c# - Sharepoint 2013 authentication -

we have single sign-on (sso) web app used authenticate users in different applications based on username , password. generates random token , saves in database.

to authenticate users in other apps, have http module running on every request, verifies token , sets context user this:

windowsidentity identity = new windowsidentity(currentusername, "windowsauthentication"); windowsprincipal principal = new windowsprincipal(identity); this.context.user = principal; 

this method works in sharepoint 2010 (configured windows authentication). doesn't work new sharepoint 2013 (configured windows authentication well).

1. do have idea why method doesn't work anymore in sharepoint 2013?
2. do have suggestions can try make work?
3. do have suggestions different method of authentication sharepoint 2013?

this looks use case writing custom claims provider me.

http://msdn.microsoft.com/en-us/library/ee537299.aspx

basically when call made sharpoint, going redirect custom claims service. here code run authenticate user , issue token. token honored sp2013 because have established trust relationship between sp2013 , claims provider.