Subversion Repositories SmartDukaan

<?php
/**
 * Session class for CakePHP.
 *
 * CakePHP abstracts the handling of sessions.
 * There are several convenient methods to access session information.
 * This class is the implementation of those methods.
 * They are mostly used by the Session Component.
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.Model.Datasource
 * @since         CakePHP(tm) v .0.10.0.1222
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */

App::uses('Hash', 'Utility');
App::uses('Security', 'Utility');

/**
 * Session class for CakePHP.
 *
 * CakePHP abstracts the handling of sessions. There are several convenient methods to access session information.
 * This class is the implementation of those methods. They are mostly used by the Session Component.
 *
 * @package       Cake.Model.Datasource
 */
class CakeSession {

/**
 * True if the Session is still valid
 *
 * @var bool
 */
        public static $valid = false;

/**
 * Error messages for this session
 *
 * @var array
 */
        public static $error = false;

/**
 * User agent string
 *
 * @var string
 */
        protected static $_userAgent = '';

/**
 * Path to where the session is active.
 *
 * @var string
 */
        public static $path = '/';

/**
 * Error number of last occurred error
 *
 * @var int
 */
        public static $lastError = null;

/**
 * Start time for this session.
 *
 * @var int
 */
        public static $time = false;

/**
 * Cookie lifetime
 *
 * @var int
 */
        public static $cookieLifeTime;

/**
 * Time when this session becomes invalid.
 *
 * @var int
 */
        public static $sessionTime = false;

/**
 * Current Session id
 *
 * @var string
 */
        public static $id = null;

/**
 * Hostname
 *
 * @var string
 */
        public static $host = null;

/**
 * Session timeout multiplier factor
 *
 * @var int
 */
        public static $timeout = null;

/**
 * Number of requests that can occur during a session time without the session being renewed.
 * This feature is only used when config value `Session.autoRegenerate` is set to true.
 *
 * @var int
 * @see CakeSession::_checkValid()
 */
        public static $requestCountdown = 10;

/**
 * Whether or not the init function in this class was already called
 *
 * @var bool
 */
        protected static $_initialized = false;

/**
 * Session cookie name
 *
 * @var string
 */
        protected static $_cookieName = null;

/**
 * Pseudo constructor.
 *
 * @param string|null $base The base path for the Session
 * @return void
 */
        public static function init($base = null) {
                static::$time = time();

                if (env('HTTP_USER_AGENT')) {
                        static::$_userAgent = md5(env('HTTP_USER_AGENT') . Configure::read('Security.salt'));
                }

                static::_setPath($base);
                static::_setHost(env('HTTP_HOST'));

                if (!static::$_initialized) {
                        register_shutdown_function('session_write_close');
                }

                static::$_initialized = true;
        }

/**
 * Setup the Path variable
 *
 * @param string|null $base base path
 * @return void
 */
        protected static function _setPath($base = null) {
                if (empty($base)) {
                        static::$path = '/';
                        return;
                }
                if (strpos($base, 'index.php') !== false) {
                        $base = str_replace('index.php', '', $base);
                }
                if (strpos($base, '?') !== false) {
                        $base = str_replace('?', '', $base);
                }
                static::$path = $base;
        }

/**
 * Set the host name
 *
 * @param string $host Hostname
 * @return void
 */
        protected static function _setHost($host) {
                static::$host = $host;
                if (strpos(static::$host, ':') !== false) {
                        static::$host = substr(static::$host, 0, strpos(static::$host, ':'));
                }
        }

/**
 * Starts the Session.
 *
 * @return bool True if session was started
 */
        public static function start() {
                if (static::started()) {
                        return true;
                }

                $id = static::id();
                static::_startSession();

                if (!$id && static::started()) {
                        static::_checkValid();
                }

                static::$error = false;
                static::$valid = true;
                return static::started();
        }

/**
 * Determine if Session has been started.
 *
 * @return bool True if session has been started.
 */
        public static function started() {
                return isset($_SESSION) && session_id();
        }

/**
 * Returns true if given variable is set in session.
 *
 * @param string $name Variable name to check for
 * @return bool True if variable is there
 */
        public static function check($name) {
                if (empty($name) || !static::_hasSession() || !static::start()) {
                        return false;
                }

                return Hash::get($_SESSION, $name) !== null;
        }

/**
 * Returns the session id.
 * Calling this method will not auto start the session. You might have to manually
 * assert a started session.
 *
 * Passing an id into it, you can also replace the session id if the session
 * has not already been started.
 * Note that depending on the session handler, not all characters are allowed
 * within the session id. For example, the file session handler only allows
 * characters in the range a-z A-Z 0-9 , (comma) and - (minus).
 *
 * @param string|null $id Id to replace the current session id
 * @return string Session id
 */
        public static function id($id = null) {
                if ($id) {
                        static::$id = $id;
                        session_id(static::$id);
                }
                if (static::started()) {
                        return session_id();
                }
                return static::$id;
        }

