<?php

/*
 * Copyright © 2003-2010, The ESUP-Portail consortium & the JA-SIG Collaborative.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright notice,
 *       this list of conditions and the following disclaimer in the documentation
 *       and/or other materials provided with the distribution.
 *     * Neither the name of the ESUP-Portail consortium & the JA-SIG
 *       Collaborative nor the names of its contributors may be used to endorse or
 *       promote products derived from this software without specific prior
 *       written permission.

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file CAS/client.php
 * Main class of the phpCAS library
 */

// include internationalization stuff
include_once(dirname(__FILE__).'/languages/languages.php');

// include PGT storage classes
include_once(dirname(__FILE__).'/PGTStorage/pgt-main.php');

/**
 * @class CASClient
 * The CASClient class is a client interface that provides CAS authentication
 * to PHP applications.
 *
 * @author Pascal Aubry <pascal.aubry at univ-rennes1.fr>
 */

class CASClient
{
	
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	// XX                                                                    XX
	// XX                          CONFIGURATION                             XX
	// XX                                                                    XX
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	
	// ########################################################################
	//  HTML OUTPUT
	// ########################################################################
	/**
	 * @addtogroup internalOutput
	 * @{
	 */  
	
	/**
	 * This method filters a string by replacing special tokens by appropriate values
	 * and prints it. The corresponding tokens are taken into account:
	 * - __CAS_VERSION__
	 * - __PHPCAS_VERSION__
	 * - __SERVER_BASE_URL__
	 *
	 * Used by CASClient::PrintHTMLHeader() and CASClient::printHTMLFooter().
	 *
	 * @param $str the string to filter and output
	 *
	 * @private
	 */
	function HTMLFilterOutput($str)
		{
		$str = str_replace('__CAS_VERSION__',$this->getServerVersion(),$str);
		$str = str_replace('__PHPCAS_VERSION__',phpCAS::getVersion(),$str);
		$str = str_replace('__SERVER_BASE_URL__',$this->getServerBaseURL(),$str);
		echo $str;
		}
	
	/**
	 * A string used to print the header of HTML pages. Written by CASClient::setHTMLHeader(),
	 * read by CASClient::printHTMLHeader().
	 *
	 * @hideinitializer
	 * @private
	 * @see CASClient::setHTMLHeader, CASClient::printHTMLHeader()
	 */
	var $_output_header = '';
	
	/**
	 * This method prints the header of the HTML output (after filtering). If
	 * CASClient::setHTMLHeader() was not used, a default header is output.
	 *
	 * @param $title the title of the page
	 *
	 * @see HTMLFilterOutput()
	 * @private
	 */
	function printHTMLHeader($title)
		{
		$this->HTMLFilterOutput(str_replace('__TITLE__',
			$title,
			(empty($this->_output_header)
					? '<html><head><title>__TITLE__</title></head><body><h1>__TITLE__</h1>'
							: $this->_output_header)
		)
		);
		}
	
	/**
	 * A string used to print the footer of HTML pages. Written by CASClient::setHTMLFooter(),
	 * read by printHTMLFooter().
	 *
	 * @hideinitializer
	 * @private
	 * @see CASClient::setHTMLFooter, CASClient::printHTMLFooter()
	 */
	var $_output_footer = '';
	
	/**
	 * This method prints the footer of the HTML output (after filtering). If
	 * CASClient::setHTMLFooter() was not used, a default footer is output.
	 *
	 * @see HTMLFilterOutput()
	 * @private
	 */
	function printHTMLFooter()
		{
		$this->HTMLFilterOutput(empty($this->_output_footer)
			?('<hr><address>phpCAS __PHPCAS_VERSION__ '.$this->getString(CAS_STR_USING_SERVER).' <a href="__SERVER_BASE_URL__">__SERVER_BASE_URL__</a> (CAS __CAS_VERSION__)</a></address></body></html>')
					:$this->_output_footer);
		}
	
	/**
	 * This method set the HTML header used for all outputs.
	 *
	 * @param $header the HTML header.
	 *
	 * @public
	 */
	function setHTMLHeader($header)
		{
		$this->_output_header = $header;
		}
	
	/**
	 * This method set the HTML footer used for all outputs.
	 *
	 * @param $footer the HTML footer.
	 *
	 * @public
	 */
	function setHTMLFooter($footer)
		{
		$this->_output_footer = $footer;
		}
	
	/** @} */
	// ########################################################################
	//  INTERNATIONALIZATION
	// ########################################################################
	/**
	 * @addtogroup internalLang
	 * @{
	 */  
	/**
	 * A string corresponding to the language used by phpCAS. Written by 
	 * CASClient::setLang(), read by CASClient::getLang().
	 
	 * @note debugging information is always in english (debug purposes only).
	 *
	 * @hideinitializer
	 * @private
	 * @sa CASClient::_strings, CASClient::getString()
	 */
	var $_lang = '';
	
	/**
	 * This method returns the language used by phpCAS.
	 *
	 * @return a string representing the language
	 *
	 * @private
	 */
	function getLang()
		{
		if ( empty($this->_lang) )
			$this->setLang(PHPCAS_LANG_DEFAULT);
		return $this->_lang;
		}
	
	/**
	 * array containing the strings used by phpCAS. Written by CASClient::setLang(), read by 
	 * CASClient::getString() and used by CASClient::setLang().
	 *
	 * @note This array is filled by instructions in CAS/languages/<$this->_lang>.php
	 *
	 * @private
	 * @see CASClient::_lang, CASClient::getString(), CASClient::setLang(), CASClient::getLang()
	 */
	var $_strings;
	
	/**
	 * This method returns a string depending on the language.
	 *
	 * @param $str the index of the string in $_string.
	 *
	 * @return the string corresponding to $index in $string.
	 *
	 * @private
	 */
	function getString($str)
		{
		// call CASclient::getLang() to be sure the language is initialized
		$this->getLang();
		
		if ( !isset($this->_strings[$str]) ) {
			trigger_error('string `'.$str.'\' not defined for language `'.$this->getLang().'\'',E_USER_ERROR);
		}
		return $this->_strings[$str];
		}
	
	/**
	 * This method is used to set the language used by phpCAS. 
	 * @note Can be called only once.
	 *
	 * @param $lang a string representing the language.
	 *
	 * @public
	 * @sa CAS_LANG_FRENCH, CAS_LANG_ENGLISH
	 */
	function setLang($lang)
		{
		// include the corresponding language file
		include_once(dirname(__FILE__).'/languages/'.$lang.'.php');
		
		if ( !is_array($this->_strings) ) {
			trigger_error('language `'.$lang.'\' is not implemented',E_USER_ERROR);
		}
		$this->_lang = $lang;
		}
	
	/** @} */
	// ########################################################################
	//  CAS SERVER CONFIG
	// ########################################################################
	/**
	 * @addtogroup internalConfig
	 * @{
	 */  
	
	/**
	 * a record to store information about the CAS server.
	 * - $_server["version"]: the version of the CAS server
	 * - $_server["hostname"]: the hostname of the CAS server
	 * - $_server["port"]: the port the CAS server is running on
	 * - $_server["uri"]: the base URI the CAS server is responding on
	 * - $_server["base_url"]: the base URL of the CAS server
	 * - $_server["login_url"]: the login URL of the CAS server
	 * - $_server["service_validate_url"]: the service validating URL of the CAS server
	 * - $_server["proxy_url"]: the proxy URL of the CAS server
	 * - $_server["proxy_validate_url"]: the proxy validating URL of the CAS server
	 * - $_server["logout_url"]: the logout URL of the CAS server
	 *
	 * $_server["version"], $_server["hostname"], $_server["port"] and $_server["uri"]
	 * are written by CASClient::CASClient(), read by CASClient::getServerVersion(), 
	 * CASClient::getServerHostname(), CASClient::getServerPort() and CASClient::getServerURI().
	 *
	 * The other fields are written and read by CASClient::getServerBaseURL(), 
	 * CASClient::getServerLoginURL(), CASClient::getServerServiceValidateURL(), 
	 * CASClient::getServerProxyValidateURL() and CASClient::getServerLogoutURL().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_server = array(
		'version' => -1,
		'hostname' => 'none',
		'port' => -1,
		'uri' => 'none'
	);
	
	/**
	 * This method is used to retrieve the version of the CAS server.
	 * @return the version of the CAS server.
	 * @private
	 */
	function getServerVersion()
		{ 
		return $this->_server['version']; 
		}
	
	/**
	 * This method is used to retrieve the hostname of the CAS server.
	 * @return the hostname of the CAS server.
	 * @private
	 */
	function getServerHostname()
		{ return $this->_server['hostname']; }
	
	/**
	 * This method is used to retrieve the port of the CAS server.
	 * @return the port of the CAS server.
	 * @private
	 */
	function getServerPort()
		{ return $this->_server['port']; }
	
	/**
	 * This method is used to retrieve the URI of the CAS server.
	 * @return a URI.
	 * @private
	 */
	function getServerURI()
		{ return $this->_server['uri']; }
	
	/**
	 * This method is used to retrieve the base URL of the CAS server.
	 * @return a URL.
	 * @private
	 */
	function getServerBaseURL()
		{ 
		// the URL is build only when needed
		if ( empty($this->_server['base_url']) ) {
			$this->_server['base_url'] = 'https://'
				.$this->getServerHostname()
				.':'
				.$this->getServerPort()
				.$this->getServerURI();
		}
		return $this->_server['base_url']; 
		}
	
	/**
	 * This method is used to retrieve the login URL of the CAS server.
	 * @param $gateway true to check authentication, false to force it
	 * @param $renew true to force the authentication with the CAS server
	 * NOTE : It is recommended that CAS implementations ignore the
	 "gateway" parameter if "renew" is set
	 * @return a URL.
	 * @private
	 */
	function getServerLoginURL($gateway=false,$renew=false) {
		phpCAS::traceBegin();
		// the URL is build only when needed
		if ( empty($this->_server['login_url']) ) {
			$this->_server['login_url'] = $this->getServerBaseURL();
			$this->_server['login_url'] .= 'login?service=';
			// $this->_server['login_url'] .= preg_replace('/&/','%26',$this->getURL());
			$this->_server['login_url'] .= urlencode($this->getURL());
			if($renew) {
				// It is recommended that when the "renew" parameter is set, its value be "true"
				$this->_server['login_url'] .= '&renew=true';
			} elseif ($gateway) {
				// It is recommended that when the "gateway" parameter is set, its value be "true"
				$this->_server['login_url'] .= '&gateway=true';
			}
		}
		phpCAS::traceEnd($this->_server['login_url']);
		return $this->_server['login_url'];
	} 
	
	/**
	 * This method sets the login URL of the CAS server.
	 * @param $url the login URL
	 * @private
	 * @since 0.4.21 by Wyman Chan
	 */
	function setServerLoginURL($url)
		{
		return $this->_server['login_url'] = $url;
		}
	
