Line data Source code
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 2 : #include <random.h>
18 2 : #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 :
45 : /** Default control ip and port */
46 2 : const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT);
47 : /** Tor cookie size (from control-spec.txt) */
48 : static const int TOR_COOKIE_SIZE = 32;
49 : /** Size of client/server nonce for SAFECOOKIE */
50 : static const int TOR_NONCE_SIZE = 32;
51 : /** For computing serverHash in SAFECOOKIE */
52 2 : static const std::string TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash";
53 : /** For computing clientHash in SAFECOOKIE */
54 2 : static const std::string TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash";
55 : /** Exponential backoff configuration - initial timeout in seconds */
56 : static const float RECONNECT_TIMEOUT_START = 1.0;
57 : /** Exponential backoff configuration - growth factor */
58 : static const float RECONNECT_TIMEOUT_EXP = 1.5;
59 : /** Maximum length for lines received on TorControlConnection.
60 : * tor-control-spec.txt mentions that there is explicitly no limit defined to line length,
61 : * this is belt-and-suspenders sanity limit to prevent memory exhaustion.
62 : */
63 : static const int MAX_LINE_LENGTH = 100000;
64 : static const uint16_t DEFAULT_TOR_SOCKS_PORT = 9050;
65 :
66 : /****** Low-level TorControlConnection ********/
67 :
68 0 : TorControlConnection::TorControlConnection(struct event_base* _base)
69 0 : : base(_base)
70 : {
71 0 : }
72 :
73 0 : TorControlConnection::~TorControlConnection()
74 2 : {
75 0 : if (b_conn)
76 0 : bufferevent_free(b_conn);
77 0 : }
78 :
79 0 : void TorControlConnection::readcb(struct bufferevent *bev, void *ctx)
80 : {
81 0 : TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
82 0 : struct evbuffer *input = bufferevent_get_input(bev);
83 2 : size_t n_read_out = 0;
84 : char *line;
85 0 : assert(input);
86 : // If there is not a whole line to read, evbuffer_readln returns nullptr
87 0 : while((line = evbuffer_readln(input, &n_read_out, EVBUFFER_EOL_CRLF)) != nullptr)
88 : {
89 0 : std::string s(line, n_read_out);
90 0 : free(line);
91 0 : if (s.size() < 4) // Short line
92 0 : continue;
93 : // <status>(-|+| )<data><CRLF>
94 0 : self->message.code = ToIntegral<int>(s.substr(0, 3)).value_or(0);
95 0 : self->message.lines.push_back(s.substr(4));
96 0 : char ch = s[3]; // '-','+' or ' '
97 0 : if (ch == ' ') {
98 : // Final line, dispatch reply and clean up
99 0 : if (self->message.code >= 600) {
100 : // (currently unused)
101 : // Dispatch async notifications to async handler
102 : // Synchronous and asynchronous messages are never interleaved
103 0 : } else {
104 0 : if (!self->reply_handlers.empty()) {
105 : // Invoke reply handler with message
106 0 : self->reply_handlers.front()(*self, self->message);
107 0 : self->reply_handlers.pop_front();
108 0 : } else {
109 0 : LogPrint(BCLog::TOR, "Received unexpected sync reply %i\n", self->message.code);
110 : }
111 : }
112 0 : self->message.Clear();
113 0 : }
114 0 : }
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 0 : if (evbuffer_get_length(input) > MAX_LINE_LENGTH) {
119 0 : LogPrintf("tor: Disconnecting because MAX_LINE_LENGTH exceeded\n");
120 0 : self->Disconnect();
121 0 : }
122 0 : }
123 :
124 0 : void TorControlConnection::eventcb(struct bufferevent *bev, short what, void *ctx)
125 : {
126 0 : TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
