[pkg-gnupg-maint] Bug#919856: Bug#919856: gpg-agent: agent refuses operation again

[NIIBE Yutaka]

Thanks for your patience.

I think I identified an issue in your debug log.  Not yet catch the bug,
though.

The problem is caching passphrase by libsecret using
gnome-keyring-daemon.  I believe that possible workaround is having
"no-allow-external-cache" in your .gnupg/gpg-agent.conf.


Let me explain, following the log...

	> 2019/01/24 12:02:47.157702  length=37 from=15 to=51
	OPTION allow-external-password-cache
	< 2019/01/24 12:02:47.157773  length=3 from=40 to=42
	OK

Here, gpg-agent sets allow-external-password-cache option.

	> 2019/01/24 12:02:47.159062  length=54 from=536 to=589
	SETKEYINFO s/A337DE390143074C6DBFEA64224359B9859B02FC
	< 2019/01/24 12:02:47.159127  length=3 from=193 to=195
	OK

Here, gpg-agent informs pinentry for keyinfo (it works as cache
identifier).  "s/" stands for SSH, and A3...FC is the keygrip.

And then, GETPIN is issued from gpg-agent, (I think) pinentry must
examine the cache by the function
secret_password_lookup_nonpageable_sync in libsecret.

	> 2019/01/24 12:02:47.159342  length=7 from=723 to=729
	GETPIN
	< 2019/01/24 12:02:47.175799  length=25 from=202 to=226
	S PASSWORD_FROM_CACHE
	OK

This means cache hits, and passphrase is "" (empty).  This is wrong.

I guess, for some unknow reason, secret_password_lookup_nonpageable_sync
seems to return "", where NULL is expected (because of no cache hit).
Something is going wrong in libsecret, it is related to gnome-keyring
service.


In GNOME Desktop, it is gnome-keyring-daemon which handles secret store.
Please check your gnome-keyring-daemon is running correctly.  It's in
gnome-keyring package.

You are using gpg-agent as ssh-agent.  Please don't activate
gnome-keyring-daemon's feature as ssh-agent.
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