delay retrying consensus downloads while we're downloading
      certificates to verify the one we just got. Also, count getting a
      consensus that we already have (or one that isn't valid) as a failure,
      and count failing to get the certificates after 20 minutes as a
      failure.
    - Build circuits and download descriptors even if our consensus is a
      little expired. (This feature will go away once authorities are
      more reliable.)

  o Minor features (router descriptor cache):
    - If we find a cached-routers file that's been sitting around for more
      than 28 days unmodified, then most likely it's a leftover from
      when we upgraded to 0.2.0.8-alpha. Remove it. It has no good
      routers anyway.
    - When we (as a cache) download a descriptor because it was listed
      in a consensus, remember when the consensus was supposed to expire,
      and don't expire the descriptor until then.

  o Minor features (performance):
    - Call routerlist_remove_old_routers() much less often. This should
      speed startup, especially on directory caches.
    - Don't try to launch new descriptor downloads quite so often when we
      already have enough directory information to build circuits.
    - Base64 decoding was actually showing up on our profile when parsing
      the initial descriptor file; switch to an in-process all-at-once
      implementation that's about 3.5x times faster than calling out to
      OpenSSL.

  o Minor features (compilation):
    - Detect non-ASCII platforms (if any still exist) and refuse to
      build there: some of our code assumes that 'A' is 65 and so on.

  o Minor bugfixes (v3 directory authorities, bugfixes on 0.2.0.x):
    - Make the "next period" votes into "current period" votes immediately
      after publishing the consensus; avoid a heisenbug that made them
      stick around indefinitely.
    - When we discard a vote as a duplicate, do not report this as
      an error.
    - Treat missing v3 keys or certificates as an error when running as a
      v3 directory authority.
    - When we're configured to be a v3 authority, but we're only listed
      as a non-v3 authority in our DirServer line for ourself, correct
      the listing.
    - If an authority doesn't have a qualified hostname, just put
      its address in the vote. This fixes the problem where we referred to
      "moria on moria:9031."
    - Distinguish between detached signatures for the wrong period, and
      detached signatures for a divergent vote.
    - Fix a small memory leak when computing a consensus.
    - When there's no concensus, we were forming a vote every 30
      minutes, but writing the "valid-after" line in our vote based
      on our configured V3AuthVotingInterval: so unless the intervals
      matched up, we immediately rejected our own vote because it didn't
      start at the voting interval that caused us to construct a vote.

  o Minor bugfixes (v3 directory protocol, bugfixes on 0.2.0.x):
    - Delete unverified-consensus when the real consensus is set.
    - Consider retrying a consensus networkstatus fetch immediately
      after one fails: don't wait 60 seconds to notice.
    - When fetching a consensus as a cache, wait until a newer consensus
      should exist before trying to replace the current one.
    - Use a more forgiving schedule for retrying failed consensus
      downloads than for other types.

  o Minor bugfixes (other directory issues):
    - Correct the implementation of "download votes by digest." Bugfix on
      0.2.0.8-alpha.
    - Authorities no longer send back "400 you're unreachable please fix
      it" errors to Tor servers that aren't online all the time. We're
      supposed to tolerate these servers now. Bugfix on 0.1.2.x.

  o Minor bugfixes (controller):
    - Don't reset trusted dir server list when we set a configuration
      option. Patch from Robert Hogan; bugfix on 0.1.2.x.
    - Respond to INT and TERM SIGNAL commands before we execute the
      signal, in case the signal shuts us down. We had a patch in
      0.1.2.1-alpha that tried to do this by queueing the response on
      the connection's buffer before shutting down, but that really
      isn't the same thing at all. Bug located by Matt Edman.

  o Minor bugfixes (misc):
    - Correctly check for bad options to the "PublishServerDescriptor"
      config option. Bugfix on 0.2.0.1-alpha; reported by Matt Edman.
    - Stop leaking memory on failing case of base32_decode, and make
      it accept upper-case letters. Bugfixes on 0.2.0.7-alpha.
    - Don't try to download extrainfo documents when we're trying to
      fetch enough directory info to build a circuit: having enough
      info should get priority. Bugfix on 0.2.0.x.
    - Don't complain that "your server has not managed to confirm that its
      ports are reachable" if we haven't been able to build any circuits
      yet. Bug found by spending four hours without a v3 consensus. Bugfix
      on 0.1.2.x.
    - Detect the reason for failing to mmap a descriptor file we just
      wrote, and give a more useful log message. Fixes bug 533. Bugfix
      on 0.1.2.x.

  o Code simplifications and refactoring:
    - Remove support for the old bw_accounting file: we've been storing
      bandwidth accounting information in the state file since
      0.1.2.5-alpha. This may result in bandwidth accounting errors
      if you try to upgrade from 0.1.1.x or earlier, or if you try to
      downgrade to 0.1.1.x or earlier.
    - New convenience code to locate a file within the DataDirectory.
    - Move non-authority functionality out of dirvote.c.
    - Refactor the arguments for router_pick_{directory_|trusteddir}server
      so that they all take the same named flags.

  o Utilities
    - Include the "tor-ctrl.sh" bash script by Stefan Behte to provide
      Unix users an easy way to script their Tor process (e.g. by
      adjusting bandwidth based on the time of the day).


Changes in version 0.2.0.8-alpha - 2007-10-12
  This eighth development snapshot fixes a crash bug that's been bothering
  us since February 2007, lets bridge authorities store a list of bridge
  descriptors they've seen, gets v3 directory voting closer to working,
  starts caching v3 directory consensus documents on directory mirrors,
  and fixes a variety of smaller issues including some minor memory leaks.

  o Major features (router descriptor cache):
    - Store routers in a file called cached-descriptors instead of in
      cached-routers. Initialize cached-descriptors from cached-routers
      if the old format is around. The new format allows us to store
      annotations along with descriptors.
    - Use annotations to record the time we received each descriptor, its
      source, and its purpose.
    - Disable the SETROUTERPURPOSE controller command: it is now
      obsolete.
    - Controllers should now specify cache=no or cache=yes when using
      the +POSTDESCRIPTOR command.
    - Bridge authorities now write bridge descriptors to disk, meaning
      we can export them to other programs and begin distributing them
      to blocked users.

  o Major features (directory authorities):
    - When a v3 authority is missing votes or signatures, it now tries
      to fetch them.
    - Directory authorities track weighted fractional uptime as well as
      weighted mean-time-between failures. WFU is suitable for deciding
      whether a node is "usually up", while MTBF is suitable for deciding
      whether a node is "likely to stay up." We need both, because
      "usually up" is a good requirement for guards, while "likely to
      stay up" is a good requirement for long-lived connections.

  o Major features (v3 directory system):
    - Caches now download v3 network status documents as needed,
      and download the descriptors listed in them.
    - All hosts now attempt to download and keep fresh v3 authority
      certificates, and re-attempt after failures.
    - More internal-consistency checks for vote parsing.

  o Major bugfixes (crashes):
    - If a connection is shut down abruptly because of something that
      happened inside connection_flushed_some(), do not call
      connection_finished_flushing(). Should fix bug 451. Bugfix on
      0.1.2.7-alpha.

  o Major bugfixes (performance):
    - Fix really bad O(n^2) performance when parsing a long list of
      routers: Instead of searching the entire list for an "extra-info "
      string which usually wasn't there, once for every routerinfo
      we read, just scan lines forward until we find one we like.
      Bugfix on 0.2.0.1.
    - When we add data to a write buffer in response to the data on that
      write buffer getting low because of a flush, do not consider the
      newly added data as a candidate for immediate flushing, but rather
      make it wait until the next round of writing. Otherwise, we flush
      and refill recursively, and a single greedy TLS connection can
      eat all of our bandwidth. Bugfix on 0.1.2.7-alpha.

  o Minor features (v3 authority system):
    - Add more ways for tools to download the votes that lead to the
      current consensus.
    - Send a 503 when low on bandwidth and a vote, consensus, or
      certificate is requested.
    - If-modified-since is now implemented properly for all kinds of
      certificate requests.

  o Minor bugfixes (network statuses):
    - Tweak the implementation of proposal 109 slightly: allow at most
      two Tor servers on the same IP address, except if it's the location
      of a directory authority, in which case allow five. Bugfix on
      0.2.0.3-alpha.

  o Minor bugfixes (controller):
    - When sending a status event to the controller telling it that an
      OR address is reachable, set the port correctly. (Previously we
      were reporting the dir port.) Bugfix on 0.1.2.x.

  o Minor bugfixes (v3 directory system):
    - Fix logic to look up a cert by its signing key digest. Bugfix on
      0.2.0.7-alpha.
    - Only change the reply to a vote to "OK" if it's not already
      set. This gets rid of annoying "400 OK" log messages, which may
      have been masking some deeper issue. Bugfix on 0.2.0.7-alpha.
    - When we get a valid consensus, recompute the voting schedule.
    - Base the valid-after time of a vote on the consensus voting
      schedule, not on our preferred schedule.
    - Make the return values and messages from signature uploads and
      downloads more sensible.
    - Fix a memory leak when serving votes and consensus documents, and
      another when serving certificates.

  o Minor bugfixes (performance):
    - Use a slightly simpler string hashing algorithm (copying Python's
      instead of Java's) and optimize our digest hashing algorithm to take
      advantage of 64-bit platforms and to remove some possibly-costly
      voodoo.
    - Fix a minor memory leak whenever we parse guards from our state
      file. Bugfix on 0.2.0.7-alpha.
    - Fix a minor memory leak whenever we write out a file. Bugfix on
      0.2.0.7-alpha.
    - Fix a minor memory leak whenever a controller sends the PROTOCOLINFO
      command. Bugfix on 0.2.0.5-alpha.

  o Minor bugfixes (portability):
    - On some platforms, accept() can return a broken address. Detect
      this more quietly, and deal accordingly. Fixes bug 483.
    - Stop calling tor_strlower() on uninitialized memory in some cases.
      Bugfix in 0.2.0.7-alpha.

  o Minor bugfixes (usability):
    - Treat some 403 responses from directory servers as INFO rather than
      WARN-severity events.
    - It's not actually an error to find a non-pending entry in the DNS
      cache when canceling a pending resolve. Don't log unless stuff is
      fishy. Resolves bug 463.

  o Minor bugfixes (anonymity):
    - Never report that we've used more bandwidth than we're willing to
      relay: it leaks how much non-relay traffic we're using. Resolves
      bug 516.
    - When looking for a circuit to cannibalize, consider family as well
      as identity. Fixes bug 438. Bugfix on 0.1.0.x (which introduced
      circuit cannibalization).

  o Code simplifications and refactoring:
    - Make a bunch of functions static. Remove some dead code.
    - Pull out about a third of the really big routerlist.c; put it in a
      new module, networkstatus.c.
    - Merge the extra fields in local_routerstatus_t back into
      routerstatus_t: we used to need one routerstatus_t for each
      authority's opinion, plus a local_routerstatus_t for the locally
      computed consensus opinion. To save space, we put the locally
      modified fields into local_routerstatus_t, and only the common
      stuff into routerstatus_t. But once v3 directories are in use,
      clients and caches will no longer need to hold authority opinions;
      thus, the rationale for keeping the types separate is now gone.
    - Make the code used to reschedule and reattempt downloads more
      uniform.
    - Turn all 'Are we a directory server/mirror?' logic into a call to
      dirserver_mode().
    - Remove the code to generate the oldest (v1) directory format.
      The code has been disabled since 0.2.0.5-alpha.


Changes in version 0.2.0.7-alpha - 2007-09-21
  This seventh development snapshot makes bridges work again, makes bridge
  authorities work for the first time, fixes two huge performance flaws
  in hidden services, and fixes a variety of minor issues.

  o New directory authorities:
    - Set up moria1 and tor26 as the first v3 directory authorities. See
      doc/spec/dir-spec.txt for details on the new directory design.

  o Major bugfixes (crashes):
    - Fix possible segfaults in functions called from
      rend_process_relay_cell(). Bugfix on 0.1.2.x.

  o Major bugfixes (bridges):
    - Fix a bug that made servers send a "404 Not found" in response to
      attempts to fetch their server descriptor. This caused Tor servers
      to take many minutes to establish reachability for their DirPort,
      and it totally crippled bridges. Bugfix on 0.2.0.5-alpha.
    - Make "UpdateBridgesFromAuthority" torrc option work: when bridge
      users configure that and specify a bridge with an identity
      fingerprint, now they will lookup the bridge descriptor at the
      default bridge authority via a one-hop tunnel, but once circuits
      are established they will switch to a three-hop tunnel for later
      connections to the bridge authority. Bugfix in 0.2.0.3-alpha.

  o Major bugfixes (hidden services):
    - Hidden services were choosing introduction points uniquely by
      hexdigest, but when constructing the hidden service descriptor
      they merely wrote the (potentially ambiguous) nickname.
    - Clients now use the v2 intro format for hidden service
      connections: they specify their chosen rendezvous point by identity
      digest rather than by (potentially ambiguous) nickname. Both
      are bugfixes on 0.1.2.x, and they could speed up hidden service
      connections dramatically. Thanks to Karsten Loesing.

  o Minor features (security):
    - As a client, do not believe any server that tells us that an
      address maps to an internal address space.
    - Make it possible to enable HashedControlPassword and
      CookieAuthentication at the same time.

  o Minor features (guard nodes):
    - Tag every guard node in our state file with the version that
      we believe added it, or with our own version if we add it. This way,
      if a user temporarily runs an old version of Tor and then switches
      back to a new one, she doesn't automatically lose her guards.

  o Minor features (speed):
    - When implementing AES counter mode, update only the portions of the
      counter buffer that need to change, and don't keep separate
      network-order and host-order counters when they are the same (i.e.,
      on big-endian hosts.)

  o Minor features (controller):
    - Accept LF instead of CRLF on controller, since some software has a
      hard time generating real Internet newlines.
    - Add GETINFO values for the server status events
      "REACHABILITY_SUCCEEDED" and "GOOD_SERVER_DESCRIPTOR". Patch from
      Robert Hogan.

  o Removed features:
     - Routers no longer include bandwidth-history lines in their
       descriptors; this information is already available in extra-info
       documents, and including it in router descriptors took up 60%
       (!) of compressed router descriptor downloads. Completes
       implementation of proposal 104.
     - Remove the contrib scripts ExerciseServer.py, PathDemo.py,
       and TorControl.py, as they use the old v0 controller protocol,
       and are obsoleted by TorFlow anyway.
     - Drop support for v1 rendezvous descriptors, since we never used
       them anyway, and the code has probably rotted by now. Based on
       patch from Karsten Loesing.
     - On OSX, stop warning the user that kqueue support in libevent is
      "experimental", since it seems to have worked fine for ages.

  o Minor bugfixes:
    - When generating information telling us how to extend to a given
      router, do not try to include the nickname if it is absent. Fixes
      bug 467. Bugfix on 0.2.0.3-alpha.
    - Fix a user-triggerable (but not remotely-triggerable) segfault
      in expand_filename(). Bugfix on 0.1.2.x.
    - Fix a memory leak when freeing incomplete requests from DNSPort.
      Found by Niels Provos with valgrind. Bugfix on 0.2.0.1-alpha.
    - Don't try to access (or alter) the state file when running
      --list-fingerprint or --verify-config or --hash-password. (Resolves
      bug 499.) Bugfix on 0.1.2.x.
    - Servers used to decline to publish their DirPort if their
      BandwidthRate, RelayBandwidthRate, or MaxAdvertisedBandwidth
      were below a threshold. Now they only look at BandwidthRate and
      RelayBandwidthRate. Bugfix on 0.1.2.x.
    - Remove an optimization in the AES counter-mode code that assumed
      that the counter never exceeded 2^68. When the counter can be set
      arbitrarily as an IV (as it is by Karsten's new hidden services
      code), this assumption no longer holds. Bugfix on 0.1.2.x.
    - Resume listing "AUTHORITY" flag for authorities in network status.
      Bugfix on 0.2.0.3-alpha; reported by Alex de Joode.

  o Code simplifications and refactoring:
    - Revamp file-writing logic so we don't need to have the entire
      contents of a file in memory at once before we write to disk. Tor,
      meet stdio.
    - Turn "descriptor store" into a full-fledged type.
    - Move all NT services code into a separate source file.
    - Unify all code that computes medians, percentile elements, etc.
    - Get rid of a needless malloc when parsing address policies.


Changes in version 0.1.2.17 - 2007-08-30
  Tor 0.1.2.17 features a new Vidalia version in the Windows and OS
  X bundles. Vidalia 0.0.14 makes authentication required for the
  ControlPort in the default configuration, which addresses important
  security risks. Everybody who uses Vidalia (or another controller)
  should upgrade.

  In addition, this Tor update fixes major load balancing problems with
  path selection, which should speed things up a lot once many people
  have upgraded.

  o Major bugfixes (security):
    - We removed support for the old (v0) control protocol. It has been
      deprecated since Tor 0.1.1.1-alpha, and keeping it secure has
      become more of a headache than it's worth.

  o Major bugfixes (load balancing):
    - When choosing nodes for non-guard positions, weight guards
      proportionally less, since they already have enough load. Patch
      from Mike Perry.
    - Raise the "max believable bandwidth" from 1.5MB/s to 10MB/s. This
      will allow fast Tor servers to get more attention.
    - When we're upgrading from an old Tor version, forget our current
      guards and pick new ones according to the new weightings. These
      three load balancing patches could raise effective network capacity
      by a factor of four. Thanks to Mike Perry for measurements.

  o Major bugfixes (stream expiration):
    - Expire not-yet-successful application streams in all cases if
      they've been around longer than SocksTimeout. Right now there are
      some cases where the stream will live forever, demanding a new
      circuit every 15 seconds. Fixes bug 454; reported by lodger.

  o Minor features (controller):
    - Add a PROTOCOLINFO controller command. Like AUTHENTICATE, it
      is valid before any authentication has been received. It tells
      a controller what kind of authentication is expected, and what
      protocol is spoken. Implements proposal 119.

  o Minor bugfixes (performance):
    - Save on most routerlist_assert_ok() calls in routerlist.c, thus
      greatly speeding up loading cached-routers from disk on startup.
    - Disable sentinel-based debugging for buffer code: we squashed all
      the bugs that this was supposed to detect a long time ago, and now
      its only effect is to change our buffer sizes from nice powers of
      two (which platform mallocs tend to like) to values slightly over
      powers of two (which make some platform mallocs sad).

  o Minor bugfixes (misc):
    - If exit bandwidth ever exceeds one third of total bandwidth, then
      use the correct formula to weight exit nodes when choosing paths.
      Based on patch from Mike Perry.
    - Choose perfectly fairly among routers when choosing by bandwidth and
      weighting by fraction of bandwidth provided by exits. Previously, we
      would choose with only approximate fairness, and correct ourselves
      if we ran off the end of the list.
    - If we require CookieAuthentication but we fail to write the
      cookie file, we would warn but not exit, and end up in a state
      where no controller could authenticate. Now we exit.
    - If we require CookieAuthentication, stop generating a new cookie
      every time we change any piece of our config.
    - Refuse to start with certain directory authority keys, and
      encourage people using them to stop.
    - Terminate multi-line control events properly. Original patch
      from tup.
    - Fix a minor memory leak when we fail to find enough suitable
      servers to choose a circuit.
    - Stop leaking part of the descriptor when we run into a particularly
      unparseable piece of it.


Changes in version 0.2.0.6-alpha - 2007-08-26
  This sixth development snapshot features a new Vidalia version in the
  Windows and OS X bundles. Vidalia 0.0.14 makes authentication required for
  the ControlPort in the default configuration, which addresses important
  security risks.

  In addition, this snapshot fixes major load balancing problems
  with path selection, which should speed things up a lot once many
  people have upgraded. The directory authorities also use a new
  mean-time-between-failure approach to tracking which servers are stable,
  rather than just looking at the most recent uptime.

  o New directory authorities:
    - Set up Tonga as the default bridge directory authority.

  o Major features:
    - Directory authorities now track servers by weighted
      mean-times-between-failures. When we have 4 or more days of data,
      use measured MTBF rather than declared uptime to decide whether
      to call a router Stable. Implements proposal 108.

  o Major bugfixes (load balancing):
    - When choosing nodes for non-guard positions, weight guards
      proportionally less, since they already have enough load. Patch
      from Mike Perry.
    - Raise the "max believable bandwidth" from 1.5MB/s to 10MB/s. This
      will allow fast Tor servers to get more attention.
    - When we're upgrading from an old Tor version, forget our current
      guards and pick new ones according to the new weightings. These
      three load balancing patches could raise effective network capacity
      by a factor of four. Thanks to Mike Perry for measurements.

  o Major bugfixes (descriptor parsing):
    - Handle unexpected whitespace better in malformed descriptors. Bug
      found using Benedikt Boss's new Tor fuzzer! Bugfix on 0.2.0.x.

  o Minor features:
    - There is now an ugly, temporary "desc/all-recent-extrainfo-hack"
      GETINFO for Torstat to use until it can switch to using extrainfos.
    - Optionally (if built with -DEXPORTMALLINFO) export the output
      of mallinfo via http, as tor/mallinfo.txt. Only accessible
      from localhost.

  o Minor bugfixes:
    - Do not intermix bridge routers with controller-added
      routers. (Bugfix on 0.2.0.x)
    - Do not fail with an assert when accept() returns an unexpected
      address family. Addresses but does not wholly fix bug 483. (Bugfix
      on 0.2.0.x)
    - Let directory authorities startup even when they can't generate
      a descriptor immediately, e.g. because they don't know their
      address.
    - Stop putting the authentication cookie in a file called "0"
      in your working directory if you don't specify anything for the
      new CookieAuthFile option. Reported by Matt Edman.
    - Make it possible to read the PROTOCOLINFO response in a way that
      conforms to our control-spec. Reported by Matt Edman.
    - Fix a minor memory leak when we fail to find enough suitable
      servers to choose a circuit. Bugfix on 0.1.2.x.
    - Stop leaking part of the descriptor when we run into a particularly
      unparseable piece of it. Bugfix on 0.1.2.x.
    - Unmap the extrainfo cache file on exit.


Changes in version 0.2.0.5-alpha - 2007-08-19
  This fifth development snapshot fixes compilation on Windows again;
  fixes an obnoxious client-side bug that slowed things down and put
  extra load on the network; gets us closer to using the v3 directory
  voting scheme; makes it easier for Tor controllers to use cookie-based
  authentication; and fixes a variety of other bugs.

  o Removed features:
    - Version 1 directories are no longer generated in full. Instead,
      authorities generate and serve "stub" v1 directories that list
      no servers. This will stop Tor versions 0.1.0.x and earlier from
      working, but (for security reasons) nobody should be running those
      versions anyway.

  o Major bugfixes (compilation, 0.2.0.x):
    - Try to fix Win32 compilation again: improve checking for IPv6 types.
    - Try to fix MSVC compilation: build correctly on platforms that do
      not define s6_addr16 or s6_addr32.
    - Fix compile on platforms without getaddrinfo: bug found by Li-Hui
      Zhou.

  o Major bugfixes (stream expiration):
    - Expire not-yet-successful application streams in all cases if
      they've been around longer than SocksTimeout. Right now there are
      some cases where the stream will live forever, demanding a new
      circuit every 15 seconds. Bugfix on 0.1.2.7-alpha; fixes bug 454;
      reported by lodger.

  o Minor features (directory servers):
    - When somebody requests a list of statuses or servers, and we have
      none of those, return a 404 rather than an empty 200.

  o Minor features (directory voting):
    - Store v3 consensus status consensuses on disk, and reload them
      on startup.

  o Minor features (security):
    - Warn about unsafe ControlPort configurations.
    - Refuse to start with certain directory authority keys, and
      encourage people using them to stop.

  o Minor features (controller):
    - Add a PROTOCOLINFO controller command. Like AUTHENTICATE, it
      is valid before any authentication has been received. It tells
      a controller what kind of authentication is expected, and what
      protocol is spoken. Implements proposal 119.
    - New config option CookieAuthFile to choose a new location for the
      cookie authentication file, and config option
      CookieAuthFileGroupReadable to make it group-readable.

  o Minor features (unit testing):
    - Add command-line arguments to unit-test executable so that we can
      invoke any chosen test from the command line rather than having
      to run the whole test suite at once; and so that we can turn on
      logging for the unit tests.

  o Minor bugfixes (on 0.1.2.x):
    - If we require CookieAuthentication but we fail to write the
      cookie file, we would warn but not exit, and end up in a state
      where no controller could authenticate. Now we exit.
    - If we require CookieAuthentication, stop generating a new cookie
      every time we change any piece of our config.
    - When loading bandwidth history, do not believe any information in
      the future. Fixes bug 434.
    - When loading entry guard information, do not believe any information
      in the future.
    - When we have our clock set far in the future and generate an
      onion key, then re-set our clock to be correct, we should not stop
      the onion key from getting rotated.
    - Clean up torrc sample config file.
    - Do not automatically run configure from autogen.sh. This
      non-standard behavior tended to annoy people who have built other
      programs.

  o Minor bugfixes (on 0.2.0.x):
    - Fix a bug with AutomapHostsOnResolve that would always cause
      the second request to fail. Bug reported by Kate. Bugfix on
      0.2.0.3-alpha.
    - Fix a bug in ADDRMAP controller replies that would sometimes
      try to print a NULL. Patch from tup.
    - Read v3 directory authority keys from the right location.
    - Numerous bugfixes to directory voting code.


Changes in version 0.1.2.16 - 2007-08-01
  Tor 0.1.2.16 fixes a critical security vulnerability that allows a
  remote attacker in certain situations to rewrite the user's torrc
  configuration file. This can completely compromise anonymity of users
  in most configurations, including those running the Vidalia bundles,
  TorK, etc. Or worse.

  o Major security fixes:
    - Close immediately after missing authentication on control port;
      do not allow multiple authentication attempts.


Changes in version 0.2.0.4-alpha - 2007-08-01
  This fourth development snapshot fixes a critical security vulnerability
  for most users, specifically those running Vidalia, TorK, etc. Everybody
  should upgrade to either 0.1.2.16 or 0.2.0.4-alpha.

  o Major security fixes:
    - Close immediately after missing authentication on control port;
      do not allow multiple authentication attempts.

  o Major bugfixes (compilation):
    - Fix win32 compilation: apparently IN_ADDR and IN6_ADDR are already
      defined there.

  o Minor features (performance):
    - Be even more aggressive about releasing RAM from small
      empty buffers. Thanks to our free-list code, this shouldn't be too
      performance-intensive.
    - Disable sentinel-based debugging for buffer code: we squashed all
      the bugs that this was supposed to detect a long time ago, and
      now its only effect is to change our buffer sizes from nice
      powers of two (which platform mallocs tend to like) to values
      slightly over powers of two (which make some platform mallocs sad).
    - Log malloc statistics from mallinfo() on platforms where it
      exists.


