Branch data 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 : : #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 <cstdint>
30 : : #include <cstdlib>
31 : : #include <deque>
32 : : #include <functional>
33 : : #include <map>
34 : : #include <optional>
35 : : #include <set>
36 : : #include <thread>
37 : : #include <utility>
38 : : #include <vector>
39 : :
40 : : #include <event2/buffer.h>
41 : : #include <event2/bufferevent.h>
42 : : #include <event2/event.h>
43 : : #include <event2/thread.h>
44 : : #include <event2/util.h>
45 : :
46 : : using util::ReplaceAll;
47 : : using util::SplitString;
48 : : using util::ToString;
49 : :
50 : : /** Default control ip and port */
51 : : const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT);
52 : : /** Tor cookie size (from control-spec.txt) */
53 : : static const int TOR_COOKIE_SIZE = 32;
54 : : /** Size of client/server nonce for SAFECOOKIE */
55 : : static const int TOR_NONCE_SIZE = 32;
56 : : /** For computing serverHash in SAFECOOKIE */
57 : : static const std::string TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash";
58 : : /** For computing clientHash in SAFECOOKIE */
59 : : static const std::string TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash";
60 : : /** Exponential backoff configuration - initial timeout in seconds */
61 : : static const float RECONNECT_TIMEOUT_START = 1.0;
62 : : /** Exponential backoff configuration - growth factor */
63 : : static const float RECONNECT_TIMEOUT_EXP = 1.5;
64 : : /** Maximum reconnect timeout in seconds to prevent excessive delays */
65 : : static const float RECONNECT_TIMEOUT_MAX = 600.0;
66 : : /** Maximum length for lines received on TorControlConnection.
67 : : * tor-control-spec.txt mentions that there is explicitly no limit defined to line length,
68 : : * this is belt-and-suspenders sanity limit to prevent memory exhaustion.
69 : : */
70 : : static const int MAX_LINE_LENGTH = 100000;
71 : : static const uint16_t DEFAULT_TOR_SOCKS_PORT = 9050;
72 : :
73 : : /****** Low-level TorControlConnection ********/
74 : :
75 : 1 : TorControlConnection::TorControlConnection(struct event_base* _base)
76 [ + - ]: 1 : : base(_base)
77 : : {
78 : 1 : }
79 : :
80 : 1 : TorControlConnection::~TorControlConnection()
81 : : {
82 [ - + ]: 1 : if (b_conn)
83 : 0 : bufferevent_free(b_conn);
84 : 1 : }
85 : :
86 : 0 : void TorControlConnection::readcb(struct bufferevent *bev, void *ctx)
87 : : {
88 : 0 : TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
89 : 0 : struct evbuffer *input = bufferevent_get_input(bev);
90 : 0 : size_t n_read_out = 0;
91 : 0 : char *line;
92 [ # # ]: 0 : assert(input);
93 : : // If there is not a whole line to read, evbuffer_readln returns nullptr
94 [ # # ]: 0 : while((line = evbuffer_readln(input, &n_read_out, EVBUFFER_EOL_CRLF)) != nullptr)
95 : : {
96 : 0 : std::string s(line, n_read_out);
97 : 0 : free(line);
98 [ # # ]: 0 : if (s.size() < 4) // Short line
99 : 0 : continue;
100 : : // <status>(-|+| )<data><CRLF>
101 [ # # # # ]: 0 : self->message.code = ToIntegral<int>(s.substr(0, 3)).value_or(0);
102 [ # # ]: 0 : self->message.lines.push_back(s.substr(4));
103 [ # # ]: 0 : char ch = s[3]; // '-','+' or ' '
104 [ # # ]: 0 : if (ch == ' ') {
105 : : // Final line, dispatch reply and clean up
106 [ # # ]: 0 : if (self->message.code >= 600) {
107 : : // (currently unused)
108 : : // Dispatch async notifications to async handler
109 : : // Synchronous and asynchronous messages are never interleaved
110 : : } else {
111 [ # # ]: 0 : if (!self->reply_handlers.empty()) {
112 : : // Invoke reply handler with message
113 [ # # ]: 0 : self->reply_handlers.front()(*self, self->message);
114 : 0 : self->reply_handlers.pop_front();
115 : : } else {
116 [ # # # # : 0 : LogDebug(BCLog::TOR, "Received unexpected sync reply %i\n", self->message.code);
# # ]
117 : : }
118 : : }
119 : 0 : self->message.Clear();
120 : : }
121 : 0 : }
122 : : // Check for size of buffer - protect against memory exhaustion with very long lines
123 : : // Do this after evbuffer_readln to make sure all full lines have been
124 : : // removed from the buffer. Everything left is an incomplete line.
