Re: epa.texi: Emacs and GnuPG pinentry

[Jens Schmidt <jschmidt4gnu@vodafonemail.de>]

On 2023-08-14  12:13, Björn Bidar wrote:

> I'm not 100% sure but I think not all pinentry's support loopback.
> The user has to make sure that his does support it.

Hm ... that let me worry a bit, since I updated the documentation
in epa.texi some time ago already.  So I tested, all running from an
Emacs 27 -Q:

*** epg-pinentry-mode == nil

echo RELOADAGENT | gpg-connect-agent
# only pinentry executable on my system
sudo chmod a-x /usr/bin/pinentry-gnome3

(setq epg-pinentry-mode nil)

C-x C-f ~/tmp/test/xxx.pgp

=>

  Error while decrypting with "/usr/bin/gpg":

  gpg: encrypted with 3072-bit RSA key, ID D0EB77D91C0802D6, created 2022-12-03
        "test-key"
  gpg: public key decryption failed: No pinentry
  gpg: decryption failed: No secret key

So far so expected.

*** epg-pinentry-mode == 'loopback

echo RELOADAGENT | gpg-connect-agent
sudo chmod a-x /usr/bin/pinentry-gnome3

(setq epg-pinentry-mode 'loopback)

C-x C-f ~/tmp/test/xxx.pgp

=> file gets found and decrypted without problems

From that test I'd conclude that loopback pinentry works even if no
pinentry executable is available at all, so I somewhat doubt that
some pinentry executables would not support it.

Or did I misunderstand you here?  Or do you have further information?

Thanks!