Merge pull request #353 from dchill42/session

Switched Sessions to use Drivers
Adding native PHP sessions and keeping original-flavor CI cookie sessions

12 files changed, 2484 insertions, 1063 deletions

diff --git a/system/core/Loader.php b/system/core/Loader.php
index 0bc6e844a..0d05649ca 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -409,8 +409,8 @@ class CI_Loader {
 	 * 1. The name of the "view" file to be included.
 	 * 2. An associative array of data to be extracted for use in the view.
 	 * 3. TRUE/FALSE - whether to return the data or load it. In
-	 *    some cases it's advantageous to be able to return data so that
-	 *    a developer can process it in some way.
+	 *	some cases it's advantageous to be able to return data so that
+	 *	a developer can process it in some way.
 	 *
 	 * @param	string
 	 * @param	array
@@ -633,13 +633,7 @@ class CI_Loader {
 			{
 				$this->driver($driver);
 			}
-			return FALSE;
-		}
-
-		if ( ! class_exists('CI_Driver_Library'))
-		{
-			// we aren't instantiating an object here, that'll be done by the Library itself
-			require BASEPATH.'libraries/Driver.php';
+			return;
 		}
 
 		if ($library === '')
@@ -837,10 +831,10 @@ class CI_Loader {
 		 * We buffer the output for two reasons:
 		 * 1. Speed. You get a significant speed boost.
 		 * 2. So that the final rendered template can be post-processed by
-		 *    the output class. Why do we need post processing? For one thing,
-		 *    in order to show the elapsed page load time. Unless we can
-		 *    intercept the content right before it's sent to the browser and
-		 *    then stop the timer it won't be accurate.
+		 *	the output class. Why do we need post processing? For one thing,
+		 *	in order to show the elapsed page load time. Unless we can
+		 *	intercept the content right before it's sent to the browser and
+		 *	then stop the timer it won't be accurate.
 		 */
 		ob_start();
 
@@ -915,6 +909,13 @@ class CI_Loader {
 
 			// Get the filename from the path
 			$class = substr($class, $last_slash);
+
+			// Check for match and driver base class
+			if (strtolower(trim($subdir, '/')) == strtolower($class) && ! class_exists('CI_Driver_Library'))
+			{
+				// We aren't instantiating an object here, just making the base class available
+				require BASEPATH.'libraries/Driver.php';
+			}
 		}
 
 		// We'll test for both lowercase and capitalized versions of the file name
@@ -996,14 +997,19 @@ class CI_Loader {
 				$this->_ci_loaded_files[] = $filepath;
 				return $this->_ci_init_class($class, '', $params, $object_name);
 			}
-
 		} // END FOREACH
 
 		// One last attempt. Maybe the library is in a subdirectory, but it wasn't specified?
 		if ($subdir === '')
 		{
 			$path = strtolower($class).'/'.$class;
-			return $this->_ci_load_class($path, $params);
+			return $this->_ci_load_class($path, $params, $object_name);
+		}
+		else if (ucfirst($subdir) != $subdir)
+		{
+			// Lowercase subdir failed - retry capitalized
+			$path = ucfirst($subdir).$class;
+			return $this->_ci_load_class($path, $params, $object_name);
 		}
 
 		// If we got this far we were unable to find the requested class.
@@ -1193,6 +1199,15 @@ class CI_Loader {
 			}
 		}
 
+		// Autoload drivers
+		if (isset($autoload['drivers']))
+		{
+			foreach ($autoload['drivers'] as $item)
+			{
+				$this->driver($item);
+			}
+		}
+
 		// Autoload models
 		if (isset($autoload['model']))
 		{
@@ -1260,4 +1275,4 @@ class CI_Loader {
 }
 
 /* End of file Loader.php */
-/* Location: ./system/core/Loader.php */
\ No newline at end of file
+/* Location: ./system/core/Loader.php */
diff --git a/system/libraries/Driver.php b/system/libraries/Driver.php
index d67ee2549..1d084c8e4 100644
--- a/system/libraries/Driver.php
+++ b/system/libraries/Driver.php
@@ -54,13 +54,29 @@ class CI_Driver_Library {
 	protected $lib_name;
 
 	/**
+	 * Get magic method
+	 *
 	 * The first time a child is used it won't exist, so we instantiate it
 	 * subsequents calls will go straight to the proper child.
 	 *
-	 * @param	mixed	$child
-	 * @return	mixed
+	 * @param   string  Child class name
+	 * @return  object  Child class
 	 */
 	public function __get($child)
+    {
+		// Try to load the driver
+		return $this->load_driver($child);
+	}
+
+	/**
+	 * Load driver
+	 *
+	 * Separate load_driver call to support explicit driver load by library or user
+	 *
+	 * @param   string  Child class name
+	 * @return  object  Child class
+	 */
+	public function load_driver($child)
 	{
 		if ( ! isset($this->lib_name))
 		{
@@ -268,4 +284,4 @@ class CI_Driver {
 }
 
