QSslSocket和supportsSsl（）返回false

Question

Background

Basically I need a Openssl support for my application, preferably through dynamic linking. For this I have complied the Openssl libraries using the following:

perl configure VC-WIN32 no-asm --prefix=C:\Build-OpenSSL-VC-32
nmake -f ms\ntdll.mak
nmake -f ms\ntdll.mak test
nmake -f ms\ntdll.mak install

using VC 2017 x86 all tests passed. So far so good. Then I compiled qt5 from source using the following configuration:

configure -debug-and-release -opensource -nomake examples -nomake tests -confirm-license --prefix="C:\Work\qt-bin-5.9-VC-17" -skip webengine -platform win32-msvc -openssl -I C:\Build-OpenSSL-VC-32\include -L C:\Build-OpenSSL-VC-32\lib

The build process succeeded with VC 2017. After this I installed the latest version of qt-creator. Then I configured the qt versions/kits and paths to the newly complied version. No other versions are installed on this computer. Next I created a small program to test if everything is working properly. This resulted in QSslSocket::sslLibraryBuildVersionString() returning OpenSSL 1.0.2l 25 May 2017 (version I compiled) and QSslSocket::supportsSsl() returning false. Note I have included:

 QT       += network
 INCLUDEPATH += C:\Build-OpenSSL-VC-32\include
 LIBS += C:\Build-OpenSSL-VC-32\lib\libeay32.lib
 LIBS += C:\Build-OpenSSL-VC-32\lib\ssleay32.lib

in the .pro file. I've tried adding the .dll instead of the .lib files but I then get the following error.

C:\Build-OpenSSL-VC-32\bin\libeay32.dll:-1: error: LNK1107: invalid or corrupt file: cannot read at 0x2B8

I would really appreciate any help and information about what I did wrong.

Answer 1

It is normal to have an error when you replace the ".lib" by the ".dll", you cannot link directly to a dll. You must link to a ".lib", the ".dll" will be required at execution. But you should not have to link directly to OpenSSL when building your own app, Qt will load them at run-time when they are needed.

QSslSocket::sslLibraryBuildVersionString() returns the version of the SSL library used when you built Qt.

You need to use QSslSocket::sslLibraryVersionString() to get the version number of the run-time SSL library. QSslSocket::supportsSsl() gives info about SSL support at run-time, which may not be available even if SSL support was available when you built Qt itself.

From what you described, it seems that your program fails to find the OpenSSL dll at run-time. Be sure to place libeay32.dll and ssleay32.dll next to your exe file or in your PATH.