bug#29906: 27.0.50; Emacs prompts for passwords in GUI dialog instead of minibuffer

[Daiki Ueno <ueno@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: nljlistbox2@gmail.com (N. Jackson)
>> Cc: 29906@debbugs.gnu.org
>> Date: Sat, 30 Dec 2017 10:54:31 -0500
>> 
>> At 10:19 +0200 on Saturday 2017-12-30, Eli Zaretskii wrote:
>> >
>> > Does this NEWS.26 entry help?
>> >
>> >   ** The pinentry.el library has been removed.
>> >   That package (and the corresponding change in GnuPG and pinentry)
>> >   was intended to provide a way to input passphrase through Emacs with
>> >   GnuPG 2.0.  However, the change to support that was only implemented
>> >   in GnuPG >= 2.1 and didn't get backported to GnuPG 2.0.  And with
>> >   GnuPG 2.1 and later, pinentry.el is not needed at all.  So the
>> >   library was useless, and we removed it.  GnuPG 2.0 is no longer
>> >   supported by the upstream project.
>> >
>> >   To adapt to the change, you may need to set 'epa-pinentry-mode' to the
>> >   symbol 'loopback'.

I wasn't aware of this entry.  Would it really make sense, given that
pinentry.el was a new library introduced in Emacs 26?

>> Yes, that does help, thank you. I should have checked the news.
>> 
>> It doesn't help me decide what to do though. Do you know if using
>> the prompt in the minibuffer (using `loopback') is thought to be
>> less secure than using the external pinentry program?
>
> I don't know enough about this to tell.  Daiki, any inputs?

I would say it's provides the same level of security as pinentry-gtk,
which no longer uses secmem these days.

It's unfortunate that one of the GnuPG contributors (who currently seems
inactive) had advertised that it was less secure, based on his Emacs 19
knowledge:
https://dev.gnupg.org/T2034#89059

Sigh.  I am really disapponted with the recent development of GnuPG
(failed attempt of standardization, immature implementation of TOFU, FUD
like this, etc).

Regards,
-- 
Daiki Ueno