control-spec.txt 52 KB

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  1. $Id$
  2. TC: A Tor control protocol (Version 1)
  3. 0. Scope
  4. This document describes an implementation-specific protocol that is used
  5. for other programs (such as frontend user-interfaces) to communicate with a
  6. locally running Tor process. It is not part of the Tor onion routing
  7. protocol.
  8. This protocol replaces version 0 of TC, which is now deprecated. For
  9. reference, TC is described in "control-spec-v0.txt". Implementors are
  10. recommended to avoid using TC directly, but instead to use a library that
  11. can easily be updated to use the newer protocol. (Version 0 is used by Tor
  12. versions 0.1.0.x; the protocol in this document only works with Tor
  13. versions in the 0.1.1.x series and later.)
  14. 1. Protocol outline
  15. TC is a bidirectional message-based protocol. It assumes an underlying
  16. stream for communication between a controlling process (the "client"
  17. or "controller") and a Tor process (or "server"). The stream may be
  18. implemented via TCP, TLS-over-TCP, a Unix-domain socket, or so on,
  19. but it must provide reliable in-order delivery. For security, the
  20. stream should not be accessible by untrusted parties.
  21. In TC, the client and server send typed messages to each other over the
  22. underlying stream. The client sends "commands" and the server sends
  23. "replies".
  24. By default, all messages from the server are in response to messages from
  25. the client. Some client requests, however, will cause the server to send
  26. messages to the client indefinitely far into the future. Such
  27. "asynchronous" replies are marked as such.
  28. Servers respond to messages in the order messages are received.
  29. 2. Message format
  30. 2.1. Description format
  31. The message formats listed below use ABNF as described in RFC 2234.
  32. The protocol itself is loosely based on SMTP (see RFC 2821).
  33. We use the following nonterminals from RFC 2822: atom, qcontent
  34. We define the following general-use nonterminals:
  35. String = DQUOTE *qcontent DQUOTE
  36. There are explicitly no limits on line length. All 8-bit characters are
  37. permitted unless explicitly disallowed.
  38. 2.2. Commands from controller to Tor
  39. Command = Keyword Arguments CRLF / "+" Keyword Arguments CRLF Data
  40. Keyword = 1*ALPHA
  41. Arguments = *(SP / VCHAR)
  42. Specific commands and their arguments are described below in section 3.
  43. 2.3. Replies from Tor to the controller
  44. Reply = *(MidReplyLine / DataReplyLine) EndReplyLine
  45. MidReplyLine = "-" ReplyLine
  46. DataReplyLine = "+" ReplyLine Data
  47. EndReplyLine = SP ReplyLine
  48. ReplyLine = StatusCode [ SP ReplyText ] CRLF
  49. ReplyText = XXXX
  50. StatusCode = XXXX
  51. Specific replies are mentioned below in section 3, and described more fully
  52. in section 4.
  53. 2.4. General-use tokens
  54. ; Identifiers for servers.
  55. ServerID = Nickname / Fingerprint
  56. Nickname = 1*19 NicknameChar
  57. NicknameChar = "a"-"z" / "A"-"Z" / "0" - "9"
  58. Fingerprint = "$" 40*HEXDIG
  59. ; A "=" indicates that the given nickname is canonical; a "~" indicates
  60. ; that the given nickname is not canonical.
  61. LongName = Fingerprint [ ( "=" / "~" ) Nickname ]
  62. ; How a controller tells Tor about a particular OR. There are four
  63. ; possible formats:
  64. ; $Digest -- The router whose identity key hashes to the given digest.
  65. ; This is the preferred way to refer to an OR.
  66. ; $Digest~Name -- The router whose identity key hashes to the given
  67. ; digest, but only if the router has the given nickname.
  68. ; $Digest=Name -- The router whose identity key hashes to the given
  69. ; digest, but only if the router is Named and has the given
  70. ; nickname.
  71. ; Name -- The Named router with the given nickname, or, if no such
  72. ; router exists, any router whose nickname matches the one given.
  73. ; This is not a safe way to refer to routers, since Named status
  74. ; could under some circumstances change over time.
  75. ServerSpec = LongName / Nickname
  76. ; Unique identifiers for streams or circuits. Currently, Tor only
  77. ; uses digits, but this may change
  78. StreamID = 1*16 IDChar
  79. CircuitID = 1*16 IDChar
  80. IDChar = ALPHA / DIGIT
  81. Address = ip4-address / ip6-address / hostname (XXXX Define these)
  82. ; A "Data" section is a sequence of octets concluded by the terminating
  83. ; sequence CRLF "." CRLF. The terminating sequence may not appear in the
  84. ; body of the data. Leading periods on lines in the data are escaped with
  85. ; an additional leading period as in RFC 2821 section 4.5.2.
  86. Data = *DataLine "." CRLF
  87. DataLine = CRLF / "." 1*LineItem CRLF / NonDotItem *LineItem CRLF
  88. LineItem = NonCR / 1*CR NonCRLF
  89. NonDotItem = NonDotCR / 1*CR NonCRLF
  90. 3. Commands
  91. All commands and other keywords are case-insensitive.
  92. 3.1. SETCONF
  93. Change the value of one or more configuration variables. The syntax is:
  94. "SETCONF" 1*(SP keyword ["=" String]) CRLF
  95. Tor behaves as though it had just read each of the key-value pairs
  96. from its configuration file. Keywords with no corresponding values have
  97. their configuration values reset to 0 or NULL (use RESETCONF if you want
  98. to set it back to its default). SETCONF is all-or-nothing: if there
  99. is an error in any of the configuration settings, Tor sets none of them.
  100. Tor responds with a "250 configuration values set" reply on success.
  101. If some of the listed keywords can't be found, Tor replies with a
  102. "552 Unrecognized option" message. Otherwise, Tor responds with a
  103. "513 syntax error in configuration values" reply on syntax error, or a
  104. "553 impossible configuration setting" reply on a semantic error.
  105. When a configuration option takes multiple values, or when multiple
  106. configuration keys form a context-sensitive group (see GETCONF below), then
  107. setting _any_ of the options in a SETCONF command is taken to reset all of
  108. the others. For example, if two ORBindAddress values are configured, and a
  109. SETCONF command arrives containing a single ORBindAddress value, the new
  110. command's value replaces the two old values.
  111. 3.2. RESETCONF
  112. Remove all settings for a given configuration option entirely, assign
  113. its default value (if any), and then assign the String provided.
  114. Typically the String is left empty, to simply set an option back to
  115. its default. The syntax is:
  116. "RESETCONF" 1*(SP keyword ["=" String]) CRLF
  117. Otherwise it behaves like SETCONF above.
  118. 3.3. GETCONF
  119. Request the value of a configuration variable. The syntax is:
  120. "GETCONF" 1*(SP keyword) CRLF
  121. If all of the listed keywords exist in the Tor configuration, Tor replies
  122. with a series of reply lines of the form:
  123. 250 keyword=value
  124. If any option is set to a 'default' value semantically different from an
  125. empty string, Tor may reply with a reply line of the form:
  126. 250 keyword
  127. If some of the listed keywords can't be found, Tor replies with a
  128. "552 unknown configuration keyword" message.