125 [ # # ]: 0 : if (evbuffer_get_length(input) > MAX_LINE_LENGTH) {
126 : 0 : LogPrintf("tor: Disconnecting because MAX_LINE_LENGTH exceeded\n");
127 : 0 : self->Disconnect();
128 : : }
129 : 0 : }
130 : :
131 : 1 : void TorControlConnection::eventcb(struct bufferevent *bev, short what, void *ctx)
132 : : {
133 : 1 : TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
134 [ - + ]: 1 : if (what & BEV_EVENT_CONNECTED) {
135 [ # # ]: 0 : LogDebug(BCLog::TOR, "Successfully connected!\n");
136 : 0 : self->connected(*self);
137 [ + - ]: 1 : } else if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
138 [ + - ]: 1 : if (what & BEV_EVENT_ERROR) {
139 [ + - ]: 1 : LogDebug(BCLog::TOR, "Error connecting to Tor control socket\n");
140 : : } else {
141 [ # # ]: 0 : LogDebug(BCLog::TOR, "End of stream\n");
142 : : }
143 : 1 : self->Disconnect();
144 : 1 : self->disconnected(*self);
145 : : }
146 : 1 : }
147 : :
148 : 1 : bool TorControlConnection::Connect(const std::string& tor_control_center, const ConnectionCB& _connected, const ConnectionCB& _disconnected)
149 : : {
150 [ - + ]: 1 : if (b_conn) {
151 : 0 : Disconnect();
152 : : }
153 : :
154 [ + - ]: 1 : const std::optional<CService> control_service{Lookup(tor_control_center, DEFAULT_TOR_CONTROL_PORT, fNameLookup)};
155 [ - + ]: 1 : if (!control_service.has_value()) {
156 [ # # ]: 0 : LogPrintf("tor: Failed to look up control center %s\n", tor_control_center);
157 : : return false;
158 : : }
159 : :
160 : 1 : struct sockaddr_storage control_address;
161 : 1 : socklen_t control_address_len = sizeof(control_address);
162 [ + - - + ]: 1 : if (!control_service.value().GetSockAddr(reinterpret_cast<struct sockaddr*>(&control_address), &control_address_len)) {
163 [ # # ]: 0 : LogPrintf("tor: Error parsing socket address %s\n", tor_control_center);
164 : : return false;
165 : : }
166 : :
167 : : // Create a new socket, set up callbacks and enable notification bits
168 [ + - ]: 1 : b_conn = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE);
169 [ + - ]: 1 : if (!b_conn) {
170 : : return false;
171 : : }
172 [ + - ]: 1 : bufferevent_setcb(b_conn, TorControlConnection::readcb, nullptr, TorControlConnection::eventcb, this);
173 [ + - ]: 1 : bufferevent_enable(b_conn, EV_READ|EV_WRITE);
174 [ + - ]: 1 : this->connected = _connected;
175 [ + - ]: 1 : this->disconnected = _disconnected;
176 : :
177 : : // Finally, connect to tor_control_center
178 [ + - - + ]: 1 : if (bufferevent_socket_connect(b_conn, reinterpret_cast<struct sockaddr*>(&control_address), control_address_len) < 0) {
179 [ # # ]: 0 : LogPrintf("tor: Error connecting to address %s\n", tor_control_center);
180 : : return false;
181 : : }
182 : : return true;
183 : 1 : }
184 : :
185 : 1 : void TorControlConnection::Disconnect()
186 : : {
187 [ + - ]: 1 : if (b_conn)
188 : 1 : bufferevent_free(b_conn);
189 : 1 : b_conn = nullptr;
190 : 1 : }
191 : :
192 : 0 : bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler)
193 : : {
194 [ # # ]: 0 : if (!b_conn)
195 : : return false;
196 : 0 : struct evbuffer *buf = bufferevent_get_output(b_conn);
197 [ # # ]: 0 : if (!buf)
198 : : return false;
199 : 0 : evbuffer_add(buf, cmd.data(), cmd.size());
200 : 0 : evbuffer_add(buf, "\r\n", 2);
201 : 0 : reply_handlers.push_back(reply_handler);
202 : 0 : return true;
203 : : }
204 : :
205 : : /****** General parsing utilities ********/
206 : :
207 : : /* Split reply line in the form 'AUTH METHODS=...' into a type
208 : : * 'AUTH' and arguments 'METHODS=...'.
209 : : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
210 : : * the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24).
211 : : */
212 : 10 : std::pair<std::string,std::string> SplitTorReplyLine(const std::string &s)
213 : : {
214 : 10 : size_t ptr=0;
215 : 10 : std::string type;
216 [ + + + + ]: 82 : while (ptr < s.size() && s[ptr] != ' ') {
217 [ + - ]: 72 : type.push_back(s[ptr]);
218 : 72 : ++ptr;
219 : : }
220 [ + + ]: 10 : if (ptr < s.size())
221 : 9 : ++ptr; // skip ' '
222 [ + - ]: 20 : return make_pair(type, s.substr(ptr));
223 : 10 : }
224 : :
225 : : /** Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'.
