File Source for session.php

<?php
/**
* @package Joomla.Platform
* @subpackage Session
*
* @copyright Copyright (C) 2005 - 2013 Open Source Matters, Inc. All rights reserved.
* @license GNU General Public License version 2 or later; see LICENSE
*/
defined('JPATH_PLATFORM') or die;
/**
* Class for managing HTTP sessions
*
* Provides access to session-state values as well as session-level
* settings and lifetime management methods.
* Based on the standard PHP session handling mechanism it provides
* more advanced features such as expire timeouts.
*
* @package Joomla.Platform
* @subpackage Session
* @since 11.1
*/
class JSession implements IteratorAggregate
{
/**
* Internal state.
* One of 'inactive'|'active'|'expired'|'destroyed'|'error'
*
* @var string
* @see JSession::getState()
* @since 11.1
*/
protected $_state = 'inactive';
/**
* Maximum age of unused session in minutes
*
* @var string
* @since 11.1
*/
protected $_expire = 15;
/**
* The session store object.
*
* @var JSessionStorage
* @since 11.1
*/
protected $_store = null;
/**
* Security policy.
* List of checks that will be done.
*
* Default values:
* - fix_browser
* - fix_adress
*
* @var array
* @since 11.1
*/
protected $_security = array('fix_browser');
/**
* Force cookies to be SSL only
* Default false
*
* @var boolean
* @since 11.1
*/
protected $_force_ssl = false;
/**
* JSession instances container.
*
* @var JSession
* @since 11.3
*/
protected static $instance;
/**
* The type of storage for the session.
*
* @var string
* @since 12.2
*/
protected $storeName;
/**
* Holds the JInput object
*
* @var JInput
* @since 12.2
*/
private $_input = null;
/**
* Holds the event dispatcher object
*
* @var JEventDispatcher
* @since 12.2
*/
private $_dispatcher = null;
/**
* Constructor
*
* @param string $store The type of storage for the session.
* @param array $options Optional parameters
*
* @since 11.1
*/
public function __construct($store = 'none', array $options = array())
{
// Need to destroy any existing sessions started with session.auto_start
if (session_id())
{
session_unset();
session_destroy();
}
// Disable transparent sid support
ini_set('session.use_trans_sid', '0');
// Only allow the session ID to come from cookies and nothing else.
ini_set('session.use_only_cookies', '1');
// Create handler
$this->_store = JSessionStorage::getInstance($store, $options);
$this->storeName = $store;
// Set options
$this->_setOptions($options);
$this->_setCookieParams();
$this->_state = 'inactive';
}
/**
* Magic method to get read-only access to properties.
*
* @param string $name Name of property to retrieve
*
* @return mixed The value of the property
*
* @since 12.2
*/
public function __get($name)
{
if ($name === 'storeName')
{
return $this->$name;
}
if ($name === 'state' || $name === 'expire')
{
$property = '_' . $name;
return $this->$property;
}
}
/**
* Returns the global Session object, only creating it
* if it doesn't already exist.
*
* @param string $handler The type of session handler.
* @param array $options An array of configuration options.
*
* @return JSession The Session object.
*
* @since 11.1
*/
public static function getInstance($handler, $options)
{
if (!is_object(self::$instance))
{
self::$instance = new JSession($handler, $options);
}
return self::$instance;
}
/**
* Get current state of session
*
* @return string The session state
*
* @since 11.1
*/
public function getState()
{
return $this->_state;
}
/**
* Get expiration time in minutes
*
* @return integer The session expiration time in minutes
*
* @since 11.1
*/
public function getExpire()
{
return $this->_expire;
}
/**
* Get a session token, if a token isn't set yet one will be generated.
*
* Tokens are used to secure forms from spamming attacks. Once a token
* has been generated the system will check the post request to see if
* it is present, if not it will invalidate the session.
