239 lines
		
	
	
	
		
			8.9 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			239 lines
		
	
	
	
		
			8.9 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
 | 
						|
This file is part of Telegram Desktop,
 | 
						|
the official desktop version of Telegram messaging app, see https://telegram.org
 | 
						|
 | 
						|
Telegram Desktop is free software: you can redistribute it and/or modify
 | 
						|
it under the terms of the GNU General Public License as published by
 | 
						|
the Free Software Foundation, either version 3 of the License, or
 | 
						|
(at your option) any later version.
 | 
						|
 | 
						|
It is distributed in the hope that it will be useful,
 | 
						|
but WITHOUT ANY WARRANTY; without even the implied warranty of
 | 
						|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 | 
						|
GNU General Public License for more details.
 | 
						|
 | 
						|
In addition, as a special exception, the copyright holders give permission
 | 
						|
to link the code of portions of this program with the OpenSSL library.
 | 
						|
 | 
						|
Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
 | 
						|
Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 | 
						|
*/
 | 
						|
#include "mtproto/special_config_request.h"
 | 
						|
 | 
						|
#include "mtproto/rsa_public_key.h"
 | 
						|
#include "mtproto/dc_options.h"
 | 
						|
#include "mtproto/auth_key.h"
 | 
						|
#include "base/openssl_help.h"
 | 
						|
#include <openssl/aes.h>
 | 
						|
 | 
						|
namespace MTP {
 | 
						|
namespace {
 | 
						|
 | 
						|
constexpr auto kPublicKey = str_const("\
 | 
						|
-----BEGIN RSA PUBLIC KEY-----\n\
 | 
						|
MIIBCgKCAQEAyr+18Rex2ohtVy8sroGPBwXD3DOoKCSpjDqYoXgCqB7ioln4eDCF\n\
 | 
						|
fOBUlfXUEvM/fnKCpF46VkAftlb4VuPDeQSS/ZxZYEGqHaywlroVnXHIjgqoxiAd\n\
 | 
						|
192xRGreuXIaUKmkwlM9JID9WS2jUsTpzQ91L8MEPLJ/4zrBwZua8W5fECwCCh2c\n\
 | 
						|
9G5IzzBm+otMS/YKwmR1olzRCyEkyAEjXWqBI9Ftv5eG8m0VkBzOG655WIYdyV0H\n\
 | 
						|
fDK/NWcvGqa0w/nriMD6mDjKOryamw0OP9QuYgMN0C9xMW9y8SmP4h92OAWodTYg\n\
 | 
						|
Y1hZCxdv6cs5UnW9+PWvS+WIbkh+GaWYxwIDAQAB\n\
 | 
						|
-----END RSA PUBLIC KEY-----\
 | 
						|
");
 | 
						|
 | 
						|
} // namespace
 | 
						|
 | 
						|
SpecialConfigRequest::SpecialConfigRequest(base::lambda<void(DcId dcId, const std::string &ip, int port)> callback) : _callback(std::move(callback)) {
 | 
						|
	App::setProxySettings(_manager);
 | 
						|
 | 
						|
	performAppRequest();
 | 
						|
	performDnsRequest();
 | 
						|
}
 | 
						|
 | 
						|
void SpecialConfigRequest::performAppRequest() {
 | 
						|
	auto appUrl = QUrl();
 | 
						|
	appUrl.setScheme(qsl("https"));
 | 
						|
	appUrl.setHost(qsl("google.com"));
 | 
						|
	if (cTestMode()) {
 | 
						|
		appUrl.setPath(qsl("/test/"));
 | 
						|
	}
 | 
						|
	auto appRequest = QNetworkRequest(appUrl);
 | 
						|
	appRequest.setRawHeader("Host", "dns-telegram.appspot.com");
 | 
						|
	_appReply.reset(_manager.get(appRequest));
 | 
						|
	connect(_appReply.get(), &QNetworkReply::finished, this, [this] { appFinished(); });
 | 
						|
}
 | 
						|
 | 
						|
void SpecialConfigRequest::performDnsRequest() {
 | 
						|
	auto dnsUrl = QUrl();
 | 
						|
	dnsUrl.setScheme(qsl("https"));
 | 
						|
	dnsUrl.setHost(qsl("google.com"));
 | 
						|
	dnsUrl.setPath(qsl("/resolve"));
 | 
						|
	dnsUrl.setQuery(qsl("name=%1.stel.com&type=16").arg(cTestMode() ? qsl("tap") : qsl("ap")));
 | 
						|
	auto dnsRequest = QNetworkRequest(QUrl(dnsUrl));
 | 
						|
	dnsRequest.setRawHeader("Host", "dns.google.com");
 | 
						|
	_dnsReply.reset(_manager.get(dnsRequest));
 | 
						|
	connect(_dnsReply.get(), &QNetworkReply::finished, this, [this] { dnsFinished(); });
 | 
						|
}
 | 
						|
 | 
						|
void SpecialConfigRequest::appFinished() {
 | 
						|
	if (!_appReply) {
 | 
						|
		return;
 | 
						|
	}
 | 
						|
	auto result = _appReply->readAll();