127 0 : if (what & BEV_EVENT_CONNECTED) {
128 0 : LogPrint(BCLog::TOR, "Successfully connected!\n");
129 0 : self->connected(*self);
130 0 : } else if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
131 0 : if (what & BEV_EVENT_ERROR) {
132 0 : LogPrint(BCLog::TOR, "Error connecting to Tor control socket\n");
133 0 : } else {
134 0 : LogPrint(BCLog::TOR, "End of stream\n");
135 : }
136 0 : self->Disconnect();
137 0 : self->disconnected(*self);
138 0 : }
139 0 : }
140 :
141 0 : bool TorControlConnection::Connect(const std::string& tor_control_center, const ConnectionCB& _connected, const ConnectionCB& _disconnected)
142 : {
143 0 : if (b_conn) {
144 0 : Disconnect();
145 0 : }
146 :
147 0 : const std::optional<CService> control_service{Lookup(tor_control_center, DEFAULT_TOR_CONTROL_PORT, fNameLookup)};
148 0 : if (!control_service.has_value()) {
149 0 : LogPrintf("tor: Failed to look up control center %s\n", tor_control_center);
150 0 : return false;
151 : }
152 :
153 : struct sockaddr_storage control_address;
154 0 : socklen_t control_address_len = sizeof(control_address);
155 0 : if (!control_service.value().GetSockAddr(reinterpret_cast<struct sockaddr*>(&control_address), &control_address_len)) {
156 0 : LogPrintf("tor: Error parsing socket address %s\n", tor_control_center);
157 0 : return false;
158 : }
159 :
160 : // Create a new socket, set up callbacks and enable notification bits
161 0 : b_conn = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE);
162 0 : if (!b_conn) {
163 0 : return false;
164 : }
165 0 : bufferevent_setcb(b_conn, TorControlConnection::readcb, nullptr, TorControlConnection::eventcb, this);
166 0 : bufferevent_enable(b_conn, EV_READ|EV_WRITE);
167 0 : this->connected = _connected;
168 0 : this->disconnected = _disconnected;
169 :
170 : // Finally, connect to tor_control_center
171 0 : if (bufferevent_socket_connect(b_conn, reinterpret_cast<struct sockaddr*>(&control_address), control_address_len) < 0) {
172 0 : LogPrintf("tor: Error connecting to address %s\n", tor_control_center);
173 0 : return false;
174 : }
175 0 : return true;
176 0 : }
177 :
178 0 : void TorControlConnection::Disconnect()
179 : {
180 0 : if (b_conn)
181 0 : bufferevent_free(b_conn);
182 0 : b_conn = nullptr;
183 0 : }
184 :
185 0 : bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler)
186 : {
187 0 : if (!b_conn)
188 0 : return false;
189 0 : struct evbuffer *buf = bufferevent_get_output(b_conn);
190 0 : if (!buf)
191 0 : return false;
192 0 : evbuffer_add(buf, cmd.data(), cmd.size());
193 0 : evbuffer_add(buf, "\r\n", 2);
194 0 : reply_handlers.push_back(reply_handler);
195 0 : return true;
196 0 : }
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 0 : std::pair<std::string,std::string> SplitTorReplyLine(const std::string &s)
206 : {
207 0 : size_t ptr=0;
208 0 : std::string type;
209 0 : while (ptr < s.size() && s[ptr] != ' ') {
210 0 : type.push_back(s[ptr]);
211 0 : ++ptr;
212 : }
213 0 : if (ptr < s.size())
214 0 : ++ptr; // skip ' '
215 0 : return make_pair(type, s.substr(ptr));
216 0 : }
217 :
218 : /** Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'.
219 : * Returns a map of keys to values, or an empty map if there was an error.
220 : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
221 : * the server reply formats for PROTOCOLINFO (S3.21), AUTHCHALLENGE (S3.24),
222 : * and ADD_ONION (S3.27). See also sections 2.1 and 2.3.
