tor-parallel-relay-conn/ChangeLog

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 Crash and assert fixes from 0.1.0.17:
    - Fix assert bug in close_logs() on exit: when we close and delete
      logs, remove them all from the global "logfiles" list.
    - 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 Peter
      Palfrader).
    - 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".
    - Setconf SocksListenAddress kills Tor if it fails to bind. Now back
      out and refuse the setconf if it would fail.
    - If you specify a relative torrc path and you set RunAsDaemon in
      your torrc, then it chdir()'s to the new directory. If you then
      HUP, it tries to load the new torrc location, fails, and exits.
      The fix: no longer allow a relative path to torrc when using -f.
    - Check for integer overflows in more places, when adding elements
      to smartlists. This could possibly prevent a buffer overflow
      on malicious huge inputs.

  o Security fixes, major:
    - When we're printing strings from the network, don't try to print
      non-printable characters. Now we're safer against shell escape
      sequence exploits, and also against attacks to fool users into
      misreading their logs.
    - 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.
      Fixes CVE-2006-0414.
    - 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.
    - Obey our firewall options more faithfully:
      . 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.
    - Make clients regenerate their keys when their IP address changes.
    - For the OS X package's modified privoxy config file, comment
      out the "logfile" line so we don't log everything passed
      through privoxy.
    - Our TLS handshakes were generating a single public/private
      keypair for the TLS context, rather than making a new one for
      each new connection. 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. Now we are.
    - Require server descriptors to list IPv4 addresses -- hostnames
      are no longer allowed. This also fixes potential vulnerabilities
      to servers providing hostnames as their address and then
      preferentially resolving them so they can partition users.
    - Our logic to decide if the OR we connected to was the right guy
      was brittle and maybe open to a mitm for invalid routers.

  o Security fixes, minor:
    - Adjust tor-spec.txt to parameterize cell and key lengths. Now
      Ian Goldberg can prove things about our handshake protocol more
      easily.
    - Make directory authorities generate a separate "guard" flag to
      mean "would make a good entry guard". Clients now honor the
      is_guard flag rather than looking at is_fast or is_stable.
    - Try to list MyFamily elements by key, not by nickname, and warn
      if we've not heard of a server.
    - Start using RAND_bytes rather than RAND_pseudo_bytes from
      OpenSSL. Also, reseed our entropy every hour, not just at
      startup. And add entropy in 512-bit chunks, not 160-bit chunks.
    - Refuse server descriptors where 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 that cell.
    - 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.
    - Fix a possible way to DoS dirservers.
    - 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.

  o Packaging improvements:
    - Implement --with-libevent-dir option to ./configure. Improve
      search techniques to find libevent, and use those for openssl too.
    - Fix a couple of bugs in OpenSSL detection. Deal better when
      there are multiple SSLs installed with different versions.
    - Avoid warnings about machine/limits.h on Debian GNU/kFreeBSD.
    - On non-gcc compilers (e.g. Solaris's cc), use "-g -O" instead of
      "-Wall -g -O2".
    - Make unit tests (and other invocations that aren't the real Tor)
      run without launching listeners, creating subdirectories, and so on.
    - The OS X installer was adding a symlink for tor_resolve but
      the binary was called tor-resolve (reported by Thomas Hardly).
    - Now we can target arch and OS in rpm builds (contributed by
      Phobos). Also make the resulting dist-rpm filename match the
      target arch.
    - Apply Matt Ghali's --with-syslog-facility patch to ./configure
      if you log to syslog and want something other than LOG_DAEMON.
    - Fix the torify (tsocks) config file to not use Tor for localhost
      connections.
    - Start shipping socks-extensions.txt, tor-doc-unix.html,
      tor-doc-server.html, and stylesheet.css in the tarball.
    - Stop shipping tor-doc.html, INSTALL, and README in the tarball.
      They are useless now.
    - Add Peter Palfrader's contributed check-tor script. It lets you
      easily check whether a given server (referenced by nickname)
      is reachable by you.
    - Add BSD-style contributed startup script "rc.subr" from Peter
      Thoenen.

