Authenticate don't call custom session or customauth provider

Hi, which function does [Authenticate] attribute call in mvc controller?
have CustomUserSession and CustomAuthProvider.

when i goto [Authenticate] actions in mvc, will return to login page without hit any function in custom user session or custom auth provider.

UserController : BaseController : ServiceStackController<CustomUserSession>

and action

public ActionResult Index(){}

any idea?

The [Authenticate] attribute is executed by the [ExecuteServiceStackFilters] MVC Filter attribute which calls the IsAuthorized() extension method:

if (!ssController.IsAuthorized(authAttr)) 

Which just checks to see the user has a valid Session with IsAuthenticated=true:

public static bool IsAuthorized(this IHasServiceStackProvider hasProvider, AuthenticateAttribute authAttr)
    if (authAttr == null)
        return true;

    var authSession = hasProvider.ServiceStackProvider.GetSession();
    return authSession != null && authSession.IsAuthenticated;

You always give me an answer in time, thanks.