	
	/**
	 * This method sets the serviceValidate URL of the CAS server.
	 * @param $url the serviceValidate URL
	 * @private
	 * @since 1.1.0 by Joachim Fritschi
	 */
	function setServerServiceValidateURL($url)
		{
		return $this->_server['service_validate_url'] = $url;
		}
	
	
	/**
	 * This method sets the proxyValidate URL of the CAS server.
	 * @param $url the proxyValidate URL
	 * @private
	 * @since 1.1.0 by Joachim Fritschi
	 */
	function setServerProxyValidateURL($url)
		{
		return $this->_server['proxy_validate_url'] = $url;
		}
	
	
	/**
	 * This method sets the samlValidate URL of the CAS server.
	 * @param $url the samlValidate URL
	 * @private
	 * @since 1.1.0 by Joachim Fritschi
	 */
	function setServerSamlValidateURL($url)
		{
		return $this->_server['saml_validate_url'] = $url;
		}
	
	
	/**
	 * This method is used to retrieve the service validating URL of the CAS server.
	 * @return a URL.
	 * @private
	 */
	function getServerServiceValidateURL()
		{ 
		// the URL is build only when needed
		if ( empty($this->_server['service_validate_url']) ) {
			switch ($this->getServerVersion()) {
				case CAS_VERSION_1_0:
					$this->_server['service_validate_url'] = $this->getServerBaseURL().'validate';
					break;
				case CAS_VERSION_2_0:
					$this->_server['service_validate_url'] = $this->getServerBaseURL().'serviceValidate';
					break;
			}
		}
		//      return $this->_server['service_validate_url'].'?service='.preg_replace('/&/','%26',$this->getURL()); 
		return $this->_server['service_validate_url'].'?service='.urlencode($this->getURL()); 
		}
	/**
	 * This method is used to retrieve the SAML validating URL of the CAS server.
	 * @return a URL.
	 * @private
	 */
	function getServerSamlValidateURL()
		{
		phpCAS::traceBegin();
		// the URL is build only when needed
		if ( empty($this->_server['saml_validate_url']) ) {
			switch ($this->getServerVersion()) {
				case SAML_VERSION_1_1:
					$this->_server['saml_validate_url'] = $this->getServerBaseURL().'samlValidate';
					break;
			}
		}
		phpCAS::traceEnd($this->_server['saml_validate_url'].'?TARGET='.urlencode($this->getURL()));
		return $this->_server['saml_validate_url'].'?TARGET='.urlencode($this->getURL());
		}
	/**
	 * This method is used to retrieve the proxy validating URL of the CAS server.
	 * @return a URL.
	 * @private
	 */
	function getServerProxyValidateURL()
		{ 
		// the URL is build only when needed
		if ( empty($this->_server['proxy_validate_url']) ) {
			switch ($this->getServerVersion()) {
				case CAS_VERSION_1_0:
					$this->_server['proxy_validate_url'] = '';
					break;
				case CAS_VERSION_2_0:
					$this->_server['proxy_validate_url'] = $this->getServerBaseURL().'proxyValidate';
					break;
			}
		}
		//      return $this->_server['proxy_validate_url'].'?service='.preg_replace('/&/','%26',$this->getURL()); 
		return $this->_server['proxy_validate_url'].'?service='.urlencode($this->getURL()); 
		}
	
	/**
	 * This method is used to retrieve the proxy URL of the CAS server.
	 * @return a URL.
	 * @private
	 */
	function getServerProxyURL()
		{ 
		// the URL is build only when needed
		if ( empty($this->_server['proxy_url']) ) {
			switch ($this->getServerVersion()) {
				case CAS_VERSION_1_0:
					$this->_server['proxy_url'] = '';
					break;
				case CAS_VERSION_2_0:
					$this->_server['proxy_url'] = $this->getServerBaseURL().'proxy';
					break;
			}
		}
		return $this->_server['proxy_url']; 
		}
	
	/**
	 * This method is used to retrieve the logout URL of the CAS server.
	 * @return a URL.
	 * @private
	 */
	function getServerLogoutURL()
		{ 
		// the URL is build only when needed
		if ( empty($this->_server['logout_url']) ) {
			$this->_server['logout_url'] = $this->getServerBaseURL().'logout';
		}
		return $this->_server['logout_url']; 
		}
	
	/**
	 * This method sets the logout URL of the CAS server.
	 * @param $url the logout URL
	 * @private
	 * @since 0.4.21 by Wyman Chan
	 */
	function setServerLogoutURL($url)
		{
		return $this->_server['logout_url'] = $url;
		}
	
	/**
	 * An array to store extra curl options.
	 */	
	var $_curl_options = array();
	
	/**
	 * This method is used to set additional user curl options.
	 */
	function setExtraCurlOption($key, $value)
		{
		$this->_curl_options[$key] = $value;
		}
	
	/**
	 * This method checks to see if the request is secured via HTTPS
	 * @return true if https, false otherwise
	 * @private
	 */
	function isHttps() {
		//if ( isset($_SERVER['HTTPS']) && !empty($_SERVER['HTTPS']) ) {
		//0.4.24 by Hinnack
		if ( isset($_SERVER['HTTPS']) && !empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') {
			return true;
		} else {
			return false;
		}
	}
	
	// ########################################################################
	//  CONSTRUCTOR
	// ########################################################################
	/**
	 * CASClient constructor.
	 *
	 * @param $server_version the version of the CAS server
	 * @param $proxy TRUE if the CAS client is a CAS proxy, FALSE otherwise
	 * @param $server_hostname the hostname of the CAS server
	 * @param $server_port the port the CAS server is running on
	 * @param $server_uri the URI the CAS server is responding on
	 * @param $start_session Have phpCAS start PHP sessions (default true)
	 *
	 * @return a newly created CASClient object
	 *
	 * @public
	 */
	function CASClient(
					   $server_version,
					   $proxy,
					   $server_hostname,
					   $server_port,
					   $server_uri,
					   $start_session = true) {
		
		phpCAS::traceBegin();
		
		// the redirect header() call and DOM parsing code from domxml-php4-php5.php won't work in PHP4 compatibility mode
		if (version_compare(PHP_VERSION,'5','>=') && ini_get('zend.ze1_compatibility_mode')) {
			phpCAS::error('phpCAS cannot support zend.ze1_compatibility_mode. Sorry.');
		}
		// skip Session Handling for logout requests and if don't want it'
		if ($start_session && !$this->isLogoutRequest()) {
			phpCAS::trace("Starting session handling");
			// Check for Tickets from the CAS server
			if (empty($_GET['ticket'])){
				phpCAS::trace("No ticket found");
				// only create a session if necessary
				if (!session_id()) {
					phpCAS::trace("No session found, creating new session");
					session_start();
				}
			}else{
				phpCAS::trace("Ticket found");
				// We have to copy any old data before renaming the session
				if (session_id()) {
					phpCAS::trace("Old active session found, saving old data and destroying session");
					$old_session = $_SESSION;
					session_destroy();	
				}else{
					session_start();
					phpCAS::trace("Starting possible old session to copy variables");
					$old_session = $_SESSION;
					session_destroy();	
				}
				// set up a new session, of name based on the ticket
				$session_id = preg_replace('/[^\w]/','',$_GET['ticket']);
				phpCAS::LOG("Session ID: " . $session_id);
				session_id($session_id);
				session_start();
				// restore old session vars
				if(isset($old_session)){
					phpCAS::trace("Restoring old session vars");
					$_SESSION = $old_session;
				}
			}
		}else{
			phpCAS::trace("Skipping session creation");
		}
		
		
		// are we in proxy mode ?
		$this->_proxy = $proxy;
		
		//check version
		switch ($server_version) {
			case CAS_VERSION_1_0:
				if ( $this->isProxy() )
					phpCAS::error('CAS proxies are not supported in CAS '
						.$server_version);
				break;
			case CAS_VERSION_2_0:
				break;
			case SAML_VERSION_1_1:
				break;
			default:
				phpCAS::error('this version of CAS (`'
					.$server_version
					.'\') is not supported by phpCAS '
					.phpCAS::getVersion());
		}
		$this->_server['version'] = $server_version;
		
		// check hostname
		if ( empty($server_hostname) 
				|| !preg_match('/[\.\d\-abcdefghijklmnopqrstuvwxyz]*/',$server_hostname) ) {
			phpCAS::error('bad CAS server hostname (`'.$server_hostname.'\')');
		}
		$this->_server['hostname'] = $server_hostname;
		
		// check port
		if ( $server_port == 0 
			|| !is_int($server_port) ) {
			phpCAS::error('bad CAS server port (`'.$server_hostname.'\')');
		}
		$this->_server['port'] = $server_port;
		
		// check URI
		if ( !preg_match('/[\.\d\-_abcdefghijklmnopqrstuvwxyz\/]*/',$server_uri) ) {
			phpCAS::error('bad CAS server URI (`'.$server_uri.'\')');
		}
		// add leading and trailing `/' and remove doubles      
		$server_uri = preg_replace('/\/\//','/','/'.$server_uri.'/');
		$this->_server['uri'] = $server_uri;
		
		// set to callback mode if PgtIou and PgtId CGI GET parameters are provided 
		if ( $this->isProxy() ) {
			$this->setCallbackMode(!empty($_GET['pgtIou'])&&!empty($_GET['pgtId']));
		}
		
		if ( $this->isCallbackMode() ) {
			//callback mode: check that phpCAS is secured
			if ( !$this->isHttps() ) {
				phpCAS::error('CAS proxies must be secured to use phpCAS; PGT\'s will not be received from the CAS server');
			}
		} else {
			//normal mode: get ticket and remove it from CGI parameters for developpers
			$ticket = (isset($_GET['ticket']) ? $_GET['ticket'] : null);
			switch ($this->getServerVersion()) {
				case CAS_VERSION_1_0: // check for a Service Ticket
					if( preg_match('/^ST-/',$ticket) ) {
						phpCAS::trace('ST \''.$ticket.'\' found');
						//ST present
						$this->setST($ticket);
						//ticket has been taken into account, unset it to hide it to applications
						unset($_GET['ticket']);
					} else if ( !empty($ticket) ) {
						//ill-formed ticket, halt
						phpCAS::error('ill-formed ticket found in the URL (ticket=`'.htmlentities($ticket).'\')');
					}
					break;
				case CAS_VERSION_2_0: // check for a Service or Proxy Ticket
					if( preg_match('/^[SP]T-/',$ticket) ) {
						phpCAS::trace('ST or PT \''.$ticket.'\' found');
						$this->setPT($ticket);
						unset($_GET['ticket']);
					} else if ( !empty($ticket) ) {
						//ill-formed ticket, halt
						phpCAS::error('ill-formed ticket found in the URL (ticket=`'.htmlentities($ticket).'\')');
					} 
					break;
				case SAML_VERSION_1_1: // SAML just does Service Tickets
					if( preg_match('/^[SP]T-/',$ticket) ) {
						phpCAS::trace('SA \''.$ticket.'\' found');
						$this->setSA($ticket);
						unset($_GET['ticket']);
					} else if ( !empty($ticket) ) {
						//ill-formed ticket, halt
						phpCAS::error('ill-formed ticket found in the URL (ticket=`'.htmlentities($ticket).'\')');
					}
					break;
			}
		}
		phpCAS::traceEnd();
	}
	
