Silverlight login failure reason notification

Russ posted on Tuesday, February 02, 2010

Does anyone have a suggestion of how to return the reason a login attempt has failed in a Silverlight application?

It is strictly forbidden to throw an exception in the AppPrincipal or AppIdentity objects during the login process so that a valid Principal (or UnauthenticatedPrincipal) is always returned. This makes it difficult to notify the user of the reason their login attempt failed. Some possible reasons are: incorrect username password combination, password has expired, user account is inactive, server not accepting logins at this time etc.

The reason is detected in the DataPortal_Fetch method of the AppIdentity.Server.cs. The question is how to return that reason to the user. Is there a better method than to simply add a reason property to the AppIdentity class?

Thanks in advance
Russ

RockfordLhotka replied on Wednesday, February 03, 2010

That seems like a reasonable solution. The IIdentity already has IsAuthenticated. If that value is false, it seems reasonable to think there could be a AuthenticationFailureReason property to explain why. Normally it would be null, because normally the user would be authenticated, so the overhead would be quite low.