1 /*
2 This file is part of Telegram Desktop,
3 the official desktop application for the Telegram messaging service.
4
5 For license and copyright information please follow this link:
6 https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
7 */
8 #include "mtproto/special_config_request.h"
9
10 #include "mtproto/details/mtproto_rsa_public_key.h"
11 #include "mtproto/mtproto_dc_options.h"
12 #include "mtproto/mtproto_auth_key.h"
13 #include "base/unixtime.h"
14 #include "base/openssl_help.h"
15 #include "base/call_delayed.h"
16
17 #include <QtCore/QJsonDocument>
18 #include <QtCore/QJsonArray>
19 #include <QtCore/QJsonObject>
20
21 namespace MTP::details {
22 namespace {
23
24 constexpr auto kSendNextTimeout = crl::time(800);
25
26 constexpr auto kPublicKey = "\
27 -----BEGIN RSA PUBLIC KEY-----\n\
28 MIIBCgKCAQEAyr+18Rex2ohtVy8sroGPBwXD3DOoKCSpjDqYoXgCqB7ioln4eDCF\n\
29 fOBUlfXUEvM/fnKCpF46VkAftlb4VuPDeQSS/ZxZYEGqHaywlroVnXHIjgqoxiAd\n\
30 192xRGreuXIaUKmkwlM9JID9WS2jUsTpzQ91L8MEPLJ/4zrBwZua8W5fECwCCh2c\n\
31 9G5IzzBm+otMS/YKwmR1olzRCyEkyAEjXWqBI9Ftv5eG8m0VkBzOG655WIYdyV0H\n\
32 fDK/NWcvGqa0w/nriMD6mDjKOryamw0OP9QuYgMN0C9xMW9y8SmP4h92OAWodTYg\n\
33 Y1hZCxdv6cs5UnW9+PWvS+WIbkh+GaWYxwIDAQAB\n\
34 -----END RSA PUBLIC KEY-----\
35 "_cs;
36
37 const auto kRemoteProject = "peak-vista-421";
38 const auto kFireProject = "reserve-5a846";
39 const auto kConfigKey = "ipconfig";
40 const auto kConfigSubKey = "v3";
41 const auto kApiKey = "AIzaSyC2-kAkpDsroixRXw-sTw-Wfqo4NxjMwwM";
42 const auto kAppId = "1:560508485281:web:4ee13a6af4e84d49e67ae0";
43
ApiDomain(const QString & service)44 QString ApiDomain(const QString &service) {
45 return service + ".googleapis.com";
46 }
47
GenerateInstanceId()48 QString GenerateInstanceId() {
49 auto fid = bytes::array<17>();
50 bytes::set_random(fid);
51 fid[0] = (bytes::type(0xF0) & fid[0]) | bytes::type(0x07);
52 return QString::fromLatin1(
53 QByteArray::fromRawData(
54 reinterpret_cast<const char*>(fid.data()),
55 fid.size()
56 ).toBase64(QByteArray::Base64UrlEncoding).mid(0, 22));
57 }
58
InstanceId()59 QString InstanceId() {
60 static const auto result = GenerateInstanceId();
61 return result;
62 }
63
CheckPhoneByPrefixesRules(const QString & phone,const QString & rules)64 bool CheckPhoneByPrefixesRules(const QString &phone, const QString &rules) {
65 const auto check = QString(phone).replace(
66 QRegularExpression("[^0-9]"),
67 QString());
68 auto result = false;
69 for (const auto &prefix : rules.split(',')) {
70 if (prefix.isEmpty()) {
71 result = true;
72 } else if (prefix[0] == '+' && check.startsWith(prefix.mid(1))) {
73 result = true;
74 } else if (prefix[0] == '-' && check.startsWith(prefix.mid(1))) {
75 return false;
76 }
77 }
78 return result;
79 }
80
ConcatenateDnsTxtFields(const std::vector<DnsEntry> & response)81 QByteArray ConcatenateDnsTxtFields(const std::vector<DnsEntry> &response) {
82 auto entries = QMultiMap<int, QString>();
83 for (const auto &entry : response) {
84 entries.insert(INT_MAX - entry.data.size(), entry.data);
85 }
86 return QStringList(entries.values()).join(QString()).toLatin1();
87 }
88
