Q: How do I renew the timeout of my ApplicationCookie in Identity 2.0 Is there a way to renew the authentication timeout of a cookie as part of a particular web request?  I have an Angular app on top of my MVC 5 project and I need it to keep my server session alive in between requests.  I've got the Angular part working, but it appears that hitting a URL on my server is not sufficient to reset the Auth timeout.  I am new to Identity so I am probably missing something simple?
My Startup.Auth.cs code:
public void ConfigureAuth(IAppBuilder app)
    {
        // Configure the db context, user manager and signin manager to use a single instance per request
        app.CreatePerOwinContext(ApplicationDbContext.Create);
        app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
        app.CreatePerOwinContext<ApplicationSignInManager>(ApplicationSignInManager.Create);

        // Enable the application to use a cookie to store information for the signed in user
        app.UseCookieAuthentication(new CookieAuthenticationOptions
        {
            ExpireTimeSpan = TimeSpan.FromSeconds(30),
            AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
            LoginPath = new PathString("/Account/Login"),
            Provider = new CookieAuthenticationProvider
            {
                // Enables the application to validate the security stamp when the user logs in.
                // This is a security feature which is used when you change a password or add an external login to your account.  
                OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
                    validateInterval: TimeSpan.FromMinutes(20),
                    regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager))
            }
        });
    }

And my simple method (authorization is set up globally for all requests that do not have [AllowAnonymous]):
    [HttpGet]
    public HttpResponseMessage KeepAuthAlive()
    {
        // Renew Auth Cookie - how?
    }


A: Re-SignIn the User (this code assumes you have UserManager and SignInManager available as per the default Account controller and an async ActionResult). I haven't tested this, but it should hopefully work:
ApplicationUser user = await UserManager.FindByIdAsync(User.Identity.GetUserId());
if (user != null)
{
    await SignInManager.SignInAsync(user, isPersistent: false, rememberBrowser: false);
}

