<?php

// commented in 0.4.22-RC2 for Sylvain Derosiaux
// error_reporting(E_ALL ^ E_NOTICE);

//
// hack by Vangelis Haniotakis to handle the absence of $_SERVER['REQUEST_URI'] in IIS
//
if (!$_SERVER['REQUEST_URI']) {
     $_SERVER['REQUEST_URI'] = $_SERVER['SCRIPT_NAME'].'?'.$_SERVER['QUERY_STRING'];
}

//
// another one by Vangelis Haniotakis also to make phpCAS work with PHP5
//
if (version_compare(PHP_VERSION,'5','>=')&&!function_exists("domxml_new_doc")) {
    require_once(dirname(__FILE__).'/domxml-php4-php5.php');
}

/**
 * @file CAS/CAS.php
 * Interface class of the phpCAS library
 *
 * @ingroup public
 */

// ########################################################################
//  CONSTANTS
// ########################################################################

// ------------------------------------------------------------------------
//  CAS VERSIONS
// ------------------------------------------------------------------------

/**
 * phpCAS version. accessible for the user by $this->getVersion().
 */
define('PHPCAS_VERSION','0.5.1-1');

// ------------------------------------------------------------------------
//  CAS VERSIONS
// ------------------------------------------------------------------------
/**
 * @addtogroup public
 * @{
 */

/**
 * CAS version 1.0
 */
define("CAS_VERSION_1_0",'1.0');
/*!
 * CAS version 2.0
 */
define("CAS_VERSION_2_0",'2.0');

/** @} */
/**
 * @addtogroup publicPGTStorage
 * @{
 */
// ------------------------------------------------------------------------
//  FILE PGT STORAGE
// ------------------------------------------------------------------------
/**
 * Default path used when storing PGT's to file
 */
define("CAS_PGT_STORAGE_FILE_DEFAULT_PATH",'/tmp');
/**
 * $this->setPGTStorageFile()'s 2nd parameter to write plain text files
 */
define("CAS_PGT_STORAGE_FILE_FORMAT_PLAIN",'plain');
/**
 * $this->setPGTStorageFile()'s 2nd parameter to write xml files
 */
define("CAS_PGT_STORAGE_FILE_FORMAT_XML",'xml');
/**
 * Default format used when storing PGT's to file
 */
define("CAS_PGT_STORAGE_FILE_DEFAULT_FORMAT",CAS_PGT_STORAGE_FILE_FORMAT_PLAIN);
// ------------------------------------------------------------------------
//  DATABASE PGT STORAGE
// ------------------------------------------------------------------------
/**
 * default database type when storing PGT's to database
 */
define("CAS_PGT_STORAGE_DB_DEFAULT_DATABASE_TYPE",'mysql');
/**
 * default host when storing PGT's to database
 */
define("CAS_PGT_STORAGE_DB_DEFAULT_HOSTNAME",'localhost');
/**
 * default port when storing PGT's to database
 */
define("CAS_PGT_STORAGE_DB_DEFAULT_PORT",'');
/**
 * default database when storing PGT's to database
 */
define("CAS_PGT_STORAGE_DB_DEFAULT_DATABASE",'phpCAS');
/**
 * default table when storing PGT's to database
 */
define("CAS_PGT_STORAGE_DB_DEFAULT_TABLE",'pgt');

/** @} */
// ------------------------------------------------------------------------
// SERVICE ACCESS ERRORS
// ------------------------------------------------------------------------
/**
 * @addtogroup publicServices
 * @{
 */

/**
 * $this->service() error code on success
 */
define("PHPCAS_SERVICE_OK",0);
/**
 * $this->service() error code when the PT could not retrieve because
 * the CAS server did not respond.
 */
define("PHPCAS_SERVICE_PT_NO_SERVER_RESPONSE",1);
/**
 * $this->service() error code when the PT could not retrieve because
 * the response of the CAS server was ill-formed.
 */
define("PHPCAS_SERVICE_PT_BAD_SERVER_RESPONSE",2);
/**
 * $this->service() error code when the PT could not retrieve because
 * the CAS server did not want to.
 */
define("PHPCAS_SERVICE_PT_FAILURE",3);
/**
 * $this->service() error code when the service was not available.
 */
define("PHPCAS_SERVICE_NOT AVAILABLE",4);

/** @} */
// ------------------------------------------------------------------------
//  LANGUAGES
// ------------------------------------------------------------------------
/**
 * @addtogroup publicLang
 * @{
 */

define("PHPCAS_LANG_ENGLISH",    'english');
define("PHPCAS_LANG_FRENCH",     'french');
define("PHPCAS_LANG_GREEK",      'greek');
define("PHPCAS_LANG_GERMAN",     'german');
define("PHPCAS_LANG_JAPANESE",   'japanese');