  129. If an option appears multiple times in the configuration, all of its
  130. key-value pairs are returned in order.
  131. Some options are context-sensitive, and depend on other options with
  132. different keywords. These cannot be fetched directly. Currently there
  133. is only one such option: clients should use the "HiddenServiceOptions"
  134. virtual keyword to get all HiddenServiceDir, HiddenServicePort,
  135. HiddenServiceNodes, and HiddenServiceExcludeNodes option settings.
  136. 3.4. SETEVENTS
  137. Request the server to inform the client about interesting events. The
  138. syntax is:
  139. "SETEVENTS" [SP "EXTENDED"] *(SP EventCode) CRLF
  140. EventCode = "CIRC" / "STREAM" / "ORCONN" / "BW" / "DEBUG" /
  141. "INFO" / "NOTICE" / "WARN" / "ERR" / "NEWDESC" / "ADDRMAP" /
  142. "AUTHDIR_NEWDESCS" / "DESCCHANGED" / "STATUS_GENERAL" /
  143. "STATUS_CLIENT" / "STATUS_SERVER" / "GUARDS" / "NS"
  144. Any events *not* listed in the SETEVENTS line are turned off; thus, sending
  145. SETEVENTS with an empty body turns off all event reporting.
  146. The server responds with a "250 OK" reply on success, and a "552
  147. Unrecognized event" reply if one of the event codes isn't recognized. (On
  148. error, the list of active event codes isn't changed.)
  149. If the flag string "EXTENDED" is provided, Tor may provide extra
  150. information with events for this connection; see 4.1 for more information.
  151. NOTE: All events on a given connection will be provided in extended format,
  152. or none.
  153. NOTE: "EXTENDED" is only supported in Tor 0.1.1.9-alpha or later.
  154. Each event is described in more detail in Section 4.1.
  155. 3.5. AUTHENTICATE
  156. Sent from the client to the server. The syntax is:
  157. "AUTHENTICATE" [ SP 1*HEXDIG / QuotedString ] CRLF
  158. The server responds with "250 OK" on success or "515 Bad authentication" if
  159. the authentication cookie is incorrect.
  160. The format of the 'cookie' is implementation-dependent; see 5.1 below for
  161. information on how the standard Tor implementation handles it.
  162. If Tor requires authentication and the controller has not yet sent an
  163. AUTHENTICATE message, Tor sends a "514 authentication required" reply to
  164. any other kind of message.
  165. 3.6. SAVECONF
  166. Sent from the client to the server. The syntax is:
  167. "SAVECONF" CRLF
  168. Instructs the server to write out its config options into its torrc. Server
  169. returns "250 OK" if successful, or "551 Unable to write configuration
  170. to disk" if it can't write the file or some other error occurs.
  171. 3.7. SIGNAL
  172. Sent from the client to the server. The syntax is:
  173. "SIGNAL" SP Signal CRLF
  174. Signal = "RELOAD" / "SHUTDOWN" / "DUMP" / "DEBUG" / "HALT" /
  175. "HUP" / "INT" / "USR1" / "USR2" / "TERM" / "NEWNYM" /
  176. "CLEARDNSCACHE"
  177. The meaning of the signals are:
  178. RELOAD -- Reload: reload config items, refetch directory. (like HUP)
  179. SHUTDOWN -- Controlled shutdown: if server is an OP, exit immediately.
  180. If it's an OR, close listeners and exit after 30 seconds.
  181. (like INT)
  182. DUMP -- Dump stats: log information about open connections and
  183. circuits. (like USR1)
  184. DEBUG -- Debug: switch all open logs to loglevel debug. (like USR2)
  185. HALT -- Immediate shutdown: clean up and exit now. (like TERM)
  186. CLEARDNSCACHE -- Forget the client-side cached IPs for all hostnames.
  187. NEWNYM -- Switch to clean circuits, so new application requests
  188. don't share any circuits with old ones. Also clears
  189. the client-side DNS cache.
  190. The server responds with "250 OK" if the signal is recognized (or simply
  191. closes the socket if it was asked to close immediately), or "552
  192. Unrecognized signal" if the signal is unrecognized.
  193. 3.8. MAPADDRESS
  194. Sent from the client to the server. The syntax is:
  195. "MAPADDRESS" 1*(Address "=" Address SP) CRLF
  196. The first address in each pair is an "original" address; the second is a
  197. "replacement" address. The client sends this message to the server in
  198. order to tell it that future SOCKS requests for connections to the original
  199. address should be replaced with connections to the specified replacement
  200. address. If the addresses are well-formed, and the server is able to
  201. fulfill the request, the server replies with a 250 message:
  202. 250-OldAddress1=NewAddress1
  203. 250 OldAddress2=NewAddress2
  204. containing the source and destination addresses. If request is
  205. malformed, the server replies with "512 syntax error in command
  206. argument". If the server can't fulfill the request, it replies with
  207. "451 resource exhausted".
  208. The client may decline to provide a body for the original address, and
  209. instead send a special null address ("0.0.0.0" for IPv4, "::0" for IPv6, or
  210. "." for hostname), signifying that the server should choose the original
  211. address itself, and return that address in the reply. The server
  212. should ensure that it returns an element of address space that is unlikely
  213. to be in actual use. If there is already an address mapped to the
  214. destination address, the server may reuse that mapping.
  215. If the original address is already mapped to a different address, the old
  216. mapping is removed. If the original address and the destination address
  217. are the same, the server removes any mapping in place for the original
  218. address.
  219. Example:
  220. C: MAPADDRESS 0.0.0.0=tor.eff.org 1.2.3.4=tor.freehaven.net
  221. S: 250-127.192.10.10=tor.eff.org
  222. S: 250 1.2.3.4=tor.freehaven.net
  223. {Note: This feature is designed to be used to help Tor-ify applications
  224. that need to use SOCKS4 or hostname-less SOCKS5. There are three
  225. approaches to doing this:
  226. 1. Somehow make them use SOCKS4a or SOCKS5-with-hostnames instead.
  227. 2. Use tor-resolve (or another interface to Tor's resolve-over-SOCKS
  228. feature) to resolve the hostname remotely. This doesn't work
  229. with special addresses like x.onion or x.y.exit.
  230. 3. Use MAPADDRESS to map an IP address to the desired hostname, and then
  231. arrange to fool the application into thinking that the hostname
  232. has resolved to that IP.
  233. This functionality is designed to help implement the 3rd approach.}
  234. Mappings set by the controller last until the Tor process exits:
  235. they never expire. If the controller wants the mapping to last only
  236. a certain time, then it must explicitly un-map the address when that
  237. time has elapsed.