 /* End of file Driver.php */
-/* Location: ./system/libraries/Driver.php */
\ No newline at end of file
+/* Location: ./system/libraries/Driver.php */
diff --git a/system/libraries/Session.php b/system/libraries/Session.php
deleted file mode 100644
index af38dc366..000000000
--- a/system/libraries/Session.php
+++ /dev/null
@@ -1,955 +0,0 @@
-<?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 {
-
-	/**
-	 * 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			= '';
-
-	/**
-	 * String to indicate flash data cookies
-	 *
-	 * @var string
-	 */
-	public $flashdata_key			= 'flash';
-
-	/**
-	 * 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 $now;
-
-	/**
-	 * Session Constructor
-	 *
-	 * The constructor runs the session routines automatically
-	 * whenever the class is instantiated.
-	 *
-	 * @param	array
-	 * @return	void
-	 */
-	public function __construct($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') 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 ($session === NULL)
-		{
-			log_message('debug', 'A session cookie was not found.');
-			return FALSE;
-		}
-
-		// Decrypt the cookie data
-		if ($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($session) OR ! isset($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)
-		{
-			$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;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Write the session data
-	 *
-	 * @return	void
-	 */
-	public function sess_write()
-	{
-		// 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->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'	=> $this->now,
-					'user_data'	=> ''
-				);
-
-		// Save the data to the DB if needed
-		if ($this->sess_use_database === TRUE)
-		{
-			$this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $this->userdata));
-		}
-
-		// Write the cookie
-		$this->_set_cookie();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update an existing session
-	 *
-	 * @return	void
-	 */
-	public function sess_update()
-	{
-		// We only update the session every five minutes by default
-		if (($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
-		{
-			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);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * 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
-			);
-
-		// Kill session data
-		$this->userdata = array();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Fetch a specific item from the session array
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function userdata($item)
-	{
-		return isset($this->userdata[$item]) ? $this->userdata[$item] : NULL;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * 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(), $newval = '')
-	{
-		if (is_string($newdata))
-		{
-			$newdata = array($newdata => $newval);
-		}
-
-		if (count($newdata) > 0)
-		{
-			foreach ($newdata as $key => $val)
-			{
-				$this->userdata[$key] = $val;
-			}
-		}
-
-		$this->sess_write();
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Delete a session variable from the "userdata" array
-	 *
-	 * @param	array
-	 * @return	void
-	 */
-	public function unset_userdata($newdata = array())
-	{
-		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(), $newval = '')
-	{
-		if (is_string($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)
-	{
-		// 'old' flashdata gets removed. Here we mark all
-		// flashdata as 'new' to preserve it from _flashdata_sweep()
-		// Note the function will return NULL 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()
-	{
-		if ($this->time_reference === 'local' OR $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, $year);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Write the session cookie
-	 *
-	 * @param	mixed
-	 * @return	void
-	 */
-	protected function _set_cookie($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;
-		}
-
-		$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.php */
-/* Location: ./system/libraries/Session.php */
\ No newline at end of file
diff --git a/system/libraries/Session/Session.php b/system/libraries/Session/Session.php
new file mode 100755
index 000000000..1f24456a4
--- /dev/null
+++ b/system/libraries/Session/Session.php
@@ -0,0 +1,630 @@
+<?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
+ */
+
+
+/**
+ * CI_Session Class
+ *
+ * The user interface defined by EllisLabs, now with puggable drivers to manage different storage mechanisms.
+ * By default, the cookie session driver will load, but the 'sess_driver' config/param item (see above) can be
+ * used to specify the 'native' driver, or any other you might create.
+ * Once loaded, this driver setup is a drop-in replacement for the former CI_Session library, taking its place as the
+ * 'session' member of the global controller framework (e.g.: $CI->session or $this->session).
+ * In keeping with the CI_Driver methodology, multiple drivers may be loaded, although this might be a bit confusing.
+ * The CI_Session library class keeps track of the most recently loaded driver as "current" to call for driver methods.
+ * Ideally, one driver is loaded and all calls go directly through the main library interface. However, any methods
+ * called through the specific driver will switch the "current" driver to itself before invoking the library method
+ * (which will then call back into the driver for low-level operations). So, alternation between two drivers can be
+ * achieved by specifying which driver to use for each call (e.g.: $this->session->native->set_userdata('foo', 'bar');
+ * $this->session->cookie->userdata('foo'); $this->session->native->unset_userdata('foo');). Notice in the previous
+ * example that the _native_ userdata value 'foo' would be set to 'bar', which would NOT be returned by the call for
+ * the _cookie_ userdata 'foo', nor would the _cookie_ value be unset by the call to unset the _native_ 'foo' value.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		ExpressionEngine Dev Team
+ * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+class CI_Session extends CI_Driver_Library {
+	public $params = array();
+	protected $current = null;
+	protected $userdata = array();
+
+	const FLASHDATA_KEY = 'flash';
+	const FLASHDATA_NEW = ':new:';
+	const FLASHDATA_OLD = ':old:';
+	const FLASHDATA_EXP = ':exp:';
+	const EXPIRATION_KEY = '__expirations';
+	const TEMP_EXP_DEF = 300;
+
+	/**
+	 * CI_Session constructor
+	 *
+	 * The constructor loads the configured driver ('sess_driver' in config.php or as a parameter), running
+	 * routines in its constructor, and manages flashdata aging.
+	 *
+	 * @param	array	Configuration parameters
+	 */
+	public function __construct(array $params = array())
+	{
+		log_message('debug', 'CI_Session Class Initialized');
+
+		// Get valid drivers list
+		$CI =& get_instance();
+		$this->valid_drivers = array(
+			'Session_native',
+		   	'Session_cookie'
+		);
+		$key = 'sess_valid_drivers';
+		$drivers = (isset($params[$key])) ? $params[$key] : $CI->config->item($key);
+		if ($drivers)
+		{
+			if ( ! is_array($drivers)) $drivers = array($drivers);
+
+			// Add driver names to valid list
+			foreach ($drivers as $driver)
+			{
+				if ( ! in_array(strtolower($driver), array_map('strtolower', $this->valid_drivers)))
+				{
+					$this->valid_drivers[] = $driver;
+				}
+			}
+		}
+
+		// Get driver to load
+		$key = 'sess_driver';
+		$driver = (isset($params[$key])) ? $params[$key] : $CI->config->item($key);
+		if ( ! $driver) $driver = 'cookie';
+		if ( ! in_array('session_'.strtolower($driver), array_map('strtolower', $this->valid_drivers)))
+		{
+			$this->valid_drivers[] = 'Session_'.$driver;
+		}
+
+		// Save a copy of parameters in case drivers need access
+		$this->params = $params;
+
+		// Load driver and get array reference
+		$this->load_driver($driver);
+
+		// 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 tempdata
+		$this->_tempdata_sweep();
+
+		log_message('debug', 'CI_Session routines successfully run');
+	}
+
+	/**
+	 * Loads session storage driver
+	 *
+	 * @param	string	Driver classname
+	 * @return	object	Loaded driver object
+	 */
+	public function load_driver($driver)
+	{
+		// Save reference to most recently loaded driver as library default and sync userdata
+		$this->current = parent::load_driver($driver);
+		$this->userdata =& $this->current->get_userdata();
+		return $this->current;
+	}
+
+	/**
+	 * Select default session storage driver
+	 *
+	 * @param	string	Driver classname
+	 * @return	void
+	 */
+	public function select_driver($driver)
+	{
+		// Validate driver name
+		$lowername = strtolower(str_replace('CI_', '', $driver));
+		if (in_array($lowername, array_map('strtolower', $this->valid_drivers)))
+		{
+			// See if driver is loaded
+			$child = str_replace($this->lib_name.'_', '', $driver);
+			if (isset($this->$child))
+			{
+				// See if driver is already current
+				if ($this->$child !== $this->current) {
+					// Make driver current and sync userdata
+					$this->current = $this->$child;
+					$this->userdata =& $this->current->get_userdata();
+				}
+			}
+			else
+			{
+				// Load new driver
+				$this->load_driver($child);
+			}
+		}
+	}
+
+	/**
+	 * Destroy the current session
+	 *
+	 * @return	void
+	 */
+	public function sess_destroy()
+	{
+		// Just call destroy on driver
+		$this->current->sess_destroy();
+	}
+
+	/**
+	 * Regenerate the current session
+	 *
+	 * @param	boolean	Destroy session data flag (default: false)
+	 * @return	void
+	 */
+	public function sess_regenerate($destroy = false)
+	{
+		// Call regenerate on driver and resync userdata
+		$this->current->sess_regenerate($destroy);
+		$this->userdata =& $this->current->get_userdata();
+	}
+
+	/**
+	 * Fetch a specific item from the session array
+	 *
+	 * @param	string	Item key
+	 * @return	string	Item value or NULL if not found
+	 */
+	public function userdata($item)
+	{
+		// Return value or NULL if not found
+		return ( ! isset($this->userdata[$item])) ? NULL : $this->userdata[$item];
+	}
+
+	/**
+	 * Fetch all session data
+	 *
+	 * @return	array	User data array
+	 */
+	public function all_userdata()
+	{
+		// Return entire array
+		return ( ! isset($this->userdata)) ? NULL : $this->userdata;
+	}
+
+	/**
+	 * Fetch all flashdata
+	 *
+	 * @return	array   Flash data 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, self::FLASHDATA_KEY.self::FLASHDATA_OLD) !== FALSE)
+			{
+				$key = str_replace(self::FLASHDATA_KEY.self::FLASHDATA_OLD, '', $key);
+				$out[$key] = $val;
+			}
+		}
+		return $out;
+	}
+
+	/**
+	 * Add or change data in the "userdata" array
+	 *
+	 * @param	mixed	Item name or array of items
+	 * @param	string	Item value or empty string
+	 * @return	void
+	 */
+	public function set_userdata($newdata = array(), $newval = '')
+	{
+		// Wrap params as array if singular
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => $newval);
+		}
+
+		// Set each name/value pair
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$this->userdata[$key] = $val;
+			}
+		}
+
+		// Tell driver data changed
+		$this->current->sess_save();
+	}
+
+	/**
+	 * Delete a session variable from the "userdata" array
+	 *
+	 * @param	mixed	Item name or array of item names
+	 * @return	void
+	 */
+	public function unset_userdata($newdata = array())
+	{
+		// Wrap single name as array
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => '');
+		}
+
+		// Unset each item name
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				unset($this->userdata[$key]);
+			}
+		}
+
+		// Tell driver data changed
+		$this->current->sess_save();
+	}
+
+	/**
+	 * Determine if an item exists
+	 *
+	 * @param	string	Item name
+	 * @return	boolean
+	 */
+	public function has_userdata($item)
+	{
+		// Check for item name
+		return isset($this->userdata[$item]);
+	}
+
+	/**
+	 * Add or change flashdata, only available until the next request
+	 *
+	 * @param	mixed	Item name or array of items
+	 * @param	string	Item value or empty string
+	 * @return	void
+	 */
+	public function set_flashdata($newdata = array(), $newval = '')
+	{
+		// Wrap item as array if singular
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => $newval);
+		}
+
+		// Prepend each key name and set value
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_NEW.$key;
+				$this->set_userdata($flashdata_key, $val);
+			}
+		}
+	}
+
+	/**
+	 * Keeps existing flashdata available to next request.
+	 *
+	 * @param	string	Item key
+	 * @return	void
+	 */
+	public function keep_flashdata($key)
+	{
+		// 'old' flashdata gets removed. Here we mark all flashdata as 'new' to preserve it from _flashdata_sweep()
+		// Note the function will return NULL if the $key provided cannot be found
+		$old_flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_OLD.$key;
+		$value = $this->userdata($old_flashdata_key);
+
+		$new_flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_NEW.$key;
+		$this->set_userdata($new_flashdata_key, $value);
+	}
+
+	/**
