Re: Fix needed for communication with gpg-agent

[Chong Yidong <cyd@stupidchicken.com>]

Werner Koch <wk@gnupg.org> writes:

> On Fri, 23 Feb 2007 17:23, cyd@stupidchicken.com said:
>
>> 2. Documenting the problem in the PGG manual, and recommending using
>>    PGG and gpg-agent in X (for Emacs 22 anyway).
>
> This and for non-X one could suggest to use screen and start gpg-agent
> using the option
>
>  --keep-tty

In that case, I suggest the following patch to the PGG documentation.
What do people think?

*** emacs/man/pgg.texi.~1.16.~	2007-01-17 22:03:18.000000000 -0500
--- emacs/man/pgg.texi	2007-02-23 14:35:46.000000000 -0500
***************
*** 229,236 ****
  @node Caching passphrase
  @section Caching passphrase
  
! PGG provides a simple passphrase caching mechanism.  If you want to
! arrange the interaction, set the variable @code{pgg-read-passphrase}.
  
  @defvar pgg-cache-passphrase
  If non-@code{nil}, store passphrases.  The default value of this
--- 229,279 ----
  @node Caching passphrase
  @section Caching passphrase
  
! When using GnuPG (gpg) as the PGP scheme, we recommend using a program
! called @code{gpg-agent} for caching passphrases@footnote{Actually
! @code{gpg-agent} does not cache passphrases but private keys.  On the
! other hand, from a user's point of view, this technical difference
! isn't visible.}.
! 
! @defvar pgg-gpg-use-agent
! If non-@code{nil}, attempt to use @code{gpg-agent} whenever possible.
! The default is @code{t}.  If @code{gpg-agent} is not running, or GnuPG
! is not the current PGP scheme, PGG's own passphrase-caching mechanism
! is used (see below).
! @end defvar
! 
! To use @code{gpg-agent} with PGG, you must first ensure that
! @code{gpg-agent} is running.  For example, if you are running in the X
! Window System, you can do this by putting the following line in your
! @file{.xsession} file:
! 
! @smallexample
! eval "$(gpg-agent --daemon)"
! @end smallexample
! 
! For more details on invoking @code{gpg-agent}, @xref{Invoking
! GPG-AGENT,,,gnupg,Using the GNU Privacy Guard}.
! 
! Whenever you perform a PGG operation that requires a GnuPG passphrase,
! GnuPG will contact @code{gpg-agent}, which prompts you for the
! passphrase.  Furthermore, @code{gpg-agent} ``caches'' the result, so
! that subsequent uses will not require you to enter the passphrase
! again.  (This cache usually expires after a certain time has passed;
! you can change this using the @code{--default-cache-ttl} option when
! invoking @code{gpg-agent}.)
! 
! If you are running in a X Window System environment, @code{gpg-agent}
! prompts you for a passphrase by opening a graphical window.  However,
! if you are running Emacs on a text terminal, @code{gpg-agent} has
! trouble receiving input from the terminal, since it is being sent to
! Emacs.  One workaround for this problem is to run @code{gpg-agent} on
! a different terminal from Emacs, with the @code{--keep-tty} option;
! this tells @code{gpg-agent} use its own terminal to prompt for
! passphrases.
! 
! When @code{gpg-agent} is not being used, PGG provides its own
! passphrase caching mechanism, which is controlled by the variable
! @code{pgg-read-passphrase}:
  
  @defvar pgg-cache-passphrase
  If non-@code{nil}, store passphrases.  The default value of this
***************
*** 243,256 ****
  Elapsed time for expiration in seconds.
  @end defvar
  
- @defvar pgg-gpg-use-agent
- When using GnuPG (gpg) as PGP scheme you can use @code{gpg-agent} for
- caching@footnote{Actually @code{gpg-agent} does not cache passphrases
- but private keys.  On the other hand, from a users point of view this
- technical difference isn't visible.}.  It defaults to @code{t}.
- Setting this to @code{nil} is not recommended.
- @end defvar
- 
  @node Default user identity
  @section Default user identity
  
--- 286,291 ----