Bitcoin ABC  0.26.3
P2P Digital Currency
torcontrol.cpp
Go to the documentation of this file.
1 // Copyright (c) 2015-2016 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 <compat.h>
11 #include <crypto/hmac_sha256.h>
12 #include <net.h>
13 #include <netaddress.h>
14 #include <netbase.h>
15 #include <util/readwritefile.h>
16 #include <util/strencodings.h>
17 #include <util/string.h>
18 #include <util/system.h>
19 #include <util/thread.h>
20 #include <util/time.h>
21 
22 #include <boost/signals2/signal.hpp>
23 
24 #include <event2/buffer.h>
25 #include <event2/bufferevent.h>
26 #include <event2/event.h>
27 #include <event2/thread.h>
28 #include <event2/util.h>
29 
30 #include <cstdlib>
31 #include <deque>
32 #include <functional>
33 #include <set>
34 #include <vector>
35 
37 const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:9051";
39 static const int TOR_COOKIE_SIZE = 32;
41 static const int TOR_NONCE_SIZE = 32;
43 static const std::string TOR_SAFE_SERVERKEY =
44  "Tor safe cookie authentication server-to-controller hash";
46 static const std::string TOR_SAFE_CLIENTKEY =
47  "Tor safe cookie authentication controller-to-server hash";
49 static const float RECONNECT_TIMEOUT_START = 1.0;
51 static const float RECONNECT_TIMEOUT_EXP = 1.5;
58 static const int MAX_LINE_LENGTH = 100000;
59 
60 /****** Low-level TorControlConnection ********/
61 
64 public:
66 
67  int code;
68  std::vector<std::string> lines;
69 
70  void Clear() {
71  code = 0;
72  lines.clear();
73  }
74 };
75 
81 public:
82  typedef std::function<void(TorControlConnection &)> ConnectionCB;
83  typedef std::function<void(TorControlConnection &, const TorControlReply &)>
85 
88  explicit TorControlConnection(struct event_base *base);
90 
99  bool Connect(const std::string &tor_control_center,
100  const ConnectionCB &connected,
101  const ConnectionCB &disconnected);
102 
106  void Disconnect();
107 
113  bool Command(const std::string &cmd, const ReplyHandlerCB &reply_handler);
114 
116  boost::signals2::signal<void(TorControlConnection &,
117  const TorControlReply &)>
119 
120 private:
122  std::function<void(TorControlConnection &)> connected;
124  std::function<void(TorControlConnection &)> disconnected;
126  struct event_base *base;
128  struct bufferevent *b_conn;
132  std::deque<ReplyHandlerCB> reply_handlers;
133 
135  static void readcb(struct bufferevent *bev, void *ctx);
136  static void eventcb(struct bufferevent *bev, short what, void *ctx);
137 };
138 
140  : base(_base), b_conn(nullptr) {}
141 
143  if (b_conn) {
144  bufferevent_free(b_conn);
145  }
146 }
147 
148 void TorControlConnection::readcb(struct bufferevent *bev, void *ctx) {
149  TorControlConnection *self = static_cast<TorControlConnection *>(ctx);
150  struct evbuffer *input = bufferevent_get_input(bev);
151  size_t n_read_out = 0;
152  char *line;
153  assert(input);
154  // If there is not a whole line to read, evbuffer_readln returns nullptr
155  while ((line = evbuffer_readln(input, &n_read_out, EVBUFFER_EOL_CRLF)) !=
156  nullptr) {
157  std::string s(line, n_read_out);
158  free(line);
159  // Short line
160  if (s.size() < 4) {
161  continue;
162  }
163  // <status>(-|+| )<data><CRLF>
164  self->message.code = atoi(s.substr(0, 3));
165  self->message.lines.push_back(s.substr(4));
166  // '-','+' or ' '
167  char ch = s[3];
168  if (ch == ' ') {
169  // Final line, dispatch reply and clean up
170  if (self->message.code >= 600) {
171  // Dispatch async notifications to async handler.
172  // Synchronous and asynchronous messages are never interleaved
173  self->async_handler(*self, self->message);
174  } else {
175  if (!self->reply_handlers.empty()) {
176  // Invoke reply handler with message
177  self->reply_handlers.front()(*self, self->message);
178  self->reply_handlers.pop_front();
179  } else {
181  "tor: Received unexpected sync reply %i\n",
182  self->message.code);
183  }
184  }
185  self->message.Clear();
186  }
187  }
188 
189  // Check for size of buffer - protect against memory exhaustion with very
190  // long lines. Do this after evbuffer_readln to make sure all full lines
191  // have been removed from the buffer. Everything left is an incomplete line.