  o Directory improvements -- new directory protocol:
    - See tor/doc/dir-spec.txt for all the juicy details. Key points:
    - Authorities and caches publish individual descriptors (by
      digest, by fingerprint, by "all", and by "tell me yours").
    - Clients don't download or use the old directory anymore. Now they
      download network-statuses from the directory authorities, and
      fetch individual server descriptors as needed from mirrors.
    - Clients don't download descriptors of non-running servers.
    - Download descriptors by 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.
    - Only upload a new server descriptor when options change, 18
      hours have passed, uptime is reset, or bandwidth changes a lot.
    - Directory authorities 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.)
    - 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 the first set of descriptors.
    - When picking a random directory, prefer non-authorities if any
      are known.
    - Add a new flag to network-status indicating whether the server
      can answer v2 directory requests too.
    - Directory mirrors now cache up to 16 unrecognized network-status
      docs, so new directory authorities will be cached too.
    - Stop parsing, storing, or using running-routers output (but
      mirrors still cache and serve it).
    - Clients consider a threshold of "versioning" directory authorities
      before deciding whether to warn the user that he's obsolete.
    - Authorities publish separate sorted lists of recommended versions
      for clients and for servers.
    - Change DirServers config line to note which dirs are v1 authorities.
    - Put nicknames on the DirServer line, so we can refer to them
      without requiring all our users to memorize their IP addresses.
    - 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.
    - Stop listing down or invalid nodes in the v1 directory. This
      reduces its bulk by about 1/3, and reduces load on mirrors.
    - Mirrors no longer cache the v1 directory as often.
    - If we as a directory mirror don't know of any v1 directory
      authorities, then don't try to cache any v1 directories.

  o Other directory improvements:
    - Add lefkada.eecs.harvard.edu and tor.dizum.com as fourth and
      fifth authoritative directory servers.
    - Directory authorities no longer require an open connection from
      a server to consider him "reachable". We need this change because
      when we add new directory authorities, old servers won't know not
      to hang up on them.
    - Dir authorities now do their own external reachability testing
      of each server, and only list as running the ones they 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.
    - Spread the directory authorities' reachability testing over the
      entire testing interval, so we don't try to do 500 TLS's at once
      every 20 minutes.
    - 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.
    - 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.
    - 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).
    - Return a robots.txt on our dirport to discourage google indexing.

  o Controller protocol improvements:
    - Revised controller protocol (version 1) that uses ascii rather
      than binary: tor/doc/control-spec.txt. Add supporting libraries
      in python and java and c# so you can use the controller from your
      applications without caring how our protocol works.
    - Allow the DEBUG controller event to work again. Mark certain log
      entries as "don't tell this to controllers", so we avoid cycles.
    - New controller function "getinfo accounting", to ask how
      many bytes we've used in this time period.
    - 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. Also
      expose guard nodes, config options/names.
    - Add a "quit" command (when when using the controller manually).
    - Add a new signal "newnym" 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. This also occurs on HUP
      or "signal reload".
    - 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.
    - Add a new controller event type "authdir_newdescs" that allows
      controllers to get all server descriptors that were uploaded to
      a router in its role as directory authority.
    - New controller option "getinfo desc/all-recent" to fetch the
      latest server descriptor for every router that Tor knows about.
    - 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.
    - 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.
    - 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.
    - Let the controller ask for "getinfo dir/server/foo" so it can ask
      directly rather than connecting to the dir port. "getinfo
      dir/status/foo" also works, but currently only if your DirPort
      is enabled.
    - 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.
    - If the controller's *setconf commands fail, collect an error
      message in a string and hand it back to the controller -- don't
      just tell them to go read their logs.

  o Scalability, resource management, and performance:
    - Fix a major load balance bug: we were round-robin reading 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.
    - 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 ever or b) our capacity is low
      and we're using a default DirPort.
    - 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.
    - Compress exit policies even more: look for duplicate lines and
      remove them.
    - 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.
    - 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.
    - Reduce memory requirements in our structs by changing the order
      of fields. Replace balanced trees with hash tables. Inline
      bottleneck smartlist functions. Add a "Map from digest to void*"
      abstraction so we can do less hex encoding/decoding, and use it
      in router_get_by_digest(). Many other CPU and memory improvements.
    - 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
      purpose is 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.)
    - Stop doing the complex voodoo overkill checking for insecure
      Diffie-Hellman keys. Just check if it's in [2,p-2] and be happy.
    - Do round-robin writes for TLS of at most 16 kB per write. This
      might be more fair on loaded Tor servers.
    - 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.