Changes in version 0.2.0.3-alpha - 2007-07-29
  This third development snapshot introduces new experimental
  blocking-resistance features and a preliminary version of the v3
  directory voting design, and includes many other smaller features
  and bugfixes.

  o Major features:
    - The first pieces of our "bridge" design for blocking-resistance
      are implemented. People can run bridge directory authorities;
      people can run bridges; and people can configure their Tor clients
      with a set of bridges to use as the first hop into the Tor network.
      See http://archives.seul.org/or/talk/Jul-2007/msg00249.html for
      details.
    - Create listener connections before we setuid to the configured
      User and Group. Now non-Windows users can choose port values
      under 1024, start Tor as root, and have Tor bind those ports
      before it changes to another UID. (Windows users could already
      pick these ports.)
    - Added a new ConstrainedSockets config option to set SO_SNDBUF and
      SO_RCVBUF on TCP sockets. Hopefully useful for Tor servers running
      on "vserver" accounts. (Patch from coderman.)
    - Be even more aggressive about separating local traffic from relayed
      traffic when RelayBandwidthRate is set. (Refines proposal 111.)

  o Major features (experimental):
    - First cut of code for "v3 dir voting": directory authorities will
      vote on a common network status document rather than each publishing
      their own opinion. This code needs more testing and more corner-case
      handling before it's ready for use.

  o Security fixes:
    - Directory authorities now call routers Fast if their bandwidth is
      at least 100KB/s, and consider their bandwidth adequate to be a
      Guard if it is at least 250KB/s, no matter the medians. This fix
      complements proposal 107. [Bugfix on 0.1.2.x]
    - Directory authorities now never mark more than 3 servers per IP as
      Valid and Running. (Implements proposal 109, by Kevin Bauer and
      Damon McCoy.)
    - Minor change to organizationName and commonName generation
      procedures in TLS certificates during Tor handshakes, to invalidate
      some earlier censorware approaches. This is not a long-term
      solution, but applying it will give us a bit of time to look into
      the epidemiology of countermeasures as they spread.

  o Major bugfixes (directory):
    - Rewrite directory tokenization code to never run off the end of
      a string. Fixes bug 455. Patch from croup. [Bugfix on 0.1.2.x]

  o Minor features (controller):
    - Add a SOURCE_ADDR field to STREAM NEW events so that controllers can
      match requests to applications. (Patch from Robert Hogan.)
    - Report address and port correctly on connections to DNSPort. (Patch
      from Robert Hogan.)
    - Add a RESOLVE command to launch hostname lookups. (Original patch
      from Robert Hogan.)
    - Add GETINFO status/enough-dir-info to let controllers tell whether
      Tor has downloaded sufficient directory information. (Patch
      from Tup.)
    - You can now use the ControlSocket option to tell Tor to listen for
      controller connections on Unix domain sockets on systems that
      support them. (Patch from Peter Palfrader.)
    - STREAM NEW events are generated for DNSPort requests and for
      tunneled directory connections. (Patch from Robert Hogan.)
    - New "GETINFO address-mappings/*" command to get address mappings
      with expiry information. "addr-mappings/*" is now deprecated.
      (Patch from Tup.)

  o Minor features (misc):
    - Merge in some (as-yet-unused) IPv6 address manipulation code. (Patch
      from croup.)
    - The tor-gencert tool for v3 directory authorities now creates all
      files as readable to the file creator only, and write-protects
      the authority identity key.
    - When dumping memory usage, list bytes used in buffer memory
      free-lists.
    - When running with dmalloc, dump more stats on hup and on exit.
    - Directory authorities now fail quickly and (relatively) harmlessly
      if they generate a network status document that is somehow
      malformed.

  o Traffic load balancing improvements:
    - If exit bandwidth ever exceeds one third of total bandwidth, then
      use the correct formula to weight exit nodes when choosing paths.
      (Based on patch from Mike Perry.)
    - Choose perfectly fairly among routers when choosing by bandwidth and
      weighting by fraction of bandwidth provided by exits. Previously, we
      would choose with only approximate fairness, and correct ourselves
      if we ran off the end of the list. [Bugfix on 0.1.2.x]

  o Performance improvements:
    - Be more aggressive with freeing buffer RAM or putting it on the
      memory free lists.
    - Use Critical Sections rather than Mutexes for synchronizing threads
      on win32; Mutexes are heavier-weight, and designed for synchronizing
      between processes.

  o Deprecated and removed features:
    - RedirectExits is now deprecated.
    - Stop allowing address masks that do not correspond to bit prefixes.
      We have warned about these for a really long time; now it's time
      to reject them. (Patch from croup.)

  o Minor bugfixes (directory):
    - Fix another crash bug related to extra-info caching. (Bug found by
      Peter Palfrader.) [Bugfix on 0.2.0.2-alpha]
    - Directories no longer return a "304 not modified" when they don't
      have the networkstatus the client asked for. Also fix a memory
      leak when returning 304 not modified. [Bugfixes on 0.2.0.2-alpha]
    - We had accidentally labelled 0.1.2.x directory servers as not
      suitable for begin_dir requests, and had labelled no directory
      servers as suitable for uploading extra-info documents. [Bugfix
      on 0.2.0.1-alpha]

  o Minor bugfixes (dns):
    - Fix a crash when DNSPort is set more than once. (Patch from Robert
      Hogan.) [Bugfix on 0.2.0.2-alpha]
    - Add DNSPort connections to the global connection list, so that we
      can time them out correctly. (Bug found by Robert Hogan.) [Bugfix
      on 0.2.0.2-alpha]
    - Fix a dangling reference that could lead to a crash when DNSPort is
      changed or closed (Patch from Robert Hogan.) [Bugfix on
      0.2.0.2-alpha]

  o Minor bugfixes (controller):
    - Provide DNS expiry times in GMT, not in local time. For backward
      compatibility, ADDRMAP events only provide GMT expiry in an extended
      field. "GETINFO address-mappings" always does the right thing.
    - Use CRLF line endings properly in NS events.
    - Terminate multi-line control events properly. (Original patch
      from tup.) [Bugfix on 0.1.2.x-alpha]
    - Do not include spaces in SOURCE_ADDR fields in STREAM
      events. Resolves bug 472. [Bugfix on 0.2.0.x-alpha]


Changes in version 0.1.2.15 - 2007-07-17
  Tor 0.1.2.15 fixes several crash bugs, fixes some anonymity-related
  problems, fixes compilation on BSD, and fixes a variety of other
  bugs. Everybody should upgrade.

  o Major bugfixes (compilation):
    - Fix compile on FreeBSD/NetBSD/OpenBSD. Oops.

  o Major bugfixes (crashes):
    - Try even harder not to dereference the first character after
      an mmap(). Reported by lodger.
    - Fix a crash bug in directory authorities when we re-number the
      routerlist while inserting a new router.
    - When the cached-routers file is an even multiple of the page size,
      don't run off the end and crash. (Fixes bug 455; based on idea
      from croup.)
    - Fix eventdns.c behavior on Solaris: It is critical to include
      orconfig.h _before_ sys/types.h, so that we can get the expected
      definition of _FILE_OFFSET_BITS.

  o Major bugfixes (security):
    - Fix a possible buffer overrun when using BSD natd support. Bug
      found by croup.
    - When sending destroy cells from a circuit's origin, don't include
      the reason for tearing down the circuit. The spec says we didn't,
      and now we actually don't. Reported by lodger.
    - Keep streamids from different exits on a circuit separate. This
      bug may have allowed other routers on a given circuit to inject
      cells into streams. Reported by lodger; fixes bug 446.
    - If there's a never-before-connected-to guard node in our list,
      never choose any guards past it. This way we don't expand our
      guard list unless we need to.

  o Minor bugfixes (guard nodes):
    - Weight guard selection by bandwidth, so that low-bandwidth nodes
      don't get overused as guards.

  o Minor bugfixes (directory):
    - Correctly count the number of authorities that recommend each
      version. Previously, we were under-counting by 1.
    - Fix a potential crash bug when we load many server descriptors at
      once and some of them make others of them obsolete. Fixes bug 458.

  o Minor bugfixes (hidden services):
    - Stop tearing down the whole circuit when the user asks for a
      connection to a port that the hidden service didn't configure.
      Resolves bug 444.

  o Minor bugfixes (misc):
    - On Windows, we were preventing other processes from reading
      cached-routers while Tor was running. Reported by janbar.
    - Fix a possible (but very unlikely) bug in picking routers by
      bandwidth. Add a log message to confirm that it is in fact
      unlikely. Patch from lodger.
    - Backport a couple of memory leak fixes.
    - Backport miscellaneous cosmetic bugfixes.


Changes in version 0.2.0.2-alpha - 2007-06-02
  o Major bugfixes on 0.2.0.1-alpha:
    - Fix an assertion failure related to servers without extra-info digests.
      Resolves bugs 441 and 442.

  o Minor features (directory):
    - Support "If-Modified-Since" when answering HTTP requests for
      directories, running-routers documents, and network-status documents.
      (There's no need to support it for router descriptors, since those
      are downloaded by descriptor digest.)

  o Minor build issues:
    - Clear up some MIPSPro compiler warnings.
    - When building from a tarball on a machine that happens to have SVK
      installed, report the micro-revision as whatever version existed
      in the tarball, not as "x".


Changes in version 0.2.0.1-alpha - 2007-06-01
  This early development snapshot provides new features for people running
  Tor as both a client and a server (check out the new RelayBandwidth
  config options); lets Tor run as a DNS proxy; and generally moves us
  forward on a lot of fronts.

  o Major features, server usability:
    - New config options RelayBandwidthRate and RelayBandwidthBurst:
      a separate set of token buckets for relayed traffic. Right now
      relayed traffic is defined as answers to directory requests, and
      OR connections that don't have any local circuits on them.

  o Major features, client usability:
    - A client-side DNS proxy feature to replace the need for
      dns-proxy-tor: Just set "DNSPort 9999", and Tor will now listen
      for DNS requests on port 9999, use the Tor network to resolve them
      anonymously, and send the reply back like a regular DNS server.
      The code still only implements a subset of DNS.
    - Make PreferTunneledDirConns and TunnelDirConns work even when
      we have no cached directory info. This means Tor clients can now
      do all of their connections protected by TLS.

  o Major features, performance and efficiency:
    - Directory authorities accept and serve "extra info" documents for
      routers. These documents contain fields from router descriptors
      that aren't usually needed, and that use a lot of excess
      bandwidth. Once these fields are removed from router descriptors,
      the bandwidth savings should be about 60%. [Partially implements
      proposal 104.]
    - Servers upload extra-info documents to any authority that accepts
      them. Authorities (and caches that have been configured to download
      extra-info documents) download them as needed. [Partially implements
      proposal 104.]
    - Change the way that Tor buffers data that it is waiting to write.
      Instead of queueing data cells in an enormous ring buffer for each
      client->OR or OR->OR connection, we now queue cells on a separate
      queue for each circuit. This lets us use less slack memory, and
      will eventually let us be smarter about prioritizing different kinds
      of traffic.
    - Use memory pools to allocate cells with better speed and memory
      efficiency, especially on platforms where malloc() is inefficient.
    - Stop reading on edge connections when their corresponding circuit
      buffers are full; start again as the circuits empty out.

  o Major features, other:
    - Add an HSAuthorityRecordStats option that hidden service authorities
      can use to track statistics of overall hidden service usage without
      logging information that would be very useful to an attacker.
    - Start work implementing multi-level keys for directory authorities:
      Add a standalone tool to generate key certificates. (Proposal 103.)

  o Security fixes:
    - Directory authorities now call routers Stable if they have an
      uptime of at least 30 days, even if that's not the median uptime
      in the network. Implements proposal 107, suggested by Kevin Bauer
      and Damon McCoy.

  o Minor fixes (resource management):
    - Count the number of open sockets separately from the number
      of active connection_t objects. This will let us avoid underusing
      our allocated connection limit.
    - We no longer use socket pairs to link an edge connection to an
      anonymous directory connection or a DirPort test connection.
      Instead, we track the link internally and transfer the data
      in-process. This saves two sockets per "linked" connection (at the
      client and at the server), and avoids the nasty Windows socketpair()
      workaround.
    - Keep unused 4k and 16k buffers on free lists, rather than wasting 8k
      for every single inactive connection_t. Free items from the
      4k/16k-buffer free lists when they haven't been used for a while.

  o Minor features (build):
    - Make autoconf search for libevent, openssl, and zlib consistently.
    - Update deprecated macros in configure.in.
    - When warning about missing headers, tell the user to let us
      know if the compile succeeds anyway, so we can downgrade the
      warning.
    - Include the current subversion revision as part of the version
      string: either fetch it directly if we're in an SVN checkout, do
      some magic to guess it if we're in an SVK checkout, or use
      the last-detected version if we're building from a .tar.gz.
      Use this version consistently in log messages.

  o Minor features (logging):
    - Always prepend "Bug: " to any log message about a bug.
    - Put a platform string (e.g. "Linux i686") in the startup log
      message, so when people paste just their logs, we know if it's
      OpenBSD or Windows or what.
    - When logging memory usage, break down memory used in buffers by
      buffer type.

  o Minor features (directory system):
    - New config option V2AuthoritativeDirectory that all directory
      authorities should set. This will let future authorities choose
      not to serve V2 directory information.
    - Directory authorities allow multiple router descriptors and/or extra
      info documents to be uploaded in a single go. This will make
      implementing proposal 104 simpler.

  o Minor features (controller):
    - Add a new config option __DisablePredictedCircuits designed for
      use by the controller, when we don't want Tor to build any circuits
      preemptively.
    - Let the controller specify HOP=%d as an argument to ATTACHSTREAM,
      so we can exit from the middle of the circuit.
    - Implement "getinfo status/circuit-established".
    - Implement "getinfo status/version/..." so a controller can tell
      whether the current version is recommended, and whether any versions
      are good, and how many authorities agree. (Patch from shibz.)

  o Minor features (hidden services):
    - Allow multiple HiddenServicePort directives with the same virtual
      port; when they occur, the user is sent round-robin to one
      of the target ports chosen at random. Partially fixes bug 393 by
      adding limited ad-hoc round-robining.

  o Minor features (other):
    - More unit tests.
    - Add a new AutomapHostsOnResolve option: when it is enabled, any
      resolve request for hosts matching a given pattern causes Tor to
      generate an internal virtual address mapping for that host. This
      allows DNSPort to work sensibly with hidden service users. By
      default, .exit and .onion addresses are remapped; the list of
      patterns can be reconfigured with AutomapHostsSuffixes.
    - Add an "-F" option to tor-resolve to force a resolve for a .onion
      address. Thanks to the AutomapHostsOnResolve option, this is no
      longer a completely silly thing to do.
    - If Tor is invoked from something that isn't a shell (e.g. Vidalia),
      now we expand "-f ~/.tor/torrc" correctly. Suggested by Matt Edman.
    - Treat "2gb" when given in torrc for a bandwidth as meaning 2gb,
      minus 1 byte: the actual maximum declared bandwidth.

  o Removed features:
    - Removed support for the old binary "version 0" controller protocol.
      This has been deprecated since 0.1.1, and warnings have been issued
      since 0.1.2. When we encounter a v0 control message, we now send
      back an error and close the connection.
    - Remove the old "dns worker" server DNS code: it hasn't been default
      since 0.1.2.2-alpha, and all the servers seem to be using the new
      eventdns code.

  o Minor bugfixes (portability):
    - Even though Windows is equally happy with / and \ as path separators,
      try to use \ consistently on Windows and / consistently on Unix: it
      makes the log messages nicer.
    - Correctly report platform name on Windows 95 OSR2 and Windows 98 SE.
    - Read resolv.conf files correctly on platforms where read() returns
      partial results on small file reads.

  o Minor bugfixes (directory):
    - Correctly enforce that elements of directory objects do not appear
      more often than they are allowed to appear.
    - When we are reporting the DirServer line we just parsed, we were
      logging the second stanza of the key fingerprint, not the first.

  o Minor bugfixes (logging):
    - When we hit an EOF on a log (probably because we're shutting down),
      don't try to remove the log from the list: just mark it as
      unusable. (Bulletproofs against bug 222.)

  o Minor bugfixes (other):
    - In the exitlist script, only consider the most recently published
      server descriptor for each server. Also, when the user requests
      a list of servers that _reject_ connections to a given address,
      explicitly exclude the IPs that also have servers that accept
      connections to that address. (Resolves bug 405.)
    - Stop allowing hibernating servers to be "stable" or "fast".
    - On Windows, we were preventing other processes from reading
      cached-routers while Tor was running. (Reported by janbar)
    - Make the NodeFamilies config option work. (Reported by
      lodger -- it has never actually worked, even though we added it
      in Oct 2004.)
    - Check return values from pthread_mutex functions.
    - Don't save non-general-purpose router descriptors to the disk cache,
      because we have no way of remembering what their purpose was when
      we restart.
    - Add even more asserts to hunt down bug 417.
    - Build without verbose warnings even on (not-yet-released) gcc 4.2.
    - Fix a possible (but very unlikely) bug in picking routers by bandwidth.
      Add a log message to confirm that it is in fact unlikely.

  o Minor bugfixes (controller):
    - Make 'getinfo fingerprint' return a 551 error if we're not a
      server, so we match what the control spec claims we do. Reported
      by daejees.
    - Fix a typo in an error message when extendcircuit fails that
      caused us to not follow the \r\n-based delimiter protocol. Reported
      by daejees.

  o Code simplifications and refactoring:
    - Stop passing around circuit_t and crypt_path_t pointers that are
      implicit in other procedure arguments.
    - Drop the old code to choke directory connections when the
      corresponding OR connections got full: thanks to the cell queue
      feature, OR conns don't get full any more.
    - Make dns_resolve() handle attaching connections to circuits
      properly, so the caller doesn't have to.
    - Rename wants_to_read and wants_to_write to read/write_blocked_on_bw.
    - Keep the connection array as a dynamic smartlist_t, rather than as
      a fixed-sized array. This is important, as the number of connections
      is becoming increasingly decoupled from the number of sockets.


Changes in version 0.1.2.14 - 2007-05-25
  Tor 0.1.2.14 changes the addresses of two directory authorities (this
  change especially affects those who serve or use hidden services),
  and fixes several other crash- and security-related bugs.

  o Directory authority changes:
    - Two directory authorities (moria1 and moria2) just moved to new
      IP addresses. This change will particularly affect those who serve
      or use hidden services.

  o Major bugfixes (crashes):
    - If a directory server runs out of space in the connection table
      as it's processing a begin_dir request, it will free the exit stream
      but leave it attached to the circuit, leading to unpredictable
      behavior. (Reported by seeess, fixes bug 425.)
    - Fix a bug in dirserv_remove_invalid() that would cause authorities
      to corrupt memory under some really unlikely scenarios.
    - Tighten router parsing rules. (Bugs reported by Benedikt Boss.)
    - Avoid segfaults when reading from mmaped descriptor file. (Reported
      by lodger.)

  o Major bugfixes (security):
    - When choosing an entry guard for a circuit, avoid using guards
      that are in the same family as the chosen exit -- not just guards
      that are exactly the chosen exit. (Reported by lodger.)

  o Major bugfixes (resource management):
    - If a directory authority is down, skip it when deciding where to get
      networkstatus objects or descriptors. Otherwise we keep asking
      every 10 seconds forever. Fixes bug 384.
    - Count it as a failure if we fetch a valid network-status but we
      don't want to keep it. Otherwise we'll keep fetching it and keep
      not wanting to keep it. Fixes part of bug 422.
    - If all of our dirservers have given us bad or no networkstatuses
      lately, then stop hammering them once per minute even when we
      think they're failed. Fixes another part of bug 422.

  o Minor bugfixes:
    - Actually set the purpose correctly for descriptors inserted with
      purpose=controller.
    - When we have k non-v2 authorities in our DirServer config,
      we ignored the last k authorities in the list when updating our
      network-statuses.
    - Correctly back-off from requesting router descriptors that we are
      having a hard time downloading.
    - Read resolv.conf files correctly on platforms where read() returns
      partial results on small file reads.
    - Don't rebuild the entire router store every time we get 32K of
      routers: rebuild it when the journal gets very large, or when
      the gaps in the store get very large.

  o Minor features:
    - When routers publish SVN revisions in their router descriptors,
      authorities now include those versions correctly in networkstatus
      documents.
    - Warn when using a version of libevent before 1.3b to run a server on
      OSX or BSD: these versions interact badly with userspace threads.


Changes in version 0.1.2.13 - 2007-04-24
  This release features some major anonymity fixes, such as safer path
  selection; better client performance; faster bootstrapping, better
  address detection, and better DNS support for servers; write limiting as
  well as read limiting to make servers easier to run; and a huge pile of
  other features and bug fixes. The bundles also ship with Vidalia 0.0.11.

  Tor 0.1.2.13 is released in memory of Rob Levin (1955-2006), aka lilo
  of the Freenode IRC network, remembering his patience and vision for
  free speech on the Internet.

  o Minor fixes:
    - Fix a memory leak when we ask for "all" networkstatuses and we
      get one we don't recognize.
    - Add more asserts to hunt down bug 417.
    - Disable kqueue on OS X 10.3 and earlier, to fix bug 371.


Changes in version 0.1.2.12-rc - 2007-03-16
  o Major bugfixes:
    - Fix an infinite loop introduced in 0.1.2.7-alpha when we serve
      directory information requested inside Tor connections (i.e. via
      begin_dir cells). It only triggered when the same connection was
      serving other data at the same time. Reported by seeess.

  o Minor bugfixes:
    - When creating a circuit via the controller, send a 'launched'
      event when we're done, so we follow the spec better.


Changes in version 0.1.2.11-rc - 2007-03-15
  o Minor bugfixes (controller), reported by daejees:
    - Correct the control spec to match how the code actually responds
      to 'getinfo addr-mappings/*'.
    - The control spec described a GUARDS event, but the code
      implemented a GUARD event. Standardize on GUARD, but let people
      ask for GUARDS too.


Changes in version 0.1.2.10-rc - 2007-03-07
  o Major bugfixes (Windows):
    - Do not load the NT services library functions (which may not exist)
      just to detect if we're a service trying to shut down. Now we run
      on Win98 and friends again.

  o Minor bugfixes (other):
    - Clarify a couple of log messages.
    - Fix a misleading socks5 error number.


Changes in version 0.1.2.9-rc - 2007-03-02
  o Major bugfixes (Windows):
    - On MinGW, use "%I64u" to printf/scanf 64-bit integers, instead
      of the usual GCC "%llu". This prevents a bug when saving 64-bit
      int configuration values: the high-order 32 bits would get
      truncated. In particular, we were being bitten by the default
      MaxAdvertisedBandwidth of 128 TB turning into 0. (Fixes bug 400
      and maybe also bug 397.)

  o Minor bugfixes (performance):
    - Use OpenSSL's AES implementation on platforms where it's faster.
      This could save us as much as 10% CPU usage.

  o Minor bugfixes (server):
    - Do not rotate onion key immediately after setting it for the first
      time.

  o Minor bugfixes (directory authorities):
    - Stop calling servers that have been hibernating for a long time
      "stable". Also, stop letting hibernating or obsolete servers affect
      uptime and bandwidth cutoffs.
    - Stop listing hibernating servers in the v1 directory.

  o Minor bugfixes (hidden services):
    - Upload hidden service descriptors slightly less often, to reduce
      load on authorities.

  o Minor bugfixes (other):
    - Fix an assert that could trigger if a controller quickly set then
      cleared EntryNodes. Bug found by Udo van den Heuvel.
    - On architectures where sizeof(int)>4, still clamp declarable bandwidth
      to INT32_MAX.
    - Fix a potential race condition in the rpm installer. Found by
      Stefan Nordhausen.
    - Try to fix eventdns warnings once and for all: do not treat a dns rcode
      of 2 as indicating that the server is completely bad; it sometimes
      means that the server is just bad for the request in question. (may fix
      the last of bug 326.)
    - Disable encrypted directory connections when we don't have a server
      descriptor for the destination. We'll get this working again in
      the 0.2.0 branch.


Changes in version 0.1.2.8-beta - 2007-02-26
  o Major bugfixes (crashes):
    - Stop crashing when the controller asks us to resetconf more than
      one config option at once. (Vidalia 0.0.11 does this.)
    - Fix a crash that happened on Win98 when we're given command-line
      arguments: don't try to load NT service functions from advapi32.dll
      except when we need them. (Bug introduced in 0.1.2.7-alpha;
      resolves bug 389.)
    - Fix a longstanding obscure crash bug that could occur when
      we run out of DNS worker processes. (Resolves bug 390.)

  o Major bugfixes (hidden services):
    - Correctly detect whether hidden service descriptor downloads are
      in-progress. (Suggested by Karsten Loesing; fixes bug 399.)

  o Major bugfixes (accounting):
    - When we start during an accounting interval before it's time to wake
      up, remember to wake up at the correct time. (May fix bug 342.)

  o Minor bugfixes (controller):
    - Give the controller END_STREAM_REASON_DESTROY events _before_ we
      clear the corresponding on_circuit variable, and remember later
      that we don't need to send a redundant CLOSED event. Resolves part
      3 of bug 367.
    - Report events where a resolve succeeded or where we got a socks
      protocol error correctly, rather than calling both of them
      "INTERNAL".
    - Change reported stream target addresses to IP consistently when
      we finally get the IP from an exit node.
    - Send log messages to the controller even if they happen to be very
      long.

  o Minor bugfixes (other):
    - Display correct results when reporting which versions are
      recommended, and how recommended they are. (Resolves bug 383.)
    - Improve our estimates for directory bandwidth to be less random:
      guess that an unrecognized directory will have the average bandwidth
      from all known directories, not that it will have the average
      bandwidth from those directories earlier than it on the list.
    - If we start a server with ClientOnly 1, then set ClientOnly to 0
      and hup, stop triggering an assert based on an empty onion_key.
    - On platforms with no working mmap() equivalent, don't warn the
      user when cached-routers doesn't exist.
    - Warn the user when mmap() [or its equivalent] fails for some reason
      other than file-not-found.
    - Don't warn the user when cached-routers.new doesn't exist: that's
      perfectly fine when starting up for the first time.
    - When EntryNodes are configured, rebuild the guard list to contain,
      in order: the EntryNodes that were guards before; the rest of the
      EntryNodes; the nodes that were guards before.
    - Mask out all signals in sub-threads; only the libevent signal
      handler should be processing them. This should prevent some crashes
      on some machines using pthreads. (Patch from coderman.)
    - Fix switched arguments on memset in the implementation of
      tor_munmap() for systems with no mmap() call.
    - When Tor receives a router descriptor that it asked for, but
      no longer wants (because it has received fresh networkstatuses
      in the meantime), do not warn the user. Cache the descriptor if
      we're a cache; drop it if we aren't.
    - Make earlier entry guards _really_ get retried when the network
      comes back online.
    - On a malformed DNS reply, always give an error to the corresponding
      DNS request.
    - Build with recent libevents on platforms that do not define the
      nonstandard types "u_int8_t" and friends.

  o Minor features (controller):
    - Warn the user when an application uses the obsolete binary v0
      control protocol. We're planning to remove support for it during
      the next development series, so it's good to give people some
      advance warning.
    - Add STREAM_BW events to report per-entry-stream bandwidth
      use. (Patch from Robert Hogan.)
    - Rate-limit SIGNEWNYM signals in response to controllers that
      impolitely generate them for every single stream. (Patch from
      mwenge; closes bug 394.)
    - Make REMAP stream events have a SOURCE (cache or exit), and
      make them generated in every case where we get a successful
      connected or resolved cell.

  o Minor bugfixes (performance):
    - Call router_have_min_dir_info half as often. (This is showing up in
      some profiles, but not others.)
    - When using GCC, make log_debug never get called at all, and its
      arguments never get evaluated, when no debug logs are configured.
      (This is showing up in some profiles, but not others.)

  o Minor features:
    - Remove some never-implemented options. Mark PathlenCoinWeight as
      obsolete.
    - Implement proposal 106: Stop requiring clients to have well-formed
      certificates; stop checking nicknames in certificates. (Clients
      have certificates so that they can look like Tor servers, but in
      the future we might want to allow them to look like regular TLS
      clients instead. Nicknames in certificates serve no purpose other
      than making our protocol easier to recognize on the wire.)
    - Revise messages on handshake failure again to be even more clear about
      which are incoming connections and which are outgoing.
    - Discard any v1 directory info that's over 1 month old (for
      directories) or over 1 week old (for running-routers lists).
    - Do not warn when individual nodes in the configuration's EntryNodes,
      ExitNodes, etc are down: warn only when all possible nodes
      are down. (Fixes bug 348.)
    - Always remove expired routers and networkstatus docs before checking
      whether we have enough information to build circuits. (Fixes
      bug 373.)
    - Put a lower-bound on MaxAdvertisedBandwidth.