192  if (evbuffer_get_length(input) > MAX_LINE_LENGTH) {
193  LogPrintf("tor: Disconnecting because MAX_LINE_LENGTH exceeded\n");
194  self->Disconnect();
195  }
196 }
197 
198 void TorControlConnection::eventcb(struct bufferevent *bev, short what,
199  void *ctx) {
200  TorControlConnection *self = static_cast<TorControlConnection *>(ctx);
201  if (what & BEV_EVENT_CONNECTED) {
202  LogPrint(BCLog::TOR, "tor: Successfully connected!\n");
203  self->connected(*self);
204  } else if (what & (BEV_EVENT_EOF | BEV_EVENT_ERROR)) {
205  if (what & BEV_EVENT_ERROR) {
207  "tor: Error connecting to Tor control socket\n");
208  } else {
209  LogPrint(BCLog::TOR, "tor: End of stream\n");
210  }
211  self->Disconnect();
212  self->disconnected(*self);
213  }
214 }
215 
216 bool TorControlConnection::Connect(const std::string &tor_control_center,
217  const ConnectionCB &_connected,
218  const ConnectionCB &_disconnected) {
219  if (b_conn) {
220  Disconnect();
221  }
222  // Parse tor_control_center address:port
223  struct sockaddr_storage connect_to_addr;
224  int connect_to_addrlen = sizeof(connect_to_addr);
225  if (evutil_parse_sockaddr_port(tor_control_center.c_str(),
226  (struct sockaddr *)&connect_to_addr,
227  &connect_to_addrlen) < 0) {
228  LogPrintf("tor: Error parsing socket address %s\n", tor_control_center);
229  return false;
230  }
231 
232  // Create a new socket, set up callbacks and enable notification bits
233  b_conn = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE);
234  if (!b_conn) {
235  return false;
236  }
237  bufferevent_setcb(b_conn, TorControlConnection::readcb, nullptr,
239  bufferevent_enable(b_conn, EV_READ | EV_WRITE);
240  this->connected = _connected;
241  this->disconnected = _disconnected;
242 
243  // Finally, connect to tor_control_center
244  if (bufferevent_socket_connect(b_conn, (struct sockaddr *)&connect_to_addr,
245  connect_to_addrlen) < 0) {
246  LogPrintf("tor: Error connecting to address %s\n", tor_control_center);
247  return false;
248  }
249  return true;
250 }
251 
253  if (b_conn) {
254  bufferevent_free(b_conn);
255  }
256  b_conn = nullptr;
257 }
258 
259 bool TorControlConnection::Command(const std::string &cmd,
260  const ReplyHandlerCB &reply_handler) {
261  if (!b_conn) {
262  return false;
263  }
264  struct evbuffer *buf = bufferevent_get_output(b_conn);
265  if (!buf) {
266  return false;
267  }
268  evbuffer_add(buf, cmd.data(), cmd.size());
269  evbuffer_add(buf, "\r\n", 2);
270  reply_handlers.push_back(reply_handler);
271  return true;
272 }
273 
274 /****** General parsing utilities ********/
275 
276 /* Split reply line in the form 'AUTH METHODS=...' into a type
277  * 'AUTH' and arguments 'METHODS=...'.
278  * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
279  * the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24).
280  */
281 std::pair<std::string, std::string> SplitTorReplyLine(const std::string &s) {
282  size_t ptr = 0;
283  std::string type;
284  while (ptr < s.size() && s[ptr] != ' ') {
285  type.push_back(s[ptr]);
286  ++ptr;
287  }
288  if (ptr < s.size()) {
289  // skip ' '
290  ++ptr;
291  }
292  return make_pair(type, s.substr(ptr));
293 }
294 
303 std::map<std::string, std::string> ParseTorReplyMapping(const std::string &s) {
304  std::map<std::string, std::string> mapping;
305  size_t ptr = 0;
306  while (ptr < s.size()) {
307  std::string key, value;
308  while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
309  key.push_back(s[ptr]);
310  ++ptr;
311  }
312  // unexpected end of line
313  if (ptr == s.size()) {
314  return std::map<std::string, std::string>();
315  }
316  // The remaining string is an OptArguments
317  if (s[ptr] == ' ') {
318  break;
319  }
320  // skip '='
321  ++ptr;
322  // Quoted string
323  if (ptr < s.size() && s[ptr] == '"') {
324  // skip opening '"'
325  ++ptr;
326  bool escape_next = false;
327  while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
328  // Repeated backslashes must be interpreted as pairs
329  escape_next = (s[ptr] == '\\' && !escape_next);
330  value.push_back(s[ptr]);
331  ++ptr;
332  }
333  // unexpected end of line
334  if (ptr == s.size()) {
335  return std::map<std::string, std::string>();
336  }
337  // skip closing '"'
338  ++ptr;
351  std::string escaped_value;
352  for (size_t i = 0; i < value.size(); ++i) {
353  if (value[i] == '\\') {
354  // This will always be valid, because if the QuotedString
355  // ended in an odd number of backslashes, then the parser
356  // would already have returned above, due to a missing
357  // terminating double-quote.
