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 [ + - ]: 2 : #include <random.h>
18 [ + - ]: 2 : #include <tinyformat.h>
19 : : #include <util/check.h>
20 : : #include <util/fs.h>
21 : : #include <util/readwritefile.h>
22 : : #include <util/strencodings.h>
23 : : #include <util/string.h>
24 : : #include <util/thread.h>
25 : : #include <util/time.h>
26 : :
27 : : #include <algorithm>
28 : : #include <cassert>
29 : : #include <cstdlib>
30 : : #include <deque>
31 : : #include <functional>
32 : : #include <map>
33 : : #include <optional>
34 : : #include <set>
35 : : #include <thread>
36 : : #include <utility>
37 : : #include <vector>
38 : :
39 : : #include <event2/buffer.h>
40 : : #include <event2/bufferevent.h>
41 : : #include <event2/event.h>
42 : : #include <event2/thread.h>
43 : : #include <event2/util.h>
44 : :
45 : : /** Default control ip and port */
46 [ + - ]: 2 : const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT);
47 : : /** Tor cookie size (from control-spec.txt) */
48 : : static const int TOR_COOKIE_SIZE = 32;
49 : : /** Size of client/server nonce for SAFECOOKIE */
50 : : static const int TOR_NONCE_SIZE = 32;
51 : : /** For computing serverHash in SAFECOOKIE */
52 [ + - ]: 2 : static const std::string TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash";
53 : : /** For computing clientHash in SAFECOOKIE */
54 [ + - ]: 2 : static const std::string TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash";
55 : : /** Exponential backoff configuration - initial timeout in seconds */
56 : : static const float RECONNECT_TIMEOUT_START = 1.0;
57 : : /** Exponential backoff configuration - growth factor */
58 : : static const float RECONNECT_TIMEOUT_EXP = 1.5;
59 : : /** Maximum length for lines received on TorControlConnection.
60 : : * tor-control-spec.txt mentions that there is explicitly no limit defined to line length,
61 : : * this is belt-and-suspenders sanity limit to prevent memory exhaustion.
62 : : */
63 : : static const int MAX_LINE_LENGTH = 100000;
64 : : static const uint16_t DEFAULT_TOR_SOCKS_PORT = 9050;
65 : :
66 : : /****** Low-level TorControlConnection ********/
67 : :
68 [ # # # # : 0 : TorControlConnection::TorControlConnection(struct event_base* _base)
# # ]
69 : 0 : : base(_base)
70 : : {
71 : 0 : }
72 : :
73 : 0 : TorControlConnection::~TorControlConnection()
74 : 2 : {
75 [ # # ]: 0 : if (b_conn)
76 [ # # ]: 0 : bufferevent_free(b_conn);
77 : 0 : }
78 : :
79 : 0 : void TorControlConnection::readcb(struct bufferevent *bev, void *ctx)
80 : : {
81 : 0 : TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
82 : 0 : struct evbuffer *input = bufferevent_get_input(bev);
83 [ + - ]: 2 : size_t n_read_out = 0;
84 : : char *line;
85 [ # # ]: 0 : assert(input);
86 : : // If there is not a whole line to read, evbuffer_readln returns nullptr
87 [ # # ]: 0 : while((line = evbuffer_readln(input, &n_read_out, EVBUFFER_EOL_CRLF)) != nullptr)
88 : : {
89 [ # # ]: 0 : std::string s(line, n_read_out);
90 : 0 : free(line);
91 [ # # ]: 0 : if (s.size() < 4) // Short line
92 : 0 : continue;
93 : : // <status>(-|+| )<data><CRLF>
94 [ # # # # : 0 : self->message.code = ToIntegral<int>(s.substr(0, 3)).value_or(0);
# # ]
95 [ # # # # ]: 0 : self->message.lines.push_back(s.substr(4));
96 [ # # ]: 0 : char ch = s[3]; // '-','+' or ' '
97 [ # # ]: 0 : if (ch == ' ') {
98 : : // Final line, dispatch reply and clean up
99 [ # # ]: 0 : if (self->message.code >= 600) {
100 : : // (currently unused)
101 : : // Dispatch async notifications to async handler
102 : : // Synchronous and asynchronous messages are never interleaved
103 : 0 : } else {
104 [ # # ]: 0 : if (!self->reply_handlers.empty()) {
105 : : // Invoke reply handler with message
106 [ # # ]: 0 : self->reply_handlers.front()(*self, self->message);
107 : 0 : self->reply_handlers.pop_front();
108 : 0 : } else {
109 [ # # # # : 0 : LogPrint(BCLog::TOR, "Received unexpected sync reply %i\n", self->message.code);
# # # # #
# ]
110 : : }
111 : : }
112 [ # # ]: 0 : self->message.Clear();
113 : 0 : }
114 [ # # # ]: 0 : }
115 : : // Check for size of buffer - protect against memory exhaustion with very long lines
116 : : // Do this after evbuffer_readln to make sure all full lines have been
117 : : // removed from the buffer. Everything left is an incomplete line.
