Using QSslSocket with custom OpenSSL

SGaist · wrote on 1 Nov 2016, 20:22

You can build Qt with the -openssl-linked option and point configure to your self-built version of OpenSSL.

Opa114 · wrote on 4 Nov 2016, 11:15

@SGaist said in Using QSslSocket with custom OpenSSL:

You can build Qt with the -openssl-linked option and point configure to your self-built version of OpenSSL.

i tried it that way, but buildung QT 5.7 with OpenSSL 1.1.0b ist not supported till QT 5.9 because in OpenSSL are some changes done, so that building QT 5.7 with that new OpenSSL version did not work. See here: https://bugreports.qt.io/browse/QTBUG-52905

Then i tried it with an older version of OpenSSL (1.0.2j) - this works.

But what ist the difference between building Qt gainst OpenSSL with -openssl on running the configure-command and to link against the OpenSSL headers and libs and build it inside the Project? If i build against OpenSSL i have to include the headers anyway to work with the libs if i want to use the OpenSSL specific stuff.

And i noticed that i can replace the built in OpenSSL libs with the own build one. So it would be much simpler to include the ehaders of OpenSSL via INCLUDEPATH. So i get OpenSSL support = true on output of: qDebug() << QSslSocket::supportsSsl();

And if print out his i got the Output which i wrote behind:
qDebug() << QSslSocket::sslLibraryBuildVersionString(); // OpenSSL 1.0.2g 1 Mar 2016
qDebug() << QSslSocket::sslLibraryVersionString(); // OpenSSL 1.0.2j 26 Sep 2016

Why is the first one at all time: OpenSSL 1.0.2g 1 Mar 2016 - This i got, too if i build Qt at own and link against OpenSSL 1.0.2j??

SGaist · wrote on 4 Nov 2016, 19:13

It's in the docs:
sslLibraryBuildVersionString is returning the version of the OpenSSL library used when building Qt.
sslLibraryVersionString is returning the version of the OpenSSL library used at run time.

By default OpenSSL is dlopened because some countries have restrictions about encryption related software and OpenSSL can't be distributed just like that.

Opa114 · wrote on 4 Nov 2016, 19:19

Thanks! But why are my versions different?
I build Qt with OpenSSL 1.0.2j, so both outputs must be the same or not?

SGaist · 4 Nov 2016, 19:32

Silly question but are you sure that you are using your self-build Qt in your kit ?

Opa114 · 11 Apr 2016, 19:40

@SGaist said in Using QSslSocket with custom OpenSSL:

Silly question but are you sure that you are using your self-build Qt in your kit ?

yes :)
could it have to do with Qt-Creator, which was build with another version?

SGaist · 4 Nov 2016, 22:21

No, the Qt version used to build Qt Creator doesn't affect any any way the Qt version you are using with your kit.

Do you have another OpenSSL version installed on your system ?

Opa114 · S SGaist 4 Nov 2016, 20:26

@SGaist said in Using QSslSocket with custom OpenSSL:

on used to bui

no not installed like the precompiled OpenSSL Libraries. I searched the whole PC (Windows) for OpenSSL and libeay32.dll. I found many applications which are using OpenSSL but only one Application uses the specific OpenSSL version OpenSSL 1.0.2g 1 Mar 2016 i posted above. This Application is Adobe Lightroom.

Could this be the problem on building Qt that some shipped libeay32.dlls are used on build process?

CarlosQ · S SGaist 4 Nov 2016, 20:26

@SGaist Sorry, i have the same problem.
When i print:
qDebug() << QSslSocket::supportsSsl(); ==> false
qDebug() << QSslSocket::sslLibraryBuildVersionString(); ==> "OpenSSL 1.0.2g 1 Mar 2016"
qDebug() << QSslSocket::sslLibraryVersionString(); ==> ""

and i obtain these messages:
qt.network.ssl: QSslSocket: cannot call unresolved function SSLv23_client_method
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_CTX_new
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_library_init
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error
qt.network.ssl: QSslSocket: cannot call unresolved function ERR_get_error

I have instaled only Qt 5.7 on Windows 7 32. What can i do?
Thanks

SGaist · 7 Dec 2016, 09:09

Hi,

Do you have OpenSSL installed ? Built with the same compiler as Qt ? In a folder known to your application ?

CarlosQ · S SGaist 5 Dec 2016, 20:25

@SGaist No, no and no. Ohhhh. i'll try to build the libraries.

Sorry, thanks.

SGaist · 11 Dec 2016, 13:55

You can find here prebuilt versions of OpenSSL for various compilers.

CarlosQ · S SGaist 7 Dec 2016, 20:54

@SGaist Thank you for the link. I was trying to build the libraries and I'm going crazy.

I have Qt 5.7.0 on a Windows 7 32 bits, which instalation should be correct?. I think "Win32 OpenSSL v1.1.0c". Is it ok?.

Thanks again.

SGaist · wrote on 11 Dec 2016, 20:58

IIRC there was a renaming of the libraries of OpenSSL so you'll have to double check.