phpldapadmin/lib/session_functions.php
2009-06-30 20:46:00 +10:00

130 lines
3.7 KiB
PHP

<?php
// $Header: /cvsroot/phpldapadmin/phpldapadmin/lib/session_functions.php,v 1.18 2007/12/15 07:50:33 wurley Exp $
/**
* A collection of functions to handle sessions throughout phpLDAPadmin.
* @author The phpLDAPadmin development team
* @package phpLDAPadmin
*/
/** The session ID that phpLDAPadmin will use for all sessions */
define('PLA_SESSION_ID','PLASESSID');
/** Enables session paranoia, which causes SIDs to change each page load (EXPERIMENTAL!) */
define('pla_session_id_paranoid', false);
/** Flag to indicate whether the session has already been initialized (this constant gets stored in $_SESSION) */
define('pla_session_id_init', 'pla_initialized');
/** The minimum first char value IP in hex for IP hashing. */
define('pla_session_id_ip_min', 8);
/** The maximum first char value of the IP in hex for IP hashing. */
define('pla_session_id_ses_max', 36);
/**
* Creates a new session id, which includes an IP hash.
*
* @return string the new session ID string
*/
function pla_session_get_id() {
if (DEBUG_ENABLED)
debug_log('pla_session_get_id(): Entered with ()',1);
$id_md5 = md5(rand(1,1000000));
$ip_md5 = md5($_SERVER['REMOTE_ADDR']);
$id_hex = hexdec($id_md5[0]) + 1;
$ip_hex = hexdec($ip_md5[0]);
if ($ip_hex <= pla_session_id_ip_min)
$ip_len = pla_session_id_ip_min;
else
$ip_len = $ip_hex - 1;
$new_id = substr($id_md5, 0, $id_hex) .
substr($ip_md5, $ip_hex, $ip_len) .
substr($id_md5, $id_hex, pla_session_id_ses_max - ($id_hex + $ip_len));
return $new_id;
}
/**
* Checks if the session belongs to an IP
*
* @return bool True, if the session is valid
*/
function pla_session_verify_id() {
if (DEBUG_ENABLED)
debug_log('pla_session_verify_id(): Entered with ()',1);
$check_id = session_id();
$ip_md5 = md5($_SERVER['REMOTE_ADDR']);
$id_hex = hexdec($check_id[0]) + 1;
$ip_hex = hexdec($ip_md5[0]);
if ($ip_hex <= pla_session_id_ip_min)
$ip_len = pla_session_id_ip_min;
else
$ip_len = $ip_hex - 1;
$ip_ses = substr($check_id, $id_hex, $ip_len);
$ip_ver = substr($ip_md5, $ip_hex, $ip_len);
return ($ip_ses == $ip_ver);
}
function pla_session_param() {
/* If cookies were disabled, build the url parameter for the session id.
It will be append to the url to be redirect */
return (SID != '') ? sprintf('&%s=%s',session_name(),session_id()) : '';
}
/**
* The only function which should be called by a user
*
* @see common.php
* @see PLA_SESSION_ID
* @return bool Returns true if the session was started the first time
*/
function pla_session_start() {
/* If session.auto_start is on in the server's PHP configuration (php.ini), then
* we will have problems loading our schema cache since the session will have started
* prior to loading the SchemaItem (and descedants) class. Destroy the auto-started
* session to prevent this problem.
*/
if (ini_get('session.auto_start'))
@session_destroy();
# Do we already have a session?
if (@session_id())
die;
@session_name(PLA_SESSION_ID);
@session_start();
# Do we have a valid session?
$is_initialized = is_array($_SESSION) && array_key_exists(pla_session_id_init,$_SESSION);
if (! $is_initialized) {
if (pla_session_id_paranoid) {
ini_set('session.use_trans_sid',0);
@session_destroy();
@session_id(pla_session_get_id());
@session_start();
ini_set('session.use_trans_sid',1);
}
$_SESSION[pla_session_id_init]['version'] = pla_version();
$_SESSION[pla_session_id_init]['config'] = filemtime(CONFDIR.'config.php');
}
@header('Cache-control: private'); // IE 6 Fix
if (pla_session_id_paranoid && ! pla_session_verify_id())
pla_error('Session inconsistent or session timeout');
return (! $is_initialized) ? true : false;
}
/**
* Stops the current session.
*/
function pla_session_close() {
@session_write_close();
}
?>