Bitcoin Core  27.99.0
P2P Digital Currency
torcontrol.cpp
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1 // Copyright (c) 2015-2022 The Bitcoin Core developers
2 // Copyright (c) 2017 The Zcash developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 
6 #include <torcontrol.h>
7 
8 #include <chainparams.h>
9 #include <chainparamsbase.h>
10 #include <common/args.h>
11 #include <compat/compat.h>
12 #include <crypto/hmac_sha256.h>
13 #include <logging.h>
14 #include <net.h>
15 #include <netaddress.h>
16 #include <netbase.h>
17 #include <random.h>
18 #include <tinyformat.h>
19 #include <util/check.h>
20 #include <util/fs.h>
21 #include <util/readwritefile.h>
22 #include <util/strencodings.h>
23 #include <util/string.h>
24 #include <util/thread.h>
25 #include <util/time.h>
26 
27 #include <algorithm>
28 #include <cassert>
29 #include <cstdlib>
30 #include <deque>
31 #include <functional>
32 #include <map>
33 #include <optional>
34 #include <set>
35 #include <thread>
36 #include <utility>
37 #include <vector>
38 
39 #include <event2/buffer.h>
40 #include <event2/bufferevent.h>
41 #include <event2/event.h>
42 #include <event2/thread.h>
43 #include <event2/util.h>
44 
46 const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT);
48 static const int TOR_COOKIE_SIZE = 32;
50 static const int TOR_NONCE_SIZE = 32;
52 static const std::string TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash";
54 static const std::string TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash";
56 static const float RECONNECT_TIMEOUT_START = 1.0;
58 static const float RECONNECT_TIMEOUT_EXP = 1.5;
63 static const int MAX_LINE_LENGTH = 100000;
64 static const uint16_t DEFAULT_TOR_SOCKS_PORT = 9050;
65 
66 /****** Low-level TorControlConnection ********/
67 
69  : base(_base)
70 {
71 }
72 
74 {
75  if (b_conn)
76  bufferevent_free(b_conn);
77 }
78 
79 void TorControlConnection::readcb(struct bufferevent *bev, void *ctx)
80 {
81  TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
82  struct evbuffer *input = bufferevent_get_input(bev);
83  size_t n_read_out = 0;
84  char *line;
85  assert(input);
86  // If there is not a whole line to read, evbuffer_readln returns nullptr
87  while((line = evbuffer_readln(input, &n_read_out, EVBUFFER_EOL_CRLF)) != nullptr)
88  {
89  std::string s(line, n_read_out);
90  free(line);
91  if (s.size() < 4) // Short line
92  continue;
93  // <status>(-|+| )<data><CRLF>
94  self->message.code = ToIntegral<int>(s.substr(0, 3)).value_or(0);
95  self->message.lines.push_back(s.substr(4));
96  char ch = s[3]; // '-','+' or ' '
97  if (ch == ' ') {
98  // Final line, dispatch reply and clean up
99  if (self->message.code >= 600) {
100  // (currently unused)
101  // Dispatch async notifications to async handler
102  // Synchronous and asynchronous messages are never interleaved
103  } else {
104  if (!self->reply_handlers.empty()) {
105  // Invoke reply handler with message
106  self->reply_handlers.front()(*self, self->message);
107  self->reply_handlers.pop_front();
108  } else {
109  LogPrint(BCLog::TOR, "Received unexpected sync reply %i\n", self->message.code);
110  }
111  }
112  self->message.Clear();
113  }
114  }
115  // Check for size of buffer - protect against memory exhaustion with very long lines
116  // Do this after evbuffer_readln to make sure all full lines have been
117  // removed from the buffer. Everything left is an incomplete line.
