system/libraries/Session/drivers/Session_cookie.php - code-igniter-v3-giggi - Gitiles

 <?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 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		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;

 	/**
 	 * 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
 		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', 'cookie_secure', 'cookie_httponly', '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
 		$this->_setcookie($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;
 		}

 		// 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'], $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($custom_data))
 				{
 					foreach ($custom_data as $key => $val)
 					{
 						$session[$key] = $val;
 					}
 				}
 			}
 		}

 		// Session is valid!
 		$this->userdata = $session;
 		unset($session);

 		return TRUE;
 	}

 	/**
 	 * Create a new session
 	 *
 	 * @access	protected
 	 * @return	void
 	 */
 	protected function _sess_create()
 	{
 		$sessid = '';
 		do
 		{
 			$sessid .= mt_rand(0, mt_getrandmax());
 		}
 		while (strlen($sessid) < 32);

 		// To make the session ID even more secure we'll combine it with the user's IP
 		$sessid .= $this->CI->input->ip_address();

 		$this->userdata = array(
 			'session_id'	=> md5(uniqid($sessid, TRUE)),
 			'ip_address'	=> $this->CI->input->ip_address(),
 			'user_agent'	=> substr($this->CI->input->user_agent(), 0, 120),
 			'last_activity'	=> $this->now,
 			'user_data'	=> ''
 		);

 		// 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->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;
 		}

 		// _set_cookie() will handle this for us if we aren't using database sessions
 		// by pushing all userdata to the cookie.
 		$cookie_data = NULL;

 		// Changing the session ID during an AJAX call causes problems, so we'll only update our last_activity
 		if ($this->CI->input->is_ajax_request())
 		{
 			$this->userdata['last_activity'] = $this->now;

 			// 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->userdata['last_activity']),
 											array('session_id' => $this->userdata['session_id'])));
 			}

 			return $this->_set_cookie($cookie_data);
 		}

 		// 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 = '';
 		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 update the session data array
 		$this->userdata['session_id'] = $new_sessid = md5(uniqid($new_sessid, TRUE));
 		$this->userdata['last_activity'] = $this->now;

 		// 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	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
 	 * @param	array	Cookie name/value pairs
 	 * @return	void
 	 */
 	protected function _set_cookie(array $cookie_data = NULL)
 	{
 		if (is_null($cookie_data))
 		{
 			$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;

 			$this->CI->db->where('last_activity < '.$expire);
 			$this->CI->db->delete($this->sess_table_name);

 			log_message('debug', 'Session garbage collection performed.');
 		}
 	}
 }

 /* End of file Session_cookie.php */
 /* Location: ./system/libraries/Session/drivers/Session_cookie.php */
	<?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 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 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;

	/**
	* 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
	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', 'cookie_secure', 'cookie_httponly', '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 = (6060243652);
	}

	// 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
	$this->_setcookie($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;
	}

	// 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'], $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($custom_data))
	{
	foreach ($custom_data as $key => $val)
	{
	$session[$key] = $val;
	}
	}
	}
	}

	// Session is valid!
	$this->userdata = $session;
	unset($session);

	return TRUE;
	}

	/**
	* Create a new session
	*
	* @access protected
	* @return void
	*/
	protected function _sess_create()
	{
	$sessid = '';
	do
	{
	$sessid .= mt_rand(0, mt_getrandmax());
	}
	while (strlen($sessid) < 32);

	// To make the session ID even more secure we'll combine it with the user's IP
	$sessid .= $this->CI->input->ip_address();

	$this->userdata = array(
	'session_id' => md5(uniqid($sessid, TRUE)),
	'ip_address' => $this->CI->input->ip_address(),
	'user_agent' => substr($this->CI->input->user_agent(), 0, 120),
	'last_activity' => $this->now,
	'user_data' => ''
	);

	// 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->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;
	}

	// _set_cookie() will handle this for us if we aren't using database sessions
	// by pushing all userdata to the cookie.
	$cookie_data = NULL;

	// Changing the session ID during an AJAX call causes problems, so we'll only update our last_activity
	if ($this->CI->input->is_ajax_request())
	{
	$this->userdata['last_activity'] = $this->now;

	// 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->userdata['last_activity']),
	array('session_id' => $this->userdata['session_id'])));
	}

	return $this->_set_cookie($cookie_data);
	}

	// 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 = '';
	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 update the session data array
	$this->userdata['session_id'] = $new_sessid = md5(uniqid($new_sessid, TRUE));
	$this->userdata['last_activity'] = $this->now;

	// 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 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
	* @param array Cookie name/value pairs
	* @return void
	*/
	protected function _set_cookie(array $cookie_data = NULL)
	{
	if (is_null($cookie_data))
	{
	$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;

	$this->CI->db->where('last_activity < '.$expire);
	$this->CI->db->delete($this->sess_table_name);

	log_message('debug', 'Session garbage collection performed.');
	}
	}
	}

	/* End of file Session_cookie.php */
	/* Location: ./system/libraries/Session/drivers/Session_cookie.php */