*
* @param boolean $forceNew If true, force a new token to be created
*
* @return string The session token
*
* @since 11.1
*/
public function getToken($forceNew = false)
{
$token = $this->get('session.token');
// Create a token
if ($token === null || $forceNew)
{
$token = $this->_createToken(12);
$this->set('session.token', $token);
}
return $token;
}
/**
* Method to determine if a token exists in the session. If not the
* session will be set to expired
*
* @param string $tCheck Hashed token to be verified
* @param boolean $forceExpire If true, expires the session
*
* @return boolean
*
* @since 11.1
*/
public function hasToken($tCheck, $forceExpire = true)
{
// Check if a token exists in the session
$tStored = $this->get('session.token');
// Check token
if (($tStored !== $tCheck))
{
if ($forceExpire)
{
$this->_state = 'expired';
}
return false;
}
return true;
}
/**
* Method to determine a hash for anti-spoofing variable names
*
* @param boolean $forceNew If true, force a new token to be created
*
* @return string Hashed var name
*
* @since 11.1
*/
public static function getFormToken($forceNew = false)
{
$user = JFactory::getUser();
$session = JFactory::getSession();
// TODO: Decouple from legacy JApplication class.
if (is_callable(array('JApplication', 'getHash')))
{
$hash = JApplication::getHash($user->get('id', 0) . $session->getToken($forceNew));
}
else
{
$hash = md5(JFactory::getApplication()->get('secret') . $user->get('id', 0) . $session->getToken($forceNew));
}
return $hash;
}
/**
* Retrieve an external iterator.
*
* @return ArrayIterator Return an ArrayIterator of $_SESSION.
*
* @since 12.2
*/
public function getIterator()
{
return new ArrayIterator($_SESSION);
}
/**
* Checks for a form token in the request.
*
* Use in conjunction with JHtml::_('form.token') or JSession::getFormToken.
*
* @param string $method The request method in which to look for the token key.
*
* @return boolean True if found and valid, false otherwise.
*
* @since 12.1
*/
public static function checkToken($method = 'post')
{
$token = self::getFormToken();
$app = JFactory::getApplication();
if (!$app->input->$method->get($token, '', 'alnum'))
{
$session = JFactory::getSession();
if ($session->isNew())
{
// Redirect to login screen.
$app->enqueueMessage(JText::_('JLIB_ENVIRONMENT_SESSION_EXPIRED'), 'warning');
$app->redirect(JRoute::_('index.php'));
}
else
{
return false;
}
}
else
{
return true;
}
}
/**
* Get session name
*
* @return string The session name
*
* @since 11.1
*/
public function getName()
{
if ($this->_state === 'destroyed')
{
// @TODO : raise error
return null;
}
return session_name();
}
/**
* Get session id
*
* @return string The session name
*
* @since 11.1
*/
public function getId()
{
if ($this->_state === 'destroyed')
{
// @TODO : raise error
return null;
}
return session_id();
}
/**
* Get the session handlers
*
* @return array An array of available session handlers
*
* @since 11.1
*/
public static function getStores()
{
$connectors = array();
// Get an iterator and loop trough the driver classes.
$iterator = new DirectoryIterator(__DIR__ . '/storage');
foreach ($iterator as $file)
{
$fileName = $file->getFilename();
// Only load for php files.
// Note: DirectoryIterator::getExtension only available PHP >= 5.3.6
if (!$file->isFile() || substr($fileName, strrpos($fileName, '.') + 1) != 'php')
{
continue;
}
// Derive the class name from the type.
$class = str_ireplace('.php', '', 'JSessionStorage' . ucfirst(trim($fileName)));
// If the class doesn't exist we have nothing left to do but look at the next type. We did our best.
if (!class_exists($class))
{
continue;
}
// Sweet! Our class exists, so now we just need to know if it passes its test method.
if ($class::isSupported())
{
// Connector names should not have file extensions.
$connectors[] = str_ireplace('.php', '', $fileName);
}
}
return $connectors;
}
/**
* Shorthand to check if the session is active
*
* @return boolean
*
* @since 12.2
*/
public function isActive()
{
return (bool) ($this->_state == 'active');
}
/**
* Check whether this session is currently created
*
* @return boolean True on success.
