[gdm-list] Custom greeter

[intrigeri <intrigeri boum org>]

Hi,

I'm part of the people who develop Tails [1], a Live DVD/USB aimed at
preserving privacy and anonymity.

Tails is currently based on Debian Squeeze, and ships GDM 2.30.5 with
a custom greeter we call tails-greeter [2] [3]. It was quite easy to
implement our custom GDM greeter at this point, thanks in particular
to the GreeterServer D-Bus API. The integrated support for setting the
keyboard layout was really helpful too. I'd like to thank everyone who
made this possible for us, if they're still around.

  [1] https://tails.boum.org/
  [2] http://git.immerda.ch/?p=tails/tails-greeter.git
  [3] https://tails.boum.org/doc/first_steps/startup_options/#index2h1

We are soon going to rebase Tails on top of Debian Wheezy, that
includes GDM 3.4.1, which seems to change lots of things about
greeters. So, we now have to seriously consider our options wrt.
the future of our custom greeter. I'm pretty sure we can overcome the
loss of the keyboard layout setting feature... if there are not too
many serious blockers along the road of adapting tails-greeter to
GDM 3.x.

My initial naive attempts to plug tails-greeter into GDM 3.4.1 were
not successful. I did this two months ago and I'm sorry I've not kept
detailed notes of these early attempts. If anyone is interested
enough, I can retry and provide details.

I was not able to find any up-to-date documentation about how one can
write a custom greeter for GDM 3.x, what requirements it must satisfy,
and how one may plug it into GDM's GNOME session so that it replaces.

So, my questions are:

  * Is there any documentation for custom greeter writers?

  * Is the "custom greeter" usecase something the GDM developers are
    interested to support on the long run?

  * Are you aware of any existing custom greeter for GDM 3.x?
    Even a trivial proof-of-concept would do.

Cheers,
-- 
  intrigeri
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