/**
 * Removes a variable from session.
 *
 * @param string $name Session variable to remove
 * @return bool Success
 */
        public static function delete($name) {
                if (static::check($name)) {
                        static::_overwrite($_SESSION, Hash::remove($_SESSION, $name));
                        return !static::check($name);
                }
                return false;
        }

/**
 * Used to write new data to _SESSION, since PHP doesn't like us setting the _SESSION var itself.
 *
 * @param array &$old Set of old variables => values
 * @param array $new New set of variable => value
 * @return void
 */
        protected static function _overwrite(&$old, $new) {
                if (!empty($old)) {
                        foreach ($old as $key => $var) {
                                if (!isset($new[$key])) {
                                        unset($old[$key]);
                                }
                        }
                }
                foreach ($new as $key => $var) {
                        $old[$key] = $var;
                }
        }

/**
 * Return error description for given error number.
 *
 * @param int $errorNumber Error to set
 * @return string Error as string
 */
        protected static function _error($errorNumber) {
                if (!is_array(static::$error) || !array_key_exists($errorNumber, static::$error)) {
                        return false;
                }
                return static::$error[$errorNumber];
        }

/**
 * Returns last occurred error as a string, if any.
 *
 * @return mixed Error description as a string, or false.
 */
        public static function error() {
                if (static::$lastError) {
                        return static::_error(static::$lastError);
                }
                return false;
        }

/**
 * Returns true if session is valid.
 *
 * @return bool Success
 */
        public static function valid() {
                if (static::start() && static::read('Config')) {
                        if (static::_validAgentAndTime() && static::$error === false) {
                                static::$valid = true;
                        } else {
                                static::$valid = false;
                                static::_setError(1, 'Session Highjacking Attempted !!!');
                        }
                }
                return static::$valid;
        }

/**
 * Tests that the user agent is valid and that the session hasn't 'timed out'.
 * Since timeouts are implemented in CakeSession it checks the current static::$time
 * against the time the session is set to expire. The User agent is only checked
 * if Session.checkAgent == true.
 *
 * @return bool
 */
        protected static function _validAgentAndTime() {
                $config = static::read('Config');
                $validAgent = (
                        Configure::read('Session.checkAgent') === false ||
                        isset($config['userAgent']) && static::$_userAgent === $config['userAgent']
                );
                return ($validAgent && static::$time <= $config['time']);
        }

/**
 * Get / Set the user agent
 *
 * @param string|null $userAgent Set the user agent
 * @return string Current user agent
 */
        public static function userAgent($userAgent = null) {
                if ($userAgent) {
                        static::$_userAgent = $userAgent;
                }
                if (empty(static::$_userAgent)) {
                        CakeSession::init(static::$path);
                }
                return static::$_userAgent;
        }

/**
 * Returns given session variable, or all of them, if no parameters given.
 *
 * @param string|null $name The name of the session variable (or a path as sent to Set.extract)
 * @return mixed The value of the session variable, null if session not available,
 *   session not started, or provided name not found in the session, false on failure.
 */
        public static function read($name = null) {
                if (empty($name) && $name !== null) {
                        return null;
                }
                if (!static::_hasSession() || !static::start()) {
                        return null;
                }
                if ($name === null) {
                        return static::_returnSessionVars();
                }
                $result = Hash::get($_SESSION, $name);

                if (isset($result)) {
                        return $result;
                }
                return null;
        }

/**
 * Returns all session variables.
 *
 * @return mixed Full $_SESSION array, or false on error.
 */
        protected static function _returnSessionVars() {
                if (!empty($_SESSION)) {
                        return $_SESSION;
                }
                static::_setError(2, 'No Session vars set');
                return false;
        }

/**
 * Writes value to given session variable name.
 *
 * @param string|array $name Name of variable
 * @param string $value Value to write
 * @return bool True if the write was successful, false if the write failed
 */
        public static function write($name, $value = null) {
                if (empty($name) || !static::start()) {
                        return false;
                }

                $write = $name;
                if (!is_array($name)) {
                        $write = array($name => $value);
                }
                foreach ($write as $key => $val) {
                        static::_overwrite($_SESSION, Hash::insert($_SESSION, $key, $val));
                        if (Hash::get($_SESSION, $key) !== $val) {
                                return false;
                        }
                }
                return true;
        }

/**
 * Reads and deletes a variable from session.
 *
 * @param string $name The key to read and remove (or a path as sent to Hash.extract).
 * @return mixed The value of the session variable, null if session not available,
 *   session not started, or provided name not found in the session.
 */
        public static function consume($name) {
                if (empty($name)) {
                        return null;
                }
                $value = static::read($name);
                if ($value !== null) {
                        static::_overwrite($_SESSION, Hash::remove($_SESSION, $name));
                }
                return $value;
        }