Changes in version 0.1.2.7-alpha - 2007-02-06
  o Major bugfixes (rate limiting):
    - Servers decline directory requests much more aggressively when
      they're low on bandwidth. Otherwise they end up queueing more and
      more directory responses, which can't be good for latency.
    - But never refuse directory requests from local addresses.
    - Fix a memory leak when sending a 503 response for a networkstatus
      request.
    - Be willing to read or write on local connections (e.g. controller
      connections) even when the global rate limiting buckets are empty.
    - If our system clock jumps back in time, don't publish a negative
      uptime in the descriptor. Also, don't let the global rate limiting
      buckets go absurdly negative.
    - Flush local controller connection buffers periodically as we're
      writing to them, so we avoid queueing 4+ megabytes of data before
      trying to flush.

  o Major bugfixes (NT services):
    - Install as NT_AUTHORITY\LocalService rather than as SYSTEM; add a
      command-line flag so that admins can override the default by saying
      "tor --service install --user "SomeUser"". This will not affect
      existing installed services. Also, warn the user that the service
      will look for its configuration file in the service user's
      %appdata% directory. (We can't do the 'hardwire the user's appdata
      directory' trick any more, since we may not have read access to that
      directory.)

  o Major bugfixes (other):
    - Previously, we would cache up to 16 old networkstatus documents
      indefinitely, if they came from nontrusted authorities. Now we
      discard them if they are more than 10 days old.
    - Fix a crash bug in the presence of DNS hijacking (reported by Andrew
      Del Vecchio).
    - Detect and reject malformed DNS responses containing circular
      pointer loops.
    - If exits are rare enough that we're not marking exits as guards,
      ignore exit bandwidth when we're deciding the required bandwidth
      to become a guard.
    - When we're handling a directory connection tunneled over Tor,
      don't fill up internal memory buffers with all the data we want
      to tunnel; instead, only add it if the OR connection that will
      eventually receive it has some room for it. (This can lead to
      slowdowns in tunneled dir connections; a better solution will have
      to wait for 0.2.0.)

  o Minor bugfixes (dns):
    - Add some defensive programming to eventdns.c in an attempt to catch
      possible memory-stomping bugs.
    - Detect and reject DNS replies containing IPv4 or IPv6 records with
      an incorrect number of bytes. (Previously, we would ignore the
      extra bytes.)
    - Fix as-yet-unused reverse IPv6 lookup code so it sends nybbles
      in the correct order, and doesn't crash.
    - Free memory held in recently-completed DNS lookup attempts on exit.
      This was not a memory leak, but may have been hiding memory leaks.
    - Handle TTL values correctly on reverse DNS lookups.
    - Treat failure to parse resolv.conf as an error.

  o Minor bugfixes (other):
    - Fix crash with "tor --list-fingerprint" (reported by seeess).
    - When computing clock skew from directory HTTP headers, consider what
      time it was when we finished asking for the directory, not what
      time it is now.
    - Expire socks connections if they spend too long waiting for the
      handshake to finish. Previously we would let them sit around for
      days, if the connecting application didn't close them either.
    - And if the socks handshake hasn't started, don't send a
      "DNS resolve socks failed" handshake reply; just close it.
    - Stop using C functions that OpenBSD's linker doesn't like.
    - Don't launch requests for descriptors unless we have networkstatuses
      from at least half of the authorities. This delays the first
      download slightly under pathological circumstances, but can prevent
      us from downloading a bunch of descriptors we don't need.
    - Do not log IPs with TLS failures for incoming TLS
      connections. (Fixes bug 382.)
    - If the user asks to use invalid exit nodes, be willing to use
      unstable ones.
    - Stop using the reserved ac_cv namespace in our configure script.
    - Call stat() slightly less often; use fstat() when possible.
    - Refactor the way we handle pending circuits when an OR connection
      completes or fails, in an attempt to fix a rare crash bug.
    - Only rewrite a conn's address based on X-Forwarded-For: headers
      if it's a parseable public IP address; and stop adding extra quotes
      to the resulting address.

  o Major features:
    - Weight directory requests by advertised bandwidth. Now we can
      let servers enable write limiting but still allow most clients to
      succeed at their directory requests. (We still ignore weights when
      choosing a directory authority; I hope this is a feature.)

  o Minor features:
    - Create a new file ReleaseNotes which was the old ChangeLog. The
      new ChangeLog file now includes the summaries for all development
      versions too.
    - Check for addresses with invalid characters at the exit as well
      as at the client, and warn less verbosely when they fail. You can
      override this by setting ServerDNSAllowNonRFC953Addresses to 1.
    - Adapt a patch from goodell to let the contrib/exitlist script
      take arguments rather than require direct editing.
    - Inform the server operator when we decide not to advertise a
      DirPort due to AccountingMax enabled or a low BandwidthRate. It
      was confusing Zax, so now we're hopefully more helpful.
    - Bring us one step closer to being able to establish an encrypted
      directory tunnel without knowing a descriptor first. Still not
      ready yet. As part of the change, now assume we can use a
      create_fast cell if we don't know anything about a router.
    - Allow exit nodes to use nameservers running on ports other than 53.
    - Servers now cache reverse DNS replies.
    - Add an --ignore-missing-torrc command-line option so that we can
      get the "use sensible defaults if the configuration file doesn't
      exist" behavior even when specifying a torrc location on the command
      line.

  o Minor features (controller):
    - Track reasons for OR connection failure; make these reasons
      available via the controller interface. (Patch from Mike Perry.)
    - Add a SOCKS_BAD_HOSTNAME client status event so controllers
      can learn when clients are sending malformed hostnames to Tor.
    - Clean up documentation for controller status events.
    - Add a REMAP status to stream events to note that a stream's
      address has changed because of a cached address or a MapAddress
      directive.


Changes in version 0.1.2.6-alpha - 2007-01-09
  o Major bugfixes:
    - Fix an assert error introduced in 0.1.2.5-alpha: if a single TLS
      connection handles more than 4 gigs in either direction, we crash.
    - Fix an assert error introduced in 0.1.2.5-alpha: if we're an
      advertised exit node, somebody might try to exit from us when
      we're bootstrapping and before we've built our descriptor yet.
      Refuse the connection rather than crashing.

  o Minor bugfixes:
    - Warn if we (as a server) find that we've resolved an address that we
      weren't planning to resolve.
    - Warn that using select() on any libevent version before 1.1 will be
      unnecessarily slow (even for select()).
    - Flush ERR-level controller status events just like we currently
      flush ERR-level log events, so that a Tor shutdown doesn't prevent
      the controller from learning about current events.

  o Minor features (more controller status events):
    - Implement EXTERNAL_ADDRESS server status event so controllers can
      learn when our address changes.
    - Implement BAD_SERVER_DESCRIPTOR server status event so controllers
      can learn when directories reject our descriptor.
    - Implement SOCKS_UNKNOWN_PROTOCOL client status event so controllers
      can learn when a client application is speaking a non-socks protocol
      to our SocksPort.
    - Implement DANGEROUS_SOCKS client status event so controllers
      can learn when a client application is leaking DNS addresses.
    - Implement BUG general status event so controllers can learn when
      Tor is unhappy about its internal invariants.
    - Implement CLOCK_SKEW general status event so controllers can learn
      when Tor thinks the system clock is set incorrectly.
    - Implement GOOD_SERVER_DESCRIPTOR and ACCEPTED_SERVER_DESCRIPTOR
      server status events so controllers can learn when their descriptors
      are accepted by a directory.
    - Implement CHECKING_REACHABILITY and REACHABILITY_{SUCCEEDED|FAILED}
      server status events so controllers can learn about Tor's progress in
      deciding whether it's reachable from the outside.
    - Implement BAD_LIBEVENT general status event so controllers can learn
      when we have a version/method combination in libevent that needs to
      be changed.
    - Implement NAMESERVER_STATUS, NAMESERVER_ALL_DOWN, DNS_HIJACKED,
      and DNS_USELESS server status events so controllers can learn
      about changes to DNS server status.

  o Minor features (directory):
    - Authorities no longer recommend exits as guards if this would shift
      too much load to the exit nodes.


Changes in version 0.1.2.5-alpha - 2007-01-06
  o Major features:
    - Enable write limiting as well as read limiting. Now we sacrifice
      capacity if we're pushing out lots of directory traffic, rather
      than overrunning the user's intended bandwidth limits.
    - Include TLS overhead when counting bandwidth usage; previously, we
      would count only the bytes sent over TLS, but not the bytes used
      to send them.
    - Support running the Tor service with a torrc not in the same
      directory as tor.exe and default to using the torrc located in
      the %appdata%\Tor\ of the user who installed the service. Patch
      from Matt Edman.
    - Servers now check for the case when common DNS requests are going to
      wildcarded addresses (i.e. all getting the same answer), and change
      their exit policy to reject *:* if it's happening.
    - Implement BEGIN_DIR cells, so we can connect to the directory
      server via TLS to do encrypted directory requests rather than
      plaintext. Enable via the TunnelDirConns and PreferTunneledDirConns
      config options if you like.

  o Minor features (config and docs):
    - Start using the state file to store bandwidth accounting data:
      the bw_accounting file is now obsolete. We'll keep generating it
      for a while for people who are still using 0.1.2.4-alpha.
    - Try to batch changes to the state file so that we do as few
      disk writes as possible while still storing important things in
      a timely fashion.
    - The state file and the bw_accounting file get saved less often when
      the AvoidDiskWrites config option is set.
    - Make PIDFile work on Windows (untested).
    - Add internal descriptions for a bunch of configuration options:
      accessible via controller interface and in comments in saved
      options files.
    - Reject *:563 (NNTPS) in the default exit policy. We already reject
      NNTP by default, so this seems like a sensible addition.
    - Clients now reject hostnames with invalid characters. This should
      avoid some inadvertent info leaks. Add an option
      AllowNonRFC953Hostnames to disable this behavior, in case somebody
      is running a private network with hosts called @, !, and #.
    - Add a maintainer script to tell us which options are missing
      documentation: "make check-docs".
    - Add a new address-spec.txt document to describe our special-case
      addresses: .exit, .onion, and .noconnnect.

  o Minor features (DNS):
    - Ongoing work on eventdns infrastructure: now it has dns server
      and ipv6 support. One day Tor will make use of it.
    - Add client-side caching for reverse DNS lookups.
    - Add support to tor-resolve tool for reverse lookups and SOCKS5.
    - When we change nameservers or IP addresses, reset and re-launch
      our tests for DNS hijacking.

  o Minor features (directory):
    - Authorities now specify server versions in networkstatus. This adds
      about 2% to the size of compressed networkstatus docs, and allows
      clients to tell which servers support BEGIN_DIR and which don't.
      The implementation is forward-compatible with a proposed future
      protocol version scheme not tied to Tor versions.
    - DirServer configuration lines now have an orport= option so
      clients can open encrypted tunnels to the authorities without
      having downloaded their descriptors yet. Enabled for moria1,
      moria2, tor26, and lefkada now in the default configuration.
    - Directory servers are more willing to send a 503 "busy" if they
      are near their write limit, especially for v1 directory requests.
      Now they can use their limited bandwidth for actual Tor traffic.
    - Clients track responses with status 503 from dirservers. After a
      dirserver has given us a 503, we try not to use it until an hour has
      gone by, or until we have no dirservers that haven't given us a 503.
    - When we get a 503 from a directory, and we're not a server, we don't
      count the failure against the total number of failures allowed
      for the thing we're trying to download.
    - Report X-Your-Address-Is correctly from tunneled directory
      connections; don't report X-Your-Address-Is when it's an internal
      address; and never believe reported remote addresses when they're
      internal.
    - Protect against an unlikely DoS attack on directory servers.
    - Add a BadDirectory flag to network status docs so that authorities
      can (eventually) tell clients about caches they believe to be
      broken.

  o Minor features (controller):
    - Have GETINFO dir/status/* work on hosts with DirPort disabled.
    - Reimplement GETINFO so that info/names stays in sync with the
      actual keys.
    - Implement "GETINFO fingerprint".
    - Implement "SETEVENTS GUARD" so controllers can get updates on
      entry guard status as it changes.

  o Minor features (clean up obsolete pieces):
    - Remove some options that have been deprecated since at least
      0.1.0.x: AccountingMaxKB, LogFile, DebugLogFile, LogLevel, and
      SysLog. Use AccountingMax instead of AccountingMaxKB, and use Log
      to set log options.
    - We no longer look for identity and onion keys in "identity.key" and
      "onion.key" -- these were replaced by secret_id_key and
      secret_onion_key in 0.0.8pre1.
    - We no longer require unrecognized directory entries to be
      preceded by "opt".

  o Major bugfixes (security):
    - Stop sending the HttpProxyAuthenticator string to directory
      servers when directory connections are tunnelled through Tor.
    - Clients no longer store bandwidth history in the state file.
    - Do not log introduction points for hidden services if SafeLogging
      is set.
    - When generating bandwidth history, round down to the nearest
      1k. When storing accounting data, round up to the nearest 1k.
    - When we're running as a server, remember when we last rotated onion
      keys, so that we will rotate keys once they're a week old even if
      we never stay up for a week ourselves.

  o Major bugfixes (other):
    - Fix a longstanding bug in eventdns that prevented the count of
      timed-out resolves from ever being reset. This bug caused us to
      give up on a nameserver the third time it timed out, and try it
      10 seconds later... and to give up on it every time it timed out
      after that.
    - Take out the '5 second' timeout from the connection retry
      schedule. Now the first connect attempt will wait a full 10
      seconds before switching to a new circuit. Perhaps this will help
      a lot. Based on observations from Mike Perry.
    - Fix a bug on the Windows implementation of tor_mmap_file() that
      would prevent the cached-routers file from ever loading. Reported
      by John Kimble.

  o Minor bugfixes:
    - Fix an assert failure when a directory authority sets
      AuthDirRejectUnlisted and then receives a descriptor from an
      unlisted router. Reported by seeess.
    - Avoid a double-free when parsing malformed DirServer lines.
    - Fix a bug when a BSD-style PF socket is first used. Patch from
      Fabian Keil.
    - Fix a bug in 0.1.2.2-alpha that prevented clients from asking
      to resolve an address at a given exit node even when they ask for
      it by name.
    - Servers no longer ever list themselves in their "family" line,
      even if configured to do so. This makes it easier to configure
      family lists conveniently.
    - When running as a server, don't fall back to 127.0.0.1 when no
      nameservers are configured in /etc/resolv.conf; instead, make the
      user fix resolv.conf or specify nameservers explicitly. (Resolves
      bug 363.)
    - Stop accepting certain malformed ports in configured exit policies.
    - Don't re-write the fingerprint file every restart, unless it has
      changed.
    - Stop warning when a single nameserver fails: only warn when _all_ of
      our nameservers have failed. Also, when we only have one nameserver,
      raise the threshold for deciding that the nameserver is dead.
    - Directory authorities now only decide that routers are reachable
      if their identity keys are as expected.
    - When the user uses bad syntax in the Log config line, stop
      suggesting other bad syntax as a replacement.
    - Correctly detect ipv6 DNS capability on OpenBSD.

  o Minor bugfixes (controller):
    - Report the circuit number correctly in STREAM CLOSED events. Bug
      reported by Mike Perry.
    - Do not report bizarre values for results of accounting GETINFOs
      when the last second's write or read exceeds the allotted bandwidth.
    - Report "unrecognized key" rather than an empty string when the
      controller tries to fetch a networkstatus that doesn't exist.


Changes in version 0.1.1.26 - 2006-12-14
  o Security bugfixes:
    - Stop sending the HttpProxyAuthenticator string to directory
      servers when directory connections are tunnelled through Tor.
    - Clients no longer store bandwidth history in the state file.
    - Do not log introduction points for hidden services if SafeLogging
      is set.

  o Minor bugfixes:
    - Fix an assert failure when a directory authority sets
      AuthDirRejectUnlisted and then receives a descriptor from an
      unlisted router (reported by seeess).


Changes in version 0.1.2.4-alpha - 2006-12-03
  o Major features:
    - Add support for using natd; this allows FreeBSDs earlier than
      5.1.2 to have ipfw send connections through Tor without using
      SOCKS. (Patch from Zajcev Evgeny with tweaks from tup.)

  o Minor features:
    - Make all connections to addresses of the form ".noconnect"
      immediately get closed. This lets application/controller combos
      successfully test whether they're talking to the same Tor by
      watching for STREAM events.
    - Make cross.sh cross-compilation script work even when autogen.sh
      hasn't been run. (Patch from Michael Mohr.)
    - Statistics dumped by -USR2 now include a breakdown of public key
      operations, for profiling.

  o Major bugfixes:
    - Fix a major leak when directory authorities parse their
      approved-routers list, a minor memory leak when we fail to pick
      an exit node, and a few rare leaks on errors.
    - Handle TransPort connections even when the server sends data before
      the client sends data. Previously, the connection would just hang
      until the client sent data. (Patch from tup based on patch from
      Zajcev Evgeny.)
    - Avoid assert failure when our cached-routers file is empty on
      startup.

  o Minor bugfixes:
    - Don't log spurious warnings when we see a circuit close reason we
      don't recognize; it's probably just from a newer version of Tor.
    - Have directory authorities allow larger amounts of drift in uptime
      without replacing the server descriptor: previously, a server that
      restarted every 30 minutes could have 48 "interesting" descriptors
      per day.
    - Start linking to the Tor specification and Tor reference manual
      correctly in the Windows installer.
    - Add Vidalia to the OS X uninstaller script, so when we uninstall
      Tor/Privoxy we also uninstall Vidalia.
    - Resume building on Irix64, and fix a lot of warnings from its
      MIPSpro C compiler.
    - Don't corrupt last_guessed_ip in router_new_address_suggestion()
      when we're running as a client.


Changes in version 0.1.1.25 - 2006-11-04
  o Major bugfixes:
    - When a client asks us to resolve (rather than connect to)
      an address, and we have a cached answer, give them the cached
      answer. Previously, we would give them no answer at all.
    - We were building exactly the wrong circuits when we predict
      hidden service requirements, meaning Tor would have to build all
      its circuits on demand.
    - If none of our live entry guards have a high uptime, but we
      require a guard with a high uptime, try adding a new guard before
      we give up on the requirement. This patch should make long-lived
      connections more stable on average.
    - When testing reachability of our DirPort, don't launch new
      tests when there's already one in progress -- unreachable
      servers were stacking up dozens of testing streams.

  o Security bugfixes:
    - When the user sends a NEWNYM signal, clear the client-side DNS
      cache too. Otherwise we continue to act on previous information.

  o Minor bugfixes:
    - Avoid a memory corruption bug when creating a hash table for
      the first time.
    - Avoid possibility of controller-triggered crash when misusing
      certain commands from a v0 controller on platforms that do not
      handle printf("%s",NULL) gracefully.
    - Avoid infinite loop on unexpected controller input.
    - Don't log spurious warnings when we see a circuit close reason we
      don't recognize; it's probably just from a newer version of Tor.
    - Add Vidalia to the OS X uninstaller script, so when we uninstall
      Tor/Privoxy we also uninstall Vidalia.


Changes in version 0.1.2.3-alpha - 2006-10-29
  o Minor features:
    - Prepare for servers to publish descriptors less often: never
      discard a descriptor simply for being too old until either it is
      recommended by no authorities, or until we get a better one for
      the same router. Make caches consider retaining old recommended
      routers for even longer.
    - If most authorities set a BadExit flag for a server, clients
      don't think of it as a general-purpose exit. Clients only consider
      authorities that advertise themselves as listing bad exits.
    - Directory servers now provide 'Pragma: no-cache' and 'Expires'
      headers for content, so that we can work better in the presence of
      caching HTTP proxies.
    - Allow authorities to list nodes as bad exits by fingerprint or by
      address.

  o Minor features, controller:
    - Add a REASON field to CIRC events; for backward compatibility, this
      field is sent only to controllers that have enabled the extended
      event format. Also, add additional reason codes to explain why
      a given circuit has been destroyed or truncated. (Patches from
      Mike Perry)
    - Add a REMOTE_REASON field to extended CIRC events to tell the
      controller about why a remote OR told us to close a circuit.
    - Stream events also now have REASON and REMOTE_REASON fields,
      working much like those for circuit events.
    - There's now a GETINFO ns/... field so that controllers can ask Tor
      about the current status of a router.
    - A new event type "NS" to inform a controller when our opinion of
      a router's status has changed.
    - Add a GETINFO events/names and GETINFO features/names so controllers
      can tell which events and features are supported.
    - A new CLEARDNSCACHE signal to allow controllers to clear the
      client-side DNS cache without expiring circuits.

  o Security bugfixes:
    - When the user sends a NEWNYM signal, clear the client-side DNS
      cache too. Otherwise we continue to act on previous information.

  o Minor bugfixes:
    - Avoid sending junk to controllers or segfaulting when a controller
      uses EVENT_NEW_DESC with verbose nicknames.
    - Stop triggering asserts if the controller tries to extend hidden
      service circuits (reported by mwenge).
    - Avoid infinite loop on unexpected controller input.
    - When the controller does a "GETINFO network-status", tell it
      about even those routers whose descriptors are very old, and use
      long nicknames where appropriate.
    - Change NT service functions to be loaded on demand. This lets us
      build with MinGW without breaking Tor for Windows 98 users.
    - Do DirPort reachability tests less often, since a single test
      chews through many circuits before giving up.
    - In the hidden service example in torrc.sample, stop recommending
      esoteric and discouraged hidden service options.
    - When stopping an NT service, wait up to 10 sec for it to actually
      stop. Patch from Matt Edman; resolves bug 295.
    - Fix handling of verbose nicknames with ORCONN controller events:
      make them show up exactly when requested, rather than exactly when
      not requested.
    - When reporting verbose nicknames in entry_guards_getinfo(), avoid
      printing a duplicate "$" in the keys we send (reported by mwenge).
    - Correctly set maximum connection limit on Cygwin. (This time
      for sure!)
    - Try to detect Windows correctly when cross-compiling.
    - Detect the size of the routers file correctly even if it is
      corrupted (on systems without mmap) or not page-aligned (on systems
      with mmap). This bug was harmless.
    - Sometimes we didn't bother sending a RELAY_END cell when an attempt
      to open a stream fails; now we do in more cases. This should
      make clients able to find a good exit faster in some cases, since
      unhandleable requests will now get an error rather than timing out.
    - Resolve two memory leaks when rebuilding the on-disk router cache
      (reported by fookoowa).
    - Clean up minor code warnings suggested by the MIPSpro C compiler,
      and reported by some Centos users.
    - Controller signals now work on non-Unix platforms that don't define
      SIGUSR1 and SIGUSR2 the way we expect.
    - Patch from Michael Mohr to contrib/cross.sh, so it checks more
      values before failing, and always enables eventdns.
    - Libevent-1.2 exports, but does not define in its headers, strlcpy.
      Try to fix this in configure.in by checking for most functions
      before we check for libevent.


Changes in version 0.1.2.2-alpha - 2006-10-07
  o Major features:
    - Make our async eventdns library on-by-default for Tor servers,
      and plan to deprecate the separate dnsworker threads.
    - Add server-side support for "reverse" DNS lookups (using PTR
      records so clients can determine the canonical hostname for a given
      IPv4 address). Only supported by servers using eventdns; servers
      now announce in their descriptors whether they support eventdns.
    - Specify and implement client-side SOCKS5 interface for reverse DNS
      lookups (see doc/socks-extensions.txt).
    - Add a BEGIN_DIR relay cell type for an easier in-protocol way to
      connect to directory servers through Tor. Previously, clients needed
      to find Tor exits to make private connections to directory servers.
    - Avoid choosing Exit nodes for entry or middle hops when the
      total bandwidth available from non-Exit nodes is much higher than
      the total bandwidth available from Exit nodes.
    - Workaround for name servers (like Earthlink's) that hijack failing
      DNS requests and replace the no-such-server answer with a "helpful"
      redirect to an advertising-driven search portal. Also work around
      DNS hijackers who "helpfully" decline to hijack known-invalid
      RFC2606 addresses. Config option "ServerDNSDetectHijacking 0"
      lets you turn it off.
    - Send out a burst of long-range padding cells once we've established
      that we're reachable. Spread them over 4 circuits, so hopefully
      a few will be fast. This exercises our bandwidth and bootstraps
      us into the directory more quickly.

  o New/improved config options:
    - Add new config option "ResolvConf" to let the server operator
      choose an alternate resolve.conf file when using eventdns.
    - Add an "EnforceDistinctSubnets" option to control our "exclude
      servers on the same /16" behavior. It's still on by default; this
      is mostly for people who want to operate private test networks with
      all the machines on the same subnet.
    - If one of our entry guards is on the ExcludeNodes list, or the
      directory authorities don't think it's a good guard, treat it as
      if it were unlisted: stop using it as a guard, and throw it off
      the guards list if it stays that way for a long time.
    - Allow directory authorities to be marked separately as authorities
      for the v1 directory protocol, the v2 directory protocol, and
      as hidden service directories, to make it easier to retire old
      authorities. V1 authorities should set "HSAuthoritativeDir 1"
      to continue being hidden service authorities too.
    - Remove 8888 as a LongLivedPort, and add 6697 (IRCS).

  o Minor features, controller:
    - Fix CIRC controller events so that controllers can learn the
      identity digests of non-Named servers used in circuit paths.
    - Let controllers ask for more useful identifiers for servers. Instead
      of learning identity digests for un-Named servers and nicknames
      for Named servers, the new identifiers include digest, nickname,
      and indication of Named status. Off by default; see control-spec.txt
      for more information.
    - Add a "getinfo address" controller command so it can display Tor's
      best guess to the user.
    - New controller event to alert the controller when our server
      descriptor has changed.
    - Give more meaningful errors on controller authentication failure.

  o Minor features, other:
    - When asked to resolve a hostname, don't use non-exit servers unless
      requested to do so. This allows servers with broken DNS to be
      useful to the network.
    - Divide eventdns log messages into warn and info messages.
    - Reserve the nickname "Unnamed" for routers that can't pick
      a hostname: any router can call itself Unnamed; directory
      authorities will never allocate Unnamed to any particular router;
      clients won't believe that any router is the canonical Unnamed.
    - Only include function names in log messages for info/debug messages.
      For notice/warn/err, the content of the message should be clear on
      its own, and printing the function name only confuses users.
    - Avoid some false positives during reachability testing: don't try
      to test via a server that's on the same /24 as us.
    - If we fail to build a circuit to an intended enclave, and it's
      not mandatory that we use that enclave, stop wanting it.
    - When eventdns is enabled, allow multithreaded builds on NetBSD and
      OpenBSD. (We had previously disabled threads on these platforms
      because they didn't have working thread-safe resolver functions.)

  o Major bugfixes, anonymity/security:
    - If a client asked for a server by name, and there's a named server
      in our network-status but we don't have its descriptor yet, we
      could return an unnamed server instead.
    - Fix NetBSD bug that could allow someone to force uninitialized RAM
      to be sent to a server's DNS resolver. This only affects NetBSD
      and other platforms that do not bounds-check tolower().
    - Reject (most) attempts to use Tor circuits with length one. (If
      many people start using Tor as a one-hop proxy, exit nodes become
      a more attractive target for compromise.)
    - Just because your DirPort is open doesn't mean people should be
      able to remotely teach you about hidden service descriptors. Now
      only accept rendezvous posts if you've got HSAuthoritativeDir set.

  o Major bugfixes, other:
    - Don't crash on race condition in dns.c: tor_assert(!resolve->expire)
    - When a client asks the server to resolve (not connect to)
      an address, and it has a cached answer, give them the cached answer.
      Previously, the server would give them no answer at all.
    - Allow really slow clients to not hang up five minutes into their
      directory downloads (suggested by Adam J. Richter).
    - We were building exactly the wrong circuits when we anticipated
      hidden service requirements, meaning Tor would have to build all
      its circuits on demand.
    - Avoid crashing when we mmap a router cache file of size 0.
    - When testing reachability of our DirPort, don't launch new
      tests when there's already one in progress -- unreachable
      servers were stacking up dozens of testing streams.

  o Minor bugfixes, correctness:
    - If we're a directory mirror and we ask for "all" network status
      documents, we would discard status documents from authorities
      we don't recognize.
    - Avoid a memory corruption bug when creating a hash table for
      the first time.
    - Avoid controller-triggered crash when misusing certain commands
      from a v0 controller on platforms that do not handle
      printf("%s",NULL) gracefully.
    - Don't crash when a controller sends a third argument to an
      "extendcircuit" request.
    - Controller protocol fixes: fix encoding in "getinfo addr-mappings"
      response; fix error code when "getinfo dir/status/" fails.
    - Avoid crash when telling controller stream-status and a stream
      is detached.
    - Patch from Adam Langley to fix assert() in eventdns.c.
    - Fix a debug log message in eventdns to say "X resolved to Y"
      instead of "X resolved to X".
    - Make eventdns give strings for DNS errors, not just error numbers.
    - Track unreachable entry guards correctly: don't conflate
      'unreachable by us right now' with 'listed as down by the directory
      authorities'. With the old code, if a guard was unreachable by
      us but listed as running, it would clog our guard list forever.
    - Behave correctly in case we ever have a network with more than
      2GB/s total advertised capacity.
    - Make TrackExitHosts case-insensitive, and fix the behavior of
      ".suffix" TrackExitHosts items to avoid matching in the middle of
      an address.
    - Finally fix the openssl warnings from newer gccs that believe that
      ignoring a return value is okay, but casting a return value and
      then ignoring it is a sign of madness.
    - Prevent the contrib/exitlist script from printing the same
      result more than once.
    - Patch from Steve Hildrey: Generate network status correctly on
      non-versioning dirservers.
    - Don't listen to the X-Your-Address-Is hint if you did the lookup
      via Tor; otherwise you'll think you're the exit node's IP address.

  o Minor bugfixes, performance:
    - Two small performance improvements on parsing descriptors.
    - Major performance improvement on inserting descriptors: change
      algorithm from O(n^2) to O(n).
    - Make the common memory allocation path faster on machines where
      malloc(0) returns a pointer.
    - Start remembering X-Your-Address-Is directory hints even if you're
      a client, so you can become a server more smoothly.
    - Avoid duplicate entries on MyFamily line in server descriptor.

  o Packaging, features:
    - Remove architecture from OS X builds. The official builds are
      now universal binaries.
    - The Debian package now uses --verify-config when (re)starting,
      to distinguish configuration errors from other errors.
    - Update RPMs to require libevent 1.1b.

  o Packaging, bugfixes:
    - Patches so Tor builds with MinGW on Windows.
    - Patches so Tor might run on Cygwin again.
    - Resume building on non-gcc compilers and ancient gcc. Resume
      building with the -O0 compile flag. Resume building cleanly on
      Debian woody.
    - Run correctly on OS X platforms with case-sensitive filesystems.
    - Correct includes for net/if.h and net/pfvar.h on OpenBSD (from Tup).
    - Add autoconf checks so Tor can build on Solaris x86 again.

  o Documentation
    - Documented (and renamed) ServerDNSSearchDomains and
      ServerDNSResolvConfFile options.
    - Be clearer that the *ListenAddress directives can be repeated
      multiple times.


