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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 : :
74 : : /****** Low-level TorControlConnection ********/
75 : :
76 : 8 : TorControlConnection::TorControlConnection(CThreadInterrupt& interrupt)
77 [ + - ]: 8 : : m_interrupt(interrupt)
78 : : {
79 : 8 : }
80 : :
81 : 8 : TorControlConnection::~TorControlConnection()
82 : : {
83 : 8 : Disconnect();
84 : 8 : }
85 : :
86 : 15 : bool TorControlConnection::Connect(const std::string& tor_control_center)
87 : : {
88 [ - + ]: 15 : if (m_sock) {
89 : 0 : Disconnect();
90 : : }
91 : :
92 [ + - ]: 15 : std::optional<CService> control_service = Lookup(tor_control_center, DEFAULT_TOR_CONTROL_PORT, fNameLookup);
93 [ - + ]: 15 : if (!control_service.has_value()) {
94 [ # # ]: 0 : LogWarning("tor: Failed to look up control center %s", tor_control_center);
95 : : return false;
96 : : }
97 : :
98 [ + - ]: 15 : m_sock = ConnectDirectly(control_service.value(), /*manual_connection=*/true);
99 [ + + ]: 15 : if (!m_sock) {
100 [ + - ]: 8 : LogWarning("tor: Error connecting to address %s", tor_control_center);
101 : : return false;
102 : : }
103 : :
104 : 7 : m_recv_buffer.clear();
105 : 7 : m_message.Clear();
106 : 7 : m_reply_handlers.clear();
107 : :
108 [ + - + - : 15 : LogDebug(BCLog::TOR, "Successfully connected to Tor control port");
+ - ]
109 : : return true;
110 : 15 : }
111 : :
112 : 15 : void TorControlConnection::Disconnect()
113 : : {
114 [ + + ]: 15 : m_sock.reset();
115 : 15 : m_recv_buffer.clear();
116 : 15 : m_message.Clear();
117 : 15 : m_reply_handlers.clear();
118 : 15 : }
119 : :
120 : 257 : bool TorControlConnection::IsConnected() const
121 : : {
122 [ + + ]: 257 : if (!m_sock) return false;
123 [ + - ]: 242 : std::string errmsg;
124 [ + - ]: 242 : const bool connected{m_sock->IsConnected(errmsg)};
125 [ - + - - ]: 242 : if (!connected && !errmsg.empty()) {
126 [ # # # # : 0 : LogDebug(BCLog::TOR, "Connection check failed: %s", errmsg);
# # ]
127 : : }
128 : 242 : return connected;
129 : 242 : }
130 : :
131 : 239 : bool TorControlConnection::WaitForData(std::chrono::milliseconds timeout)
132 : : {
133 [ + - ]: 239 : if (!m_sock) return false;
134 : :
135 : 239 : Sock::Event event{0};
136 [ + - ]: 239 : if (!m_sock->Wait(timeout, Sock::RecvEvent, &event)) {
137 : : return false;
138 : : }
139 [ - + ]: 239 : if (event & Sock::ErrorEvent) {
140 [ # # ]: 0 : LogDebug(BCLog::TOR, "Socket error detected");
141 : 0 : Disconnect();
142 : 0 : return false;
143 : : }
144 : :
145 : 239 : return (event & Sock::RecvEvent);
146 : : }
147 : :
148 : 229 : bool TorControlConnection::ReceiveAndProcess()
149 : : {
150 [ + - ]: 229 : if (!m_sock) return false;
151 : :
152 : 229 : char buf[4096];
153 : 229 : ssize_t nread = m_sock->Recv(buf, sizeof(buf), MSG_DONTWAIT);
154 : :
155 [ - + ]: 229 : if (nread < 0) {
156 : 0 : int err = WSAGetLastError();
157 [ # # # # ]: 0 : if (err == WSAEWOULDBLOCK || err == WSAEINTR || err == WSAEINPROGRESS) {
158 : : // No data available currently
159 : : return true;
160 : : }
161 [ # # ]: 0 : LogWarning("tor: Error reading from socket: %s", NetworkErrorString(err));
162 : 0 : return false;
163 : : }
164 : :
165 [ + + ]: 229 : if (nread == 0) {
166 [ + - ]: 5 : LogDebug(BCLog::TOR, "End of stream");
167 : 5 : return false;
168 : : }
169 : :
170 [ - + ]: 224 : m_recv_buffer.insert(m_recv_buffer.end(), buf, buf + nread);
171 : 224 : try {
172 [ + + ]: 224 : return ProcessBuffer();
173 [ - + ]: 2 : } catch (const std::runtime_error& e) {