/** @} */

/**
 * @addtogroup internalLang
 * @{
 */

/**
 * phpCAS default language (when $this->setLang() is not used)
 */
define("PHPCAS_LANG_DEFAULT", PHPCAS_LANG_ENGLISH);

/** @} */
// ------------------------------------------------------------------------
//  MISC
// ------------------------------------------------------------------------
/**
 * @addtogroup internalMisc
 * @{
 */

/**
 * This global variable is used by the interface class phpCAS.
 *
 * @hideinitializer
 */
$PHPCAS_CLIENT  = null;

/**
 * This global variable is used to store where the initializer is called from 
 * (to print a comprehensive error in case of multiple calls).
 *
 * @hideinitializer
 */
$PHPCAS_INIT_CALL = array('done' => FALSE,
			  'file' => '?',
			  'line' => -1,
			  'method' => '?');

/**
 * This global variable is used to store where the method checking
 * the authentication is called from (to print comprehensive errors)
 *
 * @hideinitializer
 */
$PHPCAS_AUTH_CHECK_CALL = array('done' => FALSE,
				'file' => '?',
				'line' => -1,
				'method' => '?',
				'result' => FALSE);

/**
 * This global variable is used to store phpCAS debug mode.
 *
 * @hideinitializer
 */
$PHPCAS_DEBUG  = array('filename' => FALSE,
		       'indent' => 0,
		       'unique_id' => '');

/** @} */

// ########################################################################
//  CLIENT CLASS
// ########################################################################

// include client class
include_once(dirname(__FILE__).'/client.php');

// ########################################################################
//  INTERFACE CLASS
// ########################################################################

/**
 * @class phpCAS
 * The phpCAS class is a simple container for the phpCAS library. It provides CAS
 * authentication for web applications written in PHP.
 *
 * @ingroup public
 * @author Pascal Aubry <pascal.aubry at univ-rennes1.fr>
 *
 * \internal All its methods access the same object ($PHPCAS_CLIENT, declared 
 * at the end of CAS/client.php).
 */



class phpCAS
{

  // ########################################################################
  //  INITIALIZATION
  // ########################################################################

  /**
   * @addtogroup publicInit
   * @{
   */

  /**
   * phpCAS client initializer.
   * @note Only one of the $this->client() and $this->proxy functions should be
   * called, only once, and before all other methods (except $this->getVersion()
   * and $this->setDebug()).
   *
   * @param $server_version the version of the CAS server
   * @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 $start_session Have phpCAS start PHP sessions (default true)
   *
   * @return a newly created CASClient object
   */
  function client($server_version,
		  $server_hostname,
		  $server_port,
		  $server_uri,
 		  $start_session = true)
    {
      global $PHPCAS_CLIENT, $PHPCAS_INIT_CALL;

      $this->traceBegin();
      if ( is_object($PHPCAS_CLIENT) ) {
	$this->error($PHPCAS_INIT_CALL['method'].'() has already been called (at '.$PHPCAS_INIT_CALL['file'].':'.$PHPCAS_INIT_CALL['line'].')');
      }
      if ( gettype($server_version) != 'string' ) {
	$this->error('type mismatched for parameter $server_version (should be `string\')');
      }
      if ( gettype($server_hostname) != 'string' ) {
	$this->error('type mismatched for parameter $server_hostname (should be `string\')');
      }
      if ( gettype($server_port) != 'integer' ) {
	$this->error('type mismatched for parameter $server_port (should be `integer\')');
      }
      if ( gettype($server_uri) != 'string' ) {
	$this->error('type mismatched for parameter $server_uri (should be `string\')');
      }

      // store where the initialzer is called from
      $dbg = $this->backtrace();
      $PHPCAS_INIT_CALL = array('done' => TRUE,
				'file' => $dbg[0]['file'],
				'line' => $dbg[0]['line'],
				'method' => __CLASS__.'::'.__FUNCTION__);

      // initialize the global object $PHPCAS_CLIENT
      $PHPCAS_CLIENT = new CASClient($server_version,FALSE/*proxy*/,$server_hostname,$server_port,$server_uri,$start_session);
      $this->traceEnd();
    }

  /**
   * phpCAS proxy initializer.
   * @note Only one of the $this->client() and $this->proxy functions should be
   * called, only once, and before all other methods (except $this->getVersion()
   * and $this->setDebug()).
   *
   * @param $server_version the version of the CAS server
   * @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 $start_session Have phpCAS start PHP sessions (default true)
   *
   * @return a newly created CASClient object
   */
  function proxy($server_version,
		 $server_hostname,
		 $server_port,
		 $server_uri,
 		 $start_session = true)
    {
      global $PHPCAS_CLIENT, $PHPCAS_INIT_CALL;