226 : : * Returns a map of keys to values, or an empty map if there was an error.
227 : : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
228 : : * the server reply formats for PROTOCOLINFO (S3.21), AUTHCHALLENGE (S3.24),
229 : : * and ADD_ONION (S3.27). See also sections 2.1 and 2.3.
230 : : */
231 : 27 : std::map<std::string,std::string> ParseTorReplyMapping(const std::string &s)
232 : : {
233 : 27 : std::map<std::string,std::string> mapping;
234 : 27 : size_t ptr=0;
235 [ + + ]: 58 : while (ptr < s.size()) {
236 : 38 : std::string key, value;
237 [ + + + + : 246 : while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
+ + ]
238 [ + - ]: 208 : key.push_back(s[ptr]);
239 : 208 : ++ptr;
240 : : }
241 [ + + ]: 38 : if (ptr == s.size()) // unexpected end of line
242 : 1 : return std::map<std::string,std::string>();
243 [ + + ]: 37 : if (s[ptr] == ' ') // The remaining string is an OptArguments
244 : : break;
245 : 32 : ++ptr; // skip '='
246 [ - + + + ]: 32 : if (ptr < s.size() && s[ptr] == '"') { // Quoted string
247 : 18 : ++ptr; // skip opening '"'
248 : 18 : bool escape_next = false;
249 [ + + + + : 224 : while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
+ + ]
250 : : // Repeated backslashes must be interpreted as pairs
251 [ + + + + ]: 206 : escape_next = (s[ptr] == '\\' && !escape_next);
252 [ + - ]: 206 : value.push_back(s[ptr]);
253 : 206 : ++ptr;
254 : : }
255 [ + + ]: 18 : if (ptr == s.size()) // unexpected end of line
256 : 1 : return std::map<std::string,std::string>();
257 : 17 : ++ptr; // skip closing '"'
258 : : /**
259 : : * Unescape value. Per https://spec.torproject.org/control-spec section 2.1.1:
260 : : *
261 : : * For future-proofing, controller implementers MAY use the following
262 : : * rules to be compatible with buggy Tor implementations and with
263 : : * future ones that implement the spec as intended:
264 : : *
265 : : * Read \n \t \r and \0 ... \377 as C escapes.
266 : : * Treat a backslash followed by any other character as that character.
267 : : */
268 : 17 : std::string escaped_value;
269 [ + + ]: 183 : for (size_t i = 0; i < value.size(); ++i) {
270 [ + + ]: 166 : if (value[i] == '\\') {
271 : : // This will always be valid, because if the QuotedString
272 : : // ended in an odd number of backslashes, then the parser
273 : : // would already have returned above, due to a missing
274 : : // terminating double-quote.
275 : 23 : ++i;
276 [ + + ]: 23 : if (value[i] == 'n') {
277 [ + - ]: 1 : escaped_value.push_back('\n');
278 [ + + ]: 22 : } else if (value[i] == 't') {
279 [ + - ]: 1 : escaped_value.push_back('\t');
280 [ + + ]: 21 : } else if (value[i] == 'r') {
281 [ + - ]: 1 : escaped_value.push_back('\r');
282 [ + + + + ]: 20 : } else if ('0' <= value[i] && value[i] <= '7') {
283 : : size_t j;
284 : : // Octal escape sequences have a limit of three octal digits,
285 : : // but terminate at the first character that is not a valid
286 : : // octal digit if encountered sooner.
287 [ + + + + : 21 : for (j = 1; j < 3 && (i+j) < value.size() && '0' <= value[i+j] && value[i+j] <= '7'; ++j) {}
+ - + + ]
288 : : // Tor restricts first digit to 0-3 for three-digit octals.
289 : : // A leading digit of 4-7 would therefore be interpreted as
290 : : // a two-digit octal.