358  ++i;
359  if (value[i] == 'n') {
360  escaped_value.push_back('\n');
361  } else if (value[i] == 't') {
362  escaped_value.push_back('\t');
363  } else if (value[i] == 'r') {
364  escaped_value.push_back('\r');
365  } else if ('0' <= value[i] && value[i] <= '7') {
366  size_t j;
367  // Octal escape sequences have a limit of three octal
368  // digits, but terminate at the first character that is
369  // not a valid octal digit if encountered sooner.
370  for (j = 1; j < 3 && (i + j) < value.size() &&
371  '0' <= value[i + j] && value[i + j] <= '7';
372  ++j) {
373  }
374  // Tor restricts first digit to 0-3 for three-digit
375  // octals. A leading digit of 4-7 would therefore be
376  // interpreted as a two-digit octal.
377  if (j == 3 && value[i] > '3') {
378  j--;
379  }
380  escaped_value.push_back(
381  strtol(value.substr(i, j).c_str(), NULL, 8));
382  // Account for automatic incrementing at loop end
383  i += j - 1;
384  } else {
385  escaped_value.push_back(value[i]);
386  }
387  } else {
388  escaped_value.push_back(value[i]);
389  }
390  }
391  value = escaped_value;
392  } else {
393  // Unquoted value. Note that values can contain '=' at will, just no
394  // spaces
395  while (ptr < s.size() && s[ptr] != ' ') {
396  value.push_back(s[ptr]);
397  ++ptr;
398  }
399  }
400  if (ptr < s.size() && s[ptr] == ' ') {
401  // skip ' ' after key=value
402  ++ptr;
403  }
404  mapping[key] = value;
405  }
406  return mapping;
407 }
408 
409 /****** Bitcoin specific TorController implementation ********/
410 
416 public:
417  TorController(struct event_base *base,
418  const std::string &tor_control_center,
419  const CService &target);
420  ~TorController();
421 
424 
426  void Reconnect();
427 
428 private:
429  struct event_base *base;
430  const std::string m_tor_control_center;
432  std::string private_key;
433  std::string service_id;
434  bool reconnect;
435  struct event *reconnect_ev;
440  std::vector<uint8_t> cookie;
442  std::vector<uint8_t> clientNonce;
443 
447  void auth_cb(TorControlConnection &conn, const TorControlReply &reply);
450  const TorControlReply &reply);
453  const TorControlReply &reply);
458 
460  static void reconnect_cb(evutil_socket_t fd, short what, void *arg);
461 };
462 
463 TorController::TorController(struct event_base *_base,
464  const std::string &tor_control_center,
465  const CService &target)
466  : base(_base), m_tor_control_center(tor_control_center), conn(base),
467  reconnect(true), reconnect_ev(0),
468  reconnect_timeout(RECONNECT_TIMEOUT_START), m_target(target) {
469  reconnect_ev = event_new(base, -1, 0, reconnect_cb, this);
470  if (!reconnect_ev) {
471  LogPrintf(
472  "tor: Failed to create event for reconnection: out of memory?\n");
473  }
474  // Start connection attempts immediately
476  std::bind(&TorController::connected_cb, this,
477  std::placeholders::_1),
478  std::bind(&TorController::disconnected_cb, this,
479  std::placeholders::_1))) {
480  LogPrintf("tor: Initiating connection to Tor control port %s failed\n",
482  }
483  // Read service private key if cached
484  std::pair<bool, std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
485  if (pkf.first) {
486  LogPrint(BCLog::TOR, "tor: Reading cached private key from %s\n",
488  private_key = pkf.second;
489  }
490 }
491 
493  if (reconnect_ev) {
494  event_free(reconnect_ev);
495  reconnect_ev = nullptr;
496  }
497  if (service.IsValid()) {
499  }
500 }
501 
503  const TorControlReply &reply) {
504  if (reply.code == 250) {
505  LogPrint(BCLog::TOR, "tor: ADD_ONION successful\n");
506  for (const std::string &s : reply.lines) {
507  std::map<std::string, std::string> m = ParseTorReplyMapping(s);
508  std::map<std::string, std::string>::iterator i;
509  if ((i = m.find("ServiceID")) != m.end()) {
510  service_id = i->second;
511  }
512  if ((i = m.find("PrivateKey")) != m.end()) {