+	 * Fetch a specific flashdata item from the session array
+	 *
+	 * @param	string	Item key
+	 * @return	string
+	 */
+	public function flashdata($key)
+	{
+		// Prepend key and retrieve value
+		$flashdata_key = self::FLASHDATA_KEY.self::FLASHDATA_OLD.$key;
+		return $this->userdata($flashdata_key);
+	}
+
+	/**
+	 * Add or change tempdata, only available
+	 * until expiration
+	 *
+	 * @param	mixed	Item name or array of items
+	 * @param	string	Item value or empty string
+	 * @param	int		Item lifetime in seconds or 0 for default
+	 * @return	void
+	 */
+	public function set_tempdata($newdata = array(), $newval = '', $expire = 0)
+	{
+		// Set expiration time
+		$expire = time() + ($expire ? $expire : self::TEMP_EXP_DEF);
+
+		// Wrap item as array if singular
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => $newval);
+		}
+
+		// Get or create expiration list
+		$expirations = $this->userdata(self::EXPIRATION_KEY);
+		if ( ! $expirations)
+		{
+			$expirations = array();
+		}
+
+		// Prepend each key name and set value
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$tempdata_key = self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key;
+				$expirations[$tempdata_key] = $expire;
+				$this->set_userdata($tempdata_key, $val);
+			}
+		}
+
+		// Update expiration list
+		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+	}
+
+	/**
+	 * Delete a temporary session variable from the "userdata" array
+	 *
+	 * @param	mixed	Item name or array of item names
+	 * @return	void
+	 */
+	public function unset_tempdata($newdata = array())
+	{
+		// Get expirations list
+		$expirations = $this->userdata(self::EXPIRATION_KEY);
+		if ( ! $expirations || ! count($expirations))
+		{
+			// Nothing to do
+			return;
+		}
+
+		// Wrap single name as array
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => '');
+		}
+
+		// Prepend each item name and unset
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$tempdata_key = self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key;
+				unset($expirations[$tempdata_key]);
+				$this->unset_userdata($tempdata_key);
+			}
+		}
+
+		// Update expiration list
+		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+	}
+
+	/**
+	 * Fetch a specific tempdata item from the session array
+	 *
+	 * @param	string	Item key
+	 * @return	string
+	 */
+	public function tempdata($key)
+	{
+		// Prepend key and return value
+		$tempdata_key = self::FLASHDATA_KEY.self::FLASHDATA_EXP.$key;
+		return $this->userdata($tempdata_key);
+	}
+
+	/**
+	 * Identifies flashdata as 'old' for removal
+	 * when _flashdata_sweep() runs.
+	 *
+	 * @access	protected
+	 * @return	void
+	 */
+	protected function _flashdata_mark()
+	{
+		$userdata = $this->all_userdata();
+		foreach ($userdata as $name => $value)
+		{
+			$parts = explode(self::FLASHDATA_NEW, $name);
+			if (is_array($parts) && count($parts) === 2)
+			{
+				$new_name = self::FLASHDATA_KEY.self::FLASHDATA_OLD.$parts[1];
+				$this->set_userdata($new_name, $value);
+				$this->unset_userdata($name);
+			}
+		}
+	}
+
+	/**
+	 * Removes all flashdata marked as 'old'
+	 *
+	 * @access	protected
+	 * @return	void
+	 */
+	protected function _flashdata_sweep()
+	{
+		$userdata = $this->all_userdata();
+		foreach ($userdata as $key => $value)
+		{
+			if (strpos($key, self::FLASHDATA_OLD))
+			{
+				$this->unset_userdata($key);
+			}
+		}
+	}
+
+	/**
+	 * Removes all expired tempdata
+	 *
+	 * @access	protected
+	 * @return	void
+	 */
+	protected function _tempdata_sweep()
+	{
+		// Get expirations list
+		$expirations = $this->userdata(self::EXPIRATION_KEY);
+		if ( ! $expirations ||  ! count($expirations))
+		{
+			// Nothing to do
+			return;
+		}
+
+		// Unset expired elements
+		$now = time();
+		$userdata = $this->all_userdata();
+		foreach ($userdata as $key => $value)
+		{
+			if (strpos($key, self::FLASHDATA_EXP) && $expirations[$key] < $now)
+			{
+				unset($expirations[$key]);
+				$this->unset_userdata($key);
+			}
+		}
+
+		// Update expiration list
+		$this->set_userdata(self::EXPIRATION_KEY, $expirations);
+	}
+}
+// END CI_Session Class
+
+
+/**
+ * CI_Session_driver Class
+ *
+ * Extend this class to make a new CI_Session driver.
+ * A CI_Session driver basically manages an array of name/value pairs with some sort of storage mechanism.
+ * To make a new driver, derive from (extend) CI_Session_driver. Overload the initialize method and read or create
+ * session data. Then implement a save handler to write changed data to storage (sess_save), a destroy handler
+ * to remove deleted data (sess_destroy), and an access handler to expose the data (get_userdata).
+ * Put your driver in the libraries/Session/drivers folder anywhere in the loader paths. This includes the
+ * application directory, the system directory, or any path you add with $CI->load->add_package_path().
+ * Your driver must be named CI_Session_<name>, and your filename must be Session_<name>.php,
+ * preferably also capitalized. (e.g.: CI_Session_foo in libraries/Session/drivers/Session_foo.php)
+ * Then specify the driver by setting 'sess_driver' in your config file or as a parameter when loading the CI_Session
+ * object. (e.g.: $config['sess_driver'] = 'foo'; OR $CI->load->driver('session', array('sess_driver' => 'foo')); )
+ * Already provided are the Native driver, which manages the native PHP $_SESSION array, and
+ * the Cookie driver, which manages the data in a browser cookie, with optional extra storage in a database table.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		ExpressionEngine Dev Team
+ */
+abstract class CI_Session_driver extends CI_Driver {
+	/**
+	 * Decorate
+	 *
+	 * Decorates the child with the parent driver lib's methods and properties
+	 *
+	 * @param	object	Parent library object
+	 * @return	void
+	 */
+	public function decorate($parent)
+	{
+		// Call base class decorate first
+		parent::decorate($parent);
+
+		// Call initialize method now that driver has access to $this->_parent
+		$this->initialize();
+	}
+
+	/**
+	 * __call magic method
+	 *
+	 * Handles access to the parent driver library's methods
+	 *
+	 * @param	string	Library method name
+	 * @param	array	Method arguments (default: none)
+	 * @return	mixed
+	 */
+	public function __call($method, $args = array())
+	{
+		// Make sure the parent library uses this driver
+		$this->_parent->select_driver(get_class($this));
+		return parent::__call($method, $args);
+	}
+
+	/**
+	 * Initialize driver
+	 *
+	 * @return	void
+	 */
+	protected function initialize()
+	{
+		// Overload this method to implement initialization
+	}
+
+	/**
+	 * Save the session data
+	 *
+	 * Data in the array has changed - perform any storage synchronization necessary
+	 * The child class MUST implement this abstract method!
+	 *
+	 * @return	void
+	 */
+	abstract public function sess_save();
+
+	/**
+	 * Destroy the current session
+	 *
+	 * Clean up storage for this session - it has been terminated
+	 * The child class MUST implement this abstract method!
+	 *
+	 * @return	void
+	 */
+	abstract public function sess_destroy();
+
+	/**
+	 * Regenerate the current session
+	 *
+	 * Regenerate the session id
+	 * The child class MUST implement this abstract method!
+	 *
+	 * @param	boolean	Destroy session data flag (default: false)
+	 * @return	void
+	 */
+	abstract public function sess_regenerate($destroy = false);
+
+	/**
+	 * Get a reference to user data array
+	 *
+	 * Give array access to the main CI_Session object
+	 * The child class MUST implement this abstract method!
+	 *
+	 * @return	array	Reference to userdata
+	 */
+	abstract public function &get_userdata();
+}
+// END CI_Session_driver Class
+
+
+/* End of file Session.php */
+/* Location: ./system/libraries/Session/Session.php */
+?>
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 */
diff --git a/system/libraries/Session/drivers/Session_native.php b/system/libraries/Session/drivers/Session_native.php
new file mode 100755
index 000000000..8ba8e749a
--- /dev/null
+++ b/system/libraries/Session/drivers/Session_native.php
@@ -0,0 +1,211 @@
+<?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
+ */
+
+
+/**
+ * Native PHP session management driver
+ *
+ * This is the driver that uses the native PHP $_SESSION array through the Session driver library.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		ExpressionEngine Dev Team
+ */
+class CI_Session_native extends CI_Session_driver {
+	/**
+	 * Initialize session driver object
+	 *
+	 * @access	protected
+	 * @return	void
+	 */
+	protected function initialize()
+	{
+		// Get config parameters
+		$config = array();
+		$CI =& get_instance();
+		$prefs = array(
+			'sess_cookie_name',
+			'sess_expire_on_close',
+			'sess_expiration',
+			'sess_match_ip',
+			'sess_match_useragent',
+			'sess_time_to_update',
+			'cookie_prefix',
+			'cookie_path',
+			'cookie_domain'
+		);
+		foreach ($prefs as $key)
+		{
+			$config[$key] = isset($this->_parent->params[$key]) ? $this->_parent->params[$key] :
+				$CI->config->item($key);
+		}
+
+		// Set session name, if specified
+		if ($config['sess_cookie_name'])
+		{
+			// Differentiate name from cookie driver with '_id' suffix
+			$name = $config['sess_cookie_name'].'_id';
+			if ($config['cookie_prefix'])
+			{
+				// Prepend cookie prefix
+				$name = $config['cookie_prefix'].$name;
+			}
+			session_name($name);
+		}
+
+		// Set expiration, path, and domain
+		$expire = 7200;
+		$path = '/';
+		$domain = '';
+		if ($config['sess_expiration'] !== FALSE)
+		{
+			// Default to 2 years if expiration is "0"
+			$expire = ($config['sess_expiration'] == 0) ? (60*60*24*365*2) : $config['sess_expiration'];
+		}
+		if ($config['cookie_path'])
+		{
+			// Use specified path
+			$path = $config['cookie_path'];
+		}
+		if ($config['cookie_domain'])
+		{
+			// Use specified domain
+			$domain = $config['cookie_domain'];
+		}
+		session_set_cookie_params($config['sess_expire_on_close'] ? 0 : $expire, $path, $domain);
+
+		// Start session
+		session_start();
+
+		// Check session expiration, ip, and agent
+		$now = time();
+		$destroy = FALSE;
+		if (isset($_SESSION['last_activity']) && ($_SESSION['last_activity'] + $expire) < $now)
+		{
+			// Expired - destroy
+			$destroy = TRUE;
+		}
+		else if ($config['sess_match_ip'] == TRUE && isset($_SESSION['ip_address']) &&
+		$_SESSION['ip_address'] != $CI->input->ip_address())
+		{
+			// IP doesn't match - destroy
+			$destroy = TRUE;
+		}
+		else if ($config['sess_match_useragent'] == TRUE && isset($_SESSION['user_agent']) &&
+		$_SESSION['user_agent'] != trim(substr($CI->input->user_agent(), 0, 50)))
+		{
+			// Agent doesn't match - destroy
+			$destroy = TRUE;
+		}
+
+		// Destroy expired or invalid session
+		if ($destroy)
+		{
+			// Clear old session and start new
+			$this->sess_destroy();
+			session_start();
+		}
+
+		// Check for update time
+		if ($config['sess_time_to_update'] && isset($_SESSION['last_activity']) &&
+		($_SESSION['last_activity'] + $config['sess_time_to_update']) < $now)
+		{
+			// Regenerate ID, but don't destroy session
+			$this->sess_regenerate(FALSE);
+		}
+
+		// Set activity time
+		$_SESSION['last_activity'] = $now;
+
+		// Set matching values as required
+		if ($config['sess_match_ip'] == TRUE && !isset($_SESSION['ip_address']))
+		{
+			// Store user IP address
+			$_SESSION['ip_address'] = $CI->input->ip_address();
+		}
+		if ($config['sess_match_useragent'] == TRUE && !isset($_SESSION['user_agent']))
+		{
+			// Store user agent string
+			$_SESSION['user_agent'] = trim(substr($CI->input->user_agent(), 0, 50));
+		}
+
+		// Make session ID available
+		$_SESSION['session_id'] = session_id();
+	}
+
+	/**
+	 * Save the session data
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	public function sess_save()
+	{
+		// Nothing to do - changes to $_SESSION are automatically saved
+	}
+
+	/**
+	 * Destroy the current session
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	public function sess_destroy()
+	{
+		// Cleanup session
+		$_SESSION = array();
+		$name = session_name();
+		if (isset($_COOKIE[$name]))
+		{
+			// Clear session cookie
+			$params = session_get_cookie_params();
+			setcookie($name, '', time() - 42000, $params['path'], $params['domain']);
+			unset($_COOKIE[$name]);
+		}
+		session_destroy();
+	}
+
+	/**
+	 * Regenerate the current session
+	 *
+	 * Regenerate the session id
+	 *
+	 * @access	public
+	 * @param	boolean	Destroy session data flag (default: FALSE)
+	 * @return	void
+	 */
+	public function sess_regenerate($destroy = FALSE)
+	{
+		// Just regenerate id, passing destroy flag
+		session_regenerate_id($destroy);
+		$_SESSION['session_id'] = session_id();
+	}
+
+	/**
+	 * Get a reference to user data array
+	 *
+	 * @access	public
+	 * @return	array	Reference to userdata
+	 */
+	public function &get_userdata()
+	{
+		// Just return reference to $_SESSION
+		return $_SESSION;
+	}
+}
+
+/* End of file Session_native.php */