  238. 3.9. GETINFO
  239. Sent from the client to the server. The syntax is as for GETCONF:
  240. "GETINFO" 1*(SP keyword) CRLF
  241. one or more NL-terminated strings. The server replies with an INFOVALUE
  242. message, or a 551 or 552 error.
  243. Unlike GETCONF, this message is used for data that are not stored in the Tor
  244. configuration file, and that may be longer than a single line. On success,
  245. one ReplyLine is sent for each requested value, followed by a final 250 OK
  246. ReplyLine. If a value fits on a single line, the format is:
  247. 250-keyword=value
  248. If a value must be split over multiple lines, the format is:
  249. 250+keyword=
  250. value
  251. .
  252. Recognized keys and their values include:
  253. "version" -- The version of the server's software, including the name
  254. of the software. (example: "Tor 0.0.9.4")
  255. "config-file" -- The location of Tor's configuration file ("torrc").
  256. ["exit-policy/prepend" -- The default exit policy lines that Tor will
  257. *prepend* to the ExitPolicy config option.
  258. -- Never implemented. Useful?]
  259. "exit-policy/default" -- The default exit policy lines that Tor will
  260. *append* to the ExitPolicy config option.
  261. "desc/id/<OR identity>" or "desc/name/<OR nickname>" -- the latest
  262. server descriptor for a given OR, NUL-terminated.
  263. "ns/id/<OR identity>" or "ns/name/<OR nickname>" -- the latest network
  264. status info for a given OR. Network status info is as given in
  265. dir-spec.txt, and reflects the current beliefs of this Tor about the
  266. router in question. Like directory clients, controllers MUST
  267. tolerate unrecognized flags and lines. The published date and
  268. descriptor digest are those believed to be best by this Tor,
  269. not necessarily those for a descriptor that Tor currently has.
  270. [First implemented in 0.1.2.3-alpha.]
  271. "ns/all" -- Network status info for all ORs we have an opinion about,
  272. joined by newlines. [First implemented in 0.1.2.3-alpha.]
  273. "desc/all-recent" -- the latest server descriptor for every router that
  274. Tor knows about.
  275. "network-status" -- a space-separated list of all known OR identities.
  276. This is in the same format as the router-status line in directories;
  277. see dir-spec-v1.txt section 3 for details. (If VERBOSE_NAMES is
  278. enabled, the output will not conform to dir-spec-v1.txt; instead, the
  279. result will be a space-separated list of LongName, each preceded by a
  280. "!" if it is believed to be not running.)
  281. "addr-mappings/all"
  282. "addr-mappings/config"
  283. "addr-mappings/cache"
  284. "addr-mappings/control" -- a space-separated list of address
  285. mappings, each in the form of "from-address=to-address".
  286. The 'config' key returns those address mappings set in the
  287. configuration; the 'cache' key returns the mappings in the
  288. client-side DNS cache; the 'control' key returns the mappings set
  289. via the control interface; the 'all' target returns the mappings
  290. set through any mechanism.
  291. "address" -- the best guess at our external IP address. If we
  292. have no guess, return a 551 error. (Added in 0.1.2.2-alpha)
  293. "fingerprint" -- the contents of the fingerprint file that Tor
  294. writes as a server, or a 551 if we're not a server currently.
  295. (Added in 0.1.2.3-alpha)
  296. "circuit-status"
  297. A series of lines as for a circuit status event. Each line is of
  298. the form:
  299. CircuitID SP CircStatus [SP Path] CRLF
  300. "stream-status"
  301. A series of lines as for a stream status event. Each is of the form:
  302. StreamID SP StreamStatus SP CircID SP Target CRLF
  303. "orconn-status"
  304. A series of lines as for an OR connection status event. Each is of the
  305. form:
  306. ServerID SP ORStatus CRLF
  307. "entry-guards"
  308. A series of lines listing the currently chosen entry guards, if any.
  309. Each is of the form:
  310. ServerID SP (Status-with-time / Status) CRLF
  311. Status-with-time = ("down" / "unlisted") SP ISOTime
  312. Status = ("up" / "never-connected")
  313. [From 0.1.1.4-alpha to 0.1.1.10-alpha, this was called "helper-nodes".
  314. Tor still supports calling it that for now, but support will be
  315. removed in 0.1.3.x.]
  316. "accounting/enabled"
  317. "accounting/hibernating"
  318. "accounting/bytes"
  319. "accounting/bytes-left"
  320. "accounting/interval-start"
  321. "accounting/interval-wake"
  322. "accounting/interval-end"
  323. Information about accounting status. If accounting is enabled,
  324. "enabled" is 1; otherwise it is 0. The "hibernating" field is "hard"
  325. if we are accepting no data; "soft" if we're accepting no new
  326. connections, and "awake" if we're not hibernating at all. The "bytes"
  327. and "bytes-left" fields contain (read-bytes SP write-bytes), for the
  328. start and the rest of the interval respectively. The 'interval-start'
  329. and 'interval-end' fields are the borders of the current interval; the
  330. 'interval-wake' field is the time within the current interval (if any)
  331. where we plan[ned] to start being active.
  332. "config/names"
  333. A series of lines listing the available configuration options. Each is
  334. of the form:
  335. OptionName SP OptionType [ SP Documentation ] CRLF
  336. OptionName = Keyword
  337. OptionType = "Integer" / "TimeInterval" / "DataSize" / "Float" /
  338. "Boolean" / "Time" / "CommaList" / "Dependant" / "Virtual" /
  339. "String" / "LineList"
  340. Documentation = Text
  341. "info/names"
  342. A series of lines listing the available GETINFO options. Each is of
  343. one of these forms:
  344. OptionName SP Documentation CRLF
  345. OptionPrefix SP Documentation CRLF
  346. OptionPrefix = OptionName "/*"
  347. "events/names"
  348. A space-separated list of all the events supported by this version of
  349. Tor's SETEVENTS.
  350. "features/names"
  351. A space-separated list of all the events supported by this version of
  352. Tor's USEFEATURE.
  353. "next-circuit/IP:port"
  354. XXX todo.
  355. "dir/status/authority"
  356. "dir/status/fp/<F>"
  357. "dir/status/fp/<F1>+<F2>+<F3>"
  358. "dir/status/all"
  359. "dir/server/fp/<F>"
  360. "dir/server/fp/<F1>+<F2>+<F3>"
  361. "dir/server/d/<D>"
  362. "dir/server/d/<D1>+<D2>+<D3>"
  363. "dir/server/authority"
  364. "dir/server/all"
  365. A series of lines listing directory contents, provided according to the
  366. specification for the URLs listed in Section 4.4 of dir-spec.txt. Note
  367. that Tor MUST NOT provide private information, such as descriptors for
  368. routers not marked as general-purpose. When asked for 'authority'
  369. information for which this Tor is not authoritative, Tor replies with
  370. an empty string.
