Problem with creating ssl server using QSslSocket

[Eehsanmgh]

I have implemented a ssl server using QSslSocket and run it correctly. But I have some problem with it that I couldn't solve them immediately.
I thought that just connecting readyRead() signal to a slot for reading buffer is sufficient to do that but I have recognized that the readyRead() does not emit at all in this situation and I must also use waitForReadyRead() function in my code. But the problem is using this function cause blocking read the buffer. Actually I want to know how I can read buffer when data has arrived without blocking.

Bellow is my implemented ssl server:

void SslServer::incomingConnection(qintptr socketDescriptor)
{

    socket = new QSslSocket(this);
    socket->setProtocol(QSsl::SslV3);

    connect(socket, SIGNAL(sslErrors(QList<QSslError>)), this, SLOT(showErrors()));
    connect(socket, SIGNAL(encrypted()), this, SLOT(ready()));
    connect(socket, SIGNAL(readyRead()), this, SLOT(readChannel()));
    QByteArray key;
    QFile KeyFile("server.key");
    if(KeyFile.open(QIODevice::ReadOnly))
    {
        key = KeyFile.readAll();
        KeyFile.close();
    }
    else
    {
        qDebug() << KeyFile.errorString();
    }

    QSslKey sslKey(key, QSsl::Rsa);
    socket->setPrivateKey(sslKey);


    // Load server ssl certificate from file
    QByteArray cert;
    QFile CertFile("server.csr");
    if(CertFile.open(QIODevice::ReadOnly))
    {
        cert = CertFile.readAll();
        CertFile.close();
    }
    else
    {
        qDebug() << CertFile.errorString();
    }

    QSslCertificate sslCert(cert);
    socket->setLocalCertificate(sslCert);

    QSslConfiguration cfg = socket->sslConfiguration();
    cfg.caCertificates();

    if (!socket->setSocketDescriptor(socketDescriptor))ee
    {
        qDebug() << ("! Couldn't set socket descriptor");
        delete socket;
        return;
    }

    socket->startServerEncryption();

    if(!socket->waitForEncrypted(3000)) {
        qDebug("Wait for encrypted!!!!");
        return;
    }
    while (true) {
        socket->waitForReadyRead();
    }
}

void SslServer::readChannel()
{
    QByteArray qstrbytes = socket->readLine();
    qDebug() << qstrbytes;
}

void SslServer::ready()
{
    qDebug() << "Encrypted";
}

[cybercatalyst]

Hey there, you might take a look into QtWebServer. This is a plug and play ssl server library that you can use for your own apps. It already has SSL support available and is very easy to use:

https://github.com/cybercatalyst/qtwebserver

It has only Qt as the only dependency, so no other libs required. Here are a bunch of examples:

https://github.com/cybercatalyst/qtwebserver-examples

This example shows you how to set up an SSL server for delivering websites over HTTPS:
https://github.com/cybercatalyst/qtwebserver-examples/tree/master/https

[Eehsanmgh]

Thank you my friend. But using QSslSocket is critical for the project I have involved. Actually we must use QSslSocket for this project.

[cybercatalyst]

Yes, I am using QSslSocket in QtWebServer.

[Eehsanmgh]

@cybercatalyst Actually I intended to implement an encryption based secure socket library for using by our Qt users such as QSslSocket. The protocol has implemented and now I want to know how QSslSocket works. After that I want to mimic QSslSocket for using our encryption protocol.

[t3685]

@Eehsanmgh

Stupid question, but do you have an event loop running?

[Eehsanmgh]

@t3685 How I should do that? I guess this is for multi-threading

[t3685]

@Eehsanmgh

The event loop is not needed for multi-threading, but is needed for signal and slots. You should check the documentation regarding this, but usually it involves creating a Q(Core)Application object in the main function and call the run function.

[Eehsanmgh]

I have found the problem when I implement another client/server but this time with QTcpSocket. I dont know exactly why but I guess the problem is because of using socketDescriptor for creating a QSslSocket. When I created client and server with QTcpSocket they works perfectly without any event loop and only by connecting readyRead() signal to an slot. After that in order to testing some situation I have create QTcpSocket using socketDescriptor. Then I found the problem is from creating socket using socketDescriptor because this time the readyRead() signal doesn't work as before.

[t3685]

@Eehsanmgh

Are you sure there are no SSL errors?

[Eehsanmgh]

@t3685 Yes I'm sure.