118  if (evbuffer_get_length(input) > MAX_LINE_LENGTH) {
119  LogPrintf("tor: Disconnecting because MAX_LINE_LENGTH exceeded\n");
120  self->Disconnect();
121  }
122 }
123 
124 void TorControlConnection::eventcb(struct bufferevent *bev, short what, void *ctx)
125 {
126  TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
127  if (what & BEV_EVENT_CONNECTED) {
128  LogPrint(BCLog::TOR, "Successfully connected!\n");
129  self->connected(*self);
130  } else if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
131  if (what & BEV_EVENT_ERROR) {
132  LogPrint(BCLog::TOR, "Error connecting to Tor control socket\n");
133  } else {
134  LogPrint(BCLog::TOR, "End of stream\n");
135  }
136  self->Disconnect();
137  self->disconnected(*self);
138  }
139 }
140 
141 bool TorControlConnection::Connect(const std::string& tor_control_center, const ConnectionCB& _connected, const ConnectionCB& _disconnected)
142 {
143  if (b_conn) {
144  Disconnect();
145  }
146 
147  const std::optional<CService> control_service{Lookup(tor_control_center, DEFAULT_TOR_CONTROL_PORT, fNameLookup)};
148  if (!control_service.has_value()) {
149  LogPrintf("tor: Failed to look up control center %s\n", tor_control_center);
150  return false;
151  }
152 
153  struct sockaddr_storage control_address;
154  socklen_t control_address_len = sizeof(control_address);
155  if (!control_service.value().GetSockAddr(reinterpret_cast<struct sockaddr*>(&control_address), &control_address_len)) {
156  LogPrintf("tor: Error parsing socket address %s\n", tor_control_center);
157  return false;
158  }
159 
160  // Create a new socket, set up callbacks and enable notification bits
161  b_conn = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE);
162  if (!b_conn) {
163  return false;
164  }
165  bufferevent_setcb(b_conn, TorControlConnection::readcb, nullptr, TorControlConnection::eventcb, this);
166  bufferevent_enable(b_conn, EV_READ|EV_WRITE);
167  this->connected = _connected;
168  this->disconnected = _disconnected;
169 
170  // Finally, connect to tor_control_center
171  if (bufferevent_socket_connect(b_conn, reinterpret_cast<struct sockaddr*>(&control_address), control_address_len) < 0) {
172  LogPrintf("tor: Error connecting to address %s\n", tor_control_center);
173  return false;
174  }
175  return true;
176 }
177 
179 {
180  if (b_conn)
181  bufferevent_free(b_conn);
182  b_conn = nullptr;
183 }
184 
185 bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler)
186 {
187  if (!b_conn)
188  return false;
189  struct evbuffer *buf = bufferevent_get_output(b_conn);
190  if (!buf)
191  return false;
192  evbuffer_add(buf, cmd.data(), cmd.size());
193  evbuffer_add(buf, "\r\n", 2);
194  reply_handlers.push_back(reply_handler);
195  return true;
196 }
197 
198 /****** General parsing utilities ********/
199 
200 /* Split reply line in the form 'AUTH METHODS=...' into a type
201  * 'AUTH' and arguments 'METHODS=...'.
202  * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
203  * the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24).
204  */
205 std::pair<std::string,std::string> SplitTorReplyLine(const std::string &s)
206 {
207  size_t ptr=0;
208  std::string type;
209  while (ptr < s.size() && s[ptr] != ' ') {
210  type.push_back(s[ptr]);
211  ++ptr;
212  }
213  if (ptr < s.size())
214  ++ptr; // skip ' '
215  return make_pair(type, s.substr(ptr));
216 }
217 
224 std::map<std::string,std::string> ParseTorReplyMapping(const std::string &s)
225 {
226  std::map<std::string,std::string> mapping;
227  size_t ptr=0;
228  while (ptr < s.size()) {
229  std::string key, value;
230  while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
231  key.push_back(s[ptr]);
232  ++ptr;
233  }
234  if (ptr == s.size()) // unexpected end of line
235  return std::map<std::string,std::string>();
236  if (s[ptr] == ' ') // The remaining string is an OptArguments
237  break;
238  ++ptr; // skip '='
239  if (ptr < s.size() && s[ptr] == '"') { // Quoted string
240  ++ptr; // skip opening '"'
241  bool escape_next = false;
242  while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
243  // Repeated backslashes must be interpreted as pairs
244  escape_next = (s[ptr] == '\\' && !escape_next);
245  value.push_back(s[ptr]);
246  ++ptr;
247  }
248  if (ptr == s.size()) // unexpected end of line
249  return std::map<std::string,std::string>();
250  ++ptr; // skip closing '"'
261  std::string escaped_value;
262  for (size_t i = 0; i < value.size(); ++i) {
263  if (value[i] == '\\') {
264  // This will always be valid, because if the QuotedString
265  // ended in an odd number of backslashes, then the parser
266  // would already have returned above, due to a missing
267  // terminating double-quote.
268  ++i;
269  if (value[i] == 'n') {
270  escaped_value.push_back('\n');
271  } else if (value[i] == 't') {
272  escaped_value.push_back('\t');
273  } else if (value[i] == 'r') {
274  escaped_value.push_back('\r');
275  } else if ('0' <= value[i] && value[i] <= '7') {
276  size_t j;
277  // Octal escape sequences have a limit of three octal digits,
278  // but terminate at the first character that is not a valid
279  // octal digit if encountered sooner.
