Load OpenSSL library and use QNetworkAccessManager makes application crash

Kalay_JY99

Hi.

I am working with Qt 5.2. I am using QNetworkAccessManager to make some posts to a web (without encryption). Now I have to verify a signature of message (That message has nothing to do with the post and QNetworkAccessManager, they are completly separated).

Both parts of code work fine separately, but when they come together the application crashes. If I add the OpenSSL to the application and I call a QNetworkAccessManager::post then it fails. The program pointer is in OPENSSL_sk_pop_free and it crashes after a QNetworkAccessManager::post call.

The code:

//#define OPENSSL

#include <QNetworkAccessManager>
#include <QNetworkRequest>
#include <openssl/bio.h>

#if defined(OPENSSL)
bool validateLicense()
{
    BIO* bio = BIO_new(BIO_s_mem());

    BIO_free(bio);

    return true;
}
#endif


int main() {
    QNetworkAccessManager* manager = new QNetworkAccessManager();

    QNetworkRequest request;
    request.setUrl(QUrl("http:\\192.168.0.1"));
    request.setHeader(QNetworkRequest::ContentTypeHeader, QVariant("application/json"));

    QString com("{\"hello world\"}");

    QByteArray data(com.toLocal8Bit());

    qDebug() << Q_FUNC_INFO << "data to POST" << com;

    manager->post(request, data);

#if defined(OPENSSL)
    validateLicense();
#endif
}

The .pro file:

QT += core network
QT -= gui

CONFIG += c++11

TARGET = console
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp

#
# libcrypto
#
LIBS += $$[OPENSSL_INSTALL_ROOT]/libcrypto.a

If I uncomment the #define OPENSSL the application crashes in line manager->post(request, data);.

How can I disable the OpenSSL in QNetworkAccessManager to avoid the application crash?

dheerendra

It may be issue with OpenSSL version compatibility. Qt may be looking for older version of OpenSSL library.

SGaist

Hi,

The first thing you should do is create a QCoreApplication object before trying to use QNetworkAccessManager.

What is currently happening is that you are trying to use the Qt network stack without its internals initialised.

Kalay_JY99

Hi.

@SGaist in the real application I have an QCoreApplication, this is just a minimal example.

SGaist

The problem with such an example is that it doesn't allow to replicate your problem correctly and triggers others that are not related to yours thus it's not possible to offer sensible help.