      $this->traceBegin();
      if ( is_object($PHPCAS_CLIENT) ) {
	$this->error($PHPCAS_INIT_CALL['method'].'() has already been called (at '.$PHPCAS_INIT_CALL['file'].':'.$PHPCAS_INIT_CALL['line'].')');
      }
      if ( gettype($server_version) != 'string' ) {
	$this->error('type mismatched for parameter $server_version (should be `string\')');
      }
      if ( gettype($server_hostname) != 'string' ) {
	$this->error('type mismatched for parameter $server_hostname (should be `string\')');
      }
      if ( gettype($server_port) != 'integer' ) {
	$this->error('type mismatched for parameter $server_port (should be `integer\')');
      }
      if ( gettype($server_uri) != 'string' ) {
	$this->error('type mismatched for parameter $server_uri (should be `string\')');
      }

      // store where the initialzer is called from
      $dbg = $this->backtrace();
      $PHPCAS_INIT_CALL = array('done' => TRUE,
				'file' => $dbg[0]['file'],
				'line' => $dbg[0]['line'],
				'method' => __CLASS__.'::'.__FUNCTION__);

      // initialize the global object $PHPCAS_CLIENT
      $PHPCAS_CLIENT = new CASClient($server_version,TRUE/*proxy*/,$server_hostname,$server_port,$server_uri,$start_session);
      $this->traceEnd();
    }

  /** @} */
  // ########################################################################
  //  DEBUGGING
  // ########################################################################

  /**
   * @addtogroup publicDebug
   * @{
   */

  /**
   * Set/unset debug mode
   *
   * @param $filename the name of the file used for logging, or FALSE to stop debugging.
   */
  function setDebug($filename='')
    {
      global $PHPCAS_DEBUG;

      if ( $filename != FALSE && gettype($filename) != 'string' ) {
	$this->error('type mismatched for parameter $dbg (should be FALSE or the name of the log file)');
      }

      if ( empty($filename) ) {
      	if ( preg_match('/^Win.*/',getenv('OS')) ) {
      	  if ( isset($_ENV['TMP']) ) {
      	    $debugDir = $_ENV['TMP'].'/';
      	  } else if ( isset($_ENV['TEMP']) ) {
      	    $debugDir = $_ENV['TEMP'].'/';
      	  } else {
      	    $debugDir = '';
      	  }
      	} else {
      	  $debugDir = '/tmp/';
      	}
      	$filename = $debugDir . 'phpCAS.log';
      }

      if ( empty($PHPCAS_DEBUG['unique_id']) ) {
	$PHPCAS_DEBUG['unique_id'] = substr(mb_strtoupper(md5(uniqid(''))),0,4);
      }

      $PHPCAS_DEBUG['filename'] = $filename;

      $this->trace('START ******************');
    }
  
  /** @} */
  /**
   * @addtogroup internalDebug
   * @{
   */

  /**
   * This method is a wrapper for debug_backtrace() that is not available 
   * in all PHP versions (>= 4.3.0 only)
   */
  function backtrace()
    {
      if ( function_exists('debug_backtrace') ) {
        return debug_backtrace();
      } else {
        // poor man's hack ... but it does work ...
        return array();
      }
    }

  /**
   * Logs a string in debug mode.
   *
   * @param $str the string to write
   *
   * @private
   */
  function log($str)
    {
      $indent_str = ".";
      global $PHPCAS_DEBUG;

      if ( $PHPCAS_DEBUG['filename'] ) {
	for ($i=0;$i<$PHPCAS_DEBUG['indent'];$i++) {
	  $indent_str .= '|    ';
	}
	error_log($PHPCAS_DEBUG['unique_id'].' '.$indent_str.$str."\n",3,$PHPCAS_DEBUG['filename']);
      }

    }
  
  /**
   * This method is used by interface methods to print an error and where the function
   * was originally called from.
   *
   * @param $msg the message to print
   *
   * @private
   */
  function error($msg)
    {
      $dbg = $this->backtrace();
      $function = '?';
      $file = '?';
      $line = '?';
      if ( is_array($dbg) ) {
	for ( $i=1; $i<sizeof($dbg); $i++) {
	  if ( is_array($dbg[$i]) ) {
	    if ( $dbg[$i]['class'] == __CLASS__ ) {
	      $function = $dbg[$i]['function'];
	      $file = $dbg[$i]['file'];
	      $line = $dbg[$i]['line'];
	    }
	  }
	}
      }
      echo "<br />\n<b>phpCAS error</b>: <font color=\"FF0000\"><b>".__CLASS__."::".$function.'(): '.htmlentities($msg,ENT_COMPAT | ENT_HTML401,"UTF-8")."</b></font> in <b>".$file."</b> on line <b>".$line."</b><br />\n";
      $this->trace($msg);
      $this->traceExit();
      exit();
    }

