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1 : : // Copyright (c) 2015-present 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 <net.h>
14 : : #include <netaddress.h>
15 : : #include <netbase.h>
16 : : #include <random.h>
17 : : #include <tinyformat.h>
18 : : #include <util/check.h>
19 : : #include <util/fs.h>
20 : : #include <util/log.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 <chrono>
30 : : #include <cstdint>
31 : : #include <cstdlib>
32 : : #include <deque>
33 : : #include <functional>
34 : : #include <map>
35 : : #include <optional>
36 : : #include <set>
37 : : #include <thread>
38 : : #include <utility>
39 : : #include <vector>
40 : :
41 : : using util::ReplaceAll;
42 : : using util::SplitString;
43 : : using util::ToString;
44 : :
45 : : /** Default control ip and port */
46 : : const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT);
47 : : /** Tor cookie size (from control-spec.txt) */
48 : : constexpr int TOR_COOKIE_SIZE = 32;
49 : : /** Size of client/server nonce for SAFECOOKIE */
50 : : constexpr int TOR_NONCE_SIZE = 32;
51 : : /** For computing server_hash in SAFECOOKIE */
52 : : static const std::string TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash";
53 : : /** For computing clientHash in SAFECOOKIE */
54 : : static const std::string TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash";
55 : : /** Exponential backoff configuration - initial timeout in seconds */
56 : : constexpr std::chrono::duration<double> RECONNECT_TIMEOUT_START{1.0};
57 : : /** Exponential backoff configuration - growth factor */
58 : : constexpr double RECONNECT_TIMEOUT_EXP = 1.5;
59 : : /** Maximum reconnect timeout in seconds to prevent excessive delays */
60 : : constexpr std::chrono::duration<double> RECONNECT_TIMEOUT_MAX{600.0};
61 : : /** Maximum length for lines received on TorControlConnection.
62 : : * tor-control-spec.txt mentions that there is explicitly no limit defined to line length,
63 : : * this is belt-and-suspenders sanity limit to prevent memory exhaustion.
64 : : */
65 : : constexpr int MAX_LINE_LENGTH = 100000;
66 : : /** Maximum number of lines received on TorControlConnection per reply to avoid
67 : : * memory exhaustion. The largest expected now is 5 (PROTOCOLINFO), but future
68 : : * changes to this file might need to re-evaluate MAX_LINE_COUNT.
69 : : */
70 : : constexpr int MAX_LINE_COUNT = 1000;
71 : : /** Timeout for socket operations */
72 : : constexpr auto SOCKET_SEND_TIMEOUT = 10s;
73 : : constexpr std::string_view PRIVATE_KEY_NEW{"NEW:ED25519-V3"};
74 : : constexpr std::string_view PRIVATE_KEY_PREFIX{"ED25519-V3:"};
75 : :
76 : : /** Whether the value requests a new Ed25519 v3 key or has the expected key format */
77 : 16 : static bool IsWellFormedPrivateKey(std::string_view key)
78 : : {
79 [ + + ]: 16 : if (key == PRIVATE_KEY_NEW) return true;
80 [ + + ]: 13 : if (!key.starts_with(PRIVATE_KEY_PREFIX)) return false;
81 : 12 : const auto decoded{DecodeBase64(key.substr(PRIVATE_KEY_PREFIX.size()))};
82 [ + + - + : 13 : return decoded && decoded->size() == 64; // A 32-byte secret scalar followed by a 32-byte PRF secret
+ + ]
83 : 12 : }
84 : :
85 : : /****** Low-level TorControlConnection ********/
86 : :
87 : 19 : TorControlConnection::TorControlConnection(CThreadInterrupt& interrupt)
88 [ + - ]: 19 : : m_interrupt(interrupt)
89 : : {
90 : 19 : }
91 : :
92 : 19 : TorControlConnection::~TorControlConnection()
93 : : {
94 : 19 : Disconnect();
95 : 19 : }
96 : :
97 : 24 : bool TorControlConnection::Connect(const std::string& tor_control_center)
98 : : {
99 [ - + ]: 24 : if (m_sock) {
100 : 0 : Disconnect();
101 : : }
102 : :
103 [ + - ]: 24 : std::optional<CService> control_service = Lookup(tor_control_center, DEFAULT_TOR_CONTROL_PORT, fNameLookup);
104 [ - + ]: 24 : if (!control_service.has_value()) {
105 [ # # ]: 0 : LogWarning("tor: Failed to look up control center %s", tor_control_center);
106 : : return false;
107 : : }
108 : :
109 [ + - ]: 24 : m_sock = ConnectDirectly(control_service.value(), /*manual_connection=*/true);
110 [ + + ]: 24 : if (!m_sock) {
111 [ + - ]: 2 : LogWarning("tor: Error connecting to address %s", tor_control_center);
112 : : return false;
113 : : }
114 : :
115 : 22 : m_recv_buffer.clear();
116 : 22 : m_message.Clear();
117 : 22 : m_reply_handlers.clear();
118 : :
119 [ + - + - : 24 : LogDebug(BCLog::TOR, "Successfully connected to Tor control port");
+ - ]
120 : : return true;
121 : 24 : }
122 : :
123 : 42 : void TorControlConnection::Disconnect()
124 : : {
125 [ + + ]: 42 : m_sock.reset();