/**
 * Helper method to destroy invalid sessions.
 *
 * @return void
 */
        public static function destroy() {
                if (!static::started()) {
                        static::_startSession();
                }

                if (static::started()) {
                        session_destroy();
                }

                $_SESSION = null;
                static::$id = null;
                static::$_cookieName = null;
        }

/**
 * Clears the session.
 *
 * Optionally also clears the session id and renews the session.
 *
 * @param bool $renew If the session should also be renewed. Defaults to true.
 * @return void
 */
        public static function clear($renew = true) {
                if (!$renew) {
                        $_SESSION = array();
                        return;
                }

                $_SESSION = null;
                static::$id = null;
                static::renew();
        }

/**
 * Helper method to initialize a session, based on CakePHP core settings.
 *
 * Sessions can be configured with a few shortcut names as well as have any number of ini settings declared.
 *
 * @return void
 * @throws CakeSessionException Throws exceptions when ini_set() fails.
 */
        protected static function _configureSession() {
                $sessionConfig = Configure::read('Session');

                if (isset($sessionConfig['defaults'])) {
                        $defaults = static::_defaultConfig($sessionConfig['defaults']);
                        if ($defaults) {
                                $sessionConfig = Hash::merge($defaults, $sessionConfig);
                        }
                }
                if (!isset($sessionConfig['ini']['session.cookie_secure']) && env('HTTPS')) {
                        $sessionConfig['ini']['session.cookie_secure'] = 1;
                }
                if (isset($sessionConfig['timeout']) && !isset($sessionConfig['cookieTimeout'])) {
                        $sessionConfig['cookieTimeout'] = $sessionConfig['timeout'];
                }
                if (!isset($sessionConfig['ini']['session.cookie_lifetime'])) {
                        $sessionConfig['ini']['session.cookie_lifetime'] = $sessionConfig['cookieTimeout'] * 60;
                }

                if (!isset($sessionConfig['ini']['session.name'])) {
                        $sessionConfig['ini']['session.name'] = $sessionConfig['cookie'];
                }
                static::$_cookieName = $sessionConfig['ini']['session.name'];

                if (!empty($sessionConfig['handler'])) {
                        $sessionConfig['ini']['session.save_handler'] = 'user';
                } elseif (!empty($sessionConfig['session.save_path']) && Configure::read('debug')) {
                        if (!is_dir($sessionConfig['session.save_path'])) {
                                mkdir($sessionConfig['session.save_path'], 0775, true);
                        }
                }

                if (!isset($sessionConfig['ini']['session.gc_maxlifetime'])) {
                        $sessionConfig['ini']['session.gc_maxlifetime'] = $sessionConfig['timeout'] * 60;
                }
                if (!isset($sessionConfig['ini']['session.cookie_httponly'])) {
                        $sessionConfig['ini']['session.cookie_httponly'] = 1;
                }

                if (empty($_SESSION)) {
                        if (!empty($sessionConfig['ini']) && is_array($sessionConfig['ini'])) {
                                foreach ($sessionConfig['ini'] as $setting => $value) {
                                        if (ini_set($setting, $value) === false) {
                                                throw new CakeSessionException(__d('cake_dev', 'Unable to configure the session, setting %s failed.', $setting));
                                        }
                                }
                        }
                }
                if (!empty($sessionConfig['handler']) && !isset($sessionConfig['handler']['engine'])) {
                        call_user_func_array('session_set_save_handler', $sessionConfig['handler']);
                }
                if (!empty($sessionConfig['handler']['engine'])) {
                        $handler = static::_getHandler($sessionConfig['handler']['engine']);
                        session_set_save_handler(
                                array($handler, 'open'),
                                array($handler, 'close'),
                                array($handler, 'read'),
                                array($handler, 'write'),
                                array($handler, 'destroy'),
                                array($handler, 'gc')
                        );
                }
                Configure::write('Session', $sessionConfig);
                static::$sessionTime = static::$time + ($sessionConfig['timeout'] * 60);
        }

/**
 * Get session cookie name.
 *
 * @return string
 */
        protected static function _cookieName() {
                if (static::$_cookieName !== null) {
                        return static::$_cookieName;
                }

                static::init();
                static::_configureSession();

                return static::$_cookieName = session_name();
        }

/**
 * Returns whether a session exists
 *
 * @return bool
 */
        protected static function _hasSession() {
                return static::started() || isset($_COOKIE[static::_cookieName()]);
        }

