[gdm-list] how to use authentication feature of GDM in a screen saver

[Jedy Wang <Jedy Wang Sun COM>]

Hi maitainers of gdm,

I am a developer from Desktop team of SUN. We plan to implement screen 
saver support for gdm. Currently, I am trying to integrate GUI from 
gnome-screensaver with PAM implemented in GDM and had a problem.

As you know, GDM provides PAM feature through GreeterServer DBus 
interface to simple greeter dialog and I want to use it as the 
authentication backend for screen saver. But this interface is not a 
public one. To call methods provided by GreeterServer, the client has to 
connect to a private bus whose address can only be obtained through a 
shell environment variable in login session. After the login, the 
variable is gone .

The solution I currently have is to add a DBus method (in SimpleSlave 
maybe) which the screen saver process can call to obtain the private bus 
address, then the process can use the address to connect to 
GreeterServer and do authentication staff. But I am not sure if this is 
a good idea because any process in the session can obtain the address 
and may monitor the traffic on the bus. So I wan to know if this is a 
acceptable solution for the community or if there are any better ones?

Thanks,

Jedy