  371. "status/circuit-established"
  372. "status/..."
  373. These provide the current internal Tor values for various Tor
  374. states. See Section 4.1.10 for explanations. (Only a few of the
  375. status events are available as getinfo's currently. Let us know if
  376. you want more exposed.)
  377. Examples:
  378. C: GETINFO version desc/name/moria1
  379. S: 250+desc/name/moria=
  380. S: [Descriptor for moria]
  381. S: .
  382. S: 250-version=Tor 0.1.1.0-alpha-cvs
  383. S: 250 OK
  384. 3.10. EXTENDCIRCUIT
  385. Sent from the client to the server. The format is:
  386. "EXTENDCIRCUIT" SP CircuitID SP
  387. ServerSpec *("," ServerSpec) SP
  388. ("purpose=" Purpose) CRLF
  389. This request takes one of two forms: either the CircuitID is zero, in
  390. which case it is a request for the server to build a new circuit according
  391. to the specified path, or the CircuitID is nonzero, in which case it is a
  392. request for the server to extend an existing circuit with that ID according
  393. to the specified path.
  394. If CircuitID is 0 and "purpose=" is specified, then the circuit's
  395. purpose is set. Two choices are recognized: "general" and
  396. "controller". If not specified, circuits are created as "general".
  397. If the request is successful, the server sends a reply containing a
  398. message body consisting of the CircuitID of the (maybe newly created)
  399. circuit. The syntax is "250" SP "EXTENDED" SP CircuitID CRLF.
  400. 3.11. SETCIRCUITPURPOSE
  401. Sent from the client to the server. The format is:
  402. "SETCIRCUITPURPOSE" SP CircuitID SP Purpose CRLF
  403. This changes the circuit's purpose. See EXTENDCIRCUIT above for details.
  404. 3.12. SETROUTERPURPOSE
  405. Sent from the client to the server. The format is:
  406. "SETROUTERPURPOSE" SP NicknameOrKey SP Purpose CRLF
  407. This changes the descriptor's purpose. See +POSTDESCRIPTOR below
  408. for details.
  409. 3.13. ATTACHSTREAM
  410. Sent from the client to the server. The syntax is:
  411. "ATTACHSTREAM" SP StreamID SP CircuitID CRLF
  412. This message informs the server that the specified stream should be
  413. associated with the specified circuit. Each stream may be associated with
  414. at most one circuit, and multiple streams may share the same circuit.
  415. Streams can only be attached to completed circuits (that is, circuits that
  416. have sent a circuit status 'BUILT' event or are listed as built in a
  417. GETINFO circuit-status request).
  418. If the circuit ID is 0, responsibility for attaching the given stream is
  419. returned to Tor.
  420. Tor responds with "250 OK" if it can attach the stream, 552 if the circuit
  421. or stream didn't exist, or 551 if the stream couldn't be attached for
  422. another reason.
  423. {Implementation note: Tor will close unattached streams by itself,
  424. roughly two minutes after they are born. Let the developers know if
  425. that turns out to be a problem.}
  426. {Implementation note: By default, Tor automatically attaches streams to
  427. circuits itself, unless the configuration variable
  428. "__LeaveStreamsUnattached" is set to "1". Attempting to attach streams
  429. via TC when "__LeaveStreamsUnattached" is false may cause a race between
  430. Tor and the controller, as both attempt to attach streams to circuits.}
  431. {Implementation note: You can try to attachstream to a stream that
  432. has already sent a connect or resolve request but hasn't succeeded
  433. yet, in which case Tor will detach the stream from its current circuit
  434. before proceeding with the new attach request.}
  435. 3.14. POSTDESCRIPTOR
  436. Sent from the client to the server. The syntax is:
  437. "+POSTDESCRIPTOR" ("purpose=" Purpose) CRLF Descriptor CRLF "." CRLF
  438. This message informs the server about a new descriptor. If Purpose is
  439. specified, it must be either "general" or "controller", else we
  440. return a 552 error.
  441. The descriptor, when parsed, must contain a number of well-specified
  442. fields, including fields for its nickname and identity.
  443. If there is an error in parsing the descriptor, the server must send a "554
  444. Invalid descriptor" reply. If the descriptor is well-formed but the server
  445. chooses not to add it, it must reply with a 251 message whose body explains
  446. why the server was not added. If the descriptor is added, Tor replies with
  447. "250 OK".
  448. 3.15. REDIRECTSTREAM
  449. Sent from the client to the server. The syntax is:
  450. "REDIRECTSTREAM" SP StreamID SP Address (SP Port) CRLF
  451. Tells the server to change the exit address on the specified stream. If
  452. Port is specified, changes the destination port as well. No remapping
  453. is performed on the new provided address.
  454. To be sure that the modified address will be used, this event must be sent
  455. after a new stream event is received, and before attaching this stream to
  456. a circuit.
  457. Tor replies with "250 OK" on success.
  458. 3.16. CLOSESTREAM
  459. Sent from the client to the server. The syntax is:
  460. "CLOSESTREAM" SP StreamID SP Reason *(SP Flag) CRLF
  461. Tells the server to close the specified stream. The reason should be one
  462. of the Tor RELAY_END reasons given in tor-spec.txt, as a decimal. Flags is
  463. not used currently; Tor servers SHOULD ignore unrecognized flags. Tor may
  464. hold the stream open for a while to flush any data that is pending.
  465. Tor replies with "250 OK" on success, or a 512 if there aren't enough
  466. arguments, or a 552 if it doesn't recognize the StreamID or reason.
  467. 3.17. CLOSECIRCUIT
  468. The syntax is:
  469. CLOSECIRCUIT SP CircuitID *(SP Flag) CRLF
  470. Flag = "IfUnused"
  471. Tells the server to close the specified circuit. If "IfUnused" is
  472. provided, do not close the circuit unless it is unused.
  473. Other flags may be defined in the future; Tor SHOULD ignore unrecognized
  474. flags.
  475. Tor replies with "250 OK" on success, or a 512 if there aren't enough
  476. arguments, or a 552 if it doesn't recognize the CircuitID.
  477. 3.18. QUIT
  478. Tells the server to hang up on this controller connection. This command
  479. can be used before authenticating.
  480. 3.19. USEFEATURE
  481. The syntax is:
  482. "USEFEATURE" *(SP FeatureName) CRLF
  483. FeatureName = 1*(ALPHA / DIGIT / "_" / "-")
  484. Sometimes extensions to the controller protocol break compatibility with
  485. older controllers. In this case, whenever possible, the extensions are
  486. first included in Tor disabled by default, and only enabled on a given
  487. controller connection when the "USEFEATURE" command is given. Once a
  488. "USEFEATURE" command is given, it applies to all subsequent interactions on
  489. the same connection; to disable an enabled feature, a new controller
  490. connection must be opened.