  o Other bugfixes and improvements:
    - Start storing useful information to $DATADIR/state, so we can
      remember things across invocations of Tor. Retain unrecognized
      lines so we can be forward-compatible, and write a TorVersion line
      so we can be backward-compatible.
    - If ORPort is set, 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 guess their address.
    - Regenerate our local descriptor if it's dirty and we try to use
      it locally (e.g. if it changes during reachability detection).
      This was causing some Tor servers to keep publishing the same
      initial descriptor forever.
    - 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.
    - 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 authorities 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.
    - Newly bootstrapped Tor networks couldn't establish hidden service
      circuits until they had nodes with high uptime. Be more tolerant.
    - 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.
    - When we fail to bind or listen on an incoming or outgoing
      socket, we now close it before refusing, rather than just
      leaking it. (Thanks to Peter Palfrader for finding.)
    - Fix a file descriptor 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.
    - Workaround a problem with some http proxies that refuse GET
      requests that specify "Content-Length: 0". Reported by Adrian.
    - 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.
    - 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.
    - Check for even more Windows version flags when writing the platform
      string in server descriptors, and note any we don't recognize.
    - Add reasons to DESTROY and RELAY_TRUNCATED cells, so clients can
      get a better idea of why their circuits failed. Not used yet.
    - 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.
    - Let people type "tor --install" as well as "tor -install" when they
      want to make it an NT service.
    - Looks like we were never delivering deflated (i.e. compressed)
      running-routers lists, even when asked. Oops.
    - We were leaking some memory every time the client changed IPs.
    - Clean up more of the OpenSSL memory when exiting, so we can detect
      memory leaks better.
    - Never call free() on tor_malloc()d memory. This will help us
      use dmalloc to detect memory leaks.
    - Some Tor servers process billions of cells per day. These
      statistics are now uint64_t's.
    - 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.
    - Fix minor integer overflow in calculating when we expect to use up
      our bandwidth allocation before hibernating.
    - 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.
    - Stop writing the "router.desc" file, ever. Nothing uses it anymore,
      and its existence is confusing some users.

  o Config option fixes:
    - Add a new config option ExitPolicyRejectPrivate which defaults
      to on. Now all exit policies will begin with rejecting private
      addresses, unless the server operator explicitly turns it off.
    - Bump the default bandwidthrate to 3 MB, and burst to 6 MB.
    - Add new ReachableORAddresses and ReachableDirAddresses options
      that understand address policies. FascistFirewall is now a synonym
      for "ReachableORAddresses *:443", "ReachableDirAddresses *:80".
    - Start calling it FooListenAddress rather than FooBindAddress,
      since few of our users know what it means to bind an address
      or port.
    - 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.
    - 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 ignore the 6668.
    - 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.
    - Setconf was appending items to linelists, not clearing them.
    - Add MyFamily to torrc.sample in the server section, so operators
      will be more likely to learn that it exists.
    - Make ContactInfo mandatory for authoritative directory servers.
    - 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.
    - 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.
    - Correct the man page entry on TrackHostExitsExpire.
    - Let directory authorities start even if they don't specify an
      Address config option.
    - Change "AllowUnverifiedNodes" to "AllowInvalidNodes", to
      reflect the updated flags in our v2 dir protocol.

  o Config option features:
    - 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.
    - 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.
    - 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).
    - Add "HardwareAccel" config option: support for crypto hardware
      accelerators via OpenSSL. 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.)
    - New config option "AuthDirRejectUnlisted" for directory authorities
      as a panic button: if we get flooded with unusable servers we can
      revert to only listing servers in the approved-routers file.
    - Directory authorities can now reject/invalidate by key and IP,
      with the config options "AuthDirInvalid" and "AuthDirReject", or
      by marking a fingerprint as "!reject" or "!invalid" (as its
      nickname) in the approved-routers file. This is useful since
      currently we automatically list servers as running and usable
      even if we know they're jerks.
    - Add a new config option TestSocks so people can see whether their
      applications are using socks4, socks4a, socks5-with-ip, or
      socks5-with-fqdn. This way they don't have to keep mucking
      with tcpdump and wondering if something got cached somewhere.
    - 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.
    - Accept "private:*" in routerdesc exit policies; not generated yet
      because older Tors do not understand it.
    - Add configuration option "V1AuthoritativeDirectory 1" which
      moria1, moria2, and tor26 have set.
    - 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.
    - 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.
    - 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.
    - New config option SafeSocks to reject all application connections
      using unsafe socks protocols. Defaults to off.