174 [ + - ]: 2 : LogWarning("tor: Error processing receive buffer: %s", e.what());
175 : 2 : return false;
176 : 2 : }
177 : : }
178 : :
179 : 224 : bool TorControlConnection::ProcessBuffer()
180 : : {
181 [ - + ]: 224 : util::LineReader reader(m_recv_buffer, MAX_LINE_LENGTH);
182 : :
183 [ + + ]: 2247 : while (auto line = reader.ReadLine()) {
184 [ - + + + ]: 2024 : if (m_message.lines.size() == MAX_LINE_COUNT) {
185 [ + - + - ]: 2 : throw std::runtime_error(strprintf("Control port reply exceeded %d lines, disconnecting", MAX_LINE_COUNT));
186 : : }
187 : : // Skip short lines
188 [ - + ]: 2023 : if (line->size() < 4) continue;
189 : :
190 : : // Parse: <code><separator><data>
191 : : // <status>(-|+| )<data>
192 [ + - ]: 2023 : m_message.code = ToIntegral<int>(line->substr(0, 3)).value_or(0);
193 : 2023 : m_message.lines.emplace_back(line->substr(4));
194 [ + + ]: 2023 : char separator = (*line)[3]; // '-', '+', or ' '
195 : :
196 [ + + ]: 2023 : if (separator == ' ') {
197 [ - + ]: 11 : if (m_message.code >= 600) {
198 : : // Async notifications are currently unused
199 : : // Synchronous and asynchronous messages are never interleaved
200 [ # # ]: 0 : LogDebug(BCLog::TOR, "Received async notification %i", m_message.code);
201 [ + - ]: 11 : } else if (!m_reply_handlers.empty()) {
202 : : // Invoke reply handler with message
203 : 11 : m_reply_handlers.front()(*this, m_message);
204 : 11 : m_reply_handlers.pop_front();
205 : : } else {
206 [ # # ]: 0 : LogDebug(BCLog::TOR, "Received unexpected sync reply %i", m_message.code);
207 : : }
208 : 11 : m_message.Clear();
209 : : }
210 : : }
211 : :
212 : 222 : m_recv_buffer.erase(m_recv_buffer.begin(), m_recv_buffer.begin() + reader.Consumed());
213 : 222 : return true;
214 : : }
215 : :
216 : 15 : bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler)
217 : : {
218 [ + - ]: 15 : if (!m_sock) return false;
219 : :
220 : 15 : std::string command = cmd + "\r\n";
221 : 15 : try {
222 [ - + + - ]: 15 : m_sock->SendComplete(std::span<const char>{command}, SOCKET_SEND_TIMEOUT, m_interrupt);
223 [ - - ]: 0 : } catch (const std::runtime_error& e) {
224 [ - - ]: 0 : LogWarning("tor: Error sending command: %s", e.what());
225 : 0 : return false;
226 : 0 : }
227 : :
228 [ + - ]: 15 : m_reply_handlers.push_back(reply_handler);
229 : : return true;
230 : 15 : }
231 : :
232 : : /****** General parsing utilities ********/
233 : :
234 : : /* Split reply line in the form 'AUTH METHODS=...' into a type
235 : : * 'AUTH' and arguments 'METHODS=...'.
236 : : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
237 : : * the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24).
238 : : */
239 : 1021 : std::pair<std::string,std::string> SplitTorReplyLine(const std::string &s)
240 : : {
241 : 1021 : size_t ptr=0;
242 : 1021 : std::string type;
243 [ - + + + : 11153 : while (ptr < s.size() && s[ptr] != ' ') {
+ + ]
244 [ + - ]: 10132 : type.push_back(s[ptr]);
245 : 10132 : ++ptr;
246 : : }
247 [ + + ]: 1021 : if (ptr < s.size())
248 : 17 : ++ptr; // skip ' '
249 [ + - ]: 2042 : return make_pair(type, s.substr(ptr));
250 : 1021 : }
251 : :
252 : : /** Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'.
253 : : * Returns a map of keys to values, or an empty map if there was an error.
254 : : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
255 : : * the server reply formats for PROTOCOLINFO (S3.21), AUTHCHALLENGE (S3.24),
256 : : * and ADD_ONION (S3.27). See also sections 2.1 and 2.3.