118 [ # # ]: 0 : if (evbuffer_get_length(input) > MAX_LINE_LENGTH) {
119 [ # # # # : 0 : LogPrintf("tor: Disconnecting because MAX_LINE_LENGTH exceeded\n");
# # ]
120 : 0 : self->Disconnect();
121 : 0 : }
122 : 0 : }
123 : :
124 : 0 : void TorControlConnection::eventcb(struct bufferevent *bev, short what, void *ctx)
125 : : {
126 : 0 : TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
127 [ # # ]: 0 : if (what & BEV_EVENT_CONNECTED) {
128 [ # # # # : 0 : LogPrint(BCLog::TOR, "Successfully connected!\n");
# # # # ]
129 : 0 : self->connected(*self);
130 [ # # ]: 0 : } else if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
131 [ # # ]: 0 : if (what & BEV_EVENT_ERROR) {
132 [ # # # # : 0 : LogPrint(BCLog::TOR, "Error connecting to Tor control socket\n");
# # # # ]
133 : 0 : } else {
134 [ # # # # : 0 : LogPrint(BCLog::TOR, "End of stream\n");
# # # # ]
135 : : }
136 : 0 : self->Disconnect();
137 : 0 : self->disconnected(*self);
138 : 0 : }
139 : 0 : }
140 : :
141 : 0 : bool TorControlConnection::Connect(const std::string& tor_control_center, const ConnectionCB& _connected, const ConnectionCB& _disconnected)
142 : : {
143 [ # # ]: 0 : if (b_conn) {
144 : 0 : Disconnect();
145 : 0 : }
146 : :
147 [ # # ]: 0 : const std::optional<CService> control_service{Lookup(tor_control_center, DEFAULT_TOR_CONTROL_PORT, fNameLookup)};
148 [ # # ]: 0 : if (!control_service.has_value()) {
149 [ # # # # : 0 : LogPrintf("tor: Failed to look up control center %s\n", tor_control_center);
# # ]
150 : 0 : return false;
151 : : }
152 : :
153 : : struct sockaddr_storage control_address;
154 : 0 : socklen_t control_address_len = sizeof(control_address);
155 [ # # # # : 0 : if (!control_service.value().GetSockAddr(reinterpret_cast<struct sockaddr*>(&control_address), &control_address_len)) {
# # ]
156 [ # # # # : 0 : LogPrintf("tor: Error parsing socket address %s\n", tor_control_center);
# # ]
157 : 0 : return false;
158 : : }
159 : :
160 : : // Create a new socket, set up callbacks and enable notification bits
161 [ # # ]: 0 : b_conn = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE);
162 [ # # ]: 0 : if (!b_conn) {
163 : 0 : return false;
164 : : }
165 [ # # ]: 0 : bufferevent_setcb(b_conn, TorControlConnection::readcb, nullptr, TorControlConnection::eventcb, this);
166 [ # # ]: 0 : bufferevent_enable(b_conn, EV_READ|EV_WRITE);
167 [ # # ]: 0 : this->connected = _connected;
168 [ # # ]: 0 : this->disconnected = _disconnected;
169 : :
170 : : // Finally, connect to tor_control_center
171 [ # # # # ]: 0 : if (bufferevent_socket_connect(b_conn, reinterpret_cast<struct sockaddr*>(&control_address), control_address_len) < 0) {
172 [ # # # # : 0 : LogPrintf("tor: Error connecting to address %s\n", tor_control_center);
# # ]
173 : 0 : return false;
174 : : }
175 : 0 : return true;
176 : 0 : }
177 : :
178 : 0 : void TorControlConnection::Disconnect()
179 : : {
180 [ # # ]: 0 : if (b_conn)
181 : 0 : bufferevent_free(b_conn);
182 : 0 : b_conn = nullptr;
183 : 0 : }
184 : :
185 : 0 : bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler)
186 : : {
187 [ # # ]: 0 : if (!b_conn)
188 : 0 : return false;
189 : 0 : struct evbuffer *buf = bufferevent_get_output(b_conn);
190 [ # # ]: 0 : if (!buf)
191 : 0 : return false;
192 : 0 : evbuffer_add(buf, cmd.data(), cmd.size());
193 : 0 : evbuffer_add(buf, "\r\n", 2);
194 : 0 : reply_handlers.push_back(reply_handler);
195 : 0 : return true;
196 : 0 : }
197 : :
198 : : /****** General parsing utilities ********/
199 : :
200 : : /* Split reply line in the form 'AUTH METHODS=...' into a type
201 : : * 'AUTH' and arguments 'METHODS=...'.
202 : : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
203 : : * the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24).
204 : : */
205 : 0 : std::pair<std::string,std::string> SplitTorReplyLine(const std::string &s)
206 : : {
207 : 0 : size_t ptr=0;
208 : 0 : std::string type;
209 [ # # # # ]: 0 : while (ptr < s.size() && s[ptr] != ' ') {
210 [ # # ]: 0 : type.push_back(s[ptr]);
211 : 0 : ++ptr;
212 : : }
213 [ # # ]: 0 : if (ptr < s.size())
214 : 0 : ++ptr; // skip ' '
215 [ # # # # ]: 0 : return make_pair(type, s.substr(ptr));
216 : 0 : }
217 : :
218 : : /** Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'.