  /**
   * This method is used to log something in debug mode.
   */
  function trace($str)
    {
      $dbg = $this->backtrace();
      $this->log($str.' ['.basename($dbg[1]['file']).':'.$dbg[1]['line'].']');
    }

  /**
   * This method is used to indicate the start of the execution of a function in debug mode.
   */
  function traceBegin()
    {
      global $PHPCAS_DEBUG;

      $dbg = $this->backtrace();
      $str = '=> ';
      if ( !empty($dbg[2]['class']) ) {
	$str .= $dbg[2]['class'].'::';
      }
      $str .= $dbg[2]['function'].'(';      
      if ( is_array($dbg[2]['args']) ) {
	foreach ($dbg[2]['args'] as $index => $arg) {
	  if ( $index != 0 ) {
	    $str .= ', ';
	  }
	  $str .= str_replace("\n","",var_export($arg,TRUE));
	}
      }
      $str .= ') ['.basename($dbg[2]['file']).':'.$dbg[2]['line'].']';
      $this->log($str);
      $PHPCAS_DEBUG['indent'] ++;
    }

  /**
   * This method is used to indicate the end of the execution of a function in debug mode.
   *
   * @param $res the result of the function
   */
  function traceEnd($res='')
    {
      global $PHPCAS_DEBUG;

      $PHPCAS_DEBUG['indent'] --;
      $dbg = $this->backtrace();
      $str = '';
      $str .= '<= '.str_replace("\n","",var_export($res,TRUE));
      $this->log($str);
    }

  /**
   * This method is used to indicate the end of the execution of the program
   */
  function traceExit()
    {
      global $PHPCAS_DEBUG;

      $this->log('exit()');
      while ( $PHPCAS_DEBUG['indent'] > 0 ) {
	$this->log('-');
	$PHPCAS_DEBUG['indent'] --;
      }
    }

  /** @} */
  // ########################################################################
  //  INTERNATIONALIZATION
  // ########################################################################
  /**
   * @addtogroup publicLang
   * @{
   */

  /**
   * This method is used to set the language used by phpCAS. 
   * @note Can be called only once.
   *
   * @param $lang a string representing the language.
   *
   * @sa PHPCAS_LANG_FRENCH, PHPCAS_LANG_ENGLISH
   */
  function setLang($lang)
    {
      global $PHPCAS_CLIENT;
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      if ( gettype($lang) != 'string' ) {
	$this->error('type mismatched for parameter $lang (should be `string\')');
      }
      $PHPCAS_CLIENT->setLang($lang);
    }

  /** @} */
  // ########################################################################
  //  VERSION
  // ########################################################################
  /**
   * @addtogroup public
   * @{
   */

  /**
   * This method returns the phpCAS version.
   *
   * @return the phpCAS version.
   */
  function getVersion()
    {
      return PHPCAS_VERSION;
    }
  
  /** @} */
  // ########################################################################
  //  HTML OUTPUT
  // ########################################################################
  /**
   * @addtogroup publicOutput
   * @{
   */

  /**
   * This method sets the HTML header used for all outputs.
   *
   * @param $header the HTML header.
   */
  function setHTMLHeader($header)
    {
      global $PHPCAS_CLIENT;
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      if ( gettype($header) != 'string' ) {
	$this->error('type mismatched for parameter $header (should be `string\')');
      }
      $PHPCAS_CLIENT->setHTMLHeader($header);
    }

  /**
   * This method sets the HTML footer used for all outputs.
   *
   * @param $footer the HTML footer.
   */
  function setHTMLFooter($footer)
    {
      global $PHPCAS_CLIENT;
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      if ( gettype($footer) != 'string' ) {
	$this->error('type mismatched for parameter $footer (should be `string\')');
      }
      $PHPCAS_CLIENT->setHTMLFooter($footer);
    }

  /** @} */
  // ########################################################################
  //  PGT STORAGE
  // ########################################################################
  /**
   * @addtogroup publicPGTStorage
   * @{
   */

  /**
   * 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 $path the path where the PGT's should be stored
   */
  function setPGTStorageFile($format='',
			     $path='')
    {
      global $PHPCAS_CLIENT,$PHPCAS_AUTH_CHECK_CALL;

