The pam_ck_connector PAM module registers a login session with the system-wide ConsoleKit daemon. This PAM module should be used with caution; only local login managers such as login(1) should use this. Since the ConsoleKit daemon can accept both an tty and an X11 display the normal parameters set by PAM are not always useful.
An application can therefore override these with the PAM environment variables CKCON_TTY, CKCON_X11_DISPLAY and CKCON_X11_DISPLAY_DEVICE (the application should remember to unset these before starting the login session).
Also note that the ConsoleKit daemon may reject registration attempts if the given set of data are inconsistent with each other. More more information, see the ConsoleKit documentation on the OpenSessionWithParameters() method call on the org.freedesktop.ConsoleKit.Manager D-Bus interface.
If registration with the ConsoleKit daemon succeeds, this PAM module will set the environment variable XDG_SESSION_COOKIE which is used to defined membership of a login session.
This PAM module has the side effect that it creates a connection to the system message bus that is kept open until the session ends. This is used by the ConsoleKit daemon to track the life-cycle of the session and, as such, should the login manager crash, the session will be properly unregistered.
pam.conf(5), pam.d(8), pam(8), dbus-daemon(1)