257 : : */
258 : 36 : std::map<std::string,std::string> ParseTorReplyMapping(const std::string &s)
259 : : {
260 : 36 : std::map<std::string,std::string> mapping;
261 : 36 : size_t ptr=0;
262 [ - + + + ]: 74 : while (ptr < s.size()) {
263 : 47 : std::string key, value;
264 [ - + + + : 304 : while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
+ + + + ]
265 [ + - ]: 257 : key.push_back(s[ptr]);
266 : 257 : ++ptr;
267 : : }
268 [ + + ]: 47 : if (ptr == s.size()) // unexpected end of line
269 : 3 : return std::map<std::string,std::string>();
270 [ + + ]: 44 : if (s[ptr] == ' ') // The remaining string is an OptArguments
271 : : break;
272 : 39 : ++ptr; // skip '='
273 [ - + + + ]: 39 : if (ptr < s.size() && s[ptr] == '"') { // Quoted string
274 : 20 : ++ptr; // skip opening '"'
275 : 20 : bool escape_next = false;
276 [ - + + + : 240 : while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
+ + + + ]
277 : : // Repeated backslashes must be interpreted as pairs
278 [ + + + + ]: 220 : escape_next = (s[ptr] == '\\' && !escape_next);
279 [ + - ]: 220 : value.push_back(s[ptr]);
280 : 220 : ++ptr;
281 : : }
282 [ + + ]: 20 : if (ptr == s.size()) // unexpected end of line
283 : 1 : return std::map<std::string,std::string>();
284 : 19 : ++ptr; // skip closing '"'
285 : : /**
286 : : * Unescape value. Per https://spec.torproject.org/control-spec section 2.1.1:
287 : : *
288 : : * For future-proofing, controller implementers MAY use the following
289 : : * rules to be compatible with buggy Tor implementations and with
290 : : * future ones that implement the spec as intended:
291 : : *
292 : : * Read \n \t \r and \0 ... \377 as C escapes.
293 : : * Treat a backslash followed by any other character as that character.
294 : : */
295 : 19 : std::string escaped_value;
296 [ - + + + ]: 199 : for (size_t i = 0; i < value.size(); ++i) {
297 [ + + ]: 180 : if (value[i] == '\\') {
298 : : // This will always be valid, because if the QuotedString
299 : : // ended in an odd number of backslashes, then the parser
300 : : // would already have returned above, due to a missing
301 : : // terminating double-quote.
302 : 23 : ++i;
303 [ + + ]: 23 : if (value[i] == 'n') {
304 [ + - ]: 1 : escaped_value.push_back('\n');
305 [ + + ]: 22 : } else if (value[i] == 't') {
306 [ + - ]: 1 : escaped_value.push_back('\t');
307 [ + + ]: 21 : } else if (value[i] == 'r') {
308 [ + - ]: 1 : escaped_value.push_back('\r');
309 [ + + + + ]: 20 : } else if ('0' <= value[i] && value[i] <= '7') {
310 : : size_t j;
311 : : // Octal escape sequences have a limit of three octal digits,
312 : : // but terminate at the first character that is not a valid
313 : : // octal digit if encountered sooner.
314 [ + + + + : 21 : for (j = 1; j < 3 && (i+j) < value.size() && '0' <= value[i+j] && value[i+j] <= '7'; ++j) {}
+ - + + ]
315 : : // Tor restricts first digit to 0-3 for three-digit octals.
316 : : // A leading digit of 4-7 would therefore be interpreted as
317 : : // a two-digit octal.
318 [ + + + + ]: 11 : if (j == 3 && value[i] > '3') {
319 : 1 : j--;
320 : : }
321 : 11 : const auto end{i + j};
322 : 11 : uint8_t val{0};
323 [ + + ]: 31 : while (i < end) {
324 : 20 : val *= 8;
325 : 20 : val += value[i++] - '0';
326 : : }
327 [ + - ]: 11 : escaped_value.push_back(char(val));
328 : : // Account for automatic incrementing at loop end
329 : 11 : --i;
330 : : } else {
331 [ + - ]: 9 : escaped_value.push_back(value[i]);
332 : : }
333 : : } else {
334 [ + - ]: 157 : escaped_value.push_back(value[i]);
335 : : }
336 : : }
337 [ + - ]: 38 : value = escaped_value;
338 : 19 : } else { // Unquoted value. Note that values can contain '=' at will, just no spaces
339 [ - + + + : 267 : while (ptr < s.size() && s[ptr] != ' ') {
+ + ]
340 [ + - ]: 248 : value.push_back(s[ptr]);
341 : 248 : ++ptr;
342 : : }
343 : : }
344 [ - + + + : 38 : if (ptr < s.size() && s[ptr] == ' ')
+ - ]
345 : 11 : ++ptr; // skip ' ' after key=value
346 [ + - + - ]: 76 : mapping[key] = value;
347 : 47 : }