223 : */
224 0 : std::map<std::string,std::string> ParseTorReplyMapping(const std::string &s)
225 : {
226 0 : std::map<std::string,std::string> mapping;
227 0 : size_t ptr=0;
228 0 : while (ptr < s.size()) {
229 0 : std::string key, value;
230 0 : while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
231 0 : key.push_back(s[ptr]);
232 0 : ++ptr;
233 : }
234 0 : if (ptr == s.size()) // unexpected end of line
235 0 : return std::map<std::string,std::string>();
236 0 : if (s[ptr] == ' ') // The remaining string is an OptArguments
237 0 : break;
238 0 : ++ptr; // skip '='
239 0 : if (ptr < s.size() && s[ptr] == '"') { // Quoted string
240 0 : ++ptr; // skip opening '"'
241 0 : bool escape_next = false;
242 0 : while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
243 : // Repeated backslashes must be interpreted as pairs
244 0 : escape_next = (s[ptr] == '\\' && !escape_next);
245 0 : value.push_back(s[ptr]);
246 0 : ++ptr;
247 : }
248 0 : if (ptr == s.size()) // unexpected end of line
249 0 : return std::map<std::string,std::string>();
250 0 : ++ptr; // skip closing '"'
251 : /**
252 : * Unescape value. Per https://spec.torproject.org/control-spec section 2.1.1:
253 : *
254 : * For future-proofing, controller implementors MAY use the following
255 : * rules to be compatible with buggy Tor implementations and with
256 : * future ones that implement the spec as intended:
257 : *
258 : * Read \n \t \r and \0 ... \377 as C escapes.
259 : * Treat a backslash followed by any other character as that character.
260 : */
261 0 : std::string escaped_value;
262 0 : for (size_t i = 0; i < value.size(); ++i) {
263 0 : 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 0 : ++i;
269 0 : if (value[i] == 'n') {
270 0 : escaped_value.push_back('\n');
271 0 : } else if (value[i] == 't') {
272 0 : escaped_value.push_back('\t');
273 0 : } else if (value[i] == 'r') {
274 0 : escaped_value.push_back('\r');
275 0 : } 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 0 : 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 0 : if (j == 3 && value[i] > '3') {
285 0 : j--;
286 0 : }
287 0 : const auto end{i + j};
288 0 : uint8_t val{0};
289 0 : while (i < end) {
290 0 : val *= 8;
291 0 : val += value[i++] - '0';
292 : }
293 0 : escaped_value.push_back(char(val));
294 : // Account for automatic incrementing at loop end
295 0 : --i;
296 0 : } else {
297 0 : escaped_value.push_back(value[i]);
298 : }
299 0 : } else {
300 0 : escaped_value.push_back(value[i]);
301 : }
302 0 : }
303 0 : value = escaped_value;
304 0 : } else { // Unquoted value. Note that values can contain '=' at will, just no spaces
305 0 : while (ptr < s.size() && s[ptr] != ' ') {
306 0 : value.push_back(s[ptr]);
307 0 : ++ptr;
308 : }
309 : }
310 0 : if (ptr < s.size() && s[ptr] == ' ')
311 0 : ++ptr; // skip ' ' after key=value
312 0 : mapping[key] = value;
313 0 : }
314 0 : return mapping;
315 0 : }
316 :
317 0 : TorController::TorController(struct event_base* _base, const std::string& tor_control_center, const CService& target):
318 0 : base(_base),
319 0 : m_tor_control_center(tor_control_center), conn(base), reconnect(true), reconnect_timeout(RECONNECT_TIMEOUT_START),
320 0 : m_target(target)
321 : {
322 0 : reconnect_ev = event_new(base, -1, 0, reconnect_cb, this);
323 0 : if (!reconnect_ev)
