Transparent Proxy: why QTcpSocket receives no data when client sends HTTPS request - c++

Question

A proxy application which the client side redirect all connections to the server side application.
At the server side, QTcpServer::newConnection() signal is emitted and we connect QTcpSocket::readyRead() signal to our slot which receives the data from client and redirect the data to 3rd party application for handling HTTP/HTTPS requests. readyRead() signal emitted when client sends HTTP request but this does not happen with HTTPS requests.
Tried: Set QTcpServer::proxy() and QTcpSocket::proxy() to QNetworkProxy::NoProxy, use QSslSocket instead of QTcpSocket with ignoreSslErrors().
Code:
Client::Client(QObject *parent, QTcpSocket* clientCon)
: QObject(parent)
{
client = clientCon;
tunnel = new QSslSocket();
if (serverApp) // If application running as server
tunnel->connectToHost("127.0.0.1", 808); // Connect to CCProxy which handle the requests for us
else
{
tunnel->setProxy(QNetworkProxy::NoProxy);
tunnel->ignoreSslErrors();
tunnel->connectToHost(QHostAddress("serverip"), 9090); // Connect to the server side if running as client
}
tunnel->waitForConnected(5000); // 5 seconds timeout
if (tunnel->state() == tunnel->ConnectedState)
{
QObject::connect(client, SIGNAL(readyRead()), this, SLOT(ClientDataReceived()));
QObject::connect(tunnel, SIGNAL(readyRead()), this, SLOT(TunnelDataReceived()));
QObject::connect(client, SIGNAL(disconnected()), this, SLOT(ClientDisconnected()));
QObject::connect(tunnel, SIGNAL(disconnected()), this, SLOT(ClientDisconnected()));
}
}
Client::~Client()
{
}
bool Client::IsTunnelEstablished()
{
return tunnel->state() == tunnel->ConnectedState ? true : false;
}
QString Client::GetTunnelErrorString()
{
return tunnel->errorString();
}
void Client::ClientDataReceived()
{
QByteArray data = client->readAll();
qDebug() << "Client [" << client->peerAddress().toString().remove(" ") << ":" << client->peerPort() << "] Data Received: " << data.size();
qint64 wr = tunnel->write(data, data.size());
if (wr != data.size())
qDebug() << "QTcpSocket::write() failed!"; // Never happened
data.clear();
tunnel->flush();
}
void Client::TunnelDataReceived()
{
QByteArray data = tunnel->readAll();
qDebug() << "Client Tunnel [" << client->peerAddress().toString().remove(" ") << ":" << client->peerPort() << "] Data Received: " << data.size();
client->write(data);
data.clear();
client->flush();
}
void Client::ClientDisconnected()
{
/*if (tunnel->state() == tunnel->ConnectedState)
tunnel->close();*/
qDebug() << "[" << client->peerAddress().toString().remove(" ") << ":" << client->peerPort() << "] Disconnected";
QObject::disconnect(client, SIGNAL(readyRead()), this, SLOT(ClientDataReceived()));
QObject::disconnect(tunnel, SIGNAL(readyRead()), this, SLOT(TunnelDataReceived()));
QObject::disconnect(client, SIGNAL(disconnected()), this, SLOT(ClientDisconnected()));
QObject::disconnect(tunnel, SIGNAL(disconnected()), this, SLOT(ClientDisconnected()));
client->deleteLater();
tunnel->deleteLater();
delete this; // Self delete
}
Server Initialization:
void BaseProtocol::StartServer()
{
server = new QTcpServer();
server->setProxy(QNetworkProxy::NoProxy);
server->listen(QHostAddress("0.0.0.0"), serverApp ? 9090 : 5050); // 9090 for server, 5050 for client
qDebug() << QObject::connect(server, SIGNAL(newConnection()), this, SLOT(ClientConnecting()));
}
void BaseProtocol::ClientConnecting()
{
QTcpSocket *client = server->nextPendingConnection(); // Accept the connection
qDebug() << "Client Connected: " << client->peerAddress().toString() << ":" << client->peerPort();
Client* clientHandler = new Client(this, client);
if (!clientHandler->IsTunnelEstablished())
{
qDebug() << "Tunnel Connection Failed: " << clientHandler->GetTunnelErrorString() << "\n";
client->disconnect();
client->deleteLater();
delete clientHandler;
}
}
As you see the client and server application are the same but start with different ports. The reason why I use a client side application instead of connecting to the server as proxy directly is because I want to encrypt the data between client and server later. (same problem also exist when connecting directly to server side)
This is supposed to be a transparent proxy so there is no need for SSL/TLS at all.
"Internet Options" are used to set the proxy server to "127.0.0.1:5050" at the client side.