126 : 42 : m_recv_buffer.clear();
127 : 42 : m_message.Clear();
128 : 42 : m_reply_handlers.clear();
129 : 42 : }
130 : :
131 : 7 : bool TorControlConnection::IsConnected() const
132 : : {
133 [ + - ]: 7 : if (!m_sock) return false;
134 [ + - ]: 7 : std::string errmsg;
135 [ + - ]: 7 : const bool connected{m_sock->IsConnected(errmsg)};
136 [ - + - - ]: 7 : if (!connected && !errmsg.empty()) {
137 [ # # # # : 0 : LogDebug(BCLog::TOR, "Connection check failed: %s", errmsg);
# # ]
138 : : }
139 : 7 : return connected;
140 : 7 : }
141 : :
142 : 475 : bool TorControlConnection::WaitForData(std::chrono::milliseconds timeout)
143 : : {
144 [ + - ]: 475 : if (!m_sock) return false;
145 : :
146 : 475 : Sock::Event event{0};
147 [ + - ]: 475 : if (!m_sock->Wait(timeout, Sock::RecvEvent, &event)) {
148 : : return false;
149 : : }
150 [ - + ]: 475 : if (event & Sock::ErrorEvent) {
151 [ # # ]: 0 : LogDebug(BCLog::TOR, "Socket error detected");
152 : 0 : Disconnect();
153 : 0 : return false;
154 : : }
155 : :
156 : 475 : return (event & Sock::RecvEvent);
157 : : }
158 : :
159 : 468 : bool TorControlConnection::ReceiveAndProcess()
160 : : {
161 [ + - ]: 468 : if (!m_sock) return false;
162 : :
163 : 468 : char buf[4096];
164 : 468 : ssize_t nread = m_sock->Recv(buf, sizeof(buf), MSG_DONTWAIT);
165 : :
166 [ - + ]: 468 : if (nread < 0) {
167 : 0 : int err = WSAGetLastError();
168 [ # # # # ]: 0 : if (err == WSAEWOULDBLOCK || err == WSAEINTR || err == WSAEINPROGRESS) {
169 : : // No data available currently
170 : : return true;
171 : : }
172 [ # # ]: 0 : LogWarning("tor: Error reading from socket: %s", NetworkErrorString(err));
173 : 0 : return false;
174 : : }
175 : :
176 [ + + ]: 468 : if (nread == 0) {
177 [ + - ]: 20 : LogDebug(BCLog::TOR, "End of stream");
178 : 20 : return false;
179 : : }
180 : :
181 [ - + ]: 448 : m_recv_buffer.insert(m_recv_buffer.end(), buf, buf + nread);
182 : 448 : try {
183 [ + + ]: 448 : return ProcessBuffer();
184 [ - + ]: 2 : } catch (const std::runtime_error& e) {
185 [ + - ]: 2 : LogWarning("tor: Error processing receive buffer: %s", e.what());
186 : 2 : return false;
187 : 2 : }
188 : : }
189 : :
190 : 448 : bool TorControlConnection::ProcessBuffer()
191 : : {
192 [ - + ]: 448 : util::LineReader reader(m_recv_buffer, MAX_LINE_LENGTH);
193 : :
194 [ + + ]: 2593 : while (auto line = reader.ReadLine()) {
195 [ - + + + ]: 2146 : if (m_message.lines.size() == MAX_LINE_COUNT) {
196 [ + - + - ]: 2 : throw std::runtime_error(strprintf("Control port reply exceeded %d lines, disconnecting", MAX_LINE_COUNT));
197 : : }
198 : : // Skip short lines
199 [ - + ]: 2145 : if (line->size() < 4) continue;
200 : :
201 : : // Parse: <code><separator><data>
202 : : // <status>(-|+| )<data>
203 [ + - ]: 2145 : m_message.code = ToIntegral<int>(line->substr(0, 3)).value_or(0);
204 : 2145 : m_message.lines.emplace_back(line->substr(4));
205 [ + + ]: 2145 : char separator = (*line)[3]; // '-', '+', or ' '
206 : :
207 [ + + ]: 2145 : if (separator == ' ') {
208 [ - + ]: 62 : if (m_message.code >= 600) {
209 : : // Async notifications are currently unused
210 : : // Synchronous and asynchronous messages are never interleaved
211 [ # # ]: 0 : LogDebug(BCLog::TOR, "Received async notification %i", m_message.code);
212 [ + - ]: 62 : } else if (!m_reply_handlers.empty()) {
213 : : // Invoke reply handler with message
214 : 62 : m_reply_handlers.front()(*this, m_message);
215 : 62 : m_reply_handlers.pop_front();
216 : : } else {
217 [ # # ]: 0 : LogDebug(BCLog::TOR, "Received unexpected sync reply %i", m_message.code);
218 : : }
219 : 62 : m_message.Clear();
220 : : }
221 : : }
222 : :
223 : 446 : m_recv_buffer.erase(m_recv_buffer.begin(), m_recv_buffer.begin() + reader.Consumed());
224 : 446 : return true;
225 : : }
226 : :
227 : 67 : bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler)
228 : : {
229 [ + - ]: 67 : if (!m_sock) return false;
230 : :
231 : 67 : std::string command = cmd + "\r\n";
232 : 67 : try {
233 [ - + + - ]: 67 : m_sock->SendComplete(std::span<const char>{command}, SOCKET_SEND_TIMEOUT, m_interrupt);
234 [ - - ]: 0 : } catch (const std::runtime_error& e) {
235 [ - - ]: 0 : LogWarning("tor: Error sending command: %s", e.what());
236 : 0 : return false;
237 : 0 : }
238 : :
239 [ + - ]: 67 : m_reply_handlers.push_back(reply_handler);
240 : : return true;
241 : 67 : }
242 : :
243 : : /****** General parsing utilities ********/
244 : :
245 : : /* Split reply line in the form 'AUTH METHODS=...' into a type
246 : : * 'AUTH' and arguments 'METHODS=...'.
