Is it possible share authentication between Asp.NET web applications and silverlight business application

Question

Is it possible share authentication between Asp.NET web applications and silverlight business application?

Scenario: When uses logged in on either SL application or Asp.NET application using same browser, I want them to used active authentication. I have seen OpenId authentication can do such, But wondering can asp.net authentication is also able to do such.

Answer 1

Yes the authentication infrastructure can be shared between ASP.Net and SilverLight. If both the sites are under one domain, we can implement the standard authentication using ASP.Net Membership and role provider.
You can then use the WCF Authentication Service to and authorize user. This authentication is is good only for any server side functionality. If you want to authorize on client side (SilverLight) application you need to build your own infrastructure. Role and Membership provider data available can help you in that.

Answer 2

You can host your SL application in ASP.NET page and when somebody comes on this page do authentication. For instance, you can use FormAuthentication on the site, so when you are navigating from some page to page with Silverlight - access will be hovered by very FormAuthentication. OpenId you can use if ASP.NET app and Silverlight on different sites (domains), but if the Silverlight app is hosted on asp.net page you can also authenticate using asp.net infrastructure on server side.