ParseRemoteConfigResponse(const QByteArray & bytes)89 QByteArray ParseRemoteConfigResponse(const QByteArray &bytes) {
90 auto error = QJsonParseError{ 0, QJsonParseError::NoError };
91 const auto document = QJsonDocument::fromJson(bytes, &error);
92 if (error.error != QJsonParseError::NoError) {
93 LOG(("Config Error: Failed to parse fire response JSON, error: %1"
94 ).arg(error.errorString()));
95 return {};
96 } else if (!document.isObject()) {
97 LOG(("Config Error: Not an object received in fire response JSON."));
98 return {};
99 }
100 return document.object().value(
101 "entries"
102 ).toObject().value(
103 qsl("%1%2").arg(kConfigKey, kConfigSubKey)
104 ).toString().toLatin1();
105 }
106
ParseFireStoreResponse(const QByteArray & bytes)107 QByteArray ParseFireStoreResponse(const QByteArray &bytes) {
108 auto error = QJsonParseError{ 0, QJsonParseError::NoError };
109 const auto document = QJsonDocument::fromJson(bytes, &error);
110 if (error.error != QJsonParseError::NoError) {
111 LOG(("Config Error: Failed to parse fire response JSON, error: %1"
112 ).arg(error.errorString()));
113 return {};
114 } else if (!document.isObject()) {
115 LOG(("Config Error: Not an object received in fire response JSON."));
116 return {};
117 }
118 return document.object().value(
119 "fields"
120 ).toObject().value(
121 "data"
122 ).toObject().value(
123 "stringValue"
124 ).toString().toLatin1();
125 }
126
ParseRealtimeResponse(const QByteArray & bytes)127 QByteArray ParseRealtimeResponse(const QByteArray &bytes) {
128 if (bytes.size() < 2
129 || bytes[0] != '"'
130 || bytes[bytes.size() - 1] != '"') {
131 return QByteArray();
132 }
133 return bytes.mid(1, bytes.size() - 2);
134 }
135
ParseHttpDate(const QString & date)136 [[nodiscard]] QDateTime ParseHttpDate(const QString &date) {
137 // Wed, 10 Jul 2019 14:33:38 GMT
138 static const auto expression = QRegularExpression(
139 R"(\w\w\w, (\d\d) (\w\w\w) (\d\d\d\d) (\d\d):(\d\d):(\d\d) GMT)");
140 const auto match = expression.match(date);
141 if (!match.hasMatch()) {
142 return QDateTime();
143 }
144
145 const auto number = [&](int index) {
146 return match.capturedView(index).toInt();
147 };
148 const auto day = number(1);
149 const auto month = [&] {
150 static const auto months = {
151 "Jan",
152 "Feb",
153 "Mar",
154 "Apr",
155 "May",
156 "Jun",
157 "Jul",
158 "Aug",
159 "Sep",
160 "Oct",
161 "Nov",
162 "Dec"
163 };
164 const auto captured = match.capturedView(2);
165 for (auto i = begin(months); i != end(months); ++i) {
166 if (captured == QString(*i)) {
167 return 1 + int(i - begin(months));
168 }
169 }
170 return 0;
171 }();
172 const auto year = number(3);
173 const auto hour = number(4);
174 const auto minute = number(5);
175 const auto second = number(6);
176 return QDateTime(
177 QDate(year, month, day),
178 QTime(hour, minute, second),
179 Qt::UTC);
180 }
181
182 } // namespace
183
SpecialConfigRequest(Fn<void (DcId dcId,const std::string & ip,int port,bytes::const_span secret)> callback,Fn<void ()> timeDoneCallback,const QString & domainString,const QString & phone)184 SpecialConfigRequest::SpecialConfigRequest(
185 Fn<void(
186 DcId dcId,
187 const std::string &ip,
188 int port,