291 [ + + + + ]: 11 : if (j == 3 && value[i] > '3') {
292 : 1 : j--;
293 : : }
294 : 11 : const auto end{i + j};
295 : 11 : uint8_t val{0};
296 [ + + ]: 31 : while (i < end) {
297 : 20 : val *= 8;
298 : 20 : val += value[i++] - '0';
299 : : }
300 [ + - ]: 11 : escaped_value.push_back(char(val));
301 : : // Account for automatic incrementing at loop end
302 : 11 : --i;
303 : : } else {
304 [ + - ]: 9 : escaped_value.push_back(value[i]);
305 : : }
306 : : } else {
307 [ + - ]: 143 : escaped_value.push_back(value[i]);
308 : : }
309 : : }
310 [ + - ]: 34 : value = escaped_value;
311 : 17 : } else { // Unquoted value. Note that values can contain '=' at will, just no spaces
312 [ + + + + ]: 132 : while (ptr < s.size() && s[ptr] != ' ') {
313 [ + - ]: 118 : value.push_back(s[ptr]);
314 : 118 : ++ptr;
315 : : }
316 : : }
317 [ + + + - ]: 31 : if (ptr < s.size() && s[ptr] == ' ')
318 : 11 : ++ptr; // skip ' ' after key=value
319 [ + - + - ]: 62 : mapping[key] = value;
320 : 38 : }
321 : 25 : return mapping;
322 : 27 : }
323 : :
324 : 1 : TorController::TorController(struct event_base* _base, const std::string& tor_control_center, const CService& target):
325 : 1 : base(_base),
326 [ + - + - ]: 1 : m_tor_control_center(tor_control_center), conn(base), reconnect(true), reconnect_timeout(RECONNECT_TIMEOUT_START),
327 [ + - + - ]: 1 : m_target(target)
328 : : {
329 [ + - ]: 1 : reconnect_ev = event_new(base, -1, 0, reconnect_cb, this);
330 [ - + ]: 1 : if (!reconnect_ev)
331 [ # # ]: 0 : LogPrintf("tor: Failed to create event for reconnection: out of memory?\n");
332 : : // Start connection attempts immediately
333 [ + - + - : 1 : if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
- + ]
334 [ + - ]: 1 : std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
335 [ # # ]: 0 : LogPrintf("tor: Initiating connection to Tor control port %s failed\n", m_tor_control_center);
336 : : }
337 : : // Read service private key if cached
338 [ + - + - ]: 1 : std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
339 [ - + ]: 1 : if (pkf.first) {
340 [ # # # # : 0 : LogDebug(BCLog::TOR, "Reading cached private key from %s\n", fs::PathToString(GetPrivateKeyFile()));
# # # # ]
341 [ - - ]: 1 : private_key = pkf.second;
342 : : }
343 : 1 : }
344 : :
345 : 1 : TorController::~TorController()
346 : : {
347 [ + - ]: 1 : if (reconnect_ev) {
348 : 1 : event_free(reconnect_ev);
349 : 1 : reconnect_ev = nullptr;
350 : : }
351 [ - + ]: 1 : if (service.IsValid()) {
352 : 0 : RemoveLocal(service);
353 : : }
354 : 1 : }
355 : :
356 : 0 : void TorController::get_socks_cb(TorControlConnection& _conn, const TorControlReply& reply)
357 : : {
358 : : // NOTE: We can only get here if -onion is unset
359 [ # # ]: 0 : std::string socks_location;
360 [ # # ]: 0 : if (reply.code == 250) {
361 [ # # ]: 0 : for (const auto& line : reply.lines) {
362 [ # # ]: 0 : if (line.starts_with("net/listeners/socks=")) {
363 [ # # ]: 0 : const std::string port_list_str = line.substr(20);
364 [ # # ]: 0 : std::vector<std::string> port_list = SplitString(port_list_str, ' ');
365 : :
366 [ # # ]: 0 : for (auto& portstr : port_list) {
367 [ # # ]: 0 : if (portstr.empty()) continue;
368 [ # # # # : 0 : if ((portstr[0] == '"' || portstr[0] == '\'') && portstr.size() >= 2 && (*portstr.rbegin() == portstr[0])) {
# # # # ]
369 [ # # ]: 0 : portstr = portstr.substr(1, portstr.size() - 2);
370 [ # # ]: 0 : if (portstr.empty()) continue;
371 : : }
372 [ # # ]: 0 : socks_location = portstr;
373 [ # # ]: 0 : if (portstr.starts_with("127.0.0.1:")) {
374 : : // Prefer localhost - ignore other ports
375 : : break;
376 : : }
377 : : }
378 : 0 : }
379 : : }
380 [ # # ]: 0 : if (!socks_location.empty()) {
381 [ # # # # : 0 : LogDebug(BCLog::TOR, "Get SOCKS port command yielded %s\n", socks_location);
# # ]
382 : : } else {
383 [ # # ]: 0 : LogPrintf("tor: Get SOCKS port command returned nothing\n");
384 : : }
385 [ # # ]: 0 : } else if (reply.code == 510) { // 510 Unrecognized command
386 [ # # ]: 0 : LogPrintf("tor: Get SOCKS port command failed with unrecognized command (You probably should upgrade Tor)\n");
387 : : } else {
388 [ # # ]: 0 : LogPrintf("tor: Get SOCKS port command failed; error code %d\n", reply.code);
389 : : }
390 : :
391 [ # # ]: 0 : CService resolved;
392 [ # # ]: 0 : Assume(!resolved.IsValid());
393 [ # # ]: 0 : if (!socks_location.empty()) {
394 [ # # # # ]: 0 : resolved = LookupNumeric(socks_location, DEFAULT_TOR_SOCKS_PORT);
395 : : }
396 [ # # # # ]: 0 : if (!resolved.IsValid()) {
397 : : // Fallback to old behaviour
398 [ # # # # : 0 : resolved = LookupNumeric("127.0.0.1", DEFAULT_TOR_SOCKS_PORT);
# # ]
399 : : }
400 : :
401 [ # # ]: 0 : Assume(resolved.IsValid());
402 [ # # # # : 0 : LogDebug(BCLog::TOR, "Configuring onion proxy for %s\n", resolved.ToStringAddrPort());
# # # # ]
403 : 0 : Proxy addrOnion = Proxy(resolved, true);
404 [ # # ]: 0 : SetProxy(NET_ONION, addrOnion);
405 : :
406 [ # # # # ]: 0 : const auto onlynets = gArgs.GetArgs("-onlynet");
407 : :
408 : 0 : const bool onion_allowed_by_onlynet{
409 [ # # # # ]: 0 : onlynets.empty() ||
410 [ # # ]: 0 : std::any_of(onlynets.begin(), onlynets.end(), [](const auto& n) {
411 : 0 : return ParseNetwork(n) == NET_ONION;
412 : 0 : })};
413 : :
414 : 0 : if (onion_allowed_by_onlynet) {
415 : : // If NET_ONION is reachable, then the below is a noop.