*
* @since 11.1
*/
public function isNew()
{
$counter = $this->get('session.counter');
return (bool) ($counter === 1);
}
/**
* Check whether this session is currently created
*
* @param JInput $input JInput object for the session to use.
* @param JEventDispatcher $dispatcher Dispatcher object for the session to use.
*
* @return void.
*
* @since 12.2
*/
public function initialise(JInput $input, JEventDispatcher $dispatcher = null)
{
$this->_input = $input;
$this->_dispatcher = $dispatcher;
}
/**
* Get data from the session store
*
* @param string $name Name of a variable
* @param mixed $default Default value of a variable if not set
* @param string $namespace Namespace to use, default to 'default'
*
* @return mixed Value of a variable
*
* @since 11.1
*/
public function get($name, $default = null, $namespace = 'default')
{
// Add prefix to namespace to avoid collisions
$namespace = '__' . $namespace;
if ($this->_state !== 'active' && $this->_state !== 'expired')
{
// @TODO :: generated error here
$error = null;
return $error;
}
if (isset($_SESSION[$namespace][$name]))
{
return $_SESSION[$namespace][$name];
}
return $default;
}
/**
* Set data into the session store.
*
* @param string $name Name of a variable.
* @param mixed $value Value of a variable.
* @param string $namespace Namespace to use, default to 'default'.
*
* @return mixed Old value of a variable.
*
* @since 11.1
*/
public function set($name, $value = null, $namespace = 'default')
{
// Add prefix to namespace to avoid collisions
$namespace = '__' . $namespace;
if ($this->_state !== 'active')
{
// @TODO :: generated error here
return null;
}
$old = isset($_SESSION[$namespace][$name]) ? $_SESSION[$namespace][$name] : null;
if (null === $value)
{
unset($_SESSION[$namespace][$name]);
}
else
{
$_SESSION[$namespace][$name] = $value;
}
return $old;
}
/**
* Check whether data exists in the session store
*
* @param string $name Name of variable
* @param string $namespace Namespace to use, default to 'default'
*
* @return boolean True if the variable exists
*
* @since 11.1
*/
public function has($name, $namespace = 'default')
{
// Add prefix to namespace to avoid collisions.
$namespace = '__' . $namespace;
if ($this->_state !== 'active')
{
// @TODO :: generated error here
return null;
}
return isset($_SESSION[$namespace][$name]);
}
/**
* Unset data from the session store
*
* @param string $name Name of variable
* @param string $namespace Namespace to use, default to 'default'
*
* @return mixed The value from session or NULL if not set
*
* @since 11.1
*/
public function clear($name, $namespace = 'default')
{
// Add prefix to namespace to avoid collisions
$namespace = '__' . $namespace;
if ($this->_state !== 'active')
{
// @TODO :: generated error here
return null;
}
$value = null;
if (isset($_SESSION[$namespace][$name]))
{
$value = $_SESSION[$namespace][$name];
unset($_SESSION[$namespace][$name]);
}
return $value;
}
/**
* Start a session.
*
* @return void
*
* @since 12.2
*/
public function start()
{
if ($this->_state === 'active')
{
return;
}
$this->_start();
$this->_state = 'active';
// Initialise the session
$this->_setCounter();
$this->_setTimers();
// Perform security checks
$this->_validate();
if ($this->_dispatcher instanceof JEventDispatcher)
{
$this->_dispatcher->trigger('onAfterSessionStart');
}
}
/**
* Start a session.
*
* Creates a session (or resumes the current one based on the state of the session)
*
* @return boolean true on success
*
* @since 11.1
*/
protected function _start()
{
// Start session if not started
if ($this->_state === 'restart')
{
session_regenerate_id(true);
}
else
{
$session_name = session_name();
// Get the JInputCookie object
$cookie = $this->_input->cookie;
if (is_null($cookie->get($session_name)))
{
$session_clean = $this->_input->get($session_name, false, 'string');
if ($session_clean)
{
session_id($session_clean);
$cookie->set($session_name, '', time() - 3600);
}
}
}
/**
* Write and Close handlers are called after destructing objects since PHP 5.0.5.