Changes in version 0.1.1.24 - 2006-09-29
  o Major bugfixes:
    - Allow really slow clients to not hang up five minutes into their
      directory downloads (suggested by Adam J. Richter).
    - Fix major performance regression from 0.1.0.x: instead of checking
      whether we have enough directory information every time we want to
      do something, only check when the directory information has changed.
      This should improve client CPU usage by 25-50%.
    - Don't crash if, after a server has been running for a while,
      it can't resolve its hostname.

  o Minor bugfixes:
    - Allow Tor to start when RunAsDaemon is set but no logs are set.
    - Don't crash when the controller receives a third argument to an
      "extendcircuit" request.
    - Controller protocol fixes: fix encoding in "getinfo addr-mappings"
      response; fix error code when "getinfo dir/status/" fails.
    - Fix configure.in to not produce broken configure files with
      more recent versions of autoconf. Thanks to Clint for his auto*
      voodoo.
    - Fix security bug on NetBSD that could allow someone to force
      uninitialized RAM to be sent to a server's DNS resolver. This
      only affects NetBSD and other platforms that do not bounds-check
      tolower().
    - Warn user when using libevent 1.1a or earlier with win32 or kqueue
      methods: these are known to be buggy.
    - If we're a directory mirror and we ask for "all" network status
      documents, we would discard status documents from authorities
      we don't recognize.


Changes in version 0.1.2.1-alpha - 2006-08-27
  o Major features:
    - Add "eventdns" async dns library from Adam Langley, tweaked to
      build on OSX and Windows. Only enabled if you pass the
      --enable-eventdns argument to configure.
    - Allow servers with no hostname or IP address to learn their
      IP address by asking the directory authorities. This code only
      kicks in when you would normally have exited with a "no address"
      error. Nothing's authenticated, so use with care.
    - Rather than waiting a fixed amount of time between retrying
      application connections, we wait only 5 seconds for the first,
      10 seconds for the second, and 15 seconds for each retry after
      that. Hopefully this will improve the expected user experience.
    - Patch from Tup to add support for transparent AP connections:
      this basically bundles the functionality of trans-proxy-tor
      into the Tor mainline. Now hosts with compliant pf/netfilter
      implementations can redirect TCP connections straight to Tor
      without diverting through SOCKS. Needs docs.
    - Busy directory servers save lots of memory by spooling server
      descriptors, v1 directories, and v2 networkstatus docs to buffers
      as needed rather than en masse. Also mmap the cached-routers
      files, so we don't need to keep the whole thing in memory too.
    - Automatically avoid picking more than one node from the same
      /16 network when constructing a circuit.
    - Revise and clean up the torrc.sample that we ship with; add
      a section for BandwidthRate and BandwidthBurst.

  o Minor features:
    - Split circuit_t into origin_circuit_t and or_circuit_t, and
      split connection_t into edge, or, dir, control, and base structs.
      These will save quite a bit of memory on busy servers, and they'll
      also help us track down bugs in the code and bugs in the spec.
    - Experimentally re-enable kqueue on OSX when using libevent 1.1b
      or later. Log when we are doing this, so we can diagnose it when
      it fails. (Also, recommend libevent 1.1b for kqueue and
      win32 methods; deprecate libevent 1.0b harder; make libevent
      recommendation system saner.)
    - Start being able to build universal binaries on OS X (thanks
      to Phobos).
    - Export the default exit policy via the control port, so controllers
      don't need to guess what it is / will be later.
    - Add a man page entry for ProtocolWarnings.
    - Add TestVia config option to the man page.
    - Remove even more protocol-related warnings from Tor server logs,
      such as bad TLS handshakes and malformed begin cells.
    - Stop fetching descriptors if you're not a dir mirror and you
      haven't tried to establish any circuits lately. [This currently
      causes some dangerous behavior, because when you start up again
      you'll use your ancient server descriptors.]
    - New DirPort behavior: if you have your dirport set, you download
      descriptors aggressively like a directory mirror, whether or not
      your ORPort is set.
    - Get rid of the router_retry_connections notion. Now routers
      no longer try to rebuild long-term connections to directory
      authorities, and directory authorities no longer try to rebuild
      long-term connections to all servers. We still don't hang up
      connections in these two cases though -- we need to look at it
      more carefully to avoid flapping, and we likely need to wait til
      0.1.1.x is obsolete.
    - Drop compatibility with obsolete Tors that permit create cells
      to have the wrong circ_id_type.
    - Re-enable per-connection rate limiting. Get rid of the "OP
      bandwidth" concept. Lay groundwork for "bandwidth classes" --
      separate global buckets that apply depending on what sort of conn
      it is.
    - Start publishing one minute or so after we find our ORPort
      to be reachable. This will help reduce the number of descriptors
      we have for ourselves floating around, since it's quite likely
      other things (e.g. DirPort) will change during that minute too.
    - Fork the v1 directory protocol into its own spec document,
      and mark dir-spec.txt as the currently correct (v2) spec.

  o Major bugfixes:
    - When we find our DirPort to be reachable, publish a new descriptor
      so we'll tell the world (reported by pnx).
    - Publish a new descriptor after we hup/reload. This is important
      if our config has changed such that we'll want to start advertising
      our DirPort now, etc.
    - Allow Tor to start when RunAsDaemon is set but no logs are set.
    - When we have a state file we cannot parse, tell the user and
      move it aside. Now we avoid situations where the user starts
      Tor in 1904, Tor writes a state file with that timestamp in it,
      the user fixes her clock, and Tor refuses to start.
    - Fix configure.in to not produce broken configure files with
      more recent versions of autoconf. Thanks to Clint for his auto*
      voodoo.
    - "tor --verify-config" now exits with -1(255) or 0 depending on
      whether the config options are bad or good.
    - Resolve bug 321 when using dnsworkers: append a period to every
      address we resolve at the exit node, so that we do not accidentally
      pick up local addresses, and so that failing searches are retried
      in the resolver search domains. (This is already solved for
      eventdns.) (This breaks Blossom servers for now.)
    - If we are using an exit enclave and we can't connect, e.g. because
      its webserver is misconfigured to not listen on localhost, then
      back off and try connecting from somewhere else before we fail.

  o Minor bugfixes:
    - Start compiling on MinGW on Windows (patches from Mike Chiussi).
    - Start compiling on MSVC6 on Windows (patches from Frediano Ziglio).
    - Fix bug 314: Tor clients issued "unsafe socks" warnings even
      when the IP address is mapped through MapAddress to a hostname.
    - Start passing "ipv4" hints to getaddrinfo(), so servers don't do
      useless IPv6 DNS resolves.
    - Patch suggested by Karsten Loesing: respond to SIGNAL command
      before we execute the signal, in case the signal shuts us down.
    - Clean up AllowInvalidNodes man page entry.
    - Claim a commonname of Tor, rather than TOR, in TLS handshakes.
    - Add more asserts to track down an assert error on a windows Tor
      server with connection_add being called with socket == -1.
    - Handle reporting OR_CONN_EVENT_NEW events to the controller.
    - Fix misleading log messages: an entry guard that is "unlisted",
      as well as not known to be "down" (because we've never heard
      of it), is not therefore "up".
    - Remove code to special-case "-cvs" ending, since it has not
      actually mattered since 0.0.9.
    - Make our socks5 handling more robust to broken socks clients:
      throw out everything waiting on the buffer in between socks
      handshake phases, since they can't possibly (so the theory
      goes) have predicted what we plan to respond to them.


Changes in version 0.1.1.23 - 2006-07-30
  o Major bugfixes:
    - Fast Tor servers, especially exit nodes, were triggering asserts
      due to a bug in handling the list of pending DNS resolves. Some
      bugs still remain here; we're hunting them.
    - Entry guards could crash clients by sending unexpected input.
    - More fixes on reachability testing: if you find yourself reachable,
      then don't ever make any client requests (so you stop predicting
      circuits), then hup or have your clock jump, then later your IP
      changes, you won't think circuits are working, so you won't try to
      test reachability, so you won't publish.

  o Minor bugfixes:
    - Avoid a crash if the controller does a resetconf firewallports
      and then a setconf fascistfirewall=1.
    - Avoid an integer underflow when the dir authority decides whether
      a router is stable: we might wrongly label it stable, and compute
      a slightly wrong median stability, when a descriptor is published
      later than now.
    - Fix a place where we might trigger an assert if we can't build our
      own server descriptor yet.


Changes in version 0.1.1.22 - 2006-07-05
  o Major bugfixes:
    - Fix a big bug that was causing servers to not find themselves
      reachable if they changed IP addresses. Since only 0.1.1.22+
      servers can do reachability testing correctly, now we automatically
      make sure to test via one of these.
    - Fix to allow clients and mirrors to learn directory info from
      descriptor downloads that get cut off partway through.
    - Directory authorities had a bug in deciding if a newly published
      descriptor was novel enough to make everybody want a copy -- a few
      servers seem to be publishing new descriptors many times a minute.
  o Minor bugfixes:
    - Fix a rare bug that was causing some servers to complain about
      "closing wedged cpuworkers" and skip some circuit create requests.
    - Make the Exit flag in directory status documents actually work.


Changes in version 0.1.1.21 - 2006-06-10
  o Crash and assert fixes from 0.1.1.20:
    - Fix a rare crash on Tor servers that have enabled hibernation.
    - Fix a seg fault on startup for Tor networks that use only one
      directory authority.
    - Fix an assert from a race condition that occurs on Tor servers
      while exiting, where various threads are trying to log that they're
      exiting, and delete the logs, at the same time.
    - Make our unit tests pass again on certain obscure platforms.

  o Other fixes:
    - Add support for building SUSE RPM packages.
    - Speed up initial bootstrapping for clients: if we are making our
      first ever connection to any entry guard, then don't mark it down
      right after that.
    - When only one Tor server in the network is labelled as a guard,
      and we've already picked him, we would cycle endlessly picking him
      again, being unhappy about it, etc. Now we specifically exclude
      current guards when picking a new guard.
    - Servers send create cells more reliably after the TLS connection
      is established: we were sometimes forgetting to send half of them
      when we had more than one pending.
    - If we get a create cell that asks us to extend somewhere, but the
      Tor server there doesn't match the expected digest, we now send
      a destroy cell back, rather than silently doing nothing.
    - Make options->RedirectExit work again.
    - Make cookie authentication for the controller work again.
    - Stop being picky about unusual characters in the arguments to
      mapaddress. It's none of our business.
    - Add a new config option "TestVia" that lets you specify preferred
      middle hops to use for test circuits. Perhaps this will let me
      debug the reachability problems better.

  o Log / documentation fixes:
    - If we're a server and some peer has a broken TLS certificate, don't
      log about it unless ProtocolWarnings is set, i.e., we want to hear
      about protocol violations by others.
    - Fix spelling of VirtualAddrNetwork in man page.
    - Add a better explanation at the top of the autogenerated torrc file
      about what happened to our old torrc.


Changes in version 0.1.1.20 - 2006-05-23
  o Bugfixes:
    - Downgrade a log severity where servers complain that they're
      invalid.
    - Avoid a compile warning on FreeBSD.
    - Remove string size limit on NEWDESC messages; solve bug 291.
    - Correct the RunAsDaemon entry in the man page; ignore RunAsDaemon
      more thoroughly when we're running on windows.


Changes in version 0.1.1.19-rc - 2006-05-03
  o Minor bugs:
    - Regenerate our local descriptor if it's dirty and we try to use
      it locally (e.g. if it changes during reachability detection).
    - If we setconf our ORPort to 0, we continued to listen on the
      old ORPort and receive connections.
    - Avoid a second warning about machine/limits.h on Debian
      GNU/kFreeBSD.
    - Be willing to add our own routerinfo into the routerlist.
      Now authorities will include themselves in their directories
      and network-statuses.
    - Stop trying to upload rendezvous descriptors to every
      directory authority: only try the v1 authorities.
    - Servers no longer complain when they think they're not
      registered with the directory authorities. There were too many
      false positives.
    - Backport dist-rpm changes so rpms can be built without errors.

  o Features:
    - Implement an option, VirtualAddrMask, to set which addresses
      get handed out in response to mapaddress requests. This works
      around a bug in tsocks where 127.0.0.0/8 is never socksified.


Changes in version 0.1.1.18-rc - 2006-04-10
  o Major fixes:
    - Work harder to download live network-statuses from all the
      directory authorities we know about. Improve the threshold
      decision logic so we're more robust to edge cases.
    - When fetching rendezvous descriptors, we were willing to ask
      v2 authorities too, which would always return 404.

  o Minor fixes:
    - Stop listing down or invalid nodes in the v1 directory. This will
      reduce its bulk by about 1/3, and reduce load on directory
      mirrors.
    - When deciding whether a router is Fast or Guard-worthy, consider
      his advertised BandwidthRate and not just the BandwidthCapacity.
    - No longer ship INSTALL and README files -- they are useless now.
    - Force rpmbuild to behave and honor target_cpu.
    - Avoid warnings about machine/limits.h on Debian GNU/kFreeBSD.
    - Start to include translated versions of the tor-doc-*.html
      files, along with the screenshots. Still needs more work.
    - Start sending back 512 and 451 errors if mapaddress fails,
      rather than not sending anything back at all.
    - When we fail to bind or listen on an incoming or outgoing
      socket, we should close it before failing. otherwise we just
      leak it. (thanks to weasel for finding.)
    - Allow "getinfo dir/status/foo" to work, as long as your DirPort
      is enabled. (This is a hack, and will be fixed in 0.1.2.x.)
    - Make NoPublish (even though deprecated) work again.
    - Fix a minor security flaw where a versioning auth dirserver
      could list a recommended version many times in a row to make
      clients more convinced that it's recommended.
    - Fix crash bug if there are two unregistered servers running
      with the same nickname, one of them is down, and you ask for
      them by nickname in your EntryNodes or ExitNodes. Also, try
      to pick the one that's running rather than an arbitrary one.
    - Fix an infinite loop we could hit if we go offline for too long.
    - Complain when we hit WSAENOBUFS on recv() or write() too.
      Perhaps this will help us hunt the bug.
    - If you're not a versioning dirserver, don't put the string
      "client-versions \nserver-versions \n" in your network-status.
    - Lower the minimum required number of file descriptors to 1000,
      so we can have some overhead for Valgrind on Linux, where the
      default ulimit -n is 1024.

  o New features:
    - Add tor.dizum.com as the fifth authoritative directory server.
    - Add a new config option FetchUselessDescriptors, off by default,
      for when you plan to run "exitlist" on your client and you want
      to know about even the non-running descriptors.


Changes in version 0.1.1.17-rc - 2006-03-28
  o Major fixes:
    - Clients and servers since 0.1.1.10-alpha have been expiring
      connections whenever they are idle for 5 minutes and they *do*
      have circuits on them. Oops. With this new version, clients will
      discard their previous entry guard choices and avoid choosing
      entry guards running these flawed versions.
    - Fix memory leak when uncompressing concatenated zlib streams. This
      was causing substantial leaks over time on Tor servers.
    - The v1 directory was including servers as much as 48 hours old,
      because that's how the new routerlist->routers works. Now only
      include them if they're 20 hours old or less.

  o Minor fixes:
    - Resume building on irix64, netbsd 2.0, etc.
    - On non-gcc compilers (e.g. solaris), use "-g -O" instead of
      "-Wall -g -O2".
    - Stop writing the "router.desc" file, ever. Nothing uses it anymore,
      and it is confusing some users.
    - Mirrors stop caching the v1 directory so often.
    - Make the max number of old descriptors that a cache will hold
      rise with the number of directory authorities, so we can scale.
    - Change our win32 uname() hack to be more forgiving about what
      win32 versions it thinks it's found.

  o New features:
    - Add lefkada.eecs.harvard.edu as a fourth authoritative directory
      server.
    - When the controller's *setconf commands fail, collect an error
      message in a string and hand it back to the controller.
    - Make the v2 dir's "Fast" flag based on relative capacity, just
      like "Stable" is based on median uptime. Name everything in the
      top 7/8 Fast, and only the top 1/2 gets to be a Guard.
    - Log server fingerprint on startup, so new server operators don't
      have to go hunting around their filesystem for it.
    - Return a robots.txt on our dirport to discourage google indexing.
    - Let the controller ask for GETINFO dir/status/foo so it can ask
      directly rather than connecting to the dir port. Only works when
      dirport is set for now.

  o New config options rather than constants in the code:
    - SocksTimeout: How long do we let a socks connection wait
      unattached before we fail it?
    - CircuitBuildTimeout: Cull non-open circuits that were born
      at least this many seconds ago.
    - CircuitIdleTimeout: Cull open clean circuits that were born
      at least this many seconds ago.


Changes in version 0.1.1.16-rc - 2006-03-18
  o Bugfixes on 0.1.1.15-rc:
    - Fix assert when the controller asks to attachstream a connect-wait
      or resolve-wait stream.
    - Now do address rewriting when the controller asks us to attach
      to a particular circuit too. This will let Blossom specify
      "moria2.exit" without having to learn what moria2's IP address is.
    - Make the "tor --verify-config" command-line work again, so people
      can automatically check if their torrc will parse.
    - Authoritative dirservers no longer require an open connection from
      a server to consider him "reachable". We need this change because
      when we add new auth dirservers, old servers won't know not to
      hang up on them.
    - Let Tor build on Sun CC again.
    - Fix an off-by-one buffer size in dirserv.c that magically never
      hit our three authorities but broke sjmurdoch's own tor network.
    - If we as a directory mirror don't know of any v1 directory
      authorities, then don't try to cache any v1 directories.
    - Stop warning about unknown servers in our family when they are
      given as hex digests.
    - Stop complaining as quickly to the server operator that he
      hasn't registered his nickname/key binding.
    - Various cleanups so we can add new V2 Auth Dirservers.
    - Change "AllowUnverifiedNodes" to "AllowInvalidNodes", to
      reflect the updated flags in our v2 dir protocol.
    - Resume allowing non-printable characters for exit streams (both
      for connecting and for resolving). Now we tolerate applications
      that don't follow the RFCs. But continue to block malformed names
      at the socks side.

  o Bugfixes on 0.1.0.x:
    - Fix assert bug in close_logs(): when we close and delete logs,
      remove them all from the global "logfiles" list.
    - Fix minor integer overflow in calculating when we expect to use up
      our bandwidth allocation before hibernating.
    - Fix a couple of bugs in OpenSSL detection. Also, deal better when
      there are multiple SSLs installed with different versions.
    - When we try to be a server and Address is not explicitly set and
      our hostname resolves to a private IP address, try to use an
      interface address if it has a public address. Now Windows machines
      that think of themselves as localhost can work by default.

  o New features:
    - Let the controller ask for GETINFO dir/server/foo so it can ask
      directly rather than connecting to the dir port.
    - Let the controller tell us about certain router descriptors
      that it doesn't want Tor to use in circuits. Implement
      SETROUTERPURPOSE and modify +POSTDESCRIPTOR to do this.
    - New config option SafeSocks to reject all application connections
      using unsafe socks protocols. Defaults to off.


Changes in version 0.1.1.15-rc - 2006-03-11
  o Bugfixes and cleanups:
    - When we're printing strings from the network, don't try to print
      non-printable characters. This protects us against shell escape
      sequence exploits, and also against attacks to fool humans into
      misreading their logs.
    - Fix a bug where Tor would fail to establish any connections if you
      left it off for 24 hours and then started it: we were happy with
      the obsolete network statuses, but they all referred to router
      descriptors that were too old to fetch, so we ended up with no
      valid router descriptors.
    - Fix a seg fault in the controller's "getinfo orconn-status"
      command while listing status on incoming handshaking connections.
      Introduce a status name "NEW" for these connections.
    - If we get a linelist or linelist_s config option from the torrc
      (e.g. ExitPolicy) and it has no value, warn and skip rather than
      silently resetting it to its default.
    - Don't abandon entry guards until they've been down or gone for
      a whole month.
    - Cleaner and quieter log messages.

  o New features:
    - New controller signal NEWNYM that makes new application requests
      use clean circuits.
    - Add a new circuit purpose 'controller' to let the controller ask
      for a circuit that Tor won't try to use. Extend the EXTENDCIRCUIT
      controller command to let you specify the purpose if you're
      starting a new circuit. Add a new SETCIRCUITPURPOSE controller
      command to let you change a circuit's purpose after it's been
      created.
    - Accept "private:*" in routerdesc exit policies; not generated yet
      because older Tors do not understand it.
    - Add BSD-style contributed startup script "rc.subr" from Peter
      Thoenen.


Changes in version 0.1.1.14-alpha - 2006-02-20
  o Bugfixes on 0.1.1.x:
    - Don't die if we ask for a stdout or stderr log (even implicitly)
      and we're set to RunAsDaemon -- just warn.
    - We still had a few bugs in the OR connection rotation code that
      caused directory servers to slowly aggregate connections to other
      fast Tor servers. This time for sure!
    - Make log entries on Win32 include the name of the function again.
    - We were treating a pair of exit policies if they were equal even
      if one said accept and the other said reject -- causing us to
      not always publish a new descriptor since we thought nothing
      had changed.
    - Retry pending server downloads as well as pending networkstatus
      downloads when we unexpectedly get a socks request.
    - We were ignoring the IS_FAST flag in the directory status,
      meaning we were willing to pick trivial-bandwidth nodes for "fast"
      connections.
    - If the controller's SAVECONF command fails (e.g. due to file
      permissions), let the controller know that it failed.

  o Features:
    - If we're trying to be a Tor server and running Windows 95/98/ME
      as a server, explain that we'll likely crash.
    - When we're a server, a client asks for an old-style directory,
      and our write bucket is empty, don't give it to him. This way
      small servers can continue to serve the directory *sometimes*,
      without getting overloaded.
    - Compress exit policies even more -- look for duplicate lines
      and remove them.
    - Clients now honor the "guard" flag in the router status when
      picking entry guards, rather than looking at is_fast or is_stable.
    - Retain unrecognized lines in $DATADIR/state file, so that we can
      be forward-compatible.
    - Generate 18.0.0.0/8 address policy format in descs when we can;
      warn when the mask is not reducible to a bit-prefix.
    - Let the user set ControlListenAddress in the torrc. This can be
      dangerous, but there are some cases (like a secured LAN) where it
      makes sense.
    - Split ReachableAddresses into ReachableDirAddresses and
      ReachableORAddresses, so we can restrict Dir conns to port 80
      and OR conns to port 443.
    - Now we can target arch and OS in rpm builds (contributed by
      Phobos). Also make the resulting dist-rpm filename match the
      target arch.
    - New config options to help controllers: FetchServerDescriptors
      and FetchHidServDescriptors for whether to fetch server
      info and hidserv info or let the controller do it, and
      PublishServerDescriptor and PublishHidServDescriptors.
    - Also let the controller set the __AllDirActionsPrivate config
      option if you want all directory fetches/publishes to happen via
      Tor (it assumes your controller bootstraps your circuits).


Changes in version 0.1.0.17 - 2006-02-17
  o Crash bugfixes on 0.1.0.x:
    - When servers with a non-zero DirPort came out of hibernation,
      sometimes they would trigger an assert.

  o Other important bugfixes:
    - On platforms that don't have getrlimit (like Windows), we were
      artificially constraining ourselves to a max of 1024
      connections. Now just assume that we can handle as many as 15000
      connections. Hopefully this won't cause other problems.

  o Backported features:
    - When we're a server, a client asks for an old-style directory,
      and our write bucket is empty, don't give it to him. This way
      small servers can continue to serve the directory *sometimes*,
      without getting overloaded.
    - Whenever you get a 503 in response to a directory fetch, try
      once more. This will become important once servers start sending
      503's whenever they feel busy.
    - Fetch a new directory every 120 minutes, not every 40 minutes.
      Now that we have hundreds of thousands of users running the old
      directory algorithm, it's starting to hurt a lot.
    - Bump up the period for forcing a hidden service descriptor upload
      from 20 minutes to 1 hour.


Changes in version 0.1.1.13-alpha - 2006-02-09
  o Crashes in 0.1.1.x:
    - When you tried to setconf ORPort via the controller, Tor would
      crash. So people using TorCP to become a server were sad.
    - Solve (I hope) the stack-smashing bug that we were seeing on fast
      servers. The problem appears to be something do with OpenSSL's
      random number generation, or how we call it, or something. Let me
      know if the crashes continue.
    - Turn crypto hardware acceleration off by default, until we find
      somebody smart who can test it for us. (It appears to produce
      seg faults in at least some cases.)
    - Fix a rare assert error when we've tried all intro points for
      a hidden service and we try fetching the service descriptor again:
      "Assertion conn->state != AP_CONN_STATE_RENDDESC_WAIT failed"

  o Major fixes:
    - Fix a major load balance bug: we were round-robining in 16 KB
      chunks, and servers with bandwidthrate of 20 KB, while downloading
      a 600 KB directory, would starve their other connections. Now we
      try to be a bit more fair.
    - Dir authorities and mirrors were never expiring the newest
      descriptor for each server, causing memory and directory bloat.
    - Fix memory-bloating and connection-bloating bug on servers: We
      were never closing any connection that had ever had a circuit on
      it, because we were checking conn->n_circuits == 0, yet we had a
      bug that let it go negative.
    - Make Tor work using squid as your http proxy again -- squid
      returns an error if you ask for a URL that's too long, and it uses
      a really generic error message. Plus, many people are behind a
      transparent squid so they don't even realize it.
    - On platforms that don't have getrlimit (like Windows), we were
      artificially constraining ourselves to a max of 1024
      connections. Now just assume that we can handle as many as 15000
      connections. Hopefully this won't cause other problems.
    - Add a new config option ExitPolicyRejectPrivate which defaults to
      1. This means all exit policies will begin with rejecting private
      addresses, unless the server operator explicitly turns it off.

  o Major features:
    - Clients no longer download descriptors for non-running
      descriptors.
    - Before we add new directory authorities, we should make it
      clear that only v1 authorities should receive/publish hidden
      service descriptors.

  o Minor features:
    - As soon as we've fetched some more directory info, immediately
      try to download more server descriptors. This way we don't have
      a 10 second pause during initial bootstrapping.
    - Remove even more loud log messages that the server operator can't
      do anything about.
    - When we're running an obsolete or un-recommended version, make
      the log message more clear about what the problem is and what
      versions *are* still recommended.
    - Provide a more useful warn message when our onion queue gets full:
      the CPU is too slow or the exit policy is too liberal.
    - Don't warn when we receive a 503 from a dirserver/cache -- this
      will pave the way for them being able to refuse if they're busy.
    - When we fail to bind a listener, try to provide a more useful
      log message: e.g., "Is Tor already running?"
    - Adjust tor-spec to parameterize cell and key lengths. Now Ian
      Goldberg can prove things about our handshake protocol more
      easily.
    - MaxConn has been obsolete for a while now. Document the ConnLimit
      config option, which is a *minimum* number of file descriptors
      that must be available else Tor refuses to start.
    - Apply Matt Ghali's --with-syslog-facility patch to ./configure
      if you log to syslog and want something other than LOG_DAEMON.
    - Make dirservers generate a separate "guard" flag to mean,
      "would make a good entry guard". Make clients parse it and vote
      on it. Not used by clients yet.
    - Implement --with-libevent-dir option to ./configure. Also, improve
      search techniques to find libevent, and use those for openssl too.
    - Bump the default bandwidthrate to 3 MB, and burst to 6 MB
    - Only start testing reachability once we've established a
      circuit. This will make startup on dirservers less noisy.
    - Don't try to upload hidden service descriptors until we have
      established a circuit.
    - Fix the controller's "attachstream 0" command to treat conn like
      it just connected, doing address remapping, handling .exit and
      .onion idioms, and so on. Now we're more uniform in making sure
      that the controller hears about new and closing connections.


Changes in version 0.1.1.12-alpha - 2006-01-11
  o Bugfixes on 0.1.1.x:
    - The fix to close duplicate server connections was closing all
      Tor client connections if they didn't establish a circuit
      quickly enough. Oops.
    - Fix minor memory issue (double-free) that happened on exit.

  o Bugfixes on 0.1.0.x:
    - Tor didn't warn when it failed to open a log file.


