I have been playing around with pam-dbus on a old slow box that is too slow for gnome/kde so I have been using ratpoision as the window manager. I was able to configure it to show a notification on the desktop whenever an authentication attempt was made, but I can't figure out how to approve/disapprove the attempt.
pam-dbus uses a feature where a notification contains not only text, but can also allows for Yes-No-interaction. Not all providers of notifications support that feature, if yours does not then you cannot use pam-dbus.
You can check that your notification daemon supports action using this script:
#!/usr/bin/python import pynotify pynotify.init("pam-dbus-test") n = pynotify.Notification("Title","Text") n.add_action("action", "An action", lambda _: False) n.show()