* Thus destructors can use sessions but session handler can't use objects.
* So we are moving session closure before destructing objects.
*
* Replace with session_register_shutdown() when dropping compatibility with PHP 5.3
*/
register_shutdown_function('session_write_close');
session_cache_limiter('none');
session_start();
return true;
}
/**
* Frees all session variables and destroys all data registered to a session
*
* This method resets the $_SESSION variable and destroys all of the data associated
* with the current session in its storage (file or DB). It forces new session to be
* started after this method is called. It does not unset the session cookie.
*
* @return boolean True on success
*
* @see session_destroy()
* @see session_unset()
* @since 11.1
*/
public function destroy()
{
// Session was already destroyed
if ($this->_state === 'destroyed')
{
return true;
}
/*
* In order to kill the session altogether, such as to log the user out, the session id
* must also be unset. If a cookie is used to propagate the session id (default behavior),
* then the session cookie must be deleted.
*/
if (isset($_COOKIE[session_name()]))
{
$config = JFactory::getConfig();
$cookie_domain = $config->get('cookie_domain', '');
$cookie_path = $config->get('cookie_path', '/');
setcookie(session_name(), '', time() - 42000, $cookie_path, $cookie_domain);
}
session_unset();
session_destroy();
$this->_state = 'destroyed';
return true;
}
/**
* Restart an expired or locked session.
*
* @return boolean True on success
*
* @see JSession::destroy()
* @since 11.1
*/
public function restart()
{
$this->destroy();
if ($this->_state !== 'destroyed')
{
// @TODO :: generated error here
return false;
}
// Re-register the session handler after a session has been destroyed, to avoid PHP bug
$this->_store->register();
$this->_state = 'restart';
// Regenerate session id
session_regenerate_id(true);
$this->_start();
$this->_state = 'active';
$this->_validate();
$this->_setCounter();
return true;
}
/**
* Create a new session and copy variables from the old one
*
* @return boolean $result true on success
*
* @since 11.1
*/
public function fork()
{
if ($this->_state !== 'active')
{
// @TODO :: generated error here
return false;
}
// Keep session config
$cookie = session_get_cookie_params();
// Kill session
session_destroy();
// Re-register the session store after a session has been destroyed, to avoid PHP bug
$this->_store->register();
// Restore config
session_set_cookie_params($cookie['lifetime'], $cookie['path'], $cookie['domain'], $cookie['secure'], true);
// Restart session with new id
session_regenerate_id(true);
session_start();
return true;
}
/**
* Writes session data and ends session
*
* Session data is usually stored after your script terminated without the need
* to call JSession::close(), but as session data is locked to prevent concurrent
* writes only one script may operate on a session at any time. When using
* framesets together with sessions you will experience the frames loading one
* by one due to this locking. You can reduce the time needed to load all the
* frames by ending the session as soon as all changes to session variables are
* done.