416 : : //
417 : : // If NET_ONION is not reachable, then none of -proxy or -onion was given.
418 : : // Since we are here, then -torcontrol and -torpassword were given.
419 [ # # ]: 0 : g_reachable_nets.Add(NET_ONION);
420 : : }
421 : 0 : }
422 : :
423 : 0 : void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlReply& reply)
424 : : {
425 [ # # ]: 0 : if (reply.code == 250) {
426 [ # # ]: 0 : LogDebug(BCLog::TOR, "ADD_ONION successful\n");
427 [ # # ]: 0 : for (const std::string &s : reply.lines) {
428 : 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(s);
429 [ # # ]: 0 : std::map<std::string,std::string>::iterator i;
430 [ # # # # ]: 0 : if ((i = m.find("ServiceID")) != m.end())
431 [ # # ]: 0 : service_id = i->second;
432 [ # # # # ]: 0 : if ((i = m.find("PrivateKey")) != m.end())
433 [ # # ]: 0 : private_key = i->second;
434 : 0 : }
435 [ # # ]: 0 : if (service_id.empty()) {
436 : 0 : LogPrintf("tor: Error parsing ADD_ONION parameters:\n");
437 [ # # ]: 0 : for (const std::string &s : reply.lines) {
438 [ # # ]: 0 : LogPrintf(" %s\n", SanitizeString(s));
439 : : }
440 : : return;
441 : : }
442 [ # # # # : 0 : service = LookupNumeric(std::string(service_id+".onion"), Params().GetDefaultPort());
# # ]
443 [ # # ]: 0 : LogInfo("Got tor service ID %s, advertising service %s\n", service_id, service.ToStringAddrPort());
444 [ # # # # ]: 0 : if (WriteBinaryFile(GetPrivateKeyFile(), private_key)) {
445 [ # # # # : 0 : LogDebug(BCLog::TOR, "Cached service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
# # ]
446 : : } else {
447 [ # # # # ]: 0 : LogPrintf("tor: Error writing service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
448 : : }
449 : 0 : AddLocal(service, LOCAL_MANUAL);
450 : : // ... onion requested - keep connection open
451 [ # # ]: 0 : } else if (reply.code == 510) { // 510 Unrecognized command
452 : 0 : LogPrintf("tor: Add onion failed with unrecognized command (You probably need to upgrade Tor)\n");
453 : : } else {
454 : 0 : LogPrintf("tor: Add onion failed; error code %d\n", reply.code);
455 : : }
456 : : }
457 : :
458 : 0 : void TorController::auth_cb(TorControlConnection& _conn, const TorControlReply& reply)
459 : : {
460 [ # # ]: 0 : if (reply.code == 250) {
461 [ # # ]: 0 : LogDebug(BCLog::TOR, "Authentication successful\n");
462 : :
463 : : // Now that we know Tor is running setup the proxy for onion addresses
464 : : // if -onion isn't set to something else.
465 [ # # # # : 0 : if (gArgs.GetArg("-onion", "") == "") {
# # ]
466 [ # # # # ]: 0 : _conn.Command("GETINFO net/listeners/socks", std::bind(&TorController::get_socks_cb, this, std::placeholders::_1, std::placeholders::_2));
467 : : }
468 : :
469 : : // Finally - now create the service
470 [ # # ]: 0 : if (private_key.empty()) { // No private key, generate one
471 : 0 : private_key = "NEW:ED25519-V3"; // Explicitly request key type - see issue #9214
472 : : }
473 : : // Request onion service, redirect port.
474 : : // Note that the 'virtual' port is always the default port to avoid decloaking nodes using other ports.