Changes in version 0.1.1.11-alpha - 2006-01-10
  o Crashes in 0.1.1.x:
    - Include all the assert/crash fixes from 0.1.0.16.
    - If you start Tor and then quit very quickly, there were some
      races that tried to free things that weren't allocated yet.
    - Fix a rare memory stomp if you're running hidden services.
    - Fix segfault when specifying DirServer in config without nickname.
    - Fix a seg fault when you finish connecting to a server but at
      that moment you dump his server descriptor.
    - Extendcircuit and Attachstream controller commands would
      assert/crash if you don't give them enough arguments.
    - Fix an assert error when we're out of space in the connection_list
      and we try to post a hidden service descriptor (reported by weasel).
    - If you specify a relative torrc path and you set RunAsDaemon in
      your torrc, then it chdir()'s to the new directory. If you HUP,
      it tries to load the new torrc location, fails, and exits.
      The fix: no longer allow a relative path to torrc using -f.

  o Major features:
    - Implement "entry guards": automatically choose a handful of entry
      nodes and stick with them for all circuits. Only pick new guards
      when the ones you have are unsuitable, and if the old guards
      become suitable again, switch back. This will increase security
      dramatically against certain end-point attacks. The EntryNodes
      config option now provides some hints about which entry guards you
      want to use most; and StrictEntryNodes means to only use those.
    - New directory logic: download by descriptor digest, not by
      fingerprint. Caches try to download all listed digests from
      authorities; clients try to download "best" digests from caches.
      This avoids partitioning and isolating attacks better.
    - Make the "stable" router flag in network-status be the median of
      the uptimes of running valid servers, and make clients pay
      attention to the network-status flags. Thus the cutoff adapts
      to the stability of the network as a whole, making IRC, IM, etc
      connections more reliable.

  o Major fixes:
    - Tor servers with dynamic IP addresses were needing to wait 18
      hours before they could start doing reachability testing using
      the new IP address and ports. This is because they were using
      the internal descriptor to learn what to test, yet they were only
      rebuilding the descriptor once they decided they were reachable.
    - Tor 0.1.1.9 and 0.1.1.10 had a serious bug that caused clients
      to download certain server descriptors, throw them away, and then
      fetch them again after 30 minutes. Now mirrors throw away these
      server descriptors so clients can't get them.
    - We were leaving duplicate connections to other ORs open for a week,
      rather than closing them once we detect a duplicate. This only
      really affected authdirservers, but it affected them a lot.
    - Spread the authdirservers' reachability testing over the entire
      testing interval, so we don't try to do 500 TLS's at once every
      20 minutes.

  o Minor fixes:
    - If the network is down, and we try to connect to a conn because
      we have a circuit in mind, and we timeout (30 seconds) because the
      network never answers, we were expiring the circuit, but we weren't
      obsoleting the connection or telling the entry_guards functions.
    - Some Tor servers process billions of cells per day. These statistics
      need to be uint64_t's.
    - Check for integer overflows in more places, when adding elements
      to smartlists. This could possibly prevent a buffer overflow
      on malicious huge inputs. I don't see any, but I haven't looked
      carefully.
    - ReachableAddresses kept growing new "reject *:*" lines on every
      setconf/reload.
    - When you "setconf log" via the controller, it should remove all
      logs. We were automatically adding back in a "log notice stdout".
    - Newly bootstrapped Tor networks couldn't establish hidden service
      circuits until they had nodes with high uptime. Be more tolerant.
    - We were marking servers down when they could not answer every piece
      of the directory request we sent them. This was far too harsh.
    - Fix the torify (tsocks) config file to not use Tor for localhost
      connections.
    - Directory authorities now go to the proper authority when asking for
      a networkstatus, even when they want a compressed one.
    - Fix a harmless bug that was causing Tor servers to log
      "Got an end because of misc error, but we're not an AP. Closing."
    - Authorities were treating their own descriptor changes as cosmetic,
      meaning the descriptor available in the network-status and the
      descriptor that clients downloaded were different.
    - The OS X installer was adding a symlink for tor_resolve but
      the binary was called tor-resolve (reported by Thomas Hardly).
    - Workaround a problem with some http proxies where they refuse GET
      requests that specify "Content-Length: 0" (reported by Adrian).
    - Fix wrong log message when you add a "HiddenServiceNodes" config
      line without any HiddenServiceDir line (reported by Chris Thomas).

  o Minor features:
    - Write the TorVersion into the state file so we have a prayer of
      keeping forward and backward compatibility.
    - Revive the FascistFirewall config option rather than eliminating it:
      now it's a synonym for ReachableAddresses *:80,*:443.
    - Clients choose directory servers from the network status lists,
      not from their internal list of router descriptors. Now they can
      go to caches directly rather than needing to go to authorities
      to bootstrap.
    - Directory authorities ignore router descriptors that have only
      cosmetic differences: do this for 0.1.0.x servers now too.
    - Add a new flag to network-status indicating whether the server
      can answer v2 directory requests too.
    - Authdirs now stop whining so loudly about bad descriptors that
      they fetch from other dirservers. So when there's a log complaint,
      it's for sure from a freshly uploaded descriptor.
    - Reduce memory requirements in our structs by changing the order
      of fields.
    - There used to be two ways to specify your listening ports in a
      server descriptor: on the "router" line and with a separate "ports"
      line. Remove support for the "ports" line.
    - New config option "AuthDirRejectUnlisted" for auth dirservers as
      a panic button: if we get flooded with unusable servers we can
      revert to only listing servers in the approved-routers file.
    - Auth dir servers can now mark a fingerprint as "!reject" or
      "!invalid" in the approved-routers file (as its nickname), to
      refuse descriptors outright or include them but marked as invalid.
    - Servers store bandwidth history across restarts/crashes.
    - Add reasons to DESTROY and RELAY_TRUNCATED cells, so clients can
      get a better idea of why their circuits failed. Not used yet.
    - Directory mirrors now cache up to 16 unrecognized network-status
      docs. Now we can add new authdirservers and they'll be cached too.
    - When picking a random directory, prefer non-authorities if any
      are known.
    - New controller option "getinfo desc/all-recent" to fetch the
      latest server descriptor for every router that Tor knows about.


Changes in version 0.1.0.16 - 2006-01-02
  o Crash bugfixes on 0.1.0.x:
    - On Windows, build with a libevent patch from "I-M Weasel" to avoid
      corrupting the heap, losing FDs, or crashing when we need to resize
      the fd_sets. (This affects the Win32 binaries, not Tor's sources.)
    - It turns out sparc64 platforms crash on unaligned memory access
      too -- so detect and avoid this.
    - Handle truncated compressed data correctly (by detecting it and
      giving an error).
    - Fix possible-but-unlikely free(NULL) in control.c.
    - When we were closing connections, there was a rare case that
      stomped on memory, triggering seg faults and asserts.
    - Avoid potential infinite recursion when building a descriptor. (We
      don't know that it ever happened, but better to fix it anyway.)
    - We were neglecting to unlink marked circuits from soon-to-close OR
      connections, which caused some rare scribbling on freed memory.
    - Fix a memory stomping race bug when closing the joining point of two
      rendezvous circuits.
    - Fix an assert in time parsing found by Steven Murdoch.

  o Other bugfixes on 0.1.0.x:
    - When we're doing reachability testing, provide more useful log
      messages so the operator knows what to expect.
    - Do not check whether DirPort is reachable when we are suppressing
      advertising it because of hibernation.
    - When building with -static or on Solaris, we sometimes needed -ldl.
    - When we're deciding whether a stream has enough circuits around
      that can handle it, count the freshly dirty ones and not the ones
      that are so dirty they won't be able to handle it.
    - When we're expiring old circuits, we had a logic error that caused
      us to close new rendezvous circuits rather than old ones.
    - Give a more helpful log message when you try to change ORPort via
      the controller: you should upgrade Tor if you want that to work.
    - We were failing to parse Tor versions that start with "Tor ".
    - Tolerate faulty streams better: when a stream fails for reason
      exitpolicy, stop assuming that the router is lying about his exit
      policy. When a stream fails for reason misc, allow it to retry just
      as if it was resolvefailed. When a stream has failed three times,
      reset its failure count so we can try again and get all three tries.


Changes in version 0.1.1.10-alpha - 2005-12-11
  o Correctness bugfixes on 0.1.0.x:
    - On Windows, build with a libevent patch from "I-M Weasel" to avoid
      corrupting the heap, losing FDs, or crashing when we need to resize
      the fd_sets. (This affects the Win32 binaries, not Tor's sources.)
    - Stop doing the complex voodoo overkill checking for insecure
      Diffie-Hellman keys. Just check if it's in [2,p-2] and be happy.
    - When we were closing connections, there was a rare case that
      stomped on memory, triggering seg faults and asserts.
    - We were neglecting to unlink marked circuits from soon-to-close OR
      connections, which caused some rare scribbling on freed memory.
    - When we're deciding whether a stream has enough circuits around
      that can handle it, count the freshly dirty ones and not the ones
      that are so dirty they won't be able to handle it.
    - Recover better from TCP connections to Tor servers that are
      broken but don't tell you (it happens!); and rotate TLS
      connections once a week.
    - When we're expiring old circuits, we had a logic error that caused
      us to close new rendezvous circuits rather than old ones.
    - Fix a scary-looking but apparently harmless bug where circuits
      would sometimes start out in state CIRCUIT_STATE_OR_WAIT at
      servers, and never switch to state CIRCUIT_STATE_OPEN.
    - When building with -static or on Solaris, we sometimes needed to
      build with -ldl.
    - Give a useful message when people run Tor as the wrong user,
      rather than telling them to start chowning random directories.
    - We were failing to inform the controller about new .onion streams.

  o Security bugfixes on 0.1.0.x:
    - Refuse server descriptors if the fingerprint line doesn't match
      the included identity key. Tor doesn't care, but other apps (and
      humans) might actually be trusting the fingerprint line.
    - We used to kill the circuit when we receive a relay command we
      don't recognize. Now we just drop it.
    - Start obeying our firewall options more rigorously:
      . If we can't get to a dirserver directly, try going via Tor.
      . Don't ever try to connect (as a client) to a place our
        firewall options forbid.
      . If we specify a proxy and also firewall options, obey the
        firewall options even when we're using the proxy: some proxies
        can only proxy to certain destinations.
    - Fix a bug found by Lasse Overlier: when we were making internal
      circuits (intended to be cannibalized later for rendezvous and
      introduction circuits), we were picking them so that they had
      useful exit nodes. There was no need for this, and it actually
      aids some statistical attacks.
    - Start treating internal circuits and exit circuits separately.
      It's important to keep them separate because internal circuits
      have their last hops picked like middle hops, rather than like
      exit hops. So exiting on them will break the user's expectations.

  o Bugfixes on 0.1.1.x:
    - Take out the mis-feature where we tried to detect IP address
      flapping for people with DynDNS, and chose not to upload a new
      server descriptor sometimes.
    - Try to be compatible with OpenSSL 0.9.6 again.
    - Log fix: when the controller is logging about .onion addresses,
      sometimes it didn't include the ".onion" part of the address.
    - Don't try to modify options->DirServers internally -- if the
      user didn't specify any, just add the default ones directly to
      the trusted dirserver list. This fixes a bug where people running
      controllers would use SETCONF on some totally unrelated config
      option, and Tor would start yelling at them about changing their
      DirServer lines.
    - Let the controller's redirectstream command specify a port, in
      case the controller wants to change that too.
    - When we requested a pile of server descriptors, we sometimes
      accidentally launched a duplicate request for the first one.
    - Bugfix for trackhostexits: write down the fingerprint of the
      chosen exit, not its nickname, because the chosen exit might not
      be verified.
    - When parsing foo.exit, if foo is unknown, and we are leaving
      circuits unattached, set the chosen_exit field and leave the
      address empty. This matters because controllers got confused
      otherwise.
    - Directory authorities no longer try to download server
      descriptors that they know they will reject.

  o Features and updates:
    - Replace balanced trees with hash tables: this should make stuff
      significantly faster.
    - Resume using the AES counter-mode implementation that we ship,
      rather than OpenSSL's. Ours is significantly faster.
    - Many other CPU and memory improvements.
    - Add a new config option FastFirstHopPK (on by default) so clients
      do a trivial crypto handshake for their first hop, since TLS has
      already taken care of confidentiality and authentication.
    - Add a new config option TestSocks so people can see if their
      applications are using socks4, socks4a, socks5-with-ip, or
      socks5-with-hostname. This way they don't have to keep mucking
      with tcpdump and wondering if something got cached somewhere.
    - Warn when listening on a public address for socks. I suspect a
      lot of people are setting themselves up as open socks proxies,
      and they have no idea that jerks on the Internet are using them,
      since they simply proxy the traffic into the Tor network.
    - Add "private:*" as an alias in configuration for policies. Now
      you can simplify your exit policy rather than needing to list
      every single internal or nonroutable network space.
    - Add a new controller event type that allows controllers to get
      all server descriptors that were uploaded to a router in its role
      as authoritative dirserver.
    - Start shipping socks-extensions.txt, tor-doc-unix.html,
      tor-doc-server.html, and stylesheet.css in the tarball.
    - Stop shipping tor-doc.html in the tarball.


Changes in version 0.1.1.9-alpha - 2005-11-15
  o Usability improvements:
    - Start calling it FooListenAddress rather than FooBindAddress,
      since few of our users know what it means to bind an address
      or port.
    - Reduce clutter in server logs. We're going to try to make
      them actually usable now. New config option ProtocolWarnings that
      lets you hear about how _other Tors_ are breaking the protocol. Off
      by default.
    - Divide log messages into logging domains. Once we put some sort
      of interface on this, it will let people looking at more verbose
      log levels specify the topics they want to hear more about.
    - Make directory servers return better http 404 error messages
      instead of a generic "Servers unavailable".
    - Check for even more Windows version flags when writing the platform
      string in server descriptors, and note any we don't recognize.
    - Clean up more of the OpenSSL memory when exiting, so we can detect
      memory leaks better.
    - Make directory authorities be non-versioning, non-naming by
      default. Now we can add new directory servers without requiring
      their operators to pay close attention.
    - When logging via syslog, include the pid whenever we provide
      a log entry. Suggested by Todd Fries.

  o Performance improvements:
    - Directory servers now silently throw away new descriptors that
      haven't changed much if the timestamps are similar. We do this to
      tolerate older Tor servers that upload a new descriptor every 15
      minutes. (It seemed like a good idea at the time.)
    - Inline bottleneck smartlist functions; use fast versions by default.
    - Add a "Map from digest to void*" abstraction digestmap_t so we
      can do less hex encoding/decoding. Use it in router_get_by_digest()
      to resolve a performance bottleneck.
    - Allow tor_gzip_uncompress to extract as much as possible from
      truncated compressed data. Try to extract as many
      descriptors as possible from truncated http responses (when
      DIR_PURPOSE_FETCH_ROUTERDESC).
    - Make circ->onionskin a pointer, not a static array. moria2 was using
      125000 circuit_t's after it had been up for a few weeks, which
      translates to 20+ megs of wasted space.
    - The private half of our EDH handshake keys are now chosen out
      of 320 bits, not 1024 bits. (Suggested by Ian Goldberg.)

  o Security improvements:
    - Start making directory caches retain old routerinfos, so soon
      clients can start asking by digest of descriptor rather than by
      fingerprint of server.
    - Add half our entropy from RAND_poll in OpenSSL. This knows how
      to use egd (if present), openbsd weirdness (if present), vms/os2
      weirdness (if we ever port there), and more in the future.

  o Bugfixes on 0.1.0.x:
    - Do round-robin writes of at most 16 kB per write. This might be
      more fair on loaded Tor servers, and it might resolve our Windows
      crash bug. It might also slow things down.
    - Our TLS handshakes were generating a single public/private
      keypair for the TLS context, rather than making a new one for
      each new connections. Oops. (But we were still rotating them
      periodically, so it's not so bad.)
    - When we were cannibalizing a circuit with a particular exit
      node in mind, we weren't checking to see if that exit node was
      already present earlier in the circuit. Oops.
    - When a Tor server's IP changes (e.g. from a dyndns address),
      upload a new descriptor so clients will learn too.
    - Really busy servers were keeping enough circuits open on stable
      connections that they were wrapping around the circuit_id
      space. (It's only two bytes.) This exposed a bug where we would
      feel free to reuse a circuit_id even if it still exists but has
      been marked for close. Try to fix this bug. Some bug remains.
    - If we would close a stream early (e.g. it asks for a .exit that
      we know would refuse it) but the LeaveStreamsUnattached config
      option is set by the controller, then don't close it.

  o Bugfixes on 0.1.1.8-alpha:
    - Fix a big pile of memory leaks, some of them serious.
    - Do not try to download a routerdesc if we would immediately reject
      it as obsolete.
    - Resume inserting a newline between all router descriptors when
      generating (old style) signed directories, since our spec says
      we do.
    - When providing content-type application/octet-stream for
      server descriptors using .z, we were leaving out the
      content-encoding header. Oops. (Everything tolerated this just
      fine, but that doesn't mean we need to be part of the problem.)
    - Fix a potential seg fault in getconf and getinfo using version 1
      of the controller protocol.
    - Avoid crash: do not check whether DirPort is reachable when we
      are suppressing it because of hibernation.
    - Make --hash-password not crash on exit.


Changes in version 0.1.1.8-alpha - 2005-10-07
  o New features (major):
    - Clients don't download or use the directory anymore. Now they
      download and use network-statuses from the trusted dirservers,
      and fetch individual server descriptors as needed from mirrors.
      See dir-spec.txt for all the gory details.
    - Be more conservative about whether to advertise our DirPort.
      The main change is to not advertise if we're running at capacity
      and either a) we could hibernate or b) our capacity is low and
      we're using a default DirPort.
    - Use OpenSSL's AES when OpenSSL has version 0.9.7 or later.

  o New features (minor):
    - Try to be smart about when to retry network-status and
      server-descriptor fetches. Still needs some tuning.
    - Stop parsing, storing, or using running-routers output (but
      mirrors still cache and serve it).
    - Consider a threshold of versioning dirservers (dirservers who have
      an opinion about which Tor versions are still recommended) before
      deciding whether to warn the user that he's obsolete.
    - Dirservers can now reject/invalidate by key and IP, with the
      config options "AuthDirInvalid" and "AuthDirReject". This is
      useful since currently we automatically list servers as running
      and usable even if we know they're jerks.
    - Provide dire warnings to any users who set DirServer; move it out
      of torrc.sample and into torrc.complete.
    - Add MyFamily to torrc.sample in the server section.
    - Add nicknames to the DirServer line, so we can refer to them
      without requiring all our users to memorize their IP addresses.
    - When we get an EOF or a timeout on a directory connection, note
      how many bytes of serverdesc we are dropping. This will help
      us determine whether it is smart to parse incomplete serverdesc
      responses.
    - Add a new function to "change pseudonyms" -- that is, to stop
      using any currently-dirty circuits for new streams, so we don't
      link new actions to old actions. Currently it's only called on
      HUP (or SIGNAL RELOAD).
    - On sighup, if UseHelperNodes changed to 1, use new circuits.
    - Start using RAND_bytes rather than RAND_pseudo_bytes from
      OpenSSL. Also, reseed our entropy every hour, not just at
      startup. And entropy in 512-bit chunks, not 160-bit chunks.

  o Fixes on 0.1.1.7-alpha:
    - Nobody ever implemented EVENT_ADDRMAP for control protocol
      version 0, so don't let version 0 controllers ask for it.
    - If you requested something with too many newlines via the
      v1 controller protocol, you could crash tor.
    - Fix a number of memory leaks, including some pretty serious ones.
    - Re-enable DirPort testing again, so Tor servers will be willing
      to advertise their DirPort if it's reachable.
    - On TLS handshake, only check the other router's nickname against
      its expected nickname if is_named is set.

  o Fixes forward-ported from 0.1.0.15:
    - Don't crash when we don't have any spare file descriptors and we
      try to spawn a dns or cpu worker.
    - Make the numbers in read-history and write-history into uint64s,
      so they don't overflow and publish negatives in the descriptor.

  o Fixes on 0.1.0.x:
    - For the OS X package's modified privoxy config file, comment
      out the "logfile" line so we don't log everything passed
      through privoxy.
    - We were whining about using socks4 or socks5-with-local-lookup
      even when it's an IP in the "virtual" range we designed exactly
      for this case.
    - We were leaking some memory every time the client changes IPs.
    - Never call free() on tor_malloc()d memory. This will help us
      use dmalloc to detect memory leaks.
    - Check for named servers when looking them up by nickname;
      warn when we'recalling a non-named server by its nickname;
      don't warn twice about the same name.
    - Try to list MyFamily elements by key, not by nickname, and warn
      if we've not heard of the server.
    - Make windows platform detection (uname equivalent) smarter.
    - It turns out sparc64 doesn't like unaligned access either.


Changes in version 0.1.0.15 - 2005-09-23
  o Bugfixes on 0.1.0.x:
    - Reject ports 465 and 587 (spam targets) in default exit policy.
    - Don't crash when we don't have any spare file descriptors and we
      try to spawn a dns or cpu worker.
    - Get rid of IgnoreVersion undocumented config option, and make us
      only warn, never exit, when we're running an obsolete version.
    - Don't try to print a null string when your server finds itself to
      be unreachable and the Address config option is empty.
    - Make the numbers in read-history and write-history into uint64s,
      so they don't overflow and publish negatives in the descriptor.
    - Fix a minor memory leak in smartlist_string_remove().
    - We were only allowing ourselves to upload a server descriptor at
      most every 20 minutes, even if it changed earlier than that.
    - Clean up log entries that pointed to old URLs.


Changes in version 0.1.1.7-alpha - 2005-09-14
  o Fixes on 0.1.1.6-alpha:
    - Exit servers were crashing when people asked them to make a
      connection to an address not in their exit policy.
    - Looking up a non-existent stream for a v1 control connection would
      cause a segfault.
    - Fix a seg fault if we ask a dirserver for a descriptor by
      fingerprint but he doesn't know about him.
    - SETCONF was appending items to linelists, not clearing them.
    - SETCONF SocksBindAddress killed Tor if it fails to bind. Now back
      out and refuse the setconf if it would fail.
    - Downgrade the dirserver log messages when whining about
      unreachability.

  o New features:
    - Add Peter Palfrader's check-tor script to tor/contrib/
      It lets you easily check whether a given server (referenced by
      nickname) is reachable by you.
    - Numerous changes to move towards client-side v2 directories. Not
      enabled yet.

  o Fixes on 0.1.0.x:
    - If the user gave tor an odd number of command-line arguments,
      we were silently ignoring the last one. Now we complain and fail.
      [This wins the oldest-bug prize -- this bug has been present since
       November 2002, as released in Tor 0.0.0.]
    - Do not use unaligned memory access on alpha, mips, or mipsel.
      It *works*, but is very slow, so we treat them as if it doesn't.
    - Retry directory requests if we fail to get an answer we like
      from a given dirserver (we were retrying before, but only if
      we fail to connect).
    - When writing the RecommendedVersions line, sort them first.
    - When the client asked for a rendezvous port that the hidden
      service didn't want to provide, we were sending an IP address
      back along with the end cell. Fortunately, it was zero. But stop
      that anyway.
    - Correct "your server is reachable" log entries to indicate that
      it was self-testing that told us so.


Changes in version 0.1.1.6-alpha - 2005-09-09
  o Fixes on 0.1.1.5-alpha:
    - We broke fascistfirewall in 0.1.1.5-alpha. Oops.
    - Fix segfault in unit tests in 0.1.1.5-alpha. Oops.
    - Fix bug with tor_memmem finding a match at the end of the string.
    - Make unit tests run without segfaulting.
    - Resolve some solaris x86 compile warnings.
    - Handle duplicate lines in approved-routers files without warning.
    - Fix bug where as soon as a server refused any requests due to his
      exit policy (e.g. when we ask for localhost and he tells us that's
      127.0.0.1 and he won't do it), we decided he wasn't obeying his
      exit policy using him for any exits.
    - Only do openssl hardware accelerator stuff if openssl version is
      at least 0.9.7.

  o New controller features/fixes:
    - Add a "RESETCONF" command so you can set config options like
      AllowUnverifiedNodes and LongLivedPorts to "". Also, if you give
      a config option in the torrc with no value, then it clears it
      entirely (rather than setting it to its default).
    - Add a "GETINFO config-file" to tell us where torrc is.
    - Avoid sending blank lines when GETINFO replies should be empty.
    - Add a QUIT command for the controller (for using it manually).
    - Fix a bug in SAVECONF that was adding default dirservers and
      other redundant entries to the torrc file.

  o Start on the new directory design:
    - Generate, publish, cache, serve new network-status format.
    - Publish individual descriptors (by fingerprint, by "all", and by
      "tell me yours").
    - Publish client and server recommended versions separately.
    - Allow tor_gzip_uncompress() to handle multiple concatenated
      compressed strings. Serve compressed groups of router
      descriptors. The compression logic here could be more
      memory-efficient.
    - Distinguish v1 authorities (all currently trusted directories)
      from v2 authorities (all trusted directories).
    - Change DirServers config line to note which dirs are v1 authorities.
    - Add configuration option "V1AuthoritativeDirectory 1" which
      moria1, moria2, and tor26 should set.
    - Remove option when getting directory cache to see whether they
      support running-routers; they all do now. Replace it with one
      to see whether caches support v2 stuff.

  o New features:
    - Dirservers now do their own external reachability testing of each
      Tor server, and only list them as running if they've been found to
      be reachable. We also send back warnings to the server's logs if
      it uploads a descriptor that we already believe is unreachable.
    - Implement exit enclaves: if we know an IP address for the
      destination, and there's a running Tor server at that address
      which allows exit to the destination, then extend the circuit to
      that exit first. This provides end-to-end encryption and end-to-end
      authentication. Also, if the user wants a .exit address or enclave,
      use 4 hops rather than 3, and cannibalize a general circ for it
      if you can.
    - Permit transitioning from ORPort=0 to ORPort!=0, and back, from the
      controller. Also, rotate dns and cpu workers if the controller
      changes options that will affect them; and initialize the dns
      worker cache tree whether or not we start out as a server.
    - Only upload a new server descriptor when options change, 18
      hours have passed, uptime is reset, or bandwidth changes a lot.
    - Check [X-]Forwarded-For headers in HTTP requests when generating
      log messages. This lets people run dirservers (and caches) behind
      Apache but still know which IP addresses are causing warnings.

  o Config option changes:
    - Replace (Fascist)Firewall* config options with a new
      ReachableAddresses option that understands address policies.
      For example, "ReachableAddresses *:80,*:443"
    - Get rid of IgnoreVersion undocumented config option, and make us
      only warn, never exit, when we're running an obsolete version.
    - Make MonthlyAccountingStart config option truly obsolete now.

  o Fixes on 0.1.0.x:
    - Reject ports 465 and 587 in the default exit policy, since
      people have started using them for spam too.
    - It turns out we couldn't bootstrap a network since we added
      reachability detection in 0.1.0.1-rc. Good thing the Tor network
      has never gone down. Add an AssumeReachable config option to let
      servers and dirservers bootstrap. When we're trying to build a
      high-uptime or high-bandwidth circuit but there aren't enough
      suitable servers, try being less picky rather than simply failing.
    - Our logic to decide if the OR we connected to was the right guy
      was brittle and maybe open to a mitm for unverified routers.
    - We weren't cannibalizing circuits correctly for
      CIRCUIT_PURPOSE_C_ESTABLISH_REND and
      CIRCUIT_PURPOSE_S_ESTABLISH_INTRO, so we were being forced to
      build those from scratch. This should make hidden services faster.
    - Predict required circuits better, with an eye toward making hidden
      services faster on the service end.
    - Retry streams if the exit node sends back a 'misc' failure. This
      should result in fewer random failures. Also, after failing
      from resolve failed or misc, reset the num failures, so we give
      it a fair shake next time we try.
    - Clean up the rendezvous warn log msgs, and downgrade some to info.
    - Reduce severity on logs about dns worker spawning and culling.
    - When we're shutting down and we do something like try to post a
      server descriptor or rendezvous descriptor, don't complain that
      we seem to be unreachable. Of course we are, we're shutting down.
    - Add TTLs to RESOLVED, CONNECTED, and END_REASON_EXITPOLICY cells.
      We don't use them yet, but maybe one day our DNS resolver will be
      able to discover them.
    - Make ContactInfo mandatory for authoritative directory servers.
    - Require server descriptors to list IPv4 addresses -- hostnames
      are no longer allowed. This also fixes some potential security
      problems with people providing hostnames as their address and then
      preferentially resolving them to partition users.
    - Change log line for unreachability to explicitly suggest /etc/hosts
      as the culprit. Also make it clearer what IP address and ports we're
      testing for reachability.
    - Put quotes around user-supplied strings when logging so users are
      more likely to realize if they add bad characters (like quotes)
      to the torrc.
    - Let auth dir servers start without specifying an Address config
      option.
    - Make unit tests (and other invocations that aren't the real Tor)
      run without launching listeners, creating subdirectories, and so on.


Changes in version 0.1.1.5-alpha - 2005-08-08
  o Bugfixes included in 0.1.0.14.

  o Bugfixes on 0.1.0.x:
    - If you write "HiddenServicePort 6667 127.0.0.1 6668" in your
      torrc rather than "HiddenServicePort 6667 127.0.0.1:6668",
      it would silently using ignore the 6668.


Changes in version 0.1.0.14 - 2005-08-08
  o Bugfixes on 0.1.0.x:
      - Fix the other half of the bug with crypto handshakes
        (CVE-2005-2643).
      - Fix an assert trigger if you send a 'signal term' via the
        controller when it's listening for 'event info' messages.