247 : : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
248 : : * the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24).
249 : : */
250 : 1073 : std::pair<std::string,std::string> SplitTorReplyLine(const std::string &s)
251 : : {
252 : 1073 : size_t ptr=0;
253 : 1073 : std::string type;
254 [ - + + + : 11530 : while (ptr < s.size() && s[ptr] != ' ') {
+ + ]
255 [ + - ]: 10457 : type.push_back(s[ptr]);
256 : 10457 : ++ptr;
257 : : }
258 [ + + ]: 1073 : if (ptr < s.size())
259 : 56 : ++ptr; // skip ' '
260 [ + - ]: 2146 : return make_pair(type, s.substr(ptr));
261 : 1073 : }
262 : :
263 : : /** Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'.
264 : : * Returns a map of keys to values, or an empty map if there was an error.
265 : : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
266 : : * the server reply formats for PROTOCOLINFO (S3.21), AUTHCHALLENGE (S3.24),
267 : : * and ADD_ONION (S3.27). See also sections 2.1 and 2.3.
268 : : */
269 : 87 : std::map<std::string,std::string> ParseTorReplyMapping(const std::string &s)
270 : : {
271 : 87 : std::map<std::string,std::string> mapping;
272 : 87 : size_t ptr=0;
273 [ - + + + ]: 170 : while (ptr < s.size()) {
274 : 98 : std::string key, value;
275 [ - + + + : 678 : while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
+ + + + ]
276 [ + - ]: 580 : key.push_back(s[ptr]);
277 : 580 : ++ptr;
278 : : }
279 [ + + ]: 98 : if (ptr == s.size()) // unexpected end of line
280 : 9 : return std::map<std::string,std::string>();
281 [ + + ]: 89 : if (s[ptr] == ' ') // The remaining string is an OptArguments
282 : : break;
283 : 84 : ++ptr; // skip '='
284 [ - + + + ]: 84 : if (ptr < s.size() && s[ptr] == '"') { // Quoted string
285 : 35 : ++ptr; // skip opening '"'
286 : 35 : bool escape_next = false;
287 [ - + + + : 580 : while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
+ + + + ]
288 : : // Repeated backslashes must be interpreted as pairs
289 [ + + + + ]: 545 : escape_next = (s[ptr] == '\\' && !escape_next);
290 [ + - ]: 545 : value.push_back(s[ptr]);
291 : 545 : ++ptr;
292 : : }
293 [ + + ]: 35 : if (ptr == s.size()) // unexpected end of line
294 : 1 : return std::map<std::string,std::string>();
295 : 34 : ++ptr; // skip closing '"'
296 : : /**
297 : : * Unescape value. Per https://spec.torproject.org/control-spec section 2.1.1:
298 : : *
299 : : * For future-proofing, controller implementers MAY use the following
300 : : * rules to be compatible with buggy Tor implementations and with
301 : : * future ones that implement the spec as intended:
302 : : *
303 : : * Read \n \t \r and \0 ... \377 as C escapes.
304 : : * Treat a backslash followed by any other character as that character.
305 : : */
306 : 34 : std::string escaped_value;
307 [ - + + + ]: 535 : for (size_t i = 0; i < value.size(); ++i) {
308 [ + + ]: 501 : if (value[i] == '\\') {
309 : : // This will always be valid, because if the QuotedString
310 : : // ended in an odd number of backslashes, then the parser
311 : : // would already have returned above, due to a missing
312 : : // terminating double-quote.
313 : 27 : ++i;
314 [ + + ]: 27 : if (value[i] == 'n') {
315 [ + - ]: 3 : escaped_value.push_back('\n');
316 [ + + ]: 24 : } else if (value[i] == 't') {
317 [ + - ]: 1 : escaped_value.push_back('\t');
318 [ + + ]: 23 : } else if (value[i] == 'r') {
319 [ + - ]: 3 : escaped_value.push_back('\r');
320 [ + + + + ]: 20 : } else if ('0' <= value[i] && value[i] <= '7') {
321 : : size_t j;
322 : : // Octal escape sequences have a limit of three octal digits,
323 : : // but terminate at the first character that is not a valid
324 : : // octal digit if encountered sooner.
325 [ + + + + : 21 : for (j = 1; j < 3 && (i+j) < value.size() && '0' <= value[i+j] && value[i+j] <= '7'; ++j) {}
+ - + + ]
326 : : // Tor restricts first digit to 0-3 for three-digit octals.
327 : : // A leading digit of 4-7 would therefore be interpreted as
328 : : // a two-digit octal.
