diff options
Diffstat (limited to 'system/libraries/Session/drivers/Session_cookie.php')
| -rwxr-xr-x | system/libraries/Session/drivers/Session_cookie.php | 799 |
1 files changed, 799 insertions, 0 deletions
diff --git a/system/libraries/Session/drivers/Session_cookie.php b/system/libraries/Session/drivers/Session_cookie.php new file mode 100755 index 000000000..69e5fde14 --- /dev/null +++ b/system/libraries/Session/drivers/Session_cookie.php @@ -0,0 +1,799 @@ +<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); +/** + * CodeIgniter + * + * An open source application development framework for PHP 5.2.4 or newer + * + * NOTICE OF LICENSE + * + * Licensed under the Open Software License version 3.0 + * + * This source file is subject to the Open Software License (OSL 3.0) that is + * bundled with this package in the files license.txt / license.rst. It is + * also available through the world wide web at this URL: + * http://opensource.org/licenses/OSL-3.0 + * If you did not receive a copy of the license and are unable to obtain it + * through the world wide web, please send an email to + * licensing@ellislab.com so we can send you a copy immediately. + * + * @package CodeIgniter + * @author EllisLab Dev Team + * @copyright Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/) + * @license http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0) + * @link http://codeigniter.com + * @since Version 1.0 + * @filesource + */ + +/** + * Cookie-based session management driver + * + * This is the classic CI_Session functionality, as written by EllisLab, abstracted out to a driver. + * + * @package CodeIgniter + * @subpackage Libraries + * @category Sessions + * @author EllisLab Dev Team + * @link http://codeigniter.com/user_guide/libraries/sessions.html + */ +class CI_Session_cookie extends CI_Session_driver { + /** + * Whether to encrypt the session cookie + * + * @var bool + */ + public $sess_encrypt_cookie = FALSE; + + /** + * Whether to use to the database for session storage + * + * @var bool + */ + public $sess_use_database = FALSE; + + /** + * Name of the database table in which to store sessions + * + * @var string + */ + public $sess_table_name = ''; + + /** + * Length of time (in seconds) for sessions to expire + * + * @var int + */ + public $sess_expiration = 7200; + + /** + * Whether to kill session on close of browser window + * + * @var bool + */ + public $sess_expire_on_close = FALSE; + + /** + * Whether to match session on ip address + * + * @var bool + */ + public $sess_match_ip = FALSE; + + /** + * Whether to match session on user-agent + * + * @var bool + */ + public $sess_match_useragent = TRUE; + + /** + * Name of session cookie + * + * @var string + */ + public $sess_cookie_name = 'ci_session'; + + /** + * Session cookie prefix + * + * @var string + */ + public $cookie_prefix = ''; + + /** + * Session cookie path + * + * @var string + */ + public $cookie_path = ''; + + /** + * Session cookie domain + * + * @var string + */ + public $cookie_domain = ''; + + /** + * Whether to set the cookie only on HTTPS connections + * + * @var bool + */ + public $cookie_secure = FALSE; + + /** + * Whether cookie should be allowed only to be sent by the server + * + * @var bool + */ + public $cookie_httponly = FALSE; + + /** + * Interval at which to update session + * + * @var int + */ + public $sess_time_to_update = 300; + + /** + * Key with which to encrypt the session cookie + * + * @var string + */ + public $encryption_key = ''; + + /** + * Timezone to use for the current time + * + * @var string + */ + public $time_reference = 'local'; + + /** + * Session data + * + * @var array + */ + public $userdata = array(); + + /** + * Reference to CodeIgniter instance + * + * @var object + */ + public $CI; + + /** + * Current time + * + * @var int + */ + public $now; + + /** + * Default userdata keys + * + * @var array + */ + protected $defaults = array( + 'session_id' => NULL, + 'ip_address' => NULL, + 'user_agent' => NULL, + 'last_activity' => NULL + ); + + /** + * Data needs DB update flag + * + * @var bool + */ + protected $data_dirty = FALSE; + + /** + * Initialize session driver object + * + * @access protected + * @return void + */ + protected function initialize() + { + // Set the super object to a local variable for use throughout the class + $this->CI =& get_instance(); + + // Set all the session preferences, which can either be set + // manually via the $params array or via the config file + $prefs = array( + 'sess_encrypt_cookie', + 'sess_use_database', + 'sess_table_name', + 'sess_expiration', + 'sess_expire_on_close', + 'sess_match_ip', + 'sess_match_useragent', + 'sess_cookie_name', + 'cookie_path', + 'cookie_domain', + 'cookie_secure', + 'cookie_httponly', + 'sess_time_to_update', + 