OpenSSL in Qt5 on Windows

Question

I'm trying to link openssl with qt5.12 but the result differs when running executable from qt and from command line. I use QSslSocket::supportsSsl(), QSslSocket::sslLibraryVersionString() and QSslSocket::sslLibraryBuildVersionString() to observe the results. When running exe from qt i get the following output respectively true OpenSSL 1.1.1d 10 Sep 2019 OpenSSL 1.1.1k 25 Mar 2021 and for command line false "" OpenSSL 1.1.1k 25 Mar 2021 . The exe is compiled with msvc 2017 64 bit. What could be the problem and where does qt get that library from?

Answer 1

Using listdlls tool i managed to find the name and location of openssl DLLs. They're libssl-1_1-x64.dll and libcrypto-1_1-x64.dll and located in %QT_INSTALL_PATH%/Tools/QtCreator/bin . Copying those DLLs to the build folder of the project solved the issue.

QtCreator used build environment which is apparently the default environment and can be found in Projects -> Run . It sets a number of environment variables, and in my case exactly, it updated the PATH variable adding the path of QtCreator bin folder.

Answer 2

Qt doesn't ship SSL libraries by default, you need to install them manually, to be sure that you have compatible SSL libraries Install OpenSSL XXX Toolkit from Qt Maintenance Tool then in <Qt directory>/Tools/OpenSSL you will find your OpenSSL packages with binaries.

In order to fully ship Windows Qt application to the end-users, please study https://doc.qt.io/qt-5/windows-deployment.html closely