329 [ + + + + ]: 11 : if (j == 3 && value[i] > '3') {
330 : 1 : j--;
331 : : }
332 : 11 : const auto end{i + j};
333 : 11 : uint8_t val{0};
334 [ + + ]: 31 : while (i < end) {
335 : 20 : val *= 8;
336 : 20 : val += value[i++] - '0';
337 : : }
338 [ + - ]: 11 : escaped_value.push_back(char(val));
339 : : // Account for automatic incrementing at loop end
340 : 11 : --i;
341 : : } else {
342 [ + - ]: 9 : escaped_value.push_back(value[i]);
343 : : }
344 : : } else {
345 [ + - ]: 474 : escaped_value.push_back(value[i]);
346 : : }
347 : : }
348 [ + - ]: 68 : value = escaped_value;
349 : 34 : } else { // Unquoted value. Note that values can contain '=' at will, just no spaces
350 [ - + + + : 1552 : while (ptr < s.size() && s[ptr] != ' ') {
+ + ]
351 [ + - ]: 1503 : value.push_back(s[ptr]);
352 : 1503 : ++ptr;
353 : : }
354 : : }
355 [ - + + + : 83 : if (ptr < s.size() && s[ptr] == ' ')
+ - ]
356 : 11 : ++ptr; // skip ' ' after key=value
357 [ + - + - ]: 166 : mapping[key] = value;
358 : 98 : }
359 : 77 : return mapping;
360 : 87 : }
361 : :
362 : 19 : TorController::TorController(const std::string& tor_control_center, const CService& target)
363 [ - + ]: 19 : : m_tor_control_center(tor_control_center),
364 [ + - ]: 19 : m_conn(m_interrupt),
365 [ + - ]: 19 : m_reconnect(true),
366 [ + - ]: 19 : m_reconnect_timeout(RECONNECT_TIMEOUT_START),
367 [ - + + - : 38 : m_target(target)
+ - ]
368 : : {
369 : : // Read service private key if cached
370 [ + - + - ]: 19 : std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
371 [ + + ]: 19 : if (pkf.first) {
372 [ + - + - : 9 : LogDebug(BCLog::TOR, "Reading cached private key from %s", fs::PathToString(GetPrivateKeyFile()));
+ - + - ]
373 [ + - ]: 3 : m_private_key = pkf.second;
374 : : }
375 [ + - ]: 38 : m_thread = std::thread(&util::TraceThread, "torcontrol", [this] { ThreadControl(); });
376 : 19 : }
377 : :
378 : 19 : TorController::~TorController()
379 : : {
380 : 19 : Interrupt();
381 : 19 : Join();
382 [ - + ]: 19 : if (m_service.IsValid()) {
383 : 0 : RemoveLocal(m_service);
384 : : }
385 : 38 : }
386 : :
387 : 38 : void TorController::Interrupt()
388 : : {
389 : 38 : m_reconnect = false;
390 : 38 : m_interrupt();
391 : 38 : }
392 : :
393 : 38 : void TorController::Join()
394 : : {
395 [ + + ]: 38 : if (m_thread.joinable()) {
396 : 19 : m_thread.join();
397 : : }
398 : 38 : }
399 : :
400 : 19 : void TorController::ThreadControl()
401 : : {
402 [ + - ]: 19 : LogDebug(BCLog::TOR, "Entering Tor control thread");
403 : :
404 [ + + ]: 43 : while (!m_interrupt) {
405 [ + - ]: 24 : LogDebug(BCLog::TOR, "Attempting to connect to Tor control port %s", m_tor_control_center);
406 [ + + ]: 24 : if (m_conn.Connect(m_tor_control_center)) {
407 : 22 : connected_cb(m_conn);
408 [ + - ]: 497 : while (!m_interrupt) {
409 [ + + ]: 475 : if (!m_conn.WaitForData(std::chrono::seconds(1))) {
410 [ + - ]: 7 : if (m_conn.IsConnected()) continue;
411 [ # # ]: 0 : LogDebug(BCLog::TOR, "Lost connection to Tor control port");
412 : : break;
413 : : }
414 [ + + ]: 468 : if (!m_conn.ReceiveAndProcess()) break;
415 : : }
416 : : } else {
417 : 2 : LogWarning("tor: Initiating connection to Tor control port %s failed", m_tor_control_center);
418 : : }
419 : 24 : disconnected_cb(m_conn);
420 : : }
421 [ + - ]: 19 : LogDebug(BCLog::TOR, "Exited Tor control thread");
422 : 19 : }
423 : :
424 : 15 : void TorController::get_socks_cb(TorControlConnection& _conn, const TorControlReply& reply)
425 : : {
426 : : // NOTE: We can only get here if -onion is unset
427 [ + - ]: 15 : std::string socks_location;
428 [ + - ]: 15 : if (reply.code == TOR_REPLY_OK) {
429 [ + + ]: 45 : for (const auto& line : reply.lines) {
430 [ - + + + ]: 30 : if (line.starts_with("net/listeners/socks=")) {
431 [ + - ]: 15 : const std::string port_list_str = line.substr(20);
432 [ - + + - ]: 15 : std::vector<std::string> port_list = SplitString(port_list_str, ' ');
433 : :
434 [ + - ]: 15 : for (auto& portstr : port_list) {
