title: Forms authentication + ASP.NET MVC absolute ReturnURL
body: <p>I have a central authentication application on server a. Server b has one or more applications on the same domain that need to authenticate from server a. It's easy enough to set it up so that the server b apps redirect out to server a. What's not so easy is getting the ReturnURL to be absolute.</p>
  
  <p>Here's the wrinkle. Consuming app on server b has two controllers, one public and one secured. If the [authorize] decoration is placed on an action in the public (which is the default controller), I get the proper absolute URL. However, if its in it's own controller I get a relative URL.</p>
  
  <p>I can intercept the on pre-request event in the consuming applications, but I need some parts of the site to be public, not the whole smash.</p>
  
  <p>Ideas?</p>