219 : : * Returns a map of keys to values, or an empty map if there was an error.
220 : : * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
221 : : * the server reply formats for PROTOCOLINFO (S3.21), AUTHCHALLENGE (S3.24),
222 : : * and ADD_ONION (S3.27). See also sections 2.1 and 2.3.
223 : : */
224 : 0 : std::map<std::string,std::string> ParseTorReplyMapping(const std::string &s)
225 : : {
226 : 0 : std::map<std::string,std::string> mapping;
227 : 0 : size_t ptr=0;
228 [ # # ]: 0 : while (ptr < s.size()) {
229 : 0 : std::string key, value;
230 [ # # # # : 0 : while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
# # ]
231 [ # # ]: 0 : key.push_back(s[ptr]);
232 : 0 : ++ptr;
233 : : }
234 [ # # ]: 0 : if (ptr == s.size()) // unexpected end of line
235 : 0 : return std::map<std::string,std::string>();
236 [ # # ]: 0 : if (s[ptr] == ' ') // The remaining string is an OptArguments
237 : 0 : break;
238 : 0 : ++ptr; // skip '='
239 [ # # # # ]: 0 : if (ptr < s.size() && s[ptr] == '"') { // Quoted string
240 : 0 : ++ptr; // skip opening '"'
241 : 0 : bool escape_next = false;
242 [ # # # # : 0 : while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
# # ]
243 : : // Repeated backslashes must be interpreted as pairs
244 [ # # ]: 0 : escape_next = (s[ptr] == '\\' && !escape_next);
245 [ # # ]: 0 : value.push_back(s[ptr]);
246 : 0 : ++ptr;
247 : : }
248 [ # # ]: 0 : if (ptr == s.size()) // unexpected end of line
249 : 0 : return std::map<std::string,std::string>();
250 : 0 : ++ptr; // skip closing '"'
251 : : /**
252 : : * Unescape value. Per https://spec.torproject.org/control-spec section 2.1.1:
253 : : *
254 : : * For future-proofing, controller implementors MAY use the following
255 : : * rules to be compatible with buggy Tor implementations and with
256 : : * future ones that implement the spec as intended:
257 : : *
258 : : * Read \n \t \r and \0 ... \377 as C escapes.
259 : : * Treat a backslash followed by any other character as that character.
260 : : */
261 : 0 : std::string escaped_value;
262 [ # # ]: 0 : for (size_t i = 0; i < value.size(); ++i) {
263 [ # # # # ]: 0 : if (value[i] == '\\') {
264 : : // This will always be valid, because if the QuotedString
265 : : // ended in an odd number of backslashes, then the parser
266 : : // would already have returned above, due to a missing
267 : : // terminating double-quote.
268 : 0 : ++i;
269 [ # # # # ]: 0 : if (value[i] == 'n') {
270 [ # # ]: 0 : escaped_value.push_back('\n');
271 [ # # # # ]: 0 : } else if (value[i] == 't') {
272 [ # # ]: 0 : escaped_value.push_back('\t');
273 [ # # # # ]: 0 : } else if (value[i] == 'r') {
274 [ # # ]: 0 : escaped_value.push_back('\r');
275 [ # # # # : 0 : } else if ('0' <= value[i] && value[i] <= '7') {
# # # # ]
276 : : size_t j;
277 : : // Octal escape sequences have a limit of three octal digits,
278 : : // but terminate at the first character that is not a valid
279 : : // octal digit if encountered sooner.
280 [ # # # # : 0 : for (j = 1; j < 3 && (i+j) < value.size() && '0' <= value[i+j] && value[i+j] <= '7'; ++j) {}
# # # # #
# # # ]
281 : : // Tor restricts first digit to 0-3 for three-digit octals.
282 : : // A leading digit of 4-7 would therefore be interpreted as
283 : : // a two-digit octal.