      $this->traceBegin();
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should only be called after '.__CLASS__.'::proxy()');
      }
      if ( !$PHPCAS_CLIENT->isProxy() ) {
	$this->error('this method should only be called after '.__CLASS__.'::proxy()');
      }
      if ( $PHPCAS_AUTH_CHECK_CALL['done'] ) {
	$this->error('this method should only be called before '.$PHPCAS_AUTH_CHECK_CALL['method'].'() (called at '.$PHPCAS_AUTH_CHECK_CALL['file'].':'.$PHPCAS_AUTH_CHECK_CALL['line'].')');
      }
      if ( gettype($format) != 'string' ) {
	$this->error('type mismatched for parameter $format (should be `string\')');
      }
      if ( gettype($path) != 'string' ) {
	$this->error('type mismatched for parameter $format (should be `string\')');
      }
      $PHPCAS_CLIENT->setPGTStorageFile($format,$path);
      $this->traceEnd();
    }
  
  /**
   * 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, except in debug mode.
   *
   * @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 $table the name of the table storing the data
   */
  function setPGTStorageDB($user,
			   $password,
			   $database_type='',
			   $hostname='',
			   $port=0,
			   $database='',
			   $table='')
    {
      global $PHPCAS_CLIENT,$PHPCAS_AUTH_CHECK_CALL;

      $this->traceBegin();
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should only be called after '.__CLASS__.'::proxy()');
      }
      if ( !$PHPCAS_CLIENT->isProxy() ) {
	$this->error('this method should only be called after '.__CLASS__.'::proxy()');
      }
      if ( $PHPCAS_AUTH_CHECK_CALL['done'] ) {
	$this->error('this method should only be called before '.$PHPCAS_AUTH_CHECK_CALL['method'].'() (called at '.$PHPCAS_AUTH_CHECK_CALL['file'].':'.$PHPCAS_AUTH_CHECK_CALL['line'].')');
      }
      if ( gettype($user) != 'string' ) {
	$this->error('type mismatched for parameter $user (should be `string\')');
      }
      if ( gettype($password) != 'string' ) {
	$this->error('type mismatched for parameter $password (should be `string\')');
      }
      if ( gettype($database_type) != 'string' ) {
	$this->error('type mismatched for parameter $database_type (should be `string\')');
      }
      if ( gettype($hostname) != 'string' ) {
	$this->error('type mismatched for parameter $hostname (should be `string\')');
      }
      if ( gettype($port) != 'integer' ) {
	$this->error('type mismatched for parameter $port (should be `integer\')');
      }
      if ( gettype($database) != 'string' ) {
	$this->error('type mismatched for parameter $database (should be `string\')');
      }
      if ( gettype($table) != 'string' ) {
	$this->error('type mismatched for parameter $table (should be `string\')');
      }
      $PHPCAS_CLIENT->setPGTStorageDB($this,$user,$password,$hostname,$port,$database,$table);
      $this->traceEnd();
    }
  
  /** @} */
  // ########################################################################
  // ACCESS TO EXTERNAL SERVICES
  // ########################################################################
  /**
   * @addtogroup publicServices
   * @{
   */

  /**
   * 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 $output contains an error message).
   */
  function serviceWeb($url,&$err_code,&$output)
    {
      global $PHPCAS_CLIENT, $PHPCAS_AUTH_CHECK_CALL;

      $this->traceBegin();
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should only be called after '.__CLASS__.'::proxy()');
      }
      if ( !$PHPCAS_CLIENT->isProxy() ) {
	$this->error('this method should only be called after '.__CLASS__.'::proxy()');
      }
      if ( !$PHPCAS_AUTH_CHECK_CALL['done'] ) {
	$this->error('this method should only be called after the programmer is sure the user has been authenticated (by calling '.__CLASS__.'::checkAuthentication() or '.__CLASS__.'::forceAuthentication()');
      }
      if ( !$PHPCAS_AUTH_CHECK_CALL['result'] ) {
	$this->error('authentication was checked (by '.$PHPCAS_AUTH_CHECK_CALL['method'].'() at '.$PHPCAS_AUTH_CHECK_CALL['file'].':'.$PHPCAS_AUTH_CHECK_CALL['line'].') but the method returned FALSE');
      }
      if ( gettype($url) != 'string' ) {
	$this->error('type mismatched for parameter $url (should be `string\')');
      }
      
      $res = $PHPCAS_CLIENT->serviceWeb($url,$err_code,$output);

      $this->traceEnd($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 $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 $err_msg contains an error message).
   */
  function serviceMail($url,$flags,&$err_code,&$err_msg,&$pt)
    {
      global $PHPCAS_CLIENT, $PHPCAS_AUTH_CHECK_CALL;

