WCF Rest Service hosted in Sharepoint (ISAPI folder) doesn´t prompt for credentials

I have a custom WCF Rest Service hosted in Sharepoint (ISAPI folder) and the FBA is enabled in my WebApplication.

The problem is that I´m being able to consume my WebServices without a previous login in sharepoint. Also (just for now), I´m trying to avoid developing a custom token-based solution. The behavior that I´m expecting is that the WS redirects me to my custom login if I´m not already logged in.

Is there any way to do that?

More info:

• If i disable Claims it asks me for login (Windows auth).


• The Rest Api was created using the following tutorial http://ift.tt/1ttH91T