Can you enable [Authorize] for controller but disable it for a single action?

Question

I would like to use [Authorize] for every action in my admin controller except the Login action.

[Authorize (Roles = "Administrator")]
public class AdminController : Controller
{
    // what can I place here to disable authorize?
    public ActionResult Login()
    {
        return View();
    }
}

Answer 1

I don't think you can do this with the standard Authorize attribute, but you could derive your own attribute from AuthorizeAttribute that takes a list of actions to allow and allows access to just those actions. You can look at the source for the AuthorizeAttribute at www.codeplex.com for ideas on how to do this. If you did, it might look like:

[AdminAuthorize (Roles = "Administrator", Exempt = "Login, Logout") ]
public class AdminController : Controller
{
    public ActionResult Login()
    {
        return View();
    }

    public ActionResult Login()
    {
        return View();
    }

    ... other, restricted actions ...
}

Answer 2

You could override the OnAuthorization method of the controller

    protected override void OnAuthorization(AuthorizationContext filterContext)
    {
        if ((string)(filterContext.RouteData.Values["action"]) == "Login")
        {
            filterContext.Cancel = true;
            filterContext.Result = Login();
        }
    }

This works but it is a hack.

Full class code used for testing:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Ajax;

namespace MvcApplication2.Controllers
{
[HandleError]
[Authorize]
public class HomeController : Controller
{
    public ActionResult Index()
    {
        ViewData["Title"] = "Home Page";
        ViewData["Message"] = "Welcome to ASP.NET MVC!";

        return View();
    }


    public ActionResult About()
    {
        ViewData["Title"] = "About Page";

        return View();
    }


    protected override void OnAuthorization(AuthorizationContext filterContext)
    {
        if ((string)(filterContext.RouteData.Values["action"]) == "Index")
        {
            filterContext.Cancel = true;
            filterContext.Result = Index();
        }
    }
}
}