tdesktop/Telegram/SourceFiles/mtproto/connection_tcp.cpp

484 lines
14 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.
For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#include "mtproto/connection_tcp.h"
#include "base/bytes.h"
#include "base/openssl_help.h"
#include "base/qthelp_url.h"
extern "C" {
#include <openssl/aes.h>
} // extern "C"
namespace MTP {
namespace internal {
namespace {
constexpr auto kPacketSizeMax = 64 * 1024 * 1024U;
constexpr auto kFullConnectionTimeout = 8 * TimeMs(1000);
uint32 CountTcpPacketSize(const char *packet) { // must have at least 4 bytes readable
uint32 result = (packet[0] > 0) ? packet[0] : 0;
if (result == 0x7f) {
const uchar *bytes = reinterpret_cast<const uchar*>(packet);
result = (((uint32(bytes[3]) << 8) | uint32(bytes[2])) << 8) | uint32(bytes[1]);
return (result << 2) + 4;
}
return (result << 2) + 1;
}
using ErrorSignal = void(QTcpSocket::*)(QAbstractSocket::SocketError);
const auto QTcpSocket_error = ErrorSignal(&QAbstractSocket::error);
} // namespace
TcpConnection::TcpConnection(QThread *thread, const ProxyData &proxy)
: AbstractConnection(thread, proxy)
, _currentPosition(reinterpret_cast<char*>(_shortBuffer))
, _checkNonce(rand_value<MTPint128>()) {
_socket.moveToThread(thread);
_socket.setProxy(ToNetworkProxy(proxy));
connect(
&_socket,
&QTcpSocket::connected,
this,
&TcpConnection::socketConnected);
connect(
&_socket,
&QTcpSocket::disconnected,
this,
&TcpConnection::socketDisconnected);
connect(
&_socket,
&QTcpSocket::readyRead,
this,
&TcpConnection::socketRead);
connect(
&_socket,
QTcpSocket_error,
this,
&TcpConnection::socketError);
}
ConnectionPointer TcpConnection::clone(const ProxyData &proxy) {
return ConnectionPointer::New<TcpConnection>(thread(), proxy);
}
void TcpConnection::socketRead() {
if (_socket.state() != QAbstractSocket::ConnectedState) {
LOG(("MTP error: "
"socket not connected in socketRead(), state: %1"
).arg(_socket.state()));
emit error(kErrorCodeOther);
return;
}
do {
uint32 toRead = _packetLeft
? _packetLeft
: (_readingToShort
? (kShortBufferSize * sizeof(mtpPrime) - _packetRead)
: 4);
if (_readingToShort) {
if (_currentPosition + toRead > ((char*)_shortBuffer) + kShortBufferSize * sizeof(mtpPrime)) {
_longBuffer.resize(((_packetRead + toRead) >> 2) + 1);
memcpy(&_longBuffer[0], _shortBuffer, _packetRead);
_currentPosition = ((char*)&_longBuffer[0]) + _packetRead;
_readingToShort = false;
}
} else {
if (_longBuffer.size() * sizeof(mtpPrime) < _packetRead + toRead) {
_longBuffer.resize(((_packetRead + toRead) >> 2) + 1);
_currentPosition = ((char*)&_longBuffer[0]) + _packetRead;
}
}
int32 bytes = (int32)_socket.read(_currentPosition, toRead);
if (bytes > 0) {
aesCtrEncrypt(_currentPosition, bytes, _receiveKey, &_receiveState);
TCP_LOG(("TCP Info: read %1 bytes").arg(bytes));
_packetRead += bytes;
_currentPosition += bytes;
if (_packetLeft) {
_packetLeft -= bytes;
if (!_packetLeft) {
socketPacket(_currentPosition - _packetRead, _packetRead);
_currentPosition = (char*)_shortBuffer;
_packetRead = _packetLeft = 0;
_readingToShort = true;
_longBuffer.clear();
} else {
TCP_LOG(("TCP Info: not enough %1 for packet! read %2").arg(_packetLeft).arg(_packetRead));
emit receivedSome();
}
} else {
bool move = false;
while (_packetRead >= 4) {
uint32 packetSize = CountTcpPacketSize(_currentPosition - _packetRead);
if (packetSize < 5 || packetSize > kPacketSizeMax) {
