I had hosted WCF on Azure and would like to redirect any request to STS first if not authenticated.
So, if user typed following : http://....../mywcfservice.svc, in the address bar, it should first redirect to STS login page if not authenticated.
I had already implemented same in WebApplication, but when implemented the same configuration in WCf, it doesn’t redirects to sts login but it just shows – “Access is denied”
Why is it not redirecting it to STS Login page?
WCF does not use redirect – the same as your WCF clients are not browser clients. You need to use WS-Trust to do STS-based authentication in WCF. (see ws2007FederationHttpBinding in WCF docs).