It would be good to implement access to GnuPG using GPGME.

Useful operations are:

• list available secret and public keys
• secret key operations (sign and decrypt)
• extract a public key (for importing it into TB)

A mechanism to directly use a secret key, managed by GnuPG, instead of exporting and importing it, would enable us to use smartcards that are supported by GnuPG.

Initial GPGME bindings were already added in bug 1633288.
A fallback attempt to GPGME is currently active.

We should add a pref, that allows the user to disable/enable the use of GPGME.
For now, I'd disable that pref by default, unless we have support for digital signing with GPGME.

We should also change the message that's shown on the debug console. We shouldn't talk about "required GPGME", but rather about "optional GPGME".

This probably doesn't block bug 1627736, moving to "see also".

I tried using gpgme on Windows. It doesn't work directly because both, the binary distribution of GnuPG 2.2 and gpg4win store the library as "libgpgme-11.dll". Attached is a patch that fixes this.

NOTE: Unfortunately gpg4win is only available for Win32. TB for x64 thus can't use the library.

(In reply to Patrick Brunschwig from comment #3)

NOTE: Unfortunately gpg4win is only available for Win32. TB for x64 thus can't use the library.

That's sad.
We might want to ask the developers why.

Patrick, do you know the filename on macOS ?

I'm working on it. The filename is standard, but I fear we will need to manually search for the library (full path). I'll have a patch in a few days.

Here is a patch that makes GPGME work on macOS. Unfortunately, macOS doesn't simply search in /usr/local/lib, such that we need to specify some paths explicitly.

I made the patch generic, i.e. it applies to any non-Windows system.

Specifically for macOS:

• if you use gpgOSX, then GPGME will be found in /usr/local/bin
• if you use brew or fink the GPGME will be found in /opt/local/bin

As mentioned in https://bugzilla.mozilla.org/show_bug.cgi?id=1642614#c22 already, the right library name to load is libgpgme.so.11, not libgpgme.so. The later is installed only as part of devel headers on major distros (at least Debian and Fedora) and are not expected to be present on user machines.

(In reply to Marek Marczykowski-Górecki from comment #16)

As mentioned in https://bugzilla.mozilla.org/show_bug.cgi?id=1642614#c22 already, the right library name to load is libgpgme.so.11, not libgpgme.so. The later is installed only as part of devel headers on major distros (at least Debian and Fedora) and are not expected to be present on user machines.

This was added in bug 1603782.

With all the work that was done in other bugs, we can close this one.