284 [ # # # # : 0 : if (j == 3 && value[i] > '3') {
# # ]
285 : 0 : j--;
286 : 0 : }
287 : 0 : const auto end{i + j};
288 : 0 : uint8_t val{0};
289 [ # # ]: 0 : while (i < end) {
290 : 0 : val *= 8;
291 [ # # ]: 0 : val += value[i++] - '0';
292 : : }
293 [ # # ]: 0 : escaped_value.push_back(char(val));
294 : : // Account for automatic incrementing at loop end
295 : 0 : --i;
296 : 0 : } else {
297 [ # # # # ]: 0 : escaped_value.push_back(value[i]);
298 : : }
299 : 0 : } else {
300 [ # # # # ]: 0 : escaped_value.push_back(value[i]);
301 : : }
302 : 0 : }
303 [ # # ]: 0 : value = escaped_value;
304 : 0 : } else { // Unquoted value. Note that values can contain '=' at will, just no spaces
305 [ # # # # ]: 0 : while (ptr < s.size() && s[ptr] != ' ') {
306 [ # # ]: 0 : value.push_back(s[ptr]);
307 : 0 : ++ptr;
308 : : }
309 : : }
310 [ # # # # ]: 0 : if (ptr < s.size() && s[ptr] == ' ')
311 : 0 : ++ptr; // skip ' ' after key=value
312 [ # # # # ]: 0 : mapping[key] = value;
313 [ # # # ]: 0 : }
314 : 0 : return mapping;
315 : 0 : }
316 : :
317 [ # # # # ]: 0 : TorController::TorController(struct event_base* _base, const std::string& tor_control_center, const CService& target):
318 : 0 : base(_base),
319 [ # # ]: 0 : m_tor_control_center(tor_control_center), conn(base), reconnect(true), reconnect_timeout(RECONNECT_TIMEOUT_START),
320 [ # # ]: 0 : m_target(target)
321 : : {
322 [ # # ]: 0 : reconnect_ev = event_new(base, -1, 0, reconnect_cb, this);
323 [ # # ]: 0 : if (!reconnect_ev)
324 [ # # # # : 0 : LogPrintf("tor: Failed to create event for reconnection: out of memory?\n");
# # ]
325 : : // Start connection attempts immediately
326 [ # # # # : 0 : if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
# # # # ]
327 [ # # # # ]: 0 : std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
328 [ # # # # : 0 : LogPrintf("tor: Initiating connection to Tor control port %s failed\n", m_tor_control_center);
# # ]
329 : 0 : }
330 : : // Read service private key if cached
331 [ # # # # ]: 0 : std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
332 [ # # ]: 0 : if (pkf.first) {
333 [ # # # # : 0 : LogPrint(BCLog::TOR, "Reading cached private key from %s\n", fs::PathToString(GetPrivateKeyFile()));
# # # # #
# # # #
# ]
334 [ # # ]: 0 : private_key = pkf.second;
335 : 0 : }
336 : 0 : }
337 : :
338 : 0 : TorController::~TorController()
339 : : {
340 [ # # ]: 0 : if (reconnect_ev) {
341 [ # # ]: 0 : event_free(reconnect_ev);
342 : 0 : reconnect_ev = nullptr;
343 : 0 : }
344 [ # # # # ]: 0 : if (service.IsValid()) {
345 [ # # ]: 0 : RemoveLocal(service);
346 : 0 : }
347 : 0 : }
348 : :
349 : 0 : void TorController::get_socks_cb(TorControlConnection& _conn, const TorControlReply& reply)
350 : : {
351 : : // NOTE: We can only get here if -onion is unset
352 : 0 : std::string socks_location;
353 [ # # ]: 0 : if (reply.code == 250) {
354 [ # # ]: 0 : for (const auto& line : reply.lines) {
355 [ # # # # ]: 0 : if (0 == line.compare(0, 20, "net/listeners/socks=")) {
356 [ # # ]: 0 : const std::string port_list_str = line.substr(20);
357 [ # # ]: 0 : std::vector<std::string> port_list = SplitString(port_list_str, ' ');
358 : :
359 [ # # ]: 0 : for (auto& portstr : port_list) {
360 [ # # ]: 0 : if (portstr.empty()) continue;
361 [ # # # # : 0 : if ((portstr[0] == '"' || portstr[0] == '\'') && portstr.size() >= 2 && (*portstr.rbegin() == portstr[0])) {
# # # # #
# # # #
# ]
362 [ # # ]: 0 : portstr = portstr.substr(1, portstr.size() - 2);
363 [ # # ]: 0 : if (portstr.empty()) continue;
364 : 0 : }
365 [ # # ]: 0 : socks_location = portstr;
366 [ # # # # ]: 0 : if (0 == portstr.compare(0, 10, "127.0.0.1:")) {
367 : : // Prefer localhost - ignore other ports
368 : 0 : break;
369 : : }
370 : : }
371 : 0 : }
372 : : }
373 [ # # ]: 0 : if (!socks_location.empty()) {
374 [ # # # # : 0 : LogPrint(BCLog::TOR, "Get SOCKS port command yielded %s\n", socks_location);
# # # # #
# ]
375 : 0 : } else {
376 [ # # # # : 0 : LogPrintf("tor: Get SOCKS port command returned nothing\n");
# # ]
377 : : }
378 [ # # ]: 0 : } else if (reply.code == 510) { // 510 Unrecognized command
379 [ # # # # : 0 : LogPrintf("tor: Get SOCKS port command failed with unrecognized command (You probably should upgrade Tor)\n");
# # ]
380 : 0 : } else {
381 [ # # # # : 0 : LogPrintf("tor: Get SOCKS port command failed; error code %d\n", reply.code);
# # ]
382 : : }
383 : :
384 [ # # ]: 0 : CService resolved;
385 [ # # # # ]: 0 : Assume(!resolved.IsValid());
386 [ # # ]: 0 : if (!socks_location.empty()) {
387 [ # # # # ]: 0 : resolved = LookupNumeric(socks_location, DEFAULT_TOR_SOCKS_PORT);
388 : 0 : }
389 [ # # # # ]: 0 : if (!resolved.IsValid()) {
390 : : // Fallback to old behaviour
391 [ # # # # : 0 : resolved = LookupNumeric("127.0.0.1", DEFAULT_TOR_SOCKS_PORT);
# # ]
392 : 0 : }
393 : :
394 [ # # # # ]: 0 : Assume(resolved.IsValid());
395 [ # # # # : 0 : LogPrint(BCLog::TOR, "Configuring onion proxy for %s\n", resolved.ToStringAddrPort());
# # # # #
# # # ]
396 [ # # ]: 0 : Proxy addrOnion = Proxy(resolved, true);
397 [ # # ]: 0 : SetProxy(NET_ONION, addrOnion);
398 : :
399 [ # # # # ]: 0 : const auto onlynets = gArgs.GetArgs("-onlynet");
400 : :
401 : 0 : const bool onion_allowed_by_onlynet{
402 [ # # # # : 0 : !gArgs.IsArgSet("-onlynet") ||
# # ]
403 [ # # ]: 0 : std::any_of(onlynets.begin(), onlynets.end(), [](const auto& n) {
404 : 0 : return ParseNetwork(n) == NET_ONION;
405 : : })};
406 : :
407 [ # # ]: 0 : if (onion_allowed_by_onlynet) {
408 : : // If NET_ONION is reachable, then the below is a noop.
