public class CheckLoginExpirationFilter : AuthorizeAttribute
{
    public override void OnAuthorization(AuthorizationContext filterContext)
    {
        base.OnAuthorization(filterContext);

        if (filterContext.Result is HttpUnauthorizedResult)
        {
            string returnUrl = null;
            if (filterContext.HttpContext.Request.HttpMethod.Equals("GET", StringComparison.CurrentCultureIgnoreCase))
                returnUrl = filterContext.HttpContext.Request.Url.GetComponents(UriComponents.PathAndQuery, UriFormat.SafeUnescaped);

            filterContext.Result = new RedirectToRouteResult(new RouteValueDictionary()
        {
            { "client", filterContext.RouteData.Values[ "client" ] },
            { "controller", "Security" },
            { "action", "Login" },
            { "ReturnUrl", returnUrl }
        });
        }
    }
}

public class Startup
{
    public void Configuration(IAppBuilder app)
    {
        app.UseCookieAuthentication(new CookieAuthenticationOptions
        {
            AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
            LoginPath = new PathString("/Security/Login"),
            CookieSecure = CookieSecureOption.SameAsRequest,
            SlidingExpiration = true,
            CookieName = "Program.Auth",
            ExpireTimeSpan = TimeSpan.FromSeconds(15)/*FromHours(1)*/,
            Provider = new CookieAuthenticationProvider { OnApplyRedirect = CustomRedirect }
        });

        // TODO - Figure out what claims type to base this on.
        AntiForgeryConfig.UniqueClaimTypeIdentifier = ClaimTypes.Email;
    }

    private static void CustomRedirect(CookieApplyRedirectContext context)
    {
        var redirectUrl = context.Options.LoginPath.ToString();
        if (context.Request.Method == WebRequestMethods.Http.Get)
        {
            var returnUrl = context.Request.Path.ToString();
            if (!string.IsNullOrEmpty(returnUrl) && !returnUrl.Equals("/"))
                redirectUrl += "?" + context.Options.ReturnUrlParameter + "=" + returnUrl;
        }
        else if (context.Request.Method == WebRequestMethods.Http.Post)
        {
            //TODO: add toastr message showing that the post did not succeed
        }
        context.Response.Redirect(redirectUrl + "?tbn=inactive");
    }
}