280  for (j = 1; j < 3 && (i+j) < value.size() && '0' <= value[i+j] && value[i+j] <= '7'; ++j) {}
281  // Tor restricts first digit to 0-3 for three-digit octals.
282  // A leading digit of 4-7 would therefore be interpreted as
283  // a two-digit octal.
284  if (j == 3 && value[i] > '3') {
285  j--;
286  }
287  const auto end{i + j};
288  uint8_t val{0};
289  while (i < end) {
290  val *= 8;
291  val += value[i++] - '0';
292  }
293  escaped_value.push_back(char(val));
294  // Account for automatic incrementing at loop end
295  --i;
296  } else {
297  escaped_value.push_back(value[i]);
298  }
299  } else {
300  escaped_value.push_back(value[i]);
301  }
302  }
303  value = escaped_value;
304  } else { // Unquoted value. Note that values can contain '=' at will, just no spaces
305  while (ptr < s.size() && s[ptr] != ' ') {
306  value.push_back(s[ptr]);
307  ++ptr;
308  }
309  }
310  if (ptr < s.size() && s[ptr] == ' ')
311  ++ptr; // skip ' ' after key=value
312  mapping[key] = value;
313  }
314  return mapping;
315 }
316 
317 TorController::TorController(struct event_base* _base, const std::string& tor_control_center, const CService& target):
318  base(_base),
319  m_tor_control_center(tor_control_center), conn(base), reconnect(true), reconnect_timeout(RECONNECT_TIMEOUT_START),
320  m_target(target)
321 {
322  reconnect_ev = event_new(base, -1, 0, reconnect_cb, this);
323  if (!reconnect_ev)
324  LogPrintf("tor: Failed to create event for reconnection: out of memory?\n");
325  // Start connection attempts immediately
326  if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
327  std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
328  LogPrintf("tor: Initiating connection to Tor control port %s failed\n", m_tor_control_center);
329  }
330  // Read service private key if cached
331  std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
332  if (pkf.first) {
333  LogPrint(BCLog::TOR, "Reading cached private key from %s\n", fs::PathToString(GetPrivateKeyFile()));
334  private_key = pkf.second;
335  }
336 }
337 
339 {
340  if (reconnect_ev) {
341  event_free(reconnect_ev);
342  reconnect_ev = nullptr;
343  }
344  if (service.IsValid()) {
346  }
347 }
348 
350 {
351  // NOTE: We can only get here if -onion is unset
352  std::string socks_location;
353  if (reply.code == 250) {
354  for (const auto& line : reply.lines) {
355  if (0 == line.compare(0, 20, "net/listeners/socks=")) {
356  const std::string port_list_str = line.substr(20);
357  std::vector<std::string> port_list = SplitString(port_list_str, ' ');
358 
359  for (auto& portstr : port_list) {
360  if (portstr.empty()) continue;
361  if ((portstr[0] == '"' || portstr[0] == '\'') && portstr.size() >= 2 && (*portstr.rbegin() == portstr[0])) {
362  portstr = portstr.substr(1, portstr.size() - 2);
363  if (portstr.empty()) continue;
364  }
365  socks_location = portstr;
366  if (0 == portstr.compare(0, 10, "127.0.0.1:")) {
367  // Prefer localhost - ignore other ports
368  break;
369  }
370  }
371  }
372  }
373  if (!socks_location.empty()) {
374  LogPrint(BCLog::TOR, "Get SOCKS port command yielded %s\n", socks_location);
375  } else {
376  LogPrintf("tor: Get SOCKS port command returned nothing\n");
377  }
378  } else if (reply.code == 510) { // 510 Unrecognized command
379  LogPrintf("tor: Get SOCKS port command failed with unrecognized command (You probably should upgrade Tor)\n");
380  } else {
381  LogPrintf("tor: Get SOCKS port command failed; error code %d\n", reply.code);
382  }
383 
384  CService resolved;
385  Assume(!resolved.IsValid());
386  if (!socks_location.empty()) {
387  resolved = LookupNumeric(socks_location, DEFAULT_TOR_SOCKS_PORT);
388  }
389  if (!resolved.IsValid()) {
390  // Fallback to old behaviour
391  resolved = LookupNumeric("127.0.0.1", DEFAULT_TOR_SOCKS_PORT);
392  }
393 
394  Assume(resolved.IsValid());
395  LogPrint(BCLog::TOR, "Configuring onion proxy for %s\n", resolved.ToStringAddrPort());
396  Proxy addrOnion = Proxy(resolved, true);
397  SetProxy(NET_ONION, addrOnion);
398 
399  const auto onlynets = gArgs.GetArgs("-onlynet");
400 
401  const bool onion_allowed_by_onlynet{
402  !gArgs.IsArgSet("-onlynet") ||
403  std::any_of(onlynets.begin(), onlynets.end(), [](const auto& n) {
404  return ParseNetwork(n) == NET_ONION;
405  })};
406 
407  if (onion_allowed_by_onlynet) {
408  // If NET_ONION is reachable, then the below is a noop.