  o Improved and clearer log messages:
    - 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.
    - Log server fingerprint on startup, so new server operators don't
      have to go hunting around their filesystem for it.
    - Provide dire warnings to any users who set DirServer manually;
      move it out of torrc.sample and into torrc.complete.
    - Make the log message less scary when all the dirservers are
      temporarily unreachable.
    - When tor_socketpair() fails in Windows, give a reasonable
      Windows-style errno back.
    - Improve tor_gettimeofday() granularity on windows.
    - We were printing the number of idle dns workers incorrectly when
      culling them.
    - Handle duplicate lines in approved-routers files without warning.
    - We were whining about using socks4 or socks5-with-local-lookup
      even when it's an IP address in the "virtual" range we designed
      exactly for this case.
    - Check for named servers when looking them up by nickname;
      warn when we're calling a non-named server by its nickname;
      don't warn twice about the same name.
    - Downgrade the dirserver log messages when whining about
      unreachability.
    - Correct "your server is reachable" log entries to indicate that
      it was self-testing that told us so.
    - If we're trying to be a Tor server and running Windows 95/98/ME
      as a server, explain that we'll likely crash.
    - 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?"
    - Only start testing reachability once we've established a
      circuit. This will make startup on dir authorities less noisy.
    - Don't try to upload hidden service descriptors until we have
      established a circuit.
    - Tor didn't warn when it failed to open a log file.
    - Warn when listening on a public address for socks. We 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.
    - Give a useful message when people run Tor as the wrong user,
      rather than telling them to start chowning random directories.
    - 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."
    - Fix wrong log message when you add a "HiddenServiceNodes" config
      line without any HiddenServiceDir line (reported by Chris Thomas).
    - Directory authorities 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.
    - When logging via syslog, include the pid whenever we provide
      a log entry. Suggested by Todd Fries.
    - 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.
    - 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.
    - NT service patch from Matt Edman to improve error messages on Win32.


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 0.1.0.16 - 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.
    - One of the dirservers (tor26) changed its IP address.
    - 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 0.1.0.15 - 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 0.1.0.14 - 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 0.1.0.13 - 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 0.1.0.12 - 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 0.1.0.11 - 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 0.1.0.10 - 2005-06-14
  o Fixes on Win32:
    - Make NT services work and start on startup on Win32 (based on
      patch by Matt Edman). See the FAQ entry for details.
    - Make 'platform' string in descriptor more accurate for Win32
      servers, so it's not just "unknown platform".
    - REUSEADDR on normal platforms means you can rebind to the port
      right after somebody else has let it go. But REUSEADDR on Win32
      means you can bind to the port _even when somebody else already
      has it bound_! So, don't do that on Win32.
    - Clean up the log messages when starting on Win32 with no config
      file.
    - Allow seeding the RNG on Win32 even when you're not running as
      Administrator. If seeding the RNG on Win32 fails, quit.

  o Assert / crash bugs:
    - 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).
    - 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.
    - Fix a race condition that can trigger an assert when we have a
      pending create cell and an OR connection attempt fails.

  o Resource leaks:
    - Use pthreads for worker processes rather than forking. 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.
      - Implement --disable-threads configure option. Disable threads on
        netbsd and openbsd by default, because they have no reentrant
        resolver functions (!), and on solaris since it has other
        threading issues.
    - Fix possible bug on threading platforms (e.g. win32) which was
      leaking a file descriptor whenever a cpuworker or dnsworker died.
    - Fix a minor memory leak when somebody establishes an introduction
      point at your Tor server.
    - Fix possible memory leak in tor_lookup_hostname(). (Thanks to
      Adam Langley.)
    - Add ./configure --with-dmalloc option, to track memory leaks.
    - And try to free all memory on closing, so we can detect what
      we're leaking.