513  private_key = i->second;
514  }
515  }
516  if (service_id.empty()) {
517  LogPrintf("tor: Error parsing ADD_ONION parameters:\n");
518  for (const std::string &s : reply.lines) {
519  LogPrintf(" %s\n", SanitizeString(s));
520  }
521  return;
522  }
523  service = LookupNumeric(std::string(service_id + ".onion"),
524  Params().GetDefaultPort());
525  LogPrintf("tor: Got service ID %s, advertising service %s\n",
528  LogPrint(BCLog::TOR, "tor: Cached service private key to %s\n",
530  } else {
531  LogPrintf("tor: Error writing service private key to %s\n",
533  }
535  // ... onion requested - keep connection open
536  } else if (reply.code == 510) { // 510 Unrecognized command
537  LogPrintf("tor: Add onion failed with unrecognized command (You "
538  "probably need to upgrade Tor)\n");
539  } else {
540  LogPrintf("tor: Add onion failed; error code %d\n", reply.code);
541  }
542 }
543 
545  const TorControlReply &reply) {
546  if (reply.code == 250) {
547  LogPrint(BCLog::TOR, "tor: Authentication successful\n");
548 
549  // Now that we know Tor is running setup the proxy for onion addresses
550  // if -onion isn't set to something else.
551  if (gArgs.GetArg("-onion", "") == "") {
552  CService resolved(LookupNumeric("127.0.0.1", 9050));
553  proxyType addrOnion = proxyType(resolved, true);
554  SetProxy(NET_ONION, addrOnion);
555  SetReachable(NET_ONION, true);
556  }
557 
558  // Finally - now create the service
559  // No private key, generate one
560  if (private_key.empty()) {
561  // Explicitly request key type - see issue #9214
562  private_key = "NEW:ED25519-V3";
563  }
564  // Request onion service, redirect port.
565  // Note that the 'virtual' port doesn't have to be the same as our
566  // internal port, but this is just a convenient choice. TODO; refactor
567  // the shutdown sequence some day.
568  _conn.Command(strprintf("ADD_ONION %s Port=%i,%s", private_key,
571  std::bind(&TorController::add_onion_cb, this,
572  std::placeholders::_1, std::placeholders::_2));
573  } else {
574  LogPrintf("tor: Authentication failed\n");
575  }
576 }
577 
594 static std::vector<uint8_t>
595 ComputeResponse(const std::string &key, const std::vector<uint8_t> &cookie,
596  const std::vector<uint8_t> &clientNonce,
597  const std::vector<uint8_t> &serverNonce) {
598  CHMAC_SHA256 computeHash((const uint8_t *)key.data(), key.size());
599  std::vector<uint8_t> computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0);
600  computeHash.Write(cookie.data(), cookie.size());
601  computeHash.Write(clientNonce.data(), clientNonce.size());
602  computeHash.Write(serverNonce.data(), serverNonce.size());
603  computeHash.Finalize(computedHash.data());
604  return computedHash;
605 }
606 
608  const TorControlReply &reply) {
609  if (reply.code == 250) {
611  "tor: SAFECOOKIE authentication challenge successful\n");
612  std::pair<std::string, std::string> l =
613  SplitTorReplyLine(reply.lines[0]);
614  if (l.first == "AUTHCHALLENGE") {
615  std::map<std::string, std::string> m =
616  ParseTorReplyMapping(l.second);
617  if (m.empty()) {
618  LogPrintf("tor: Error parsing AUTHCHALLENGE parameters: %s\n",
619  SanitizeString(l.second));
620  return;
621  }
622  std::vector<uint8_t> serverHash = ParseHex(m["SERVERHASH"]);
623  std::vector<uint8_t> serverNonce = ParseHex(m["SERVERNONCE"]);
625  "tor: AUTHCHALLENGE ServerHash %s ServerNonce %s\n",
626  HexStr(serverHash), HexStr(serverNonce));
627  if (serverNonce.size() != 32) {
628  LogPrintf(
629  "tor: ServerNonce is not 32 bytes, as required by spec\n");
630  return;
631  }
632 
633  std::vector<uint8_t> computedServerHash = ComputeResponse(
634  TOR_SAFE_SERVERKEY, cookie, clientNonce, serverNonce);
635  if (computedServerHash != serverHash) {
636  LogPrintf("tor: ServerHash %s does not match expected "
637  "ServerHash %s\n",
