[gdm-list] Should I modify gdm? (I have PAM problems)

["Jose Guillen" <prbulk gmail com>]

Hi,
I'm working on a research project that aims to develop a portable
authentication platform over bluetooth. Here's the lowdown:
1 I walk to my computer, and see the logon prompt
2 I whip out my bluetooth-enabled phone, I select the user "bob" from a list
3 The portable authentication daemon on my PC authenticates with the phone
4 The daemon sends a call to the logon prompt to logon with the username "bob"

It took me six months to implement this on Windows XP. I had to
rewrite the GINA and a new Authentication Package from scratch. Now
I'm looking to do this with Linux using PAM and gdm. My problem is
that the user needs to be able to use a regular username/password
along with this bluetooth authentication mechanism. Also, I'd like to
obviate the need for user-PC interaction (that is, I don't want the
user to have to press 'enter' to start the bluetooth logon process).
At the moment, I can't do both. The user either has to press enter, or
I have to sacrifice normal user/password authentication. This is
because gdm won't call pam_authenticate until the user presses
'enter'. The alternative is to turn on automatic-login, and have
pam_authenticate sleep until someone authenticates over bluetooth.
Is there some way I can have my cake and eat it too without having to
modify gdm directly? I'd like to do this in a clean modular way, if
possible.
Thanks,
Peter R