189 bytes::const_span secret)> callback,
190 Fn<void()> timeDoneCallback,
191 const QString &domainString,
192 const QString &phone)
193 : _callback(std::move(callback))
194 , _timeDoneCallback(std::move(timeDoneCallback))
195 , _domainString(domainString)
196 , _phone(phone) {
197 Expects((_callback == nullptr) != (_timeDoneCallback == nullptr));
198
199 _manager.setProxy(QNetworkProxy::NoProxy);
200
201 auto domains = DnsDomains();
202 const auto domainsCount = domains.size();
203
204 std::random_device rd;
205 ranges::shuffle(domains, std::mt19937(rd()));
206 const auto takeDomain = [&] {
207 const auto result = domains.back();
208 domains.pop_back();
209 return result;
210 };
211 const auto shuffle = [&](int from, int till) {
212 Expects(till > from);
213
214 ranges::shuffle(
215 begin(_attempts) + from,
216 begin(_attempts) + till,
217 std::mt19937(rd()));
218 };
219
220 _attempts = {};
221 _attempts.push_back({ Type::Google, "dns.google.com" });
222 _attempts.push_back({ Type::Google, takeDomain(), "dns" });
223 _attempts.push_back({ Type::Mozilla, "mozilla.cloudflare-dns.com" });
224 _attempts.push_back({ Type::RemoteConfig, "firebaseremoteconfig" });
225 while (!domains.empty()) {
226 _attempts.push_back({ Type::Google, takeDomain(), "dns" });
227 }
228 if (!_timeDoneCallback) {
229 _attempts.push_back({ Type::Realtime, "firebaseio.com" });
230 _attempts.push_back({ Type::FireStore, "firestore" });
231 for (const auto &domain : DnsDomains()) {
232 _attempts.push_back({ Type::FireStore, domain, "firestore" });
233 }
234 }
235
236 shuffle(0, 2);
237 shuffle(2, 4);
238 if (!_timeDoneCallback) {
239 shuffle(
240 _attempts.size() - (2 + domainsCount),
241 _attempts.size() - domainsCount);
242 shuffle(_attempts.size() - domainsCount, _attempts.size());
243 }
244 ranges::reverse(_attempts); // We go from last to first.
245
246 sendNextRequest();
247 }
248
SpecialConfigRequest(Fn<void (DcId dcId,const std::string & ip,int port,bytes::const_span secret)> callback,const QString & domainString,const QString & phone)249 SpecialConfigRequest::SpecialConfigRequest(
250 Fn<void(
251 DcId dcId,
252 const std::string &ip,
253 int port,
254 bytes::const_span secret)> callback,
255 const QString &domainString,
256 const QString &phone)
257 : SpecialConfigRequest(std::move(callback), nullptr, domainString, phone) {
258 }
259
SpecialConfigRequest(Fn<void ()> timeDoneCallback,const QString & domainString)260 SpecialConfigRequest::SpecialConfigRequest(
261 Fn<void()> timeDoneCallback,
262 const QString &domainString)
263 : SpecialConfigRequest(
264 nullptr,
265 std::move(timeDoneCallback),
266 domainString,
267 QString()) {
268 }
269
sendNextRequest()270 void SpecialConfigRequest::sendNextRequest() {
271 Expects(!_attempts.empty());
272
273 const auto attempt = _attempts.back();
274 _attempts.pop_back();
275 if (!_attempts.empty()) {
276 base::call_delayed(kSendNextTimeout, this, [=] {
277 sendNextRequest();
278 });
279 }
280 performRequest(attempt);
281 }
282
performRequest(const Attempt & attempt)283 void SpecialConfigRequest::performRequest(const Attempt &attempt) {
284 const auto type = attempt.type;