  o Protocol correctness:
    - 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.
    - 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.
    - 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.
    - 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.
    - Client now retries when streams end early for 'hibernating' or
      'resource limit' reasons, rather than failing them.
    - Try to be more zealous about calling connection_edge_end when
      things go bad with edge conns in connection.c.

  o Robustness improvements:
    - Better handling for heterogeneous / unreliable nodes:
      - Annotate circuits with 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 we 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: keep track of what destination ports
      we've used recently (start out assuming we'll want to use 80), and
      make sure to have enough circs around to satisfy these ports. 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).
    - 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.
    - When a client asks us for a dir mirror and we don't have one,
      launch an attempt to get a fresh one.
    - 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.

  o 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 at least ORPort is reachable (when
      DirPort is not yet found reachable, publish it as zero).
    - When building testing circs for ORPort testing, use only
      high-bandwidth nodes, so fewer circuits fail.
    - Notice when our IP changes, and reset stats/uptime/reachability.
    - Authdirservers don'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.
    - Authdirservers now automatically approve nodes running 0.1.0.2-rc
      or later.

  o Dirserver fixes:
    - 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).
    - 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.

  o Efficiency improvements:
    - Use libevent. Now we can use faster async cores (like epoll, kpoll,
      and /dev/poll), and hopefully work better on Windows too.
      - Apple's OS X 10.4.0 ships with a broken kqueue API, and using
        kqueue on 10.3.9 causes kernel panics. Don't use kqueue on OS X.
      - 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.
    - 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.
    - Switch our internal buffers implementation to use a ring buffer,
      to hopefully improve performance for fast servers a lot.
    - 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.
    - Improve performance for dirservers: stop re-parsing the whole
      directory every time you regenerate it.
    - 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 when you first see them.

  o Hidden services:
    - Handle unavailable hidden services better. Handle slow or busy
      hidden services better.
    - 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
      after fetching the descriptor, rather than for n (where n=3)
      attempts to build a circuit.
    - Adjust maximum skew and age for rendezvous descriptors: let skew
      be 48 hours rather than 90 minutes.
    - Reject malformed .onion addresses rather then passing them on as
      normal web requests.

  o Controller:
    - More Tor controller support. 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.
    - Encode hashed controller passwords in hex instead of base64,
      to make it easier to write controllers.
    - Revise control spec and implementation to allow all log messages to
      be sent to controller with their severities intact (suggested by
      Matt Edman). Disable debug-level logs while delivering a debug-level
      log to the controller, to prevent loop. Update TorControl to handle
      new log event types.

  o New config options/defaults:
    - Begin scrubbing sensitive strings from logs by default. Turn off
      the config option SafeLogging if you need to do debugging.
    - New exit policy: accept most low-numbered ports, rather than
      rejecting most low-numbered ports.
    - Put a note in the torrc about abuse potential with the default
      exit policy.
    - Add support for CONNECTing through https proxies, with "HttpsProxy"
      config option.
    - Add HttpProxyAuthenticator and HttpsProxyAuthenticator support
      based on patch from Adam Langley (basic auth only).
    - Bump the default BandwidthRate from 1 MB to 2 MB, to accommodate
      the fast servers that have been joining lately. (Clients are now
      willing to load balance over up to 2 MB of advertised bandwidth
      capacity too.)
    - 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.
    - Require BandwidthRate to be at least 20kB/s for servers.
    - 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.
    - 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 from Mike Perry).
    - 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.
    - Change compiled-in SHUTDOWN_WAIT_LENGTH from a fixed 30 secs to
      a config option "ShutdownWaitLength" (when using kill -INT on
      servers).
    - Fix an edge case in parsing config options: if they say "--"
      on the commandline, it's not a config option (thanks weasel).
    - New config option DirAllowPrivateAddresses for authdirservers.
      Now by default they refuse router descriptors that have non-IP or
      private-IP addresses.
    - Change DirFetchPeriod/StatusFetchPeriod to have a special "Be
      smart" default value: low for servers and high for clients.
    - 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.
    - Implement --verify-config command-line option to check if your torrc
      is valid without actually launching Tor.