475 [ # # # # : 0 : _conn.Command(strprintf("ADD_ONION %s Port=%i,%s", private_key, Params().GetDefaultPort(), m_target.ToStringAddrPort()),
# # # # ]
476 : 0 : std::bind(&TorController::add_onion_cb, this, std::placeholders::_1, std::placeholders::_2));
477 : : } else {
478 : 0 : LogPrintf("tor: Authentication failed\n");
479 : : }
480 : 0 : }
481 : :
482 : : /** Compute Tor SAFECOOKIE response.
483 : : *
484 : : * ServerHash is computed as:
485 : : * HMAC-SHA256("Tor safe cookie authentication server-to-controller hash",
486 : : * CookieString | ClientNonce | ServerNonce)
487 : : * (with the HMAC key as its first argument)
488 : : *
489 : : * After a controller sends a successful AUTHCHALLENGE command, the
490 : : * next command sent on the connection must be an AUTHENTICATE command,
491 : : * and the only authentication string which that AUTHENTICATE command
492 : : * will accept is:
493 : : *
494 : : * HMAC-SHA256("Tor safe cookie authentication controller-to-server hash",
495 : : * CookieString | ClientNonce | ServerNonce)
496 : : *
497 : : */
498 : 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)
499 : : {
500 : 0 : CHMAC_SHA256 computeHash((const uint8_t*)key.data(), key.size());
501 : 0 : std::vector<uint8_t> computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0);
502 [ # # ]: 0 : computeHash.Write(cookie.data(), cookie.size());
503 [ # # ]: 0 : computeHash.Write(clientNonce.data(), clientNonce.size());
504 [ # # ]: 0 : computeHash.Write(serverNonce.data(), serverNonce.size());
505 [ # # ]: 0 : computeHash.Finalize(computedHash.data());
506 : 0 : return computedHash;
507 : 0 : }
508 : :
509 : 0 : void TorController::authchallenge_cb(TorControlConnection& _conn, const TorControlReply& reply)
510 : : {
511 [ # # ]: 0 : if (reply.code == 250) {
512 [ # # ]: 0 : LogDebug(BCLog::TOR, "SAFECOOKIE authentication challenge successful\n");
513 : 0 : std::pair<std::string,std::string> l = SplitTorReplyLine(reply.lines[0]);
514 [ # # ]: 0 : if (l.first == "AUTHCHALLENGE") {
515 [ # # ]: 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
516 [ # # ]: 0 : if (m.empty()) {
517 [ # # # # ]: 0 : LogPrintf("tor: Error parsing AUTHCHALLENGE parameters: %s\n", SanitizeString(l.second));
518 : 0 : return;
519 : : }
520 [ # # # # : 0 : std::vector<uint8_t> serverHash = ParseHex(m["SERVERHASH"]);
# # ]
521 [ # # # # : 0 : std::vector<uint8_t> serverNonce = ParseHex(m["SERVERNONCE"]);
# # ]
522 [ # # # # : 0 : LogDebug(BCLog::TOR, "AUTHCHALLENGE ServerHash %s ServerNonce %s\n", HexStr(serverHash), HexStr(serverNonce));
# # # # #
# ]
523 [ # # ]: 0 : if (serverNonce.size() != 32) {
524 [ # # ]: 0 : LogPrintf("tor: ServerNonce is not 32 bytes, as required by spec\n");
525 : : return;
526 : : }
527 : :
528 [ # # ]: 0 : std::vector<uint8_t> computedServerHash = ComputeResponse(TOR_SAFE_SERVERKEY, cookie, clientNonce, serverNonce);
529 [ # # ]: 0 : if (computedServerHash != serverHash) {
530 [ # # # # : 0 : LogPrintf("tor: ServerHash %s does not match expected ServerHash %s\n", HexStr(serverHash), HexStr(computedServerHash));
# # ]
531 : 0 : return;
532 : : }
533 : :
534 [ # # ]: 0 : std::vector<uint8_t> computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, cookie, clientNonce, serverNonce);
535 [ # # # # : 0 : _conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
# # # # ]
536 : 0 : } else {
537 [ # # ]: 0 : LogPrintf("tor: Invalid reply to AUTHCHALLENGE\n");
538 : : }
539 : 0 : } else {
540 : 0 : LogPrintf("tor: SAFECOOKIE authentication challenge failed\n");
541 : : }
542 : : }
543 : :
544 : 0 : void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorControlReply& reply)
545 : : {
546 [ # # ]: 0 : if (reply.code == 250) {
547 : 0 : std::set<std::string> methods;
548 : 0 : std::string cookiefile;
549 : : /*
550 : : * 250-AUTH METHODS=COOKIE,SAFECOOKIE COOKIEFILE="/home/x/.tor/control_auth_cookie"
551 : : * 250-AUTH METHODS=NULL
552 : : * 250-AUTH METHODS=HASHEDPASSWORD
553 : : */
554 [ # # ]: 0 : for (const std::string &s : reply.lines) {
555 [ # # ]: 0 : std::pair<std::string,std::string> l = SplitTorReplyLine(s);
556 [ # # ]: 0 : if (l.first == "AUTH") {
557 [ # # ]: 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
558 [ # # ]: 0 : std::map<std::string,std::string>::iterator i;
559 [ # # # # ]: 0 : if ((i = m.find("METHODS")) != m.end()) {
560 [ # # ]: 0 : std::vector<std::string> m_vec = SplitString(i->second, ',');
561 [ # # ]: 0 : methods = std::set<std::string>(m_vec.begin(), m_vec.end());
