public static FormsAuthenticationTicket RenewTicketIfOld(FormsAuthenticationTicket tOld)
{
if (tOld == null)
{
return(null);
}
DateTime now = DateTime.Now;
TimeSpan toIssue = now - tOld.IssueDate;
TimeSpan toExpiration = tOld.Expiration - now;
if (toExpiration > toIssue)
{
return(tOld);
}
FormsAuthenticationTicket tNew = tOld.Clone();
tNew.SetDates(now, now + (tOld.Expiration - tOld.IssueDate));
return(tNew);
}