+/* Location: ./system/libraries/Session/drivers/Session_native.php */
diff --git a/tests/codeigniter/libraries/Session_test.php b/tests/codeigniter/libraries/Session_test.php
new file mode 100644
index 000000000..135f71806
--- /dev/null
+++ b/tests/codeigniter/libraries/Session_test.php
@@ -0,0 +1,405 @@
+<?php
+
+/**
+ * Session driver library unit test
+ */
+class Session_test extends CI_TestCase {
+	protected $settings = array(
+		'use_cookies' => 0,
+	   	'use_only_cookies' => 0,
+	   	'cache_limiter' => false
+	);
+	protected $setting_vals = array();
+	protected $cookie_vals;
+	protected $session;
+
+	/**
+	 * Set up test framework
+	 */
+	public function set_up()
+	{
+		// Override settings
+		foreach ($this->settings as $name => $value) {
+			$this->setting_vals[$name] = ini_get('session.'.$name);
+			ini_set('session.'.$name, $value);
+		}
+
+		// Start with clean environment
+		$this->cookie_vals = $_COOKIE;
+		$_COOKIE = array();
+
+		// Establish necessary support classes
+		$obj = new stdClass;
+		$classes = array(
+			'config' => 'cfg',
+			'load' => 'load',
+			'input' => 'in'
+		);
+		foreach ($classes as $name => $abbr) {
+			$class = $this->ci_core_class($abbr);
+			$obj->$name = new $class;
+		}
+		$this->ci_instance($obj);
+
+		// Attach session instance locally
+		$config = array(
+			'sess_encrypt_cookie' => FALSE,
+			'sess_use_database' => FALSE,
+			'sess_table_name' => '',
+			'sess_expiration' => 7200,
+			'sess_expire_on_close' => FALSE,
+			'sess_match_ip' => FALSE,
+			'sess_match_useragent' => TRUE,
+			'sess_cookie_name' => 'ci_session',
+			'cookie_path' => '',
+			'cookie_domain' => '',
+			'cookie_secure' => FALSE,
+			'cookie_httponly' => FALSE,
+			'sess_time_to_update' => 300,
+			'time_reference' => 'local',
+			'cookie_prefix' => '',
+			'encryption_key' => 'foobar',
+			'sess_valid_drivers' => array(
+				'Mock_Libraries_Session_native',
+			   	'Mock_Libraries_Session_cookie'
+			)
+		);
+		$this->session = new Mock_Libraries_Session($config);
+	}
+
+	/**
+	 * Tear down test framework
+	 */
+	public function tear_down()
+	{
+		// Restore environment
+		if (session_id()) session_destroy();
+		$_SESSION = array();
+		$_COOKIE = $this->cookie_vals;
+
+		// Restore settings
+		foreach ($this->settings as $name => $value) {
+			ini_set('session.'.$name, $this->setting_vals[$name]);
+		}
+	}
+
+	/**
+	 * Test set_userdata() function
+	 *
+	 * @covers  CI_Session::set_userdata
+	 * @covers  CI_Session::userdata
+	 */
+	public function test_set_userdata()
+	{
+		// Set userdata values for each driver
+		$key1 = 'test1';
+		$ckey2 = 'test2';
+		$nkey2 = 'test3';
+		$cmsg1 = 'Some test data';
+		$cmsg2 = 42;
+		$nmsg1 = 'Other test data';
+		$nmsg2 = true;
+		$this->session->cookie->set_userdata($key1, $cmsg1);
+		$this->session->set_userdata($ckey2, $cmsg2);
+		$this->session->native->set_userdata($key1, $nmsg1);
+		$this->session->set_userdata($nkey2, $nmsg2);
+
+		// Verify independent messages
+		$this->assertEquals($cmsg1, $this->session->cookie->userdata($key1));
+		$this->assertEquals($nmsg1, $this->session->native->userdata($key1));
+
+		// Verify pre-selected driver sets
+		$this->assertEquals($cmsg2, $this->session->cookie->userdata($ckey2));
+		$this->assertEquals($nmsg2, $this->session->native->userdata($nkey2));
+
+		// Verify no crossover
+		$this->assertNull($this->session->cookie->userdata($nkey2));
+		$this->assertNull($this->session->native->userdata($ckey2));
+	}
+
+	/**
+	 * Test the has_userdata() function
+	 *
+	 * @covers	CI_Session::has_userdata
+	 */
+	public function test_has_userdata()
+	{
+		// Set a userdata value for each driver
+		$key = 'hastest';
+		$cmsg = 'My test data';
+		$this->session->cookie->set_userdata($key, $cmsg);
+		$nmsg = 'Your test data';
+		$this->session->native->set_userdata($key, $nmsg);
+
+		// Verify values exist
+		$this->assertTrue($this->session->cookie->has_userdata($key));
+		$this->assertTrue($this->session->native->has_userdata($key));
+
+		// Verify non-existent values
+		$nokey = 'hasnot';
+		$this->assertFalse($this->session->cookie->has_userdata($nokey));
+		$this->assertFalse($this->session->native->has_userdata($nokey));
+	}
+
+	/**
+	 * Test the all_userdata() function
+	 *
+	 * @covers	CI_Session::all_userdata
+	 */
+	public function test_all_userdata()
+	{
+		// Set a specific series of data for each driver
+		$cdata = array(
+			'one' => 'first',
+			'two' => 'second',
+		   	'three' => 'third',
+		   	'foo' => 'bar',
+		   	'bar' => 'baz'
+		);
+		$ndata = array(
+			'one' => 'gold',
+		   	'two' => 'silver',
+		   	'three' => 'bronze',
+		   	'foo' => 'baz',
+		   	'bar' => 'foo'
+		);
+		$this->session->cookie->set_userdata($cdata);
+		$this->session->native->set_userdata($ndata);
+
+		// Make sure all values are present
+		$call = $this->session->cookie->all_userdata();
+		foreach ($cdata as $key => $value) {
+			$this->assertEquals($value, $call[$key]);
+		}
+		$nall = $this->session->native->all_userdata();
+		foreach ($ndata as $key => $value) {
+			$this->assertEquals($value, $nall[$key]);
+		}
+	}
+
+	/**
+	 * Test the unset_userdata() function
+	 *
+	 * @covers	CI_Session::unset_userdata
+	 */
+	public function test_unset_userdata()
+	{
+		// Set a userdata message for each driver
+		$key = 'untest';
+		$cmsg = 'Other test data';
+		$this->session->cookie->set_userdata($key, $cmsg);
+		$nmsg = 'Sundry test data';
+		$this->session->native->set_userdata($key, $nmsg);
+
+		// Verify independent messages
+		$this->assertEquals($this->session->cookie->userdata($key), $cmsg);
+		$this->assertEquals($this->session->native->userdata($key), $nmsg);
+
+		// Unset them and verify absence
+		$this->session->cookie->unset_userdata($key);
+		$this->session->native->unset_userdata($key);
+		$this->assertNull($this->session->cookie->userdata($key));
+		$this->assertNull($this->session->native->userdata($key));
+	}
+
+	/**
+	 * Test the flashdata() functions
+	 *
+	 * @covers	CI_Session::set_flashdata
+	 * @covers	CI_Session::flashdata
+	 */
+	public function test_flashdata()
+	{
+		// Set flashdata message for each driver
+		$key = 'fltest';
+		$cmsg = 'Some flash data';
+		$this->session->cookie->set_flashdata($key, $cmsg);
+		$nmsg = 'Other flash data';
+		$this->session->native->set_flashdata($key, $nmsg);
+
+		// Simulate page reload
+		$this->session->cookie->reload();
+		$this->session->native->reload();
+
+		// Verify independent messages
+		$this->assertEquals($cmsg, $this->session->cookie->flashdata($key));
+		$this->assertEquals($nmsg, $this->session->native->flashdata($key));
+
+		// Simulate next page reload
+		$this->session->cookie->reload();
+		$this->session->native->reload();
+
+		// Verify absence of messages
+		$this->assertNull($this->session->cookie->flashdata($key));
+		$this->assertNull($this->session->native->flashdata($key));
+	}
+
+	/**
+	 * Test the keep_flashdata() function
+	 *
+	 * @covers	CI_Session::keep_flashdata
+	 */
+	public function test_keep_flashdata()
+	{
+		// Set flashdata message for each driver
+		$key = 'kfltest';
+		$cmsg = 'My flash data';
+		$this->session->cookie->set_flashdata($key, $cmsg);
+		$nmsg = 'Your flash data';
+		$this->session->native->set_flashdata($key, $nmsg);
+
+		// Simulate page reload and verify independent messages
+		$this->session->cookie->reload();
+		$this->session->native->reload();
+		$this->assertEquals($cmsg, $this->session->cookie->flashdata($key));
+		$this->assertEquals($nmsg, $this->session->native->flashdata($key));
+
+		// Keep messages
+		$this->session->cookie->keep_flashdata($key);
+		$this->session->native->keep_flashdata($key);
+
+		// Simulate next page reload and verify message persistence
+		$this->session->cookie->reload();
+		$this->session->native->reload();
+		$this->assertEquals($cmsg, $this->session->cookie->flashdata($key));
+		$this->assertEquals($nmsg, $this->session->native->flashdata($key));
+
+		// Simulate next page reload and verify absence of messages
+		$this->session->cookie->reload();
+		$this->session->native->reload();
+		$this->assertNull($this->session->cookie->flashdata($key));
+		$this->assertNull($this->session->native->flashdata($key));
+	}
+
+	/**
+	 * Test the all_flashdata() function
+	 *
+	 * @covers	CI_Session::all_flashdata
+	 */
+	public function test_all_flashdata()
+	{
+		// Set a specific series of data for each driver
+		$cdata = array(
+			'one' => 'first',
+		   	'two' => 'second',
+		   	'three' => 'third',
+		   	'foo' => 'bar',
+		   	'bar' => 'baz'
+		);
+		$ndata = array(
+			'one' => 'gold',
+		   	'two' => 'silver',
+		   	'three' => 'bronze',
+		   	'foo' => 'baz',
+		   	'bar' => 'foo'
+		);
+		$this->session->cookie->set_flashdata($cdata);
+		$this->session->native->set_flashdata($ndata);
+
+		// Simulate page reload and make sure all values are present
+		$this->session->cookie->reload();
+		$this->session->native->reload();
+		$this->assertEquals($cdata, $this->session->cookie->all_flashdata());
+		$this->assertEquals($ndata, $this->session->native->all_flashdata());
+	}
+
+	/**
+	 * Test the tempdata() functions
+	 *
+	 * @covers	CI_Session::set_tempdata
+	 * @covers	CI_Session::tempdata
+	 */
+	public function test_set_tempdata()
+	{
+		// Set tempdata message for each driver - 1 second timeout
+		$key = 'tmptest';
+		$cmsg = 'Some temp data';
+		$this->session->cookie->set_tempdata($key, $cmsg, 1);
+		$nmsg = 'Other temp data';
+		$this->session->native->set_tempdata($key, $nmsg, 1);
+
+		// Simulate page reload and verify independent messages
+		$this->session->cookie->reload();
+		$this->session->native->reload();
+		$this->assertEquals($cmsg, $this->session->cookie->tempdata($key));
+		$this->assertEquals($nmsg, $this->session->native->tempdata($key));
+
+		// Wait 2 seconds, simulate page reload and verify message absence
+		sleep(2);
+		$this->session->cookie->reload();
+		$this->session->native->reload();
+		$this->assertNull($this->session->cookie->tempdata($key));
+		$this->assertNull($this->session->native->tempdata($key));
+	}
+
+	/**
+	 * Test the unset_tempdata() function
+	 *
+	 * @covers	CI_Session::unset_tempdata
+	 */
+	public function test_unset_tempdata()
+	{
+		// Set tempdata message for each driver - 1 second timeout
+		$key = 'utmptest';
+		$cmsg = 'My temp data';
+		$this->session->cookie->set_tempdata($key, $cmsg, 1);
+		$nmsg = 'Your temp data';
+		$this->session->native->set_tempdata($key, $nmsg, 1);
+
+		// Verify independent messages
+		$this->assertEquals($cmsg, $this->session->cookie->tempdata($key));
+		$this->assertEquals($nmsg, $this->session->native->tempdata($key));
+
+		// Unset data and verify message absence
+		$this->session->cookie->unset_tempdata($key);
+		$this->session->native->unset_tempdata($key);
+		$this->assertNull($this->session->cookie->tempdata($key));
+		$this->assertNull($this->session->native->tempdata($key));
+	}
+
+	/**
+	 * Test the sess_regenerate() function
+	 *
+	 * @covers	CI_Session::sess_regenerate
+	 */
+	public function test_sess_regenerate()
+	{
+		// Get current session id, regenerate, and compare
+		// Cookie driver
+		$oldid = $this->session->cookie->userdata('session_id');
+		$this->session->cookie->sess_regenerate();
+		$newid = $this->session->cookie->userdata('session_id');
+		$this->assertNotEquals($oldid, $newid);
+
+		// Native driver - bug #55267 (https://bugs.php.net/bug.php?id=55267) prevents testing this
+		// $oldid = session_id();
+		// $this->session->native->sess_regenerate();
+		// $oldid = session_id();
+		// $this->assertNotEquals($oldid, $newid);
+	}
+
+	/**
+	 * Test the sess_destroy() function
+	 *
+	 * @covers	CI_Session::sess_destroy
+	 */
+	public function test_sess_destroy()
+	{
+		// Set a userdata message, destroy session, and verify absence
+		$key = 'dsttest';
+		$msg = 'More test data';
+
+		// Cookie driver
+		$this->session->cookie->set_userdata($key, $msg);
+		$this->assertEquals($msg, $this->session->cookie->userdata($key));
+		$this->session->cookie->sess_destroy();
+		$this->assertNull($this->session->cookie->userdata($key));
+
+		// Native driver
+		$this->session->native->set_userdata($key, $msg);
+		$this->assertEquals($msg, $this->session->native->userdata($key));
+		$this->session->native->sess_destroy();
+		$this->assertNull($this->session->native->userdata($key));
+	}
+}
+
diff --git a/tests/mocks/autoloader.php b/tests/mocks/autoloader.php
index be1c2220c..88d016bba 100644
--- a/tests/mocks/autoloader.php
+++ b/tests/mocks/autoloader.php
@@ -26,10 +26,14 @@ function autoload($class)
 		'Email', 'Encrypt', 'Form_validation',
 		'Ftp', 'Image_lib', 'Javascript',
 		'Log', 'Migration', 'Pagination',
-		'Parser', 'Profiler', 'Session',
-		'Table', 'Trackback', 'Typography',
-		'Unit_test', 'Upload', 'User_agent',
-		'Xmlrpc', 'Zip',
+		'Parser', 'Profiler', 'Table',
+	   	'Trackback', 'Typography', 'Unit_test',
+	   	'Upload', 'User_agent', 'Xmlrpc',
+	   	'Zip',
+	);
+
+	$ci_drivers = array(
+		'Session',
 	);
 
