Ssl Server using QSslSocket in Qt - qt

Question

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:
#include "sslserver.h"
#include <QtNetwork/QTcpServer>
#include <QtNetwork/QTcpSocket>
#include <QFile>
#include <QtNetwork/QSslKey>
#include <QtNetwork/QSslConfiguration>
#include <QtNetwork/QSslError>
SslServer::SslServer(QObject *parent) : QTcpServer(parent)
{
server = new QTcpServer(this);
if(!server->listen(QHostAddress::Any, 9996))
{
qDebug() << "Server could not start";
}
else
{
qDebug() << "Server started!";
}
connect(server, SIGNAL(newConnection()), this, SLOT(newConnectionRecognized()));
}
void SslServer::showErrors()
{
this-> err = socket->sslErrors();
for(int i=0;i<err.size();i++)
qDebug() << err[i];
}
SslServer::~SslServer()
{
}
void SslServer::newConnectionRecognized()
{
incomingConnection(server->nextPendingConnection()->socketDescriptor());
}
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()));
// Read Key from file
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->isEncrypted())
emit socket->encrypted();
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";
}

Answer 1

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.