285 auto url = QUrl();
286 url.setScheme(qsl("https"));
287 auto request = QNetworkRequest();
288 auto payload = QByteArray();
289 switch (type) {
290 case Type::Mozilla: {
291 url.setHost(attempt.data);
292 url.setPath(qsl("/dns-query"));
293 url.setQuery(qsl("name=%1&type=16&random_padding=%2").arg(
294 _domainString,
295 GenerateDnsRandomPadding()));
296 request.setRawHeader("accept", "application/dns-json");
297 } break;
298 case Type::Google: {
299 url.setHost(attempt.data);
300 url.setPath(qsl("/resolve"));
301 url.setQuery(qsl("name=%1&type=ANY&random_padding=%2").arg(
302 _domainString,
303 GenerateDnsRandomPadding()));
304 if (!attempt.host.isEmpty()) {
305 const auto host = attempt.host + ".google.com";
306 request.setRawHeader("Host", host.toLatin1());
307 }
308 } break;
309 case Type::RemoteConfig: {
310 url.setHost(ApiDomain(attempt.data));
311 url.setPath(qsl("/v1/projects/%1/namespaces/firebase:fetch"
312 ).arg(kRemoteProject));
313 url.setQuery(qsl("key=%1").arg(kApiKey));
314 payload = qsl("{\"app_id\":\"%1\",\"app_instance_id\":\"%2\"}").arg(
315 kAppId,
316 InstanceId()).toLatin1();
317 request.setRawHeader("Content-Type", "application/json");
318 } break;
319 case Type::Realtime: {
320 url.setHost(kFireProject + qsl(".%1").arg(attempt.data));
321 url.setPath(qsl("/%1%2.json").arg(kConfigKey, kConfigSubKey));
322 } break;
323 case Type::FireStore: {
324 url.setHost(attempt.host.isEmpty()
325 ? ApiDomain(attempt.data)
326 : attempt.data);
327 url.setPath(qsl("/v1/projects/%1/databases/(default)/documents/%2/%3"
328 ).arg(
329 kFireProject,
330 kConfigKey,
331 kConfigSubKey));
332 if (!attempt.host.isEmpty()) {
333 const auto host = ApiDomain(attempt.host);
334 request.setRawHeader("Host", host.toLatin1());
335 }
336 } break;
337 default: Unexpected("Type in SpecialConfigRequest::performRequest.");
338 }
339 request.setUrl(url);
340 request.setRawHeader("User-Agent", DnsUserAgent());
341 const auto reply = _requests.emplace_back(payload.isEmpty()
342 ? _manager.get(request)
343 : _manager.post(request, payload)
344 ).reply;
345 connect(reply, &QNetworkReply::finished, this, [=] {
346 requestFinished(type, reply);
347 });
348 }
349
handleHeaderUnixtime(not_null<QNetworkReply * > reply)350 void SpecialConfigRequest::handleHeaderUnixtime(
351 not_null<QNetworkReply*> reply) {
352 if (reply->error() != QNetworkReply::NoError) {
353 return;
354 }
355 const auto date = QString::fromLatin1([&] {
356 for (const auto &pair : reply->rawHeaderPairs()) {
357 if (pair.first == "Date") {
358 return pair.second;
359 }
360 }
361 return QByteArray();
362 }());
363 if (date.isEmpty()) {
364 LOG(("Config Error: No 'Date' header received."));
365 return;
366 }
367 const auto parsed = ParseHttpDate(date);
368 if (!parsed.isValid()) {
369 LOG(("Config Error: Bad 'Date' header received: %1").arg(date));
370 return;
371 }
372 base::unixtime::http_update(parsed.toSecsSinceEpoch());
373 if (_timeDoneCallback) {
374 _timeDoneCallback();
375 }
376 }
377
requestFinished(Type type,not_null<QNetworkReply * > reply)378 void SpecialConfigRequest::requestFinished(
379 Type type,
380 not_null<QNetworkReply*> reply) {