348 : 32 : return mapping;
349 : 36 : }
350 : :
351 : 8 : TorController::TorController(const std::string& tor_control_center, const CService& target)
352 [ - + ]: 8 : : m_tor_control_center(tor_control_center),
353 [ + - ]: 8 : m_conn(m_interrupt),
354 [ + - ]: 8 : m_reconnect(true),
355 [ + - ]: 8 : m_reconnect_timeout(RECONNECT_TIMEOUT_START),
356 [ - + + - : 16 : m_target(target)
+ - ]
357 : : {
358 : : // Read service private key if cached
359 [ + - + - ]: 8 : std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
360 [ + + ]: 8 : if (pkf.first) {
361 [ + - + - : 12 : LogDebug(BCLog::TOR, "Reading cached private key from %s", fs::PathToString(GetPrivateKeyFile()));
+ - + - ]
362 [ + - ]: 4 : m_private_key = pkf.second;
363 : : }
364 [ + - ]: 16 : m_thread = std::thread(&util::TraceThread, "torcontrol", [this] { ThreadControl(); });
365 : 8 : }
366 : :
367 : 8 : TorController::~TorController()
368 : : {
369 : 8 : Interrupt();
370 : 8 : Join();
371 [ - + ]: 8 : if (m_service.IsValid()) {
372 : 0 : RemoveLocal(m_service);
373 : : }
374 : 16 : }
375 : :
376 : 16 : void TorController::Interrupt()
377 : : {
378 : 16 : m_reconnect = false;
379 : 16 : m_interrupt();
380 : 16 : }
381 : :
382 : 16 : void TorController::Join()
383 : : {
384 [ + + ]: 16 : if (m_thread.joinable()) {
385 : 8 : m_thread.join();
386 : : }
387 : 16 : }
388 : :
389 : 8 : void TorController::ThreadControl()
390 : : {
391 [ + - ]: 8 : LogDebug(BCLog::TOR, "Entering Tor control thread");
392 : :
393 [ + - ]: 247 : while (!m_interrupt) {
394 : : // Try to connect if not connected already
395 [ + + ]: 247 : if (!m_conn.IsConnected()) {
396 [ + - ]: 15 : LogDebug(BCLog::TOR, "Attempting to connect to Tor control port %s", m_tor_control_center);
397 : :
398 [ + + ]: 15 : if (!m_conn.Connect(m_tor_control_center)) {
399 : 8 : LogWarning("tor: Initiating connection to Tor control port %s failed", m_tor_control_center);
400 [ + - ]: 8 : if (!m_reconnect) {
401 : : break;
402 : : }
403 : : // Wait before retrying with exponential backoff
404 [ + - ]: 8 : LogDebug(BCLog::TOR, "Retrying in %.1f seconds", m_reconnect_timeout.count());
405 [ - + ]: 8 : if (!m_interrupt.sleep_for(std::chrono::duration_cast<std::chrono::milliseconds>(m_reconnect_timeout))) {
406 : : break;
407 : : }
408 : 0 : m_reconnect_timeout = std::min(m_reconnect_timeout * RECONNECT_TIMEOUT_EXP, RECONNECT_TIMEOUT_MAX);
409 : 0 : continue;
410 : : }
411 : : // Successfully connected, reset timeout and trigger connected callback
412 : 7 : m_reconnect_timeout = RECONNECT_TIMEOUT_START;
413 : 7 : connected_cb(m_conn);
414 : : }
415 : : // Wait for data with a timeout
416 [ + + ]: 239 : if (!m_conn.WaitForData(std::chrono::seconds(1))) {
417 : : // Check if still connected
418 [ - + ]: 10 : if (!m_conn.IsConnected()) {
419 [ # # ]: 0 : LogDebug(BCLog::TOR, "Lost connection to Tor control port");
420 : 0 : disconnected_cb(m_conn);
421 : 0 : continue;
422 : : }
423 : : // Just a timeout, continue waiting
424 : 10 : continue;
425 : : }
426 : : // Process incoming data
427 [ + + ]: 229 : if (!m_conn.ReceiveAndProcess()) {
428 : 7 : disconnected_cb(m_conn);
429 : : }
430 : : }
431 [ + - ]: 8 : LogDebug(BCLog::TOR, "Exited Tor control thread");
432 : 8 : }
433 : :
434 : 2 : void TorController::get_socks_cb(TorControlConnection& _conn, const TorControlReply& reply)
435 : : {
436 : : // NOTE: We can only get here if -onion is unset
437 [ + - ]: 2 : std::string socks_location;
438 [ + - ]: 2 : if (reply.code == TOR_REPLY_OK) {
439 [ + + ]: 6 : for (const auto& line : reply.lines) {
440 [ - + + + ]: 4 : if (line.starts_with("net/listeners/socks=")) {
441 [ + - ]: 2 : const std::string port_list_str = line.substr(20);
442 [ - + + - ]: 2 : std::vector<std::string> port_list = SplitString(port_list_str, ' ');
443 : :
444 [ + - ]: 2 : for (auto& portstr : port_list) {
445 [ - + ]: 2 : if (portstr.empty()) continue;
446 [ - + - - : 4 : if ((portstr[0] == '"' || portstr[0] == '\'') && portstr.size() >= 2 && (*portstr.rbegin() == portstr[0])) {