 | 
						|
	_appReply.release()->deleteLater();
 | 
						|
	handleResponse(result);
 | 
						|
}
 | 
						|
 | 
						|
void SpecialConfigRequest::dnsFinished() {
 | 
						|
	if (!_dnsReply) {
 | 
						|
		return;
 | 
						|
	}
 | 
						|
	if (_dnsReply->error() != QNetworkReply::NoError) {
 | 
						|
		LOG(("Config Error: Failed to get dns response JSON, error: %1 (%2)").arg(_dnsReply->errorString()).arg(_dnsReply->error()));
 | 
						|
	}
 | 
						|
	auto result = _dnsReply->readAll();
 | 
						|
	_dnsReply.release()->deleteLater();
 | 
						|
 | 
						|
	// Read and store to "entries" map all the data bytes from this response:
 | 
						|
	// { .., "Answer": [ { .., "data": "bytes1", .. }, { .., "data": "bytes2", .. } ], .. }
 | 
						|
	auto entries = QMap<int, QString>();
 | 
						|
	auto error = QJsonParseError { 0, QJsonParseError::NoError };
 | 
						|
	auto document = QJsonDocument::fromJson(result, &error);
 | 
						|
	if (error.error != QJsonParseError::NoError) {
 | 
						|
		LOG(("Config Error: Failed to parse dns response JSON, error: %1").arg(error.errorString()));
 | 
						|
	} else if (!document.isObject()) {
 | 
						|
		LOG(("Config Error: Not an object received in dns response JSON."));
 | 
						|
	} else {
 | 
						|
		auto response = document.object();
 | 
						|
		auto answerIt = response.find(qsl("Answer"));
 | 
						|
		if (answerIt == response.constEnd()) {
 | 
						|
			LOG(("Config Error: Could not find Answer in dns response JSON."));
 | 
						|
		} else if (!(*answerIt).isArray()) {
 | 
						|
			LOG(("Config Error: Not an array received in Answer in dns response JSON."));
 | 
						|
		} else {
 | 
						|
			for (auto elem : (*answerIt).toArray()) {
 | 
						|
				if (!elem.isObject()) {
 | 
						|
					LOG(("Config Error: Not an object found in Answer array in dns response JSON."));
 | 
						|
				} else {
 | 
						|
					auto object = elem.toObject();
 | 
						|
					auto dataIt = object.find(qsl("data"));
 | 
						|
					if (dataIt == object.constEnd()) {
 | 
						|
						LOG(("Config Error: Could not find data in Answer array entry in dns response JSON."));
 | 
						|
					} else if (!(*dataIt).isString()) {
 | 
						|
						LOG(("Config Error: Not a string data found in Answer array entry in dns response JSON."));
 | 
						|
					} else {
 | 
						|
						auto data = (*dataIt).toString();
 | 
						|
						entries.insertMulti(INT_MAX - data.size(), data);
 | 
						|
					}
 | 
						|
				}
 | 
						|
			}
 | 
						|
		}
 | 
						|
	}
 | 
						|
	auto text = QStringList(entries.values()).join(QString());
 | 
						|
	handleResponse(text.toLatin1());
 | 
						|
}
 | 
						|
 | 
						|
bool SpecialConfigRequest::decryptSimpleConfig(const QByteArray &bytes) {
 | 
						|
	auto cleanBytes = bytes;
 | 
						|
	auto removeFrom = std::remove_if(cleanBytes.begin(), cleanBytes.end(), [](char ch) {
 | 
						|
		auto isGoodBase64 = (ch == '+') || (ch == '=') || (ch == '/')
 | 
						|
			|| (ch >= 'a' && ch <= 'z')
 | 
						|
			|| (ch >= 'A' && ch <= 'Z')
 | 
						|
			|| (ch >= '0' && ch <= '9');
 | 
						|
		return !isGoodBase64;
 | 
						|
	});
 | 
						|
	if (removeFrom != cleanBytes.end()) {
 | 
						|
		cleanBytes.remove(removeFrom - cleanBytes.begin(), cleanBytes.end() - removeFrom);
 | 
						|
	}
 | 
						|
 | 
						|
	constexpr auto kGoodSizeBase64 = 344;
 | 
						|
	if (cleanBytes.size() != kGoodSizeBase64) {
 | 
						|
		LOG(("Config Error: Bad data size %1 required %2").arg(cleanBytes.size()).arg(kGoodSizeBase64));
 | 
						|
		return false;
 | 
						|
	}
 | 
						|
	constexpr auto kGoodSizeData = 256;
 | 
						|
	auto decodedBytes = QByteArray::fromBase64(cleanBytes, QByteArray::Base64Encoding);
 | 
						|
	if (decodedBytes.size() != kGoodSizeData) {
 | 
						|
		LOG(("Config Error: Bad data size %1 required %2").arg(decodedBytes.size()).arg(kGoodSizeData));
 | 
