Server variable HTTP_CLUSTER_HTTPS

 public virtual bool IsCurrentConnectionSecured()
        {
            bool useSsl = false;
            if (IsRequestAvailable(_httpContext))
            {
                //when your hosting uses a load balancer on their server then the Request.IsSecureConnection is never got set to true

                //1. use HTTP_CLUSTER_HTTPS?
                if (!string.IsNullOrEmpty(ConfigurationManager.AppSettings["Use_HTTP_CLUSTER_HTTPS"]) &&
                   Convert.ToBoolean(ConfigurationManager.AppSettings["Use_HTTP_CLUSTER_HTTPS"]))
                {
                    useSsl = ServerVariables("HTTP_CLUSTER_HTTPS") == "on";
                }
                //2. use HTTP_X_FORWARDED_PROTO?
                else if (!string.IsNullOrEmpty(ConfigurationManager.AppSettings["Use_HTTP_X_FORWARDED_PROTO"]) &&
                   Convert.ToBoolean(ConfigurationManager.AppSettings["Use_HTTP_X_FORWARDED_PROTO"]))
                {
                    useSsl = string.Equals(ServerVariables("HTTP_X_FORWARDED_PROTO"), "https", StringComparison.OrdinalIgnoreCase);
                }
                else
                {
                    useSsl = _httpContext.Request.IsSecureConnection;
                }
            }

            return useSsl;
        }