如何使用OpenSSL安装使QSslSocket支持SSL？

Question

I'm trying to run a simple client/server to implement a communication using QSslSocket. I work on Windows (unfortunately) and I use QtCreator for more convenience.

When I try, from the client side, to connect to the server using MyQSslSocket->connectToHostEncrypted(ip, port) , I get the following message:

qt.network.ssl: QSslSocket::connectToHostEncrypted: TLS initialization failed

When I print the raised error, I get the following one:

QAbstractSocket::SocketError(20)

In the documentation we can find that this error code corresponds to QAbstractSocket::SslInternalError whose the description is:

"The SSL library being used reported an internal error. This is probably the result of a bad installation or misconfiguration of the library."

After some investigations I found that Qt does not provide OpenSSL by itself so I installed it (the binaries, for both 32 and 64 bits versions to be sure) from here https://slproweb.com/products/Win32OpenSSL.html .
During the installation, the dll was copied to C:\\Windows\\System32 (for the 64 bits). Then I checked that the PATH environment variable does well contain this folder.

At this point I tried again, but I still had the same problem, as if the OpenSSL installation was still not found.

When I print the output of the following calls (in the main function of my client):

qDebug() << QSslSocket::supportsSsl();
qDebug() << QSslSocket::sslLibraryVersionString();

I get the following outputs:

false
""

My question is, how to make QSslSocket::supportsSsl() return true ?

If anyone could teach me what I missed, what I am doing wrong and tell me what I should do to be able to make this SSL connection run properly, I would be very grateful.

Fareanor.

PS: Sorry for the long question but I think it is important to clearly expose the problem and the context to help you to easily understand the problem and give me more relevant answers.

Answer 1

Ok, Thanks to @AlienPenguin and @Macias advices, it was that my version of OpenSSL was too recent.

Finally I have installed the closest available version of the one used for the Qt build (which does make sense, I should have thought of it) which can be found by running the following call:

qDebug() << QSslSocket::sslLibraryBuildVersionString();

Problem solved.

Thanks again.