I am creating a custom authentication module in DNN in order to authenticate my users against a custom WebSTS (WSFederation).

Creating a custom login control to ask for the proper STS credentials is not a problem, but my problem is with creating a custom logoff control. I want a custom logoff control so I have full singlesignon/singlesignout functionality which logs me in and off both in DNN and at the WebSTS (or ADFS for that matter).

I have implemented my Logoff.ascx in the same manner as I have implemented my Login.ascx in my authentication module.

I am using a clean installation of DNN version 06.02.01 (253).

So far I have only found solutions which suggest modifying the DNN source, which I prefer not to do because this will break with a version upgrade. I have also seen a suggestion to set the 'Redirect after logout' parameter in the site settings and point this to some control which sends/handles the logout on the STS. But this I do not prefer either because then my module would not work out of the box.

So my question basically is, is there a way to have a single custom authentication module which could handle both login and logoff logic in this way? Reading its sourcecode I would think so. I am new to DNN, so detailed instructions would be much appreciated.