  491. This is a forward-compatibility mechanism; each feature will eventually
  492. become a regular part of the control protocol in some future version of Tor.
  493. Tor will ignore a request to use any feature that is already on by default.
  494. Tor will give a "552" error if any requested feature is not recognized.
  495. Feature names are case-insensitive.
  496. EXTENDED_EVENTS
  497. Same as passing 'EXTENDED' to SETEVENTS; this is the preferred way to
  498. request the extended event syntax.
  499. This will not be always-enabled until at least XXX (or, at least two
  500. stable releases after XXX, the release where it was first used for
  501. anything.)
  502. VERBOSE_NAMES
  503. Instead of ServerID as specified above, the controller should
  504. identify ORs by LongName in events and GETINFO results. This format is
  505. strictly more informative: rather than including Nickname for
  506. known Named routers and Fingerprint for unknown or unNamed routers, the
  507. LongName format includes a Fingerprint, an indication of Named status,
  508. and a Nickname (if one is known).
  509. This will not be always-enabled until at least 0.1.4.x (or at least two
  510. stable releases after 0.1.2.2-alpha, the release where it was first
  511. available.)
  512. 4. Replies
  513. Reply codes follow the same 3-character format as used by SMTP, with the
  514. first character defining a status, the second character defining a
  515. subsystem, and the third designating fine-grained information.
  516. The TC protocol currently uses the following first characters:
  517. 2yz Positive Completion Reply
  518. The command was successful; a new request can be started.
  519. 4yz Temporary Negative Completion reply
  520. The command was unsuccessful but might be reattempted later.
  521. 5yz Permanent Negative Completion Reply
  522. The command was unsuccessful; the client should not try exactly
  523. that sequence of commands again.
  524. 6yz Asynchronous Reply
  525. Sent out-of-order in response to an earlier SETEVENTS command.
  526. The following second characters are used:
  527. x0z Syntax
  528. Sent in response to ill-formed or nonsensical commands.
  529. x1z Protocol
  530. Refers to operations of the Tor Control protocol.
  531. x5z Tor
  532. Refers to actual operations of Tor system.
  533. The following codes are defined:
  534. 250 OK
  535. 251 Operation was unnecessary
  536. [Tor has declined to perform the operation, but no harm was done.]
  537. 451 Resource exhausted
  538. 500 Syntax error: protocol
  539. 510 Unrecognized command
  540. 511 Unimplemented command
  541. 512 Syntax error in command argument
  542. 513 Unrecognized command argument
  543. 514 Authentication required
  544. 515 Bad authentication
  545. 550 Unspecified Tor error
  546. 551 Internal error
  547. [Something went wrong inside Tor, so that the client's
  548. request couldn't be fulfilled.]
  549. 552 Unrecognized entity
  550. [A configuration key, a stream ID, circuit ID, event,
  551. mentioned in the command did not actually exist.]
  552. 553 Invalid configuration value
  553. [The client tried to set a configuration option to an
  554. incorrect, ill-formed, or impossible value.]
  555. 554 Invalid descriptor
  556. 555 Unmanaged entity
  557. 650 Asynchronous event notification
  558. Unless specified to have specific contents, the human-readable messages
  559. in error replies should not be relied upon to match those in this document.
  560. 4.1. Asynchronous events
  561. These replies can be sent after a corresponding SETEVENTS command has been
  562. received. They will not be interleaved with other Reply elements, but they
  563. can appear between a command and its corresponding reply. For example,
  564. this sequence is possible:
  565. C: SETEVENTS CIRC
  566. S: 250 OK
  567. C: GETCONF SOCKSPORT ORPORT
  568. S: 650 CIRC 1000 EXTENDED moria1,moria2
  569. S: 250-SOCKSPORT=9050
  570. S: 250 ORPORT=0
  571. But this sequence is disallowed:
  572. C: SETEVENTS CIRC
  573. S: 250 OK
  574. C: GETCONF SOCKSPORT ORPORT
  575. S: 250-SOCKSPORT=9050
  576. S: 650 CIRC 1000 EXTENDED moria1,moria2
  577. S: 250 ORPORT=0
  578. Clients MUST tolerate more arguments in an asynchonous reply than
  579. expected, and MUST tolerate more lines in an asynchronous reply than
  580. expected. For instance, a client that expects a CIRC message like:
  581. 650 CIRC 1000 EXTENDED moria1,moria2
  582. must tolerate:
  583. 650-CIRC 1000 EXTENDED moria1,moria2 0xBEEF
  584. 650-EXTRAMAGIC=99
  585. 650 ANONYMITY=high
  586. If clients ask for extended events, then each event line as specified below
  587. will be followed by additional extensions. Additional lines will be of the
  588. form
  589. "650" ("-"/" ") KEYWORD ["=" ARGUMENTS] CRLF
  590. Additional arguments will be of the form
  591. SP KEYWORD ["=" ( QuotedString / * NonSpDquote ) ]
  592. Such clients MUST tolerate lines with keywords they do not recognize.
  593. 4.1.1. Circuit status changed
  594. The syntax is:
  595. "650" SP "CIRC" SP CircuitID SP CircStatus [SP Path]
  596. [SP "REASON=" Reason [SP "REMOTE_REASON=" Reason]] CRLF
  597. CircStatus =
  598. "LAUNCHED" / ; circuit ID assigned to new circuit
  599. "BUILT" / ; all hops finished, can now accept streams
  600. "EXTENDED" / ; one more hop has been completed
  601. "FAILED" / ; circuit closed (was not built)
  602. "CLOSED" ; circuit closed (was built)
  603. Path = ServerID *("," ServerID)
  604. Reason = "NONE" / "TORPROTOCOL" / "INTERNAL" / "REQUESTED" /
  605. "HIBERNATING" / "RESOURCELIMIT" / "CONNECTFAILED" /
  606. "OR_IDENTITY" / "OR_CONN_CLOSED" / "TIMEOUT" /
  607. "FINISHED" / "DESTROYED" / "NOPATH" / "NOSUCHSERVICE"
  608. The path is provided only when the circuit has been extended at least one
  609. hop.
  610. The "REASON" field is provided only for FAILED and CLOSED events, and only
  611. if extended events are enabled (see 3.19). Clients MUST accept reasons
  612. not listed above. Reasons are as given in tor-spec.txt, except for:
  613. NOPATH (Not enough nodes to make circuit)
  614. The "REMOTE_REASON" field is provided only when we receive a DESTROY or
  615. TRUNCATE cell, and only if extended events are enabled. It contains the
  616. actual reason given by the remote OR for closing the circuit. Clients MUST
  617. accept reasons not listed above. Reasons are as listed in tor-spec.txt.