Changes in version 0.1.1.4-alpha - 2005-08-04
  o Bugfixes included in 0.1.0.13.

  o Features:
    - Improve tor_gettimeofday() granularity on windows.
    - Make clients regenerate their keys when their IP address changes.
    - Implement some more GETINFO goodness: expose helper nodes, config
      options, getinfo keys.


Changes in version 0.1.0.13 - 2005-08-04
  o Bugfixes on 0.1.0.x:
    - Fix a critical bug in the security of our crypto handshakes.
    - Fix a size_t underflow in smartlist_join_strings2() that made
      it do bad things when you hand it an empty smartlist.
    - Fix Windows installer to ship Tor license (thanks to Aphex for
      pointing out this oversight) and put a link to the doc directory
      in the start menu.
    - Explicitly set no-unaligned-access for sparc: it turns out the
      new gcc's let you compile broken code, but that doesn't make it
      not-broken.


Changes in version 0.1.1.3-alpha - 2005-07-23
  o Bugfixes on 0.1.1.2-alpha:
    - Fix a bug in handling the controller's "post descriptor"
      function.
    - Fix several bugs in handling the controller's "extend circuit"
      function.
    - Fix a bug in handling the controller's "stream status" event.
    - Fix an assert failure if we have a controller listening for
      circuit events and we go offline.
    - Re-allow hidden service descriptors to publish 0 intro points.
    - Fix a crash when generating your hidden service descriptor if
      you don't have enough intro points already.

  o New features on 0.1.1.2-alpha:
    - New controller function "getinfo accounting", to ask how
      many bytes we've used in this time period.
    - Experimental support for helper nodes: a lot of the risk from
      a small static adversary comes because users pick new random
      nodes every time they rebuild a circuit. Now users will try to
      stick to the same small set of entry nodes if they can. Not
      enabled by default yet.

  o Bugfixes on 0.1.0.12:
    - If you're an auth dir server, always publish your dirport,
      even if you haven't yet found yourself to be reachable.
    - Fix a size_t underflow in smartlist_join_strings2() that made
      it do bad things when you hand it an empty smartlist.


Changes in version 0.1.0.12 - 2005-07-18
  o New directory servers:
      - tor26 has changed IP address.

  o Bugfixes on 0.1.0.x:
    - Fix a possible double-free in tor_gzip_uncompress().
    - When --disable-threads is set, do not search for or link against
      pthreads libraries.
    - Don't trigger an assert if an authoritative directory server
      claims its dirport is 0.
    - Fix bug with removing Tor as an NT service: some people were
      getting "The service did not return an error." Thanks to Matt
      Edman for the fix.


Changes in version 0.1.1.2-alpha - 2005-07-15
  o New directory servers:
    - tor26 has changed IP address.

  o Bugfixes on 0.1.0.x, crashes/leaks:
    - Port the servers-not-obeying-their-exit-policies fix from
      0.1.0.11.
    - Fix an fd leak in start_daemon().
    - On Windows, you can't always reopen a port right after you've
      closed it. So change retry_listeners() to only close and re-open
      ports that have changed.
    - Fix a possible double-free in tor_gzip_uncompress().

  o Bugfixes on 0.1.0.x, usability:
    - When tor_socketpair() fails in Windows, give a reasonable
      Windows-style errno back.
    - Let people type "tor --install" as well as "tor -install" when
      they
      want to make it an NT service.
    - NT service patch from Matt Edman to improve error messages.
    - When the controller asks for a config option with an abbreviated
      name, give the full name in our response.
    - Correct the man page entry on TrackHostExitsExpire.
    - Looks like we were never delivering deflated (i.e. compressed)
      running-routers lists, even when asked. Oops.
    - When --disable-threads is set, do not search for or link against
      pthreads libraries.

  o Bugfixes on 0.1.1.x:
    - Fix a seg fault with autodetecting which controller version is
      being used.

  o Features:
    - New hidden service descriptor format: put a version in it, and
      let people specify introduction/rendezvous points that aren't
      in "the directory" (which is subjective anyway).
    - Allow the DEBUG controller event to work again. Mark certain log
      entries as "don't tell this to controllers", so we avoid cycles.


Changes in version 0.1.0.11 - 2005-06-30
  o Bugfixes on 0.1.0.x:
    - Fix major security bug: servers were disregarding their
      exit policies if clients behaved unexpectedly.
    - Make OS X init script check for missing argument, so we don't
      confuse users who invoke it incorrectly.
    - Fix a seg fault in "tor --hash-password foo".
    - The MAPADDRESS control command was broken.


Changes in version 0.1.1.1-alpha - 2005-06-29
  o Bugfixes:
    - Make OS X init script check for missing argument, so we don't
      confuse users who invoke it incorrectly.
    - Fix a seg fault in "tor --hash-password foo".
    - Fix a possible way to DoS dirservers.
    - When we complain that your exit policy implicitly allows local or
      private address spaces, name them explicitly so operators can
      fix it.
    - Make the log message less scary when all the dirservers are
      temporarily unreachable.
    - We were printing the number of idle dns workers incorrectly when
      culling them.

  o Features:
    - Revised controller protocol (version 1) that uses ascii rather
      than binary. Add supporting libraries in python and java so you
      can use the controller from your applications without caring how
      our protocol works.
    - Spiffy new support for crypto hardware accelerators. Can somebody
      test this?


Changes in version 0.0.9.10 - 2005-06-16
  o Bugfixes on 0.0.9.x (backported from 0.1.0.10):
    - Refuse relay cells that claim to have a length larger than the
      maximum allowed. This prevents a potential attack that could read
      arbitrary memory (e.g. keys) from an exit server's process
      (CVE-2005-2050).


Changes in version 0.1.0.10 - 2005-06-14
  o Allow a few EINVALs from libevent before dying. Warn on kqueue with
    libevent before 1.1a.


Changes in version 0.1.0.9-rc - 2005-06-09
  o Bugfixes:
    - Reset buf->highwater every time buf_shrink() is called, not just on
      a successful shrink. This was causing significant memory bloat.
    - Fix buffer overflow when checking hashed passwords.
    - Security fix: if seeding the RNG on Win32 fails, quit.
    - Allow seeding the RNG on Win32 even when you're not running as
      Administrator.
    - Disable threading on Solaris too. Something is wonky with it,
      cpuworkers, and reentrant libs.
    - Reenable the part of the code that tries to flush as soon as an
      OR outbuf has a full TLS record available. Perhaps this will make
      OR outbufs not grow as huge except in rare cases, thus saving lots
      of CPU time plus memory.
    - Reject malformed .onion addresses rather then passing them on as
      normal web requests.
    - Adapt patch from Adam Langley: fix possible memory leak in
      tor_lookup_hostname().
    - Initialize libevent later in the startup process, so the logs are
      already established by the time we start logging libevent warns.
    - Use correct errno on win32 if libevent fails.
    - Check and warn about known-bad/slow libevent versions.
    - Pay more attention to the ClientOnly config option.
    - Have torctl.in/tor.sh.in check for location of su binary (needed
      on FreeBSD)
    - Correct/add man page entries for LongLivedPorts, ExitPolicy,
      KeepalivePeriod, ClientOnly, NoPublish, HttpProxy, HttpsProxy,
      HttpProxyAuthenticator
    - Stop warning about sigpipes in the logs. We're going to
      pretend that getting these occassionally is normal and fine.
    - Resolve OS X installer bugs: stop claiming to be 0.0.9.2 in
      certain
      installer screens; and don't put stuff into StartupItems unless
      the user asks you to.
    - Require servers that use the default dirservers to have public IP
      addresses. We have too many servers that are configured with private
      IPs and their admins never notice the log entries complaining that
      their descriptors are being rejected.
    - Add OSX uninstall instructions. An actual uninstall script will
      come later.


Changes in version 0.1.0.8-rc - 2005-05-23
  o Bugfixes:
    - It turns out that kqueue on OS X 10.3.9 was causing kernel
      panics. Disable kqueue on all OS X Tors.
    - Fix RPM: remove duplicate line accidentally added to the rpm
      spec file.
    - Disable threads on openbsd too, since its gethostaddr is not
      reentrant either.
    - Tolerate libevent 0.8 since it still works, even though it's
      ancient.
    - Enable building on Red Hat 9.0 again.
    - Allow the middle hop of the testing circuit to be running any
      version, now that most of them have the bugfix to let them connect
      to unknown servers. This will allow reachability testing to work
      even when 0.0.9.7-0.0.9.9 become obsolete.
    - Handle relay cells with rh.length too large. This prevents
      a potential attack that could read arbitrary memory (maybe even
      keys) from the exit server's process.
    - We screwed up the dirport reachability testing when we don't yet
      have a cached version of the directory. Hopefully now fixed.
    - Clean up router_load_single_router() (used by the controller),
      so it doesn't seg fault on error.
    - Fix a minor memory leak when somebody establishes an introduction
      point at your Tor server.
    - If a socks connection ends because read fails, don't warn that
      you're not sending a socks reply back.

  o Features:
    - Add HttpProxyAuthenticator config option too, that works like
      the HttpsProxyAuthenticator config option.
    - Encode hashed controller passwords in hex instead of base64,
      to make it easier to write controllers.


Changes in version 0.1.0.7-rc - 2005-05-17
  o Bugfixes:
    - Fix a bug in the OS X package installer that prevented it from
      installing on Tiger.
    - Fix a script bug in the OS X package installer that made it
      complain during installation.
    - Find libevent even if it's hiding in /usr/local/ and your
      CFLAGS and LDFLAGS don't tell you to look there.
    - Be able to link with libevent as a shared library (the default
      after 1.0d), even if it's hiding in /usr/local/lib and even
      if you haven't added /usr/local/lib to your /etc/ld.so.conf,
      assuming you're running gcc. Otherwise fail and give a useful
      error message.
    - Fix a bug in the RPM packager: set home directory for _tor to
      something more reasonable when first installing.
    - Free a minor amount of memory that is still reachable on exit.


Changes in version 0.1.0.6-rc - 2005-05-14
  o Bugfixes:
    - Implement --disable-threads configure option. Disable threads on
      netbsd by default, because it appears to have no reentrant resolver
      functions.
    - Apple's OS X 10.4.0 ships with a broken kqueue. The new libevent
      release (1.1) detects and disables kqueue if it's broken.
    - Append default exit policy before checking for implicit internal
      addresses. Now we don't log a bunch of complaints on startup
      when using the default exit policy.
    - Some people were putting "Address  " in their torrc, and they had
      a buggy resolver that resolved " " to 0.0.0.0. Oops.
    - If DataDir is ~/.tor, and that expands to /.tor, then default to
      LOCALSTATEDIR/tor instead.
    - Fix fragmented-message bug in TorControl.py.
    - Resolve a minor bug which would prevent unreachable dirports
      from getting suppressed in the published descriptor.
    - When the controller gave us a new descriptor, we weren't resolving
      it immediately, so Tor would think its address was 0.0.0.0 until
      we fetched a new directory.
    - Fix an uppercase/lowercase case error in suppressing a bogus
      libevent warning on some Linuxes.

  o Features:
    - Begin scrubbing sensitive strings from logs by default. Turn off
      the config option SafeLogging if you need to do debugging.
    - Switch to a new buffer management algorithm, which tries to avoid
      reallocing and copying quite as much. In first tests it looks like
      it uses *more* memory on average, but less cpu.
    - First cut at support for "create-fast" cells. Clients can use
      these when extending to their first hop, since the TLS already
      provides forward secrecy and authentication. Not enabled on
      clients yet.
    - When dirservers refuse a router descriptor, we now log its
      contactinfo, platform, and the poster's IP address.
    - Call tor_free_all instead of connections_free_all after forking, to
      save memory on systems that need to fork.
    - Whine at you if you're a server and you don't set your contactinfo.
    - Implement --verify-config command-line option to check if your torrc
      is valid without actually launching Tor.
    - Rewrite address "serifos.exit" to "localhost.serifos.exit"
      rather than just rejecting it.


Changes in version 0.1.0.5-rc - 2005-04-27
  o Bugfixes:
    - Stop trying to print a null pointer if an OR conn fails because
      we didn't like its cert.
  o Features:
    - Switch our internal buffers implementation to use a ring buffer,
      to hopefully improve performance for fast servers a lot.
    - Add HttpsProxyAuthenticator support (basic auth only), based
      on patch from Adam Langley.
    - Bump the default BandwidthRate from 1 MB to 2 MB, to accommodate
      the fast servers that have been joining lately.
    - Give hidden service accesses extra time on the first attempt,
      since 60 seconds is often only barely enough. This might improve
      robustness more.
    - Improve performance for dirservers: stop re-parsing the whole
      directory every time you regenerate it.
    - Add more debugging info to help us find the weird dns freebsd
      pthreads bug; cleaner debug messages to help track future issues.


Changes in version 0.0.9.9 - 2005-04-23
  o Bugfixes on 0.0.9.x:
    - If unofficial Tor clients connect and send weird TLS certs, our
      Tor server triggers an assert. This release contains a minimal
      backport from the broader fix that we put into 0.1.0.4-rc.


Changes in version 0.1.0.4-rc - 2005-04-23
  o Bugfixes:
    - If unofficial Tor clients connect and send weird TLS certs, our
      Tor server triggers an assert. Stop asserting, and start handling
      TLS errors better in other situations too.
    - When the controller asks us to tell it about all the debug-level
      logs, it turns out we were generating debug-level logs while
      telling it about them, which turns into a bad loop. Now keep
      track of whether you're sending a debug log to the controller,
      and don't log when you are.
    - Fix the "postdescriptor" feature of the controller interface: on
      non-complete success, only say "done" once.
  o Features:
    - Clients are now willing to load balance over up to 2mB, not 1mB,
      of advertised bandwidth capacity.
    - Add a NoPublish config option, so you can be a server (e.g. for
      testing running Tor servers in other Tor networks) without
      publishing your descriptor to the primary dirservers.


Changes in version 0.1.0.3-rc - 2005-04-08
  o Improvements on 0.1.0.2-rc:
    - Client now retries when streams end early for 'hibernating' or
      'resource limit' reasons, rather than failing them.
    - More automated handling for dirserver operators:
      - Automatically approve nodes running 0.1.0.2-rc or later,
        now that the the reachability detection stuff is working.
      - Now we allow two unverified servers with the same nickname
        but different keys. But if a nickname is verified, only that
        nickname+key are allowed.
      - If you're an authdirserver connecting to an address:port,
        and it's not the OR you were expecting, forget about that
        descriptor. If he *was* the one you were expecting, then forget
        about all other descriptors for that address:port.
      - Allow servers to publish descriptors from 12 hours in the future.
        Corollary: only whine about clock skew from the dirserver if
        he's a trusted dirserver (since now even verified servers could
        have quite wrong clocks).
    - Adjust maximum skew and age for rendezvous descriptors: let skew
      be 48 hours rather than 90 minutes.
    - Efficiency improvements:
      - Keep a big splay tree of (circid,orconn)->circuit mappings to make
        it much faster to look up a circuit for each relay cell.
      - Remove most calls to assert_all_pending_dns_resolves_ok(),
        since they're eating our cpu on exit nodes.
      - Stop wasting time doing a case insensitive comparison for every
        dns name every time we do any lookup. Canonicalize the names to
        lowercase and be done with it.
    - Start sending 'truncated' cells back rather than destroy cells,
      if the circuit closes in front of you. This means we won't have
      to abandon partially built circuits.
    - Only warn once per nickname from add_nickname_list_to_smartlist
      per failure, so an entrynode or exitnode choice that's down won't
      yell so much.
    - Put a note in the torrc about abuse potential with the default
      exit policy.
    - Revise control spec and implementation to allow all log messages to
      be sent to controller with their severities intact (suggested by
      Matt Edman). Update TorControl to handle new log event types.
    - Provide better explanation messages when controller's POSTDESCRIPTOR
      fails.
    - Stop putting nodename in the Platform string in server descriptors.
      It doesn't actually help, and it is confusing/upsetting some people.

  o Bugfixes on 0.1.0.2-rc:
    - We were printing the host mask wrong in exit policies in server
      descriptors. This isn't a critical bug though, since we were still
      obeying the exit policy internally.
    - Fix Tor when compiled with libevent but without pthreads: move
      connection_unregister() from _connection_free() to
      connection_free().
    - Fix an assert trigger (already fixed in 0.0.9.x): when we have
      the rare mysterious case of accepting a conn on 0.0.0.0:0, then
      when we look through the connection array, we'll find any of the
      cpu/dnsworkers. This is no good.

  o Bugfixes on 0.0.9.8:
    - Fix possible bug on threading platforms (e.g. win32) which was
      leaking a file descriptor whenever a cpuworker or dnsworker died.
    - When using preferred entry or exit nodes, ignore whether the
      circuit wants uptime or capacity. They asked for the nodes, they
      get the nodes.
    - chdir() to your datadirectory at the *end* of the daemonize process,
      not the beginning. This was a problem because the first time you
      run tor, if your datadir isn't there, and you have runasdaemon set
      to 1, it will try to chdir to it before it tries to create it. Oops.
    - Handle changed router status correctly when dirserver reloads
      fingerprint file. We used to be dropping all unverified descriptors
      right then. The bug was hidden because we would immediately
      fetch a directory from another dirserver, which would include the
      descriptors we just dropped.
    - When we're connecting to an OR and he's got a different nickname/key
      than we were expecting, only complain loudly if we're an OP or a
      dirserver. Complaining loudly to the OR admins just confuses them.
    - Tie MAX_DIR_SIZE to MAX_BUF_SIZE, so now directory sizes won't get
      artificially capped at 500kB.


Changes in version 0.0.9.8 - 2005-04-07
  o Bugfixes on 0.0.9.x:
    - We have a bug that I haven't found yet. Sometimes, very rarely,
      cpuworkers get stuck in the 'busy' state, even though the cpuworker
      thinks of itself as idle. This meant that no new circuits ever got
      established. Here's a workaround to kill any cpuworker that's been
      busy for more than 100 seconds.


Changes in version 0.1.0.2-rc - 2005-04-01
  o Bugfixes on 0.1.0.1-rc:
    - Fixes on reachability detection:
      - Don't check for reachability while hibernating.
      - If ORPort is reachable but DirPort isn't, still publish the
        descriptor, but zero out DirPort until it's found reachable.
      - When building testing circs for ORPort testing, use only
        high-bandwidth nodes, so fewer circuits fail.
      - Complain about unreachable ORPort separately from unreachable
        DirPort, so the user knows what's going on.
      - Make sure we only conclude ORPort reachability if we didn't
        initiate the conn. Otherwise we could falsely conclude that
        we're reachable just because we connected to the guy earlier
        and he used that same pipe to extend to us.
      - Authdirservers shouldn't do ORPort reachability detection,
        since they're in clique mode, so it will be rare to find a
        server not already connected to them.
      - When building testing circuits, always pick middle hops running
        Tor 0.0.9.7, so we avoid the "can't extend to unknown routers"
        bug. (This is a kludge; it will go away when 0.0.9.x becomes
        obsolete.)
      - When we decide we're reachable, actually publish our descriptor
        right then.
    - Fix bug in redirectstream in the controller.
    - Fix the state descriptor strings so logs don't claim edge streams
      are in a different state than they actually are.
    - Use recent libevent features when possible (this only really affects
      win32 and osx right now, because the new libevent with these
      features hasn't been released yet). Add code to suppress spurious
      libevent log msgs.
    - Prevent possible segfault in connection_close_unattached_ap().
    - Fix newlines on torrc in win32.
    - Improve error msgs when tor-resolve fails.

  o Improvements on 0.0.9.x:
    - New experimental script tor/contrib/ExerciseServer.py (needs more
      work) that uses the controller interface to build circuits and
      fetch pages over them. This will help us bootstrap servers that
      have lots of capacity but haven't noticed it yet.
    - New experimental script tor/contrib/PathDemo.py (needs more work)
      that uses the controller interface to let you choose whole paths
      via addresses like
      "<hostname>.<path,separated by dots>.<length of path>.path"
    - When we've connected to an OR and handshaked but didn't like
      the result, we were closing the conn without sending destroy
      cells back for pending circuits. Now send those destroys.


Changes in version 0.0.9.7 - 2005-04-01
  o Bugfixes on 0.0.9.x:
    - Fix another race crash bug (thanks to Glenn Fink for reporting).
    - Compare identity to identity, not to nickname, when extending to
      a router not already in the directory. This was preventing us from
      extending to unknown routers. Oops.
    - Make sure to create OS X Tor user in <500 range, so we aren't
      creating actual system users.
    - Note where connection-that-hasn't-sent-end was marked, and fix
      a few really loud instances of this harmless bug (it's fixed more
      in 0.1.0.x).


Changes in version 0.1.0.1-rc - 2005-03-28
  o New features:
    - Add reachability testing. Your Tor server will automatically try
      to see if its ORPort and DirPort are reachable from the outside,
      and it won't upload its descriptor until it decides they are.
    - Handle unavailable hidden services better. Handle slow or busy
      hidden services better.
    - Add support for CONNECTing through https proxies, with "HttpsProxy"
      config option.
    - New exit policy: accept most low-numbered ports, rather than
      rejecting most low-numbered ports.
    - More Tor controller support (still experimental). See
      http://tor.eff.org/doc/control-spec.txt for all the new features,
      including signals to emulate unix signals from any platform;
      redirectstream; extendcircuit; mapaddress; getinfo; postdescriptor;
      closestream; closecircuit; etc.
    - Make nt services work and start on startup on win32 (based on
      patch by Matt Edman).
    - Add a new AddressMap config directive to rewrite incoming socks
      addresses. This lets you, for example, declare an implicit
      required exit node for certain sites.
    - Add a new TrackHostExits config directive to trigger addressmaps
      for certain incoming socks addresses -- for sites that break when
      your exit keeps changing (based on patch by Mike Perry).
    - Redo the client-side dns cache so it's just an addressmap too.
    - Notice when our IP changes, and reset stats/uptime/reachability.
    - When an application is using socks5, give him the whole variety of
      potential socks5 responses (connect refused, host unreachable, etc),
      rather than just "success" or "failure".
    - A more sane version numbering system. See
      http://tor.eff.org/cvs/tor/doc/version-spec.txt for details.
    - New contributed script "exitlist": a simple python script to
      parse directories and find Tor nodes that exit to listed
      addresses/ports.
    - New contributed script "privoxy-tor-toggle" to toggle whether
      Privoxy uses Tor. Seems to be configured for Debian by default.
    - Report HTTP reasons to client when getting a response from directory
      servers -- so you can actually know what went wrong.
    - New config option MaxAdvertisedBandwidth which lets you advertise
      a low bandwidthrate (to not attract as many circuits) while still
      allowing a higher bandwidthrate in reality.

  o Robustness/stability fixes:
    - Make Tor use Niels Provos's libevent instead of its current
      poll-but-sometimes-select mess. This will let us use faster async
      cores (like epoll, kpoll, and /dev/poll), and hopefully work better
      on Windows too.
    - pthread support now too. This was forced because when we forked,
      we ended up wasting a lot of duplicate ram over time. Also switch
      to foo_r versions of some library calls to allow reentry and
      threadsafeness.
    - Better handling for heterogeneous / unreliable nodes:
      - Annotate circuits w/ whether they aim to contain high uptime nodes
        and/or high capacity nodes. When building circuits, choose
        appropriate nodes.
      - This means that every single node in an intro rend circuit,
        not just the last one, will have a minimum uptime.
      - New config option LongLivedPorts to indicate application streams
        that will want high uptime circuits.
      - Servers reset uptime when a dir fetch entirely fails. This
        hopefully reflects stability of the server's network connectivity.
      - If somebody starts his tor server in Jan 2004 and then fixes his
        clock, don't make his published uptime be a year.
      - Reset published uptime when you wake up from hibernation.
    - Introduce a notion of 'internal' circs, which are chosen without
      regard to the exit policy of the last hop. Intro and rendezvous
      circs must be internal circs, to avoid leaking information. Resolve
      and connect streams can use internal circs if they want.
    - New circuit pooling algorithm: make sure to have enough circs around
      to satisfy any predicted ports, and also make sure to have 2 internal
      circs around if we've required internal circs lately (and with high
      uptime if we've seen that lately too).
    - Split NewCircuitPeriod option into NewCircuitPeriod (30 secs),
      which describes how often we retry making new circuits if current
      ones are dirty, and MaxCircuitDirtiness (10 mins), which describes
      how long we're willing to make use of an already-dirty circuit.
    - Cannibalize GENERAL circs to be C_REND, C_INTRO, S_INTRO, and S_REND
      circ as necessary, if there are any completed ones lying around
      when we try to launch one.
    - Make hidden services try to establish a rendezvous for 30 seconds,
      rather than for n (where n=3) attempts to build a circuit.
    - Change SHUTDOWN_WAIT_LENGTH from a fixed 30 secs to a config option
      "ShutdownWaitLength".
    - Try to be more zealous about calling connection_edge_end when
      things go bad with edge conns in connection.c.
    - Revise tor-spec to add more/better stream end reasons.
    - Revise all calls to connection_edge_end to avoid sending "misc",
      and to take errno into account where possible.

  o Bug fixes:
    - Fix a race condition that can trigger an assert, when we have a
      pending create cell and an OR connection fails right then.
    - Fix several double-mark-for-close bugs, e.g. where we were finding
      a conn for a cell even if that conn is already marked for close.
    - Make sequence of log messages when starting on win32 with no config
      file more reasonable.
    - When choosing an exit node for a new non-internal circ, don't take
      into account whether it'll be useful for any pending x.onion
      addresses -- it won't.
    - Turn addr_policy_compare from a tristate to a quadstate; this should
      help address our "Ah, you allow 1.2.3.4:80. You are a good choice
      for google.com" problem.
    - Make "platform" string in descriptor more accurate for Win32 servers,
      so it's not just "unknown platform".
    - Fix an edge case in parsing config options (thanks weasel).
      If they say "--" on the commandline, it's not an option.
    - Reject odd-looking addresses at the client (e.g. addresses that
      contain a colon), rather than having the server drop them because
      they're malformed.
    - tor-resolve requests were ignoring .exit if there was a working circuit
      they could use instead.
    - REUSEADDR on normal platforms means you can rebind to the port
      right after somebody else has let it go. But REUSEADDR on win32
      means to let you bind to the port _even when somebody else
      already has it bound_! So, don't do that on Win32.
    - Change version parsing logic: a version is "obsolete" if it is not
      recommended and (1) there is a newer recommended version in the
      same series, or (2) there are no recommended versions in the same
      series, but there are some recommended versions in a newer series.
      A version is "new" if it is newer than any recommended version in
      the same series.
    - Stop most cases of hanging up on a socks connection without sending
      the socks reject.

  o Helpful fixes:
    - Require BandwidthRate to be at least 20kB/s for servers.
    - When a dirserver causes you to give a warn, mention which dirserver
      it was.
    - New config option DirAllowPrivateAddresses for authdirservers.
      Now by default they refuse router descriptors that have non-IP or
      private-IP addresses.
    - Stop publishing socksport in the directory, since it's not
      actually meant to be public. For compatibility, publish a 0 there
      for now.
    - Change DirFetchPeriod/StatusFetchPeriod to have a special "Be
      smart" value, that is low for servers and high for clients.
    - If our clock jumps forward by 100 seconds or more, assume something
      has gone wrong with our network and abandon all not-yet-used circs.
    - Warn when exit policy implicitly allows local addresses.
    - If we get an incredibly skewed timestamp from a dirserver mirror
      that isn't a verified OR, don't warn -- it's probably him that's
      wrong.
    - Since we ship our own Privoxy on OS X, tweak it so it doesn't write
      cookies to disk and doesn't log each web request to disk. (Thanks
      to Brett Carrington for pointing this out.)
    - When a client asks us for a dir mirror and we don't have one,
      launch an attempt to get a fresh one.
    - If we're hibernating and we get a SIGINT, exit immediately.
    - Add --with-dmalloc ./configure option, to track memory leaks.
    - And try to free all memory on closing, so we can detect what
      we're leaking.
    - Cache local dns resolves correctly even when they're .exit
      addresses.
    - Give a better warning when some other server advertises an
      ORPort that is actually an apache running ssl.
    - Add "opt hibernating 1" to server descriptor to make it clearer
      whether the server is hibernating.