'time_reference', + 'cookie_prefix', + 'encryption_key' + ); + foreach ($prefs as $key) + { + $this->$key = isset($this->_parent->params[$key]) ? $this->_parent->params[$key] : + $this->CI->config->item($key); + } + + if ($this->encryption_key === '') + { + show_error('In order to use the Cookie Session driver you are required to set an encryption key '. + 'in your config file.'); + } + + // Load the string helper so we can use the strip_slashes() function + $this->CI->load->helper('string'); + + // Do we need encryption? If so, load the encryption class + if ($this->sess_encrypt_cookie === TRUE) + { + $this->CI->load->library('encrypt'); + } + + // Check for database + if ($this->sess_use_database === TRUE && $this->sess_table_name !== '') + { + // Load database driver + $this->CI->load->database(); + + // Register shutdown function + register_shutdown_function(array($this, '_update_db')); + } + + // Set the "now" time. Can either be GMT or server time, based on the config prefs. + // We use this to set the "last activity" time + $this->now = $this->_get_time(); + + // Set the session length. If the session expiration is + // set to zero we'll set the expiration two years from now. + if ($this->sess_expiration === 0) + { + $this->sess_expiration = (60*60*24*365*2); + } + + // Set the cookie name + $this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name; + + // Run the Session routine. If a session doesn't exist we'll + // create a new one. If it does, we'll update it. + if ( ! $this->_sess_read()) + { + $this->_sess_create(); + } + else + { + $this->_sess_update(); + } + + // Delete expired sessions if necessary + $this->_sess_gc(); + } + + /** + * Write the session data + * + * @return void + */ + public function sess_save() + { + // Check for database + if ($this->sess_use_database === TRUE) + { + // Mark custom data as dirty so we know to update the DB + $this->data_dirty = TRUE; + } + + // Write the cookie + $this->_set_cookie(); + } + + /** + * Destroy the current session + * + * @return void + */ + public function sess_destroy() + { + // Kill the session DB row + if ($this->sess_use_database === TRUE && isset($this->userdata['session_id'])) + { + $this->CI->db->delete($this->sess_table_name, array('session_id' => $this->userdata['session_id'])); + } + + // Kill the cookie + $this->_setcookie($this->sess_cookie_name, addslashes(serialize(array())), ($this->now - 31500000), + $this->cookie_path, $this->cookie_domain, 0); + + // Kill session data + $this->userdata = array(); + } + + /** + * Regenerate the current session + * + * Regenerate the session id + * + * @param boolean Destroy session data flag (default: false) + * @return void + */ + public function sess_regenerate($destroy = false) + { + // Check destroy flag + if ($destroy) + { + // Destroy old session and create new one + $this->sess_destroy(); + $this->_sess_create(); + } + else + { + // Just force an update to recreate the id + $this->_sess_update(true); + } + } + + /** + * Get a reference to user data array + * + * @return array - Reference to userdata + */ + public function &get_userdata() + { + // Return reference to array + return $this->userdata; + } + + /** + * Fetch the current session data if it exists + * + * @access protected + * @return bool + */ + protected function _sess_read() + { + // Fetch the cookie + $session = $this->CI->input->cookie($this->sess_cookie_name); + + // No cookie? Goodbye cruel world!... + if ($session === NULL) + { + log_message('debug', 'A session cookie was not found.'); + return FALSE; + } + + // Check for encryption + if ($this->sess_encrypt_cookie === TRUE) + { + // Decrypt the cookie data + $session = $this->CI->encrypt->decode($session); + } + else + { + // Encryption was not used, so we need to check the md5 hash in the last 32 chars + $len = strlen($session)-32; + $hash = substr($session, $len); + $session = substr($session, 0, $len); + + // Does the md5 hash match? This is to prevent manipulation of session data in userspace + if ($hash !== md5($session.$this->encryption_key)) + { + log_message('error', 'The session cookie data did not match what was expected. '. + 'This could be a possible hacking attempt.'); + $this->sess_destroy(); + return FALSE; + } + } + + // Unserialize the session array + $session = $this->_unserialize($session); + + // Is the session data we unserialized an array with the correct format? + if ( ! is_array($session) || ! isset($session['session_id'], $session['ip_address'], $session['user_agent'], + $session['last_activity'])) + { + $this->sess_destroy(); + return FALSE; + } + + // Is the session current? + if (($session['last_activity'] + $this->sess_expiration) < $this->now) + { + $this->sess_destroy(); + return FALSE; + } + + // Does the IP match? + if ($this->sess_match_ip === TRUE && $session['ip_address'] !