My current task is evaluation crypto (here: OpenPGP) solutions for Microsoft Windows; of course including GnuPG.
Well, what do I say. While there is a nice installer for GnuPG on Windows available (either here or here), try to find one for the gpgme supporting library… (including header and .lib import files for Visual Studio, that is).
You can guess… It’s all about build-your-own-stuff. It basically boils down to this:
Preparations
- Create a directory to collect all the stuff you will need (e.g.
C:\gpgme
withbin
,include
andlib
sub folders) - Get mingw and install it
- Get MSYS and install it
- Download libgpg-error and extract it
- Download gpgme and extract it
Compiling libgpg-error
- In the MSYS bash, change to the directory you extracted libgpg-error into and run
./configure --prefix=/mingw && make install
- Call
strip src/.libs/libgpg-error-0.dll src/gpg-error.exe
as MSVC can’t use gcc’s debug info anyway - Copy
src/gpg-error.exe and src/.libs/libgpg-error-0.dll
to the bin directory created above - Copy
src/.libs/libgpg-error-0.dll.def
tolib/libgpg-error-0.def
(note the renaming; otherwise your program will look for alibgpg-error-0.dll.dll
) - Open the Visual Studio Command Prompt
- Call
lib /machine:i386 /def:lib\libgpg-error-0.def /out:lib\libgpg-error-0.lib
to create the import library - Copy
include/gpg-error.h
to include
Compiling gpgme
- In the MSYS bash, run
./configure --prefix=/mingw && make
- Call
strip src/gpgme-w32spawn.exe src/.libs/libgpgme-11.dll
- Copy
src/gpgme-w32spawn.exe
tobin
Note: To use the gpgme library, this binary has to live either in the installation dir of gpg (set in windows registry keyHKLM\Software\GNU\GnuPG\Installation Directory
) or in%PROGRAMFILES%\GNU\GnuPG
. Otherwise gpgme will not work! - Copy
src/.libs/libgpgme-11.dll
to bin andsrc/.libs/libgpgme-11.dll.def
tolib/libgpgme-11.def
(Once again, note the renaming) - Call
lib /machine:i386 /def:lib\libgpgme-11.def /out:lib\libgpgme-11.lib
to create the import library - Copy
include/gpgme.h
toinclude
Optional: Creating the documentation
I was not able to create the documentation properly using cygwin so I did this on a Linux host. Install a TeX distribution of your choice as well as texinfo (for Debian Lenny this would mean installing the packages texinfo, texi2html and texlive). Call make pdf in the doc subdir to generate the PDF documentation and manually call texi2html gpgme.texi
for a HTML document.
Summary
Now you can add the lib dir to your Visual Studio linker settings and the include dir to your C/C++ common settings. To make gpgme work, be sure you have the gpgme-w32spawn.exe installed properly as noted above.
I hope this helps to guide one or another through the struggle of getting gpgme on windows.
Q&A
-
Q: gpgme does not find libgpg-error
A: You did not call
make install
after compiling it -
Q: My program is looking for
{libgpg-error-0.dll.dll|libgpgme-11.dll.dll}
A: You did not rename the .def file before calling
lib.exe
-
Q: I did everything you said, but when I run my program,
gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP)
fails withGPG_ERR_INV_ENGINE
. If I check the engine info,info->version
is emptyA: First of all, check if you copied
gpgme-w32spawn.exe
to the correct directory. If this is the case, actually, I have no idea what went wrong
For anyone who wants to use gpgme from windows in a simple way and compiling your programs with cl from your comfortable and cozy cmd or from visual studio (I’ve only tried it in vs2019) can do the following:
1- install gpg4win (I used the latest version available 3.1.9)
2- copy the include directory (from the gpg4win installation folder) to the directory of your project
3- copy libgpg-assuan.imp, libgpg-error.imp and libgpgme.imp from gpg4win to your project directory. In your program write
// to use these libraries
#pragma comment(lib, “libgpg-assuan.imp”)
#pragma comment(lib, “libgpg-error.imp”)
#pragma comment(lib, “libgpgme.imp”)
5- compile: cl my_program.c /I include
If you find an error related to gpgme-w32spawn.exe you can copy it to your project directory (this program is also in the gpg4win installation directory) or you can use this inside your code:
gpgme_set_global_flag(“w32-inst-dir”, “C:\\Program Files (x86)\\Gpg4win\\bin”);
Well yes. That was written 10 years ago, I surely hope things have improved since then 😉