  618. 4.1.2. Stream status changed
  619. The syntax is:
  620. "650" SP "STREAM" SP StreamID SP StreamStatus SP CircID SP Target
  621. [SP "REASON=" Reason [ SP "REMOTE_REASON=" Reason ]] CRLF
  622. StreamStatus =
  623. "NEW" / ; New request to connect
  624. "NEWRESOLVE" / ; New request to resolve an address
  625. "REMAP" / ; Address re-mapped to another
  626. "SENTCONNECT" / ; Sent a connect cell along a circuit
  627. "SENTRESOLVE" / ; Sent a resolve cell along a circuit
  628. "SUCCEEDED" / ; Received a reply; stream established
  629. "FAILED" / ; Stream failed and not retriable
  630. "CLOSED" / ; Stream closed
  631. "DETACHED" ; Detached from circuit; still retriable
  632. Target = Address ":" Port
  633. The circuit ID designates which circuit this stream is attached to. If
  634. the stream is unattached, the circuit ID "0" is given.
  635. Reason = "MISC" / "RESOLVEFAILED" / "CONNECTREFUSED" /
  636. "EXITPOLICY" / "DESTROY" / "DONE" / "TIMEOUT" /
  637. "HIBERNATING" / "INTERNAL"/ "RESOURCELIMIT" /
  638. "CONNRESET" / "TORPROTOCOL" / "NOTDIRECTORY" / "END"
  639. The "REASON" field is provided only for FAILED, CLOSED, and DETACHED
  640. events, and only if extended events are enabled (see 3.19). Clients MUST
  641. accept reasons not listed above. Reasons are as given in tor-spec.txt,
  642. except for:
  643. END (We received a RELAY_END cell from the other side of thise
  644. stream.)
  645. The "REMOTE_REASON" field is provided only when we receive a RELAY_END
  646. cell, and only if extended events are enabled. It contains the actual
  647. reason given by the remote OR for closing the stream. Clients MUST accept
  648. reasons not listed above. Reasons are as listed in tor-spec.txt.
  649. 4.1.3. OR Connection status changed
  650. The syntax is:
  651. "650" SP "ORCONN" SP (ServerID / Target) SP ORStatus [ SP "REASON="
  652. Reason ] [ SP "NCIRCS=" NumCircuits ]
  653. ORStatus = "NEW" / "LAUNCHED" / "CONNECTED" / "FAILED" / "CLOSED"
  654. NEW is for incoming connections, and LAUNCHED is for outgoing
  655. connections. CONNECTED means the TLS handshake has finished (in
  656. either direction). FAILED means a connection is being closed that
  657. hasn't finished its handshake, and CLOSED is for connections that
  658. have handshaked.
  659. A ServerID is specified unless it's a NEW connection, in which
  660. case we don't know what server it is yet, so we use Address:Port.
  661. If extended events are enabled (see 3.19), optional reason and
  662. circuit counting information is provided for CLOSED and FAILED
  663. events.
  664. Reason = "MISC" / "DONE" / "CONNECTREFUSED" /
  665. "IDENTITY" / "CONNECTRESET" / "TIMEOUT" / "NOROUTE" /
  666. "IOERROR"
  667. NumCircuits counts both established and pending circuits.
  668. 4.1.4. Bandwidth used in the last second
  669. The syntax is:
  670. "650" SP "BW" SP BytesRead SP BytesWritten *(SP Type "=" Num)
  671. BytesRead = 1*DIGIT
  672. BytesWritten = 1*DIGIT
  673. Type = "DIR" / "OR" / "EXIT" / "APP" / ...
  674. Num = 1*DIGIT
  675. BytesRead and BytesWritten are the totals. In Tor 0.1.x.y-alpha
  676. and later, we also include a breakdown of the connection types
  677. that used bandwidth this second (not implemented yet).
  678. 4.1.5. Log messages
  679. The syntax is:
  680. "650" SP Severity SP ReplyText
  681. or
  682. "650+" Severity CRLF Data
  683. Severity = "DEBUG" / "INFO" / "NOTICE" / "WARN"/ "ERR"
  684. 4.1.6. New descriptors available
  685. Syntax:
  686. "650" SP "NEWDESC" 1*(SP ServerID)
  687. 4.1.7. New Address mapping
  688. Syntax:
  689. "650" SP "ADDRMAP" SP Address SP Address SP Expiry
  690. Expiry = DQUOTE ISOTime DQUOTE / "NEVER"
  691. Expiry is expressed as the local time (rather than GMT).
  692. [XXX We should rename this to ADDRESSMAP. -RD]
  693. [FFF We should add a SOURCE=%s argument for extended events,
  694. which specifies what exit node told us this addressmap. -RD]
  695. 4.1.8. Descriptors uploaded to us in our role as authoritative dirserver
  696. Syntax:
  697. "650" "+" "AUTHDIR_NEWDESCS" CRLF Action CRLF Message CRLF
  698. Descriptor CRLF "." CRLF
  699. Action = "ACCEPTED" / "DROPPED" / "REJECTED"
  700. Message = Text
  701. 4.1.9. Our descriptor changed
  702. Syntax:
  703. "650" SP "DESCCHANGED"
  704. [First added in 0.1.2.2-alpha.]
  705. 4.1.10. Status events
  706. Status events (STATUS_GENERAL, STATUS_CLIENT, and STATUS_SERVER) are sent
  707. based on occurrences in the Tor process pertaining to the general state of
  708. the program. Generally, they correspond to log messages of severity Notice
  709. or higher. They differ from log messages in that their format is a
  710. specified interface.
  711. Syntax:
  712. "650" SP StatusType SP StatusSeverity SP StatusAction
  713. [SP StatusArguments] CRLF
  714. StatusType = "STATUS_GENERAL" / "STATUS_CLIENT" / "STATUS_SERVER"
  715. StatusSeverity = "NOTICE" / "WARN" / "ERR"
  716. StatusAction = 1*ALPHA
  717. StatusArguments = StatusArgument *(SP StatusArgument)
  718. StatusArgument = StatusKeyword '=' StatusValue
  719. StatusKeyword = 1*(ALNUM / "_")
  720. StatusValue = 1*(ALNUM / '_') / QuotedString
  721. Action is a string, and Arguments is a series of keyword=value
  722. pairs on the same line. Values may be space-terminated strings,
  723. or quoted strings.
  724. These events are always produced with EXTENDED_EVENTS and
  725. VERBOSE_NAMES; see the explanations in the USEFEATURE section
  726. for details.
  727. Controllers MUST tolerate unrecognized actions, MUST tolerate
  728. unrecognized arguments, MUST tolerate missing arguments, and MUST
  729. tolerate arguments that arrive in any order.
  730. Each event description below is accompanied by a recommendation for
  731. controllers. These recommendations are suggestions only; no controller
  732. is required to implement them.