	/** @} */
	
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	// XX                                                                    XX
	// XX                           AUTHENTICATION                           XX
	// XX                                                                    XX
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	
	/**
	 * @addtogroup internalAuthentication
	 * @{
	 */  
	
	/**
	 * The Authenticated user. Written by CASClient::setUser(), read by CASClient::getUser().
	 * @attention client applications should use phpCAS::getUser().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_user = '';
	
	/**
	 * This method sets the CAS user's login name.
	 *
	 * @param $user the login name of the authenticated user.
	 *
	 * @private
	 */
	function setUser($user)
		{
		$this->_user = $user;
		}
	
	/**
	 * This method returns the CAS user's login name.
	 * @warning should be called only after CASClient::forceAuthentication() or 
	 * CASClient::isAuthenticated(), otherwise halt with an error.
	 *
	 * @return the login name of the authenticated user
	 */
	function getUser()
		{
		if ( empty($this->_user) ) {
			phpCAS::error('this method should be used only after '.__CLASS__.'::forceAuthentication() or '.__CLASS__.'::isAuthenticated()');
		}
		return $this->_user;
		}
	
	
	
	/***********************************************************************************************************************
	 * Atrributes section
	 * 
	 * @author Matthias Crauwels <matthias.crauwels@ugent.be>, Ghent University, Belgium
	 * 
	 ***********************************************************************************************************************/
	/**
	 * The Authenticated users attributes. Written by CASClient::setAttributes(), read by CASClient::getAttributes().
	 * @attention client applications should use phpCAS::getAttributes().
	 *
	 * @hideinitializer
	 * @private
	 */	
	var $_attributes = array();
	
	function setAttributes($attributes)	
		{ $this->_attributes = $attributes; }
	
	function getAttributes() {
		if ( empty($this->_user) ) { // if no user is set, there shouldn't be any attributes also...
			phpCAS::error('this method should be used only after '.__CLASS__.'::forceAuthentication() or '.__CLASS__.'::isAuthenticated()');
		}
		return $this->_attributes;
	}
	
	function hasAttributes()
		{ return !empty($this->_attributes); }
	
	function hasAttribute($key)
		{ return (is_array($this->_attributes) && array_key_exists($key, $this->_attributes)); }
	
	function getAttribute($key)	{
		if($this->hasAttribute($key)) {
			return $this->_attributes[$key];
		}
	}
	
	/**
	 * This method is called to renew the authentication of the user
	 * If the user is authenticated, renew the connection
	 * If not, redirect to CAS
	 * @public
	 */
	function renewAuthentication(){
		phpCAS::traceBegin();
		// Either way, the user is authenticated by CAS
		if( isset( $_SESSION['phpCAS']['auth_checked'] ) )
			unset($_SESSION['phpCAS']['auth_checked']);
		if ( $this->isAuthenticated() ) {
			phpCAS::trace('user already authenticated; renew');
			$this->redirectToCas(false,true);
		} else {
			$this->redirectToCas();
		}
		phpCAS::traceEnd();
	}
	
	/**
	 * This method is called to be sure that the user is authenticated. When not 
	 * authenticated, halt by redirecting to the CAS server; otherwise return TRUE.
	 * @return TRUE when the user is authenticated; otherwise halt.
	 * @public
	 */
	function forceAuthentication()
		{
		phpCAS::traceBegin();
		
		if ( $this->isAuthenticated() ) {
			// the user is authenticated, nothing to be done.
			phpCAS::trace('no need to authenticate');
			$res = TRUE;
		} else {
			// the user is not authenticated, redirect to the CAS server
			if (isset($_SESSION['phpCAS']['auth_checked'])) {
				unset($_SESSION['phpCAS']['auth_checked']);
			}
			$this->redirectToCas(FALSE/* no gateway */);	
			// never reached
			$res = FALSE;
		}
		phpCAS::traceEnd($res);
		return $res;
		}
	
	/**
	 * An integer that gives the number of times authentication will be cached before rechecked.
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_cache_times_for_auth_recheck = 0;
	
	/**
	 * Set the number of times authentication will be cached before rechecked.
	 *
	 * @param $n an integer.
	 *
	 * @public
	 */
	function setCacheTimesForAuthRecheck($n)
		{
		$this->_cache_times_for_auth_recheck = $n;
		}
	
	/**
	 * This method is called to check whether the user is authenticated or not.
	 * @return TRUE when the user is authenticated, FALSE otherwise.
	 * @public
	 */
	function checkAuthentication()
		{
		phpCAS::traceBegin();
		if ( $this->isAuthenticated() ) {
            phpCAS::trace('user is authenticated');
			$res = TRUE;
		} else if (isset($_SESSION['phpCAS']['auth_checked'])) {
            // the previous request has redirected the client to the CAS server with gateway=true
            // comment line bellow to
//			unset($_SESSION['phpCAS']['auth_checked']);
            $res = FALSE;
		} else {
//        $_SESSION['phpCAS']['auth_checked'] = true;
			//	    $this->redirectToCas(TRUE/* gateway */);	
			//	    // never reached
			//	    $res = FALSE;
			// avoid a check against CAS on every request
			if (! isset($_SESSION['phpCAS']['unauth_count']) )
				$_SESSION['phpCAS']['unauth_count'] = -2; // uninitialized
			
			if (($_SESSION['phpCAS']['unauth_count'] != -2 && $this->_cache_times_for_auth_recheck == -1) 
					|| ($_SESSION['phpCAS']['unauth_count'] >= 0 && $_SESSION['phpCAS']['unauth_count'] < $this->_cache_times_for_auth_recheck))
			{
				$res = FALSE;
				
				if ($this->_cache_times_for_auth_recheck != -1)
				{
					$_SESSION['phpCAS']['unauth_count']++;
					phpCAS::trace('user is not authenticated (cached for '.$_SESSION['phpCAS']['unauth_count'].' times of '.$this->_cache_times_for_auth_recheck.')');
				}
				else
				{
					phpCAS::trace('user is not authenticated (cached for until login pressed)');
				}
			}
			else
			{
				$_SESSION['phpCAS']['unauth_count'] = 0;
				$_SESSION['phpCAS']['auth_checked'] = true;
				phpCAS::trace('user is not authenticated (cache reset)');
				// $this->redirectToCas(TRUE/* gateway */);
				// never reached
				$res = FALSE;
			}
		}
		phpCAS::traceEnd($res);
		return $res;
		}
	
	/**
	 * This method is called to check if the user is authenticated (previously or by
	 * tickets given in the URL).
	 *
	 * @return TRUE when the user is authenticated. Also may redirect to the same URL without the ticket.
	 *
	 * @public
	 */
	function isAuthenticated()
		{
		phpCAS::traceBegin();
		$res = FALSE;
		$validate_url = '';
		
		if ( $this->wasPreviouslyAuthenticated() ) {
			// the user has already (previously during the session) been
			// authenticated, nothing to be done.
			phpCAS::trace('user was already authenticated, no need to look for tickets');
			$res = TRUE;
		}
		else {
			if ( $this->hasST() ) {
				// if a Service Ticket was given, validate it
				phpCAS::trace('ST `'.$this->getST().'\' is present');
				$this->validateST($validate_url,$text_response,$tree_response); // if it fails, it halts
				phpCAS::trace('ST `'.$this->getST().'\' was validated');
				if ( $this->isProxy() ) {
					$this->validatePGT($validate_url,$text_response,$tree_response); // idem
					phpCAS::trace('PGT `'.$this->getPGT().'\' was validated');
					$_SESSION['phpCAS']['pgt'] = $this->getPGT();
				}
				$_SESSION['phpCAS']['user'] = $this->getUser();
				$res = TRUE;
			}
			elseif ( $this->hasPT() ) {
				// if a Proxy Ticket was given, validate it
				phpCAS::trace('PT `'.$this->getPT().'\' is present');
				$this->validatePT($validate_url,$text_response,$tree_response); // note: if it fails, it halts
				phpCAS::trace('PT `'.$this->getPT().'\' was validated');
				if ( $this->isProxy() ) {
					$this->validatePGT($validate_url,$text_response,$tree_response); // idem
					phpCAS::trace('PGT `'.$this->getPGT().'\' was validated');
					$_SESSION['phpCAS']['pgt'] = $this->getPGT();
				}
				$_SESSION['phpCAS']['user'] = $this->getUser();
				$res = TRUE;
			}
			elseif ( $this->hasSA() ) {
				// if we have a SAML ticket, validate it.
				phpCAS::trace('SA `'.$this->getSA().'\' is present');
				$this->validateSA($validate_url,$text_response,$tree_response); // if it fails, it halts
				phpCAS::trace('SA `'.$this->getSA().'\' was validated');
				$_SESSION['phpCAS']['user'] = $this->getUser();
				$_SESSION['phpCAS']['attributes'] = $this->getAttributes();
				$res = TRUE;
			}
			else {
				// no ticket given, not authenticated
				phpCAS::trace('no ticket found');
			}
			if ($res) {
				// if called with a ticket parameter, we need to redirect to the app without the ticket so that CAS-ification is transparent to the browser (for later POSTS)
				// most of the checks and errors should have been made now, so we're safe for redirect without masking error messages.
				header('Location: '.$this->getURL());
				phpCAS::log( "Prepare redirect to : ".$this->getURL() );
			}
		}
		
		phpCAS::traceEnd($res);
		return $res;
		}
	
	/**
	 * This method tells if the current session is authenticated.
	 * @return true if authenticated based soley on $_SESSION variable
	 * @since 0.4.22 by Brendan Arnold
	 */
	function isSessionAuthenticated ()
		{
		return !empty($_SESSION['phpCAS']['user']);
		}
	