409 : : //
410 : : // If NET_ONION is not reachable, then none of -proxy or -onion was given.
411 : : // Since we are here, then -torcontrol and -torpassword were given.
412 [ # # ]: 0 : SetReachable(NET_ONION, true);
413 : 0 : }
414 : 0 : }
415 : :
416 : 0 : void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlReply& reply)
417 : : {
418 [ # # ]: 0 : if (reply.code == 250) {
419 [ # # # # : 0 : LogPrint(BCLog::TOR, "ADD_ONION successful\n");
# # # # ]
420 [ # # ]: 0 : for (const std::string &s : reply.lines) {
421 : 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(s);
422 : 0 : std::map<std::string,std::string>::iterator i;
423 [ # # # # : 0 : if ((i = m.find("ServiceID")) != m.end())
# # ]
424 [ # # ]: 0 : service_id = i->second;
425 [ # # # # : 0 : if ((i = m.find("PrivateKey")) != m.end())
# # ]
426 [ # # ]: 0 : private_key = i->second;
427 : 0 : }
428 [ # # ]: 0 : if (service_id.empty()) {
429 [ # # # # : 0 : LogPrintf("tor: Error parsing ADD_ONION parameters:\n");
# # ]
430 [ # # ]: 0 : for (const std::string &s : reply.lines) {
431 [ # # # # : 0 : LogPrintf(" %s\n", SanitizeString(s));
# # # # ]
432 : : }
433 : 0 : return;
434 : : }
435 [ # # # # : 0 : service = LookupNumeric(std::string(service_id+".onion"), Params().GetDefaultPort());
# # # # ]
436 [ # # # # : 0 : LogPrintfCategory(BCLog::TOR, "Got service ID %s, advertising service %s\n", service_id, service.ToStringAddrPort());
# # # # ]
437 [ # # # # ]: 0 : if (WriteBinaryFile(GetPrivateKeyFile(), private_key)) {
438 [ # # # # : 0 : LogPrint(BCLog::TOR, "Cached service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
# # # # #
# # # ]
439 : 0 : } else {
440 [ # # # # : 0 : LogPrintf("tor: Error writing service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
# # # # #
# ]
441 : : }
442 : 0 : AddLocal(service, LOCAL_MANUAL);
443 : : // ... onion requested - keep connection open
444 [ # # ]: 0 : } else if (reply.code == 510) { // 510 Unrecognized command
445 [ # # # # : 0 : LogPrintf("tor: Add onion failed with unrecognized command (You probably need to upgrade Tor)\n");
# # ]
446 : 0 : } else {
447 [ # # # # : 0 : LogPrintf("tor: Add onion failed; error code %d\n", reply.code);
# # ]
448 : : }
449 : 0 : }
450 : :
451 : 0 : void TorController::auth_cb(TorControlConnection& _conn, const TorControlReply& reply)
452 : : {
453 [ # # ]: 0 : if (reply.code == 250) {
454 [ # # # # : 0 : LogPrint(BCLog::TOR, "Authentication successful\n");
# # # # ]
455 : :
456 : : // Now that we know Tor is running setup the proxy for onion addresses
457 : : // if -onion isn't set to something else.
458 [ # # # # : 0 : if (gArgs.GetArg("-onion", "") == "") {
# # # # #
# ]
459 [ # # # # : 0 : _conn.Command("GETINFO net/listeners/socks", std::bind(&TorController::get_socks_cb, this, std::placeholders::_1, std::placeholders::_2));
# # # # ]
460 : 0 : }
461 : :
462 : : // Finally - now create the service
463 [ # # ]: 0 : if (private_key.empty()) { // No private key, generate one
464 : 0 : private_key = "NEW:ED25519-V3"; // Explicitly request key type - see issue #9214
465 : 0 : }
466 : : // Request onion service, redirect port.
467 : : // Note that the 'virtual' port is always the default port to avoid decloaking nodes using other ports.