      $this->traceBegin();
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should only be called after '.__CLASS__.'::proxy()');
      }
      if ( !$PHPCAS_CLIENT->isProxy() ) {
	$this->error('this method should only be called after '.__CLASS__.'::proxy()');
      }
      if ( !$PHPCAS_AUTH_CHECK_CALL['done'] ) {
	$this->error('this method should only be called after the programmer is sure the user has been authenticated (by calling '.__CLASS__.'::checkAuthentication() or '.__CLASS__.'::forceAuthentication()');
      }
      if ( !$PHPCAS_AUTH_CHECK_CALL['result'] ) {
	$this->error('authentication was checked (by '.$PHPCAS_AUTH_CHECK_CALL['method'].'() at '.$PHPCAS_AUTH_CHECK_CALL['file'].':'.$PHPCAS_AUTH_CHECK_CALL['line'].') but the method returned FALSE');
      }
      if ( gettype($url) != 'string' ) {
	$this->error('type mismatched for parameter $url (should be `string\')');
      }
      
      if ( gettype($flags) != 'integer' ) {
	$this->error('type mismatched for parameter $flags (should be `integer\')');
      }
      
      $res = $PHPCAS_CLIENT->serviceMail($url,$flags,$err_code,$err_msg,$pt);

      $this->traceEnd($res);
      return $res;
    }

  /** @} */
  // ########################################################################
  //  AUTHENTICATION
  // ########################################################################
  /**
   * @addtogroup publicAuth
   * @{
   */

  /**
   * Set the times authentication will be cached before really accessing the CAS server in gateway mode: 
   * - -1: check only once, and then never again (until you pree login)
   * - 0: always check
   * - n: check every "n" time
   *
   * @param $n an integer.
   */
  function setCacheTimesForAuthRecheck($n)
    {
      global $PHPCAS_CLIENT;
      if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      if ( gettype($header) != 'integer' ) {
        $this->error('type mismatched for parameter $header (should be `string\')');
      }
      $PHPCAS_CLIENT->setCacheTimesForAuthRecheck($n);
    }
  
  /**
   * This method is called to check if the user is authenticated (use the gateway feature).
   * @return TRUE when the user is authenticated; otherwise FALSE.
   */
  function checkAuthentication()
    {
      global $PHPCAS_CLIENT, $PHPCAS_AUTH_CHECK_CALL;

      $this->traceBegin();
      if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }

      $auth = $PHPCAS_CLIENT->checkAuthentication();

      // store where the authentication has been checked and the result
      $dbg = $this->backtrace();
      $PHPCAS_AUTH_CHECK_CALL = array('done' => TRUE,
				      'file' => $dbg[0]['file'],
				      'line' => $dbg[0]['line'],
				      'method' => __CLASS__.'::'.__FUNCTION__,
				      'result' => $auth );
      $this->traceEnd($auth);
      return $auth; 
    }
  
  /**
   * This method is called to force authentication if the user was not already 
   * authenticated. If the user is not authenticated, halt by redirecting to 
   * the CAS server.
   */
  function forceAuthentication()
    {
      global $PHPCAS_CLIENT, $PHPCAS_AUTH_CHECK_CALL;

      $this->traceBegin();
      if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      
      $auth = $PHPCAS_CLIENT->forceAuthentication();

      // store where the authentication has been checked and the result
      $dbg = $this->backtrace();
      $PHPCAS_AUTH_CHECK_CALL = array('done' => TRUE,
				      'file' => $dbg[0]['file'],
				      'line' => $dbg[0]['line'],
				      'method' => __CLASS__.'::'.__FUNCTION__,
				      'result' => $auth );

      if ( !$auth ) {
        $this->trace('user is not authenticated, redirecting to the CAS server');
        $PHPCAS_CLIENT->forceAuthentication();
      } else {
        $this->trace('no need to authenticate (user `'.$this->getUser().'\' is already authenticated)');
      }

      $this->traceEnd();
      return $auth; 
    }
  
  /**
   * This method has been left from version 0.4.1 for compatibility reasons.
   */
  function authenticate()
    {
      $this->error('this method is deprecated. You should use '.__CLASS__.'::forceAuthentication() instead');
    }
  
  /**
   * 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.
   */
  function isAuthenticated()
    {
      global $PHPCAS_CLIENT, $PHPCAS_AUTH_CHECK_CALL;

      $this->traceBegin();
      if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }

      // call the isAuthenticated method of the global $PHPCAS_CLIENT object
      $auth = $PHPCAS_CLIENT->isAuthenticated();