	/**
	 * This method tells if the user has already been (previously) authenticated
	 * by looking into the session variables.
	 *
	 * @note This function switches to callback mode when needed.
	 *
	 * @return TRUE when the user has already been authenticated; FALSE otherwise.
	 *
	 * @private
	 */
	function wasPreviouslyAuthenticated()
		{
		phpCAS::traceBegin();
		
		if ( $this->isCallbackMode() ) {
			$this->callback();
		}
		
		$auth = FALSE;
		
		if ( $this->isProxy() ) {
			// CAS proxy: username and PGT must be present
			if ( $this->isSessionAuthenticated() && !empty($_SESSION['phpCAS']['pgt']) ) {
				// authentication already done
				$this->setUser($_SESSION['phpCAS']['user']);
				$this->setPGT($_SESSION['phpCAS']['pgt']);
				phpCAS::trace('user = `'.$_SESSION['phpCAS']['user'].'\', PGT = `'.$_SESSION['phpCAS']['pgt'].'\''); 
				$auth = TRUE;
			} elseif ( $this->isSessionAuthenticated() && empty($_SESSION['phpCAS']['pgt']) ) {
				// these two variables should be empty or not empty at the same time
				phpCAS::trace('username found (`'.$_SESSION['phpCAS']['user'].'\') but PGT is empty');
				// unset all tickets to enforce authentication
				unset($_SESSION['phpCAS']);
				$this->setST('');
				$this->setPT('');
			} elseif ( !$this->isSessionAuthenticated() && !empty($_SESSION['phpCAS']['pgt']) ) {
				// these two variables should be empty or not empty at the same time
				phpCAS::trace('PGT found (`'.$_SESSION['phpCAS']['pgt'].'\') but username is empty'); 
				// unset all tickets to enforce authentication
				unset($_SESSION['phpCAS']);
				$this->setST('');
				$this->setPT('');
			} else {
				phpCAS::trace('neither user not PGT found'); 
			}
		} else {
			// `simple' CAS client (not a proxy): username must be present
			if ( $this->isSessionAuthenticated() ) {
				// authentication already done
				$this->setUser($_SESSION['phpCAS']['user']);
				if(isset($_SESSION['phpCAS']['attributes'])){
					$this->setAttributes($_SESSION['phpCAS']['attributes']);
				}
				phpCAS::trace('user = `'.$_SESSION['phpCAS']['user'].'\''); 
				$auth = TRUE;
			} else {
				phpCAS::trace('no user found');
			}
		}
		
		phpCAS::traceEnd($auth);
		return $auth;
		}
	
	/**
	 * This method is used to redirect the client to the CAS server.
	 * It is used by CASClient::forceAuthentication() and CASClient::checkAuthentication().
	 * @param $gateway true to check authentication, false to force it
	 * @param $renew true to force the authentication with the CAS server
	 * @public
	 */
	function redirectToCas($gateway=false,$renew=false){
		phpCAS::traceBegin();
		$cas_url = $this->getServerLoginURL($gateway,$renew);
		header('Location: '.$cas_url);
		phpCAS::log( "Redirect to : ".$cas_url );
		
		$this->printHTMLHeader($this->getString(CAS_STR_AUTHENTICATION_WANTED));
		
		printf('<p>'.$this->getString(CAS_STR_SHOULD_HAVE_BEEN_REDIRECTED).'</p>',$cas_url);
		$this->printHTMLFooter();
		
		phpCAS::traceExit();
		exit();
	}
	
	
	/**
	 * This method is used to logout from CAS.
	 * @params $params an array that contains the optional url and service parameters that will be passed to the CAS server
	 * @public
	 */
	function logout($params) {
		phpCAS::traceBegin();
		$cas_url = $this->getServerLogoutURL();
		$paramSeparator = '?';
		if (isset($params['url'])) {
			$cas_url = $cas_url . $paramSeparator . "url=" . urlencode($params['url']); 
			$paramSeparator = '&';
		}
		if (isset($params['service'])) {
			$cas_url = $cas_url . $paramSeparator . "service=" . urlencode($params['service']); 
		}
		header('Location: '.$cas_url);
		phpCAS::log( "Prepare redirect to : ".$cas_url );
		
		session_unset();
		session_destroy();
		
		$this->printHTMLHeader($this->getString(CAS_STR_LOGOUT));
		printf('<p>'.$this->getString(CAS_STR_SHOULD_HAVE_BEEN_REDIRECTED).'</p>',$cas_url);
		$this->printHTMLFooter();
		
		phpCAS::traceExit();
		exit();
	}
	
	/**
	 * @return true if the current request is a logout request.
	 * @private
	 */
	function isLogoutRequest() {
		return !empty($_POST['logoutRequest']);
	}
	
	/**
	 * @return true if a logout request is allowed.
	 * @private
	 */
	function isLogoutRequestAllowed() {
	}
	
	/**
	 * This method handles logout requests.
	 * @param $check_client true to check the client bofore handling the request, 
	 * false not to perform any access control. True by default.
	 * @param $allowed_clients an array of host names allowed to send logout requests. 
	 * By default, only the CAs server (declared in the constructor) will be allowed.
	 * @public
	 */
	function handleLogoutRequests($check_client=true, $allowed_clients=false) {
		phpCAS::traceBegin();
		if (!$this->isLogoutRequest()) {
			phpCAS::log("Not a logout request");
			phpCAS::traceEnd();
			return;
		}
		phpCAS::log("Logout requested");
		phpCAS::log("SAML REQUEST: ".$_POST['logoutRequest']);
		if ($check_client) {
			if (!$allowed_clients) {
				$allowed_clients = array( $this->getServerHostname() ); 
			}
			$client_ip = $_SERVER['REMOTE_ADDR'];
			$client = gethostbyaddr($client_ip);
			phpCAS::log("Client: ".$client."/".$client_ip); 
			$allowed = false;
			foreach ($allowed_clients as $allowed_client) {
				if (($client == $allowed_client) or ($client_ip == $allowed_client)) { 
					phpCAS::log("Allowed client '".$allowed_client."' matches, logout request is allowed");
					$allowed = true;
					break;
				} else {
					phpCAS::log("Allowed client '".$allowed_client."' does not match");
				}
			}
			if (!$allowed) {
				phpCAS::error("Unauthorized logout request from client '".$client."'");
				printf("Unauthorized!");
				phpCAS::traceExit();
				exit();
			}
		} else {
			phpCAS::log("No access control set");
		}
		// Extract the ticket from the SAML Request
		preg_match("|<samlp:SessionIndex>(.*)</samlp:SessionIndex>|", $_POST['logoutRequest'], $tick, PREG_OFFSET_CAPTURE, 3);
		$wrappedSamlSessionIndex = preg_replace('|<samlp:SessionIndex>|','',$tick[0][0]);
		$ticket2logout = preg_replace('|</samlp:SessionIndex>|','',$wrappedSamlSessionIndex);
		phpCAS::log("Ticket to logout: ".$ticket2logout);
		$session_id = preg_replace('/[^\w]/','',$ticket2logout);
		phpCAS::log("Session id: ".$session_id);
		
		// destroy a possible application session created before phpcas
		if(session_id()){
			session_unset();
			session_destroy();
		}
		// fix session ID
		session_id($session_id);
		$_COOKIE[session_name()]=$session_id;
		$_GET[session_name()]=$session_id;
		
		// Overwrite session
		session_start();	
		session_unset();
		session_destroy();
		printf("Disconnected!");
		phpCAS::traceExit();
		exit();
	}
	
	/** @} */
	
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	// XX                                                                    XX
	// XX                  BASIC CLIENT FEATURES (CAS 1.0)                   XX
	// XX                                                                    XX
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	
	// ########################################################################
	//  ST
	// ########################################################################
	/**
	 * @addtogroup internalBasic
	 * @{
	 */  
	
	/**
	 * the Service Ticket provided in the URL of the request if present
	 * (empty otherwise). Written by CASClient::CASClient(), read by 
	 * CASClient::getST() and CASClient::hasPGT().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_st = '';
	
	/**
	 * This method returns the Service Ticket provided in the URL of the request.
	 * @return The service ticket.
	 * @private
	 */
	function getST()
		{ return $this->_st; }
	
	/**
	 * This method stores the Service Ticket.
	 * @param $st The Service Ticket.
	 * @private
	 */
	function setST($st)
		{ $this->_st = $st; }
	
	/**
	 * This method tells if a Service Ticket was stored.
	 * @return TRUE if a Service Ticket has been stored.
	 * @private
	 */
	function hasST()
		{ return !empty($this->_st); }
	
	/** @} */
	
	// ########################################################################
	//  ST VALIDATION
	// ########################################################################
	/**
	 * @addtogroup internalBasic
	 * @{
	 */  
	
	/**
	 * the certificate of the CAS server.
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_cas_server_cert = '';
	
	/**
	 * the certificate of the CAS server CA.
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_cas_server_ca_cert = '';
	
	/**
	 * Set to true not to validate the CAS server.
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_no_cas_server_validation = false;
	
	/**
	 * Set the certificate of the CAS server.
	 *
	 * @param $cert the PEM certificate
	 */
	function setCasServerCert($cert)
		{
		$this->_cas_server_cert = $cert;
		}
	
	/**
	 * Set the CA certificate of the CAS server.
	 *
	 * @param $cert the PEM certificate of the CA that emited the cert of the server
	 */
	function setCasServerCACert($cert)
		{
		$this->_cas_server_ca_cert = $cert;
		}
	
	/**
	 * Set no SSL validation for the CAS server.
	 */
	function setNoCasServerValidation()
		{
		$this->_no_cas_server_validation = true;
		}
	
	/**
	 * This method is used to validate a ST; halt on failure, and sets $validate_url,
	 * $text_reponse and $tree_response on success. These parameters are used later
	 * by CASClient::validatePGT() for CAS proxies.
	 * Used for all CAS 1.0 validations
	 * @param $validate_url the URL of the request to the CAS server.
	 * @param $text_response the response of the CAS server, as is (XML text).
	 * @param $tree_response the response of the CAS server, as a DOM XML tree.
	 *
	 * @return bool TRUE when successfull, halt otherwise by calling CASClient::authError().
	 *
	 * @private
	 */
	function validateST($validate_url,&$text_response,&$tree_response)
		{
		phpCAS::traceBegin();
		// build the URL to validate the ticket
		$validate_url = $this->getServerServiceValidateURL().'&ticket='.$this->getST();
		if ( $this->isProxy() ) {
			// pass the callback url for CAS proxies
			$validate_url .= '&pgtUrl='.$this->getCallbackURL();
		}
		
		// open and read the URL
		if ( !$this->readURL($validate_url,''/*cookies*/,$headers,$text_response,$err_msg) ) {
			phpCAS::trace('could not open URL \''.$validate_url.'\' to validate ('.$err_msg.')');
			$this->authError('ST not validated',
				$validate_url,
				TRUE/*$no_response*/);
		}
		
