如何在Web表单和MVC2应用程序之间共享基于.net（C＃）的身份验证会话？

We have a small application we built in our spare time using the latest mvc3 and Entity Framework .net libraries available at the time, and deployed it. The management liked it, and they want it integrated into a heavy legacy .net 3.5 web forms application. We have a small application we built in our spa