LOG(("TCP Error: packet size = %1").arg(packetSize));
emit error(kErrorCodeOther);
return;
}
if (_packetRead >= packetSize) {
socketPacket(_currentPosition - _packetRead, packetSize);
_packetRead -= packetSize;
_packetLeft = 0;
move = true;
} else {
_packetLeft = packetSize - _packetRead;
TCP_LOG(("TCP Info: not enough %1 for packet! size %2 read %3").arg(_packetLeft).arg(packetSize).arg(_packetRead));
emit receivedSome();
break;
}
}
if (move) {
if (!_packetRead) {
_currentPosition = (char*)_shortBuffer;
_readingToShort = true;
_longBuffer.clear();
} else if (!_readingToShort && _packetRead < kShortBufferSize * sizeof(mtpPrime)) {
memcpy(_shortBuffer, _currentPosition - _packetRead, _packetRead);
_currentPosition = (char*)_shortBuffer + _packetRead;
_readingToShort = true;
_longBuffer.clear();
}
}
}
} else if (bytes < 0) {
LOG(("TCP Error: socket read return -1"));
emit error(kErrorCodeOther);
return;
} else {
TCP_LOG(("TCP Info: no bytes read, but bytes available was true..."));
break;
}
} while (_socket.state() == QAbstractSocket::ConnectedState && _socket.bytesAvailable());
}
mtpBuffer TcpConnection::handleResponse(const char *packet, uint32 length) {
if (length < 5 || length > kPacketSizeMax) {
LOG(("TCP Error: bad packet size %1").arg(length));
return mtpBuffer(1, -500);
}
int32 size = packet[0], len = length - 1;
if (size == 0x7f) {
const uchar *bytes = reinterpret_cast<const uchar*>(packet);
size = (((uint32(bytes[3]) << 8) | uint32(bytes[2])) << 8) | uint32(bytes[1]);
len -= 3;
}
if (size * int32(sizeof(mtpPrime)) != len) {
LOG(("TCP Error: bad packet header"));
TCP_LOG(("TCP Error: bad packet header, packet: %1").arg(Logs::mb(packet, length).str()));
return mtpBuffer(1, -500);
}
const mtpPrime *packetdata = reinterpret_cast<const mtpPrime*>(packet + (length - len));
TCP_LOG(("TCP Info: packet received, size = %1").arg(size * sizeof(mtpPrime)));
if (size == 1) {
LOG(("TCP Error: "
"error packet received, endpoint: '%1:%2', "
"protocolDcId: %3, secret_len: %4, code = %5"
).arg(_address.isEmpty() ? ("proxy_" + _proxy.host) : _address
).arg(_address.isEmpty() ? _proxy.port : _port
).arg(_protocolDcId
).arg(_protocolSecret.size()
).arg(*packetdata));
return mtpBuffer(1, *packetdata);
}
mtpBuffer data(size);
memcpy(data.data(), packetdata, size * sizeof(mtpPrime));
return data;
}
void TcpConnection::handleError(QAbstractSocket::SocketError e, QTcpSocket &socket) {
switch (e) {
case QAbstractSocket::ConnectionRefusedError:
LOG(("TCP Error: socket connection refused - %1").arg(socket.errorString()));
break;
case QAbstractSocket::RemoteHostClosedError:
TCP_LOG(("TCP Info: remote host closed socket connection - %1").arg(socket.errorString()));
break;
case QAbstractSocket::HostNotFoundError:
LOG(("TCP Error: host not found - %1").arg(socket.errorString()));
break;
case QAbstractSocket::SocketTimeoutError:
LOG(("TCP Error: socket timeout - %1").arg(socket.errorString()));
break;
case QAbstractSocket::NetworkError:
LOG(("TCP Error: network - %1").arg(socket.errorString()));
break;
case QAbstractSocket::ProxyAuthenticationRequiredError:
case QAbstractSocket::ProxyConnectionRefusedError:
case QAbstractSocket::ProxyConnectionClosedError:
case QAbstractSocket::ProxyConnectionTimeoutError:
case QAbstractSocket::ProxyNotFoundError:
case QAbstractSocket::ProxyProtocolError:
LOG(("TCP Error: proxy (%1) - %2").arg(e).arg(socket.errorString()));
break;
default:
LOG(("TCP Error: other (%1) - %2").arg(e).arg(socket.errorString()));
break;
}
TCP_LOG(("TCP Error %1, restarting! - %2").arg(e).arg(socket.errorString()));
}
void TcpConnection::socketConnected() {
Expects(_status == Status::Waiting);
auto buffer = preparePQFake(_checkNonce);
DEBUG_LOG(("TCP Info: "
"dc:%1 - Sending fake req_pq to '%2'"
).arg(_protocolDcId
).arg(_address + ':' + QString::number(_port)));
_pingTime = getms();
sendData(buffer);
}
void TcpConnection::socketDisconnected() {
if (_status == Status::Waiting || _status == Status::Ready) {
emit disconnected();
}
}
void TcpConnection::sendData(mtpBuffer &buffer) {
if (_status == Status::Finished) return;
if (buffer.size() < 3) {
LOG(("TCP Error: writing bad packet, len = %1").arg(buffer.size() * sizeof(mtpPrime)));
TCP_LOG(("TCP Error: bad packet %1").arg(Logs::mb(&buffer[0], buffer.size() * sizeof(mtpPrime)).str()));
emit error(kErrorCodeOther);
return;
}
sendBuffer(buffer);
}
void TcpConnection::writeConnectionStart() {
// prepare random part
auto nonceBytes = bytes::vector(64);
const auto nonce = bytes::make_span(nonceBytes);
const auto zero = reinterpret_cast<uchar*>(nonce.data());
const auto first = reinterpret_cast<uint32*>(nonce.data());
const auto second = first + 1;
const auto reserved01 = 0x000000EFU;
const auto reserved11 = 0x44414548U;
const auto reserved12 = 0x54534F50U;
const auto reserved13 = 0x20544547U;
const auto reserved14 = 0xEEEEEEEEU;
const auto reserved21 = 0x00000000U;
do {
bytes::set_random(nonce);
} while (*zero == reserved01
|| *first == reserved11
|| *first == reserved12
|| *first == reserved13
|| *first == reserved14
|| *second == reserved21);
const auto prepareKey = [&](bytes::span key, bytes::const_span from) {
if (_protocolSecret.size() == 16) {
const auto payload = bytes::concatenate(from, _protocolSecret);
bytes::copy(key, openssl::Sha256(payload));
} else if (_protocolSecret.empty()) {
bytes::copy(key, from);
} else {
bytes::set_with_const(key, gsl::byte{});
}
};
// prepare encryption key/iv
prepareKey(
bytes::make_span(_sendKey),
nonce.subspan(8, CTRState::KeySize));
bytes::copy(
bytes::make_span(_sendState.ivec),
nonce.subspan(8 + CTRState::KeySize, CTRState::IvecSize));
// prepare decryption key/iv
auto reversedBytes = bytes::vector(48);
const auto reversed = bytes::make_span(reversedBytes);
bytes::copy(reversed, nonce.subspan(8, reversed.size()));
std::reverse(reversed.begin(), reversed.end());
prepareKey(
bytes::make_span(_receiveKey),
reversed.subspan(0, CTRState::KeySize));
bytes::copy(
bytes::make_span(_receiveState.ivec),
reversed.subspan(CTRState::KeySize, CTRState::IvecSize));
// write protocol and dc ids
const auto protocol = reinterpret_cast<uint32*>(nonce.data() + 56);
*protocol = 0xEFEFEFEFU;
const auto dcId = reinterpret_cast<int16*>(nonce.data() + 60);
*dcId = _protocolDcId;
_socket.write(reinterpret_cast<const char*>(nonce.data()), 56);
aesCtrEncrypt(nonce.data(), 64, _sendKey, &_sendState);
_socket.write(reinterpret_cast<const char*>(nonce.subspan(56).data()), 8);
}
void TcpConnection::sendBuffer(mtpBuffer &buffer) {
if (!_packetIndex++) {
writeConnectionStart();
}
uint32 size = buffer.size() - 3, len = size * 4;
char *data = reinterpret_cast<char*>(&buffer[0]);
if (size < 0x7f) {
data[7] = char(size);
TCP_LOG(("TCP Info: write %1 packet %2").arg(_packetIndex).arg(len + 1));
