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<?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
*/
/**
* Session Class
*
* @package CodeIgniter
* @subpackage Libraries
* @category Sessions
* @author EllisLab Dev Team
* @link http://codeigniter.com/user_guide/libraries/sessions.html
*/
class CI_Session {
public $sess_encrypt_cookie = FALSE;
public $sess_use_database = FALSE;
public $sess_table_name = '';
public $sess_expiration = 7200;
public $sess_expire_on_close = FALSE;
public $sess_match_ip = FALSE;
public $sess_match_useragent = TRUE;
public $sess_cookie_name = 'ci_session';
public $sess_use_multisessions = FALSE;
public $sess_multisession_expiration = 10;
public $cookie_prefix = '';
public $cookie_path = '';
public $cookie_domain = '';
public $cookie_secure = FALSE;
public $cookie_httponly = FALSE;
public $sess_time_to_update = 300;
public $encryption_key = '';
public $flashdata_key = 'flash';
public $time_reference = 'time';
public $gc_probability = 5;
public $userdata = array();
public $CI;
public $now;
private $prevent_update = FALSE;
private $multisession_expired = FALSE;
/**
* Session Constructor
*
* The constructor runs the session routines automatically
* whenever the class is instantiated.
*/
public function __construct($params = array())
{
log_message('debug', 'Session Class Initialized');
// 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', 'cookie_secure', 'cookie_httponly', 'sess_time_to_update', 'time_reference', 'cookie_prefix', 'encryption_key', 'sess_use_multisessions', 'sess_multisession_expiration') as $key)
{
$this->$key = (isset($params[$key])) ? $params[$key] : $this->CI->config->item($key);
}
if ($this->encryption_key == '')
{
show_error('In order to use the Session class 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 'old' flashdata (from last request)
$this->_flashdata_sweep();
// Mark all new flashdata as old (data will be deleted before next request)
$this->_flashdata_mark();
// Delete expired sessions if necessary
$this->_sess_gc();
log_message('debug', 'Session routines successfully run');
}
// --------------------------------------------------------------------
/**
* Fetch the current session data if it exists
*
* @return bool
*/
public 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($session) OR ! isset($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)
{
// Are we using multi-sessions? If so, grab a lock on the session
if ($this->sess_use_multisessions)
{
// Load the php session based on the current session id.
$this->_get_multi_session($session['session_id']);
}
$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)
{
$this->sess_destroy();
// Kill the multi-session we started
if ($this->sess_use_multisessions)
{
session_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] = $val;
}
}
}
// Are we in a multi-session scenario? If so, set whether the current
// session id is allowed to be updated.
if ($this->sess_use_multisessions)
{
$this->prevent_update = isset($row->prevent_update)?$row->prevent_update:NULL;
// Check to see if this session doesn't exist (previously destroyed)
// If so, kill it.
if (is_null($this->prevent_update))
{
$this->sess_destroy();
// Destroy the php session
session_destroy();
return FALSE;
}
}
}
// Session is valid!
$this->userdata = $session;
unset($session);
return TRUE;
}
// --------------------------------------------------------------------
/**
* Write the session data
*
* @return void
*/
public function sess_write()
{
//Is this an expired multisession? If so, prevent updates
if($this->multisession_expired())
{
return;
}
// Are we saving custom data to the DB? If not, all we do is update the cookie
if ($this->sess_use_database === FALSE)
{
$this->_set_cookie();
return;
}
// If we have enabled multi-session and have one that
// can no longer be updated, prevent the session write.
if($this->sess_use_multisessions && $this->prevent_update)
{
return;
}
// set the custom userdata, the session data we will set in a second
$custom_userdata = $this->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);
}
// --------------------------------------------------------------------
/**
* Create a new session
*
* @return void
*/
public 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' => $this->now,
'prevent_update' => 0,
'user_data' => ''
);
// Save the data to the DB if needed
if ($this->sess_use_database === TRUE)
{
$this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $this->userdata));
//Are we using multiple sessions?
if ($this->sess_use_multisessions)
{
/* Setup the php session to store information on whether
* or not the session can be updated
*/
$this->_get_multi_session($this->userdata['session_id']);
$this->prevent_update = FALSE;
$this->multisession_expired = FALSE;
unset($this->userdata['prevent_update']);
session_write_close();
}
}
// Write the cookie
$this->_set_cookie();
}
// --------------------------------------------------------------------
/**
* Update an existing session
*
* @return void
*/
public function sess_update()
{
// We only update the session every five minutes by default
if (($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
{
if ($this->sess_use_database && $this->sess_use_multisessions)
{
session_write_close();
}
return;
}
// Check if this session is no longer allowed to update and has exired.