  733. Actions for STATUS_GENERAL events can be as follows:
  734. CLOCK_JUMPED
  735. "TIME=NUM"
  736. Tor spent enough time without CPU cycles that it has closed all
  737. its circuits and will establish them anew. This typically
  738. happens when a laptop goes to sleep and then wakes up again. It
  739. also happens when the system is swapping so heavily that Tor is
  740. starving. The "time" argument specifies the number of seconds Tor
  741. thinks it was unconscious for (or alternatively, the number of
  742. seconds it went back in time).
  743. This status event is sent as NOTICE severity normally, but WARN
  744. severity if Tor is acting as a server currently.
  745. {Recommendation for controller: ignore it, since we don't really
  746. know what the user should do anyway. Hm.}
  747. DANGEROUS_VERSION
  748. "CURRENT=version"
  749. "REASON=NEW/OLD/UNRECOMMENDED"
  750. "RECOMMENDED=\"version, version, ...\""
  751. Tor has found that directory servers don't recommend its version of
  752. the Tor software. RECOMMENDED is a comma-and-space-separated string
  753. of Tor versions that are recommended. REASON is NEW if this version
  754. of Tor is newer than any recommended version, OLD if this version of
  755. Tor is older than any recommended version, and UNRECOMMENDED if
  756. some recommended versions of Tor are newer and some are old than this
  757. version.
  758. {Controllers may want to suggest that the user upgrade OLD or
  759. UNRECOMMENDED versions. NEW versions may be known-insecure, or may
  760. simply be development versions.}
  761. TOO_MANY_CONNECTIONS
  762. "CURRENT=NUM"
  763. Tor has reached its ulimit -n or whatever the native limit is on file
  764. descriptors or sockets. CURRENT is the number of sockets Tor
  765. currently has open. The user should really do something about
  766. this. The "current" argument shows the number of connections currently
  767. open.
  768. {Controllers may recommend that the user increase the limit, or
  769. increase it for them. Recommendations should be phrased in an
  770. OS-appropriate way and automated when possible.}
  771. BUG
  772. "REASON=STRING"
  773. Tor has encountered a situation that its developers never expected,
  774. and the developers would like to learn that it happened. Perhaps
  775. the controller can explain this to the user and encourage her to
  776. file a bug report?
  777. {Controllers should log bugs, but shouldn't annoy the user in case a
  778. bug appears frequently.}
  779. CLOCK_SKEWED
  780. SKEW="+" / "-" SECONDS
  781. SOURCE="DIRSERV:IP:Port" / "NETWORKSTATUS:IP:PORT"
  782. If "SKEW" is present, it's an estimate of how far we are from the
  783. time declared in the source. If the source is a DIRSERV, we got
  784. the current time from a connection to a dirserver. If the source is
  785. a NETWORKSTATUS, we decided we're skewed because we got a
  786. networkstatus from far in the future.
  787. {Controllers may want to warn the user if the skew is high, or if
  788. multiple skew messages appear at severity WARN. Controllers
  789. shouldn't blindly adjust the clock, since the more accurate source
  790. of skew info (DIRSERV) is currently unauthenticated.}
  791. BAD_LIBEVENT
  792. "METHOD=" libevent method
  793. "VERSION=" libevent version
  794. "BADNESS=" "BROKEN" / "BUGGY" / "SLOW"
  795. "RECOVERED=" "NO" / "YES"
  796. Tor knows about bugs in using the configured event method in this
  797. version of libevent. "BROKEN" libevents won't work at all;
  798. "BUGGY" libevents might work okay; "SLOW" libevents will work
  799. fine, but not quickly. If "RECOVERED" is YES, Tor managed to
  800. switch to a more reliable (but probably slower!) libevent method.
  801. {Controllers may want to warn the user if this event occurs, though
  802. generally it's the fault of whoever built the Tor binary and there's
  803. not much the user can do besides upgrade libevent or upgrade the
  804. binary.}
  805. DIR_ALL_UNREACHABLE
  806. Tor believes that none of the known directory servers are
  807. reachable -- this is most likely because the local network is
  808. down or otherwise not working, and might help to explain for the
  809. user why Tor appears to be broken.
  810. {Controllers may want to warn the user if this event occurs; further
  811. action is generally not possible.}
  812. Actions for STATUS_CLIENT events can be as follows:
  813. ENOUGH_DIR_INFO
  814. Tor now knows enough network-status documents and enough server
  815. descriptors that it's going to start trying to build circuits now.
  816. {Controllers may want to use this event to decide when to indicate
  817. progress to their users, but should not interrupt the user's browsing
  818. to tell them so.}
  819. NOT_ENOUGH_DIR_INFO
  820. We discarded expired statuses and router descriptors to fall
  821. below the desired threshold of directory information. We won't
  822. try to build any circuits until ENOUGH_DIR_INFO occurs again.
  823. {Controllers may want to use this event to decide when to indicate
  824. progress to their users, but should not interrupt the user's browsing
  825. to tell them so.}
  826. CIRCUIT_ESTABLISHED
  827. Tor is able to establish circuits for client use. This event will
  828. only be sent if we just built a circuit that changed our mind --
  829. that is, prior to this event we didn't know whether we could
  830. establish circuits.
  831. {Suggested use: controllers can notify their users that Tor is
  832. ready for use as a client once they see this status event. [Perhaps
  833. controllers should also have a timeout if too much time passes and
  834. this event hasn't arrived, to give tips on how to troubleshoot.
  835. On the other hand, hopefully Tor will send further status events
  836. if it can identify the problem.]}
  837. CIRCUIT_NOT_ESTABLISHED
  838. "REASON=" "EXTERNAL_ADDRESS" / "DIR_ALL_UNREACHABLE" / "CLOCK_JUMPED"
  839. We are no longer confident that we can build circuits. The "reason"
  840. keyword provides an explanation: which other status event type caused
  841. our lack of confidence.
  842. {Controllers may want to use this event to decide when to indicate
  843. progress to their users, but should not interrupt the user's browsing
  844. to do so.}
  845. [Note: only REASON=CLOCK_JUMPED is implemented currently.]
  846. DANGEROUS_SOCKS
  847. "PROTOCOL=SOCKS4/SOCKS5"
  848. "ADDRESS=IP:port"
  849. A connection was made to Tor's SOCKS port using one of the SOCKS
  850. approaches that doesn't support hostnames -- only raw IP addresses.
  851. If the client application got this address from gethostbyname(),
  852. it may be leaking target addresses via DNS.
  853. {Controllers should warn their users when this occurs, unless they
  854. happen to know that the application using Tor is in fact doing so
  855. correctly (e.g., because it is part of a distributed bundle).}
  856. SOCKS_UNKNOWN_PROTOCOL
  857. "DATA=string"
  858. A connection was made to Tor's SOCKS port that tried to use it
  859. for something other than the SOCKS protocol. Perhaps the user is
  860. using Tor as an HTTP proxy? The DATA is the first few characters
  861. sent to Tor on the SOCKS port.