 	if (strpos($class, 'Mock_') === 0)
@@ -52,6 +56,15 @@ function autoload($class)
 			$dir = BASEPATH.'libraries'.DIRECTORY_SEPARATOR;
 			$class = ($subclass === 'Driver_Library') ? 'Driver' : $subclass;
 		}
+		elseif (in_array($subclass, $ci_drivers))
+		{
+			$dir = BASEPATH.'libraries'.DIRECTORY_SEPARATOR.$subclass.DIRECTORY_SEPARATOR;
+			$class = $subclass;
+		}
+		elseif (in_array(($parent = strtok($subclass, '_')), $ci_drivers)) {
+			$dir = BASEPATH.'libraries'.DIRECTORY_SEPARATOR.$parent.DIRECTORY_SEPARATOR.'drivers'.DIRECTORY_SEPARATOR;
+			$class = $subclass;
+		}
 		elseif (preg_match('/^CI_DB_(.+)_(driver|forge|result|utility)$/', $class, $m) && count($m) === 3)
 		{
 			$driver_path = BASEPATH.'database'.DIRECTORY_SEPARATOR.'drivers'.DIRECTORY_SEPARATOR;
@@ -91,4 +104,4 @@ function autoload($class)
 	}
 
 	include_once($file);
-}
\ No newline at end of file
+}
diff --git a/tests/mocks/libraries/session.php b/tests/mocks/libraries/session.php
new file mode 100644
index 000000000..9d6feee42
--- /dev/null
+++ b/tests/mocks/libraries/session.php
@@ -0,0 +1,43 @@
+<?php
+
+/**
+ * Mock library to add testing features to Session driver library
+ */
+class Mock_Libraries_Session extends CI_Session {
+	/**
+	 * Simulate new page load
+	 */
+	public function reload()
+	{
+		$this->_flashdata_sweep();
+		$this->_flashdata_mark();
+		$this->_tempdata_sweep();
+	}
+}
+
+/**
+ * Mock cookie driver to overload cookie setting
+ */
+class Mock_Libraries_Session_cookie extends CI_Session_cookie {
+	/**
+	 * Overload _setcookie to manage $_COOKIE values, since actual cookies can't be set in unit testing
+	 */
+	protected function _setcookie($name, $value = '', $expire = 0, $path = '', $domain = '', $secure = false,
+	$httponly = false)
+	{
+		if (empty($value) || $expire <= time()) {
+			// Clear cookie
+			unset($_COOKIE[$name]);
+		}
+		else {
+			// Set cookie
+			$_COOKIE[$name] = $value;
+		}
+	}
+}
+
+/**
+ * Mock native driver (just for consistency in loading)
+ */
+class Mock_Libraries_Session_native extends CI_Session_native { }
+
diff --git a/user_guide_src/source/index.rst b/user_guide_src/source/index.rst
index e42425bab..35089703f 100644
--- a/user_guide_src/source/index.rst
+++ b/user_guide_src/source/index.rst
@@ -80,6 +80,7 @@ Driver Reference
 - :doc:`libraries/caching`
 - :doc:`database/index`
 - :doc:`libraries/javascript`
+- :doc:`libraries/sessions`
 
