8

Qt requires open ssl libraries to be installed on system. In debian / ubuntu when I install open ssl using apt everything works. But when I compile my application in windows, SSL features are not available I can verify this by executing

QSslSocket::supportsSsl()

How do I make it work in windows? I downloaded and installed open ssl from http://www.slproweb.com/products/Win32OpenSSL.html but it still returns false.

Petr
  • 13,747
  • 20
  • 89
  • 144

3 Answers3

18

So after long time I figured what the problem is:

These 2 libraries need to be in same folder as your executable OR in windows system folder (system32 I think):

libeay32.dll
ssleay32.dll

You will find them in \bin of your OpenSSL folder, since I copied these 2 libs there it works

IMPORTANT: When deploying to client computers, it's also necessary to install vcredist package that was used to compile these .dll which may differ from vcredist package needed to run the application itself. vcredist version depends on version of the libraries.

Petr
  • 13,747
  • 20
  • 89
  • 144
  • 2
    I had a problem installing too new version so for others still having this issue: check `QSslSocket::sslLibraryBuildVersionString();` and make sure to install the same X.Y version of OpenSSL (I was using 1.1.0 but needing 1.0.X) – michnovka Oct 12 '16 at 00:19
  • The DLLs can be found there: http://gnuwin32.sourceforge.net/packages/openssl.htm in the Windows "Binaries" package. – laurent Jan 02 '17 at 12:02
  • @TomášNavara This should be the correct answer. The Qt SSL docs say that Qt is compatible with OpenSSL 1.0+ or something like that but it seems it will not load a library with a version different from what `QSslSocket::sslLibraryBuildVersionString();` returns. It will load one with a different suffix letter (bug fix version increment). It did for me. – Paul-Sebastian Manole May 04 '17 at 09:41
9

You have to add OpenSSL lib in your project. In windows Qt doesn't come with OpenSSL lib. (I think it's a legal issue). You can find OpenSSL developer libs in URI you posted. If you are compiling against 32bit framework, what you need to download is Win32 OpenSSL v1.0.1e

This is what I have in my project.

QT += core gui network
win32{
    LIBS += -LC:/OpenSSL-Win32/lib -lubsec
    INCLUDEPATH += C:/OpenSSL-Win32/include
}
Dasun
  • 3,244
  • 1
  • 29
  • 40
  • 1
    I did what you say, cleaned, rebuilt and still it it's false – Petr Dec 04 '13 at 09:31
  • What is the exact qt Version you use? It worked fine in Qt 5.1 and I'm currently using in Qt 5.2 R1 too. – Dasun Dec 04 '13 at 09:50
  • Did you add network module in your project file? "Qt += network". and don't forget to run "qmake". Sometimes qt does't seems to udnerstand that we have changed the project file. – Dasun Dec 04 '13 at 09:59
  • 1
    QT 5.1.1 I have network module, as I said, it works on linux, just not on windows. And yes I did clean all, ran qmake and make, still it doesn't work in windows. Btw I am using mingw to compile – Petr Dec 09 '13 at 12:47
  • May be it is a MinGW related issue. I'm using VC++. I gave up MinGW due to lack of Angle support. – Dasun Dec 09 '13 at 16:22
  • Following brokenthorn's suggestion above, these .pro lines are working with "Win32OpenSSL-1_0_2p.exe" in 2018. – CodeLurker Nov 06 '18 at 10:49
2

As you figured out already, you were missing dlls. Here is more information

Check what version of ssl you need with

QSslSocket::sslLibraryBuildVersionString();

For ssl 1.0.x (qt<5.12.4) you are likely missing libeay32.dll and ssleay32.dll.

For ssl 1.1.x (qt>=5.12.4) binary compatibility broke (qt 5.12.4 released), so you might need libssl-1_1.dll and libcrypto-1_1.dll, and its dependencies capi.dll and dasync.dll.

convexbytes
  • 184
  • 1
  • 6