468 [ # # # # ]: 0 : _conn.Command(strprintf("ADD_ONION %s Port=%i,%s", private_key, Params().GetDefaultPort(), m_target.ToStringAddrPort()),
469 [ # # # # ]: 0 : std::bind(&TorController::add_onion_cb, this, std::placeholders::_1, std::placeholders::_2));
470 : 0 : } else {
471 [ # # # # : 0 : LogPrintf("tor: Authentication failed\n");
# # ]
472 : : }
473 : 0 : }
474 : :
475 : : /** Compute Tor SAFECOOKIE response.
476 : : *
477 : : * ServerHash is computed as:
478 : : * HMAC-SHA256("Tor safe cookie authentication server-to-controller hash",
479 : : * CookieString | ClientNonce | ServerNonce)
480 : : * (with the HMAC key as its first argument)
481 : : *
482 : : * After a controller sends a successful AUTHCHALLENGE command, the
483 : : * next command sent on the connection must be an AUTHENTICATE command,
484 : : * and the only authentication string which that AUTHENTICATE command
485 : : * will accept is:
486 : : *
487 : : * HMAC-SHA256("Tor safe cookie authentication controller-to-server hash",
488 : : * CookieString | ClientNonce | ServerNonce)
489 : : *
490 : : */
491 : 0 : static std::vector<uint8_t> ComputeResponse(const std::string &key, const std::vector<uint8_t> &cookie, const std::vector<uint8_t> &clientNonce, const std::vector<uint8_t> &serverNonce)
492 : : {
493 : 0 : CHMAC_SHA256 computeHash((const uint8_t*)key.data(), key.size());
494 [ # # ]: 0 : std::vector<uint8_t> computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0);
495 [ # # ]: 0 : computeHash.Write(cookie.data(), cookie.size());
496 [ # # ]: 0 : computeHash.Write(clientNonce.data(), clientNonce.size());
497 [ # # ]: 0 : computeHash.Write(serverNonce.data(), serverNonce.size());
498 [ # # ]: 0 : computeHash.Finalize(computedHash.data());
499 : 0 : return computedHash;
500 [ # # ]: 0 : }
501 : :
502 : 0 : void TorController::authchallenge_cb(TorControlConnection& _conn, const TorControlReply& reply)
503 : : {
504 [ # # ]: 0 : if (reply.code == 250) {
505 [ # # # # : 0 : LogPrint(BCLog::TOR, "SAFECOOKIE authentication challenge successful\n");
# # # # ]
506 : 0 : std::pair<std::string,std::string> l = SplitTorReplyLine(reply.lines[0]);
507 [ # # # # ]: 0 : if (l.first == "AUTHCHALLENGE") {
508 [ # # ]: 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
509 [ # # ]: 0 : if (m.empty()) {
510 [ # # # # : 0 : LogPrintf("tor: Error parsing AUTHCHALLENGE parameters: %s\n", SanitizeString(l.second));
# # # # ]
511 : 0 : return;
512 : : }
513 [ # # # # : 0 : std::vector<uint8_t> serverHash = ParseHex(m["SERVERHASH"]);
# # ]
514 [ # # # # : 0 : std::vector<uint8_t> serverNonce = ParseHex(m["SERVERNONCE"]);
# # ]
515 [ # # # # : 0 : LogPrint(BCLog::TOR, "AUTHCHALLENGE ServerHash %s ServerNonce %s\n", HexStr(serverHash), HexStr(serverNonce));
# # # # #
# # # # #
# # # # ]
516 [ # # ]: 0 : if (serverNonce.size() != 32) {
517 [ # # # # : 0 : LogPrintf("tor: ServerNonce is not 32 bytes, as required by spec\n");
# # ]
518 : 0 : return;
519 : : }
520 : :
521 [ # # ]: 0 : std::vector<uint8_t> computedServerHash = ComputeResponse(TOR_SAFE_SERVERKEY, cookie, clientNonce, serverNonce);
522 [ # # # # ]: 0 : if (computedServerHash != serverHash) {
523 [ # # # # : 0 : LogPrintf("tor: ServerHash %s does not match expected ServerHash %s\n", HexStr(serverHash), HexStr(computedServerHash));
# # # # #
# # # #
# ]
524 : 0 : return;
525 : : }
526 : :
527 [ # # ]: 0 : std::vector<uint8_t> computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, cookie, clientNonce, serverNonce);
528 [ # # # # : 0 : _conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
# # # # #
# # # ]
529 [ # # ]: 0 : } else {
530 [ # # # # : 0 : LogPrintf("tor: Invalid reply to AUTHCHALLENGE\n");
# # ]
531 : : }
532 [ # # # ]: 0 : } else {
533 [ # # # # : 0 : LogPrintf("tor: SAFECOOKIE authentication challenge failed\n");
# # ]
534 : : }
535 : 0 : }
536 : :
537 : 0 : void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorControlReply& reply)
538 : : {
539 [ # # ]: 0 : if (reply.code == 250) {
540 : 0 : std::set<std::string> methods;
541 : 0 : std::string cookiefile;
542 : : /*
543 : : * 250-AUTH METHODS=COOKIE,SAFECOOKIE COOKIEFILE="/home/x/.tor/control_auth_cookie"
544 : : * 250-AUTH METHODS=NULL
545 : : * 250-AUTH METHODS=HASHEDPASSWORD
546 : : */
547 [ # # ]: 0 : for (const std::string &s : reply.lines) {
548 [ # # ]: 0 : std::pair<std::string,std::string> l = SplitTorReplyLine(s);
549 [ # # # # ]: 0 : if (l.first == "AUTH") {
550 [ # # ]: 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
551 : 0 : std::map<std::string,std::string>::iterator i;
552 [ # # # # : 0 : if ((i = m.find("METHODS")) != m.end()) {
# # ]
553 [ # # ]: 0 : std::vector<std::string> m_vec = SplitString(i->second, ',');