435 [ - + ]: 15 : if (portstr.empty()) continue;
436 [ - + - - : 30 : if ((portstr[0] == '"' || portstr[0] == '\'') && portstr.size() >= 2 && (*portstr.rbegin() == portstr[0])) {
+ - + - ]
437 [ + - ]: 15 : portstr = portstr.substr(1, portstr.size() - 2);
438 [ - + ]: 15 : if (portstr.empty()) continue;
439 : : }
440 [ + - ]: 15 : socks_location = portstr;
441 [ - + - + ]: 15 : if (portstr.starts_with("127.0.0.1:")) {
442 : : // Prefer localhost - ignore other ports
443 : : break;
444 : : }
445 : : }
446 : 15 : }
447 : : }
448 [ + - ]: 15 : if (!socks_location.empty()) {
449 [ + - + - : 15 : LogDebug(BCLog::TOR, "Get SOCKS port command yielded %s", socks_location);
+ - ]
450 : : } else {
451 [ # # ]: 0 : LogWarning("tor: Get SOCKS port command returned nothing");
452 : : }
453 [ # # ]: 0 : } else if (reply.code == TOR_REPLY_UNRECOGNIZED) {
454 [ # # ]: 0 : LogWarning("tor: Get SOCKS port command failed with unrecognized command (You probably should upgrade Tor)");
455 : : } else {
456 [ # # ]: 0 : LogWarning("tor: Get SOCKS port command failed; error code %d", reply.code);
457 : : }
458 : :
459 [ + - ]: 15 : CService resolved;
460 [ + - + - ]: 15 : Assume(!resolved.IsValid());
461 [ + - ]: 15 : if (!socks_location.empty()) {
462 [ + - + - ]: 30 : resolved = LookupNumeric(socks_location, DEFAULT_TOR_SOCKS_PORT);
463 : : }
464 [ + - - + ]: 15 : if (!resolved.IsValid()) {
465 : : // Fallback to old behaviour
466 [ # # # # : 0 : resolved = LookupNumeric("127.0.0.1", DEFAULT_TOR_SOCKS_PORT);
# # ]
467 : : }
468 : :
469 [ + - + - ]: 15 : Assume(resolved.IsValid());
470 [ + - + - : 15 : LogDebug(BCLog::TOR, "Configuring onion proxy for %s", resolved.ToStringAddrPort());
+ - + - ]
471 : :
472 : : // Add Tor as proxy for .onion addresses.
473 : : // Enable stream isolation to prevent connection correlation and enhance privacy, by forcing a different Tor circuit for every connection.
474 : : // For this to work, the IsolateSOCKSAuth flag must be enabled on SOCKSPort (which is the default, see the IsolateSOCKSAuth section of Tor's manual page).
475 : 15 : Proxy addrOnion = Proxy(resolved, /*tor_stream_isolation=*/ true);
476 [ + - ]: 15 : SetProxy(NET_ONION, addrOnion);
477 : :
478 [ + - + - ]: 15 : const auto onlynets = gArgs.GetArgs("-onlynet");
479 : :
480 : 15 : const bool onion_allowed_by_onlynet{
481 [ - + - - ]: 15 : onlynets.empty() ||
482 [ # # ]: 0 : std::any_of(onlynets.begin(), onlynets.end(), [](const auto& n) {
483 : 0 : return ParseNetwork(n) == NET_ONION;
484 : 30 : })};
485 : :
486 : 15 : if (onion_allowed_by_onlynet) {
487 : : // If NET_ONION is reachable, then the below is a noop.
488 : : //
489 : : // If NET_ONION is not reachable, then none of -proxy or -onion was given.
490 : : // Since we are here, then -torcontrol and -torpassword were given.
491 [ + - ]: 15 : g_reachable_nets.Add(NET_ONION);
492 : : }
493 : 30 : }
494 : :
495 : 14 : static std::string MakeAddOnionCmd(const std::string& private_key, const std::string& target, bool enable_pow)
496 : : {
497 : : // Note that the 'virtual' port is always the default port to avoid decloaking nodes using other ports.
498 : 14 : return strprintf("ADD_ONION %s%s Port=%i,%s",
499 : : private_key,
500 [ + + ]: 14 : enable_pow ? " PoWDefensesEnabled=1" : "",
501 [ + + ]: 14 : Params().GetDefaultPort(),
502 : 14 : target);
503 : : }
504 : :
505 : 14 : void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlReply& reply, bool pow_was_enabled)
506 : : {
507 [ + + ]: 14 : if (reply.code == TOR_REPLY_OK) {
508 [ + - + + ]: 14 : LogDebug(BCLog::TOR, "ADD_ONION successful (PoW defenses %s)", pow_was_enabled ? "enabled" : "disabled");
509 : 13 : std::string service_id;
510 : 13 : std::string private_key;
511 [ + + ]: 37 : for (const std::string &s : reply.lines) {
512 [ + - ]: 29 : std::map<std::string,std::string> m = ParseTorReplyMapping(s);
513 [ + - ]: 29 : std::map<std::string,std::string>::iterator i;
514 [ + - + + ]: 58 : if ((i = m.find("ServiceID")) != m.end())
515 [ + - ]: 11 : service_id = i->second;