		// analyze the result depending on the version
		switch ($this->getServerVersion()) {
			case CAS_VERSION_1_0:
				if (preg_match('/^no\n/',$text_response)) {
					phpCAS::trace('ST has not been validated');
					$this->authError('ST not validated',
						$validate_url,
						FALSE/*$no_response*/,
						FALSE/*$bad_response*/,
						$text_response);
				}
				if (!preg_match('/^yes\n/',$text_response)) {
					phpCAS::trace('ill-formed response');
					$this->authError('ST not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				// ST has been validated, extract the user name
				$arr = preg_split('/\n/',$text_response);
				$this->setUser(trim($arr[1]));
				break;
			case CAS_VERSION_2_0:
				// read the response of the CAS server into a DOM object
				if ( !($dom = domxml_open_mem($text_response))) {
					phpCAS::trace('domxml_open_mem() failed');
					$this->authError('ST not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				// read the root node of the XML tree
				if ( !($tree_response = $dom->document_element()) ) {
					phpCAS::trace('document_element() failed');
					$this->authError('ST not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				// insure that tag name is 'serviceResponse'
				if ( $tree_response->node_name() != 'serviceResponse' ) {
					phpCAS::trace('bad XML root node (should be `serviceResponse\' instead of `'.$tree_response->node_name().'\'');
					$this->authError('ST not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				if ( sizeof($success_elements = $tree_response->get_elements_by_tagname("authenticationSuccess")) != 0) {
					// authentication succeded, extract the user name
					if ( sizeof($user_elements = $success_elements[0]->get_elements_by_tagname("user")) == 0) {
						phpCAS::trace('<authenticationSuccess> found, but no <user>');
						$this->authError('ST not validated',
							$validate_url,
							FALSE/*$no_response*/,
							TRUE/*$bad_response*/,
							$text_response);
					}
					$user = trim($user_elements[0]->get_content());
					phpCAS::trace('user = `'.$user);
					$this->setUser($user);
					
				} else if ( sizeof($failure_elements = $tree_response->get_elements_by_tagname("authenticationFailure")) != 0) {
					phpCAS::trace('<authenticationFailure> found');
					// authentication failed, extract the error code and message
					$this->authError('ST not validated',
						$validate_url,
						FALSE/*$no_response*/,
						FALSE/*$bad_response*/,
						$text_response,
						$failure_elements[0]->get_attribute('code')/*$err_code*/,
						trim($failure_elements[0]->get_content())/*$err_msg*/);
				} else {
					phpCAS::trace('neither <authenticationSuccess> nor <authenticationFailure> found');
					$this->authError('ST not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				break;
		}
		
		// at this step, ST has been validated and $this->_user has been set,
		phpCAS::traceEnd(TRUE);
		return TRUE;
		}
	
	// ########################################################################
	//  SAML VALIDATION
	// ########################################################################
	/**
	 * @addtogroup internalBasic
	 * @{
	 */
	
	/**
	 * This method is used to validate a SAML TICKET; halt on failure, and sets $validate_url,
	 * $text_reponse and $tree_response on success. These parameters are used later
	 * by CASClient::validatePGT() for CAS proxies.
	 *
	 * @param $validate_url the URL of the request to the CAS server.
	 * @param $text_response the response of the CAS server, as is (XML text).
	 * @param $tree_response the response of the CAS server, as a DOM XML tree.
	 *
	 * @return bool TRUE when successfull, halt otherwise by calling CASClient::authError().
	 *
	 * @private
	 */
	function validateSA($validate_url,&$text_response,&$tree_response)
		{
		phpCAS::traceBegin();
		
		// build the URL to validate the ticket
		$validate_url = $this->getServerSamlValidateURL();
		
		// open and read the URL
		if ( !$this->readURL($validate_url,''/*cookies*/,$headers,$text_response,$err_msg) ) {
			phpCAS::trace('could not open URL \''.$validate_url.'\' to validate ('.$err_msg.')');
			$this->authError('SA not validated', $validate_url, TRUE/*$no_response*/);
		}
		
		phpCAS::trace('server version: '.$this->getServerVersion());
		
		// analyze the result depending on the version
		switch ($this->getServerVersion()) {
			case SAML_VERSION_1_1:
				
				// read the response of the CAS server into a DOM object
				if ( !($dom = domxml_open_mem($text_response))) {
					phpCAS::trace('domxml_open_mem() failed');
					$this->authError('SA not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				// read the root node of the XML tree
				if ( !($tree_response = $dom->document_element()) ) {
					phpCAS::trace('document_element() failed');
					$this->authError('SA not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				// insure that tag name is 'Envelope'
				if ( $tree_response->node_name() != 'Envelope' ) {
					phpCAS::trace('bad XML root node (should be `Envelope\' instead of `'.$tree_response->node_name().'\'');
					$this->authError('SA not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				// check for the NameIdentifier tag in the SAML response
				if ( sizeof($success_elements = $tree_response->get_elements_by_tagname("NameIdentifier")) != 0) {
					phpCAS::trace('NameIdentifier found');
					$user = trim($success_elements[0]->get_content());
					phpCAS::trace('user = `'.$user.'`');
					$this->setUser($user);
					$this->setSessionAttributes($text_response);
				} else {
					phpCAS::trace('no <NameIdentifier> tag found in SAML payload');
					$this->authError('SA not validated',
						$validate_url,
						FALSE/*$no_response*/,
						TRUE/*$bad_response*/,
						$text_response);
				}
				break;
		}
		
		// at this step, ST has been validated and $this->_user has been set,
		phpCAS::traceEnd(TRUE);
		return TRUE;
		}
	
	/**
	 * This method will parse the DOM and pull out the attributes from the SAML
	 * payload and put them into an array, then put the array into the session.
	 *
	 * @param $text_response the SAML payload.
	 * @return bool TRUE when successfull, halt otherwise by calling CASClient::authError().
	 *
	 * @private
	 */
	function setSessionAttributes($text_response)
		{
		phpCAS::traceBegin();
		
		$result = FALSE;
		
		if (isset($_SESSION[SAML_ATTRIBUTES])) {
			phpCAS::trace("session attrs already set.");  //testbml - do we care?
		}
		
		$attr_array = array();
		
		if (($dom = domxml_open_mem($text_response))) {
			$xPath = $dom->xpath_new_context();
			$xPath->xpath_register_ns('samlp', 'urn:oasis:names:tc:SAML:1.0:protocol');
			$xPath->xpath_register_ns('saml', 'urn:oasis:names:tc:SAML:1.0:assertion');
			$nodelist = $xPath->xpath_eval("//saml:Attribute");
			$attrs = $nodelist->nodeset;
			phpCAS::trace($text_response);
			foreach($attrs as $attr){
				$xres = $xPath->xpath_eval("saml:AttributeValue", $attr);
				$name = $attr->get_attribute("AttributeName");
				$value_array = array();
				foreach($xres->nodeset as $node){
					$value_array[] = $node->get_content();
					
				}
				phpCAS::trace("* " . $name . "=" . $value_array);
				$attr_array[$name] = $value_array;
			}
			$_SESSION[SAML_ATTRIBUTES] = $attr_array;
			// UGent addition...
			foreach($attr_array as $attr_key => $attr_value) {
				if(count($attr_value) > 1) {
					$this->_attributes[$attr_key] = $attr_value;
				}
				else {
					$this->_attributes[$attr_key] = $attr_value[0];
				}
			}
			$result = TRUE;
		}
		phpCAS::traceEnd($result);
		return $result;
		}
	
	/** @} */
	
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	// XX                                                                    XX
	// XX                     PROXY FEATURES (CAS 2.0)                       XX
	// XX                                                                    XX
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	
	// ########################################################################
	//  PROXYING
	// ########################################################################
	/**
	 * @addtogroup internalProxy
	 * @{
	 */
	
	/**
	 * A boolean telling if the client is a CAS proxy or not. Written by CASClient::CASClient(), 
	 * read by CASClient::isProxy().
	 *
	 * @private
	 */
	var $_proxy;
	
	/**
	 * Tells if a CAS client is a CAS proxy or not
	 *
	 * @return TRUE when the CAS client is a CAs proxy, FALSE otherwise
	 *
	 * @private
	 */
	function isProxy()
		{
		return $this->_proxy;
		}
	
	/** @} */
	// ########################################################################
	//  PGT
	// ########################################################################
	/**
	 * @addtogroup internalProxy
	 * @{
	 */  
	
	/**
	 * the Proxy Grnting Ticket given by the CAS server (empty otherwise). 
	 * Written by CASClient::setPGT(), read by CASClient::getPGT() and CASClient::hasPGT().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_pgt = '';
	
	/**
	 * This method returns the Proxy Granting Ticket given by the CAS server.
	 * @return The Proxy Granting Ticket.
	 * @private
	 */
	function getPGT()
		{ return $this->_pgt; }
	
	/**
	 * This method stores the Proxy Granting Ticket.
	 * @param $pgt The Proxy Granting Ticket.
	 * @private
	 */
	function setPGT($pgt)
		{ $this->_pgt = $pgt; }
	
	/**
	 * This method tells if a Proxy Granting Ticket was stored.
	 * @return TRUE if a Proxy Granting Ticket has been stored.
	 * @private
	 */
	function hasPGT()
		{ return !empty($this->_pgt); }
	
	/** @} */
	
	// ########################################################################
	//  CALLBACK MODE
	// ########################################################################
	/**
	 * @addtogroup internalCallback
	 * @{
	 */  
	/**
	 * each PHP script using phpCAS in proxy mode is its own callback to get the
	 * PGT back from the CAS server. callback_mode is detected by the constructor
	 * thanks to the GET parameters.
	 */
	
	/**
	 * a boolean to know if the CAS client is running in callback mode. Written by
	 * CASClient::setCallBackMode(), read by CASClient::isCallbackMode().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_callback_mode = FALSE;
	
	/**
	 * This method sets/unsets callback mode.
	 *
	 * @param $callback_mode TRUE to set callback mode, FALSE otherwise.
	 *
	 * @private
	 */
	function setCallbackMode($callback_mode)
		{
		$this->_callback_mode = $callback_mode;
		}
	
	/**
	 * This method returns TRUE when the CAs client is running i callback mode, 
	 * FALSE otherwise.
	 *
	 * @return A boolean.
	 *
	 * @private
	 */
	function isCallbackMode()
		{
		return $this->_callback_mode;
		}
	
	/**
	 * the URL that should be used for the PGT callback (in fact the URL of the 
	 * current request without any CGI parameter). Written and read by 
	 * CASClient::getCallbackURL().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_callback_url = '';
	