+ - + - ]
447 [ + - ]: 2 : portstr = portstr.substr(1, portstr.size() - 2);
448 [ - + ]: 2 : if (portstr.empty()) continue;
449 : : }
450 [ + - ]: 2 : socks_location = portstr;
451 [ - + - + ]: 2 : if (portstr.starts_with("127.0.0.1:")) {
452 : : // Prefer localhost - ignore other ports
453 : : break;
454 : : }
455 : : }
456 : 2 : }
457 : : }
458 [ + - ]: 2 : if (!socks_location.empty()) {
459 [ + - + - : 2 : LogDebug(BCLog::TOR, "Get SOCKS port command yielded %s", socks_location);
+ - ]
460 : : } else {
461 [ # # ]: 0 : LogWarning("tor: Get SOCKS port command returned nothing");
462 : : }
463 [ # # ]: 0 : } else if (reply.code == TOR_REPLY_UNRECOGNIZED) {
464 [ # # ]: 0 : LogWarning("tor: Get SOCKS port command failed with unrecognized command (You probably should upgrade Tor)");
465 : : } else {
466 [ # # ]: 0 : LogWarning("tor: Get SOCKS port command failed; error code %d", reply.code);
467 : : }
468 : :
469 [ + - ]: 2 : CService resolved;
470 [ + - + - ]: 2 : Assume(!resolved.IsValid());
471 [ + - ]: 2 : if (!socks_location.empty()) {
472 [ + - + - ]: 4 : resolved = LookupNumeric(socks_location, DEFAULT_TOR_SOCKS_PORT);
473 : : }
474 [ + - - + ]: 2 : if (!resolved.IsValid()) {
475 : : // Fallback to old behaviour
476 [ # # # # : 0 : resolved = LookupNumeric("127.0.0.1", DEFAULT_TOR_SOCKS_PORT);
# # ]
477 : : }
478 : :
479 [ + - + - ]: 2 : Assume(resolved.IsValid());
480 [ + - + - : 2 : LogDebug(BCLog::TOR, "Configuring onion proxy for %s", resolved.ToStringAddrPort());
+ - + - ]
481 : :
482 : : // Add Tor as proxy for .onion addresses.
483 : : // Enable stream isolation to prevent connection correlation and enhance privacy, by forcing a different Tor circuit for every connection.
484 : : // 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).
485 : 2 : Proxy addrOnion = Proxy(resolved, /*tor_stream_isolation=*/ true);
486 [ + - ]: 2 : SetProxy(NET_ONION, addrOnion);
487 : :
488 [ + - + - ]: 2 : const auto onlynets = gArgs.GetArgs("-onlynet");
489 : :
490 : 2 : const bool onion_allowed_by_onlynet{
491 [ - + - - ]: 2 : onlynets.empty() ||
492 [ # # ]: 0 : std::any_of(onlynets.begin(), onlynets.end(), [](const auto& n) {
493 : 0 : return ParseNetwork(n) == NET_ONION;
494 : 4 : })};
495 : :
496 : 2 : if (onion_allowed_by_onlynet) {
497 : : // If NET_ONION is reachable, then the below is a noop.
498 : : //
499 : : // If NET_ONION is not reachable, then none of -proxy or -onion was given.
500 : : // Since we are here, then -torcontrol and -torpassword were given.
501 [ + - ]: 2 : g_reachable_nets.Add(NET_ONION);
502 : : }
503 : 4 : }
504 : :
505 : 3 : static std::string MakeAddOnionCmd(const std::string& private_key, const std::string& target, bool enable_pow)
506 : : {
507 : : // Note that the 'virtual' port is always the default port to avoid decloaking nodes using other ports.
508 : 3 : return strprintf("ADD_ONION %s%s Port=%i,%s",
509 : : private_key,
510 [ + + ]: 3 : enable_pow ? " PoWDefensesEnabled=1" : "",
511 [ + + ]: 3 : Params().GetDefaultPort(),
512 : 3 : target);
513 : : }
514 : :
515 : 3 : void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlReply& reply, bool pow_was_enabled)
516 : : {
517 [ + + ]: 3 : if (reply.code == TOR_REPLY_OK) {
518 [ + - + + ]: 3 : LogDebug(BCLog::TOR, "ADD_ONION successful (PoW defenses %s)", pow_was_enabled ? "enabled" : "disabled");
519 [ + + ]: 6 : for (const std::string &s : reply.lines) {
520 : 4 : std::map<std::string,std::string> m = ParseTorReplyMapping(s);
521 [ + - ]: 4 : std::map<std::string,std::string>::iterator i;
522 [ + - + + ]: 8 : if ((i = m.find("ServiceID")) != m.end())
523 [ + - ]: 2 : m_service_id = i->second;
524 [ + - - + ]: 8 : if ((i = m.find("PrivateKey")) != m.end())
525 [ - - ]: 4 : m_private_key = i->second;
526 : 4 : }
527 [ - + ]: 2 : if (m_service_id.empty()) {
528 : 0 : LogWarning("tor: Error parsing ADD_ONION parameters:");
529 [ # # ]: 0 : for (const std::string &s : reply.lines) {
530 [ # # # # ]: 0 : LogWarning(" %s", SanitizeString(s));