						|
		return false;
 | 
						|
	}
 | 
						|
 | 
						|
	auto publicKey = internal::RSAPublicKey(gsl::as_bytes(gsl::make_span(kPublicKey.c_str(), kPublicKey.size())));
 | 
						|
	auto decrypted = publicKey.decrypt(gsl::as_bytes(gsl::make_span(decodedBytes)));
 | 
						|
	auto decryptedBytes = gsl::make_span(decrypted);
 | 
						|
 | 
						|
	constexpr auto kAesKeySize = CTRState::KeySize;
 | 
						|
	constexpr auto kAesIvecSize = CTRState::IvecSize;
 | 
						|
	auto aesEncryptedBytes = decryptedBytes.subspan(kAesKeySize);
 | 
						|
	base::byte_array<kAesIvecSize> aesivec;
 | 
						|
	base::copy_bytes(aesivec, decryptedBytes.subspan(CTRState::KeySize - CTRState::IvecSize, CTRState::IvecSize));
 | 
						|
	AES_KEY aeskey;
 | 
						|
	AES_set_decrypt_key(reinterpret_cast<const unsigned char*>(decryptedBytes.data()), kAesKeySize * CHAR_BIT, &aeskey);
 | 
						|
	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);
 | 
						|
 | 
						|
	constexpr auto kDigestSize = 16;
 | 
						|
	auto dataSize = aesEncryptedBytes.size() - kDigestSize;
 | 
						|
	auto data = aesEncryptedBytes.subspan(0, dataSize);
 | 
						|
	auto hash = openssl::Sha256(data);
 | 
						|
	if (base::compare_bytes(gsl::make_span(hash).subspan(0, kDigestSize), aesEncryptedBytes.subspan(dataSize)) != 0) {
 | 
						|
		LOG(("Config Error: Bad digest."));
 | 
						|
		return false;
 | 
						|
	}
 | 
						|
 | 
						|
	mtpBuffer buffer;
 | 
						|
	buffer.resize(data.size() / sizeof(mtpPrime));
 | 
						|
	base::copy_bytes(gsl::as_writeable_bytes(gsl::make_span(buffer)), data);
 | 
						|
	auto from = &*buffer.cbegin();
 | 
						|
	auto end = from + buffer.size();
 | 
						|
	auto realLength = *from++;
 | 
						|
	if (realLength <= 0 || realLength > dataSize || (realLength & 0x03)) {
 | 
						|
		LOG(("Config Error: Bad length %1.").arg(realLength));
 | 
						|
		return false;
 | 
						|
	}
 | 
						|
 | 
						|
	try {
 | 
						|
		_simpleConfig.read(from, end);
 | 
						|
	} catch (...) {
 | 
						|
		LOG(("Config Error: Could not read configSimple."));
 | 
						|
		return false;
 | 
						|
	}
 | 
						|
	if ((end - from) * sizeof(mtpPrime) != (dataSize - realLength)) {
 | 
						|
		LOG(("Config Error: Bad read length %1, should be %2.").arg((end - from) * sizeof(mtpPrime)).arg(dataSize - realLength));
 | 
						|
		return false;
 | 
						|
	}
 | 
						|
	return true;
 | 
						|
}
 | 
						|
 | 
						|
void SpecialConfigRequest::handleResponse(const QByteArray &bytes) {
 | 
						|
	if (!decryptSimpleConfig(bytes)) {
 | 
						|
		return;
 | 
						|
	}
 | 
						|
	Assert(_simpleConfig.type() == mtpc_help_configSimple);
 | 
						|
	auto &config = _simpleConfig.c_help_configSimple();
 | 
						|
	auto now = unixtime();
 | 
						|
	if (now < config.vdate.v || now > config.vexpires.v) {
 | 
						|
		LOG(("Config Error: Bad date frame for simple config: %1-%2, our time is %3.").arg(config.vdate.v).arg(config.vexpires.v).arg(now));
 | 
						|
		return;
 | 
						|
	}
 | 
						|
	if (config.vip_port_list.v.empty()) {
 | 
						|
		LOG(("Config Error: Empty simple config received."));
 | 
						|
		return;
 | 
						|
	}
 | 
						|
	for (auto &entry : config.vip_port_list.v) {
 | 
						|
		Assert(entry.type() == mtpc_ipPort);
 | 
						|
		auto &ipPort = entry.c_ipPort();
 | 
						|
		auto ip = *reinterpret_cast<const uint32*>(&ipPort.vipv4.v);
 | 
						|
		auto ipString = qsl("%1.%2.%3.%4").arg((ip >> 24) & 0xFF).arg((ip >> 16) & 0xFF).arg((ip >> 8) & 0xFF).arg(ip & 0xFF);
 | 
						|
		_callback(config.vdc_id.v, ipString.toStdString(), ipPort.vport.v);
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
SpecialConfigRequest::~SpecialConfigRequest() {
 | 
						|
	if (_appReply) {
 | 
						|
		_appReply->abort();
 | 
						|
	}
 | 
						|
	if (_dnsReply) {
 | 
						|
		_dnsReply->abort();
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
} // namespace MTP
 |