381 handleHeaderUnixtime(reply);
382 const auto result = finalizeRequest(reply);
383 if (!_callback || result.isEmpty()) {
384 return;
385 }
386
387 switch (type) {
388 case Type::Mozilla:
389 case Type::Google: {
390 constexpr auto kTypeRestriction = 16; // TXT
391 handleResponse(ConcatenateDnsTxtFields(
392 ParseDnsResponse(result, kTypeRestriction)));
393 } break;
394 case Type::RemoteConfig: {
395 handleResponse(ParseRemoteConfigResponse(result));
396 } break;
397 case Type::Realtime: {
398 handleResponse(ParseRealtimeResponse(result));
399 } break;
400 case Type::FireStore: {
401 handleResponse(ParseFireStoreResponse(result));
402 } break;
403 default: Unexpected("Type in SpecialConfigRequest::requestFinished.");
404 }
405 }
406
finalizeRequest(not_null<QNetworkReply * > reply)407 QByteArray SpecialConfigRequest::finalizeRequest(
408 not_null<QNetworkReply*> reply) {
409 if (reply->error() != QNetworkReply::NoError) {
410 DEBUG_LOG(("Config Error: Failed to get response, error: %2 (%3)"
411 ).arg(reply->errorString()
412 ).arg(reply->error()));
413 }
414 const auto result = reply->readAll();
415 const auto from = ranges::remove(
416 _requests,
417 reply,
418 [](const ServiceWebRequest &request) { return request.reply; });
419 _requests.erase(from, end(_requests));
420 return result;
421 }
422
decryptSimpleConfig(const QByteArray & bytes)423 bool SpecialConfigRequest::decryptSimpleConfig(const QByteArray &bytes) {
424 auto cleanBytes = bytes;
425 auto removeFrom = std::remove_if(cleanBytes.begin(), cleanBytes.end(), [](char ch) {
426 auto isGoodBase64 = (ch == '+') || (ch == '=') || (ch == '/')
427 || (ch >= 'a' && ch <= 'z')
428 || (ch >= 'A' && ch <= 'Z')
429 || (ch >= '0' && ch <= '9');
430 return !isGoodBase64;
431 });
432 if (removeFrom != cleanBytes.end()) {
433 cleanBytes.remove(removeFrom - cleanBytes.begin(), cleanBytes.end() - removeFrom);
434 }
435
436 constexpr auto kGoodSizeBase64 = 344;
437 if (cleanBytes.size() != kGoodSizeBase64) {
438 LOG(("Config Error: Bad data size %1 required %2").arg(cleanBytes.size()).arg(kGoodSizeBase64));
439 return false;
440 }
441 constexpr auto kGoodSizeData = 256;
442 auto decodedBytes = QByteArray::fromBase64(cleanBytes, QByteArray::Base64Encoding);
443 if (decodedBytes.size() != kGoodSizeData) {
444 LOG(("Config Error: Bad data size %1 required %2").arg(decodedBytes.size()).arg(kGoodSizeData));
445 return false;
446 }
447
448 auto publicKey = details::RSAPublicKey(bytes::make_span(kPublicKey));
449 auto decrypted = publicKey.decrypt(bytes::make_span(decodedBytes));
450 auto decryptedBytes = gsl::make_span(decrypted);
451
452 auto aesEncryptedBytes = decryptedBytes.subspan(CTRState::KeySize);
453 auto aesivec = bytes::make_vector(decryptedBytes.subspan(CTRState::KeySize - CTRState::IvecSize, CTRState::IvecSize));
454 AES_KEY aeskey;
455 AES_set_decrypt_key(reinterpret_cast<const unsigned char*>(decryptedBytes.data()), CTRState::KeySize * CHAR_BIT, &aeskey);
456 AES_cbc_encrypt(reinterpret_cast<const unsigned char*>(aesEncryptedBytes.data()), reinterpret_cast<unsigned char*>(aesEncryptedBytes.data()), aesEncryptedBytes.size(), &aeskey, reinterpret_cast<unsigned char*>(aesivec.data()), AES_DECRYPT);