531 : : }
532 : : return;
533 : : }
534 [ + - + - : 2 : m_service = LookupNumeric(std::string(m_service_id+".onion"), Params().GetDefaultPort());
+ - ]
535 [ + - ]: 2 : LogInfo("Got tor service ID %s, advertising service %s", m_service_id, m_service.ToStringAddrPort());
536 [ + - + - ]: 4 : if (WriteBinaryFile(GetPrivateKeyFile(), m_private_key)) {
537 [ + - - + : 6 : LogDebug(BCLog::TOR, "Cached service private key to %s", fs::PathToString(GetPrivateKeyFile()));
+ - ]
538 : : } else {
539 [ # # # # ]: 0 : LogWarning("tor: Error writing service private key to %s", fs::PathToString(GetPrivateKeyFile()));
540 : : }
541 : 2 : AddLocal(m_service, LOCAL_MANUAL);
542 : : // ... onion requested - keep connection open
543 [ - + ]: 1 : } else if (reply.code == TOR_REPLY_UNRECOGNIZED) {
544 : 0 : LogWarning("tor: Add onion failed with unrecognized command (You probably need to upgrade Tor)");
545 [ + - + - ]: 1 : } else if (pow_was_enabled && reply.code == TOR_REPLY_SYNTAX_ERROR) {
546 [ + - ]: 1 : LogDebug(BCLog::TOR, "ADD_ONION failed with PoW defenses, retrying without");
547 [ + - + - ]: 2 : _conn.Command(MakeAddOnionCmd(m_private_key, m_target.ToStringAddrPort(), /*enable_pow=*/false),
548 [ + - ]: 2 : [this](TorControlConnection& conn, const TorControlReply& reply) {
549 : 1 : add_onion_cb(conn, reply, /*pow_was_enabled=*/false);
550 : : });
551 : : } else {
552 : 0 : LogWarning("tor: Add onion failed; error code %d", reply.code);
553 : : }
554 : : }
555 : :
556 : 2 : void TorController::auth_cb(TorControlConnection& _conn, const TorControlReply& reply)
557 : : {
558 [ + - ]: 2 : if (reply.code == TOR_REPLY_OK) {
559 [ + - ]: 2 : LogDebug(BCLog::TOR, "Authentication successful");
560 : :
561 : : // Now that we know Tor is running setup the proxy for onion addresses
562 : : // if -onion isn't set to something else.
563 [ + - + - : 2 : if (gArgs.GetArg("-onion", "") == "") {
+ - ]
564 [ + - + - ]: 4 : _conn.Command("GETINFO net/listeners/socks", std::bind_front(&TorController::get_socks_cb, this));
565 : : }
566 : :
567 : : // Finally - now create the service
568 [ + + ]: 2 : if (m_private_key.empty()) { // No private key, generate one
569 : 1 : m_private_key = "NEW:ED25519-V3"; // Explicitly request key type - see issue #9214
570 : : }
571 : : // Request onion service, redirect port.
572 [ + - + - ]: 4 : _conn.Command(MakeAddOnionCmd(m_private_key, m_target.ToStringAddrPort(), /*enable_pow=*/true),
573 [ + - ]: 4 : [this](TorControlConnection& conn, const TorControlReply& reply) {
574 : 2 : add_onion_cb(conn, reply, /*pow_was_enabled=*/true);
575 : : });
576 : : } else {
577 : 0 : LogWarning("tor: Authentication failed");
578 : : }
579 : 2 : }
580 : :
581 : : /** Compute Tor SAFECOOKIE response.
582 : : *
583 : : * ServerHash is computed as:
584 : : * HMAC-SHA256("Tor safe cookie authentication server-to-controller hash",
585 : : * CookieString | ClientNonce | ServerNonce)
586 : : * (with the HMAC key as its first argument)
587 : : *
588 : : * After a controller sends a successful AUTHCHALLENGE command, the
589 : : * next command sent on the connection must be an AUTHENTICATE command,
590 : : * and the only authentication string which that AUTHENTICATE command
591 : : * will accept is:
592 : : *
593 : : * HMAC-SHA256("Tor safe cookie authentication controller-to-server hash",
594 : : * CookieString | ClientNonce | ServerNonce)
595 : : *
596 : : */
597 : 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)
598 : : {
599 : 0 : CHMAC_SHA256 computeHash((const uint8_t*)key.data(), key.size());
600 : 0 : std::vector<uint8_t> computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0);
601 [ # # ]: 0 : computeHash.Write(cookie.data(), cookie.size());
602 [ # # ]: 0 : computeHash.Write(client_nonce.data(), client_nonce.size());
603 [ # # ]: 0 : computeHash.Write(server_nonce.data(), server_nonce.size());
604 [ # # ]: 0 : computeHash.Finalize(computedHash.data());
605 : 0 : return computedHash;
606 : 0 : }
607 : :