554 [ # # ]: 0 : methods = std::set<std::string>(m_vec.begin(), m_vec.end());
555 : 0 : }
556 [ # # # # : 0 : if ((i = m.find("COOKIEFILE")) != m.end())
# # ]
557 [ # # ]: 0 : cookiefile = i->second;
558 [ # # # # ]: 0 : } else if (l.first == "VERSION") {
559 [ # # ]: 0 : std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
560 : 0 : std::map<std::string,std::string>::iterator i;
561 [ # # # # : 0 : if ((i = m.find("Tor")) != m.end()) {
# # ]
562 [ # # # # : 0 : LogPrint(BCLog::TOR, "Connected to Tor version %s\n", i->second);
# # # # #
# ]
563 : 0 : }
564 : 0 : }
565 : 0 : }
566 [ # # ]: 0 : for (const std::string &s : methods) {
567 [ # # # # : 0 : LogPrint(BCLog::TOR, "Supported authentication method: %s\n", s);
# # # # #
# ]
568 : : }
569 : : // Prefer NULL, otherwise SAFECOOKIE. If a password is provided, use HASHEDPASSWORD
570 : : /* Authentication:
571 : : * cookie: hex-encoded ~/.tor/control_auth_cookie
572 : : * password: "password"
573 : : */
574 [ # # # # : 0 : std::string torpassword = gArgs.GetArg("-torpassword", "");
# # ]
575 [ # # ]: 0 : if (!torpassword.empty()) {
576 [ # # # # : 0 : if (methods.count("HASHEDPASSWORD")) {
# # ]
577 [ # # # # : 0 : LogPrint(BCLog::TOR, "Using HASHEDPASSWORD authentication\n");
# # # # #
# ]
578 [ # # # # : 0 : ReplaceAll(torpassword, "\"", "\\\"");
# # ]
579 [ # # # # : 0 : _conn.Command("AUTHENTICATE \"" + torpassword + "\"", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
# # # # #
# ]
580 : 0 : } else {
581 [ # # # # : 0 : LogPrintf("tor: Password provided with -torpassword, but HASHEDPASSWORD authentication is not available\n");
# # ]
582 : : }
583 [ # # # # : 0 : } else if (methods.count("NULL")) {
# # ]
584 [ # # # # : 0 : LogPrint(BCLog::TOR, "Using NULL authentication\n");
# # # # #
# ]
585 [ # # # # : 0 : _conn.Command("AUTHENTICATE", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
# # # # ]
586 [ # # # # : 0 : } else if (methods.count("SAFECOOKIE")) {
# # ]
587 : : // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie
588 [ # # # # : 0 : LogPrint(BCLog::TOR, "Using SAFECOOKIE authentication, reading cookie authentication from %s\n", cookiefile);
# # # # #
# ]
589 [ # # # # ]: 0 : std::pair<bool,std::string> status_cookie = ReadBinaryFile(fs::PathFromString(cookiefile), TOR_COOKIE_SIZE);
590 [ # # # # ]: 0 : if (status_cookie.first && status_cookie.second.size() == TOR_COOKIE_SIZE) {
591 : : // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
592 [ # # ]: 0 : cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
593 [ # # ]: 0 : clientNonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
594 [ # # ]: 0 : GetRandBytes(clientNonce);
595 [ # # # # : 0 : _conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce), std::bind(&TorController::authchallenge_cb, this, std::placeholders::_1, std::placeholders::_2));
# # # # #
# # # ]
596 : 0 : } else {
597 [ # # ]: 0 : if (status_cookie.first) {
598 [ # # # # : 0 : LogPrintf("tor: Authentication cookie %s is not exactly %i bytes, as is required by the spec\n", cookiefile, TOR_COOKIE_SIZE);
# # ]
599 : 0 : } else {
600 [ # # # # : 0 : LogPrintf("tor: Authentication cookie %s could not be opened (check permissions)\n", cookiefile);
# # ]
601 : : }
602 : : }
603 [ # # # # : 0 : } else if (methods.count("HASHEDPASSWORD")) {
# # ]
604 [ # # # # : 0 : LogPrintf("tor: The only supported authentication mechanism left is password, but no password provided with -torpassword\n");
# # ]
605 : 0 : } else {
606 [ # # # # : 0 : LogPrintf("tor: No supported authentication method\n");
# # ]
607 : : }
608 : 0 : } else {
609 [ # # # # : 0 : LogPrintf("tor: Requesting protocol info failed\n");
# # ]
610 : : }
611 : 0 : }
612 : :
613 : 0 : void TorController::connected_cb(TorControlConnection& _conn)
614 : : {
615 : 0 : reconnect_timeout = RECONNECT_TIMEOUT_START;
616 : : // First send a PROTOCOLINFO command to figure out what authentication is expected
617 [ # # # # : 0 : if (!_conn.Command("PROTOCOLINFO 1", std::bind(&TorController::protocolinfo_cb, this, std::placeholders::_1, std::placeholders::_2)))
# # # # #
# ]
618 [ # # # # : 0 : LogPrintf("tor: Error sending initial protocolinfo command\n");
# # ]
619 : 0 : }
620 : :
621 : 0 : void TorController::disconnected_cb(TorControlConnection& _conn)
622 : : {
623 : : // Stop advertising service when disconnected
624 [ # # ]: 0 : if (service.IsValid())
625 : 0 : RemoveLocal(service);
626 : 0 : service = CService();
627 [ # # ]: 0 : if (!reconnect)
628 : 0 : return;
629 : :
630 [ # # # # : 0 : LogPrint(BCLog::TOR, "Not connected to Tor control port %s, trying to reconnect\n", m_tor_control_center);
# # # # ]
631 : :
632 : : // Single-shot timer for reconnect. Use exponential backoff.