638  HexStr(serverHash), HexStr(computedServerHash));
639  return;
640  }
641 
642  std::vector<uint8_t> computedClientHash = ComputeResponse(
643  TOR_SAFE_CLIENTKEY, cookie, clientNonce, serverNonce);
644  _conn.Command("AUTHENTICATE " + HexStr(computedClientHash),
645  std::bind(&TorController::auth_cb, this,
646  std::placeholders::_1,
647  std::placeholders::_2));
648  } else {
649  LogPrintf("tor: Invalid reply to AUTHCHALLENGE\n");
650  }
651  } else {
652  LogPrintf("tor: SAFECOOKIE authentication challenge failed\n");
653  }
654 }
655 
657  const TorControlReply &reply) {
658  if (reply.code == 250) {
659  std::set<std::string> methods;
660  std::string cookiefile;
661  /*
662  * 250-AUTH METHODS=COOKIE,SAFECOOKIE
663  * COOKIEFILE="/home/x/.tor/control_auth_cookie"
664  * 250-AUTH METHODS=NULL
665  * 250-AUTH METHODS=HASHEDPASSWORD
666  */
667  for (const std::string &s : reply.lines) {
668  std::pair<std::string, std::string> l = SplitTorReplyLine(s);
669  if (l.first == "AUTH") {
670  std::map<std::string, std::string> m =
671  ParseTorReplyMapping(l.second);
672  std::map<std::string, std::string>::iterator i;
673  if ((i = m.find("METHODS")) != m.end()) {
674  std::vector<std::string> m_vec =
675  SplitString(i->second, ',');
676  methods = std::set<std::string>(m_vec.begin(), m_vec.end());
677  }
678  if ((i = m.find("COOKIEFILE")) != m.end()) {
679  cookiefile = i->second;
680  }
681  } else if (l.first == "VERSION") {
682  std::map<std::string, std::string> m =
683  ParseTorReplyMapping(l.second);
684  std::map<std::string, std::string>::iterator i;
685  if ((i = m.find("Tor")) != m.end()) {
686  LogPrint(BCLog::TOR, "tor: Connected to Tor version %s\n",
687  i->second);
688  }
689  }
690  }
691  for (const std::string &s : methods) {
692  LogPrint(BCLog::TOR, "tor: Supported authentication method: %s\n",
693  s);
694  }
695  // Prefer NULL, otherwise SAFECOOKIE. If a password is provided, use
696  // HASHEDPASSWORD
697  /* Authentication:
698  * cookie: hex-encoded ~/.tor/control_auth_cookie
699  * password: "password"
700  */
701  std::string torpassword = gArgs.GetArg("-torpassword", "");
702  if (!torpassword.empty()) {
703  if (methods.count("HASHEDPASSWORD")) {
705  "tor: Using HASHEDPASSWORD authentication\n");
706  ReplaceAll(torpassword, "\"", "\\\"");
707  _conn.Command("AUTHENTICATE \"" + torpassword + "\"",
708  std::bind(&TorController::auth_cb, this,
709  std::placeholders::_1,
710  std::placeholders::_2));
711  } else {
712  LogPrintf("tor: Password provided with -torpassword, but "
713  "HASHEDPASSWORD authentication is not available\n");
714  }
715  } else if (methods.count("NULL")) {
716  LogPrint(BCLog::TOR, "tor: Using NULL authentication\n");
717  _conn.Command("AUTHENTICATE", std::bind(&TorController::auth_cb,
718  this, std::placeholders::_1,
719  std::placeholders::_2));
720  } else if (methods.count("SAFECOOKIE")) {
721  // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie
723  "tor: Using SAFECOOKIE authentication, "
724  "reading cookie authentication from %s\n",
725  cookiefile);
726  std::pair<bool, std::string> status_cookie =
728  if (status_cookie.first &&
729  status_cookie.second.size() == TOR_COOKIE_SIZE) {
730  // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second),
731  // std::bind(&TorController::auth_cb, this,
732  // std::placeholders::_1, std::placeholders::_2));
733  cookie = std::vector<uint8_t>(status_cookie.second.begin(),
734  status_cookie.second.end());
735  clientNonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
737  _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce),
738  std::bind(&TorController::authchallenge_cb, this,
739  std::placeholders::_1,
740  std::placeholders::_2));
741  } else {
742  if (status_cookie.first) {
743  LogPrintf("tor: Authentication cookie %s is not exactly %i "