 ****************
 Helper Reference
@@ -119,4 +120,4 @@ Contributing to CodeIgniter
 	documentation/index
 	tutorial/index
 	general/quick_reference
-	general/credits
\ No newline at end of file
+	general/credits
diff --git a/user_guide_src/source/libraries/loader.rst b/user_guide_src/source/libraries/loader.rst
index aadf9740a..33c1bafec 100644
--- a/user_guide_src/source/libraries/loader.rst
+++ b/user_guide_src/source/libraries/loader.rst
@@ -4,6 +4,7 @@ Loader Class
 
 Loader, as the name suggests, is used to load elements. These elements
 can be libraries (classes) :doc:`View files <../general/views>`,
+:doc:`Drivers <../general/drivers>`,
 :doc:`Helpers <../general/helpers>`,
 :doc:`Models <../general/models>`, or your own files.
 
@@ -74,6 +75,70 @@ Assigning a Library to a different object name
 
 If the third (optional) parameter is blank, the library will usually be
 assigned to an object with the same name as the library. For example, if
+the library is named Calendar, it will be assigned to a variable named
+$this->calendar.
+
+If you prefer to set your own class names you can pass its value to the
+third parameter::
+
+	$this->load->library('calendar', '', 'my_calendar');
+
+	// Calendar class is now accessed using:
+
+	$this->my_calendar
+
+Please take note, when multiple libraries are supplied in an array for
+the first parameter, this parameter is discarded.
+
+$this->load->driver('parent_name', $config, 'object name')
+===========================================================
+
+This function is used to load driver libraries. Where parent_name is the
+name of the parent class you want to load.
+
+As an example, if you would like to use sessions with CodeIgniter, the first
+step is to load the session driver within your controller::
+
+	$this->load->driver('session');
+
+Once loaded, the library will be ready for use, using
+$this->session->*some_function*().
+
+Driver files must be stored in a subdirectory within the main
+"libraries" folder, or within your personal application/libraries
+folder. The subdirectory must match the parent class name. Read the
+:doc:`Drivers <../general/drivers>` description for details.
+
+Additionally, multiple driver libraries can be loaded at the same time by
+passing an array of drivers to the load function.
+
+::
+
+	$this->load->driver(array('session', 'cache'));
+
+Setting options
+---------------
+
+The second (optional) parameter allows you to optionally pass
+configuration settings. You will typically pass these as an array::
+
+	$config = array (
+	                  'sess_driver' => 'cookie',
+	                  'sess_encrypt_cookie'  => true,
+	                  'encryption_key' => 'mysecretkey'
+	               );
+
+	$this->load->driver('session', $config);
+
+Config options can usually also be set via a config file. Each library
+is explained in detail in its own page, so please read the information
+regarding each one you would like to use.
+
+Assigning a Driver to a different object name
+----------------------------------------------
+
+If the third (optional) parameter is blank, the library will be assigned
+to an object with the same name as the parent class. For example, if
 the library is named Session, it will be assigned to a variable named
 $this->session.
 