633 : 0 : struct timeval time = MillisToTimeval(int64_t(reconnect_timeout * 1000.0));
634 [ # # ]: 0 : if (reconnect_ev)
635 : 0 : event_add(reconnect_ev, &time);
636 : 0 : reconnect_timeout *= RECONNECT_TIMEOUT_EXP;
637 : 0 : }
638 : :
639 : 0 : void TorController::Reconnect()
640 : : {
641 : : /* Try to reconnect and reestablish if we get booted - for example, Tor
642 : : * may be restarting.
643 : : */
644 [ # # # # ]: 0 : if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
645 [ # # # # ]: 0 : std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
646 [ # # # # : 0 : LogPrintf("tor: Re-initiating connection to Tor control port %s failed\n", m_tor_control_center);
# # ]
647 : 0 : }
648 : 0 : }
649 : :
650 : 0 : fs::path TorController::GetPrivateKeyFile()
651 : : {
652 [ # # ]: 0 : return gArgs.GetDataDirNet() / "onion_v3_private_key";
653 : 0 : }
654 : :
655 : 0 : void TorController::reconnect_cb(evutil_socket_t fd, short what, void *arg)
656 : : {
657 : 0 : TorController *self = static_cast<TorController*>(arg);
658 : 0 : self->Reconnect();
659 : 0 : }
660 : :
661 : : /****** Thread ********/
662 : : static struct event_base *gBase;
663 : 2 : static std::thread torControlThread;
664 : :
665 : 0 : static void TorControlThread(CService onion_service_target)
666 : : {
667 [ # # # # : 0 : TorController ctrl(gBase, gArgs.GetArg("-torcontrol", DEFAULT_TOR_CONTROL), onion_service_target);
# # ]
668 : :
669 [ # # ]: 0 : event_base_dispatch(gBase);
670 : 0 : }
671 : :
672 : 0 : void StartTorControl(CService onion_service_target)
673 : : {
674 [ # # ]: 0 : assert(!gBase);
675 : : #ifdef WIN32
676 : : evthread_use_windows_threads();
677 : : #else
678 : 0 : evthread_use_pthreads();
679 : : #endif
680 : 0 : gBase = event_base_new();
681 [ # # ]: 0 : if (!gBase) {
682 [ # # # # : 0 : LogPrintf("tor: Unable to create event_base\n");
# # ]
683 : 0 : return;
684 : : }
685 : :
686 [ # # ]: 0 : torControlThread = std::thread(&util::TraceThread, "torcontrol", [onion_service_target] {
687 [ # # ]: 0 : TorControlThread(onion_service_target);
688 : 0 : });
689 : 0 : }
690 : :
691 : 0 : void InterruptTorControl()
692 : : {
693 [ # # ]: 0 : if (gBase) {
694 [ # # # # : 0 : LogPrintf("tor: Thread interrupt\n");
# # ]
695 : 0 : event_base_once(gBase, -1, EV_TIMEOUT, [](evutil_socket_t, short, void*) {
696 : 0 : event_base_loopbreak(gBase);
697 : 0 : }, nullptr, nullptr);
698 : 0 : }
699 : 0 : }
700 : :
701 : 0 : void StopTorControl()
702 : : {
703 [ # # ]: 0 : if (gBase) {
704 : 0 : torControlThread.join();
705 : 0 : event_base_free(gBase);
706 : 0 : gBase = nullptr;
707 : 0 : }
708 : 0 : }
709 : :
710 : 0 : CService DefaultOnionServiceTarget()
711 : : {
712 : : struct in_addr onion_service_target;
713 : 0 : onion_service_target.s_addr = htonl(INADDR_LOOPBACK);
714 : 0 : return {onion_service_target, BaseParams().OnionServiceTargetPort()};
715 : : }
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