Changes in version 0.0.9.6 - 2005-03-24
  o Bugfixes on 0.0.9.x (crashes and asserts):
    - Add new end stream reasons to maintainance branch. Fix bug where
      reason (8) could trigger an assert. Prevent bug from recurring.
    - Apparently win32 stat wants paths to not end with a slash.
    - Fix assert triggers in assert_cpath_layer_ok(), where we were
      blowing away the circuit that conn->cpath_layer points to, then
      checking to see if the circ is well-formed. Backport check to make
      sure we dont use the cpath on a closed connection.
    - Prevent circuit_resume_edge_reading_helper() from trying to package
      inbufs for marked-for-close streams.
    - Don't crash on hup if your options->address has become unresolvable.
    - Some systems (like OS X) sometimes accept() a connection and tell
      you the remote host is 0.0.0.0:0. If this happens, due to some
      other mis-features, we get confused; so refuse the conn for now.

  o Bugfixes on 0.0.9.x (other):
    - Fix harmless but scary "Unrecognized content encoding" warn message.
    - Add new stream error reason: TORPROTOCOL reason means "you are not
      speaking a version of Tor I understand; say bye-bye to your stream."
    - Be willing to cache directories from up to ROUTER_MAX_AGE seconds
      into the future, now that we are more tolerant of skew. This
      resolves a bug where a Tor server would refuse to cache a directory
      because all the directories it gets are too far in the future;
      yet the Tor server never logs any complaints about clock skew.
    - Mac packaging magic: make man pages useable, and do not overwrite
      existing torrc files.
    - Make OS X log happily to /var/log/tor/tor.log


Changes in version 0.0.9.5 - 2005-02-22
  o Bugfixes on 0.0.9.x:
    - Fix an assert race at exit nodes when resolve requests fail.
    - Stop picking unverified dir mirrors--it only leads to misery.
    - Patch from Matt Edman to make NT services work better. Service
      support is still not compiled into the executable by default.
    - Patch from Dmitri Bely so the Tor service runs better under
      the win32 SYSTEM account.
    - Make tor-resolve actually work (?) on Win32.
    - Fix a sign bug when getrlimit claims to have 4+ billion
      file descriptors available.
    - Stop refusing to start when bandwidthburst == bandwidthrate.
    - When create cells have been on the onion queue more than five
      seconds, just send back a destroy and take them off the list.


Changes in version 0.0.9.4 - 2005-02-03
  o Bugfixes on 0.0.9:
    - Fix an assert bug that took down most of our servers: when
      a server claims to have 1 GB of bandwidthburst, don't
      freak out.
    - Don't crash as badly if we have spawned the max allowed number
      of dnsworkers, or we're out of file descriptors.
    - Block more file-sharing ports in the default exit policy.
    - MaxConn is now automatically set to the hard limit of max
      file descriptors we're allowed (ulimit -n), minus a few for
      logs, etc.
    - Give a clearer message when servers need to raise their
      ulimit -n when they start running out of file descriptors.
    - SGI Compatibility patches from Jan Schaumann.
    - Tolerate a corrupt cached directory better.
    - When a dirserver hasn't approved your server, list which one.
    - Go into soft hibernation after 95% of the bandwidth is used,
      not 99%. This is especially important for daily hibernators who
      have a small accounting max. Hopefully it will result in fewer
      cut connections when the hard hibernation starts.
    - Load-balance better when using servers that claim more than
      800kB/s of capacity.
    - Make NT services work (experimental, only used if compiled in).


Changes in version 0.0.9.3 - 2005-01-21
  o Bugfixes on 0.0.9:
    - Backport the cpu use fixes from main branch, so busy servers won't
      need as much processor time.
    - Work better when we go offline and then come back, or when we
      run Tor at boot before the network is up. We do this by
      optimistically trying to fetch a new directory whenever an
      application request comes in and we think we're offline -- the
      human is hopefully a good measure of when the network is back.
    - Backport some minimal hidserv bugfixes: keep rend circuits open as
      long as you keep using them; actually publish hidserv descriptors
      shortly after they change, rather than waiting 20-40 minutes.
    - Enable Mac startup script by default.
    - Fix duplicate dns_cancel_pending_resolve reported by Giorgos Pallas.
    - When you update AllowUnverifiedNodes or FirewallPorts via the
      controller's setconf feature, we were always appending, never
      resetting.
    - When you update HiddenServiceDir via setconf, it was screwing up
      the order of reading the lines, making it fail.
    - Do not rewrite a cached directory back to the cache; otherwise we
      will think it is recent and not fetch a newer one on startup.
    - Workaround for webservers that lie about Content-Encoding: Tor
      now tries to autodetect compressed directories and compression
      itself. This lets us Proxypass dir fetches through apache.


Changes in version 0.0.9.2 - 2005-01-04
  o Bugfixes on 0.0.9 (crashes and asserts):
    - Fix an assert on startup when the disk is full and you're logging
      to a file.
    - If you do socks4 with an IP of 0.0.0.x but *don't* provide a socks4a
      style address, then we'd crash.
    - Fix an assert trigger when the running-routers string we get from
      a dirserver is broken.
    - Make worker threads start and run on win32. Now win32 servers
      may work better.
    - Bandaid (not actually fix, but now it doesn't crash) an assert
      where the dns worker dies mysteriously and the main Tor process
      doesn't remember anything about the address it was resolving.

  o Bugfixes on 0.0.9 (Win32):
    - Workaround for brain-damaged __FILE__ handling on MSVC: keep Nick's
      name out of the warning/assert messages.
    - Fix a superficial "unhandled error on read" bug on win32.
    - The win32 installer no longer requires a click-through for our
      license, since our Free Software license grants rights but does not
      take any away.
    - Win32: When connecting to a dirserver fails, try another one
      immediately. (This was already working for non-win32 Tors.)
    - Stop trying to parse $HOME on win32 when hunting for default
      DataDirectory.
    - Make tor-resolve.c work on win32 by calling network_init().

  o Bugfixes on 0.0.9 (other):
    - Make 0.0.9.x build on Solaris again.
    - Due to a fencepost error, we were blowing away the \n when reporting
      confvalue items in the controller. So asking for multiple config
      values at once couldn't work.
    - When listing circuits that are pending on an opening OR connection,
      if we're an OR we were listing circuits that *end* at us as
      being pending on every listener, dns/cpu worker, etc. Stop that.
    - Dirservers were failing to create 'running-routers' or 'directory'
      strings if we had more than some threshold of routers. Fix them so
      they can handle any number of routers.
    - Fix a superficial "Duplicate mark for close" bug.
    - Stop checking for clock skew for OR connections, even for servers.
    - Fix a fencepost error that was chopping off the last letter of any
      nickname that is the maximum allowed nickname length.
    - Update URLs in log messages so they point to the new website.
    - Fix a potential problem in mangling server private keys while
      writing to disk (not triggered yet, as far as we know).
    - Include the licenses for other free software we include in Tor,
      now that we're shipping binary distributions more regularly.


Changes in version 0.0.9.1 - 2004-12-15
  o Bugfixes on 0.0.9:
    - Make hibernation actually work.
    - Make HashedControlPassword config option work.
    - When we're reporting event circuit status to a controller,
      don't use the stream status code.


Changes in version 0.0.9 - 2004-12-12
  o Cleanups:
    - Clean up manpage and torrc.sample file.
    - Clean up severities and text of log warnings.
  o Mistakes:
    - Make servers trigger an assert when they enter hibernation.


Changes in version 0.0.9rc7 - 2004-12-08
  o Bugfixes on 0.0.9rc:
    - Fix a stack-trashing crash when an exit node begins hibernating.
    - Avoid looking at unallocated memory while considering which
      ports we need to build circuits to cover.
    - Stop a sigpipe: when an 'end' cell races with eof from the app,
      we shouldn't hold-open-until-flush if the eof arrived first.
    - Fix a bug with init_cookie_authentication() in the controller.
    - When recommending new-format log lines, if the upper bound is
      LOG_ERR, leave it implicit.

  o Bugfixes on 0.0.8.1:
    - Fix a whole slew of memory leaks.
    - Fix isspace() and friends so they still make Solaris happy
      but also so they don't trigger asserts on win32.
    - Fix parse_iso_time on platforms without strptime (eg win32).
    - win32: tolerate extra "readable" events better.
    - win32: when being multithreaded, leave parent fdarray open.
    - Make unit tests work on win32.


Changes in version 0.0.9rc6 - 2004-12-06
  o Bugfixes on 0.0.9pre:
    - Clean up some more integer underflow opportunities (not exploitable
      we think).
    - While hibernating, hup should not regrow our listeners.
    - Send an end to the streams we close when we hibernate, rather
      than just chopping them off.
    - React to eof immediately on non-open edge connections.

  o Bugfixes on 0.0.8.1:
    - Calculate timeout for waiting for a connected cell from the time
      we sent the begin cell, not from the time the stream started. If
      it took a long time to establish the circuit, we would time out
      right after sending the begin cell.
    - Fix router_compare_addr_to_addr_policy: it was not treating a port
      of * as always matching, so we were picking reject *:* nodes as
      exit nodes too. Oops.

  o Features:
    - New circuit building strategy: keep a list of ports that we've
      used in the past 6 hours, and always try to have 2 circuits open
      or on the way that will handle each such port. Seed us with port
      80 so web users won't complain that Tor is "slow to start up".
    - Make kill -USR1 dump more useful stats about circuits.
    - When warning about retrying or giving up, print the address, so
      the user knows which one it's talking about.
    - If you haven't used a clean circuit in an hour, throw it away,
      just to be on the safe side. (This means after 6 hours a totally
      unused Tor client will have no circuits open.)


Changes in version 0.0.9rc5 - 2004-12-01
  o Bugfixes on 0.0.8.1:
    - Disallow NDEBUG. We don't ever want anybody to turn off debug.
    - Let resolve conns retry/expire also, rather than sticking around
      forever.
    - If we are using select, make sure we stay within FD_SETSIZE.

  o Bugfixes on 0.0.9pre:
    - Fix integer underflow in tor_vsnprintf() that may be exploitable,
      but doesn't seem to be currently; thanks to Ilja van Sprundel for
      finding it.
    - If anybody set DirFetchPostPeriod, give them StatusFetchPeriod
      instead. Impose minima and maxima for all *Period options; impose
      even tighter maxima for fetching if we are a caching dirserver.
      Clip rather than rejecting.
    - Fetch cached running-routers from servers that serve it (that is,
      authdirservers and servers running 0.0.9rc5-cvs or later.)

  o Features:
    - Accept *:706 (silc) in default exit policy.
    - Implement new versioning format for post 0.1.
    - Support "foo.nickname.exit" addresses, to let Alice request the
      address "foo" as viewed by exit node "nickname". Based on a patch
      by Geoff Goodell.
    - Make tor --version --version dump the cvs Id of every file.


Changes in version 0.0.9rc4 - 2004-11-28
  o Bugfixes on 0.0.8.1:
    - Make windows sockets actually non-blocking (oops), and handle
      win32 socket errors better.

  o Bugfixes on 0.0.9rc1:
    - Actually catch the -USR2 signal.


Changes in version 0.0.9rc3 - 2004-11-25
  o Bugfixes on 0.0.8.1:
    - Flush the log file descriptor after we print "Tor opening log file",
      so we don't see those messages days later.

  o Bugfixes on 0.0.9rc1:
    - Make tor-resolve work again.
    - Avoid infinite loop in tor-resolve if tor hangs up on it.
    - Fix an assert trigger for clients/servers handling resolves.


Changes in version 0.0.9rc2 - 2004-11-24
  o Bugfixes on 0.0.9rc1:
    - I broke socks5 support while fixing the eof bug.
    - Allow unitless bandwidths and intervals; they default to bytes
      and seconds.
    - New servers don't start out hibernating; they are active until
      they run out of bytes, so they have a better estimate of how
      long it takes, and so their operators can know they're working.


Changes in version 0.0.9rc1 - 2004-11-23
  o Bugfixes on 0.0.8.1:
    - Finally fix a bug that's been plaguing us for a year:
      With high load, circuit package window was reaching 0. Whenever
      we got a circuit-level sendme, we were reading a lot on each
      socket, but only writing out a bit. So we would eventually reach
      eof. This would be noticed and acted on even when there were still
      bytes sitting in the inbuf.
    - When poll() is interrupted, we shouldn't believe the revents values.

  o Bugfixes on 0.0.9pre6:
    - Fix hibernate bug that caused pre6 to be broken.
    - Don't keep rephist info for routers that haven't had activity for
      24 hours. (This matters now that clients have keys, since we track
      them too.)
    - Never call close_temp_logs while validating log options.
    - Fix backslash-escaping on tor.sh.in and torctl.in.

  o Features:
    - Implement weekly/monthly/daily accounting: now you specify your
      hibernation properties by
      AccountingMax N bytes|KB|MB|GB|TB
      AccountingStart day|week|month [day] HH:MM
        Defaults to "month 1 0:00".
    - Let bandwidth and interval config options be specified as 5 bytes,
      kb, kilobytes, etc; and as seconds, minutes, hours, days, weeks.
    - kill -USR2 now moves all logs to loglevel debug (kill -HUP to
      get back to normal.)
    - If your requested entry or exit node has advertised bandwidth 0,
      pick it anyway.
    - Be more greedy about filling up relay cells -- we try reading again
      once we've processed the stuff we read, in case enough has arrived
      to fill the last cell completely.
    - Apply NT service patch from Osamu Fujino. Still needs more work.


Changes in version 0.0.9pre6 - 2004-11-15
  o Bugfixes on 0.0.8.1:
    - Fix assert failure on malformed socks4a requests.
    - Use identity comparison, not nickname comparison, to choose which
      half of circuit-ID-space each side gets to use. This is needed
      because sometimes we think of a router as a nickname, and sometimes
      as a hex ID, and we can't predict what the other side will do.
    - Catch and ignore SIGXFSZ signals when log files exceed 2GB; our
      write() call will fail and we handle it there.
    - Add a FAST_SMARTLIST define to optionally inline smartlist_get
      and smartlist_len, which are two major profiling offenders.

  o Bugfixes on 0.0.9pre5:
    - Fix a bug in read_all that was corrupting config files on windows.
    - When we're raising the max number of open file descriptors to
      'unlimited', don't log that we just raised it to '-1'.
    - Include event code with events, as required by control-spec.txt.
    - Don't give a fingerprint when clients do --list-fingerprint:
      it's misleading, because it will never be the same again.
    - Stop using strlcpy in tor_strndup, since it was slowing us
      down a lot.
    - Remove warn on startup about missing cached-directory file.
    - Make kill -USR1 work again.
    - Hibernate if we start tor during the "wait for wakeup-time" phase
      of an accounting interval. Log our hibernation plans better.
    - Authoritative dirservers now also cache their directory, so they
      have it on start-up.

  o Features:
    - Fetch running-routers; cache running-routers; compress
      running-routers; serve compressed running-routers.z
    - Add NSI installer script contributed by J Doe.
    - Commit VC6 and VC7 workspace/project files.
    - Commit a tor.spec for making RPM files, with help from jbash.
    - Add contrib/torctl.in contributed by Glenn Fink.
    - Implement the control-spec's SAVECONF command, to write your
      configuration to torrc.
    - Get cookie authentication for the controller closer to working.
    - Include control-spec.txt in the tarball.
    - When set_conf changes our server descriptor, upload a new copy.
      But don't upload it too often if there are frequent changes.
    - Document authentication config in man page, and document signals
      we catch.
    - Clean up confusing parts of man page and torrc.sample.
    - Make expand_filename handle ~ and ~username.
    - Use autoconf to enable largefile support where necessary. Use
      ftello where available, since ftell can fail at 2GB.
    - Distinguish between TOR_TLS_CLOSE and TOR_TLS_ERROR, so we can
      log more informatively.
    - Give a slightly more useful output for "tor -h".
    - Refuse application socks connections to port 0.
    - Check clock skew for verified servers, but allow unverified
      servers and clients to have any clock skew.
    - Break DirFetchPostPeriod into:
      - DirFetchPeriod for fetching full directory,
      - StatusFetchPeriod for fetching running-routers,
      - DirPostPeriod for posting server descriptor,
      - RendPostPeriod for posting hidden service descriptors.
    - Make sure the hidden service descriptors are at a random offset
      from each other, to hinder linkability.


Changes in version 0.0.9pre5 - 2004-11-09
  o Bugfixes on 0.0.9pre4:
    - Fix a seg fault in unit tests (doesn't affect main program).
    - Fix an assert bug where a hidden service provider would fail if
      the first hop of his rendezvous circuit was down.
    - Hidden service operators now correctly handle version 1 style
      INTRODUCE1 cells (nobody generates them still, so not a critical
      bug).
    - If do_hup fails, actually notice.
    - Handle more errnos from accept() without closing the listener.
      Some OpenBSD machines were closing their listeners because
      they ran out of file descriptors.
    - Send resolve cells to exit routers that are running a new
      enough version of the resolve code to work right.
    - Better handling of winsock includes on non-MSV win32 compilers.
    - Some people had wrapped their tor client/server in a script
      that would restart it whenever it died. This did not play well
      with our "shut down if your version is obsolete" code. Now people
      don't fetch a new directory if their local cached version is
      recent enough.
    - Make our autogen.sh work on ksh as well as bash.

  o Major Features:
    - Hibernation: New config option "AccountingMaxKB" lets you
      set how many KBytes per month you want to allow your server to
      consume. Rather than spreading those bytes out evenly over the
      month, we instead hibernate for some of the month and pop up
      at a deterministic time, work until the bytes are consumed, then
      hibernate again. Config option "MonthlyAccountingStart" lets you
      specify which day of the month your billing cycle starts on.
    - Control interface: a separate program can now talk to your
      client/server over a socket, and get/set config options, receive
      notifications of circuits and streams starting/finishing/dying,
      bandwidth used, etc. The next step is to get some GUIs working.
      Let us know if you want to help out. See doc/control-spec.txt .
    - Ship a contrib/tor-control.py as an example script to interact
      with the control port.
    - "tor --hash-password zzyxz" will output a salted password for
      use in authenticating to the control interface.
    - New log format in config:
      "Log minsev[-maxsev] stdout|stderr|syslog" or
      "Log minsev[-maxsev] file /var/foo"

  o Minor Features:
    - DirPolicy config option, to let people reject incoming addresses
      from their dirserver.
    - "tor --list-fingerprint" will list your identity key fingerprint
      and then exit.
    - Add "pass" target for RedirectExit, to make it easier to break
      out of a sequence of RedirectExit rules.
    - Clients now generate a TLS cert too, in preparation for having
      them act more like real nodes.
    - Ship src/win32/ in the tarball, so people can use it to build.
    - Make old win32 fall back to CWD if SHGetSpecialFolderLocation
      is broken.
    - New "router-status" line in directory, to better bind each verified
      nickname to its identity key.
    - Deprecate unofficial config option abbreviations, and abbreviations
      not on the command line.
    - Add a pure-C tor-resolve implementation.
    - Use getrlimit and friends to ensure we can reach MaxConn (currently
      1024) file descriptors.

  o Code security improvements, inspired by Ilja:
    - Replace sprintf with snprintf. (I think they were all safe, but
      hey.)
    - Replace strcpy/strncpy with strlcpy in more places.
    - Avoid strcat; use snprintf or strlcat instead.
    - snprintf wrapper with consistent (though not C99) overflow behavior.


Changes in version 0.0.9pre4 - 2004-10-17
  o Bugfixes on 0.0.9pre3:
    - If the server doesn't specify an exit policy, use the real default
      exit policy, not reject *:*.
    - Ignore fascistfirewall when uploading/downloading hidden service
      descriptors, since we go through Tor for those; and when using
      an HttpProxy, since we assume it can reach them all.
    - When looking for an authoritative dirserver, use only the ones
      configured at boot. Don't bother looking in the directory.
    - The rest of the fix for get_default_conf_file() on older win32.
    - Make 'Routerfile' config option obsolete.

  o Features:
    - New 'MyFamily nick1,...' config option for a server to
      specify other servers that shouldn't be used in the same circuit
      with it. Only believed if nick1 also specifies us.
    - New 'NodeFamily nick1,nick2,...' config option for a client to
      specify nodes that it doesn't want to use in the same circuit.
    - New 'Redirectexit pattern address:port' config option for a
      server to redirect exit connections, e.g. to a local squid.


Changes in version 0.0.9pre3 - 2004-10-13
  o Bugfixes on 0.0.8.1:
    - Better torrc example lines for dirbindaddress and orbindaddress.
    - Improved bounds checking on parsed ints (e.g. config options and
      the ones we find in directories.)
    - Better handling of size_t vs int, so we're more robust on 64
      bit platforms.
    - Fix the rest of the bug where a newly started OR would appear
      as unverified even after we've added his fingerprint and hupped
      the dirserver.
    - Fix a bug from 0.0.7: when read() failed on a stream, we would
      close it without sending back an end. So 'connection refused'
      would simply be ignored and the user would get no response.

  o Bugfixes on 0.0.9pre2:
    - Serving the cached-on-disk directory to people is bad. We now
      provide no directory until we've fetched a fresh one.
    - Workaround for bug on windows where cached-directories get crlf
      corruption.
    - Make get_default_conf_file() work on older windows too.
    - If we write a *:* exit policy line in the descriptor, don't write
      any more exit policy lines.

  o Features:
    - Use only 0.0.9pre1 and later servers for resolve cells.
    - Make the dirservers file obsolete.
      - Include a dir-signing-key token in directories to tell the
        parsing entity which key is being used to sign.
      - Remove the built-in bulky default dirservers string.
      - New config option "Dirserver %s:%d [fingerprint]", which can be
        repeated as many times as needed. If no dirservers specified,
        default to moria1,moria2,tor26.
    - Make moria2 advertise a dirport of 80, so people behind firewalls
      will be able to get a directory.
    - Http proxy support
      - Dirservers translate requests for http://%s:%d/x to /x
      - You can specify "HttpProxy %s[:%d]" and all dir fetches will
        be routed through this host.
      - Clients ask for /tor/x rather than /x for new enough dirservers.
        This way we can one day coexist peacefully with apache.
      - Clients specify a "Host: %s%d" http header, to be compatible
        with more proxies, and so running squid on an exit node can work.


Changes in version 0.0.8.1 - 2004-10-13
  o Bugfixes:
    - Fix a seg fault that can be triggered remotely for Tor
      clients/servers with an open dirport.
    - Fix a rare assert trigger, where routerinfos for entries in
      our cpath would expire while we're building the path.
    - Fix a bug in OutboundBindAddress so it (hopefully) works.
    - Fix a rare seg fault for people running hidden services on
      intermittent connections.
    - Fix a bug in parsing opt keywords with objects.
    - Fix a stale pointer assert bug when a stream detaches and
      reattaches.
    - Fix a string format vulnerability (probably not exploitable)
      in reporting stats locally.
    - Fix an assert trigger: sometimes launching circuits can fail
      immediately, e.g. because too many circuits have failed recently.
    - Fix a compile warning on 64 bit platforms.


Changes in version 0.0.9pre2 - 2004-10-03
  o Bugfixes:
    - Make fetching a cached directory work for 64-bit platforms too.
    - Make zlib.h a required header, not an optional header.


Changes in version 0.0.9pre1 - 2004-10-01
  o Bugfixes:
    - Stop using separate defaults for no-config-file and
      empty-config-file. Now you have to explicitly turn off SocksPort,
      if you don't want it open.
    - Fix a bug in OutboundBindAddress so it (hopefully) works.
    - Improve man page to mention more of the 0.0.8 features.
    - Fix a rare seg fault for people running hidden services on
      intermittent connections.
    - Change our file IO stuff (especially wrt OpenSSL) so win32 is
      happier.
    - Fix more dns related bugs: send back resolve_failed and end cells
      more reliably when the resolve fails, rather than closing the
      circuit and then trying to send the cell. Also attach dummy resolve
      connections to a circuit *before* calling dns_resolve(), to fix
      a bug where cached answers would never be sent in RESOLVED cells.
    - When we run out of disk space, or other log writing error, don't
      crash. Just stop logging to that log and continue.
    - We were starting to daemonize before we opened our logs, so if
      there were any problems opening logs, we would complain to stderr,
      which wouldn't work, and then mysteriously exit.
    - Fix a rare bug where sometimes a verified OR would connect to us
      before he'd uploaded his descriptor, which would cause us to
      assign conn->nickname as though he's unverified. Now we look through
      the fingerprint list to see if he's there.
    - Fix a rare assert trigger, where routerinfos for entries in
      our cpath would expire while we're building the path.

  o Features:
    - Clients can ask dirservers for /dir.z to get a compressed version
      of the directory. Only works for servers running 0.0.9, of course.
    - Make clients cache directories and use them to seed their router
      lists at startup. This means clients have a datadir again.
    - Configuration infrastructure support for warning on obsolete
      options.
    - Respond to content-encoding headers by trying to uncompress as
      appropriate.
    - Reply with a deflated directory when a client asks for "dir.z".
      We could use allow-encodings instead, but allow-encodings isn't
      specified in HTTP 1.0.
    - Raise the max dns workers from 50 to 100.
    - Discourage people from setting their dirfetchpostperiod more often
      than once per minute.
    - Protect dirservers from overzealous descriptor uploading -- wait
      10 seconds after directory gets dirty, before regenerating.


Changes in version 0.0.8 - 2004-08-25
  o Port it to SunOS 5.9 / Athena


Changes in version 0.0.8rc2 - 2004-08-20
  o Make it compile on cygwin again.
  o When picking unverified routers, skip those with low uptime and/or
    low bandwidth, depending on what properties you care about.


Changes in version 0.0.8rc1 - 2004-08-18
  o Changes from 0.0.7.3:
    - Bugfixes:
      - Fix assert triggers: if the other side returns an address 0.0.0.0,
        don't put it into the client dns cache.
      - If a begin failed due to exit policy, but we believe the IP address
        should have been allowed, switch that router to exitpolicy reject *:*
        until we get our next directory.
    - Features:
      - Clients choose nodes proportional to advertised bandwidth.
      - Avoid using nodes with low uptime as introduction points.
      - Handle servers with dynamic IP addresses: don't replace
        options->Address with the resolved one at startup, and
        detect our address right before we make a routerinfo each time.
      - 'FascistFirewall' option to pick dirservers and ORs on specific
        ports; plus 'FirewallPorts' config option to tell FascistFirewall
        which ports are open. (Defaults to 80,443)
      - Be more aggressive about trying to make circuits when the network
        has changed (e.g. when you unsuspend your laptop).
      - Check for time skew on http headers; report date in response to
        "GET /".
      - If the entrynode config line has only one node, don't pick it as
        an exitnode.
      - Add strict{entry|exit}nodes config options. If set to 1, then
        we refuse to build circuits that don't include the specified entry
        or exit nodes.
      - OutboundBindAddress config option, to bind to a specific
        IP address for outgoing connect()s.
      - End truncated log entries (e.g. directories) with "[truncated]".

  o Patches to 0.0.8preX:
    - Bugfixes:
      - Patches to compile and run on win32 again (maybe)?
      - Fix crash when looking for ~/.torrc with no $HOME set.
      - Fix a race bug in the unit tests.
      - Handle verified/unverified name collisions better when new
        routerinfo's arrive in a directory.
      - Sometimes routers were getting entered into the stats before
        we'd assigned their identity_digest. Oops.
      - Only pick and establish intro points after we've gotten a
        directory.
    - Features:
      - AllowUnverifiedNodes config option to let circuits choose no-name
        routers in entry,middle,exit,introduction,rendezvous positions.
        Allow middle and rendezvous positions by default.
      - Add a man page for tor-resolve.


Changes in version 0.0.7.3 - 2004-08-12
  o Stop dnsworkers from triggering an assert failure when you
    ask them to resolve the host "".


Changes in version 0.0.8pre3 - 2004-08-09
  o Changes from 0.0.7.2:
    - Allow multiple ORs with same nickname in routerlist -- now when
      people give us one identity key for a nickname, then later
      another, we don't constantly complain until the first expires.
    - Remember used bandwidth (both in and out), and publish 15-minute
      snapshots for the past day into our descriptor.
    - You can now fetch $DIRURL/running-routers to get just the
      running-routers line, not the whole descriptor list. (But
      clients don't use this yet.)
    - When people mistakenly use Tor as an http proxy, point them
      at the tor-doc.html rather than the INSTALL.
    - Remove our mostly unused -- and broken -- hex_encode()
      function. Use base16_encode() instead. (Thanks to Timo Lindfors
      for pointing out this bug.)
    - Rotate onion keys every 12 hours, not every 2 hours, so we have
      fewer problems with people using the wrong key.
    - Change the default exit policy to reject the default edonkey,
      kazaa, gnutella ports.
    - Add replace_file() to util.[ch] to handle win32's rename().

  o Changes from 0.0.8preX:
    - Fix two bugs in saving onion keys to disk when rotating, so
      hopefully we'll get fewer people using old onion keys.
    - Fix an assert error that was making SocksPolicy not work.
    - Be willing to expire routers that have an open dirport -- it's
      just the authoritative dirservers we want to not forget.
    - Reject tor-resolve requests for .onion addresses early, so we
      don't build a whole rendezvous circuit and then fail.
    - When you're warning a server that he's unverified, don't cry
      wolf unpredictably.
    - Fix a race condition: don't try to extend onto a connection
      that's still handshaking.
    - For servers in clique mode, require the conn to be open before
      you'll choose it for your path.
    - Fix some cosmetic bugs about duplicate mark-for-close, lack of
      end relay cell, etc.
    - Measure bandwidth capacity over the last 24 hours, not just 12
    - Bugfix: authoritative dirservers were making and signing a new
      directory for each client, rather than reusing the cached one.