562 : 0 : }
563 [ # # # # ]: 0 : if ((i = m.find("COOKIEFILE")) != m.end())
564 [ # # ]: 0 : cookiefile = i->second;
565 [ # # ]: 0 : } else if (l.first == "VERSION") {
566 [ # # ]: 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
567 [ # # ]: 0 : std::map<std::string,std::string>::iterator i;
568 [ # # # # ]: 0 : if ((i = m.find("Tor")) != m.end()) {
569 [ # # # # : 0 : LogDebug(BCLog::TOR, "Connected to Tor version %s\n", i->second);
# # ]
570 : : }
571 : 0 : }
572 : 0 : }
573 [ # # ]: 0 : for (const std::string &s : methods) {
574 [ # # # # : 0 : LogDebug(BCLog::TOR, "Supported authentication method: %s\n", s);
# # ]
575 : : }
576 : : // Prefer NULL, otherwise SAFECOOKIE. If a password is provided, use HASHEDPASSWORD
577 : : /* Authentication:
578 : : * cookie: hex-encoded ~/.tor/control_auth_cookie
579 : : * password: "password"
580 : : */
581 [ # # # # : 0 : std::string torpassword = gArgs.GetArg("-torpassword", "");
# # ]
582 [ # # ]: 0 : if (!torpassword.empty()) {
583 [ # # # # ]: 0 : if (methods.count("HASHEDPASSWORD")) {
584 [ # # # # : 0 : LogDebug(BCLog::TOR, "Using HASHEDPASSWORD authentication\n");
# # ]
585 [ # # # # : 0 : ReplaceAll(torpassword, "\"", "\\\"");
# # ]
586 [ # # # # : 0 : _conn.Command("AUTHENTICATE \"" + torpassword + "\"", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
# # ]
587 : : } else {
588 [ # # ]: 0 : LogPrintf("tor: Password provided with -torpassword, but HASHEDPASSWORD authentication is not available\n");
589 : : }
590 [ # # # # ]: 0 : } else if (methods.count("NULL")) {
591 [ # # # # : 0 : LogDebug(BCLog::TOR, "Using NULL authentication\n");
# # ]
592 [ # # # # : 0 : _conn.Command("AUTHENTICATE", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
# # ]
593 [ # # # # ]: 0 : } else if (methods.count("SAFECOOKIE")) {
594 : : // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie
595 [ # # # # : 0 : LogDebug(BCLog::TOR, "Using SAFECOOKIE authentication, reading cookie authentication from %s\n", cookiefile);
# # ]
596 [ # # # # ]: 0 : std::pair<bool,std::string> status_cookie = ReadBinaryFile(fs::PathFromString(cookiefile), TOR_COOKIE_SIZE);
597 [ # # # # ]: 0 : if (status_cookie.first && status_cookie.second.size() == TOR_COOKIE_SIZE) {
598 : : // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
599 [ # # # # ]: 0 : cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
600 [ # # ]: 0 : clientNonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
601 : 0 : GetRandBytes(clientNonce);
602 [ # # # # : 0 : _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce), std::bind(&TorController::authchallenge_cb, this, std::placeholders::_1, std::placeholders::_2));
# # # # ]
603 : : } else {
604 [ # # ]: 0 : if (status_cookie.first) {
605 [ # # ]: 0 : LogPrintf("tor: Authentication cookie %s is not exactly %i bytes, as is required by the spec\n", cookiefile, TOR_COOKIE_SIZE);
606 : : } else {
607 [ # # ]: 0 : LogPrintf("tor: Authentication cookie %s could not be opened (check permissions)\n", cookiefile);
608 : : }
609 : : }
610 [ # # # # ]: 0 : } else if (methods.count("HASHEDPASSWORD")) {
611 [ # # ]: 0 : LogPrintf("tor: The only supported authentication mechanism left is password, but no password provided with -torpassword\n");
612 : : } else {
613 [ # # ]: 0 : LogPrintf("tor: No supported authentication method\n");
614 : : }
615 : 0 : } else {
616 : 0 : LogPrintf("tor: Requesting protocol info failed\n");
617 : : }
618 : 0 : }
619 : :
620 : 0 : void TorController::connected_cb(TorControlConnection& _conn)
621 : : {
622 : 0 : reconnect_timeout = RECONNECT_TIMEOUT_START;
623 : : // First send a PROTOCOLINFO command to figure out what authentication is expected
624 [ # # # # : 0 : if (!_conn.Command("PROTOCOLINFO 1", std::bind(&TorController::protocolinfo_cb, this, std::placeholders::_1, std::placeholders::_2)))
# # ]
625 : 0 : LogPrintf("tor: Error sending initial protocolinfo command\n");
626 : 0 : }
627 : :
628 : 1 : void TorController::disconnected_cb(TorControlConnection& _conn)
629 : : {
630 : : // Stop advertising service when disconnected
631 [ - + ]: 1 : if (service.IsValid())
632 : 0 : RemoveLocal(service);
633 : 1 : service = CService();
634 [ + - ]: 1 : if (!reconnect)
635 : : return;
636 : :
637 [ + - ]: 1 : LogDebug(BCLog::TOR, "Not connected to Tor control port %s, retrying in %.2f s\n",
638 : : m_tor_control_center, reconnect_timeout);
639 : :
640 : : // Single-shot timer for reconnect. Use exponential backoff with a maximum.