516 [ + - + + ]: 58 : if ((i = m.find("PrivateKey")) != m.end()) {
517 [ - + + - : 10 : if (!IsWellFormedPrivateKey(i->second)) { // Never adopt or cache such a key
+ + ]
518 [ + - ]: 5 : LogWarning("tor: ADD_ONION returned a malformed private key");
519 : 5 : return;
520 : : }
521 [ + - ]: 29 : private_key = i->second;
522 : : }
523 : 29 : }
524 [ + + ]: 8 : if (service_id.empty()) {
525 [ + - ]: 2 : LogWarning("tor: Error parsing ADD_ONION parameters:");
526 [ + + ]: 6 : for (const std::string &s : reply.lines) {
527 [ - + + - : 4 : LogWarning(" %s", SanitizeString(s));
+ - ]
528 : : }
529 : : return;
530 : : }
531 [ + - + - : 12 : const auto service{LookupNumeric(service_id + ".onion", Params().GetDefaultPort())};
+ - + - ]
532 [ + + ]: 6 : if (!service.IsTor()) {
533 [ + - ]: 2 : LogWarning("tor: ADD_ONION returned an invalid service ID");
534 : 2 : return;
535 : : }
536 [ + + ]: 4 : if (!private_key.empty()) m_private_key = std::move(private_key);
537 : 4 : m_service = service;
538 [ + - + - ]: 4 : LogInfo("Got tor service ID %s, advertising service %s", service_id, m_service.ToStringAddrPort());
539 [ + - + - : 8 : if (WriteBinaryFile(GetPrivateKeyFile(), m_private_key)) {
+ - ]
540 [ + - + - : 12 : LogDebug(BCLog::TOR, "Cached service private key to %s", fs::PathToString(GetPrivateKeyFile()));
+ - + - ]
541 : : } else {
542 [ # # # # ]: 0 : LogWarning("tor: Error writing service private key to %s", fs::PathToString(GetPrivateKeyFile()));
543 : : }
544 [ + - ]: 4 : AddLocal(m_service, LOCAL_MANUAL);
545 : : // ... onion requested - keep connection open
546 [ - + ]: 16 : } else if (reply.code == TOR_REPLY_UNRECOGNIZED) {
547 : 0 : LogWarning("tor: Add onion failed with unrecognized command (You probably need to upgrade Tor)");
548 [ + - + - ]: 1 : } else if (pow_was_enabled && reply.code == TOR_REPLY_SYNTAX_ERROR) {
549 [ + - ]: 1 : LogDebug(BCLog::TOR, "ADD_ONION failed with PoW defenses, retrying without");
550 [ + - + - ]: 2 : _conn.Command(MakeAddOnionCmd(m_private_key, m_target.ToStringAddrPort(), /*enable_pow=*/false),
551 [ + - ]: 2 : [this](TorControlConnection& conn, const TorControlReply& reply) {
552 : 1 : add_onion_cb(conn, reply, /*pow_was_enabled=*/false);
553 : : });
554 : : } else {
555 : 0 : LogWarning("tor: Add onion failed; error code %d", reply.code);
556 : : }
557 : : }
558 : :
559 : 15 : void TorController::auth_cb(TorControlConnection& _conn, const TorControlReply& reply)
560 : : {
561 [ + - ]: 15 : if (reply.code == TOR_REPLY_OK) {
562 [ + - ]: 15 : LogDebug(BCLog::TOR, "Authentication successful");
563 : :
564 : : // Now that we know Tor is running setup the proxy for onion addresses
565 : : // if -onion isn't set to something else.
566 [ + - + - : 15 : if (gArgs.GetArg("-onion", "") == "") {
+ - ]
567 [ + - + - ]: 30 : _conn.Command("GETINFO net/listeners/socks", std::bind_front(&TorController::get_socks_cb, this));
568 : : }
569 : :
570 : : // Finally - now create the service
571 [ + + ]: 15 : if (m_private_key.empty()) { // No private key, generate one
572 : 9 : m_private_key = PRIVATE_KEY_NEW; // Explicitly request key type - see issue #9214
573 [ - + + + ]: 6 : } else if (!IsWellFormedPrivateKey(m_private_key)) {
574 : : // add_onion_cb() never adopts such a key, so it can only come from the cache file
575 [ - + + - ]: 4 : LogWarning("tor: Refusing to use cached private key %s because it is malformed; remove the file to generate a new key", fs::PathToString(GetPrivateKeyFile()));
576 : 2 : return;
577 : : }
578 : : // Request onion service, redirect port.
579 [ + - + - ]: 26 : _conn.Command(MakeAddOnionCmd(m_private_key, m_target.ToStringAddrPort(), /*enable_pow=*/true),
580 [ + - ]: 26 : [this](TorControlConnection& conn, const TorControlReply& reply) {
581 : 13 : add_onion_cb(conn, reply, /*pow_was_enabled=*/true);
582 : : });
583 : : } else {
584 : 0 : LogWarning("tor: Authentication failed");
585 : : }
586 : : }
587 : :
588 : : /** Compute Tor SAFECOOKIE response.
