diff options
Diffstat (limited to 'system/libraries/Session/drivers/Session_cookie.php')
| -rwxr-xr-x | system/libraries/Session/drivers/Session_cookie.php | 583 |
1 files changed, 583 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..0982b1e01 --- /dev/null +++ b/system/libraries/Session/drivers/Session_cookie.php @@ -0,0 +1,583 @@ +<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); +/** + * CodeIgniter + * + * An open source application development framework for PHP 5.1.6 or newer + * + * @package CodeIgniter + * @author ExpressionEngine Dev Team + * @copyright Copyright (c) 2008 - 2010, EllisLab, Inc. + * @license http://codeigniter.com/user_guide/license.html + * @link http://codeigniter.com + * @since Version 2.0 + * @filesource + */ + + +/** + * Cookie-based session management driver + * + * This is the CI_Session functionality, as written by EllisLab, abstracted out to a driver. + * I have done a little updating for PHP5, and made minor changes to extract this functionality from + * the public interface (now in the Session Library), but effectively this code is unchanged. + * + * @package CodeIgniter + * @subpackage Libraries + * @category Sessions + * @author ExpressionEngine Dev Team and Darren Hill (DChill42) + */ +class Session_Cookie extends SessionDriver { + private $sess_encrypt_cookie = FALSE; + private $sess_use_database = FALSE; + private $sess_table_name = ''; + private $sess_expiration = 7200; + private $sess_expire_on_close = FALSE; + private $sess_match_ip = FALSE; + private $sess_match_useragent = TRUE; + private $sess_cookie_name = 'ci_session'; + private $cookie_prefix = ''; + private $cookie_path = ''; + private $cookie_domain = ''; + private $sess_time_to_update = 300; + private $encryption_key = ''; + private $time_reference = 'time'; + private $userdata = array(); + private $CI = null; + private $now = 0; + + const gc_probability = 5; + + /** + * 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 above or via the config file + foreach (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', 'sess_time_to_update', 'time_reference', 'cookie_prefix', 'encryption_key') 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) + { + $this->CI->load->library('encrypt'); + } + + // Are we using a database? If so, load it + if ($this->sess_use_database === TRUE && $this->sess_table_name != '') + { + $this->CI->load->database(); + } + + // 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 + $this->_sess_gc(); + } + + /** + * Write the session data + * + * @return void + */ + public function sess_save() + { + // Are we saving custom data to the DB? If not, all we do is update the cookie + if ($this->sess_use_database === FALSE) + { + $this->_set_cookie(); + return; + } + + // set the custom userdata, the session data we will set in a second + $custom_userdata = $this->all_userdata(); + $cookie_userdata = array(); + + // Before continuing, we need to determine if there is any custom data to deal with. + // Let's determine this by removing the default indexes to see if there's anything left in the array + // and set the session data while we're at it + foreach (array('session_id','ip_address','user_agent','last_activity') as $val) + { + unset($custom_userdata[$val]); + $cookie_userdata[$val] = $this->userdata($val); + } + + // Did we find any custom data? If not, we turn the empty array into a string + // since there's no reason to serialize and store an empty array in the DB + if (count($custom_userdata) === 0) + { + $custom_userdata = ''; + } + else + { + // Serialize the custom data array so we can store it + $custom_userdata = $this->_serialize($custom_userdata); + } + + // Run the update query + $this->CI->db->where('session_id', $this->userdata('session_id')); + $this->CI->db->update($this->sess_table_name, + array('last_activity' => $this->userdata('last_activity'), 'user_data' => $custom_userdata)); + + // Write the cookie. Notice that we manually pass the cookie data array to the + // _set_cookie() function. Normally that function will store $this->userdata, but + // in this case that array contains custom data, which we do not want in the cookie. + $this->_set_cookie($cookie_userdata); + } + + /** + * Destroy the current session + * + * @return void + */ + public function sess_destroy() + { + // Kill the session DB row + if ($this->sess_use_database === TRUE && $this->has_userdata('session_id')) + { + $this->CI->db->where('session_id', $this->userdata['session_id']); + $this->CI->db->delete($this->sess_table_name); + } + + // Kill the cookie + setcookie($this->sess_cookie_name, addslashes(serialize(array())), ($this->now - 31500000), + $this->cookie_path, $this->cookie_domain, 0); + } + + /** + * Regenerate the current session + * + * Regenerate the session id + * + * @param boolean Destroy session data flag (default: false) + * @return void + */ + public function sess_regenerate($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 private + * @return bool + */ + private function _sess_read() + { + // Fetch the cookie + $session = $this->CI->input->cookie($this->sess_cookie_name); + + // No cookie? Goodbye cruel world!... + if ($session === FALSE) + { + log_message('debug', 'A session cookie was not found.'); + return FALSE; + } + + // Decrypt the cookie data + if ($this->sess_encrypt_cookie == TRUE) + { + $session = $this->CI->encrypt->decode($session); + } + else + { + // encryption was not used, so we need to check the md5 hash + $hash = substr($session, strlen($session)-32); // get last 32 chars + $session = substr($session, 0, strlen($session)-32); + + // Does the md5 hash match? This is to prevent manipulation of session data in userspace + if ($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']) || ! isset($session['ip_address']) || + ! isset($session['user_agent']) || ! isset($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, 50))) + { + $this->sess_destroy(); + return FALSE; + } + + // Is there a corresponding session in the DB? + if ($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 = $this->CI->db->get($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 = $query->row(); + if (isset($row->user_data) && $row->user_data != '') + { + $custom_data = $this->_unserialize($row->user_data); + + if (is_array($custom_data)) + { + foreach ($custom_data as $key => $val) + { + $session[$key] = $val; + } + } + } + } + + // Session is valid! + $this->userdata = $session; + unset($session); + + return TRUE; + } + + /** + * Create a new session + * + * @access private + * @return void + */ + private function _sess_create() + { + $sessid = ''; + while (strlen($sessid) < 32) + { + $sessid .= mt_rand(0, mt_getrandmax()); + } + + // To make the session ID even more secure we'll combine it with the user's IP + $sessid .= $this->CI->input->ip_address(); + + $this->set_userdata('session_id', md5(uniqid($sessid, TRUE))); + $this->set_userdata('ip_address', $this->CI->input->ip_address()); + $this->set_userdata('user_agent', substr($this->CI->input->user_agent(), 0, 50)); + $this->set_userdata('last_activity',$this->now()); + + + // Save the data to the DB if needed + if ($this->sess_use_database === TRUE) + { + $this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $this->all_userdata())); + } + + // Write the cookie + $this->_set_cookie(); + } + + /** + * Update an existing session + * + * @access private + * @param boolean Force update flag (default: false) + * @return void + */ + private function _sess_update($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; + } + + // Save the old session id so we know which record to + // update in the database if we need it + $old_sessid = $this->userdata['session_id']; + $new_sessid = ''; + while (strlen($new_sessid) < 32) + { + $new_sessid .= mt_rand(0, mt_getrandmax()); + } + + // 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 + $new_sessid = md5(uniqid($new_sessid, TRUE)); + + // Update the session data in the session data array + $this->set_userdata('session_id', $new_sessid); + $this->set_userdata('last_activity', $this->now()); + + // _set_cookie() will handle this for us if we aren't using database sessions + // by pushing all userdata to the cookie. + $cookie_data = NULL; + + // Update the session ID and last_activity field in the DB if needed + if ($this->sess_use_database === TRUE) + { + // set cookie explicitly to only have our session data + $cookie_data = array(); + foreach (array('session_id','ip_address','user_agent','last_activity') as $val) + { + $cookie_data[$val] = $this->userdata[$val]; + } + + $this->CI->db->query($this->CI->db->update_string($this->sess_table_name, + array('last_activity' => $this->now(), 'session_id' => $new_sessid), + array('session_id' => $old_sessid))); + } + + // Write the cookie + $this->_set_cookie($cookie_data); + } + + /** + * Get the "now" time + * + * @access private + * @return int + */ + private function _get_time() + { + if (strtolower($this->time_reference) == 'gmt') + { + $now = time(); + $time = mktime(gmdate('H', $now), gmdate('i', $now), gmdate('s', $now), gmdate('m', $now), + gmdate('d', $now), gmdate('Y', $now)); + } + else + { + $time = time(); + } + + return $time; + } + + /** + * Write the session cookie + * + * @access private + * @param array Cookie name/value pairs + * @return void + */ + private function _set_cookie(array $cookie_data = NULL) + { + if (is_null($cookie_data)) + { + $cookie_data = $this->all_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 : $this->sess_expiration + time(); + + // Set the cookie + setcookie($this->sess_cookie_name, $cookie_data, $expire, $this->cookie_path, $this->cookie_domain, 0); + } + + /** + * Serialize an array + * + * This function first converts any slashes found in the array to a temporary + * marker, so when it gets unserialized the slashes will be preserved + * + * @access private + * @param mixed Data to serialize + * @return string + */ + private function _serialize($data) + { + if (is_array($data)) + { + foreach ($data as $key => $val) + { + if (is_string($val)) + { + $data[$key] = str_replace('\\', '{{slash}}', $val); + } + } + } + else + { + if (is_string($data)) + { + $data = str_replace('\\', '{{slash}}', $data); + } + } + + return serialize($data); + } + + /** + * Unserialize + * + * This function unserializes a data string, then converts any + * temporary slash markers back to actual slashes + * + * @access private + * @param string Data to unserialize + * @return mixed + */ + private function _unserialize($data) + { + $data = @unserialize(strip_slashes($data)); + + if (is_array($data)) + { + foreach ($data as $key => $val) + { + if (is_string($val)) + { + $data[$key] = str_replace('{{slash}}', '\\', $val); + } + } + + return $data; + } + + return (is_string($data)) ? str_replace('{{slash}}', '\\', $data) : $data; + } + + /** + * Garbage collection + * + * This deletes expired session rows from database + * if the probability percentage is met + * + * @access private + * @return void + */ + private function _sess_gc() + { + if ($this->sess_use_database != TRUE) + { + return; + } + + srand(time()); + if ((rand() % 100) < self::gc_probability) + { + $expire = $this->now() - $this->sess_expiration; + + $this->CI->db->where('last_activity < '.$expire); + $this->CI->db->delete($this->sess_table_name); + + log_message('debug', 'Session garbage collection performed.'); + } + } +} +// END Session_Cookie Class + +/* End of file Session_cookie.php */ +/* Location: ./system/libraries/Session/Session.php */ +?> |