Changes in version 0.0.8pre2 - 2004-08-04
  o Changes from 0.0.7.2:
    - Security fixes:
      - Check directory signature _before_ you decide whether you're
        you're running an obsolete version and should exit.
      - Check directory signature _before_ you parse the running-routers
        list to decide who's running or verified.
    - Bugfixes and features:
      - Check return value of fclose while writing to disk, so we don't
        end up with broken files when servers run out of disk space.
      - Log a warning if the user uses an unsafe socks variant, so people
        are more likely to learn about privoxy or socat.
      - Dirservers now include RFC1123-style dates in the HTTP headers,
        which one day we will use to better detect clock skew.

  o Changes from 0.0.8pre1:
    - Make it compile without warnings again on win32.
    - Log a warning if you're running an unverified server, to let you
      know you might want to get it verified.
    - Only pick a default nickname if you plan to be a server.


Changes in version 0.0.8pre1 - 2004-07-23
  o Bugfixes:
    - Made our unit tests compile again on OpenBSD 3.5, and tor
      itself compile again on OpenBSD on a sparc64.
    - We were neglecting milliseconds when logging on win32, so
      everything appeared to happen at the beginning of each second.

  o Protocol changes:
    - 'Extend' relay cell payloads now include the digest of the
      intended next hop's identity key. Now we can verify that we're
      extending to the right router, and also extend to routers we
      hadn't heard of before.

  o Features:
    - Tor nodes can now act as relays (with an advertised ORPort)
      without being manually verified by the dirserver operators.
      - Uploaded descriptors of unverified routers are now accepted
        by the dirservers, and included in the directory.
      - Verified routers are listed by nickname in the running-routers
        list; unverified routers are listed as "$<fingerprint>".
      - We now use hash-of-identity-key in most places rather than
        nickname or addr:port, for improved security/flexibility.
      - To avoid Sybil attacks, paths still use only verified servers.
        But now we have a chance to play around with hybrid approaches.
      - Nodes track bandwidth usage to estimate capacity (not used yet).
      - ClientOnly option for nodes that never want to become servers.
    - Directory caching.
      - "AuthoritativeDir 1" option for the official dirservers.
      - Now other nodes (clients and servers) will cache the latest
        directory they've pulled down.
      - They can enable their DirPort to serve it to others.
      - Clients will pull down a directory from any node with an open
        DirPort, and check the signature/timestamp correctly.
      - Authoritative dirservers now fetch directories from other
        authdirservers, to stay better synced.
      - Running-routers list tells who's down also, along with noting
        if they're verified (listed by nickname) or unverified (listed
        by hash-of-key).
      - Allow dirservers to serve running-router list separately.
        This isn't used yet.
    - ORs connect-on-demand to other ORs
      - If you get an extend cell to an OR you're not connected to,
        connect, handshake, and forward the create cell.
      - The authoritative dirservers stay connected to everybody,
        and everybody stays connected to 0.0.7 servers, but otherwise
        clients/servers expire unused connections after 5 minutes.
    - When servers get a sigint, they delay 30 seconds (refusing new
      connections) then exit. A second sigint causes immediate exit.
    - File and name management:
      - Look for .torrc if no CONFDIR "torrc" is found.
      - If no datadir is defined, then choose, make, and secure ~/.tor
        as datadir.
      - If torrc not found, exitpolicy reject *:*.
      - Expands ~/ in filenames to $HOME/ (but doesn't yet expand ~arma).
      - If no nickname is defined, derive default from hostname.
      - Rename secret key files, e.g. identity.key -> secret_id_key,
        to discourage people from mailing their identity key to tor-ops.
    - Refuse to build a circuit before the directory has arrived --
      it won't work anyway, since you won't know the right onion keys
      to use.
    - Try other dirservers immediately if the one you try is down. This
      should tolerate down dirservers better now.
    - Parse tor version numbers so we can do an is-newer-than check
      rather than an is-in-the-list check.
    - New socks command 'resolve', to let us shim gethostbyname()
      locally.
      - A 'tor_resolve' script to access the socks resolve functionality.
      - A new socks-extensions.txt doc file to describe our
        interpretation and extensions to the socks protocols.
    - Add a ContactInfo option, which gets published in descriptor.
    - Publish OR uptime in descriptor (and thus in directory) too.
    - Write tor version at the top of each log file
    - New docs in the tarball:
      - tor-doc.html.
      - Document that you should proxy your SSL traffic too.


Changes in version 0.0.7.2 - 2004-07-07
  o A better fix for the 0.0.0.0 problem, that will hopefully
    eliminate the remaining related assertion failures.


Changes in version 0.0.7.1 - 2004-07-04
  o When an address resolves to 0.0.0.0, treat it as a failed resolve,
    since internally we use 0.0.0.0 to signify "not yet resolved".


Changes in version 0.0.7 - 2004-06-07
  o Updated the man page to reflect the new features.


Changes in version 0.0.7rc2 - 2004-06-06
  o Changes from 0.0.7rc1:
    - Make it build on Win32 again.
  o Changes from 0.0.6.2:
    - Rotate dnsworkers and cpuworkers on SIGHUP, so they get new config
      settings too.


Changes in version 0.0.7rc1 - 2004-06-02
  o Bugfixes:
    - On sighup, we were adding another log without removing the first
      one. So log messages would get duplicated n times for n sighups.
    - Several cases of using a connection after we'd freed it. The
      problem was that connections that are pending resolve are in both
      the pending_resolve tree, and also the circuit's resolving_streams
      list. When you want to remove one, you must remove it from both.
    - Fix a double-mark-for-close where an end cell arrived for a
      resolving stream, and then the resolve failed.
    - Check directory signatures based on name of signer, not on whom
      we got the directory from. This will let us cache directories more
      easily.
  o Features:
    - Crank up some of our constants to handle more users.


Changes in version 0.0.7pre1 - 2004-06-02
  o Fixes for crashes and other obnoxious bugs:
    - Fix an epipe bug: sometimes when directory connections failed
      to connect, we would give them a chance to flush before closing
      them.
    - When we detached from a circuit because of resolvefailed, we
      would immediately try the same circuit twice more, and then
      give up on the resolve thinking we'd tried three different
      exit nodes.
    - Limit the number of intro circuits we'll attempt to build for a
      hidden service per 15-minute period.
    - Check recommended-software string *early*, before actually parsing
      the directory. Thus we can detect an obsolete version and exit,
      even if the new directory format doesn't parse.
  o Fixes for security bugs:
    - Remember which nodes are dirservers when you startup, and if a
      random OR enables his dirport, don't automatically assume he's
      a trusted dirserver.
  o Other bugfixes:
    - Directory connections were asking the wrong poll socket to
      start writing, and not asking themselves to start writing.
    - When we detached from a circuit because we sent a begin but
      didn't get a connected, we would use it again the first time;
      but after that we would correctly switch to a different one.
    - Stop warning when the first onion decrypt attempt fails; they
      will sometimes legitimately fail now that we rotate keys.
    - Override unaligned-access-ok check when $host_cpu is ia64 or
      arm. Apparently they allow it but the kernel whines.
    - Dirservers try to reconnect periodically too, in case connections
      have failed.
    - Fix some memory leaks in directory servers.
    - Allow backslash in Win32 filenames.
    - Made Tor build complain-free on FreeBSD, hopefully without
      breaking other BSD builds. We'll see.
  o Features:
    - Doxygen markup on all functions and global variables.
    - Make directory functions update routerlist, not replace it. So
      now directory disagreements are not so critical a problem.
    - Remove the upper limit on number of descriptors in a dirserver's
      directory (not that we were anywhere close).
    - Allow multiple logfiles at different severity ranges.
    - Allow *BindAddress to specify ":port" rather than setting *Port
      separately. Allow multiple instances of each BindAddress config
      option, so you can bind to multiple interfaces if you want.
    - Allow multiple exit policy lines, which are processed in order.
      Now we don't need that huge line with all the commas in it.
    - Enable accept/reject policies on SOCKS connections, so you can bind
      to 0.0.0.0 but still control who can use your OP.


Changes in version 0.0.6.2 - 2004-05-16
  o Our integrity-checking digest was checking only the most recent cell,
    not the previous cells like we'd thought.
    Thanks to Stefan Mark for finding the flaw!


Changes in version 0.0.6.1 - 2004-05-06
  o Fix two bugs in our AES counter-mode implementation (this affected
    onion-level stream encryption, but not TLS-level). It turns
    out we were doing something much more akin to a 16-character
    polyalphabetic cipher. Oops.
    Thanks to Stefan Mark for finding the flaw!
  o Retire moria3 as a directory server, and add tor26 as a directory
    server.


Changes in version 0.0.6 - 2004-05-02
  [version bump only]


Changes in version 0.0.6rc4 - 2004-05-01
  o Update the built-in dirservers list to use the new directory format
  o Fix a rare seg fault: if a node offering a hidden service attempts
    to build a circuit to Alice's rendezvous point and fails before it
    reaches the last hop, it retries with a different circuit, but
    then dies.
  o Handle windows socket errors correctly.


Changes in version 0.0.6rc3 - 2004-04-28
  o Don't expire non-general excess circuits (if we had enough
    circuits open, we were expiring rendezvous circuits -- even
    when they had a stream attached. oops.)
  o Fetch randomness from /dev/urandom better (not via fopen/fread)
  o Better debugging for tls errors
  o Some versions of openssl have an SSL_pending function that erroneously
    returns bytes when there is a non-application record pending.
  o Set Content-Type on the directory and hidserv descriptor.
  o Remove IVs from cipher code, since AES-ctr has none.
  o Win32 fixes. Tor now compiles on win32 with no warnings/errors.
    o We were using an array of length zero in a few places.
    o win32's gethostbyname can't resolve an IP to an IP.
    o win32's close can't close a socket.


Changes in version 0.0.6rc2 - 2004-04-26
  o Fix a bug where we were closing tls connections intermittently.
    It turns out openssl keeps its errors around -- so if an error
    happens, and you don't ask about it, and then another openssl
    operation happens and succeeds, and you ask if there was an error,
    it tells you about the first error. Fun fun.
  o Fix a bug that's been lurking since 27 may 03 (!)
    When passing back a destroy cell, we would use the wrong circ id.
    'Mostly harmless', but still worth fixing.
  o Since we don't support truncateds much, don't bother sending them;
    just close the circ.
  o check for <machine/limits.h> so we build on NetBSD again (I hope).
  o don't crash if a conn that sent a begin has suddenly lost its circuit
    (this was quite rare).


Changes in version 0.0.6rc1 - 2004-04-25
  o We now rotate link (tls context) keys and onion keys.
  o CREATE cells now include oaep padding, so you can tell
    if you decrypted them correctly.
  o Add bandwidthburst to server descriptor.
  o Directories now say which dirserver signed them.
  o Use a tor_assert macro that logs failed assertions too.


Changes in version 0.0.6pre5 - 2004-04-18
  o changes from 0.0.6pre4:
    - make tor build on broken freebsd 5.2 installs
    - fix a failed assert when you try an intro point, get a nack, and try
      a second one and it works.
    - when alice uses a port that the hidden service doesn't accept,
      it now sends back an end cell (denied by exit policy). otherwise
      alice would just have to wait to time out.
    - fix another rare bug: when we had tried all the intro
      points for a hidden service, we fetched the descriptor
      again, but we left our introcirc thinking it had already
      sent an intro, so it kept waiting for a response...
    - bugfix: when you sleep your hidden-service laptop, as soon
      as it wakes up it tries to upload a service descriptor, but
      socketpair fails for some reason (localhost not up yet?).
      now we simply give up on that upload, and we'll try again later.
      i'd still like to find the bug though.
    - if an intro circ waiting for an ack dies before getting one, then
      count it as a nack
    - we were reusing stale service descriptors and refetching usable
      ones. oops.


Changes in version 0.0.6pre4 - 2004-04-14
  o changes from 0.0.6pre3:
    - when bob fails to connect to the rendezvous point, and his
      circ didn't fail because of the rendezvous point itself, then
      he retries a couple of times
    - we expire introduction and rendezvous circs more thoroughly
      (sometimes they were hanging around forever)
    - we expire unattached rendezvous streams that have been around
      too long (they were sticking around forever).
    - fix a measly fencepost error that was crashing everybody with
      a strict glibc.


Changes in version 0.0.6pre3 - 2004-04-14
  o changes from 0.0.6pre2:
    - make hup work again
    - fix some memory leaks for dirservers
    - allow more skew in rendezvous descriptor timestamps, to help
      handle people like blanu who don't know what time it is
    - normal circs are 3 hops, but some rend/intro circs are 4, if
      the initiator doesn't get to choose the last hop
    - send acks for introductions, so alice can know whether to try
      again
    - bob publishes intro points more correctly
  o changes from 0.0.5:
    - fix an assert trigger that's been plaguing us since the days
      of 0.0.2prexx (thanks weasel!)
    - retry stream correctly when we fail to connect because of
      exit-policy-reject (should try another) or can't-resolve-address
      (also should try another, because dns on random internet servers
      is flaky).
    - when we hup a dirserver and we've *removed* a server from the
      approved-routers list, now we remove that server from the
      in-memory directories too


Changes in version 0.0.6pre2 - 2004-04-08
  o We fixed our base32 implementation. Now it works on all architectures.


Changes in version 0.0.6pre1 - 2004-04-08
  o Features:
    - Hidden services and rendezvous points are implemented. Go to
      http://6sxoyfb3h2nvok2d.onion/ for an index of currently available
      hidden services. (This only works via a socks4a proxy such as
      Privoxy, and currently it's quite slow.)


Changes in version 0.0.5 - 2004-03-30
  [version bump only]


Changes in version 0.0.5rc3 - 2004-03-29
  o Install torrc as torrc.sample -- we no longer clobber your
    torrc. (Woo!)
  o Re-enable recommendedversion checking (we broke it in rc2, oops)
  o Add in a 'notice' log level for things the operator should hear
    but that aren't warnings


Changes in version 0.0.5rc2 - 2004-03-29
  o Hold socks connection open until reply is flushed (if possible)
  o Make exit nodes resolve IPs to IPs immediately, rather than asking
    the dns farm to do it.
  o Fix c99 aliasing warnings in rephist.c
  o Don't include server descriptors that are older than 24 hours in the
    directory.
  o Give socks 'reject' replies their whole 15s to attempt to flush,
    rather than seeing the 60s timeout and assuming the flush had failed.
  o Clean automake droppings from the cvs repository


Changes in version 0.0.5rc1 - 2004-03-28
  o Fix mangled-state bug in directory fetching (was causing sigpipes).
  o Only build circuits after we've fetched the directory: clients were
    using only the directory servers before they'd fetched a directory.
    This also means longer startup time; so it goes.
  o Fix an assert trigger where an OP would fail to handshake, and we'd
    expect it to have a nickname.
  o Work around a tsocks bug: do a socks reject when AP connection dies
    early, else tsocks goes into an infinite loop.


Changes in version 0.0.4 - 2004-03-26
  o When connecting to a dirserver or OR and the network is down,
    we would crash.


Changes in version 0.0.3 - 2004-03-26
  o Warn and fail if server chose a nickname with illegal characters
  o Port to Solaris and Sparc:
    - include missing header fcntl.h
    - have autoconf find -lsocket -lnsl automatically
    - deal with hardware word alignment
    - make uname() work (solaris has a different return convention)
    - switch from using signal() to sigaction()
  o Preliminary work on reputation system:
    - Keep statistics on success/fail of connect attempts; they're published
      by kill -USR1 currently.
    - Add a RunTesting option to try to learn link state by creating test
      circuits, even when SocksPort is off.
    - Remove unused open circuits when there are too many.


Changes in version 0.0.2 - 2004-03-19
    - Include strlcpy and strlcat for safer string ops
    - define INADDR_NONE so we compile (but still not run) on solaris


Changes in version 0.0.2pre27 - 2004-03-14
  o Bugfixes:
    - Allow internal tor networks (we were rejecting internal IPs,
      now we allow them if they're set explicitly).
    - And fix a few endian issues.


Changes in version 0.0.2pre26 - 2004-03-14
  o New features:
    - If a stream times out after 15s without a connected cell, don't
      try that circuit again: try a new one.
    - Retry streams at most 4 times. Then give up.
    - When a dirserver gets a descriptor from an unknown router, it
      logs its fingerprint (so the dirserver operator can choose to
      accept it even without mail from the server operator).
    - Inform unapproved servers when we reject their descriptors.
    - Make tor build on Windows again. It works as a client, who knows
      about as a server.
    - Clearer instructions in the torrc for how to set up a server.
    - Be more efficient about reading fd's when our global token bucket
      (used for rate limiting) becomes empty.
  o Bugfixes:
    - Stop asserting that computers always go forward in time. It's
      simply not true.
    - When we sent a cell (e.g. destroy) and then marked an OR connection
      expired, we might close it before finishing a flush if the other
      side isn't reading right then.
    - Don't allow dirservers to start if they haven't defined
      RecommendedVersions
    - We were caching transient dns failures. Oops.
    - Prevent servers from publishing an internal IP as their address.
    - Address a strcat vulnerability in circuit.c


Changes in version 0.0.2pre25 - 2004-03-04
  o New features:
    - Put the OR's IP in its router descriptor, not its fqdn. That way
      we'll stop being stalled by gethostbyname for nodes with flaky dns,
      e.g. poblano.
  o Bugfixes:
    - If the user typed in an address that didn't resolve, the server
      crashed.


Changes in version 0.0.2pre24 - 2004-03-03
  o Bugfixes:
    - Fix an assertion failure in dns.c, where we were trying to dequeue
      a pending dns resolve even if it wasn't pending
    - Fix a spurious socks5 warning about still trying to write after the
      connection is finished.
    - Hold certain marked_for_close connections open until they're finished
      flushing, rather than losing bytes by closing them too early.
    - Correctly report the reason for ending a stream
    - Remove some duplicate calls to connection_mark_for_close
    - Put switch_id and start_daemon earlier in the boot sequence, so it
      will actually try to chdir() to options.DataDirectory
    - Make 'make test' exit(1) if a test fails; fix some unit tests
    - Make tor fail when you use a config option it doesn't know about,
      rather than warn and continue.
    - Make --version work
    - Bugfixes on the rpm spec file and tor.sh, so it's more up to date


Changes in version 0.0.2pre23 - 2004-02-29
  o New features:
    - Print a statement when the first circ is finished, so the user
      knows it's working.
    - If a relay cell is unrecognized at the end of the circuit,
      send back a destroy. (So attacks to mutate cells are more
      clearly thwarted.)
    - New config option 'excludenodes' to avoid certain nodes for circuits.
    - When it daemonizes, it chdir's to the DataDirectory rather than "/",
      so you can collect coredumps there.
 o Bugfixes:
    - Fix a bug in tls flushing where sometimes data got wedged and
      didn't flush until more data got sent. Hopefully this bug was
      a big factor in the random delays we were seeing.
    - Make 'connected' cells include the resolved IP, so the client
      dns cache actually gets populated.
    - Disallow changing from ORPort=0 to ORPort>0 on hup.
    - When we time-out on a stream and detach from the circuit, send an
      end cell down it first.
    - Only warn about an unknown router (in exitnodes, entrynodes,
      excludenodes) after we've fetched a directory.


Changes in version 0.0.2pre22 - 2004-02-26
  o New features:
    - Servers publish less revealing uname information in descriptors.
    - More memory tracking and assertions, to crash more usefully when
      errors happen.
    - If the default torrc isn't there, just use some default defaults.
      Plus provide an internal dirservers file if they don't have one.
    - When the user tries to use Tor as an http proxy, give them an http
      501 failure explaining that we're a socks proxy.
    - Dump a new router.desc on hup, to help confused people who change
      their exit policies and then wonder why router.desc doesn't reflect
      it.
    - Clean up the generic tor.sh init script that we ship with.
  o Bugfixes:
    - If the exit stream is pending on the resolve, and a destroy arrives,
      then the stream wasn't getting removed from the pending list. I
      think this was the one causing recent server crashes.
    - Use a more robust poll on OSX 10.3, since their poll is flaky.
    - When it couldn't resolve any dirservers, it was useless from then on.
      Now it reloads the RouterFile (or default dirservers) if it has no
      dirservers.
    - Move the 'tor' binary back to /usr/local/bin/ -- it turns out
      many users don't even *have* a /usr/local/sbin/.


Changes in version 0.0.2pre21 - 2004-02-18
  o New features:
    - There's a ChangeLog file that actually reflects the changelog.
    - There's a 'torify' wrapper script, with an accompanying
      tor-tsocks.conf, that simplifies the process of using tsocks for
      tor. It even has a man page.
    - The tor binary gets installed to sbin rather than bin now.
    - Retry streams where the connected cell hasn't arrived in 15 seconds
    - Clean up exit policy handling -- get the default out of the torrc,
      so we can update it without forcing each server operator to fix
      his/her torrc.
    - Allow imaps and pop3s in default exit policy
  o Bugfixes:
    - Prevent picking middleman nodes as the last node in the circuit


Changes in version 0.0.2pre20 - 2004-01-30
  o New features:
    - We now have a deb package, and it's in debian unstable. Go to
      it, apt-getters. :)
    - I've split the TotalBandwidth option into BandwidthRate (how many
      bytes per second you want to allow, long-term) and
      BandwidthBurst (how many bytes you will allow at once before the cap
      kicks in). This better token bucket approach lets you, say, set
      BandwidthRate to 10KB/s and BandwidthBurst to 10MB, allowing good
      performance while not exceeding your monthly bandwidth quota.
    - Push out a tls record's worth of data once you've got it, rather
      than waiting until you've read everything waiting to be read. This
      may improve performance by pipelining better. We'll see.
    - Add an AP_CONN_STATE_CONNECTING state, to allow streams to detach
      from failed circuits (if they haven't been connected yet) and attach
      to new ones.
    - Expire old streams that haven't managed to connect. Some day we'll
      have them reattach to new circuits instead.

  o Bugfixes:
    - Fix several memory leaks that were causing servers to become bloated
      after a while.
    - Fix a few very rare assert triggers. A few more remain.
    - Setuid to User _before_ complaining about running as root.


Changes in version 0.0.2pre19 - 2004-01-07
  o Bugfixes:
    - Fix deadlock condition in dns farm. We were telling a child to die by
      closing the parent's file descriptor to him. But newer children were
      inheriting the open file descriptor from the parent, and since they
      weren't closing it, the socket never closed, so the child never read
      eof, so he never knew to exit. Similarly, dns workers were holding
      open other sockets, leading to all sorts of chaos.
    - New cleaner daemon() code for forking and backgrounding.
    - If you log to a file, it now prints an entry at the top of the
      logfile so you know it's working.
    - The onionskin challenge length was 30 bytes longer than necessary.
    - Started to patch up the spec so it's not quite so out of date.


Changes in version 0.0.2pre18 - 2004-01-02
  o Bugfixes:
    - Fix endian issues with the 'integrity' field in the relay header.
    - Fix a potential bug where connections in state
      AP_CONN_STATE_CIRCUIT_WAIT might unexpectedly ask to write.


Changes in version 0.0.2pre17 - 2003-12-30
  o Bugfixes:
    - Made --debuglogfile (or any second log file, actually) work.
    - Resolved an edge case in get_unique_circ_id_by_conn where a smart
      adversary could force us into an infinite loop.

  o Features:
    - Each onionskin handshake now includes a hash of the computed key,
      to prove the server's identity and help perfect forward secrecy.
    - Changed cell size from 256 to 512 bytes (working toward compatibility
      with MorphMix).
    - Changed cell length to 2 bytes, and moved it to the relay header.
    - Implemented end-to-end integrity checking for the payloads of
      relay cells.
    - Separated streamid from 'recognized' (otherwise circuits will get
      messed up when we try to have streams exit from the middle). We
      use the integrity-checking to confirm that a cell is addressed to
      this hop.
    - Randomize the initial circid and streamid values, so an adversary who
      breaks into a node can't learn how many circuits or streams have
      been made so far.


Changes in version 0.0.2pre16 - 2003-12-14
  o Bugfixes:
    - Fixed a bug that made HUP trigger an assert
    - Fixed a bug where a circuit that immediately failed wasn't being
      counted as a failed circuit in counting retries.

  o Features:
    - Now we close the circuit when we get a truncated cell: otherwise we're
      open to an anonymity attack where a bad node in the path truncates
      the circuit and then we open streams at him.
    - Add port ranges to exit policies
    - Add a conservative default exit policy
    - Warn if you're running tor as root
    - on HUP, retry OR connections and close/rebind listeners
    - options.EntryNodes: try these nodes first when picking the first node
    - options.ExitNodes: if your best choices happen to include any of
      your preferred exit nodes, you choose among just those preferred
      exit nodes.
    - options.ExcludedNodes: nodes that are never picked in path building


Changes in version 0.0.2pre15 - 2003-12-03
  o Robustness and bugfixes:
    - Sometimes clients would cache incorrect DNS resolves, which would
      really screw things up.
    - An OP that goes offline would slowly leak all its sockets and stop
      working.
    - A wide variety of bugfixes in exit node selection, exit policy
      handling, and processing pending streams when a new circuit is
      established.
    - Pick nodes for a path only from those the directory says are up
    - Choose randomly from all running dirservers, not always the first one
    - Increase allowed http header size for directory fetch.
    - Stop writing to stderr (if we're daemonized it will be closed).
    - Enable -g always, so cores will be more useful to me.
    - Switch "-lcrypto -lssl" to "-lssl -lcrypto" for broken distributions.

  o Documentation:
    - Wrote a man page. It lists commonly used options.

  o Configuration:
    - Change default loglevel to warn.
    - Make PidFile default to null rather than littering in your CWD.
    - OnionRouter config option is now obsolete. Instead it just checks
      ORPort>0.
    - Moved to a single unified torrc file for both clients and servers.


Changes in version 0.0.2pre14 - 2003-11-29
  o Robustness and bugfixes:
    - Force the admin to make the DataDirectory himself
      - to get ownership/permissions right
      - so clients no longer make a DataDirectory and then never use it
    - fix bug where a client who was offline for 45 minutes would never
      pull down a directory again
    - fix (or at least hide really well) the dns assert bug that was
      causing server crashes
    - warnings and improved robustness wrt clockskew for certs
    - use the native daemon(3) to daemonize, when available
    - exit if bind() fails
    - exit if neither socksport nor orport is defined
    - include our own tor_timegm (Win32 doesn't have its own)
    - bugfix for win32 with lots of connections
    - fix minor bias in PRNG
    - make dirserver more robust to corrupt cached directory

  o Documentation:
    - Wrote the design document (woo)

  o Circuit building and exit policies:
    - Circuits no longer try to use nodes that the directory has told them
      are down.
    - Exit policies now support bitmasks (18.0.0.0/255.0.0.0) and
      bitcounts (18.0.0.0/8).
    - Make AP connections standby for a circuit if no suitable circuit
      exists, rather than failing
    - Circuits choose exit node based on addr/port, exit policies, and
      which AP connections are standing by
    - Bump min pathlen from 2 to 3
    - Relay end cells have a payload to describe why the stream ended.
    - If the stream failed because of exit policy, try again with a new
      circuit.
    - Clients have a dns cache to remember resolved addresses.
    - Notice more quickly when we have no working circuits

  o Configuration:
    - APPort is now called SocksPort
    - SocksBindAddress, ORBindAddress, DirBindAddress let you configure
      where to bind
    - RecommendedVersions is now a config variable rather than
      hardcoded (for dirservers)
    - Reloads config on HUP
    - Usage info on -h or --help
    - If you set User and Group config vars, it'll setu/gid to them.


Changes in version 0.0.2pre13 - 2003-10-19
  o General stability:
    - SSL_write no longer fails when it returns WANTWRITE and the number
      of bytes in the buf has changed by the next SSL_write call.
    - Fix segfault fetching directory when network is down
    - Fix a variety of minor memory leaks
    - Dirservers reload the fingerprints file on HUP, so I don't have
      to take down the network when I approve a new router
    - Default server config file has explicit Address line to specify fqdn

  o Buffers:
    - Buffers grow and shrink as needed (Cut process size from 20M to 2M)
    - Make listener connections not ever alloc bufs

  o Autoconf improvements:
    - don't clobber an external CFLAGS in ./configure
    - Make install now works
    - create var/lib/tor on make install
    - autocreate a tor.sh initscript to help distribs
    - autocreate the torrc and sample-server-torrc with correct paths

  o Log files and Daemonizing now work:
    - If --DebugLogFile is specified, log to it at -l debug
    - If --LogFile is specified, use it instead of commandline
    - If --RunAsDaemon is set, tor forks and backgrounds on startup