409  //
410  // If NET_ONION is not reachable, then none of -proxy or -onion was given.
411  // Since we are here, then -torcontrol and -torpassword were given.
413  }
414 }
415 
417 {
418  if (reply.code == 250) {
419  LogPrint(BCLog::TOR, "ADD_ONION successful\n");
420  for (const std::string &s : reply.lines) {
421  std::map<std::string,std::string> m = ParseTorReplyMapping(s);
422  std::map<std::string,std::string>::iterator i;
423  if ((i = m.find("ServiceID")) != m.end())
424  service_id = i->second;
425  if ((i = m.find("PrivateKey")) != m.end())
426  private_key = i->second;
427  }
428  if (service_id.empty()) {
429  LogPrintf("tor: Error parsing ADD_ONION parameters:\n");
430  for (const std::string &s : reply.lines) {
431  LogPrintf(" %s\n", SanitizeString(s));
432  }
433  return;
434  }
435  service = LookupNumeric(std::string(service_id+".onion"), Params().GetDefaultPort());
436  LogInfo("Got tor service ID %s, advertising service %s\n", service_id, service.ToStringAddrPort());
438  LogPrint(BCLog::TOR, "Cached service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
439  } else {
440  LogPrintf("tor: Error writing service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
441  }
443  // ... onion requested - keep connection open
444  } else if (reply.code == 510) { // 510 Unrecognized command
445  LogPrintf("tor: Add onion failed with unrecognized command (You probably need to upgrade Tor)\n");
446  } else {
447  LogPrintf("tor: Add onion failed; error code %d\n", reply.code);
448  }
449 }
450 
452 {
453  if (reply.code == 250) {
454  LogPrint(BCLog::TOR, "Authentication successful\n");
455 
456  // Now that we know Tor is running setup the proxy for onion addresses
457  // if -onion isn't set to something else.
458  if (gArgs.GetArg("-onion", "") == "") {
459  _conn.Command("GETINFO net/listeners/socks", std::bind(&TorController::get_socks_cb, this, std::placeholders::_1, std::placeholders::_2));
460  }
461 
462  // Finally - now create the service
463  if (private_key.empty()) { // No private key, generate one
464  private_key = "NEW:ED25519-V3"; // Explicitly request key type - see issue #9214
465  }
466  // Request onion service, redirect port.
467  // Note that the 'virtual' port is always the default port to avoid decloaking nodes using other ports.
468  _conn.Command(strprintf("ADD_ONION %s Port=%i,%s", private_key, Params().GetDefaultPort(), m_target.ToStringAddrPort()),
469  std::bind(&TorController::add_onion_cb, this, std::placeholders::_1, std::placeholders::_2));
470  } else {
471  LogPrintf("tor: Authentication failed\n");
472  }
473 }
474 
491 static std::vector<uint8_t> ComputeResponse(const std::string &key, const std::vector<uint8_t> &cookie, const std::vector<uint8_t> &clientNonce, const std::vector<uint8_t> &serverNonce)
492 {
493  CHMAC_SHA256 computeHash((const uint8_t*)key.data(), key.size());
494  std::vector<uint8_t> computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0);
495  computeHash.Write(cookie.data(), cookie.size());
496  computeHash.Write(clientNonce.data(), clientNonce.size());
497  computeHash.Write(serverNonce.data(), serverNonce.size());
498  computeHash.Finalize(computedHash.data());
499  return computedHash;
500 }
501 
503 {
504  if (reply.code == 250) {
505  LogPrint(BCLog::TOR, "SAFECOOKIE authentication challenge successful\n");
506  std::pair<std::string,std::string> l = SplitTorReplyLine(reply.lines[0]);
507  if (l.first == "AUTHCHALLENGE") {
508  std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
509  if (m.empty()) {
510  LogPrintf("tor: Error parsing AUTHCHALLENGE parameters: %s\n", SanitizeString(l.second));
511  return;
512  }
513  std::vector<uint8_t> serverHash = ParseHex(m["SERVERHASH"]);
514  std::vector<uint8_t> serverNonce = ParseHex(m["SERVERNONCE"]);
515  LogPrint(BCLog::TOR, "AUTHCHALLENGE ServerHash %s ServerNonce %s\n", HexStr(serverHash), HexStr(serverNonce));
516  if (serverNonce.size() != 32) {
517  LogPrintf("tor: ServerNonce is not 32 bytes, as required by spec\n");
518  return;
519  }
520 
521  std::vector<uint8_t> computedServerHash = ComputeResponse(TOR_SAFE_SERVERKEY, cookie, clientNonce, serverNonce);
522  if (computedServerHash != serverHash) {
523  LogPrintf("tor: ServerHash %s does not match expected ServerHash %s\n", HexStr(serverHash), HexStr(computedServerHash));
524  return;
525  }
526 
527  std::vector<uint8_t> computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, cookie, clientNonce, serverNonce);