== $this->CI->input->ip_address()) + { + $this->sess_destroy(); + return FALSE; + } + + // Does the User Agent Match? + if ($this->sess_match_useragent === TRUE && + trim($session['user_agent']) !== trim(substr($this->CI->input->user_agent(), 0, 120))) + { + $this->sess_destroy(); + return FALSE; + } + + // Is there a corresponding session in the DB? + if ($this->sess_use_database === TRUE) + { + $this->CI->db->where('session_id', $session['session_id']); + + if ($this->sess_match_ip === TRUE) + { + $this->CI->db->where('ip_address', $session['ip_address']); + } + + if ($this->sess_match_useragent === TRUE) + { + $this->CI->db->where('user_agent', $session['user_agent']); + } + + $query = $this->CI->db->limit(1)->get($this->sess_table_name); + + // No result? Kill it! + if ($query->num_rows() === 0) + { + $this->sess_destroy(); + return FALSE; + } + + // Is there custom data? If so, add it to the main session array + $row = $query->row(); + if ( ! empty($row->user_data)) + { + $custom_data = $this->_unserialize($row->user_data); + + if (is_array($custom_data)) + { + $session = $session + $custom_data; + } + } + } + + // Session is valid! + $this->userdata = $session; + return TRUE; + } + + /** + * Create a new session + * + * @access protected + * @return void + */ + protected function _sess_create() + { + // Initialize userdata + $this->userdata = array( + 'session_id' => $this->_make_sess_id(), + 'ip_address' => $this->CI->input->ip_address(), + 'user_agent' => substr($this->CI->input->user_agent(), 0, 120), + 'last_activity' => $this->now, + ); + + // Check for database + if ($this->sess_use_database === TRUE) + { + // Add empty user_data field and save the data to the DB + $this->CI->db->set('user_data', '')->insert($this->sess_table_name, $this->userdata); + } + + // Write the cookie + $this->_set_cookie(); + } + + /** + * Update an existing session + * + * @access protected + * @param boolean Force update flag (default: false) + * @return void + */ + protected function _sess_update($force = FALSE) + { + // We only update the session every five minutes by default (unless forced) + if ( ! $force && ($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now) + { + return; + } + + // Update last activity to now + $this->userdata['last_activity'] = $this->now; + + // Save the old session id so we know which DB record to update + $old_sessid = $this->userdata['session_id']; + + // Changing the session ID during an AJAX call causes problems + if ( ! $this->CI->input->is_ajax_request()) + { + // Get new id + $this->userdata['session_id'] = $this->_make_sess_id(); + } + + // Check for database + if ($this->sess_use_database === TRUE) + { + // Update the session ID and last_activity field in the DB + $this->CI->db->update($this->sess_table_name, array( + 'last_activity' => $this->now, + 'session_id' => $this->userdata['session_id'] + ), array('session_id' => $old_sessid)); + } + + // Write the cookie + $this->_set_cookie(); + } + + /** + * Update database with current data + * + * This gets called from the shutdown function and also + * registered with PHP to run at the end of the request + * so it's guaranteed to update even when a fatal error + * occurs. The first call makes the update and clears the + * dirty flag so it won't happen twice. + */ + public function _update_db() + { + // Check for database and dirty flag and unsaved + if ($this->sess_use_database === TRUE && $this->data_dirty === TRUE) + { + // Set up activity and data fields to be set + // If we don't find custom data, user_data will remain an empty string + $set = array( + 'last_activity' => $this->userdata['last_activity'], + 'user_data' => '' + ); + + // Get the custom userdata, leaving out the defaults + // (which get stored in the cookie) + $userdata = array_diff_key($this->userdata, $this->defaults); + + // Did we find any custom data? + if ( ! empty($userdata)) + { + // Serialize the custom data array so we can store it + $set['user_data'] = $this->_serialize($userdata); + } + + // Run the update query + // Any time we change the session id, it gets updated immediately, + // so our where clause below is always safe + $this->CI->db->update($this->sess_table_name, $set, array('session_id' => $this->userdata['session_id'])); + + // Clear dirty flag to prevent double updates + $this->data_dirty = FALSE; + + log_message('debug', 'CI_Session Data Saved To DB'); + } + } + + /** + * Generate a new session id + * + * @return string Hashed session id + */ + protected function _make_sess_id() + { + $new_sessid = ''; + do + { + $new_sessid .= mt_rand(0, mt_getrandmax()); + } + while (strlen($new_sessid) < 32); + + // To make the session ID even more secure we'll combine it with the user's IP + $new_sessid .