  862. {Controllers may want to warn their users when this occurs: it
  863. indicates a misconfigured application.}
  864. SOCKS_BAD_HOSTNAME
  865. "HOSTNAME=QuotedString"
  866. Some application gave us a funny-looking hostname. Perhaps
  867. it is broken? In any case it won't work with Tor and the user
  868. should know.
  869. {Controllers may want to warn their users when this occurs: it
  870. usually indicates a misconfigured application.}
  871. Actions for STATUS_SERVER can be as follows:
  872. EXTERNAL_ADDRESS
  873. "ADDRESS=IP"
  874. "HOSTNAME=NAME"
  875. "METHOD=CONFIGURED/DIRSERV/RESOLVED/INTERFACE/GETHOSTNAME"
  876. Our best idea for our externally visible IP has changed to 'IP'.
  877. If 'HOSTNAME' is present, we got the new IP by resolving 'NAME'. If the
  878. method is 'CONFIGURED', the IP was given verbatim as a configuration
  879. option. If the method is 'RESOLVED', we resolved the Address
  880. configuration option to get the IP. If the method is 'GETHOSTNAME',
  881. we resolved our hostname to get the IP. If the method is 'INTERFACE',
  882. we got the address of one of our network interfaces to get the IP. If
  883. the method is 'DIRSERV', a directory server told us a guess for what
  884. our IP might be.
  885. {Controllers may want to record this info and display it to the user.}
  886. CHECKING_REACHABILITY
  887. "ORADDRESS=IP:port"
  888. "DIRADDRESS=IP:port"
  889. We're going to start testing the reachability of our external OR port
  890. or directory port.
  891. {This event could effect the controller's idea of server status, but
  892. the controller should not interrupt the user to tell them so.}
  893. REACHABILITY_SUCCEEDED
  894. "ORADDRESS=IP:port"
  895. "DIRADDRESS=IP:port"
  896. We successfully verified the reachability of our external OR port or
  897. directory port.
  898. {This event could effect the controller's idea of server status, but
  899. the controller should not interrupt the user to tell them so.}
  900. GOOD_SERVER_DESCRIPTOR
  901. We successfully uploaded our server descriptor to each of the
  902. directory authorities, with no complaints.
  903. {This event could effect the controller's idea of server status, but
  904. the controller should not interrupt the user to tell them so.}
  905. NAMESERVER_STATUS
  906. "NS=addr"
  907. "STATUS=" "UP" / "DOWN"
  908. "ERR=" message
  909. One of our nameservers has changed status.
  910. // actually notice
  911. {This event could effect the controller's idea of server status, but
  912. the controller should not interrupt the user to tell them so.}
  913. NAMESERVER_ALL_DOWN
  914. All of our nameservers have gone down.
  915. {This is a problem; if it happens often without the nameservers
  916. coming up again, the user needs to configure more or better
  917. nameservers.}
  918. DNS_HIJACKED
  919. Our DNS provider is providing an address when it should be saying
  920. "NOTFOUND"; Tor will treat the address as a synonym for "NOTFOUND".
  921. {This is an annoyance; controllers may want to tell admins that their
  922. DNS provider is not to be trusted.}
  923. DNS_USELESS
  924. Our DNS provider is giving a hijacked address instead of well-known
  925. websites; Tor will not try to be an exit node.
  926. {Controllers could warn the admin if the server is running as an
  927. exit server: the admin needs to configure a good DNS server.
  928. Alternatively, this happens a lot in some restrictive environments
  929. (hotels, universities, coffeeshops) when the user hasn't registered.}
  930. BAD_SERVER_DESCRIPTOR
  931. "DIRAUTH=addr:port"
  932. "REASON=string"
  933. A directory authority rejected our descriptor. Possible reasons
  934. include malformed descriptors, incorrect keys, highly skewed clocks,
  935. and so on.
  936. {Controllers should warn the admin, and try to cope if they can.}
  937. ACCEPTED_SERVER_DESCRIPTOR
  938. "DIRAUTH=addr:port"
  939. A single directory authority accepted our descriptor.
  940. // actually notice
  941. {This event could effect the controller's idea of server status, but
  942. the controller should not interrupt the user to tell them so.}
  943. REACHABILITY_FAILED
  944. "ORADDRESS=IP:port"
  945. "DIRADDRESS=IP:port"
  946. We failed to connect to our external OR port or directory port
  947. successfully.
  948. {This event could effect the controller's idea of server status. The
  949. controller should warn the admin and suggest reasonable steps to take.}
  950. 4.1.11. Our set of guard nodes has changed
  951. Syntax:
  952. "650" SP "GUARDS" SP Type SP Name SP Status ... CRLF
  953. Type = "ENTRY"
  954. Name = The (possibly verbose) nickname of the guard affected.
  955. Status = "NEW" | "UP" | "DOWN" | "BAD" | "GOOD" | "DROPPED"
  956. [explain states. XXX]
  957. 4.1.12. Network status has changed
  958. Syntax:
  959. "650" "+" "NS" CRLF 1*NetworkStatus "." CRLF
  960. [First added in 0.1.2.3-alpha]
  961. 5. Implementation notes
  962. 5.1. Authentication
  963. By default, the current Tor implementation trusts all local users.
  964. If the 'CookieAuthentication' option is true, Tor writes a "magic cookie"
  965. file named "control_auth_cookie" into its data directory. To authenticate,
  966. the controller must send the contents of this file, encoded in hexadecimal.
  967. If the 'HashedControlPassword' option is set, it must contain the salted
  968. hash of a secret password. The salted hash is computed according to the
  969. S2K algorithm in RFC 2440 (OpenPGP), and prefixed with the s2k specifier.
  970. This is then encoded in hexadecimal, prefixed by the indicator sequence
  971. "16:". Thus, for example, the password 'foo' could encode to:
  972. 16:660537E3E1CD49996044A3BF558097A981F539FEA2F9DA662B4626C1C2
  973. ++++++++++++++++**^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  974. salt hashed value
  975. indicator
  976. You can generate the salt of a password by calling
  977. 'tor --hash-password <password>'
  978. or by using the example code in the Python and Java controller libraries.
  979. To authenticate under this scheme, the controller sends Tor the original
  980. secret that was used to generate the password.
  981. 5.2. Don't let the buffer get too big.
  982. If you ask for lots of events, and 16MB of them queue up on the buffer,
  983. the Tor process will close the socket.
  984. 5.3. Backward compatibility with v0 control protocol.
  985. For backward compatibility with the "version 0" control protocol, Tor checks
  986. whether the third octet the first command is zero. If it is, Tor
  987. assumes that version 0 is in use. This feature is deprecated, and will be
  988. removed in the 0.1.3.x Tor development series.
  989. In order to detect which version of the protocol is supported controllers
  990. should send the sequence [00 00 0D 0A]. This is a valid and unrecognized
  991. command in both protocol versions, and implementations can detect which
  992. error they have received.