Important: Please read the Qt Code of Conduct -

OpenSSL 1.1.1c Toolkit in clean Windows 10

  • I have the last version Qt 5.13.0 (online installer) with OpenSSL 1.1.1c Toolkit . I created simple QtWidget application with one https request (MinGW 64bit). I added the path D:\Qt\Tools\OpenSSL\Win_x64\bin to the system variable PATH.

    QT       += core gui network
    greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
    TARGET = untitled1
    TEMPLATE = app
    CONFIG += c++11
    SOURCES += \
            main.cpp \
    HEADERS += \
    FORMS += \
    # Default rules for deployment.
    qnx: target.path = /tmp/$${TARGET}/bin
    else: unix:!android: target.path = /opt/$${TARGET}/bin
    !isEmpty(target.path): INSTALLS += target
    #include "mainwindow.h"
    #include "ui_mainwindow.h"
    MainWindow::MainWindow(QWidget *parent) :
      ui(new Ui::MainWindow)
      delete ui;
    void MainWindow::on_pushButton_clicked()
      QNetworkAccessManager *manager;
      QNetworkRequest request;
      QSslConfiguration sSlConfig;
      request.setAttribute(QNetworkRequest::FollowRedirectsAttribute, true);
      manager = new QNetworkAccessManager(this);
      connect(manager, SIGNAL(finished(QNetworkReply*)),
              this, SLOT(replyFinished(QNetworkReply*)));
    void MainWindow::replyFinished(QNetworkReply* reply) {
      if (reply->error() == QNetworkReply::NoError) {
        QByteArray bytes = reply->readAll();
        QString html = QString::fromUtf8(, bytes.size());
        int statusCode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
        QString url = reply->url().toString();
        ui->textEdit->insertPlainText("statusCode = " + QString::number(statusCode) + "\n");
        ui->textEdit->insertPlainText("url = " + url + "\n");
        ui->textEdit->insertPlainText("html = " + html + "\n");
      } else {
        qDebug() << reply->errorString();

    And application works.

    Then I want to run the EXE file in a clean Windows 10. For running an application I use these dll:

    • libgcc_s_seh-1.dll
    • libstdc++-6.dll
    • libwinpthread-1.dll
    • Qt5Core.dll
    • Qt5Gui.dll
    • Qt5Network.dll
    • Qt5Widgets.dll
    • platforms
    • └───qwindows.dll

    Apllication runs, but https request does not work. I understand that I need to add dll files for OpenSSL. But https request do not work again after adding dll files from D:\Qt\Tools\OpenSSL\Win_x64\bin:

    • libcrypto-1_1-x64.dll
    • libssl-1_1-x64.dll

    But when I use vesrions of these dll files from (Win64 OpenSSL v1.1.1c) my application works in clean Windows 10 (after installing vc_redist.x64.exe).

    What could be the problem with the files libcrypto-1_1-x64.dll and libssl-1_1-x64.dll in the folder D:\Qt\Tools\OpenSSL\Win_x64\bin?

  • Lifetime Qt Champion


    Likely because they are not built with the same compiler. Qt Creator is built with Visual Studio while you are using MinGW.

  • @SGaist No. Files from compiled under Visual Studio and require vc_redist.x64.exe. But they work with my apllication compiled under MinGW 64bit.

    And now I compiled my test application under MSVC2017 64bit. And situation is the same. Files from work with the application, but files from D:\Qt\Tools\OpenSSL\Win_x64\bin do not work in a clean Windows 10.

  • Lifetime Qt Champion

    Right ! These are C libraries !

    Check these .dlls with Dependency Walker, you might find so what differs between these sets.

    By the way, can you check which version of Qt was used to build Qt Creator ?

  • @Harrix Did you resolve this? I have the same issue. If I install Qt/Felgo on the clean pc, the app can work. I think I'm missing a dll when deploying the app.

Log in to reply