Problem creating persistent authentication cookie: ASP.NET MVC - asp.net

Question

OK, here's my code to create an authentication cookie:
// get user's role
List<UserType> roles = rc.rolesRepository.GetUserRoles(rc.userLoginRepository.GetUserID(userName));
List<string> rolesList = (from r in roles
select r.ToString()).ToList();
string[] rolesArr = rolesList.ToArray();
// create encryption cookie
FormsAuthenticationTicket authTicket = new FormsAuthenticationTicket(
1,
userName,
DateTime.Now,
DateTime.Now.AddDays(90),
createPersistentCookie,
String.Join(";",rolesArr) //user's roles
);
// add cookie to response stream
string encryptedTicket = FormsAuthentication.Encrypt(authTicket);
System.Web.HttpCookie authCookie = new System.Web.HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket);
System.Web.HttpContext.Current.Response.Cookies.Add(authCookie);
//FormsAuthentication.SetAuthCookie(userName, createPersistentCookie);
And here's my code in Global.asax to set the user roles into the user identity:
protected void Application_AuthenticateRequest(Object sender, EventArgs e)
{
HttpCookie authCookie = Context.Request.Cookies[FormsAuthentication.FormsCookieName];
if (authCookie == null || authCookie.Value == "")
{
return;
}
FormsAuthenticationTicket authTicket = null;
try
{
authTicket = FormsAuthentication.Decrypt(authCookie.Value);
string[] roles = authTicket.UserData.Split(new char[] { ';' });
if (Context.User != null)
{
Context.User = new System.Security.Principal.GenericPrincipal(Context.User.Identity, roles);
}
}
catch
{
return;
}
}
However, if "createPersistentCookie" is TRUE in the top example, no persistent cookie is created. If I uncomment the last line like so:
//System.Web.HttpContext.Current.Response.Cookies.Add(authCookie);
FormsAuthentication.SetAuthCookie(userName, createPersistentCookie);
then the persistent cookie is created on my hard drive. BUT then in the Global.asax code, the UserData field in "authTicket" is blank, so I can't set up the roles properly!
So I have to use SetAuthCookie to create a persistent cookie, but then for some reason the UserData field disappears from the persistent cookie.
What is the answer to this??

Answer 1

To create a persistent cookie you need to set the Expires property:
if (authTicket.IsPersistent)
{
authCookie.Expires = authTicket.Expiration;
}