589 : : *
590 : : * ServerHash is computed as:
591 : : * HMAC-SHA256("Tor safe cookie authentication server-to-controller hash",
592 : : * CookieString | ClientNonce | ServerNonce)
593 : : * (with the HMAC key as its first argument)
594 : : *
595 : : * After a controller sends a successful AUTHCHALLENGE command, the
596 : : * next command sent on the connection must be an AUTHENTICATE command,
597 : : * and the only authentication string which that AUTHENTICATE command
598 : : * will accept is:
599 : : *
600 : : * HMAC-SHA256("Tor safe cookie authentication controller-to-server hash",
601 : : * CookieString | ClientNonce | ServerNonce)
602 : : *
603 : : */
604 : 0 : static std::vector<uint8_t> ComputeResponse(std::string_view key, std::span<const uint8_t> cookie, std::span<const uint8_t> client_nonce, std::span<const uint8_t> server_nonce)
605 : : {
606 : 0 : CHMAC_SHA256 computeHash((const uint8_t*)key.data(), key.size());
607 : 0 : std::vector<uint8_t> computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0);
608 [ # # ]: 0 : computeHash.Write(cookie.data(), cookie.size());
609 [ # # ]: 0 : computeHash.Write(client_nonce.data(), client_nonce.size());
610 [ # # ]: 0 : computeHash.Write(server_nonce.data(), server_nonce.size());
611 [ # # ]: 0 : computeHash.Finalize(computedHash.data());
612 : 0 : return computedHash;
613 : 0 : }
614 : :
615 : 0 : void TorController::authchallenge_cb(TorControlConnection& _conn, const TorControlReply& reply)
616 : : {
617 [ # # ]: 0 : if (reply.code == TOR_REPLY_OK) {
618 [ # # ]: 0 : LogDebug(BCLog::TOR, "SAFECOOKIE authentication challenge successful");
619 [ # # ]: 0 : if (reply.lines.empty()) {
620 : 0 : LogWarning("tor: AUTHCHALLENGE reply was empty");
621 : 0 : return;
622 : : }
623 : 0 : std::pair<std::string,std::string> l = SplitTorReplyLine(reply.lines[0]);
624 [ # # ]: 0 : if (l.first == "AUTHCHALLENGE") {
625 [ # # ]: 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
626 [ # # ]: 0 : if (m.empty()) {
627 [ # # # # : 0 : LogWarning("tor: Error parsing AUTHCHALLENGE parameters: %s", SanitizeString(l.second));
# # ]
628 : 0 : return;
629 : : }
630 [ # # # # : 0 : std::vector<uint8_t> server_hash = ParseHex(m["SERVERHASH"]);
# # # # ]
631 [ # # # # : 0 : std::vector<uint8_t> server_nonce = ParseHex(m["SERVERNONCE"]);
# # # # ]
632 [ # # # # : 0 : LogDebug(BCLog::TOR, "AUTHCHALLENGE ServerHash %s ServerNonce %s", HexStr(server_hash), HexStr(server_nonce));
# # # # #
# # # ]
633 [ # # # # ]: 0 : if (server_nonce.size() != 32) {
634 [ # # ]: 0 : LogWarning("tor: ServerNonce is not 32 bytes, as required by spec");
635 : : return;
636 : : }
637 : :
638 [ # # # # : 0 : std::vector<uint8_t> computed_server_hash = ComputeResponse(TOR_SAFE_SERVERKEY, m_cookie, m_client_nonce, server_nonce);
# # # # ]
639 [ # # ]: 0 : if (computed_server_hash != server_hash) {
640 [ # # # # : 0 : LogWarning("tor: ServerHash %s does not match expected ServerHash %s", HexStr(server_hash), HexStr(computed_server_hash));
# # # # ]
641 : 0 : return;
642 : : }
643 : :
644 [ # # # # : 0 : std::vector<uint8_t> computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, m_cookie, m_client_nonce, server_nonce);
# # # # #
# ]
645 [ # # # # : 0 : _conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind_front(&TorController::auth_cb, this));
# # # # ]
646 : 0 : } else {
647 [ # # ]: 0 : LogWarning("tor: Invalid reply to AUTHCHALLENGE");
648 : : }
649 : 0 : } else {
650 : 0 : LogWarning("tor: SAFECOOKIE authentication challenge failed");
651 : : }
652 : : }
653 : :
654 : 18 : void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorControlReply& reply)
655 : : {
656 [ + + ]: 18 : if (reply.code == TOR_REPLY_OK) {
657 : 17 : std::set<std::string> methods;
658 : 17 : std::string cookiefile;
659 : : /*
660 : : * 250-AUTH METHODS=COOKIE,SAFECOOKIE COOKIEFILE="/home/x/.tor/control_auth_cookie"
661 : : * 250-AUTH METHODS=NULL
662 : : * 250-AUTH METHODS=HASHEDPASSWORD
663 : : */
664 [ + + ]: 1080 : for (const std::string &s : reply.lines) {
665 [ + - ]: 1063 : std::pair<std::string,std::string> l = SplitTorReplyLine(s);
666 [ + + ]: 1063 : if (l.first == "AUTH") {
667 [ + - ]: 16 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
668 [ + - ]: 16 : std::map<std::string,std::string>::iterator i;
669 [ + - + - ]: 32 : if ((i = m.find("METHODS")) != m.end()) {
670 [ - + + - ]: 16 : std::vector<std::string> m_vec = SplitString(i->second, ',');
671 [ + - ]: 32 : methods = std::set<std::string>(m_vec.begin(), m_vec.end());
672 : 16 : }
673 [ + - - + ]: 32 : if ((i = m.find("COOKIEFILE")) != m.end())
674 [ - - ]: 16 : cookiefile = i->second;
675 [ + + ]: 1063 : } else if (l.first == "VERSION") {
676 [ + - ]: 15 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
677 [ + - ]: 15 : std::map<std::string,std::string>::iterator i;
