Re: Fix needed for communication with gpg-agent

[Sascha Wilde <wilde@sha-bang.de>]

Werner Koch <wk@gnupg.org> wrote:
> On Thu, 22 Feb 2007 19:40, cyd@stupidchicken.com said:
>> > Is it possible to enhance server-start/emacsclient so that it does not
>> > edit a file but asks for string and returns that one?  Pinentry could
>> > then use this feature for user interaction.
>>
>> I'm not sure how this suggestion could work.
>
> Recall that pinentry is called on the sole discretion of gpg-agent.
> Only gpg-agent knows whether Pinentry needs to be called.
>
> My suggestion is this:
>
>  +-------+    +-----------+    +-----------+       +----------+
>  | emacs | -> | gpg/gpgsm | -> | gpg-agent | ----> | pinentry |
>  +-------+    +-----------+    +-----------+ (may) +----------+
>      ^                                                  |
>      |                                                  |
>      +--------------------------------------------------+
>            (some mechanism to loop back to emacs)
>
> Pinentry uses this:
>
>   if DISPLAY set
>      Use GUI mode; no problem
>   else if SOME_EMACS_ENVVAR set
>      Loop back to emacs
>   else 
>      Use Curses

This looks very good to me, BUT: this would need a new (extended)
version of pinentry, which will probably not be available in most
major distributions for the near future, so I don't think this would
be a feasible solution for the 22 release.

> to decide wether that emacs loop back method is to be used.  It will
> then ask emacs: Please create a form or a minibuffer with this or that
> description and return the user input to me.
>
> I don't know the emacsclient protocol and whether it can easiliy be
> enhanced for that case.

I don't know that either, but we could always create a dedicated
socket for such an service, so yes, I think this would be the right
thing to do -- after the release.

cheers
sascha
-- 
Sascha Wilde
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