= $this->CI->input->ip_address(); + + // Turn it into a hash and return + return md5(uniqid($new_sessid, TRUE)); + } + + /** + * Get the "now" time + * + * @access protected + * @return int Time + */ + protected function _get_time() + { + if ($this->time_reference === 'local' || $this->time_reference === date_default_timezone_get()) + { + return time(); + } + + $datetime = new DateTime('now', new DateTimeZone($this->time_reference)); + sscanf($datetime->format('j-n-Y G:i:s'), '%d-%d-%d %d:%d:%d', $day, $month, $year, $hour, $minute, $second); + + return mktime($hour, $minute, $second, $month, $day, $year); + } + + /** + * Write the session cookie + * + * @access protected + * @return void + */ + protected function _set_cookie() + { + // Get userdata (only defaults if database) + if ($this->sess_use_database === TRUE) + { + $cookie_data = array_intersect_key($this->userdata, $this->defaults); + } + else + { + $cookie_data = $this->userdata; + } + + // Serialize the userdata for the cookie + $cookie_data = $this->_serialize($cookie_data); + + if ($this->sess_encrypt_cookie === TRUE) + { + $cookie_data = $this->CI->encrypt->encode($cookie_data); + } + else + { + // if encryption is not used, we provide an md5 hash to prevent userside tampering + $cookie_data = $cookie_data.md5($cookie_data.$this->encryption_key); + } + + $expire = ($this->sess_expire_on_close === TRUE) ? 0 : $this->sess_expiration + time(); + + // Set the cookie + $this->_setcookie($this->sess_cookie_name, $cookie_data, $expire, $this->cookie_path, $this->cookie_domain, + $this->cookie_secure, $this->cookie_httponly); + } + + /** + * Set a cookie with the system + * + * This abstraction of the setcookie call allows overriding for unit testing + * + * @access protected + * @param string Cookie name + * @param string Cookie value + * @param int Expiration time + * @param string Cookie path + * @param string Cookie domain + * @param bool Secure connection flag + * @param bool HTTP protocol only flag + * @return void + */ + protected function _setcookie($name, $value = '', $expire = 0, $path = '', $domain = '', $secure = false, + $httponly = false) + { + // Set the cookie + setcookie($name, $value, $expire, $path, $domain, $secure, $httponly); + } + + /** + * Serialize an array + * + * This function first converts any slashes found in the array to a temporary + * marker, so when it gets unserialized the slashes will be preserved + * + * @access protected + * @param mixed Data to serialize + * @return string Serialized data + */ + protected function _serialize($data) + { + if (is_array($data)) + { + array_walk_recursive($data, array(&$this, '_escape_slashes')); + } + elseif (is_string($data)) + { + $data = str_replace('\\', '{{slash}}', $data); + } + return serialize($data); + } + + /** + * Escape slashes + * + * This function converts any slashes found into a temporary marker + * + * @access protected + * @param string Value + * @param string Key + * @return void + */ + protected function _escape_slashes(&$val, $key) + { + if (is_string($val)) + { + $val = str_replace('\\', '{{slash}}', $val); + } + } + + /** + * Unserialize + * + * This function unserializes a data string, then converts any + * temporary slash markers back to actual slashes + * + * @access protected + * @param mixed Data to unserialize + * @return mixed Unserialized data + */ + protected function _unserialize($data) + { + $data = @unserialize(strip_slashes(trim($data))); + + if (is_array($data)) + { + array_walk_recursive($data, array(&$this, '_unescape_slashes')); + return $data; + } + + return is_string($data) ? str_replace('{{slash}}', '\\', $data) : $data; + } + + /** + * Unescape slashes + * + * This function converts any slash markers back into actual slashes + * + * @access protected + * @param string Value + * @param string Key + * @return void + */ + protected function _unescape_slashes(&$val, $key) + { + if (is_string($val)) + { + $val= str_replace('{{slash}}', '\\', $val); + } + } + + /** + * Garbage collection + * + * This deletes expired session rows from database + * if the probability percentage is met + * + * @access protected + * @return void + */ + protected function _sess_gc() + { + if ($this->sess_use_database !== TRUE) + { + return; + } + + $probability = ini_get('session.gc_probability'); + $divisor = ini_get('session.gc_divisor'); + + srand(time()); + if ((mt_rand(0, $divisor) / $divisor) < $probability) + { + $expire = $this->now - $this->sess_expiration; + $this->CI->db->delete($this->sess_table_name, 'last_activity < '.$expire); + + log_message('debug', 'Session garbage collection performed.'); + } + } +} + +/* End of file Session_cookie.php */ +/* Location: ./system/libraries/Session/drivers/Session_cookie.php */ |