324 0 : LogPrintf("tor: Failed to create event for reconnection: out of memory?\n");
325 : // Start connection attempts immediately
326 0 : if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
327 0 : std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
328 0 : LogPrintf("tor: Initiating connection to Tor control port %s failed\n", m_tor_control_center);
329 0 : }
330 : // Read service private key if cached
331 0 : std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
332 0 : if (pkf.first) {
333 0 : LogPrint(BCLog::TOR, "Reading cached private key from %s\n", fs::PathToString(GetPrivateKeyFile()));
334 0 : private_key = pkf.second;
335 0 : }
336 0 : }
337 :
338 0 : TorController::~TorController()
339 : {
340 0 : if (reconnect_ev) {
341 0 : event_free(reconnect_ev);
342 0 : reconnect_ev = nullptr;
343 0 : }
344 0 : if (service.IsValid()) {
345 0 : RemoveLocal(service);
346 0 : }
347 0 : }
348 :
349 0 : void TorController::get_socks_cb(TorControlConnection& _conn, const TorControlReply& reply)
350 : {
351 : // NOTE: We can only get here if -onion is unset
352 0 : std::string socks_location;
353 0 : if (reply.code == 250) {
354 0 : for (const auto& line : reply.lines) {
355 0 : if (0 == line.compare(0, 20, "net/listeners/socks=")) {
356 0 : const std::string port_list_str = line.substr(20);
357 0 : std::vector<std::string> port_list = SplitString(port_list_str, ' ');
358 :
359 0 : for (auto& portstr : port_list) {
360 0 : if (portstr.empty()) continue;
361 0 : if ((portstr[0] == '"' || portstr[0] == '\'') && portstr.size() >= 2 && (*portstr.rbegin() == portstr[0])) {
362 0 : portstr = portstr.substr(1, portstr.size() - 2);
363 0 : if (portstr.empty()) continue;
364 0 : }
365 0 : socks_location = portstr;
366 0 : if (0 == portstr.compare(0, 10, "127.0.0.1:")) {
367 : // Prefer localhost - ignore other ports
368 0 : break;
369 : }
370 : }
371 0 : }
372 : }
373 0 : if (!socks_location.empty()) {
374 0 : LogPrint(BCLog::TOR, "Get SOCKS port command yielded %s\n", socks_location);
375 0 : } else {
376 0 : LogPrintf("tor: Get SOCKS port command returned nothing\n");
377 : }
378 0 : } else if (reply.code == 510) { // 510 Unrecognized command
379 0 : LogPrintf("tor: Get SOCKS port command failed with unrecognized command (You probably should upgrade Tor)\n");
380 0 : } else {
381 0 : LogPrintf("tor: Get SOCKS port command failed; error code %d\n", reply.code);
382 : }
383 :
384 0 : CService resolved;
385 0 : Assume(!resolved.IsValid());
386 0 : if (!socks_location.empty()) {
387 0 : resolved = LookupNumeric(socks_location, DEFAULT_TOR_SOCKS_PORT);
388 0 : }
389 0 : if (!resolved.IsValid()) {
390 : // Fallback to old behaviour
391 0 : resolved = LookupNumeric("127.0.0.1", DEFAULT_TOR_SOCKS_PORT);
392 0 : }
393 :
394 0 : Assume(resolved.IsValid());
395 0 : LogPrint(BCLog::TOR, "Configuring onion proxy for %s\n", resolved.ToStringAddrPort());
396 0 : Proxy addrOnion = Proxy(resolved, true);
397 0 : SetProxy(NET_ONION, addrOnion);
398 :
399 0 : const auto onlynets = gArgs.GetArgs("-onlynet");
400 :
401 0 : const bool onion_allowed_by_onlynet{
402 0 : !gArgs.IsArgSet("-onlynet") ||
403 0 : std::any_of(onlynets.begin(), onlynets.end(), [](const auto& n) {
404 0 : return ParseNetwork(n) == NET_ONION;
405 : })};
406 :
407 0 : 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.