      // store where the authentication has been checked and the result
      $dbg = $this->backtrace();
      $PHPCAS_AUTH_CHECK_CALL = array('done' => TRUE,
                                     'file' => $dbg[0]['file'],
                                     'line' => $dbg[0]['line'],
                                     'method' => __CLASS__.'::'.__FUNCTION__,
                                     'result' => $auth );
      $this->traceEnd($auth);
      return $auth;
    }
  
  /**
   * Checks whether authenticated based on $_SESSION. Useful to avoid
   * server calls.
   * @return true if authenticated, false otherwise.
   * @since 0.4.22 by Brendan Arnold
   */
  function isSessionAuthenticated ()
	{
      global $PHPCAS_CLIENT;
      if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      return($PHPCAS_CLIENT->isSessionAuthenticated());
    }

  /**
   * This method returns the CAS user's login name.
   * @warning should not be called only after $this->forceAuthentication()
   * or $this->checkAuthentication().
   *
   * @return the login name of the authenticated user
   */
  function getUser()
    {
      global $PHPCAS_CLIENT, $PHPCAS_AUTH_CHECK_CALL;
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      if ( !$PHPCAS_AUTH_CHECK_CALL['done'] ) {
	$this->error('this method should only be called after '.__CLASS__.'::forceAuthentication() or '.__CLASS__.'::isAuthenticated()');
      }
      if ( !$PHPCAS_AUTH_CHECK_CALL['result'] ) {
	$this->error('authentication was checked (by '.$PHPCAS_AUTH_CHECK_CALL['method'].'() at '.$PHPCAS_AUTH_CHECK_CALL['file'].':'.$PHPCAS_AUTH_CHECK_CALL['line'].') but the method returned FALSE');
      }
      return $PHPCAS_CLIENT->getUser();
    }

  /**
   * This method returns the URL to be used to login.
   * or $this->isAuthenticated().
   *
   * @return the login name of the authenticated user
   */
  function getServerLoginURL()
    {
      global $PHPCAS_CLIENT;
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      return $PHPCAS_CLIENT->getServerLoginURL();
    }

  /**
   * Set the login URL of the CAS server.
   * @param $url the login URL
   * @since 0.4.21 by Wyman Chan
   */
  function setServerLoginURL($url='')
   {
     global $PHPCAS_CLIENT;
     $this->traceBegin();
     if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should only be called after
'.__CLASS__.'::client()');
     }
     if ( gettype($url) != 'string' ) {
        $this->error('type mismatched for parameter $url (should be
`string\')');
     }
     $PHPCAS_CLIENT->setServerLoginURL($url);
     $this->traceEnd();
   }

  /**
   * This method returns the URL to be used to login.
   * or $this->isAuthenticated().
   *
   * @return the login name of the authenticated user
   */
  function getServerLogoutURL()
    {
      global $PHPCAS_CLIENT;
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should not be called before '.__CLASS__.'::client() or '.__CLASS__.'::proxy()');
      }
      return $PHPCAS_CLIENT->getServerLogoutURL();
    }

  /**
   * Set the logout URL of the CAS server.
   * @param $url the logout URL
   * @since 0.4.21 by Wyman Chan
   */
  function setServerLogoutURL($url='')
   {
     global $PHPCAS_CLIENT;
     $this->traceBegin();
     if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should only be called after
'.__CLASS__.'::client()');
     }
     if ( gettype($url) != 'string' ) {
        $this->error('type mismatched for parameter $url (should be
`string\')');
     }
     $PHPCAS_CLIENT->setServerLogoutURL($url);
     $this->traceEnd();
   }

  /**
   * This method is used to logout from CAS. Halts by redirecting to the CAS server.
   * @param $url a URL that will be transmitted to the CAS server (to come back to when logged out)
   */
  function logout($url = "")
    {
      global $PHPCAS_CLIENT;

      $this->traceBegin();
      if ( !is_object($PHPCAS_CLIENT) ) {
	$this->error('this method should only be called after '.__CLASS__.'::client() or'.__CLASS__.'::proxy()');
      }
      $PHPCAS_CLIENT->logout($url);
      // never reached
      $this->traceEnd();
    }

  /**
   * Set the fixed URL that will be used by the CAS server to transmit the PGT.
   * When this method is not called, a phpCAS script uses its own URL for the callback.
   *
   * @param $url the URL
   */
  function setFixedCallbackURL($url='')
   {
     global $PHPCAS_CLIENT;
     $this->traceBegin();
     if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should only be called after '.__CLASS__.'::proxy()');
     }
     if ( !$PHPCAS_CLIENT->isProxy() ) {
        $this->error('this method should only be called after '.__CLASS__.'::proxy()');
     }
     if ( gettype($url) != 'string' ) {
        $this->error('type mismatched for parameter $url (should be `string\')');
     }
     $PHPCAS_CLIENT->setCallbackURL($url);
     $this->traceEnd();
   }
   