	/**
	 * This method returns the URL that should be used for the PGT callback (in
	 * fact the URL of the current request without any CGI parameter, except if
	 * phpCAS::setFixedCallbackURL() was used).
	 *
	 * @return The callback URL
	 *
	 * @private
	 */
	function getCallbackURL()
		{
		// the URL is built when needed only
		if ( empty($this->_callback_url) ) {
			$final_uri = '';
			// remove the ticket if present in the URL
			$final_uri = 'https://';
			/* replaced by Julien Marchal - v0.4.6
			 * $this->uri .= $_SERVER['SERVER_NAME'];
			 */
			if(empty($_SERVER['HTTP_X_FORWARDED_SERVER'])){
				/* replaced by teedog - v0.4.12
				 * $final_uri .= $_SERVER['SERVER_NAME'];
				 */
				if (empty($_SERVER['SERVER_NAME'])) {
					$final_uri .= $_SERVER['HTTP_HOST'];
				} else {
					$final_uri .= $_SERVER['SERVER_NAME'];
				}
			} else {
				$final_uri .= $_SERVER['HTTP_X_FORWARDED_SERVER'];
			}
			if ( ($this->isHttps() && $_SERVER['SERVER_PORT']!=443)
					|| (!$this->isHttps() && $_SERVER['SERVER_PORT']!=80) ) {
				$final_uri .= ':';
				$final_uri .= $_SERVER['SERVER_PORT'];
			}
			$request_uri = $_SERVER['REQUEST_URI'];
			$request_uri = preg_replace('/\?.*$/','',$request_uri);
			$final_uri .= $request_uri;
			$this->setCallbackURL($final_uri);
		}
		return $this->_callback_url;
		}
	
	/**
	 * This method sets the callback url.
	 *
	 * @param $callback_url url to set callback 
	 *
	 * @private
	 */
	function setCallbackURL($url)
		{
		return $this->_callback_url = $url;
		}
	
	/**
	 * This method is called by CASClient::CASClient() when running in callback
	 * mode. It stores the PGT and its PGT Iou, prints its output and halts.
	 *
	 * @private
	 */
	function callback()
		{
		phpCAS::traceBegin();
		$this->printHTMLHeader('phpCAS callback');
		$pgt_iou = $_GET['pgtIou'];
		$pgt = $_GET['pgtId'];
		phpCAS::trace('Storing PGT `'.$pgt.'\' (id=`'.$pgt_iou.'\')');
		echo '<p>Storing PGT `'.$pgt.'\' (id=`'.$pgt_iou.'\').</p>';
		$this->storePGT($pgt,$pgt_iou);
		$this->printHTMLFooter();
		phpCAS::traceExit();
		exit();
		}
	
	/** @} */
	
	// ########################################################################
	//  PGT STORAGE
	// ########################################################################
	/**
	 * @addtogroup internalPGTStorage
	 * @{
	 */  
	
	/**
	 * an instance of a class inheriting of PGTStorage, used to deal with PGT
	 * storage. Created by CASClient::setPGTStorageFile() or CASClient::setPGTStorageDB(), used 
	 * by CASClient::setPGTStorageFile(), CASClient::setPGTStorageDB() and CASClient::initPGTStorage().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_pgt_storage = null;
	
	/**
	 * This method is used to initialize the storage of PGT's.
	 * Halts on error.
	 *
	 * @private
	 */
	function initPGTStorage()
		{
		// if no SetPGTStorageXxx() has been used, default to file
		if ( !is_object($this->_pgt_storage) ) {
			$this->setPGTStorageFile();
		}
		
		// initializes the storage
		$this->_pgt_storage->init();
		}
	
	/**
	 * This method stores a PGT. Halts on error.
	 *
	 * @param $pgt the PGT to store
	 * @param $pgt_iou its corresponding Iou
	 *
	 * @private
	 */
	function storePGT($pgt,$pgt_iou)
		{
		// ensure that storage is initialized
		$this->initPGTStorage();
		// writes the PGT
		$this->_pgt_storage->write($pgt,$pgt_iou);
		}
	
	/**
	 * This method reads a PGT from its Iou and deletes the corresponding storage entry.
	 *
	 * @param $pgt_iou the PGT Iou
	 *
	 * @return The PGT corresponding to the Iou, FALSE when not found.
	 *
	 * @private
	 */
	function loadPGT($pgt_iou)
		{
		// ensure that storage is initialized
		$this->initPGTStorage();
		// read the PGT
		return $this->_pgt_storage->read($pgt_iou);
		}
	
	/**
	 * This method is used to tell phpCAS to store the response of the
	 * CAS server to PGT requests onto the filesystem. 
	 *
	 * @param $format the format used to store the PGT's (`plain' and `xml' allowed)
	 * @param $path the path where the PGT's should be stored
	 *
	 * @public
	 */
	function setPGTStorageFile($format='',
		$path='')
		{
		// check that the storage has not already been set
		if ( is_object($this->_pgt_storage) ) {
			phpCAS::error('PGT storage already defined');
		}
		
		// create the storage object
		$this->_pgt_storage = new PGTStorageFile($this,$format,$path);
		}
	
	/**
	 * This method is used to tell phpCAS to store the response of the
	 * CAS server to PGT requests into a database. 
	 * @note The connection to the database is done only when needed. 
	 * As a consequence, bad parameters are detected only when 
	 * initializing PGT storage.
	 *
	 * @param $user the user to access the data with
	 * @param $password the user's password
	 * @param $database_type the type of the database hosting the data
	 * @param $hostname the server hosting the database
	 * @param $port the port the server is listening on
	 * @param $database the name of the database
	 * @param $table the name of the table storing the data
	 *
	 * @public
	 */
	function setPGTStorageDB($user,
							 $password,
							 $database_type,
							 $hostname,
							 $port,
							 $database,
							 $table)
		{
		// check that the storage has not already been set
		if ( is_object($this->_pgt_storage) ) {
			phpCAS::error('PGT storage already defined');
		}
		
		// warn the user that he should use file storage...
		trigger_error('PGT storage into database is an experimental feature, use at your own risk',E_USER_WARNING);
		
		// create the storage object
		$this->_pgt_storage = new PGTStorageDB($this,$user,$password,$database_type,$hostname,$port,$database,$table);
		}
	
	// ########################################################################
	//  PGT VALIDATION
	// ########################################################################
	/**
	 * This method is used to validate a PGT; halt on failure.
	 * 
	 * @param $validate_url the URL of the request to the CAS server.
	 * @param $text_response the response of the CAS server, as is (XML text); result
	 * of CASClient::validateST() or CASClient::validatePT().
	 * @param $tree_response the response of the CAS server, as a DOM XML tree; result
	 * of CASClient::validateST() or CASClient::validatePT().
	 *
	 * @return bool TRUE when successfull, halt otherwise by calling CASClient::authError().
	 *
	 * @private
	 */
	function validatePGT(&$validate_url,$text_response,$tree_response)
		{
		// here cannot use phpCAS::traceBegin(); alongside domxml-php4-to-php5.php
		phpCAS::log('start validatePGT()');
		if ( sizeof($arr = $tree_response->get_elements_by_tagname("proxyGrantingTicket")) == 0) {
			phpCAS::trace('<proxyGrantingTicket> not found');
			// authentication succeded, but no PGT Iou was transmitted
			$this->authError('Ticket validated but no PGT Iou transmitted',
				$validate_url,
				FALSE/*$no_response*/,
				FALSE/*$bad_response*/,
				$text_response);
		} else {
			// PGT Iou transmitted, extract it
			$pgt_iou = trim($arr[0]->get_content());
			$pgt = $this->loadPGT($pgt_iou);
			if ( $pgt == FALSE ) {
				phpCAS::trace('could not load PGT');
				$this->authError('PGT Iou was transmitted but PGT could not be retrieved',
					$validate_url,
					FALSE/*$no_response*/,
					FALSE/*$bad_response*/,
					$text_response);
			}
			$this->setPGT($pgt);
		}
		// here, cannot use	phpCAS::traceEnd(TRUE); alongside domxml-php4-to-php5.php
		phpCAS::log('end validatePGT()');
		return TRUE;
		}
	
	// ########################################################################
	//  PGT VALIDATION
	// ########################################################################
	
	/**
	 * This method is used to retrieve PT's from the CAS server thanks to a PGT.
	 * 
	 * @param $target_service the service to ask for with the PT.
	 * @param $err_code an error code (PHPCAS_SERVICE_OK on success).
	 * @param $err_msg an error message (empty on success).
	 *
	 * @return a Proxy Ticket, or FALSE on error.
	 *
	 * @private
	 */
	function retrievePT($target_service,&$err_code,&$err_msg)
		{
		phpCAS::traceBegin();
		
		// by default, $err_msg is set empty and $pt to TRUE. On error, $pt is
		// set to false and $err_msg to an error message. At the end, if $pt is FALSE 
		// and $error_msg is still empty, it is set to 'invalid response' (the most
		// commonly encountered error).
		$err_msg = '';
		
		// build the URL to retrieve the PT
		//      $cas_url = $this->getServerProxyURL().'?targetService='.preg_replace('/&/','%26',$target_service).'&pgt='.$this->getPGT();
		$cas_url = $this->getServerProxyURL().'?targetService='.urlencode($target_service).'&pgt='.$this->getPGT();
		
		// open and read the URL
		if ( !$this->readURL($cas_url,''/*cookies*/,$headers,$cas_response,$err_msg) ) {
			phpCAS::trace('could not open URL \''.$cas_url.'\' to validate ('.$err_msg.')');
			$err_code = PHPCAS_SERVICE_PT_NO_SERVER_RESPONSE;
			$err_msg = 'could not retrieve PT (no response from the CAS server)';
			phpCAS::traceEnd(FALSE);
			return FALSE;
		}
		
		$bad_response = FALSE;
		
		if ( !$bad_response ) {
			// read the response of the CAS server into a DOM object
			if ( !($dom = @domxml_open_mem($cas_response))) {
				phpCAS::trace('domxml_open_mem() failed');
				// read failed
				$bad_response = TRUE;
			} 
		}
		
		if ( !$bad_response ) {
			// read the root node of the XML tree
			if ( !($root = $dom->document_element()) ) {
				phpCAS::trace('document_element() failed');
				// read failed
				$bad_response = TRUE;
			} 
		}
		
		if ( !$bad_response ) {
			// insure that tag name is 'serviceResponse'
			if ( $root->node_name() != 'serviceResponse' ) {
				phpCAS::trace('node_name() failed');
				// bad root node
				$bad_response = TRUE;
			} 
		}
		
		if ( !$bad_response ) {
			// look for a proxySuccess tag
			if ( sizeof($arr = $root->get_elements_by_tagname("proxySuccess")) != 0) {
				// authentication succeded, look for a proxyTicket tag
				if ( sizeof($arr = $root->get_elements_by_tagname("proxyTicket")) != 0) {
					$err_code = PHPCAS_SERVICE_OK;
					$err_msg = '';
					phpCAS::trace('original PT: '.trim($arr[0]->get_content()));
					$pt = trim($arr[0]->get_content());
					phpCAS::traceEnd($pt);
					return $pt;
				} else {
					phpCAS::trace('<proxySuccess> was found, but not <proxyTicket>');
				}
			} 
			// look for a proxyFailure tag
			else if ( sizeof($arr = $root->get_elements_by_tagname("proxyFailure")) != 0) {
				// authentication failed, extract the error
				$err_code = PHPCAS_SERVICE_PT_FAILURE;
				$err_msg = 'PT retrieving failed (code=`'
					.$arr[0]->get_attribute('code')
					.'\', message=`'
					.trim($arr[0]->get_content())
					.'\')';
				phpCAS::traceEnd(FALSE);
				return FALSE;
			} else {
				phpCAS::trace('neither <proxySuccess> nor <proxyFailure> found');
			}
		}
		
