SimpleCAS dir for cas_auth_unl

plugins/cas_auth_unl/SimpleCAS.php

+<?php
+/**
+ * This is a CAS client authentication library for PHP 5.
+ * 
+ * <code>
+ * <?php
+ * $protocol = new SimpleCAS_Protocol_Version2('login.unl.edu', 443, 'cas');
+ * $client = SimpleCAS::client($protocol);
+ * $client->forceAuthentication();
+ * 
+ * if (isset($_GET['logout'])) {
+ *     $client->logout();
+ * }
+ * 
+ * if ($client->isAuthenticated()) {
+ *     echo '<h1>Authentication Successful!</h1>';
+ *     echo '<p>The user\'s login is '.$client->getUsername().'</p>';
+ *     echo '<a href="?logout">Logout</a>';
+ * }
+ * </code>
+ * 
+ * PHP version 5
+ * 
+ * @category  Authentication 
+ * @package   SimpleCAS
+ * @author    Brett Bieber <brett.bieber@gmail.com>
+ * @copyright 2008 Regents of the University of Nebraska
+ * @license   http://www1.unl.edu/wdn/wiki/Software_License BSD License
+ * @link      http://code.google.com/p/simplecas/
+ */
+class SimpleCAS
+{
+    /**
+     * Version of the CAS library.
+     */
+    const VERSION = '0.0.1';
+    
+    /**
+     * Singleton CAS object
+     *
+     * @var CAS
+     */
+    static private $_instance;
+    
+    /**
+     * Is user authenticated?
+     *
+     * @var bool
+     */
+    private $_authenticated = false;
+    
+    /**
+     * Protocol for the server running the CAS service.
+     *
+     * @var SimpleCAS_Protocol
+     */
+    protected $protocol;
+    
+    /**
+     * User's login name if authenticated.
+     *
+     * @var string
+     */
+    protected $username;
+
+    /**
+     * (Optional) alternative service URL to return to after CAS authentication.
+     *
+     * @var string
+     */
+	static protected $url;
+    
+    /**
+     * Construct a CAS client object.
+     *
+     * @param SimpleCAS_Protocol $protocol Protocol to use for authentication.
+     */
+    private function __construct(SimpleCAS_Protocol $protocol)
+    {
+        $this->protocol = $protocol;
+        
+        if ($this->protocol instanceof SimpleCAS_SingleSignOut
+            && isset($_POST)) {
+            if ($ticket = $this->protocol->validateLogoutRequest($_POST)) {
+                $this->logout($ticket);
+            }
+        }
+        
+        if (session_id() == '') {
+            session_start();
+        }
+        
+        if (isset($_SESSION['__SIMPLECAS_TICKET'])) {
+            $this->_authenticated = true;
+        }
+		
+        
+        if ($this->_authenticated == false
+            && isset($_GET['ticket'])) {
+            $this->validateTicket($_GET['ticket']);
+        }
+    }
+    
+    /**
+     * Checks a ticket to see if it is valid.
+     * 
+     * If the CAS server verifies the ticket, a session is created and the user
+     * is marked as authenticated.
+     *
+     * @param string $ticket Ticket from the CAS Server
+     * 
+     * @return bool
+     */
+    protected function validateTicket($ticket)
+    {
+        if ($uid = $this->protocol->validateTicket($ticket, self::getURL())) {
+            $this->setAuthenticated($uid);
+            $this->redirect(self::getURL());
+            return true;
+        } else {
+            return false;
+        }
+    }
+    
+    /**
+     * Marks the current session as authenticated.
+     *
+     * @param string $uid User name returned by the CAS server.
+     * 
+     * @return void
+     */
+    protected function setAuthenticated($uid)
+    {
+        $_SESSION['__SIMPLECAS_TICKET'] = true;
+        $_SESSION['__SIMPLECAS_UID']    = $uid;
+        $this->_authenticated           = true;
+    }
+    
+    /**
+     * Return the authenticated user's login name.
+     *
+     * @return string
+     */
+    public function getUsername()
+    {
+        return $_SESSION['__SIMPLECAS_UID'];
+    }
+    
+    /**
+     * Singleton interface, returns CAS object.
+     * 
+     * @param CAS_Server $server CAS Server object
+     * 
+     * @return CAS
+     */
+    static public function client(SimpleCAS_Protocol $protocol)
+    {
+        if (!isset(self::$_instance)) {
+            self::$_instance = new self($protocol);
+        }
+        
+        return self::$_instance;
+    }
+    
+    /**
+     * If client is not authenticated, this will redirecting to login and exit.
+     * 
+     * Otherwise, return the CAS object.
+     *
+     * @return CAS
+     */
+    function forceAuthentication()
+    {
+        if (!$this->isAuthenticated()) {
+            self::redirect($this->protocol->getLoginURL(self::getURL()));
+        }
+        return $this;
+    }
+    
+    /**
+     * Check if this user has been authenticated or not.
+     * 
+     * @return bool
+     */
+    function isAuthenticated()
+    {
+        return $this->_authenticated;
+    }
+    
+    /**
+     * Destroys session data for this client, redirects to the server logout
+     * url.
+     * 
+     * @param string $url URL to provide the client on logout.
+     * 
+     * @return void
+     */
+    public function logout($url = '')
+    {
+        session_destroy();
+        if (empty($url)) {
+            $url = self::getURL();
+        }
+        $this->redirect($this->protocol->getLogoutURL($url));
+    }
+    
+    /**
+     * Returns the current URL without CAS affecting parameters.
+     * 
+     * @return string url
+     */
+    static public function getURL()
+    {
+		if (!empty(self::$url)) {
+			return self::$url;
+		}
+        if (isset($_SERVER['HTTPS'])
+            && !empty($_SERVER['HTTPS'])
+            && $_SERVER['HTTPS'] == 'on') {
+            $protocol = 'https';
+        } else {
+            $protocol = 'http';
+        }
+    
+        $url = $protocol.'://'.$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
+        
+        $replacements = array('/\?logout/'        => '',
+                              '/&ticket=[^&]*/'   => '',
+                              '/\?ticket=[^&;]*/' => '?',
+                              '/\?%26/'           => '?',
+                              '/\?&/'             => '?',
+                              '/\?$/'             => '');
+        
+        $url = preg_replace(array_keys($replacements),
+                            array_values($replacements), $url);
+        
+        return $url;
+    }
+	
+   /**
+    * Set an alternative return URL
+    * 
+    * @param string $url alternative return URL
+    * 
+    * @return void
+    */ 
+	public static function setURL($url)
+	{
+		self::$url = $url; 
+	}
+    
+    /**
+     * Send a header to redirect the client to another URL.
+     *
+     * @param string $url URL to redirect the client to.
+     * 
+     * @return void
+     */
+    public static function redirect($url)
+    {
+        header("Location: $url");
+        exit();
+    }
+    
+    /**
+     * Get the version of the CAS library
+     *
+     * @return string
+     */
+    static public function getVersion()
+    {
+        return self::VERSION;
+    }
+}