// If so, flag it as expired so we can take action as appropriate.
if ($this->prevent_update && ($this->userdata['last_activity'] + $this->sess_multisession_expiration) < $this->now)
{
$this->multisession_expired = TRUE;
session_write_close();
return;
}
// We only allow sessions to update if they are allowed
if ($this->sess_use_database && $this->sess_use_multisessions && $this->prevent_update)
{
session_write_close();
return;
}
// _set_cookie() will handle this for us if we aren't using database sessions
// by pushing all userdata to the cookie.
$cookie_data = NULL;
// Changing the session ID during an AJAX call causes problems,
// so we'll only update our last_activity, but only if we are not
// using multiple sessions.
if ($this->CI->input->is_ajax_request() && !$this->sess_use_multisessions)
{
$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];
}
//Are we allowing multiple sessions?
if ($this->sess_use_multisessions)
{
//Set the session as no longer allowing updates
$this->prevent_update = TRUE;
//Update the current session
$this->CI->db->query($this->CI->db->update_string($this->sess_table_name, array('last_activity' => $this->now, 'prevent_update' => 1), array('session_id' => $old_sessid)));
//Release the session lock so other requests can process
session_write_close();
/* Create a new entry for the updated session id. This will be the only
* session id that can continue to update.
*/
$this->_get_multi_session($new_sessid);
$this->prevent_update = FALSE;
//Write the new session id to the database
$this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $cookie_data + array('prevent_update' => 0)));
//Make sure the user data is copied over
$this->sess_write();
//Release the session lock for the new session
session_write_close();
//Return immediately, as sess_write wrote the cookie
return;
}
else
{
$this->CI->db->query($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);
}
// --------------------------------------------------------------------
/**
* 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->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,
$this->cookie_domain,
0
);
}
// --------------------------------------------------------------------
/**
* Indicates if the session is an expired multi-session
*
* @return boolean
*/
public function multisession_expired()
{
return ($this->sess_use_multisessions && $this->multisession_expired);
}
// --------------------------------------------------------------------
/**
* Fetch a specific item from the session array
*
* @param string
* @return string
*/
public function userdata($item)
{
return isset($this->userdata[$item]) ? $this->userdata[$item] : FALSE;
}
// --------------------------------------------------------------------
/**
* Fetch all session data
*
* @return array
*/
public function all_userdata()
{
return $this->userdata;
}
// --------------------------------------------------------------------------
/**
* Fetch all flashdata
*
* @return array
*/
public function all_flashdata()
{
$out = array();
// loop through all userdata
foreach ($this->all_userdata() as $key => $val)
{
// if it contains flashdata, add it
if (strpos($key, 'flash:old:') !== FALSE)
{
$out[$key] = $val;
}
}
return $out;
}
// --------------------------------------------------------------------
/**
* Add or change data in the "userdata" array
*
* @param mixed
* @param string
* @return void
*/
public function set_userdata($newdata = array(), $newval = '')
{
//Is this an expired multisession? If so, prevent updates
if($this->multisession_expired())
{
return;
}
if (is_string($newdata))
{
$newdata = array($newdata => $newval);
}
if (count($newdata) > 0)
{
foreach ($newdata as $key => $val)
{
$this->userdata[$key] = $val;
}
}
$this->sess_write();
}
// --------------------------------------------------------------------
/**
* Delete a session variable from the "userdata" array
*
* @return void
*/
public function unset_userdata($newdata = array())
{
//Is this an expired multisession? If so, prevent updates
if($this->multisession_expired())
{
return;
}
if (is_string($newdata))
{
$newdata = array($newdata => '');
}
if (count($newdata) > 0)
{
foreach ($newdata as $key => $val)
{
unset($this->userdata[$key]);
}
}
$this->sess_write();
}
// ------------------------------------------------------------------------
/**
* Add or change flashdata, only available
* until the next request
*
* @param mixed
* @param string
* @return void
*/
public function set_flashdata($newdata = array(), $newval = '')
{
//Is this an expired multisession? If so, prevent updates
if($this->multisession_expired())
{
return;
}
if (is_string($newdata))
{
$newdata = array($newdata => $newval);
}
if (count($newdata) > 0)
{
foreach ($newdata as $key => $val)
{
$this->set_userdata($this->flashdata_key.':new:'.$key, $val);
}
}
}
// ------------------------------------------------------------------------
/**
* Keeps existing flashdata available to next request.