*
* @return void
*
* @see session_write_close()
* @since 11.1
*/
public function close()
{
session_write_close();
}
/**
* Set session cookie parameters
*
* @return void
*
* @since 11.1
*/
protected function _setCookieParams()
{
$cookie = session_get_cookie_params();
if ($this->_force_ssl)
{
$cookie['secure'] = true;
}
$config = JFactory::getConfig();
if ($config->get('cookie_domain', '') != '')
{
$cookie['domain'] = $config->get('cookie_domain');
}
if ($config->get('cookie_path', '') != '')
{
$cookie['path'] = $config->get('cookie_path');
}
session_set_cookie_params($cookie['lifetime'], $cookie['path'], $cookie['domain'], $cookie['secure'], true);
}
/**
* Create a token-string
*
* @param integer $length Length of string
*
* @return string Generated token
*
* @since 11.1
*/
protected function _createToken($length = 32)
{
static $chars = '0123456789abcdef';
$max = strlen($chars) - 1;
$token = '';
$name = session_name();
for ($i = 0; $i < $length; ++$i)
{
$token .= $chars[(rand(0, $max))];
}
return md5($token . $name);
}
/**
* Set counter of session usage
*
* @return boolean True on success
*
* @since 11.1
*/
protected function _setCounter()
{
$counter = $this->get('session.counter', 0);
++$counter;
$this->set('session.counter', $counter);
return true;
}
/**
* Set the session timers
*
* @return boolean True on success
*
* @since 11.1
*/
protected function _setTimers()
{
if (!$this->has('session.timer.start'))
{
$start = time();
$this->set('session.timer.start', $start);
$this->set('session.timer.last', $start);
$this->set('session.timer.now', $start);
}
$this->set('session.timer.last', $this->get('session.timer.now'));
$this->set('session.timer.now', time());
return true;
}
/**
* Set additional session options
*
* @param array $options List of parameter
*
* @return boolean True on success
*
* @since 11.1
*/
protected function _setOptions(array $options)
{
// Set name
if (isset($options['name']))
{
session_name(md5($options['name']));
}
// Set id
if (isset($options['id']))
{
session_id($options['id']);
}
// Set expire time
if (isset($options['expire']))
{
$this->_expire = $options['expire'];
}
// Get security options
if (isset($options['security']))
{
$this->_security = explode(',', $options['security']);
}
if (isset($options['force_ssl']))
{
$this->_force_ssl = (bool) $options['force_ssl'];
}
// Sync the session maxlifetime
ini_set('session.gc_maxlifetime', $this->_expire);
return true;
}
/**
* Do some checks for security reason
*
* - timeout check (expire)
* - ip-fixiation
* - browser-fixiation
*
* If one check failed, session data has to be cleaned.
*
* @param boolean $restart Reactivate session
*
* @return boolean True on success
*
* @see http://shiflett.org/articles/the-truth-about-sessions
* @since 11.1
*/
protected function _validate($restart = false)
{
// Allow to restart a session
if ($restart)
{
$this->_state = 'active';
$this->set('session.client.address', null);
$this->set('session.client.forwarded', null);
$this->set('session.client.browser', null);
$this->set('session.token', null);
}
// Check if session has expired
if ($this->_expire)
{
$curTime = $this->get('session.timer.now', 0);
$maxTime = $this->get('session.timer.last', 0) + $this->_expire;
// Empty session variables
if ($maxTime < $curTime)
{
$this->_state = 'expired';
return false;
}
}
// Record proxy forwarded for in the session in case we need it later
if (isset($_SERVER['HTTP_X_FORWARDED_FOR']))
{
$this->set('session.client.forwarded', $_SERVER['HTTP_X_FORWARDED_FOR']);
}
// Check for client address
if (in_array('fix_adress', $this->_security) && isset($_SERVER['REMOTE_ADDR']))
{
$ip = $this->get('session.client.address');
if ($ip === null)
{
$this->set('session.client.address', $_SERVER['REMOTE_ADDR']);
}
elseif ($_SERVER['REMOTE_ADDR'] !== $ip)
{
$this->_state = 'error';
return false;
}
}
// Check for clients browser
if (in_array('fix_browser', $this->_security) && isset($_SERVER['HTTP_USER_AGENT']))
{
$browser = $this->get('session.client.browser');
if ($browser === null)
{
$this->set('session.client.browser', $_SERVER['HTTP_USER_AGENT']);
}
elseif ($_SERVER['HTTP_USER_AGENT'] !== $browser)
{
// @todo remove code: $this->_state = 'error';
// @todo remove code: return false;
}
}
return true;
}
}

Documentation generated on Tue, 19 Nov 2013 15:12:52 +0100 by phpDocumentor 1.4.3

Source for file session.php