608 : 0 : void TorController::authchallenge_cb(TorControlConnection& _conn, const TorControlReply& reply)
609 : : {
610 [ # # ]: 0 : if (reply.code == TOR_REPLY_OK) {
611 [ # # ]: 0 : LogDebug(BCLog::TOR, "SAFECOOKIE authentication challenge successful");
612 [ # # ]: 0 : if (reply.lines.empty()) {
613 : 0 : LogWarning("tor: AUTHCHALLENGE reply was empty");
614 : 0 : return;
615 : : }
616 : 0 : std::pair<std::string,std::string> l = SplitTorReplyLine(reply.lines[0]);
617 [ # # ]: 0 : if (l.first == "AUTHCHALLENGE") {
618 [ # # ]: 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
619 [ # # ]: 0 : if (m.empty()) {
620 [ # # # # : 0 : LogWarning("tor: Error parsing AUTHCHALLENGE parameters: %s", SanitizeString(l.second));
# # ]
621 : 0 : return;
622 : : }
623 [ # # # # : 0 : std::vector<uint8_t> server_hash = ParseHex(m["SERVERHASH"]);
# # # # ]
624 [ # # # # : 0 : std::vector<uint8_t> server_nonce = ParseHex(m["SERVERNONCE"]);
# # # # ]
625 [ # # # # : 0 : LogDebug(BCLog::TOR, "AUTHCHALLENGE ServerHash %s ServerNonce %s", HexStr(server_hash), HexStr(server_nonce));
# # # # #
# # # ]
626 [ # # # # ]: 0 : if (server_nonce.size() != 32) {
627 [ # # ]: 0 : LogWarning("tor: ServerNonce is not 32 bytes, as required by spec");
628 : : return;
629 : : }
630 : :
631 [ # # # # : 0 : std::vector<uint8_t> computed_server_hash = ComputeResponse(TOR_SAFE_SERVERKEY, m_cookie, m_client_nonce, server_nonce);
# # # # ]
632 [ # # ]: 0 : if (computed_server_hash != server_hash) {
633 [ # # # # : 0 : LogWarning("tor: ServerHash %s does not match expected ServerHash %s", HexStr(server_hash), HexStr(computed_server_hash));
# # # # ]
634 : 0 : return;
635 : : }
636 : :
637 [ # # # # : 0 : std::vector<uint8_t> computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, m_cookie, m_client_nonce, server_nonce);
# # # # #
# ]
638 [ # # # # : 0 : _conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind_front(&TorController::auth_cb, this));
# # # # ]
639 : 0 : } else {
640 [ # # ]: 0 : LogWarning("tor: Invalid reply to AUTHCHALLENGE");
641 : : }
642 : 0 : } else {
643 : 0 : LogWarning("tor: SAFECOOKIE authentication challenge failed");
644 : : }
645 : : }
646 : :
647 : 4 : void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorControlReply& reply)
648 : : {
649 [ + - ]: 4 : if (reply.code == TOR_REPLY_OK) {
650 : 4 : std::set<std::string> methods;
651 : 4 : std::string cookiefile;
652 : : /*
653 : : * 250-AUTH METHODS=COOKIE,SAFECOOKIE COOKIEFILE="/home/x/.tor/control_auth_cookie"
654 : : * 250-AUTH METHODS=NULL
655 : : * 250-AUTH METHODS=HASHEDPASSWORD
656 : : */
657 [ + + ]: 1015 : for (const std::string &s : reply.lines) {
658 [ + - ]: 1011 : std::pair<std::string,std::string> l = SplitTorReplyLine(s);
659 [ + + ]: 1011 : if (l.first == "AUTH") {
660 [ + - ]: 3 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
661 [ + - ]: 3 : std::map<std::string,std::string>::iterator i;
662 [ + - + - ]: 6 : if ((i = m.find("METHODS")) != m.end()) {
663 [ - + + - ]: 3 : std::vector<std::string> m_vec = SplitString(i->second, ',');
664 [ + - ]: 6 : methods = std::set<std::string>(m_vec.begin(), m_vec.end());
665 : 3 : }
666 [ + - - + ]: 6 : if ((i = m.find("COOKIEFILE")) != m.end())
667 [ - - ]: 3 : cookiefile = i->second;
668 [ + + ]: 1011 : } else if (l.first == "VERSION") {
669 [ + - ]: 2 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
670 [ + - ]: 2 : std::map<std::string,std::string>::iterator i;
671 [ + - + - ]: 4 : if ((i = m.find("Tor")) != m.end()) {
672 [ + - + - : 2 : LogDebug(BCLog::TOR, "Connected to Tor version %s", i->second);
+ - ]
673 : : }
674 : 2 : }
675 : 1011 : }
676 [ + + ]: 7 : for (const std::string &s : methods) {
677 [ + - + - : 3 : LogDebug(BCLog::TOR, "Supported authentication method: %s", s);
+ - ]
678 : : }
679 : : // Prefer NULL, otherwise SAFECOOKIE. If a password is provided, use HASHEDPASSWORD
680 : : /* Authentication:
681 : : * cookie: hex-encoded ~/.tor/control_auth_cookie
682 : : * password: "password"
683 : : */
