ASP.NET MVC Attribute Supporting SSL Terminated at Amazon Elastic Load Balancer

In my last post, I described an ASP.NET Web Api RequireHttps attribute that supports SSL terminated at a load balancer like Amazon’s ELB.  Here’s a RequireHttps attribute for ASP.NET MVC with load balancer support:

using System;
using System.Configuration;
using System.Web.Mvc;
using System.Web;
using System.Collections.Generic;

namespace MvcHelpers
{
    public class RequireHttpsSupportsLBAttibute : RequireHttpsAttribute
    {
        public override void OnAuthorization(AuthorizationContext filterContext)
        {
            if (filterContext.HttpContext.Request.IsSecureConnectionConsideringLoadBalancer()) return;

            base.OnAuthorization(filterContext);
        }
    }

    public static class HttpRequestBaseHelper
    {
        public static bool IsSecureConnectionConsideringLoadBalancer(this HttpRequestBase request)
        {
            return request.IsSecureConnection || LoadBalancerSecured(request);
        }

        public static bool LoadBalancerSecured(HttpRequestBase request)
        {
            if (string.Equals(request.Headers["X-Forwarded-Proto"],
                "https"
                StringComparison.InvariantCultureIgnoreCase))
            {
                return true;
            }

            return false;
        }
    }
}