Claims aware ASP application

We have a classic ASP application on Windows Server 2003 sp2. We have .net 3.5 installed on that server. We need to make that ASP application Claims Aware (ADFS in our case).

We can't rewrite the ASP site. We can't move it to a different server.

What are the options I have?

Can I write a httpModule and wrap the ASP application with .net? httpModule will be made claims aware and I can set the Server Variable for username. the ASP application know what to do with that username.

Any suggestion is most welcome. 

Thanks