457
458 constexpr auto kDigestSize = 16;
459 auto dataSize = aesEncryptedBytes.size() - kDigestSize;
460 auto data = aesEncryptedBytes.subspan(0, dataSize);
461 auto hash = openssl::Sha256(data);
462 if (bytes::compare(gsl::make_span(hash).subspan(0, kDigestSize), aesEncryptedBytes.subspan(dataSize)) != 0) {
463 LOG(("Config Error: Bad digest."));
464 return false;
465 }
466
467 mtpBuffer buffer;
468 buffer.resize(data.size() / sizeof(mtpPrime));
469 bytes::copy(bytes::make_span(buffer), data);
470 auto from = &*buffer.cbegin();
471 auto end = from + buffer.size();
472 auto realLength = *from++;
473 if (realLength <= 0 || realLength > dataSize || (realLength & 0x03)) {
474 LOG(("Config Error: Bad length %1.").arg(realLength));
475 return false;
476 }
477
478 if (!_simpleConfig.read(from, end)) {
479 LOG(("Config Error: Could not read configSimple."));
480 return false;
481 }
482 if ((end - from) * sizeof(mtpPrime) != (dataSize - realLength)) {
483 LOG(("Config Error: Bad read length %1, should be %2.").arg((end - from) * sizeof(mtpPrime)).arg(dataSize - realLength));
484 return false;
485 }
486 return true;
487 }
488
handleResponse(const QByteArray & bytes)489 void SpecialConfigRequest::handleResponse(const QByteArray &bytes) {
490 if (!decryptSimpleConfig(bytes)) {
491 return;
492 }
493 Assert(_simpleConfig.type() == mtpc_help_configSimple);
494 const auto &config = _simpleConfig.c_help_configSimple();
495 const auto now = base::unixtime::http_now();
496 if (now > config.vexpires().v) {
497 LOG(("Config Error: "
498 "Bad date frame for simple config: %1-%2, our time is %3."
499 ).arg(config.vdate().v
500 ).arg(config.vexpires().v
501 ).arg(now));
502 return;
503 }
504 if (config.vrules().v.empty()) {
505 LOG(("Config Error: Empty simple config received."));
506 return;
507 }
508 for (const auto &rule : config.vrules().v) {
509 Assert(rule.type() == mtpc_accessPointRule);
510 const auto &data = rule.c_accessPointRule();
511 const auto phoneRules = qs(data.vphone_prefix_rules());
512 if (!CheckPhoneByPrefixesRules(_phone, phoneRules)) {
513 continue;
514 }
515
516 const auto dcId = data.vdc_id().v;
517 for (const auto &address : data.vips().v) {
518 const auto parseIp = [](const MTPint &ipv4) {
519 const auto ip = *reinterpret_cast<const uint32*>(&ipv4.v);
520 return qsl("%1.%2.%3.%4"
521 ).arg((ip >> 24) & 0xFF
522 ).arg((ip >> 16) & 0xFF
523 ).arg((ip >> 8) & 0xFF
524 ).arg(ip & 0xFF).toStdString();
525 };
526 switch (address.type()) {
527 case mtpc_ipPort: {
528 const auto &fields = address.c_ipPort();
529 const auto ip = parseIp(fields.vipv4());
530 if (!ip.empty()) {
531 _callback(dcId, ip, fields.vport().v, {});
532 }
533 } break;
534 case mtpc_ipPortSecret: {
535 const auto &fields = address.c_ipPortSecret();
536 const auto ip = parseIp(fields.vipv4());
537 if (!ip.empty()) {
538 _callback(
539 dcId,
540 ip,
541 fields.vport().v,
542 bytes::make_span(fields.vsecret().v));
543 }
544 } break;
545 default: Unexpected("Type in simpleConfig ips.");
546 }
547 }
548 }
549 _callback(0, std::string(), 0, {});
550 }
551
552 } // namespace MTP::details
553