412 0 : SetReachable(NET_ONION, true);
413 0 : }
414 0 : }
415 :
416 0 : void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlReply& reply)
417 : {
418 0 : if (reply.code == 250) {
419 0 : LogPrint(BCLog::TOR, "ADD_ONION successful\n");
420 0 : for (const std::string &s : reply.lines) {
421 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(s);
422 0 : std::map<std::string,std::string>::iterator i;
423 0 : if ((i = m.find("ServiceID")) != m.end())
424 0 : service_id = i->second;
425 0 : if ((i = m.find("PrivateKey")) != m.end())
426 0 : private_key = i->second;
427 0 : }
428 0 : if (service_id.empty()) {
429 0 : LogPrintf("tor: Error parsing ADD_ONION parameters:\n");
430 0 : for (const std::string &s : reply.lines) {
431 0 : LogPrintf(" %s\n", SanitizeString(s));
432 : }
433 0 : return;
434 : }
435 0 : service = LookupNumeric(std::string(service_id+".onion"), Params().GetDefaultPort());
436 0 : LogPrintfCategory(BCLog::TOR, "Got service ID %s, advertising service %s\n", service_id, service.ToStringAddrPort());
437 0 : if (WriteBinaryFile(GetPrivateKeyFile(), private_key)) {
438 0 : LogPrint(BCLog::TOR, "Cached service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
439 0 : } else {
440 0 : LogPrintf("tor: Error writing service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
441 : }
442 0 : AddLocal(service, LOCAL_MANUAL);
443 : // ... onion requested - keep connection open
444 0 : } else if (reply.code == 510) { // 510 Unrecognized command
445 0 : LogPrintf("tor: Add onion failed with unrecognized command (You probably need to upgrade Tor)\n");
446 0 : } else {
447 0 : LogPrintf("tor: Add onion failed; error code %d\n", reply.code);
448 : }
449 0 : }
450 :
451 0 : void TorController::auth_cb(TorControlConnection& _conn, const TorControlReply& reply)
452 : {
453 0 : if (reply.code == 250) {
454 0 : 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 0 : if (gArgs.GetArg("-onion", "") == "") {
459 0 : _conn.Command("GETINFO net/listeners/socks", std::bind(&TorController::get_socks_cb, this, std::placeholders::_1, std::placeholders::_2));
460 0 : }
461 :
462 : // Finally - now create the service
463 0 : if (private_key.empty()) { // No private key, generate one
464 0 : private_key = "NEW:ED25519-V3"; // Explicitly request key type - see issue #9214
465 0 : }
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 0 : _conn.Command(strprintf("ADD_ONION %s Port=%i,%s", private_key, Params().GetDefaultPort(), m_target.ToStringAddrPort()),
469 0 : std::bind(&TorController::add_onion_cb, this, std::placeholders::_1, std::placeholders::_2));
470 0 : } else {
471 0 : LogPrintf("tor: Authentication failed\n");
472 : }
473 0 : }
474 :
475 : /** Compute Tor SAFECOOKIE response.
476 : *
477 : * ServerHash is computed as:
478 : * HMAC-SHA256("Tor safe cookie authentication server-to-controller hash",
479 : * CookieString | ClientNonce | ServerNonce)
480 : * (with the HMAC key as its first argument)
481 : *
482 : * After a controller sends a successful AUTHCHALLENGE command, the
483 : * next command sent on the connection must be an AUTHENTICATE command,
484 : * and the only authentication string which that AUTHENTICATE command
485 : * will accept is:
486 : *
487 : * HMAC-SHA256("Tor safe cookie authentication controller-to-server hash",
488 : * CookieString | ClientNonce | ServerNonce)
489 : *
490 : */
491 0 : 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 0 : CHMAC_SHA256 computeHash((const uint8_t*)key.data(), key.size());
494 0 : std::vector<uint8_t> computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0);
495 0 : computeHash.Write(cookie.data(), cookie.size());
496 0 : computeHash.Write(clientNonce.data(), clientNonce.size());
497 0 : computeHash.Write(serverNonce.data(), serverNonce.size());
498 0 : computeHash.Finalize(computedHash.data());
499 0 : return computedHash;
500 0 : }
501 :
502 0 : void TorController::authchallenge_cb(TorControlConnection& _conn, const TorControlReply& reply)
503 : {
504 0 : if (reply.code == 250) {
505 0 : LogPrint(BCLog::TOR, "SAFECOOKIE authentication challenge successful\n");