@@ -86,8 +151,8 @@ third parameter::
 
 	$this->my_session
 
-Please take note, when multiple libraries are supplied in an array for
-the first parameter, this parameter is discarded.
+.. note:: Driver libraries may also be loaded with the library() method,
+	but it is faster to use driver()
 
 $this->load->view('file_name', $data, true/false)
 ==================================================
@@ -281,4 +346,4 @@ calling add_package_path().
 	// Again without the second parameter:
 	$this->load->add_package_path(APPPATH.'my_app', TRUE);
 	$this->load->view('my_app_index'); // Loads
-	$this->load->view('welcome_message'); // Loads
\ No newline at end of file
+	$this->load->view('welcome_message'); // Loads
diff --git a/user_guide_src/source/libraries/sessions.rst b/user_guide_src/source/libraries/sessions.rst
index 5400524a9..dd9e8cbb4 100644
--- a/user_guide_src/source/libraries/sessions.rst
+++ b/user_guide_src/source/libraries/sessions.rst
@@ -1,29 +1,19 @@
-#############
-Session Class
-#############
+##############
+Session Driver
+##############
 
 The Session class permits you maintain a user's "state" and track their
-activity while they browse your site. The Session class stores session
-information for each user as serialized (and optionally encrypted) data
-in a cookie. It can also store the session data in a database table for
-added security, as this permits the session ID in the user's cookie to
-be matched against the stored session ID. By default only the cookie is
-saved. If you choose to use the database option you'll need to create
-the session table as indicated below.
-
-.. note:: The Session class does **not** utilize native PHP sessions. It
-	generates its own session data, offering more flexibility for
-	developers.
-
-.. note:: Even if you are not using encrypted sessions, you must set
-	an :doc:`encryption key <./encryption>` in your config file which is used
-	to aid in preventing session data manipulation.
+activity while they browse your site. CodeIgniter offers two default
+session drivers: the classic `Cookie Driver`_, and the `Native Driver`_,
+which supports usage of the native PHP Session mechanism. In addition,
+you may create your own `Custom Drivers`_ to store session data however
+you wish, while still taking advantage of the features of the Session class.
 
 Initializing a Session
 ======================
 
 Sessions will typically run globally with each page load, so the session
-class must either be :doc:`initialized <../general/libraries>` in your
+class must either be :doc:`initialized <../general/drivers>` in your
 :doc:`controller <../general/controllers>` constructors, or it can be
 :doc:`auto-loaded <../general/autoloader>` by the system. For the most
 part the session class will run unattended in the background, so simply
@@ -31,22 +21,25 @@ initializing the class will cause it to read, create, and update
 sessions.
 
 To initialize the Session class manually in your controller constructor,
-use the $this->load->library function::
+use the $this->load->driver function::
 
-	$this->load->library('session');
+	$this->load->driver('session');
 
 Once loaded, the Sessions library object will be available using:
 $this->session
 
+.. note:: For backward compatibility, the Session class may stil be loaded
+	using the $this->load->library function, but converting your applications
+	to use $this->load->driver is strongly recommended.
+
 How do Sessions work?
 =====================
 
 When a page is loaded, the session class will check to see if valid
-session data exists in the user's session cookie. If sessions data does
-**not** exist (or if it has expired) a new session will be created and
-saved in the cookie. If a session does exist, its information will be
-updated and the cookie will be updated. With each update, the
-session_id will be regenerated.
+session data exists in the user's session. If sessions data does **not**
+exist (or if it has expired) a new session will be created and saved.
+If a session does exist, its information will be updated. With each update,
+the session_id will be regenerated.
 
 It's important for you to understand that once initialized, the Session
 class runs automatically. There is nothing you need to do to cause the
@@ -79,19 +72,12 @@ prototype::
 	     'last_activity' => timestamp
 	)
 
-If you have the encryption option enabled, the serialized array will be
-encrypted before being stored in the cookie, making the data highly
-secure and impervious to being read or altered by someone. More info
-regarding encryption can be :doc:`found here <encryption>`, although
-the Session class will take care of initializing and encrypting the data
-automatically.
-
-Note: Session cookies are only updated every five minutes by default to
-reduce processor load. If you repeatedly reload a page you'll notice
-that the "last activity" time only updates if five minutes or more has
-passed since the last time the cookie was written. This time is
-configurable by changing the $config['sess_time_to_update'] line in
-your system/config/config.php file.
+.. note:: Sessions are only updated every five minutes by default to
+	reduce processor load. If you repeatedly reload a page you'll notice
+	that the "last activity" time only updates if five minutes or more has
+	passed since the last time the cookie was written. This time is
+	configurable by changing the $config['sess_time_to_update'] line in
+	your system/config/config.php file.
 
 Retrieving Session Data
 =======================
@@ -106,7 +92,7 @@ fetch. For example, to fetch the session ID you will do this::
 
 	$session_id = $this->session->userdata('session_id');
 
-.. note:: The function returns FALSE (boolean) if the item you are
+.. note:: The function returns NULL if the item you are
 	trying to access does not exist.
 
 Adding Custom Session Data
@@ -117,7 +103,7 @@ to it and it will be stored in the user's cookie. Why would you want to
 do this? Here's one example:
 
 Let's say a particular user logs into your site. Once authenticated, you
-could add their username and email address to the session cookie, making
+could add their username and email address to the session, making
 that data globally available to you without having to run a database
 query when you need it.
 
@@ -144,11 +130,11 @@ supports this syntax.
 
 	$this->session->set_userdata('some_name', 'some_value');
 
+If you want to verify that a userdata value exists, call has_userdata().
 
-.. note:: Cookies can only hold 4KB of data, so be careful not to exceed
-	the capacity. The encryption process in particular produces a longer
-	data string than the original so keep careful track of how much data you
-	are storing.
+::
+
+	$this->session->has_userdata('some_name');
 
 Retrieving All Session Data
 ===========================
@@ -195,8 +181,8 @@ available for the next server request, and are then automatically
 cleared. These can be very useful, and are typically used for
 informational or status messages (for example: "record 2 deleted").
 
-Note: Flash variables are prefaced with "flash\_" so avoid this prefix
-in your own session names.
+.. note:: Flash variables are prefaced with "flash\_" so avoid this prefix
+	in your own session names.
 
 To add flashdata::
 
@@ -222,9 +208,162 @@ additional request, you can do so using the keep_flashdata() function.
 