744  "bytes, as is required by the spec\n",
745  cookiefile, TOR_COOKIE_SIZE);
746  } else {
747  LogPrintf("tor: Authentication cookie %s could not be "
748  "opened (check permissions)\n",
749  cookiefile);
750  }
751  }
752  } else if (methods.count("HASHEDPASSWORD")) {
753  LogPrintf("tor: The only supported authentication mechanism left "
754  "is password, but no password provided with "
755  "-torpassword\n");
756  } else {
757  LogPrintf("tor: No supported authentication method\n");
758  }
759  } else {
760  LogPrintf("tor: Requesting protocol info failed\n");
761  }
762 }
763 
766  // First send a PROTOCOLINFO command to figure out what authentication is
767  // expected
768  if (!_conn.Command("PROTOCOLINFO 1",
769  std::bind(&TorController::protocolinfo_cb, this,
770  std::placeholders::_1,
771  std::placeholders::_2))) {
772  LogPrintf("tor: Error sending initial protocolinfo command\n");
773  }
774 }
775 
777  // Stop advertising service when disconnected
778  if (service.IsValid()) {
780  }
781  service = CService();
782  if (!reconnect) {
783  return;
784  }
785 
787  "tor: Not connected to Tor control port %s, trying to reconnect\n",
789 
790  // Single-shot timer for reconnect. Use exponential backoff.
791  struct timeval time = MillisToTimeval(int64_t(reconnect_timeout * 1000.0));
792  if (reconnect_ev) {
793  event_add(reconnect_ev, &time);
794  }
796 }
797 
799  /* Try to reconnect and reestablish if we get booted - for example, Tor may
800  * be restarting.
801  */
803  std::bind(&TorController::connected_cb, this,
804  std::placeholders::_1),
805  std::bind(&TorController::disconnected_cb, this,
806  std::placeholders::_1))) {
807  LogPrintf(
808  "tor: Re-initiating connection to Tor control port %s failed\n",
810  }
811 }
812 
814  return gArgs.GetDataDirNet() / "onion_v3_private_key";
815 }
816 
817 void TorController::reconnect_cb(evutil_socket_t fd, short what, void *arg) {
818  TorController *self = static_cast<TorController *>(arg);
819  self->Reconnect();
820 }
821 
822 /****** Thread ********/
823 static struct event_base *gBase;
824 static std::thread torControlThread;
825 
826 static void TorControlThread(CService onion_service_target) {
827  TorController ctrl(gBase, gArgs.GetArg("-torcontrol", DEFAULT_TOR_CONTROL),
828  onion_service_target);
829 
830  event_base_dispatch(gBase);
831 }
832 
833 void StartTorControl(CService onion_service_target) {
834  assert(!gBase);
835 #ifdef WIN32
836  evthread_use_windows_threads();
837 #else
838  evthread_use_pthreads();
839 #endif
840  gBase = event_base_new();
841  if (!gBase) {
842  LogPrintf("tor: Unable to create event_base\n");
843  return;
844  }
845 
847  std::thread(&util::TraceThread, "torcontrol", [onion_service_target] {
848  TorControlThread(onion_service_target);
849  });
850 }
851 
853  if (gBase) {
854  LogPrintf("tor: Thread interrupt\n");
855  event_base_once(
856  gBase, -1, EV_TIMEOUT,
857  [](evutil_socket_t, short, void *) { event_base_loopbreak(gBase); },
858  nullptr, nullptr);
859  }
860 }
861 
863  if (gBase) {
864  torControlThread.join();
865  event_base_free(gBase);
866  gBase = nullptr;
867  }
868 }
869 
871  struct in_addr onion_service_target;
872  onion_service_target.s_addr = htonl(INADDR_LOOPBACK);
873  return {onion_service_target, BaseParams().OnionServiceTargetPort()};
874 }
secp256k1_context * ctx
const CChainParams & Params()
Return the currently selected parameters.
const CBaseChainParams & BaseParams()
Return the currently selected parameters.
const fs::path & GetDataDirNet() const
Get data directory path with appended network identifier.
Definition: system.h:268
std::string GetArg(const std::string &strArg, const std::string &strDefault) const
Return string argument or default value.
Definition: system.cpp:603
uint16_t OnionServiceTargetPort() const
A hasher class for HMAC-SHA-256.
