Problem installing QCA-OSSL (part of the Qt Cryptographic Architecture) plugin on Windows 7

Question

I have been trying to use QCA (Link) on my Windows PC for a couple of days now, works fine on my linux box, just can't get it working with Windows.

So i followed all the instructions for installing QCA and then the ossl plugin for QCA. The QCA works fine but for some reason the plugin isn't showing up in my Qt Creator nor am I able to use some of the functions in the plugin.

I used the qcatool2.exe that comes with QCA to check my plugins using

qcatool2 plugins --debug

and get this error message:

plugin: qca-ossl2.dll: failed to load: The plugin 'C:/Qt/2010.05/qt/plugins/crypto/qca-ossl2.dll' uses incompatible Qt library. Expected build key "Windows mingw debug full-config", got "Windows mingw release full-config"

Now this seems to me as if qt requires the plugin to be compiled in debug mode (as to get the build key to contain debug rather than release) so I added

CONFIG += debug

to my plugin's project file and ran qmake and mingw32-make as usual but this seems to have had no effect.

My project file for the plugin is now:

TEMPLATE = lib
CONFIG += plugin
QT -= gui
DESTDIR = lib

VERSION = 2.0.0

unix:include(conf.pri)
windows:CONFIG += crypto
windows:include(conf_win.pri)

CONFIG += create_prl

SOURCES = qca-ossl.cpp

windows:{
load(winlocal.prf)
isEmpty(WINLOCAL_PREFIX) {
error("WINLOCAL_PREFIX not found. See http://delta.affinix.com/platform/#winlocal")
}

OPENSSL_PREFIX = $$WINLOCAL_PREFIX
DEFINES += OSSL_097

INCLUDEPATH += $$OPENSSL_PREFIX/include
LIBS += -L$$OPENSSL_PREFIX/lib
LIBS += -llibeay32 -lssleay32
LIBS += -lgdi32 -lwsock32
}

!debug_and_release|build_pass {
CONFIG(debug, debug|release) {
mac:TARGET = $$member(TARGET, 0)_debug
windows:TARGET = $$member(TARGET, 0)d
}
}

CONFIG += debug

Has anyone got any ideas? If you need anymore details just ask, I've tried to be as thorough as possible. Thanks

Tom

Answer 1

I've been struggling with a similar situation: qca-ossl builds fine on linux and not at all on windows. I just hit a breakthrough which might help you as well.

Versions and Patches

• qtsdk-2010.05
• qca-2.0.3
• qca-ossl-r1190163 (from the repository)
• openssl-1.0.0b

First of all, if you're using a newer version (0.9.7+, I think) of OpenSsl, you may need to use the qca-ossl version from the repository since it patches some incompatibilities. I also needed to comment out some lines in the new qca-ossl.cpp file dealing with SHA224, SHA256, SHA384, and SHA512 to avoid build errors. I'm using qca-ossl for the ciphers, so I'm not worried about hashing and didn't investigate the errors very much.

Fixing It

The windows build problems were many fold for me, but most of them stem from the shoddy build setup for the windows version of the plugin. It's nice having a little configure script for the linux side of things, but what about windows? We need to do a little extra work.

Some of this extra work is because I've chosen non-standard locations for the support libraries of my application. Qca and OpenSsl both exist within the project's directory structure in a libraries/ directory. My guess is that you've done something similar if you are trying to cross compile your application, but even if you didn't the following should help.

Finding OpenSsl

Qca-ossl wont build very well if it can't find the library it's supposed to connect to... :) So let's specify directly where it is. Comment out the lines relating to winlocal.prf and the changes that stem from it in qca-ossl.pro. We will directly specify where to find openSsl.

TEMPLATE = lib
CONFIG += plugin
QT -= gui
DESTDIR = lib

VERSION = 2.0.0

unix:include(conf.pri)
windows:CONFIG += crypto
windows:include(conf_win.pri)

CONFIG += create_prl

SOURCES = qca-ossl.cpp

windows:{
# Rather than rely on the winlocal.prf file, we will specify the location of the openssl
# by hand when running qmake.
#
# load(winlocal.prf)
# isEmpty(WINLOCAL_PREFIX) {
# error("WINLOCAL_PREFIX not found. See http://delta.affinix.com/platform/#winlocal")
# }
#
# OPENSSL_PREFIX = $$WINLOCAL_PREFIX
DEFINES += OSSL_097

INCLUDEPATH += $$OPENSSL_PREFIX/include
LIBS += -L$$OPENSSL_PREFIX/lib
LIBS += -llibeay32 -lssleay32
LIBS += -lgdi32 -lwsock32
}

!debug_and_release|build_pass {
CONFIG(debug, debug|release) {
mac:TARGET = $$member(TARGET, 0)_debug
windows:TARGET = $$member(TARGET, 0)d
}
}

Now we have direct access to the $$OPENSSL_PREFIX environment variable in the .pro file. We can set it when we call qmake by doing the following.

qmake.exe "OPENSSL_PREFIX=C:/path/to/openssl-1.0.0b"

You should be able to use backward slashes or forward slashes. Here I choose forward since Qt has deprecated them since 4.7.

Alternatively, you could set the OPENSSL_PREFIX variable directly in the .pro file.

Finding Qca

After comparing the unix and windows makefiles for qca-ossl, oddly enough, it never includes the qca libraries for building or linking! ?!?! This led to an "Undefined interface" error on the Q_INTERFACES(QCAPlugin) line of the opensslPlugin class definition at the end of qca-ossl.cpp.

To avoid this, we will need to explicitly define the include and library paths by hand. Expanding on the qmake line from the last section the final qmake line is as follows.

qmake.exe "OPENSSL_PREFIX=C:/path/to/openssl-1.0.0b" "INCLUDEPATH+=C:/path/to/qca-2.0.3/include/QtCrypto" "LIBS+=-LC:/path/to/qca-2.0.3/lib -lqca2"

"Installing" Qca-ossl

After running the qmake line above and running a plain ol' make, you'll need to install Qca-ossl. You can copy the resulting dll from the lib/ directory to your Qt's plugins directory, which if you're using my versions defaults to C:\Qt\2010.05\qt\plugins\crypto. Alternatively, you can move it to a crypto directory that's at the root level of your project's directory structure such as C:\path\to\my\project\crypto.

I hope this helps!

Answer 2

Actually, you can try this tutorial QCA+OpenSSL on Window. It's work well.

By the way, I can make use of QCA with AES 256 on Window. But i can't use it on Symbian. Any idea to do it?

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