		// at this step, we are sure that the response of the CAS server was ill-formed
		$err_code = PHPCAS_SERVICE_PT_BAD_SERVER_RESPONSE;
		$err_msg = 'Invalid response from the CAS server (response=`'.$cas_response.'\')';
		
		phpCAS::traceEnd(FALSE);
		return FALSE;
		}
	
	// ########################################################################
	// ACCESS TO EXTERNAL SERVICES
	// ########################################################################
	
	/**
	 * This method is used to acces a remote URL.
	 *
	 * @param $url the URL to access.
	 * @param $cookies an array containing cookies strings such as 'name=val'
	 * @param $headers an array containing the HTTP header lines of the response
	 * (an empty array on failure).
	 * @param $body the body of the response, as a string (empty on failure).
	 * @param $err_msg an error message, filled on failure.
	 *
	 * @return TRUE on success, FALSE otherwise (in this later case, $err_msg
	 * contains an error message).
	 *
	 * @private
	 */
	function readURL($url,$cookies,&$headers,&$body,&$err_msg)
		{
		phpCAS::traceBegin();
		$headers = '';
		$body = '';
		$err_msg = '';
		
		$res = TRUE;
		
		// initialize the CURL session
		$ch = curl_init($url);
		
		if (version_compare(PHP_VERSION,'5.1.3','>=')) {
			//only avaible in php5
			curl_setopt_array($ch, $this->_curl_options);
		} else {
			foreach ($this->_curl_options as $key => $value) {
				curl_setopt($ch, $key, $value);
			}
		}
		
		if ($this->_cas_server_cert == '' && $this->_cas_server_ca_cert == '' && !$this->_no_cas_server_validation) {
			phpCAS::error('one of the methods phpCAS::setCasServerCert(), phpCAS::setCasServerCACert() or phpCAS::setNoCasServerValidation() must be called.');
		}
		if ($this->_cas_server_cert != '' && $this->_cas_server_ca_cert != '') {
			// This branch added by IDMS. Seems phpCAS implementor got a bit confused about the curl options CURLOPT_SSLCERT and CURLOPT_CAINFO
			curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
			curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 1);
			curl_setopt($ch, CURLOPT_SSLCERT, $this->_cas_server_cert);
			curl_setopt($ch, CURLOPT_CAINFO, $this->_cas_server_ca_cert);
			curl_setopt($ch, CURLOPT_VERBOSE, '1');
			phpCAS::trace('CURL: Set all required opts for mutual authentication ------');
		} else if ($this->_cas_server_cert != '' ) {
			curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
			curl_setopt($ch, CURLOPT_SSLCERT, $this->_cas_server_cert);
		} else if ($this->_cas_server_ca_cert != '') {
			curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
			curl_setopt($ch, CURLOPT_CAINFO, $this->_cas_server_ca_cert);
		} else {
			curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 1);
			curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
		}
		
		// return the CURL output into a variable
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		// get the HTTP header with a callback
		$this->_curl_headers = array(); // empty the headers array
		curl_setopt($ch, CURLOPT_HEADERFUNCTION, array($this, '_curl_read_headers'));
		// add cookies headers
		if ( is_array($cookies) ) {
			curl_setopt($ch,CURLOPT_COOKIE,implode(';',$cookies));
		}
		// add extra stuff if SAML
		if ($this->hasSA()) {
			$more_headers = array ("soapaction: http://www.oasis-open.org/committees/security",
				"cache-control: no-cache",
				"pragma: no-cache",
				"accept: text/xml",
				"connection: keep-alive",
			"content-type: text/xml");
			
			curl_setopt($ch, CURLOPT_HTTPHEADER, $more_headers);
			curl_setopt($ch, CURLOPT_POST, 1);
			$data = $this->buildSAMLPayload();
			//phpCAS::trace('SAML Payload: '.print_r($data, TRUE));
			curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
		}
		// perform the query
		$buf = curl_exec ($ch);
		//phpCAS::trace('CURL: Call completed. Response body is: \''.$buf.'\'');
		if ( $buf === FALSE ) {
			phpCAS::trace('curl_exec() failed');
			$err_msg = 'CURL error #'.curl_errno($ch).': '.curl_error($ch);
			//phpCAS::trace('curl error: '.$err_msg);
			// close the CURL session
			curl_close ($ch);
			$res = FALSE;
		} else {
			// close the CURL session
			curl_close ($ch);
			
			$headers = $this->_curl_headers;
			$body = $buf;
		}
		
		phpCAS::traceEnd($res);
		return $res;
		}
	
	/**
	 * This method is used to build the SAML POST body sent to /samlValidate URL.
	 *
	 * @return the SOAP-encased SAMLP artifact (the ticket).
	 *
	 * @private
	 */
	function buildSAMLPayload()
		{
		phpCAS::traceBegin();
		
		//get the ticket
		$sa = $this->getSA();
		//phpCAS::trace("SA: ".$sa);
		
		$body=SAML_SOAP_ENV.SAML_SOAP_BODY.SAMLP_REQUEST.SAML_ASSERTION_ARTIFACT.$sa.SAML_ASSERTION_ARTIFACT_CLOSE.SAMLP_REQUEST_CLOSE.SAML_SOAP_BODY_CLOSE.SAML_SOAP_ENV_CLOSE;
		
		phpCAS::traceEnd($body);
		return ($body);
		}
	
	/**
	 * This method is the callback used by readURL method to request HTTP headers.
	 */
	var $_curl_headers = array();
	function _curl_read_headers($ch, $header)
		{
		$this->_curl_headers[] = $header;
		return strlen($header);
		}
	
	/**
	 * This method is used to access an HTTP[S] service.
	 * 
	 * @param $url the service to access.
	 * @param $err_code an error code Possible values are PHPCAS_SERVICE_OK (on
	 * success), PHPCAS_SERVICE_PT_NO_SERVER_RESPONSE, PHPCAS_SERVICE_PT_BAD_SERVER_RESPONSE,
	 * PHPCAS_SERVICE_PT_FAILURE, PHPCAS_SERVICE_NOT AVAILABLE.
	 * @param $output the output of the service (also used to give an error
	 * message on failure).
	 *
	 * @return TRUE on success, FALSE otherwise (in this later case, $err_code
	 * gives the reason why it failed and $output contains an error message).
	 *
	 * @public
	 */
	function serviceWeb($url,&$err_code,&$output)
		{
		phpCAS::traceBegin();
		// at first retrieve a PT
		$pt = $this->retrievePT($url,$err_code,$output);
		
		$res = TRUE;
		
		// test if PT was retrieved correctly
		if ( !$pt ) {
			// note: $err_code and $err_msg are filled by CASClient::retrievePT()
			phpCAS::trace('PT was not retrieved correctly');
			$res = FALSE;
		} else {
			// add cookies if necessary
			if ( is_array($_SESSION['phpCAS']['services'][$url]['cookies']) ) {
				foreach ( $_SESSION['phpCAS']['services'][$url]['cookies'] as $name => $val ) { 
					$cookies[] = $name.'='.$val;
				}
			}
			
			// build the URL including the PT
			if ( strstr($url,'?') === FALSE ) {
				$service_url = $url.'?ticket='.$pt;
			} else {
				$service_url = $url.'&ticket='.$pt;
			}
			
			phpCAS::trace('reading URL`'.$service_url.'\'');
			if ( !$this->readURL($service_url,$cookies,$headers,$output,$err_msg) ) {
				phpCAS::trace('could not read URL`'.$service_url.'\'');
				$err_code = PHPCAS_SERVICE_NOT_AVAILABLE;
				// give an error message
				$output = sprintf($this->getString(CAS_STR_SERVICE_UNAVAILABLE),
					$service_url,
					$err_msg);
				$res = FALSE;
			} else {
				// URL has been fetched, extract the cookies
				phpCAS::trace('URL`'.$service_url.'\' has been read, storing cookies:');
				foreach ( $headers as $header ) {
					// test if the header is a cookie
					if ( preg_match('/^Set-Cookie:/',$header) ) {
						// the header is a cookie, remove the beginning
						$header_val = preg_replace('/^Set-Cookie: */','',$header);
						// extract interesting information
						$name_val = strtok($header_val,'; ');
						// extract the name and the value of the cookie
						$cookie_name = strtok($name_val,'=');
						$cookie_val = strtok('=');
						// store the cookie 
						$_SESSION['phpCAS']['services'][$url]['cookies'][$cookie_name] = $cookie_val;
						phpCAS::trace($cookie_name.' -> '.$cookie_val);
					}
				}
			}
		}
		
		phpCAS::traceEnd($res);
		return $res;
		}
	
	/**
	 * This method is used to access an IMAP/POP3/NNTP service.
	 * 
	 * @param $url a string giving the URL of the service, including the mailing box
	 * for IMAP URLs, as accepted by imap_open().
	 * @param $service a string giving for CAS retrieve Proxy ticket
	 * @param $flags options given to imap_open().
	 * @param $err_code an error code Possible values are PHPCAS_SERVICE_OK (on
	 * success), PHPCAS_SERVICE_PT_NO_SERVER_RESPONSE, PHPCAS_SERVICE_PT_BAD_SERVER_RESPONSE,
	 * PHPCAS_SERVICE_PT_FAILURE, PHPCAS_SERVICE_NOT AVAILABLE.
	 * @param $err_msg an error message on failure
	 * @param $pt the Proxy Ticket (PT) retrieved from the CAS server to access the URL
	 * on success, FALSE on error).
	 *
	 * @return an IMAP stream on success, FALSE otherwise (in this later case, $err_code
	 * gives the reason why it failed and $err_msg contains an error message).
	 *
	 * @public
	 */
	function serviceMail($url,$service,$flags,&$err_code,&$err_msg,&$pt)
		{
		phpCAS::traceBegin();
		// at first retrieve a PT
		$pt = $this->retrievePT($service,$err_code,$output);
		
		$stream = FALSE;
		