Definition: hmac_sha256.h:14
CHMAC_SHA256 & Write(const uint8_t *data, size_t len)
Definition: hmac_sha256.h:23
static const size_t OUTPUT_SIZE
Definition: hmac_sha256.h:20
void Finalize(uint8_t hash[OUTPUT_SIZE])
Definition: hmac_sha256.cpp:30
bool IsValid() const
Definition: netaddress.cpp:479
A combination of a network address (CNetAddr) and a (TCP) port.
Definition: netaddress.h:545
std::string ToStringIPPort() const
std::string ToString() const
Low-level handling for Tor control connection.
Definition: torcontrol.cpp:80
TorControlReply message
Message being received.
Definition: torcontrol.cpp:130
std::deque< ReplyHandlerCB > reply_handlers
Response handlers.
Definition: torcontrol.cpp:132
bool Connect(const std::string &tor_control_center, const ConnectionCB &connected, const ConnectionCB &disconnected)
Connect to a Tor control port.
Definition: torcontrol.cpp:216
TorControlConnection(struct event_base *base)
Create a new TorControlConnection.
Definition: torcontrol.cpp:139
bool Command(const std::string &cmd, const ReplyHandlerCB &reply_handler)
Send a command, register a handler for the reply.
Definition: torcontrol.cpp:259
std::function< void(TorControlConnection &)> connected
Callback when ready for use.
Definition: torcontrol.cpp:122
boost::signals2::signal< void(TorControlConnection &, const TorControlReply &)> async_handler
Response handlers for async replies.
Definition: torcontrol.cpp:118
static void readcb(struct bufferevent *bev, void *ctx)
Libevent handlers: internal.
Definition: torcontrol.cpp:148
std::function< void(TorControlConnection &)> disconnected
Callback when connection lost.
Definition: torcontrol.cpp:124
static void eventcb(struct bufferevent *bev, short what, void *ctx)
Definition: torcontrol.cpp:198
std::function< void(TorControlConnection &, const TorControlReply &)> ReplyHandlerCB
Definition: torcontrol.cpp:84
void Disconnect()
Disconnect from Tor control port.
Definition: torcontrol.cpp:252
struct bufferevent * b_conn
Connection to control socket.
Definition: torcontrol.cpp:128
struct event_base * base
Libevent event base.
Definition: torcontrol.cpp:126
std::function< void(TorControlConnection &)> ConnectionCB
Definition: torcontrol.cpp:82
Reply from Tor, can be single or multi-line.
Definition: torcontrol.cpp:63
std::vector< std::string > lines
Definition: torcontrol.cpp:68
Controller that connects to Tor control socket, authenticate, then create and maintain an ephemeral o...
Definition: torcontrol.cpp:415
TorControlConnection conn
Definition: torcontrol.cpp:431
static void reconnect_cb(evutil_socket_t fd, short what, void *arg)
Callback for reconnect timer.
Definition: torcontrol.cpp:817
std::string service_id
Definition: torcontrol.cpp:433
struct event_base * base
Definition: torcontrol.cpp:429
fs::path GetPrivateKeyFile()
Get name fo file to store private key in.
Definition: torcontrol.cpp:813
std::vector< uint8_t > clientNonce
ClientNonce for SAFECOOKIE auth.
Definition: torcontrol.cpp:442
void connected_cb(TorControlConnection &conn)
Callback after successful connection.
Definition: torcontrol.cpp:764
void add_onion_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for ADD_ONION result.
Definition: torcontrol.cpp:502
const std::string m_tor_control_center
Definition: torcontrol.cpp:430
void disconnected_cb(TorControlConnection &conn)
Callback after connection lost or failed connection attempt.
Definition: torcontrol.cpp:776
const CService m_target
Definition: torcontrol.cpp:438
void authchallenge_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for AUTHCHALLENGE result.
Definition: torcontrol.cpp:607
CService service
Definition: torcontrol.cpp:437
std::vector< uint8_t > cookie
Cookie for SAFECOOKIE auth.
Definition: torcontrol.cpp:440
struct event * reconnect_ev
Definition: torcontrol.cpp:435
TorController(struct event_base *base, const std::string &tor_control_center, const CService &target)
Definition: torcontrol.cpp:463
float reconnect_timeout
Definition: torcontrol.cpp:436
void auth_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for AUTHENTICATE result.
Definition: torcontrol.cpp:544
void Reconnect()
Reconnect, after getting disconnected.
