ASP.NET MVC - Dynamic Authorization

Question

I am building a simple CMS in which roles are set dynamically in the admin panel. The existing way of authorizing a controller method, adding [Authorize(Roles="admin")] for example, is therefore no longer sufficient. The role-action relationship must be stored in the database, so that end users can easily give/take permissions to/from others in the admin panel. How can I implement this?

Answer 1

If you want to take control of the authorization process, you should subclass AuthorizeAttribute and override the AuthorizeCore method. Then simply decorate your controllers with your CmsAuthorizeAttribute instead of the default.

public class CmsAuthorizeAttribute : AuthorizeAttribute
{
    public override virtual bool AuthorizeCore(HttpContextBase httpContext)
    {
        IPrincipal user = httpContext.User;
        IIdentity identity = user.Identity;

        if (!identity.IsAuthenticated) {
            return false;
        }

        bool isAuthorized = true;
        // TODO: perform custom authorization against the CMS


        return isAuthorized;
    }
}

The downside to this is that you won't have access to ctor-injected IoC, so you'll have to request any dependencies from the container directly.