506 0 : std::pair<std::string,std::string> l = SplitTorReplyLine(reply.lines[0]);
507 0 : if (l.first == "AUTHCHALLENGE") {
508 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
509 0 : if (m.empty()) {
510 0 : LogPrintf("tor: Error parsing AUTHCHALLENGE parameters: %s\n", SanitizeString(l.second));
511 0 : return;
512 : }
513 0 : std::vector<uint8_t> serverHash = ParseHex(m["SERVERHASH"]);
514 0 : std::vector<uint8_t> serverNonce = ParseHex(m["SERVERNONCE"]);
515 0 : LogPrint(BCLog::TOR, "AUTHCHALLENGE ServerHash %s ServerNonce %s\n", HexStr(serverHash), HexStr(serverNonce));
516 0 : if (serverNonce.size() != 32) {
517 0 : LogPrintf("tor: ServerNonce is not 32 bytes, as required by spec\n");
518 0 : return;
519 : }
520 :
521 0 : std::vector<uint8_t> computedServerHash = ComputeResponse(TOR_SAFE_SERVERKEY, cookie, clientNonce, serverNonce);
522 0 : if (computedServerHash != serverHash) {
523 0 : LogPrintf("tor: ServerHash %s does not match expected ServerHash %s\n", HexStr(serverHash), HexStr(computedServerHash));
524 0 : return;
525 : }
526 :
527 0 : std::vector<uint8_t> computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, cookie, clientNonce, serverNonce);
528 0 : _conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
529 0 : } else {
530 0 : LogPrintf("tor: Invalid reply to AUTHCHALLENGE\n");
531 : }
532 0 : } else {
533 0 : LogPrintf("tor: SAFECOOKIE authentication challenge failed\n");
534 : }
535 0 : }
536 :
537 0 : void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorControlReply& reply)
538 : {
539 0 : if (reply.code == 250) {
540 0 : std::set<std::string> methods;
541 0 : 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 0 : for (const std::string &s : reply.lines) {
548 0 : std::pair<std::string,std::string> l = SplitTorReplyLine(s);
549 0 : if (l.first == "AUTH") {
550 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
551 0 : std::map<std::string,std::string>::iterator i;
552 0 : if ((i = m.find("METHODS")) != m.end()) {
553 0 : std::vector<std::string> m_vec = SplitString(i->second, ',');
554 0 : methods = std::set<std::string>(m_vec.begin(), m_vec.end());
555 0 : }
556 0 : if ((i = m.find("COOKIEFILE")) != m.end())
557 0 : cookiefile = i->second;
558 0 : } else if (l.first == "VERSION") {
559 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
560 0 : std::map<std::string,std::string>::iterator i;
561 0 : if ((i = m.find("Tor")) != m.end()) {
562 0 : LogPrint(BCLog::TOR, "Connected to Tor version %s\n", i->second);
563 0 : }
564 0 : }
565 0 : }
566 0 : for (const std::string &s : methods) {
567 0 : 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 0 : std::string torpassword = gArgs.GetArg("-torpassword", "");
575 0 : if (!torpassword.empty()) {
576 0 : if (methods.count("HASHEDPASSWORD")) {
577 0 : LogPrint(BCLog::TOR, "Using HASHEDPASSWORD authentication\n");
578 0 : ReplaceAll(torpassword, "\"", "\\\"");
579 0 : _conn.Command("AUTHENTICATE \"" + torpassword + "\"", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
580 0 : } else {
581 0 : LogPrintf("tor: Password provided with -torpassword, but HASHEDPASSWORD authentication is not available\n");
582 : }
583 0 : } else if (methods.count("NULL")) {
584 0 : LogPrint(BCLog::TOR, "Using NULL authentication\n");
585 0 : _conn.Command("AUTHENTICATE", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
586 0 : } else if (methods.count("SAFECOOKIE")) {
587 : // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie
588 0 : LogPrint(BCLog::TOR, "Using SAFECOOKIE authentication, reading cookie authentication from %s\n", cookiefile);
589 0 : std::pair<bool,std::string> status_cookie = ReadBinaryFile(fs::PathFromString(cookiefile), TOR_COOKIE_SIZE);
590 0 : 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 0 : cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
593 0 : clientNonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
594 0 : GetRandBytes(clientNonce);
595 0 : _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce), std::bind(&TorController::authchallenge_cb, this, std::placeholders::_1, std::placeholders::_2));
