private string loginPostListener(LoginModel model)
        {
            try
            {
                var rublon = new Rublon2Factor(Globals.SystemToken, Globals.SecretKey);
                rublon.Language = "en";
                var url = rublon.Authorize(Globals.Host + "/Callback/Login/",
                                           model.UserName,
                                           model.UserName);

                if (!string.IsNullOrEmpty(url))
                {
                    WebSecurity.Logout();
                    Session["login_user"] = model.UserName;
                    Session["login_pwd"] = model.Password;
                    return url;
                }
            }
            catch (Exception)
            {
                WebSecurity.Logout();
                throw;
            }

            return string.Empty;
        }
        public ActionResult Login(LoginModel model, string returnUrl)
        {
            if (ModelState.IsValid && WebSecurity.Login(model.UserName, model.Password, persistCookie: model.RememberMe))
            {
                try
                {
                    var url = loginPostListener(model);
                    if (!string.IsNullOrEmpty(url))
                    {
                        return Redirect(url);
                    }

                    return Redirect(returnUrl);
                }
                catch
                {
                    ModelState.AddModelError("", "Rublon authentication failed.");
                    return View(model);
                }
            }

            // If we got this far, something failed, redisplay form
            ModelState.AddModelError("", "The user name or password provided is incorrect.");
            return View(model);
        }