  o Logging improvements:
    - When dirservers refuse a server descriptor, we now log its
      contactinfo, platform, and the poster's IP address.
    - 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.
    - 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.
    - Whine at you if you're a server and you don't set your contactinfo.
    - Warn when exit policy implicitly allows local addresses.
    - Give a better warning when some other server advertises an
      ORPort that is actually an apache running ssl.
    - 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.
    - When a dirserver causes you to give a warn, mention which dirserver
      it was.
    - 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.
    - Stop warning about sigpipes in the logs. We're going to
      pretend that getting these occassionally is normal and fine.

  o New contrib scripts:
    - New experimental script tor/contrib/exitlist: a simple python
      script to parse directories and find Tor nodes that exit to listed
      addresses/ports.
    - 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"
    - New contributed script "privoxy-tor-toggle" to toggle whether
      Privoxy uses Tor. Seems to be configured for Debian by default.
    - Have torctl.in/tor.sh.in check for location of su binary (needed
      on FreeBSD)

  o Misc bugfixes:
    - 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.
    - 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.
    - Stop most cases of hanging up on a socks connection without sending
      the socks reject.
    - Fix a bug in the RPM package: set home directory for _tor to
      something more reasonable when first installing.
    - Stop putting nodename in the Platform string in server descriptors.
      It doesn't actually help, and it is confusing/upsetting some people.
    - When using preferred entry or exit nodes, ignore whether the
      circuit wants uptime or capacity. They asked for the nodes, they
      get the nodes.
    - Tie MAX_DIR_SIZE to MAX_BUF_SIZE, so now directory sizes won't get
      artificially capped at 500kB.
    - Cache local dns resolves correctly even when they're .exit
      addresses.
    - If we're hibernating and we get a SIGINT, exit immediately.
    - tor-resolve requests were ignoring .exit if there was a working circuit
      they could use instead.
    - Pay more attention to the ClientOnly config option.
    - 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.

  o Misc features:
    - Rewrite address "serifos.exit" to "externalIP.serifos.exit"
      rather than just rejecting it.
    - 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.
    - 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.
    - 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.
    - Report HTTP reasons to client when getting a response from directory
      servers -- so you can actually know what went wrong.
    - 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.
    - Stop publishing socksport in the directory, since it's not
      actually meant to be public. For compatibility, publish a 0 there
      for now.
    - 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.)
    - Add OSX uninstall instructions. An actual uninstall script will
      come later.
    - Add "opt hibernating 1" to server descriptor to make it clearer
      whether the server is hibernating.


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 0.0.9.9 - 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 0.0.9.8 - 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 0.0.9.7 - 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 0.0.9.6 - 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 Bugfixes on 0.0.8.1 (Crashes and asserts):
    - Catch and ignore SIGXFSZ signals when log files exceed 2GB; our
      write() call will fail and we handle it there.
    - When we run out of disk space, or other log writing error, don't
      crash. Just stop logging to that log and continue.
    - Fix isspace() and friends so they still make Solaris happy
      but also so they don't trigger asserts on win32.
    - Fix assert failure on malformed socks4a requests.
    - Fix an assert bug where a hidden service provider would fail if
      the first hop of his rendezvous circuit was down.
    - Better handling of size_t vs int, so we're more robust on 64
      bit platforms.

  o Bugfixes on 0.0.8.1 (Win32):
    - Make windows sockets actually non-blocking (oops), and handle
      win32 socket errors better.
    - Fix parse_iso_time on platforms without strptime (eg win32).
    - win32: when being multithreaded, leave parent fdarray open.
    - Better handling of winsock includes on non-MSV win32 compilers.
    - Change our file IO stuff (especially wrt OpenSSL) so win32 is
      happier.
    - Make unit tests work on win32.

  o Bugfixes on 0.0.8.1 (Path selection and streams):
    - 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.
    - 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.
    - 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.
    - Let resolve conns retry/expire also, rather than sticking around
      forever.
    - 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.

  o Bugfixes on 0.0.8.1 (Circuits):
    - 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.
    - 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.