596 0 : } else {
597 0 : if (status_cookie.first) {
598 0 : LogPrintf("tor: Authentication cookie %s is not exactly %i bytes, as is required by the spec\n", cookiefile, TOR_COOKIE_SIZE);
599 0 : } else {
600 0 : LogPrintf("tor: Authentication cookie %s could not be opened (check permissions)\n", cookiefile);
601 : }
602 : }
603 0 : } else if (methods.count("HASHEDPASSWORD")) {
604 0 : LogPrintf("tor: The only supported authentication mechanism left is password, but no password provided with -torpassword\n");
605 0 : } else {
606 0 : LogPrintf("tor: No supported authentication method\n");
607 : }
608 0 : } else {
609 0 : LogPrintf("tor: Requesting protocol info failed\n");
610 : }
611 0 : }
612 :
613 0 : void TorController::connected_cb(TorControlConnection& _conn)
614 : {
615 0 : reconnect_timeout = RECONNECT_TIMEOUT_START;
616 : // First send a PROTOCOLINFO command to figure out what authentication is expected
617 0 : if (!_conn.Command("PROTOCOLINFO 1", std::bind(&TorController::protocolinfo_cb, this, std::placeholders::_1, std::placeholders::_2)))
618 0 : LogPrintf("tor: Error sending initial protocolinfo command\n");
619 0 : }
620 :
621 0 : void TorController::disconnected_cb(TorControlConnection& _conn)
622 : {
623 : // Stop advertising service when disconnected
624 0 : if (service.IsValid())
625 0 : RemoveLocal(service);
626 0 : service = CService();
627 0 : if (!reconnect)
628 0 : return;
629 :
630 0 : 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 0 : struct timeval time = MillisToTimeval(int64_t(reconnect_timeout * 1000.0));
634 0 : if (reconnect_ev)
635 0 : event_add(reconnect_ev, &time);
636 0 : reconnect_timeout *= RECONNECT_TIMEOUT_EXP;
637 0 : }
638 :
639 0 : void TorController::Reconnect()
640 : {
641 : /* Try to reconnect and reestablish if we get booted - for example, Tor
642 : * may be restarting.
643 : */
644 0 : if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
645 0 : std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
646 0 : LogPrintf("tor: Re-initiating connection to Tor control port %s failed\n", m_tor_control_center);
647 0 : }
648 0 : }
649 :
650 0 : fs::path TorController::GetPrivateKeyFile()
651 : {
652 0 : return gArgs.GetDataDirNet() / "onion_v3_private_key";
653 0 : }
654 :
655 0 : void TorController::reconnect_cb(evutil_socket_t fd, short what, void *arg)
656 : {
657 0 : TorController *self = static_cast<TorController*>(arg);
658 0 : self->Reconnect();
659 0 : }
660 :
661 : /****** Thread ********/
662 : static struct event_base *gBase;
663 2 : static std::thread torControlThread;
664 :
665 0 : static void TorControlThread(CService onion_service_target)
666 : {
667 0 : TorController ctrl(gBase, gArgs.GetArg("-torcontrol", DEFAULT_TOR_CONTROL), onion_service_target);
668 :
669 0 : event_base_dispatch(gBase);
670 0 : }
671 :
672 0 : void StartTorControl(CService onion_service_target)
673 : {
674 0 : assert(!gBase);
675 : #ifdef WIN32
676 : evthread_use_windows_threads();
677 : #else
678 0 : evthread_use_pthreads();
679 : #endif
680 0 : gBase = event_base_new();
681 0 : if (!gBase) {
682 0 : LogPrintf("tor: Unable to create event_base\n");
683 0 : return;
684 : }
685 :
686 0 : torControlThread = std::thread(&util::TraceThread, "torcontrol", [onion_service_target] {
687 0 : TorControlThread(onion_service_target);
688 0 : });
689 0 : }
690 :
691 0 : void InterruptTorControl()
692 : {
693 0 : if (gBase) {
694 0 : LogPrintf("tor: Thread interrupt\n");
695 0 : event_base_once(gBase, -1, EV_TIMEOUT, [](evutil_socket_t, short, void*) {
696 0 : event_base_loopbreak(gBase);
697 0 : }, nullptr, nullptr);
698 0 : }
699 0 : }
700 :
701 0 : void StopTorControl()
702 : {
703 0 : if (gBase) {
704 0 : torControlThread.join();
705 0 : event_base_free(gBase);
706 0 : gBase = nullptr;
707 0 : }
708 0 : }
709 :
710 0 : CService DefaultOnionServiceTarget()
711 : {
712 : struct in_addr onion_service_target;
713 0 : onion_service_target.s_addr = htonl(INADDR_LOOPBACK);
714 0 : return {onion_service_target, BaseParams().OnionServiceTargetPort()};
715 : }
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