684 [ + - + - : 8 : std::string torpassword = gArgs.GetArg("-torpassword", "");
+ - ]
685 [ - + ]: 4 : if (!torpassword.empty()) {
686 [ # # # # ]: 0 : if (methods.contains("HASHEDPASSWORD")) {
687 [ # # # # : 0 : LogDebug(BCLog::TOR, "Using HASHEDPASSWORD authentication");
# # ]
688 [ # # # # : 0 : ReplaceAll(torpassword, "\"", "\\\"");
# # ]
689 [ # # # # : 0 : _conn.Command("AUTHENTICATE \"" + torpassword + "\"", std::bind_front(&TorController::auth_cb, this));
# # ]
690 : : } else {
691 [ # # ]: 0 : LogWarning("tor: Password provided with -torpassword, but HASHEDPASSWORD authentication is not available");
692 : : }
693 [ + - + + ]: 4 : } else if (methods.contains("NULL")) {
694 [ + - + - : 3 : LogDebug(BCLog::TOR, "Using NULL authentication");
+ - ]
695 [ + - + - : 6 : _conn.Command("AUTHENTICATE", std::bind_front(&TorController::auth_cb, this));
+ - ]
696 [ + - - + ]: 1 : } else if (methods.contains("SAFECOOKIE")) {
697 : : // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie
698 [ # # # # : 0 : LogDebug(BCLog::TOR, "Using SAFECOOKIE authentication, reading cookie authentication from %s", cookiefile);
# # ]
699 [ # # # # ]: 0 : std::pair<bool,std::string> status_cookie = ReadBinaryFile(fs::PathFromString(cookiefile), TOR_COOKIE_SIZE);
700 [ # # # # ]: 0 : if (status_cookie.first && status_cookie.second.size() == TOR_COOKIE_SIZE) {
701 : : // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), std::bind_front(&TorController::auth_cb, this));
702 [ # # # # ]: 0 : m_cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
703 [ # # # # ]: 0 : m_client_nonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
704 [ # # ]: 0 : GetRandBytes(m_client_nonce);
705 [ # # # # : 0 : _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(m_client_nonce), std::bind_front(&TorController::authchallenge_cb, this));
# # # # #
# ]
706 : : } else {
707 [ # # ]: 0 : if (status_cookie.first) {
708 [ # # ]: 0 : LogWarning("tor: Authentication cookie %s is not exactly %i bytes, as is required by the spec", cookiefile, TOR_COOKIE_SIZE);
709 : : } else {
710 [ # # ]: 0 : LogWarning("tor: Authentication cookie %s could not be opened (check permissions)", cookiefile);
711 : : }
712 : : }
713 [ + - - + ]: 1 : } else if (methods.contains("HASHEDPASSWORD")) {
714 [ # # ]: 0 : LogWarning("tor: The only supported authentication mechanism left is password, but no password provided with -torpassword");
715 : : } else {
716 [ + - ]: 4 : LogWarning("tor: No supported authentication method");
717 : : }
718 : 4 : } else {
719 : 0 : LogWarning("tor: Requesting protocol info failed");
720 : : }
721 : 4 : }
722 : :
723 : 7 : void TorController::connected_cb(TorControlConnection& _conn)
724 : : {
725 : 7 : m_reconnect_timeout = RECONNECT_TIMEOUT_START;
726 : : // First send a PROTOCOLINFO command to figure out what authentication is expected
727 [ + - + - : 7 : if (!_conn.Command("PROTOCOLINFO 1", std::bind_front(&TorController::protocolinfo_cb, this)))
- + ]
728 : 0 : LogWarning("tor: Error sending initial protocolinfo command");
729 : 7 : }
730 : :
731 : 7 : void TorController::disconnected_cb(TorControlConnection& _conn)
732 : : {
733 : : // Stop advertising service when disconnected
734 [ - + ]: 7 : if (m_service.IsValid())
735 : 0 : RemoveLocal(m_service);
736 : 7 : m_service = CService();
737 [ + - ]: 7 : if (!m_reconnect)
738 : : return;
739 : :
740 [ + - ]: 7 : LogDebug(BCLog::TOR, "Not connected to Tor control port %s, will retry", m_tor_control_center);
741 : 7 : _conn.Disconnect();
742 : : }
743 : :
744 : 16 : fs::path TorController::GetPrivateKeyFile()
745 : : {
746 [ + - ]: 48 : return gArgs.GetDataDirNet() / "onion_v3_private_key";
747 : : }
748 : :
749 : 19 : CService DefaultOnionServiceTarget(uint16_t port)
750 : : {
751 : 19 : struct in_addr onion_service_target;
752 : 19 : onion_service_target.s_addr = htonl(INADDR_LOOPBACK);
753 : 19 : return {onion_service_target, port};
754 : : }
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