  o Bugfixes on 0.0.8.1 (Other):
    - Fix a whole slew of memory leaks.
    - Disallow NDEBUG. We don't ever want anybody to turn off debug.
    - If we are using select, make sure we stay within FD_SETSIZE.
    - When poll() is interrupted, we shouldn't believe the revents values.
    - Add a FAST_SMARTLIST define to optionally inline smartlist_get
      and smartlist_len, which are two major profiling offenders.
    - If do_hup fails, actually notice.
    - Flush the log file descriptor after we print "Tor opening log file",
      so we don't see those messages days later.
    - Hidden service operators now correctly handle version 1 style
      INTRODUCE1 cells (nobody generates them still, so not a critical
      bug).
    - Handle more errnos from accept() without closing the listener.
      Some OpenBSD machines were closing their listeners because
      they ran out of file descriptors.
    - 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.
    - 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.)
    - 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.
    - 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.
    - If a verified OR connects to us before he's uploaded his descriptor,
      or we verify him and hup but he still has the original TLS
      connection, then conn->nickname is still set like he's unverified.

  o Code security improvements, inspired by Ilja:
    - tor_snprintf wrapper over snprintf with consistent (though not C99)
      overflow behavior.
    - Replace sprintf with tor_snprintf. (I think they were all safe, but
      hey.)
    - Replace strcpy/strncpy with strlcpy in more places.
    - Avoid strcat; use tor_snprintf or strlcat instead.

  o Features (circuits and streams):
    - 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.)
    - Support "foo.nickname.exit" addresses, to let Alice request the
      address "foo" as viewed by exit node "nickname". Based on a patch
      from Geoff Goodell.
    - 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.
    - Refuse application socks connections to port 0.
    - Use only 0.0.9pre1 and later servers for resolve cells.

  o Features (bandwidth):
    - Hibernation: New config option "AccountingMax" lets you
      set how many bytes per month (in each direction) 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.
    - 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.

  o Features (directories):
    - New "router-status" line in directory, to better bind each verified
      nickname to its identity key.
    - 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.
    - Respond to content-encoding headers by trying to uncompress as
      appropriate.
    - Clients and servers now fetch running-routers; cache
      running-routers; compress running-routers; serve compressed
      running-routers.z
    - 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.
    - Protect dirservers from overzealous descriptor uploading -- wait
      10 seconds after directory gets dirty, before regenerating.

  o Features (packages and install):
    - Add NSI installer contributed by J Doe.
    - Apply NT service patch from Osamu Fujino. Still needs more work.
    - 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.
    - Make expand_filename handle ~ and ~username.
    - Use autoconf to enable largefile support where necessary. Use
      ftello where available, since ftell can fail at 2GB.
    - Ship src/win32/ in the tarball, so people can use it to build.
    - Make old win32 fall back to CWD if SHGetSpecialFolderLocation
      is broken.

  o Features (ui controller):
    - 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.
    - Implement the control-spec's SAVECONF command, to write your
      configuration to torrc.
    - Get cookie authentication for the controller closer to working.
    - When set_conf changes our server descriptor, upload a new copy.
      But don't upload it too often if there are frequent changes.

  o Features (config and command-line):
    - Deprecate unofficial config option abbreviations, and abbreviations
      not on the command line.
    - Configuration infrastructure support for warning on obsolete
      options.
    - Give a slightly more useful output for "tor -h".
    - Break DirFetchPostPeriod into:
      - DirFetchPeriod for fetching full directory,
      - StatusFetchPeriod for fetching running-routers,
      - DirPostPeriod for posting server descriptor,
      - RendPostPeriod for posting hidden service descriptors.
    - New log format in config:
      "Log minsev[-maxsev] stdout|stderr|syslog" or
      "Log minsev[-maxsev] file /var/foo"
    - DirPolicy config option, to let people reject incoming addresses
      from their dirserver.
    - "tor --list-fingerprint" will list your identity key fingerprint
      and then exit.
    - Make tor --version --version dump the cvs Id of every file.
    - 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.
    - Add "pass" target for RedirectExit, to make it easier to break
      out of a sequence of RedirectExit rules.
    - 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 'Routerfile' config option obsolete.
    - Discourage people from setting their dirfetchpostperiod more often
      than once per minute.

  o Features (other):
    - kill -USR2 now moves all logs to loglevel debug (kill -HUP to
      get back to normal.)
    - Accept *:706 (silc) in default exit policy.
    - Implement new versioning format for post 0.1.
    - Distinguish between TOR_TLS_CLOSE and TOR_TLS_ERROR, so we can
      log more informatively.
    - Check clock skew for verified servers, but allow unverified
      servers and clients to have any clock skew.
    - Make sure the hidden service descriptors are at a random offset
      from each other, to hinder linkability.
    - Clients now generate a TLS cert too, in preparation for having
      them act more like real nodes.
    - Add a pure-C tor-resolve implementation.
    - Use getrlimit and friends to ensure we can reach MaxConn (currently
      1024) file descriptors.
    - Raise the max dns workers from 50 to 100.