641 : 1 : struct timeval time = MillisToTimeval(int64_t(reconnect_timeout * 1000.0));
642 [ + - ]: 1 : if (reconnect_ev)
643 : 1 : event_add(reconnect_ev, &time);
644 : :
645 [ + - ]: 2 : reconnect_timeout = std::min(reconnect_timeout * RECONNECT_TIMEOUT_EXP, RECONNECT_TIMEOUT_MAX);
646 : : }
647 : :
648 : 0 : void TorController::Reconnect()
649 : : {
650 : : /* Try to reconnect and reestablish if we get booted - for example, Tor
651 : : * may be restarting.
652 : : */
653 [ # # # # : 0 : if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
# # ]
654 : 0 : std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
655 : 0 : LogPrintf("tor: Re-initiating connection to Tor control port %s failed\n", m_tor_control_center);
656 : : }
657 : 0 : }
658 : :
659 : 1 : fs::path TorController::GetPrivateKeyFile()
660 : : {
661 [ + - ]: 3 : return gArgs.GetDataDirNet() / "onion_v3_private_key";
662 : : }
663 : :
664 : 0 : void TorController::reconnect_cb(evutil_socket_t fd, short what, void *arg)
665 : : {
666 : 0 : TorController *self = static_cast<TorController*>(arg);
667 : 0 : self->Reconnect();
668 : 0 : }
669 : :
670 : : /****** Thread ********/
671 : : static struct event_base *gBase;
672 : : static std::thread torControlThread;
673 : :
674 : 1 : static void TorControlThread(CService onion_service_target)
675 : : {
676 [ + - + - ]: 2 : TorController ctrl(gBase, gArgs.GetArg("-torcontrol", DEFAULT_TOR_CONTROL), onion_service_target);
677 : :
678 [ + - ]: 1 : event_base_dispatch(gBase);
679 : 1 : }
680 : :
681 : 1 : void StartTorControl(CService onion_service_target)
682 : : {
683 [ - + ]: 1 : assert(!gBase);
684 : : #ifdef WIN32
685 : : evthread_use_windows_threads();
686 : : #else
687 : 1 : evthread_use_pthreads();
688 : : #endif
689 : 1 : gBase = event_base_new();
690 [ - + ]: 1 : if (!gBase) {
691 : 0 : LogPrintf("tor: Unable to create event_base\n");
692 : 0 : return;
693 : : }
694 : :
695 [ + - ]: 4 : torControlThread = std::thread(&util::TraceThread, "torcontrol", [onion_service_target] {
696 [ + - ]: 1 : TorControlThread(onion_service_target);
697 [ + - ]: 2 : });
698 : : }
699 : :
700 : 1066 : void InterruptTorControl()
701 : : {
702 [ + + ]: 1066 : if (gBase) {
703 : 1 : LogPrintf("tor: Thread interrupt\n");
704 : 1 : event_base_once(gBase, -1, EV_TIMEOUT, [](evutil_socket_t, short, void*) {
705 : : event_base_loopbreak(gBase);
706 : : }, nullptr, nullptr);
707 : : }
708 : 1066 : }
709 : :
710 : 1066 : void StopTorControl()
711 : : {
712 [ + + ]: 1066 : if (gBase) {
713 : 1 : torControlThread.join();
714 : 1 : event_base_free(gBase);
715 : 1 : gBase = nullptr;
716 : : }
717 : 1066 : }
718 : :
719 : 15 : CService DefaultOnionServiceTarget(uint16_t port)
720 : : {
721 : 15 : struct in_addr onion_service_target;
722 : 15 : onion_service_target.s_addr = htonl(INADDR_LOOPBACK);
723 : 15 : return {onion_service_target, port};
724 : : }
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