528  _conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
529  } else {
530  LogPrintf("tor: Invalid reply to AUTHCHALLENGE\n");
531  }
532  } else {
533  LogPrintf("tor: SAFECOOKIE authentication challenge failed\n");
534  }
535 }
536 
538 {
539  if (reply.code == 250) {
540  std::set<std::string> methods;
541  std::string cookiefile;
542  /*
543  * 250-AUTH METHODS=COOKIE,SAFECOOKIE COOKIEFILE="/home/x/.tor/control_auth_cookie"
544  * 250-AUTH METHODS=NULL
545  * 250-AUTH METHODS=HASHEDPASSWORD
546  */
547  for (const std::string &s : reply.lines) {
548  std::pair<std::string,std::string> l = SplitTorReplyLine(s);
549  if (l.first == "AUTH") {
550  std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
551  std::map<std::string,std::string>::iterator i;
552  if ((i = m.find("METHODS")) != m.end()) {
553  std::vector<std::string> m_vec = SplitString(i->second, ',');
554  methods = std::set<std::string>(m_vec.begin(), m_vec.end());
555  }
556  if ((i = m.find("COOKIEFILE")) != m.end())
557  cookiefile = i->second;
558  } else if (l.first == "VERSION") {
559  std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
560  std::map<std::string,std::string>::iterator i;
561  if ((i = m.find("Tor")) != m.end()) {
562  LogPrint(BCLog::TOR, "Connected to Tor version %s\n", i->second);
563  }
564  }
565  }
566  for (const std::string &s : methods) {
567  LogPrint(BCLog::TOR, "Supported authentication method: %s\n", s);
568  }
569  // Prefer NULL, otherwise SAFECOOKIE. If a password is provided, use HASHEDPASSWORD
570  /* Authentication:
571  * cookie: hex-encoded ~/.tor/control_auth_cookie
572  * password: "password"
573  */
574  std::string torpassword = gArgs.GetArg("-torpassword", "");
575  if (!torpassword.empty()) {
576  if (methods.count("HASHEDPASSWORD")) {
577  LogPrint(BCLog::TOR, "Using HASHEDPASSWORD authentication\n");
578  ReplaceAll(torpassword, "\"", "\\\"");
579  _conn.Command("AUTHENTICATE \"" + torpassword + "\"", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
580  } else {
581  LogPrintf("tor: Password provided with -torpassword, but HASHEDPASSWORD authentication is not available\n");
582  }
583  } else if (methods.count("NULL")) {
584  LogPrint(BCLog::TOR, "Using NULL authentication\n");
585  _conn.Command("AUTHENTICATE", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
586  } else if (methods.count("SAFECOOKIE")) {
587  // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie
588  LogPrint(BCLog::TOR, "Using SAFECOOKIE authentication, reading cookie authentication from %s\n", cookiefile);
589  std::pair<bool,std::string> status_cookie = ReadBinaryFile(fs::PathFromString(cookiefile), TOR_COOKIE_SIZE);
590  if (status_cookie.first && status_cookie.second.size() == TOR_COOKIE_SIZE) {
591  // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
592  cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
593  clientNonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
595  _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce), std::bind(&TorController::authchallenge_cb, this, std::placeholders::_1, std::placeholders::_2));
596  } else {
597  if (status_cookie.first) {
598  LogPrintf("tor: Authentication cookie %s is not exactly %i bytes, as is required by the spec\n", cookiefile, TOR_COOKIE_SIZE);
599  } else {
600  LogPrintf("tor: Authentication cookie %s could not be opened (check permissions)\n", cookiefile);
601  }
602  }
603  } else if (methods.count("HASHEDPASSWORD")) {
604  LogPrintf("tor: The only supported authentication mechanism left is password, but no password provided with -torpassword\n");
605  } else {
606  LogPrintf("tor: No supported authentication method\n");
607  }
608  } else {
609  LogPrintf("tor: Requesting protocol info failed\n");
610  }
611 }
612 
614 {
616  // First send a PROTOCOLINFO command to figure out what authentication is expected
617  if (!_conn.Command("PROTOCOLINFO 1", std::bind(&TorController::protocolinfo_cb, this, std::placeholders::_1, std::placeholders::_2)))
618  LogPrintf("tor: Error sending initial protocolinfo command\n");
619 }
620 
622 {
623  // Stop advertising service when disconnected
624  if (service.IsValid())
626  service = CService();
627  if (!reconnect)
628  return;
629 
630  LogPrint(BCLog::TOR, "Not connected to Tor control port %s, trying to reconnect\n", m_tor_control_center);
631 
632  // Single-shot timer for reconnect. Use exponential backoff.
