/// <summary>
/// Intercepts the beginning of the request pipeline. This will detect SingleSignOut
/// requests. SingleSignOut requests are posted back to the serviceName URL that
/// was passed when the CAS session was established. Since the behavior of the script
/// at that URL is unknown, a POST back by the CAS server could have unexpected
/// consequences. We want to prevent this request from authenticating and from
/// executing the HttpHandler typically associated with that URL. So we are handling
/// this by sending back an HTTP 200 (OK) message with a blank body and short
/// circuiting all event processing and firing EndRequest directly
/// (via CompleteRequest()).
/// </summary>
/// <param name="sender">The HttpApplication that sent the request</param>
/// <param name="e">Not used</param>
private static void OnBeginRequest(object sender, EventArgs e)
{
// Validate the ticket coming back from the CAS server (NETC-55)
if (!RequestEvaluator.GetRequestIsAppropriateForCasAuthentication())
{
logger.Debug("BeginRequest bypassed for " + HttpContext.Current.Request.RawUrl);
return;
}
CasAuthentication.Initialize();
HttpContext context = HttpContext.Current;
HttpRequest request = context.Request;
logger.Debug("Starting BeginRequest for " + request.RawUrl);
// Cleanup expired ServiceTickets in the ServiceTicketManager
if (CasAuthentication.ServiceTicketManager != null)
{
CasAuthentication.ServiceTicketManager.RemoveExpiredTickets();
}
// Cleanup expired ProxyTicket mappings in the ProxyTicketManager
if (CasAuthentication.ProxyTicketManager != null)
{
CasAuthentication.ProxyTicketManager.RemoveExpiredMappings();
}
// Detect & process inbound Single SignOut Requests from the CAS server
if (CasAuthentication.ServiceTicketManager != null && CasAuthentication.ProcessIncomingSingleSignOutRequests && RequestEvaluator.GetRequestIsCasSingleSignOut())
{
logger.Info("Processing inbound Single Sign Out request.");
CasAuthentication.ProcessSingleSignOutRequest();
return;
}
// Detect & process inbound proxy callback verifications from the CAS server
if (CasAuthentication.ProxyTicketManager != null && RequestEvaluator.GetRequestIsProxyResponse())
{
logger.Info("Processing Proxy Callback request");
CasAuthentication.ProcessProxyCallbackRequest();
return;
}
logger.Debug("Ending BeginRequest for " + request.RawUrl);
}