		// test if PT was retrieved correctly
		if ( !$pt ) {
			// note: $err_code and $err_msg are filled by CASClient::retrievePT()
			phpCAS::trace('PT was not retrieved correctly');
		} else {
			phpCAS::trace('opening IMAP URL `'.$url.'\'...');
			$stream = @imap_open($url,$this->getUser(),$pt,$flags);
			if ( !$stream ) {
				phpCAS::trace('could not open URL');
				$err_code = PHPCAS_SERVICE_NOT_AVAILABLE;
				// give an error message
				$err_msg = sprintf($this->getString(CAS_STR_SERVICE_UNAVAILABLE),
					$service_url,
					var_export(imap_errors(),TRUE));
				$pt = FALSE;
				$stream = FALSE;
			} else {
				phpCAS::trace('ok');
			}
		}
		
		phpCAS::traceEnd($stream);
		return $stream;
		}
	
	/** @} */
	
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	// XX                                                                    XX
	// XX                  PROXIED CLIENT FEATURES (CAS 2.0)                 XX
	// XX                                                                    XX
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	
	// ########################################################################
	//  PT
	// ########################################################################
	/**
	 * @addtogroup internalProxied
	 * @{
	 */  
	
	/**
	 * the Proxy Ticket provided in the URL of the request if present
	 * (empty otherwise). Written by CASClient::CASClient(), read by 
	 * CASClient::getPT() and CASClient::hasPGT().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_pt = '';
	
	/**
	 * This method returns the Proxy Ticket provided in the URL of the request.
	 * @return The proxy ticket.
	 * @private
	 */
	function getPT()
		{
		//      return 'ST'.substr($this->_pt, 2);
		return $this->_pt;
		}
	
	/**
	 * This method stores the Proxy Ticket.
	 * @param $pt The Proxy Ticket.
	 * @private
	 */
	function setPT($pt)
		{ $this->_pt = $pt; }
	
	/**
	 * This method tells if a Proxy Ticket was stored.
	 * @return TRUE if a Proxy Ticket has been stored.
	 * @private
	 */
	function hasPT()
		{ return !empty($this->_pt); }
	/**
	 * This method returns the SAML Ticket provided in the URL of the request.
	 * @return The SAML ticket.
	 * @private
	 */
	function getSA()
		{ return 'ST'.substr($this->_sa, 2); }
	
	/**
	 * This method stores the SAML Ticket.
	 * @param $sa The SAML Ticket.
	 * @private
	 */
	function setSA($sa)
		{ $this->_sa = $sa; }
	
	/**
	 * This method tells if a SAML Ticket was stored.
	 * @return TRUE if a SAML Ticket has been stored.
	 * @private
	 */
	function hasSA()
		{ return !empty($this->_sa); }
	
	/** @} */
	// ########################################################################
	//  PT VALIDATION
	// ########################################################################
	/**
	 * @addtogroup internalProxied
	 * @{
	 */  
	
	/**
	 * This method is used to validate a ST or PT; halt on failure
	 * Used for all CAS 2.0 validations
	 * @return bool TRUE when successfull, halt otherwise by calling CASClient::authError().
	 *
	 * @private
	 */
	function validatePT(&$validate_url,&$text_response,&$tree_response)
		{
		phpCAS::traceBegin();
		// build the URL to validate the ticket
		$validate_url = $this->getServerProxyValidateURL().'&ticket='.$this->getPT();
		
		if ( $this->isProxy() ) {
			// pass the callback url for CAS proxies
			$validate_url .= '&pgtUrl='.$this->getCallbackURL();
		}
		
		// open and read the URL
		if ( !$this->readURL($validate_url,''/*cookies*/,$headers,$text_response,$err_msg) ) {
			phpCAS::trace('could not open URL \''.$validate_url.'\' to validate ('.$err_msg.')');
			$this->authError('PT not validated',
				$validate_url,
				TRUE/*$no_response*/);
		}
		
		// read the response of the CAS server into a DOM object
		if ( !($dom = domxml_open_mem($text_response))) {
			// read failed
			$this->authError('PT not validated',
				$validate_url,
				FALSE/*$no_response*/,
				TRUE/*$bad_response*/,
				$text_response);
		}
		// read the root node of the XML tree
		if ( !($tree_response = $dom->document_element()) ) {
			// read failed
			$this->authError('PT not validated',
				$validate_url,
				FALSE/*$no_response*/,
				TRUE/*$bad_response*/,
				$text_response);
		}
		// insure that tag name is 'serviceResponse'
		if ( $tree_response->node_name() != 'serviceResponse' ) {
			// bad root node
			$this->authError('PT not validated',
				$validate_url,
				FALSE/*$no_response*/,
				TRUE/*$bad_response*/,
				$text_response);
		}
		if ( sizeof($arr = $tree_response->get_elements_by_tagname("authenticationSuccess")) != 0) {
			// authentication succeded, extract the user name
			if ( sizeof($arr = $tree_response->get_elements_by_tagname("user")) == 0) {
				// no user specified => error
				$this->authError('PT not validated',
					$validate_url,
					FALSE/*$no_response*/,
					TRUE/*$bad_response*/,
					$text_response);
			}
			$this->setUser(trim($arr[0]->get_content()));
			
		} else if ( sizeof($arr = $tree_response->get_elements_by_tagname("authenticationFailure")) != 0) {
			// authentication succeded, extract the error code and message
			$this->authError('PT not validated',
				$validate_url,
				FALSE/*$no_response*/,
				FALSE/*$bad_response*/,
				$text_response,
				$arr[0]->get_attribute('code')/*$err_code*/,
				trim($arr[0]->get_content())/*$err_msg*/);
		} else {
			$this->authError('PT not validated',
				$validate_url,	
				FALSE/*$no_response*/,
				TRUE/*$bad_response*/,
				$text_response);
		}
		
		// at this step, PT has been validated and $this->_user has been set,
		
		phpCAS::traceEnd(TRUE);
		return TRUE;
		}
	
	/** @} */
	
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	// XX                                                                    XX
	// XX                               MISC                                 XX
	// XX                                                                    XX
	// XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
	
	/**
	 * @addtogroup internalMisc
	 * @{
	 */  
	
	// ########################################################################
	//  URL
	// ########################################################################
	/**
	 * the URL of the current request (without any ticket CGI parameter). Written 
	 * and read by CASClient::getURL().
	 *
	 * @hideinitializer
	 * @private
	 */
	var $_url = '';
	
	/**
	 * This method returns the URL of the current request (without any ticket
	 * CGI parameter).
	 *
	 * @return The URL
	 *
	 * @private
	 */
	function getURL()
		{
		phpCAS::traceBegin();
		// the URL is built when needed only
		if ( empty($this->_url) ) {
			$final_uri = '';
			// remove the ticket if present in the URL
			$final_uri = ($this->isHttps()) ? 'https' : 'http';
			$final_uri .= '://';
			/* replaced by Julien Marchal - v0.4.6
			 * $this->_url .= $_SERVER['SERVER_NAME'];
			 */
			if(empty($_SERVER['HTTP_X_FORWARDED_SERVER'])){
				/* replaced by teedog - v0.4.12
				 * $this->_url .= $_SERVER['SERVER_NAME'];
				 */
				if (empty($_SERVER['SERVER_NAME'])) {
					$server_name = $_SERVER['HTTP_HOST'];
				} else {
					$server_name = $_SERVER['SERVER_NAME'];
				}
			} else {
				$server_name = $_SERVER['HTTP_X_FORWARDED_SERVER'];
			}
			$final_uri .= $server_name;
			if (!strpos($server_name, ':')) {
				if ( ($this->isHttps() && $_SERVER['SERVER_PORT']!=443)
						|| (!$this->isHttps() && $_SERVER['SERVER_PORT']!=80) ) {
					$final_uri .= ':';
					$final_uri .= $_SERVER['SERVER_PORT'];
				}
			}
			
			$request_uri	= explode('?', $_SERVER['REQUEST_URI'], 2);
			$final_uri		.= $request_uri[0];
			
			if (isset($request_uri[1]) && $request_uri[1])
			{
				$query_string	= $this->removeParameterFromQueryString('ticket', $request_uri[1]);
				
				// If the query string still has anything left, append it to the final URI
				if ($query_string !== '')
					$final_uri	.= "?$query_string";
				
			}
			
			phpCAS::trace("Final URI: $final_uri");
			$this->setURL($final_uri);
		}
		phpCAS::traceEnd($this->_url);
		return $this->_url;
	}
	

		
	/**
	 * Removes a parameter from a query string
	 * 
	 * @param string $parameterName 
	 * @param string $queryString
	 * @return string
	 *
	 * @link http://stackoverflow.com/questions/1842681/regular-expression-to-remove-one-parameter-from-query-string
	 */
	function removeParameterFromQueryString($parameterName, $queryString)
	{
		$parameterName	= preg_quote($parameterName);
		return preg_replace("/&$parameterName(=[^&]*)?|^$parameterName(=[^&]*)?&?/", '', $queryString);
	}

	
	/**
	 * This method sets the URL of the current request 
	 *
	 * @param $url url to set for service
	 *
	 * @private
	 */
	function setURL($url)
		{
		$this->_url = $url;
		}
	
	// ########################################################################
	//  AUTHENTICATION ERROR HANDLING
	// ########################################################################
	/**
	 * This method is used to print the HTML output when the user was not authenticated.
	 *
	 * @param $failure the failure that occured
	 * @param $cas_url the URL the CAS server was asked for
	 * @param $no_response the response from the CAS server (other 
	 * parameters are ignored if TRUE)
	 * @param $bad_response bad response from the CAS server ($err_code
	 * and $err_msg ignored if TRUE)
	 * @param $cas_response the response of the CAS server
	 * @param $err_code the error code given by the CAS server
	 * @param $err_msg the error message given by the CAS server
	 *
	 * @private
	 */
	function authError($failure,$cas_url,$no_response,$bad_response='',$cas_response='',$err_code='',$err_msg='')
		{
		phpCAS::traceBegin();
		
		$this->printHTMLHeader($this->getString(CAS_STR_AUTHENTICATION_FAILED));
		printf($this->getString(CAS_STR_YOU_WERE_NOT_AUTHENTICATED),htmlentities($this->getURL()),$_SERVER['SERVER_ADMIN']);
		phpCAS::trace('CAS URL: '.$cas_url);
		phpCAS::trace('Authentication failure: '.$failure);
		if ( $no_response ) {
			phpCAS::trace('Reason: no response from the CAS server');
		} else {
			if ( $bad_response ) {
				phpCAS::trace('Reason: bad response from the CAS server');
			} else {
				switch ($this->getServerVersion()) {
					case CAS_VERSION_1_0:
						phpCAS::trace('Reason: CAS error');
						break;
					case CAS_VERSION_2_0:
						if ( empty($err_code) )
							phpCAS::trace('Reason: no CAS error');
						else
							phpCAS::trace('Reason: ['.$err_code.'] CAS error: '.$err_msg);
						break;
				}
			}
			phpCAS::trace('CAS response: '.$cas_response);
		}
		$this->printHTMLFooter();
		phpCAS::traceExit();
		exit();
		}
	
	/** @} */
}

?>