678 [ + - + - ]: 30 : if ((i = m.find("Tor")) != m.end()) {
679 [ + - + - : 15 : LogDebug(BCLog::TOR, "Connected to Tor version %s", i->second);
+ - ]
680 : : }
681 : 15 : }
682 : 1063 : }
683 [ + + ]: 33 : for (const std::string &s : methods) {
684 [ + - + - : 16 : LogDebug(BCLog::TOR, "Supported authentication method: %s", s);
+ - ]
685 : : }
686 : : // Prefer NULL, otherwise SAFECOOKIE. If a password is provided, use HASHEDPASSWORD
687 : : /* Authentication:
688 : : * cookie: hex-encoded ~/.tor/control_auth_cookie
689 : : * password: "password"
690 : : */
691 [ + - + - : 34 : std::string torpassword = gArgs.GetArg("-torpassword", "");
+ - ]
692 [ - + ]: 17 : if (!torpassword.empty()) {
693 [ # # # # ]: 0 : if (methods.contains("HASHEDPASSWORD")) {
694 [ # # # # : 0 : LogDebug(BCLog::TOR, "Using HASHEDPASSWORD authentication");
# # ]
695 [ # # ]: 0 : ReplaceAll(torpassword, "\"", "\\\"");
696 [ # # # # : 0 : _conn.Command("AUTHENTICATE \"" + torpassword + "\"", std::bind_front(&TorController::auth_cb, this));
# # ]
697 : : } else {
698 [ # # ]: 0 : LogWarning("tor: Password provided with -torpassword, but HASHEDPASSWORD authentication is not available");
699 : : }
700 [ + - + + ]: 17 : } else if (methods.contains("NULL")) {
701 [ + - + - : 16 : LogDebug(BCLog::TOR, "Using NULL authentication");
+ - ]
702 [ + - + - : 32 : _conn.Command("AUTHENTICATE", std::bind_front(&TorController::auth_cb, this));
+ - ]
703 [ + - - + ]: 1 : } else if (methods.contains("SAFECOOKIE")) {
704 : : // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie
705 [ # # # # : 0 : LogDebug(BCLog::TOR, "Using SAFECOOKIE authentication, reading cookie authentication from %s", cookiefile);
# # ]
706 [ # # # # ]: 0 : std::pair<bool,std::string> status_cookie = ReadBinaryFile(fs::PathFromString(cookiefile), TOR_COOKIE_SIZE);
707 [ # # # # ]: 0 : if (status_cookie.first && status_cookie.second.size() == TOR_COOKIE_SIZE) {
708 : : // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), std::bind_front(&TorController::auth_cb, this));
709 [ # # # # ]: 0 : m_cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
710 [ # # # # ]: 0 : m_client_nonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
711 [ # # ]: 0 : GetRandBytes(m_client_nonce);
712 [ # # # # : 0 : _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(m_client_nonce), std::bind_front(&TorController::authchallenge_cb, this));
# # # # #
# ]
713 : : } else {
714 [ # # ]: 0 : if (status_cookie.first) {
715 [ # # ]: 0 : LogWarning("tor: Authentication cookie %s is not exactly %i bytes, as is required by the spec", cookiefile, TOR_COOKIE_SIZE);
716 : : } else {
717 [ # # ]: 0 : LogWarning("tor: Authentication cookie %s could not be opened (check permissions)", cookiefile);
718 : : }
719 : : }
720 [ + - - + ]: 1 : } else if (methods.contains("HASHEDPASSWORD")) {
721 [ # # ]: 0 : LogWarning("tor: The only supported authentication mechanism left is password, but no password provided with -torpassword");
722 : : } else {
723 [ + - ]: 17 : LogWarning("tor: No supported authentication method");
724 : : }
725 : 17 : } else {
726 : 1 : LogWarning("tor: Requesting protocol info failed");
727 : : }
728 : 18 : }
729 : :
730 : 22 : void TorController::connected_cb(TorControlConnection& _conn)
731 : : {
732 : 22 : m_reconnect_timeout = RECONNECT_TIMEOUT_START;
733 : : // First send a PROTOCOLINFO command to figure out what authentication is expected
734 [ + - + - : 22 : if (!_conn.Command("PROTOCOLINFO 1", std::bind_front(&TorController::protocolinfo_cb, this)))
- + ]
735 : 0 : LogWarning("tor: Error sending initial protocolinfo command");
736 : 22 : }
737 : :
738 : 24 : void TorController::disconnected_cb(TorControlConnection& _conn)
739 : : {
740 : : // Stop advertising service when disconnected
741 [ + + ]: 24 : if (m_service.IsValid())
742 : 4 : RemoveLocal(m_service);
743 : 24 : m_service = CService();
744 [ + + ]: 24 : if (!m_reconnect)
745 : : return;
746 : :
747 [ + - ]: 23 : LogDebug(BCLog::TOR, "Not connected to Tor control port %s, retrying in %.2f s",
748 : : m_tor_control_center, m_reconnect_timeout.count());
749 : 23 : _conn.Disconnect();
750 : :
751 : 23 : m_interrupt.sleep_for(std::chrono::duration_cast<std::chrono::milliseconds>(m_reconnect_timeout));
752 : 23 : m_reconnect_timeout = std::min(m_reconnect_timeout * RECONNECT_TIMEOUT_EXP, RECONNECT_TIMEOUT_MAX);
753 : : }
754 : :
755 : 32 : fs::path TorController::GetPrivateKeyFile()
756 : : {
757 [ + - ]: 96 : return gArgs.GetDataDirNet() / "onion_v3_private_key";
758 : : }
759 : :
760 : 21 : CService DefaultOnionServiceTarget(uint16_t port)
761 : : {
762 : 21 : struct in_addr onion_service_target;
763 : 21 : onion_service_target.s_addr = htonl(INADDR_LOOPBACK);
764 : 21 : return {onion_service_target, port};
765 : : }
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