*
* @param string
* @return void
*/
public function keep_flashdata($key)
{
//Is this an expired multisession? If so, prevent updates
if($this->multisession_expired())
{
return;
}
// 'old' flashdata gets removed. Here we mark all
// flashdata as 'new' to preserve it from _flashdata_sweep()
// Note the function will return FALSE if the $key
// provided cannot be found
$value = $this->userdata($this->flashdata_key.':old:'.$key);
$this->set_userdata($this->flashdata_key.':new:'.$key, $value);
}
// ------------------------------------------------------------------------
/**
* Fetch a specific flashdata item from the session array
*
* @param string
* @return string
*/
public function flashdata($key)
{
return $this->userdata($this->flashdata_key.':old:'.$key);
}
// ------------------------------------------------------------------------
/**
* Identifies flashdata as 'old' for removal
* when _flashdata_sweep() runs.
*
* @return void
*/
protected function _flashdata_mark()
{
$userdata = $this->all_userdata();
foreach ($userdata as $name => $value)
{
$parts = explode(':new:', $name);
if (is_array($parts) && count($parts) === 2)
{
$this->set_userdata($this->flashdata_key.':old:'.$parts[1], $value);
$this->unset_userdata($name);
}
}
}
// ------------------------------------------------------------------------
/**
* Removes all flashdata marked as 'old'
*
* @return void
*/
protected function _flashdata_sweep()
{
$userdata = $this->all_userdata();
foreach ($userdata as $key => $value)
{
if (strpos($key, ':old:'))
{
$this->unset_userdata($key);
}
}
}
// --------------------------------------------------------------------
/**
* Get the "now" time
*
* @return string
*/
protected function _get_time()
{
return (strtolower($this->time_reference) === 'gmt')
? mktime(gmdate('H'), gmdate('i'), gmdate('s'), gmdate('m'), gmdate('d'), gmdate('Y'))
: time();
}
// --------------------------------------------------------------------
/**
* Write the session cookie
*
* @return void
*/
protected function _set_cookie($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
setcookie(
$this->sess_cookie_name,
$cookie_data,
$expire,
$this->cookie_path,
$this->cookie_domain,
$this->cookie_secure,
$this->cookie_httponly
);
}
// --------------------------------------------------------------------
/**
* Serialize an array
*
* This function first converts any slashes found in the array to a temporary
* marker, so when it gets unserialized the slashes will be preserved
*
* @param array
* @return string
*/
protected function _serialize($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
*
* @param string
* @param string
* @return void
*/
protected function _escape_slashes(&$val, $key)
{
if (is_string($val))
{
$val = str_replace('\\', '{{slash}}', $val);
}
}
// --------------------------------------------------------------------
/**
* Unserialize
*
* This function unserializes a data string, then converts any
* temporary slash markers back to actual slashes
*
* @param array
* @return string
*/
protected function _unserialize($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) : $data;
}
// --------------------------------------------------------------------
/**
* Unescape slashes
*
* This function converts any slash markers back into actual slashes
*
* @param string
* @param string
* @return void
*/
protected function _unescape_slashes(&$val, $key)
{
if (is_string($val))
{
$val= str_replace('{{slash}}', '\\', $val);
}
}
// --------------------------------------------------------------------
/**
* Garbage collection
*
* This deletes expired session rows from database
* if the probability percentage is met
*
* @return void
*/
protected function _sess_gc()
{
if ($this->sess_use_database != TRUE)
{
return;
}
srand(time());
if ((rand() % 100) < $this->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.');
}
}
/**
* Multi-Sessions Setup
*
* Sets up a php session to handle a flag which
* indicates if a session id can update itself
* or not.
*
* @param string
* @return void
*/
protected function _get_multi_session($session_id)
{
/* This is a bit of a hack, but we need to pass around info on
* if the current session can be updated or not. Starting a php
* session will effectively block all subsequent requests for the
* same session id so that we can prevent race conditions that might
* allow erroneous updates to the session id.
*/
//Don't allow cookies for the php session
ini_set('session.use_cookies', '0');
ini_set('session.use_only_cookies', '0');
//Start a session using our internally generated session id
session_id($session_id);
session_start();
}
}
/* End of file Session.php */
/* Location: ./system/libraries/Session.php */
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