AuthCAS - Client library for CAS 2.0 authentication server


Version 1.4


AuthCAS aims at providing a Perl API to Yale's Central Authentication System (CAS). Only a basic Perl library is provided with CAS whereas AuthCAS is a full object-oriented library. =head1 PREREQUISITES

This script requires IO::Socket::SSL and LWP::UserAgent




  A simple example with a direct CAS authentication

  use AuthCAS;
  my $cas = new AuthCAS(casUrl => 'https://cas.myserver, 
                    CAFile => '/etc/httpd/conf/ssl.crt/ca-bundle.crt',

  my $login_url = $cas->getServerLoginURL('http://myserver/app.cgi');

  ## The user should be redirected to the $login_url
  ## When coming back from the CAS server a ticket is provided in the QUERY_STRING

  ## $ST should contain the receaved Service Ticket
  my $user = $cas->validateST('http://myserver/app.cgi', $ST);

  printf "User authenticated as %s\n", $user;

  In the following example a proxy is requesting a Proxy Ticket for the target application

  $cas->proxyMode(pgtFile => '/tmp/pgt.txt',
                  pgtCallbackUrl => 'https://myserver/proxy.cgi?callback=1
  ## Same as before but the URL is the proxy URL
  my $login_url = $cas->getServerLoginURL('http://myserver/proxy.cgi');

  ## Like in the previous example we should receave a $ST

  my $user = $cas->validateST('http://myserver/proxy.cgi', $ST);

  ## Process errors
  printf STDERR "Error: %s\n", &AuthCAS::get_errors() unless (defined $user);

  ## Now we request a Proxy Ticket for the target application
  my $PT = $cas->retrievePT('http://myserver/app.cgi');
  ## This piece of code is executed by the target application
  ## It received a Proxy Ticket from the proxy
  my ($user, @proxies) = $cas->validatePT('http://myserver/app.cgi', $PT);

  printf "User authenticated as %s via %s proxies\n", $user, join(',',@proxies);


CAS is Yale University's web authentication system, heavily inspired by Kerberos. Release 2.0 of CAS provides "proxied credential" feature that allows authentication tickets to be carried by intermediate applications (Portals for instance), they are called proxy.

This AuthCAS Perl module provides required subroutines to validate and retrieve CAS tickets.


Yale Central Authentication Service ( phpCAS (


Copyright (C) 2003 Comite Reseau des Universites ( All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.


Olivier Salaun