633  struct timeval time = MillisToTimeval(int64_t(reconnect_timeout * 1000.0));
634  if (reconnect_ev)
635  event_add(reconnect_ev, &time);
637 }
638 
640 {
641  /* Try to reconnect and reestablish if we get booted - for example, Tor
642  * may be restarting.
643  */
644  if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
645  std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
646  LogPrintf("tor: Re-initiating connection to Tor control port %s failed\n", m_tor_control_center);
647  }
648 }
649 
651 {
652  return gArgs.GetDataDirNet() / "onion_v3_private_key";
653 }
654 
655 void TorController::reconnect_cb(evutil_socket_t fd, short what, void *arg)
656 {
657  TorController *self = static_cast<TorController*>(arg);
658  self->Reconnect();
659 }
660 
661 /****** Thread ********/
662 static struct event_base *gBase;
663 static std::thread torControlThread;
664 
665 static void TorControlThread(CService onion_service_target)
666 {
667  TorController ctrl(gBase, gArgs.GetArg("-torcontrol", DEFAULT_TOR_CONTROL), onion_service_target);
668 
669  event_base_dispatch(gBase);
670 }
671 
672 void StartTorControl(CService onion_service_target)
673 {
674  assert(!gBase);
675 #ifdef WIN32
676  evthread_use_windows_threads();
677 #else
678  evthread_use_pthreads();
679 #endif
680  gBase = event_base_new();
681  if (!gBase) {
682  LogPrintf("tor: Unable to create event_base\n");
683  return;
684  }
685 
686  torControlThread = std::thread(&util::TraceThread, "torcontrol", [onion_service_target] {
687  TorControlThread(onion_service_target);
688  });
689 }
690 
692 {
693  if (gBase) {
694  LogPrintf("tor: Thread interrupt\n");
695  event_base_once(gBase, -1, EV_TIMEOUT, [](evutil_socket_t, short, void*) {
696  event_base_loopbreak(gBase);
697  }, nullptr, nullptr);
698  }
699 }
700 
702 {
703  if (gBase) {
704  torControlThread.join();
705  event_base_free(gBase);
706  gBase = nullptr;
707  }
708 }
709 
711 {
712  struct in_addr onion_service_target;
713  onion_service_target.s_addr = htonl(INADDR_LOOPBACK);
714  return {onion_service_target, BaseParams().OnionServiceTargetPort()};
715 }
ArgsManager gArgs
Definition: args.cpp:41
const auto cmd
const CChainParams & Params()
Return the currently selected parameters.
const CBaseChainParams & BaseParams()
Return the currently selected parameters.
#define Assume(val)
Assume is the identity function.
Definition: check.h:89
std::vector< std::string > GetArgs(const std::string &strArg) const
Return a vector of strings of the given argument.
Definition: args.cpp:360
fs::path GetDataDirNet() const
Get data directory path with appended network identifier.
Definition: args.h:232
bool IsArgSet(const std::string &strArg) const
Return true if the given argument has been manually set.
Definition: args.cpp:369
std::string GetArg(const std::string &strArg, const std::string &strDefault) const
Return string argument or default value.
Definition: args.cpp:455
uint16_t OnionServiceTargetPort() const
A hasher class for HMAC-SHA-256.
Definition: hmac_sha256.h:15
void Finalize(unsigned char hash[OUTPUT_SIZE])
Definition: hmac_sha256.cpp:29
CHMAC_SHA256 & Write(const unsigned char *data, size_t len)
Definition: hmac_sha256.h:24
static const size_t OUTPUT_SIZE
Definition: hmac_sha256.h:21
bool IsValid() const
Definition: netaddress.cpp:425
A combination of a network address (CNetAddr) and a (TCP) port.
Definition: netaddress.h:531
std::string ToStringAddrPort() const
Definition: netaddress.cpp:902
Definition: netbase.h:59
void Add(Network net) EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
Definition: netbase.h:103
Low-level handling for Tor control connection.
