public partial class Startup
{
    public void ConfigureAuth(IAppBuilder app)
    {
        app.UseCookieAuthentication(new CookieAuthenticationOptions
        {
            AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
            LoginPath = new PathString("/Account/Login"),
            SlidingExpiration = true,
            CookieSecure = CookieSecureOption.Never,
            ExpireTimeSpan = TimeSpan.FromMinutes(30)
        });

        AntiForgeryConfig.UniqueClaimTypeIdentifier = ClaimTypes.NameIdentifier;
    }
}

public ActionResult Login(LoginViewModel model, string returnUrl)
    {
        if (!ModelState.IsValid)
        {
            return View(model);
        }
        var isAuthenticated = false;

        using (var db = new DatabaseEntities())
        {
            var user = db.Users.FirstOrDefault(args => args.Username == model.Username);
            if (user == null)
            {
                ModelState.AddModelError("", "Username is not found");
                return View(model);
            }

            if (user.AuthenticationSource == 1)
            {
                isAuthenticated = LDAP.Authenticate(model.Username, model.Password);
            }
            else
            {
                if (user.Password == model.Password)
                {
                    if (user.IsLoggedIn == false)
                        isAuthenticated = true;
                    else if (user.IsLoggedIn == true)
                    {

                        ModelState.AddModelError("", "This user is logged in");
                        return View(model);
                    }
                }
            }

            if (isAuthenticated)
            {
                var claims = new List<Claim>();

                claims.Add(new Claim(ClaimTypes.NameIdentifier, user.Username));
                claims.Add(new Claim(ClaimTypes.Name, user.Username));
                claims.Add(new Claim("UserId", user.Id.ToString()));
                claims.Add(new Claim("DisplayName", user.DisplayName));

                var identity = new ClaimsIdentity(claims, DefaultAuthenticationTypes.ApplicationCookie);
                AuthenticationManager.SignIn(identity);

                user.LastLoginDate = DateTime.UtcNow;
                user.IsLoggedIn = true;

                db.SaveChanges();

                return RedirectToAction("Index", "Home");
            }

        }
        ModelState.AddModelError("", "Username or Password is invalid");
        return View(model);

    }

public ActionResult LogOff(string returnUrl)
    {
        using (var db = new DatabaseEntities())
        {
            var LoggedUsername = User.Identity.Name;
            var user = db.Users.FirstOrDefault(args => args.Username == LoggedUsername);
            user.IsLoggedIn = false;
            db.SaveChanges();
        }

        AuthenticationManager.SignOut(DefaultAuthenticationTypes.ApplicationCookie);
        return RedirectToAction("Login");
    }