IsGoodMonsterPolicyRequirement.cs

public class IsGoodMonsterRequirement : AuthorizationHandler<IsGoodMonsterRequirement>, IAuthorizationRequirement
{
    protected override void Handle(AuthorizationContext context, IsGoodMonsterRequirement requirement)
    {
        Console.WriteLine("Is a good monster?");

        if (!context.User.Identity.IsAuthenticated)
        {
            Console.WriteLine("... is authenticated...");
        }

        if (context.User.HasClaim(CookieMonsterSecurity.MonsterTypeClaim, CookieMonsterSecurity.MonsterTypes.Good))
        {
            Console.WriteLine("... and has the MonsterTypeClaim = MonsterTypes.Good!");
            context.Succeed(requirement);
        }
    }
}