Definition: torcontrol.h:52
std::deque< ReplyHandlerCB > reply_handlers
Response handlers.
Definition: torcontrol.h:94
bool Connect(const std::string &tor_control_center, const ConnectionCB &connected, const ConnectionCB &disconnected)
Connect to a Tor control port.
Definition: torcontrol.cpp:141
TorControlConnection(struct event_base *base)
Create a new TorControlConnection.
Definition: torcontrol.cpp:68
bool Command(const std::string &cmd, const ReplyHandlerCB &reply_handler)
Send a command, register a handler for the reply.
Definition: torcontrol.cpp:185
std::function< void(TorControlConnection &)> connected
Callback when ready for use.
Definition: torcontrol.h:84
static void readcb(struct bufferevent *bev, void *ctx)
Libevent handlers: internal.
Definition: torcontrol.cpp:79
std::function< void(TorControlConnection &, const TorControlReply &)> ReplyHandlerCB
Definition: torcontrol.h:55
static void eventcb(struct bufferevent *bev, short what, void *ctx)
Definition: torcontrol.cpp:124
std::function< void(TorControlConnection &)> disconnected
Callback when connection lost.
Definition: torcontrol.h:86
std::function< void(TorControlConnection &)> ConnectionCB
Definition: torcontrol.h:54
void Disconnect()
Disconnect from Tor control port.
Definition: torcontrol.cpp:178
struct bufferevent * b_conn
Connection to control socket.
Definition: torcontrol.h:90
struct event_base * base
Libevent event base.
Definition: torcontrol.h:88
Reply from Tor, can be single or multi-line.
Definition: torcontrol.h:34
std::vector< std::string > lines
Definition: torcontrol.h:39
Controller that connects to Tor control socket, authenticate, then create and maintain an ephemeral o...
Definition: torcontrol.h:107
TorControlConnection conn
Definition: torcontrol.h:123
static void reconnect_cb(evutil_socket_t fd, short what, void *arg)
Callback for reconnect timer.
Definition: torcontrol.cpp:655
std::string service_id
Definition: torcontrol.h:125
struct event_base * base
Definition: torcontrol.h:121
fs::path GetPrivateKeyFile()
Get name of file to store private key in.
Definition: torcontrol.cpp:650
std::vector< uint8_t > clientNonce
ClientNonce for SAFECOOKIE auth.
Definition: torcontrol.h:134
void connected_cb(TorControlConnection &conn)
Callback after successful connection.
Definition: torcontrol.cpp:613
void get_socks_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for GETINFO net/listeners/socks result.
Definition: torcontrol.cpp:349
void add_onion_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for ADD_ONION result.
Definition: torcontrol.cpp:416
const std::string m_tor_control_center
Definition: torcontrol.h:122
void disconnected_cb(TorControlConnection &conn)
Callback after connection lost or failed connection attempt.
Definition: torcontrol.cpp:621
const CService m_target
Definition: torcontrol.h:130
void authchallenge_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for AUTHCHALLENGE result.
Definition: torcontrol.cpp:502
CService service
Definition: torcontrol.h:129
std::vector< uint8_t > cookie
Cookie for SAFECOOKIE auth.
Definition: torcontrol.h:132
struct event * reconnect_ev
Definition: torcontrol.h:127
float reconnect_timeout
Definition: torcontrol.h:128
void auth_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for AUTHENTICATE result.
Definition: torcontrol.cpp:451
void Reconnect()
Reconnect, after getting disconnected.
Definition: torcontrol.cpp:639
std::string private_key
Definition: torcontrol.h:124
void protocolinfo_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for PROTOCOLINFO result.
Definition: torcontrol.cpp:537
Path class wrapper to block calls to the fs::path(std::string) implicit constructor and the fs::path:...
Definition: fs.h:33
#define LogPrint(category,...)
Definition: logging.h:264
#define LogInfo(...)
Definition: logging.h:240
#define LogPrintf(...)
Definition: logging.h:245
@ TOR
Definition: logging.h:42
static std::string PathToString(const path &path)
Convert path object to a byte string.
Definition: fs.h:151
static path PathFromString(const std::string &string)
Convert byte string to path object.
Definition: fs.h:174
void TraceThread(std::string_view thread_name, std::function< void()> thread_func)
A wrapper for do-something-once thread functions.
