public void SignIn(User user, bool createPersistentCookie)
        {
            var accountEntry = new AccountEntry(user);

            var authTicket = new FormsAuthenticationTicket(1,
                                                           user.Login,
                                                           DateTime.Now,
                                                           DateTime.Now.AddMinutes(45),
                                                           createPersistentCookie,
                                                           accountEntry.Serialize());

            string encryptedTicket = FormsAuthentication.Encrypt(authTicket);

            var authCookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket)
                                 {
                                     Expires = DateTime.Now.Add(FormsAuthentication.Timeout),
                                 };

            HttpContext.Current.Response.Cookies.Add(authCookie);

            var identity = new CustomIdentity(accountEntry, authTicket.Name);

            HttpContext.Current.User = new GenericPrincipal(identity, identity.GetRoles());
        }