<?php
// https://calnetweb.berkeley.edu/calnet-technologists/cas/casifying-your-web-application-or-web-server/cas-code-samples/cas
$casService = 'https://servidor.com.br/cas-server';
$thisService = 'https://localhost' . $_SERVER['PHP_SELF'];
/*
* Check to see if there is a ticket in the GET request.
* CAS uses "ticket" for the service ticket. Bad choice of words, but
* it is what CAS uses.
*
* If the ticket exists, validate it with CAS. If not, redirect the user
* to CAS.
*
* Of course, you will want to hook this in with your application's
* session management system, i.e., if the user already has a session,
* you don't want to do either of these two things.
*
*/
if ($_SERVER["REQUEST_METHOD"] && $_GET["ticket"]) {
   if ($response = responseForTicket($_GET["ticket"])) {
      echo 'o email é '.$response;
   }
   else {
      echo "26-The response was not valid.".'<br>';
   }
}
else {
   header("Location: $casService/login?service=$thisService");
}
//* Returns the CAS response if the ticket is valid, and false if not.
function responseForTicket($ticket) {
   global $casService, $thisService;
   $casGet = "$casService/serviceValidate?ticket=$ticket&service=" . urlencode($thisService);
   $response = file_get_contents($casGet);
   if (preg_match('/cas:authenticationSuccess/', $response)) {
      return $response;
   }
   else {
      return false;
   }
}
?>