Definition: torcontrol.cpp:798
std::string private_key
Definition: torcontrol.cpp:432
void protocolinfo_cb(TorControlConnection &conn, const TorControlReply &reply)
Callback for PROTOCOLINFO result.
Definition: torcontrol.cpp:656
Path class wrapper to block calls to the fs::path(std::string) implicit constructor and the fs::path:...
Definition: fs.h:30
#define LogPrint(category,...)
Definition: logging.h:210
#define LogPrintf(...)
Definition: logging.h:206
@ TOR
Definition: logging.h:41
static std::string PathToString(const path &path)
Convert path object to byte string.
Definition: fs.h:142
static path PathFromString(const std::string &string)
Convert byte string to path object.
Definition: fs.h:165
void TraceThread(const char *thread_name, std::function< void()> thread_func)
A wrapper for do-something-once thread functions.
Definition: thread.cpp:13
void RemoveLocal(const CService &addr)
Definition: net.cpp:310
void SetReachable(enum Network net, bool reachable)
Mark a network as reachable or unreachable (no automatic connects to it)
Definition: net.cpp:316
bool AddLocal(const CService &addr, int nScore)
Definition: net.cpp:277
@ LOCAL_MANUAL
Definition: net.h:242
@ NET_ONION
TOR (v2 or v3)
Definition: netaddress.h:56
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:260
bool SetProxy(enum Network net, const proxyType &addrProxy)
Definition: netbase.cpp:710
void GetRandBytes(Span< uint8_t > bytes) noexcept
Overall design of the RNG and entropy sources.
Definition: random.cpp:639
std::pair< bool, std::string > ReadBinaryFile(const fs::path &filename, size_t maxsize=std::numeric_limits< size_t >::max())
Read full contents of a file and return them in a std::string.
bool WriteBinaryFile(const fs::path &filename, const std::string &data)
Write contents of std::string to a file.
static uint16_t GetDefaultPort()
Definition: bitcoin.h:18
std::string HexStr(const Span< const uint8_t > s)
Convert a span of bytes to a lower-case hexadecimal string.
std::string SanitizeString(const std::string &str, int rule)
Remove unsafe chars.
int atoi(const std::string &str)
std::vector< uint8_t > ParseHex(const char *psz)
void ReplaceAll(std::string &in_out, const std::string &search, const std::string &substitute)
Definition: string.cpp:10
std::vector< std::string > SplitString(std::string_view str, char sep)
Definition: string.h:23
ArgsManager gArgs
Definition: system.cpp:80
struct timeval MillisToTimeval(int64_t nTimeout)
Convert milliseconds to a struct timeval for e.g.
Definition: time.cpp:158
#define strprintf
Format arguments and return the string or write to given std::ostream (see tinyformat::format doc for...
Definition: tinyformat.h:1202
static const std::string TOR_SAFE_CLIENTKEY
For computing clientHash in SAFECOOKIE.
Definition: torcontrol.cpp:46
CService DefaultOnionServiceTarget()
Definition: torcontrol.cpp:870
static const int MAX_LINE_LENGTH
Maximum length for lines received on TorControlConnection.
Definition: torcontrol.cpp:58
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:595
static const float RECONNECT_TIMEOUT_EXP
Exponential backoff configuration - growth factor.
Definition: torcontrol.cpp:51
const std::string DEFAULT_TOR_CONTROL
Default control port.
Definition: torcontrol.cpp:37
static void TorControlThread(CService onion_service_target)
Definition: torcontrol.cpp:826
static const std::string TOR_SAFE_SERVERKEY
For computing serverHash in SAFECOOKIE.
Definition: torcontrol.cpp:43
static const int TOR_COOKIE_SIZE
Tor cookie size (from control-spec.txt)
Definition: torcontrol.cpp:39
static struct event_base * gBase
Definition: torcontrol.cpp:823
static const int TOR_NONCE_SIZE
Size of client/server nonce for SAFECOOKIE.
Definition: torcontrol.cpp:41
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:303
void InterruptTorControl()
Definition: torcontrol.cpp:852
static std::thread torControlThread
Definition: torcontrol.cpp:824
std::pair< std::string, std::string > SplitTorReplyLine(const std::string &s)
Definition: torcontrol.cpp:281
static const float RECONNECT_TIMEOUT_START
Exponential backoff configuration - initial timeout in seconds.
Definition: torcontrol.cpp:49
void StartTorControl(CService onion_service_target)
Definition: torcontrol.cpp:833
void StopTorControl()
Definition: torcontrol.cpp:862
assert(!tx.IsCoinBase())