Definition: thread.cpp:16
void RemoveLocal(const CService &addr)
Definition: net.cpp:302
bool AddLocal(const CService &addr_, int nScore)
Definition: net.cpp:269
@ LOCAL_MANUAL
Definition: net.h:153
@ NET_ONION
TOR (v2 or v3)
Definition: netaddress.h:43
std::vector< CService > Lookup(const std::string &name, uint16_t portDefault, bool fAllowLookup, unsigned int nMaxSolutions, DNSLookupFn dns_lookup_function)
Resolve a service string to its corresponding service.
Definition: netbase.cpp:184
bool SetProxy(enum Network net, const Proxy &addrProxy)
Definition: netbase.cpp:669
ReachableNets g_reachable_nets
Definition: netbase.cpp:43
bool fNameLookup
Definition: netbase.cpp:37
CService LookupNumeric(const std::string &name, uint16_t portDefault, DNSLookupFn dns_lookup_function)
Resolve a service string with a numeric IP to its first corresponding service.
Definition: netbase.cpp:209
void GetRandBytes(Span< unsigned char > bytes) noexcept
Overall design of the RNG and entropy sources.
Definition: random.cpp:638
bool WriteBinaryFile(const fs::path &filename, const std::string &data)
Write contents of std::string to a file.
std::pair< bool, std::string > ReadBinaryFile(const fs::path &filename, size_t maxsize)
Read full contents of a file and return them in a std::string.
std::vector< Byte > ParseHex(std::string_view hex_str)
Like TryParseHex, but returns an empty vector on invalid input.
Definition: strencodings.h:65
std::vector< std::string > SplitString(std::string_view str, char sep)
Definition: string.h:21
std::string ToString(const T &t)
Locale-independent version of std::to_string.
Definition: string.h:109
struct timeval MillisToTimeval(int64_t nTimeout)
Convert milliseconds to a struct timeval for e.g.
Definition: time.cpp:125
#define strprintf
Format arguments and return the string or write to given std::ostream (see tinyformat::format doc for...
Definition: tinyformat.h:1162
static const std::string TOR_SAFE_CLIENTKEY
For computing clientHash in SAFECOOKIE.
Definition: torcontrol.cpp:54
CService DefaultOnionServiceTarget()
Definition: torcontrol.cpp:710
static const int MAX_LINE_LENGTH
Maximum length for lines received on TorControlConnection.
Definition: torcontrol.cpp:63
std::pair< std::string, std::string > SplitTorReplyLine(const std::string &s)
Definition: torcontrol.cpp:205
static std::vector< uint8_t > ComputeResponse(const std::string &key, const std::vector< uint8_t > &cookie, const std::vector< uint8_t > &clientNonce, const std::vector< uint8_t > &serverNonce)
Compute Tor SAFECOOKIE response.
Definition: torcontrol.cpp:491
static const float RECONNECT_TIMEOUT_EXP
Exponential backoff configuration - growth factor.
Definition: torcontrol.cpp:58
const std::string DEFAULT_TOR_CONTROL
Default control ip and port.
Definition: torcontrol.cpp:46
static void TorControlThread(CService onion_service_target)
Definition: torcontrol.cpp:665
static const std::string TOR_SAFE_SERVERKEY
For computing serverHash in SAFECOOKIE.
Definition: torcontrol.cpp:52
static const int TOR_COOKIE_SIZE
Tor cookie size (from control-spec.txt)
Definition: torcontrol.cpp:48
static struct event_base * gBase
Definition: torcontrol.cpp:662
static const int TOR_NONCE_SIZE
Size of client/server nonce for SAFECOOKIE.
Definition: torcontrol.cpp:50
void InterruptTorControl()
Definition: torcontrol.cpp:691
static std::thread torControlThread
Definition: torcontrol.cpp:663
static const float RECONNECT_TIMEOUT_START
Exponential backoff configuration - initial timeout in seconds.
Definition: torcontrol.cpp:56
static const uint16_t DEFAULT_TOR_SOCKS_PORT
Definition: torcontrol.cpp:64
void StartTorControl(CService onion_service_target)
Definition: torcontrol.cpp:672
std::map< std::string, std::string > ParseTorReplyMapping(const std::string &s)
Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'.
Definition: torcontrol.cpp:224
void StopTorControl()
Definition: torcontrol.cpp:701
constexpr int DEFAULT_TOR_CONTROL_PORT
Functionality for communicating with Tor.
Definition: torcontrol.h:22
std::string HexStr(const Span< const uint8_t > s)
Convert a span of bytes to a lower-case hexadecimal string.
std::string SanitizeString(std::string_view str, int rule)
Remove unsafe chars.
void ReplaceAll(std::string &in_out, const std::string &search, const std::string &substitute)
Definition: string.cpp:10
assert(!tx.IsCoinBase())