  /**
   * Set the fixed URL that will be set as the CAS service parameter. When this
   * method is not called, a phpCAS script uses its own URL.
   *
   * @param $url the URL
   */
   function setFixedServiceURL($url)
   {
     global $PHPCAS_CLIENT;
     $this->traceBegin();
     if ( !is_object($PHPCAS_CLIENT) ) {
         $this->error('this method should only be called after '.__CLASS__.'::proxy()');
     }  
     if ( gettype($url) != 'string' ) {
        $this->error('type mismatched for parameter $url (should be `string\')');
     }
     $PHPCAS_CLIENT->setURL($url);
     $this->traceEnd();
   }

  /**
   * Get the URL that is set as the CAS service parameter.
   */
   function getServiceURL()
   {
     global $PHPCAS_CLIENT;
     if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should only be called after '.__CLASS__.'::proxy()');
     }  
     return($PHPCAS_CLIENT->getURL());
   }

  /**
   * Retrieve a Proxy Ticket from the CAS server.
   */
   function retrievePT($target_service,&$err_code,&$err_msg)
   {
     global $PHPCAS_CLIENT;
     if ( !is_object($PHPCAS_CLIENT) ) {
        $this->error('this method should only be called after '.__CLASS__.'::proxy()');
     }  
     if ( gettype($target_service) != 'string' ) {
        $this->error('type mismatched for parameter $target_service(should be `string\')');
     }
     return($PHPCAS_CLIENT->retrievePT($target_service,$err_code,$err_msg));
   }
  /** @} */

}

// ########################################################################
// DOCUMENTATION
// ########################################################################

// ########################################################################
//  MAIN PAGE

/**
 * @mainpage
 *
 * The following pages only show the source documentation.
 *
 * For more information on phpCAS, please refer to http://esup-phpcas.sourceforge.net
 *
 */

// ########################################################################
//  MODULES DEFINITION

/** @defgroup public User interface */

/** @defgroup publicInit Initialization
 *  @ingroup public */

/** @defgroup publicAuth Authentication
 *  @ingroup public */

/** @defgroup publicServices Access to external services
 *  @ingroup public */

/** @defgroup publicConfig Configuration
 *  @ingroup public */

/** @defgroup publicLang Internationalization
 *  @ingroup publicConfig */

/** @defgroup publicOutput HTML output
 *  @ingroup publicConfig */

/** @defgroup publicPGTStorage PGT storage
 *  @ingroup publicConfig */

/** @defgroup publicDebug Debugging
 *  @ingroup public */


/** @defgroup internal Implementation */

/** @defgroup internalAuthentication Authentication
 *  @ingroup internal */

/** @defgroup internalBasic CAS Basic client features (CAS 1.0, Service Tickets)
 *  @ingroup internal */

/** @defgroup internalProxy CAS Proxy features (CAS 2.0, Proxy Granting Tickets)
 *  @ingroup internal */

/** @defgroup internalPGTStorage PGT storage
 *  @ingroup internalProxy */

/** @defgroup internalPGTStorageDB PGT storage in a database
 *  @ingroup internalPGTStorage */

/** @defgroup internalPGTStorageFile PGT storage on the filesystem
 *  @ingroup internalPGTStorage */

/** @defgroup internalCallback Callback from the CAS server
 *  @ingroup internalProxy */

/** @defgroup internalProxied CAS proxied client features (CAS 2.0, Proxy Tickets)
 *  @ingroup internal */

/** @defgroup internalConfig Configuration
 *  @ingroup internal */

/** @defgroup internalOutput HTML output
 *  @ingroup internalConfig */

/** @defgroup internalLang Internationalization
 *  @ingroup internalConfig
 *
 * To add a new language:
 * - 1. define a new constant PHPCAS_LANG_XXXXXX in CAS/CAS.php
 * - 2. copy any file from CAS/languages to CAS/languages/XXXXXX.php
 * - 3. Make the translations
 */

/** @defgroup internalDebug Debugging
 *  @ingroup internal */

/** @defgroup internalMisc Miscellaneous
 *  @ingroup internal */

// ########################################################################
//  EXAMPLES

/**
 * @example example_simple.php
 */
/**
 * @example example_proxy.php
 */
/**
 * @example example_proxy2.php
 */
/**
 * @example example_lang.php
 */
/**
 * @example example_html.php
 */
/**
 * @example example_file.php
 */
/**
 * @example example_db.php
 */
/**
 * @example example_service.php
 */
/**
 * @example example_session_proxy.php
 */
/**
 * @example example_session_service.php
 */
/**
 * @example example_gateway.php
 */



?>
