GPG4Win: running gpg-agent with SSH agent support?

[Simon Josefsson]

Werner Koch <wk at gnupg.org> writes:

> On Fri, 29 Jan 2010 14:03, simon at josefsson.org said:
>
>> I've installed GPG4Win and it recognizes my OpenPGP smartcards without
>> problem (via a gpg-agent process which appears to be auto-started
>> somehow?).  However, I'd like to enable SSH agent support in gpg-agent
>
> Yes, we do this on Windows because we have a well known socket name
> there.  It may actually happen that two agents are started which does
> not harm because the the unused agent detects this case and terminates
> itself after some time.
>
>> too, so that Cygwin ssh can make use of it.  Is this possible, if so
>> how?
>
> It can't work out of the box because ssh needs to implement our local
> socket emulation (see libassuan/src/assuan-socket.c).  It would be very
> useful if we could get support for this into putty.

Why can't gpg-agent implement the same protocol that ssh-agent does
under Windows?

The ssh-agent under Cygwin appears to work in the same way it does on
GNU/Linux, i.e., the ssh process looks for the environment variables
that ssh-agent prints when started.

/Simon