/**
 * Find the handler class and make sure it implements the correct interface.
 *
 * @param string $handler Handler name.
 * @return void
 * @throws CakeSessionException
 */
        protected static function _getHandler($handler) {
                list($plugin, $class) = pluginSplit($handler, true);
                App::uses($class, $plugin . 'Model/Datasource/Session');
                if (!class_exists($class)) {
                        throw new CakeSessionException(__d('cake_dev', 'Could not load %s to handle the session.', $class));
                }
                $handler = new $class();
                if ($handler instanceof CakeSessionHandlerInterface) {
                        return $handler;
                }
                throw new CakeSessionException(__d('cake_dev', 'Chosen SessionHandler does not implement CakeSessionHandlerInterface it cannot be used with an engine key.'));
        }

/**
 * Get one of the prebaked default session configurations.
 *
 * @param string $name Config name.
 * @return bool|array
 */
        protected static function _defaultConfig($name) {
                $defaults = array(
                        'php' => array(
                                'cookie' => 'CAKEPHP',
                                'timeout' => 240,
                                'ini' => array(
                                        'session.use_trans_sid' => 0,
                                        'session.cookie_path' => static::$path
                                )
                        ),
                        'cake' => array(
                                'cookie' => 'CAKEPHP',
                                'timeout' => 240,
                                'ini' => array(
                                        'session.use_trans_sid' => 0,
                                        'url_rewriter.tags' => '',
                                        'session.serialize_handler' => 'php',
                                        'session.use_cookies' => 1,
                                        'session.cookie_path' => static::$path,
                                        'session.save_path' => TMP . 'sessions',
                                        'session.save_handler' => 'files'
                                )
                        ),
                        'cache' => array(
                                'cookie' => 'CAKEPHP',
                                'timeout' => 240,
                                'ini' => array(
                                        'session.use_trans_sid' => 0,
                                        'url_rewriter.tags' => '',
                                        'session.use_cookies' => 1,
                                        'session.cookie_path' => static::$path,
                                        'session.save_handler' => 'user',
                                ),
                                'handler' => array(
                                        'engine' => 'CacheSession',
                                        'config' => 'default'
                                )
                        ),
                        'database' => array(
                                'cookie' => 'CAKEPHP',
                                'timeout' => 240,
                                'ini' => array(
                                        'session.use_trans_sid' => 0,
                                        'url_rewriter.tags' => '',
                                        'session.use_cookies' => 1,
                                        'session.cookie_path' => static::$path,
                                        'session.save_handler' => 'user',
                                        'session.serialize_handler' => 'php',
                                ),
                                'handler' => array(
                                        'engine' => 'DatabaseSession',
                                        'model' => 'Session'
                                )
                        )
                );
                if (isset($defaults[$name])) {
                        return $defaults[$name];
                }
                return false;
        }

/**
 * Helper method to start a session
 *
 * @return bool Success
 */
        protected static function _startSession() {
                static::init();
                session_write_close();
                static::_configureSession();

                if (headers_sent()) {
                        if (empty($_SESSION)) {
                                $_SESSION = array();
                        }
                } else {
                        // For IE<=8
                        session_cache_limiter("must-revalidate");
                        session_start();
                }
                return true;
        }

/**
 * Helper method to create a new session.
 *
 * @return void
 */
        protected static function _checkValid() {
                $config = static::read('Config');
                if ($config) {
                        $sessionConfig = Configure::read('Session');

                        if (static::valid()) {
                                static::write('Config.time', static::$sessionTime);
                                if (isset($sessionConfig['autoRegenerate']) && $sessionConfig['autoRegenerate'] === true) {
                                        $check = $config['countdown'];
                                        $check -= 1;
                                        static::write('Config.countdown', $check);

                                        if ($check < 1) {
                                                static::renew();
                                                static::write('Config.countdown', static::$requestCountdown);
                                        }
                                }
                        } else {
                                $_SESSION = array();
                                static::destroy();
                                static::_setError(1, 'Session Highjacking Attempted !!!');
                                static::_startSession();
                                static::_writeConfig();
                        }
                } else {
                        static::_writeConfig();
                }
        }

/**
 * Writes configuration variables to the session
 *
 * @return void
 */
        protected static function _writeConfig() {
                static::write('Config.userAgent', static::$_userAgent);
                static::write('Config.time', static::$sessionTime);
                static::write('Config.countdown', static::$requestCountdown);
        }

/**
 * Restarts this session.
 *
 * @return void
 */
        public static function renew() {
                if (session_id() === '') {
                        return;
                }
                if (isset($_COOKIE[session_name()])) {
                        setcookie(Configure::read('Session.cookie'), '', time() - 42000, static::$path);
                }
                session_regenerate_id(true);
        }

/**
 * Helper method to set an internal error message.
 *
 * @param int $errorNumber Number of the error
 * @param string $errorMessage Description of the error
 * @return void
 */
        protected static function _setError($errorNumber, $errorMessage) {
                if (static::$error === false) {
                        static::$error = array();
                }
                static::$error[$errorNumber] = $errorMessage;
                static::$lastError = $errorNumber;
        }

}