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 0.0.8 - 2004-08-25
  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.
    - 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.
    - 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.
    - Port it to SunOS 5.9 / Athena
    - Fix two bugs in saving onion keys to disk when rotating, so
      hopefully we'll get fewer people using old onion keys.
    - Remove our mostly unused -- and broken -- hex_encode()
      function. Use base16_encode() instead. (Thanks to Timo Lindfors
      for pointing out this bug.)
    - Only pick and establish intro points after we've gotten a
      directory.
    - 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.

  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.
      - AllowUnverifiedNodes config option to let circuits choose no-name
        routers in entry,middle,exit,introduction,rendezvous positions.
        Allow middle and rendezvous positions by default.
      - When picking unverified routers, skip those with low uptime and/or
        low bandwidth, depending on what properties you care about.
      - 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.
      - 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.)
    - Clients choose nodes proportional to advertised bandwidth.
    - Clients avoid using nodes with low uptime as introduction points.
    - Handle servers with dynamic IP addresses: don't just 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)
    - Try other dirservers immediately if the one you try is down. This
      should tolerate down dirservers better now.
    - 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.
    - 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.
    - 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.
    - Log a warning if the user uses an unsafe socks variant, so people
      are more likely to learn about privoxy or socat.
    - Log a warning if you're running an unverified server, to let you
      know you might want to get it verified.
    - Change the default exit policy to reject the default edonkey,
      kazaa, gnutella ports.
    - Add replace_file() to util.[ch] to handle win32's rename().
    - Publish OR uptime in descriptor (and thus in directory) too.
    - Remember used bandwidth (both in and out), and publish 15-minute
      snapshots for the past day into our descriptor.
    - 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]".


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 0.0.7.2 - 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 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.
    - Check directory signatures based on name of signer, not on whom
      we got the directory from. This will let us cache directories more
      easily.
    - Rotate dnsworkers and cpuworkers on SIGHUP, so they get new config
      settings too.
  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.
    - Updated the man page to reflect these features.


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
  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.)
    - We now rotate link (tls context) keys and onion keys.
    - CREATE cells now include oaep padding, so you can tell
      if you decrypted them correctly.
    - Retry stream correctly when we fail to connect because of
      exit-policy-reject (should try another) or can't-resolve-address.
    - 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.
    - Add bandwidthburst to server descriptor.
    - Directories now say which dirserver signed them.
    - Use a tor_assert macro that logs failed assertions too.
    - Since we don't support truncateds much, don't bother sending them;
      just close the circ.
    - Fetch randomness from /dev/urandom better (not via fopen/fread)
    - Better debugging for tls errors
    - Set Content-Type on the directory and hidserv descriptor.
    - Remove IVs from cipher code, since AES-ctr has none.
  o Bugfixes:
    - Fix an assert trigger for exit nodes that's been plaguing us since
      the days of 0.0.2prexx (thanks weasel!)
    - 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.
    - Fix a bug that's been lurking since 27 may 03 (!)
      When passing back a destroy cell, we would use the wrong circ id.
    - Don't crash if a conn that sent a begin has suddenly lost its circuit.
    - Some versions of openssl have an SSL_pending function that erroneously
      returns bytes when there is a non-application record pending.
    - 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.
      o Handle windows socket errors correctly.
  o Portability:
    - check for <sys/limits.h> so we build on FreeBSD again, and
      <machine/limits.h> for NetBSD.


Changes in version 0.0.5 - 2004-03-30
  o Install torrc as torrc.sample -- we no longer clobber your
    torrc. (Woo!)
  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.
  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
  o Add in a 'notice' log level for things the operator should hear
    but that aren't warnings


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