aesCtrEncrypt(data + 7, len + 1, _sendKey, &_sendState);
_socket.write(data + 7, len + 1);
} else {
data[4] = 0x7f;
reinterpret_cast<uchar*>(data)[5] = uchar(size & 0xFF);
reinterpret_cast<uchar*>(data)[6] = uchar((size >> 8) & 0xFF);
reinterpret_cast<uchar*>(data)[7] = uchar((size >> 16) & 0xFF);
TCP_LOG(("TCP Info: write %1 packet %2").arg(_packetIndex).arg(len + 4));
aesCtrEncrypt(data + 4, len + 4, _sendKey, &_sendState);
_socket.write(data + 4, len + 4);
}
}
void TcpConnection::disconnectFromServer() {
if (_status == Status::Finished) return;
_status = Status::Finished;
disconnect(&_socket, &QTcpSocket::connected, nullptr, nullptr);
disconnect(&_socket, &QTcpSocket::disconnected, nullptr, nullptr);
disconnect(&_socket, &QTcpSocket::readyRead, nullptr, nullptr);
disconnect(&_socket, QTcpSocket_error, nullptr, nullptr);
_socket.close();
}
void TcpConnection::connectToServer(
const QString &address,
int port,
const bytes::vector &protocolSecret,
int16 protocolDcId) {
Expects(_address.isEmpty());
Expects(_port == 0);
Expects(_protocolSecret.empty());
Expects(_protocolDcId == 0);
if (_proxy.type == ProxyData::Type::Mtproto) {
_address = _proxy.host;
_port = _proxy.port;
_protocolSecret = ProtocolSecretFromPassword(_proxy.password);
DEBUG_LOG(("TCP Info: "
"dc:%1 - Connecting to proxy '%2'"
).arg(protocolDcId
).arg(_address + ':' + QString::number(_port)));
} else {
_address = address;
_port = port;
_protocolSecret = protocolSecret;
DEBUG_LOG(("TCP Info: "
"dc:%1 - Connecting to '%2'"
).arg(protocolDcId
).arg(_address + ':' + QString::number(_port)));
}
_protocolDcId = protocolDcId;
_socket.connectToHost(_address, _port);
}
TimeMs TcpConnection::pingTime() const {
return isConnected() ? _pingTime : TimeMs(0);
}
TimeMs TcpConnection::fullConnectTimeout() const {
return kFullConnectionTimeout;
}
void TcpConnection::socketPacket(const char *packet, uint32 length) {
if (_status == Status::Finished) return;
const auto data = handleResponse(packet, length);
if (data.size() == 1) {
emit error(data[0]);
} else if (_status == Status::Ready) {
_receivedQueue.push_back(data);
emit receivedData();
} else if (_status == Status::Waiting) {
try {
const auto res_pq = readPQFakeReply(data);
const auto &data = res_pq.c_resPQ();
if (data.vnonce == _checkNonce) {
DEBUG_LOG(("Connection Info: Valid pq response by TCP."));
_status = Status::Ready;
disconnect(
&_socket,
&QTcpSocket::connected,
nullptr,
nullptr);
_pingTime = (getms() - _pingTime);
emit connected();
}
} catch (Exception &e) {
DEBUG_LOG(("Connection Error: exception in parsing TCP fake pq-responce, %1").arg(e.what()));
emit error(kErrorCodeOther);
}
}
}
bool TcpConnection::isConnected() const {
return (_status == Status::Ready);
}
int32 TcpConnection::debugState() const {
return _socket.state();
}
QString TcpConnection::transport() const {
if (!isConnected()) {
return QString();
}
auto result = qsl("TCP");
if (qthelp::is_ipv6(_address)) {
result += qsl("/IPv6");
}
return result;
}
QString TcpConnection::tag() const {
auto result = qsl("TCP");
if (qthelp::is_ipv6(_address)) {
result += qsl("/IPv6");
} else {
result += qsl("/IPv4");
}
return result;
}
void TcpConnection::socketError(QAbstractSocket::SocketError e) {
if (_status == Status::Finished) return;
handleError(e, _socket);
emit error(kErrorCodeOther);
}
} // namespace internal
} // namespace MTP