 	$this->session->keep_flashdata('item');
 
+Tempdata
+========
+
+CodeIgniter also supports "tempdata", or session data with a specific
+expiration time. After the value expires, or the session expires or is
+deleted, the value is automatically removed.
+
+To add tempdata::
+
+	$expire = 300;	// Expire in 5 minutes
+
+	$this->session->set_tempdata('item', 'value', $expire);
+
+You can also pass an array to set_tempdata()::
+
+	$tempdata = array('newuser' => TRUE, 'message' => 'Thanks for joining!');
+
+	$this->session->set_tempdata($tempdata, '', $expire);
+
+.. note:: If the expiration is omitted or set to 0, the default expiration of
+	5 minutes will be used.
+
+To read a tempdata variable::
+
+	$this->session->tempdata('item');
+
+If you need to remove a tempdata value before it expires,
+use unset_tempdata()::
+
+	$this->session->unset_tempdata('item');
+
+Destroying a Session
+====================
+
+To clear the current session::
+
+	$this->session->sess_destroy();
+
+.. note:: This function should be the last one called, and even flash
+	variables will no longer be available. If you only want some items
+	destroyed and not all, use unset_userdata().
+
+Session Preferences
+===================
+
+You'll find the following Session related preferences in your
+application/config/config.php file:
+
+=========================== =============== =========================== ==========================================================================
+Preference                  Default         Options                     Description
+=========================== =============== =========================== ==========================================================================
+**sess_driver**             cookie          cookie/native/*custom*      The initial session driver to load.
+**sess_valid_drivers**      cookie, native  None                        Additional valid drivers which may be loaded.
+**sess_cookie_name**        ci_session      None                        The name you want the session cookie saved as (data for Cookie driver or
+                                                                        session ID for Native driver).
+**sess_expiration**         7200            None                        The number of seconds you would like the session to last. The default
+                                                                        value is 2 hours (7200 seconds). If you would like a non-expiring
+                                                                        session set the value to zero: 0
+**sess_expire_on_close**    FALSE           TRUE/FALSE (boolean)        Whether to cause the session to expire automatically when the browser
+                                                                        window is closed.
+**sess_encrypt_cookie**     FALSE           TRUE/FALSE (boolean)        Whether to encrypt the session data (Cookie driver only).
+**sess_use_database**       FALSE           TRUE/FALSE (boolean)        Whether to save the session data to a database. You must create the
+                                                                        table before enabling this option (Cookie driver only).
+**sess_table_name**         ci_sessions     Any valid SQL table name    The name of the session database table (Cookie driver only).
+**sess_time_to_update**     300             Time in seconds             This options controls how often the session class will regenerate itself
+                                                                        and create a new session id.
+**sess_match_ip**           FALSE           TRUE/FALSE (boolean)        Whether to match the user's IP address when reading the session data.
+                                                                        Note that some ISPs dynamically changes the IP, so if you want a
+                                                                        non-expiring session you will likely set this to FALSE.
+**sess_match_useragent**    TRUE            TRUE/FALSE (boolean)        Whether to match the User Agent when reading the session data.
+=========================== =============== =========================== ==========================================================================
+
+In addition to the values above, the cookie and native drivers apply the
+following configuration values shared by the :doc:`Input <input>` and
+:doc:`Security <security>` classes:
+
+=========================== =============== ==========================================================================
+Preference                  Default         Description
+=========================== =============== ==========================================================================
+**cookie_prefix**           ''              Set a cookie name prefix in order to avoid name collisions
+**cookie_domain**           ''              The domain for which the session is applicable
+**cookie_path**             /               The path to which the session is applicable
+=========================== =============== ==========================================================================
+
+Session Drivers
+===============
+
+By default, the `Cookie Driver`_ is loaded when a session is initialized.
+However, any valid driver may be selected with the $config['sess_driver']
+line in your config.php file.
+
+The session driver library comes with the cookie and native drivers
+installed, and `Custom Drivers`_ may also be installed by the user.
+
+Typically, only one driver will be used at a time, but CodeIgniter does
+support loading multiple drivers. If a specific valid driver is called, it
+will be automatically loaded. Or, an additional driver may be explicitly
+loaded by calling load_driver()::
+
+	$this->session->load_driver('native');
+
+The Session library keeps track of the most recently selected driver to call
+for driver methods. Normally, session class methods are called directly on
+the parent class, as illustrated above. However, any methods called through
+a specific driver will select that driver before invoking the parent method.
+
+So, alternation between multiple drivers can be achieved by specifying which
+driver to use for each call::
+
+	$this->session->native->set_userdata('foo', 'bar');
+
+	$this->session->cookie->userdata('foo');
+
+	$this->session->native->unset_userdata('foo');
+
+Notice in the previous example that the *native* userdata value 'foo'
+would be set to 'bar', which would NOT be returned by the call for
+the *cookie* userdata 'foo', nor would the *cookie* value be unset by
+the call to unset the *native* 'foo' value. The drivers maintain independent
+sets of values, regardless of key names.
+
+A specific driver may also be explicitly selected for use by pursuant
+methods with the select_driver() call::
+
+	$this->session->select_driver('native');
+
+	$this->session->userdata('item');	// Uses the native driver
+
+Cookie Driver
+-------------
+
+The Cookie driver stores session information for each user as serialized
+(and optionally encrypted) data in a cookie. It can also store the session
+data in a database table for added security, as this permits the session ID
+in the user's cookie to be matched against the stored session ID. By default
+only the cookie is saved. If you choose to use the database option you'll
+need to create the session table as indicated below.
+
+If you have the encryption option enabled, the serialized array will be
+encrypted before being stored in the cookie, making the data highly
+secure and impervious to being read or altered by someone. More info
+regarding encryption can be :doc:`found here <encryption>`, although
+the Session class will take care of initializing and encrypting the data
+automatically.
+
+.. note:: Even if you are not using encrypted sessions, you must set
+	an :doc:`encryption key <./encryption>` in your config file which is used
+	to aid in preventing session data manipulation.
+
+.. note:: Cookies can only hold 4KB of data, so be careful not to exceed
+	the capacity. The encryption process in particular produces a longer
+	data string than the original so keep careful track of how much data you
+	are storing.
 
 Saving Session Data to a Database
-=================================
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 While the session data array stored in the user's cookie contains a
 Session ID, unless you store session data in a database there is no way
@@ -267,44 +406,83 @@ session class::
 
 		$config['sess_table_name'] = 'ci_sessions';
 
-.. note:: The Session class has built-in garbage collection which clears
+.. note:: The Cookie driver has built-in garbage collection which clears
 	out expired sessions so you do not need to write your own routine to do
 	it.
 
-Destroying a Session
-====================
+Native Driver
+-------------
 
-To clear the current session::
+The Native driver relies on native PHP sessions to store data in the
+$_SESSION superglobal array. All stored values continue to be available
+through $_SESSION, but flash- and temp- data items carry special prefixes.
 
-	$this->session->sess_destroy();
+Custom Drivers
+--------------
 
-.. note:: This function should be the last one called, and even flash
-	variables will no longer be available. If you only want some items
-	destroyed and not all, use unset_userdata().
+You may also :doc:`create your own <../general/creating_drivers>` custom
+session drivers. A session driver basically manages an array of name/value
+pairs with some sort of storage mechanism.
 
-Session Preferences
-===================
+To make a new driver, extend CI_Session_driver. Overload the initialize()
+method and read or create session data. Then implement a save handler to
+write changed data to storage (sess_save), a destroy handler to remove
+deleted data (sess_destroy), a regenerate handler to make a new session ID
+(sess_regenerate), and an access handler to expose the data (get_userdata).
+Your initial class might look like::
 
-You'll find the following Session related preferences in your
-application/config/config.php file:
+	class CI_Session_custom extends CI_Session_driver {
+		protected function initialize()
+		{
+			// Read existing session data or create a new one
+		}
+
+		public function sess_save()
+		{
+			// Save current data to storage
+		}
+
+		public function sess_destroy()
+		{
+			// Destroy the current session and clean up storage
+		}
+
+		public function sess_regenerate()
+		{
+			// Create new session ID
+		}
+
+		public function &get_userdata()
+		{
+			// Return a reference to your userdata array
+		}
+	}
+
+Notice that get_userdata() returns a reference so the parent library is
+accessing the same array the driver object is using. This saves memory
+and avoids synchronization issues during usage.
+
+Put your driver in the libraries/Session/drivers folder anywhere in your
+package paths. This includes the application directory, the system directory,
+or any path you add with $CI->load->add_package_path(). Your driver must be
+named CI_Session_<name>, and your filename must be Session_<name>.php,
+preferably also capitalized, such as::
+
+	CI_Session_foo in libraries/Session/drivers/Session_foo.php
+
+Then specify the driver by setting 'sess_driver' in your config.php file or as a
+parameter when loading the CI_Session object::
+
+	$config['sess_driver'] = 'foo';
+
+OR::
+
+	$CI->load->driver('session', array('sess_driver' => 'foo'));
+
+The driver specified by 'sess_driver' is automatically included as a valid
+driver. However, if you want to make a custom driver available as an option
+without making it the initially loaded driver, set 'sess_valid_drivers' in
+your config.php file to an array including your driver name::
+
+	$config['sess_valid_drivers'] = array('sess_driver');
 
-=========================== =============== =========================== ==========================================================================
-Preference                  Default         Options                     Description
-=========================== =============== =========================== ==========================================================================
-**sess_cookie_name**        ci_session      None                        The name you want the session cookie saved as.
-**sess_expiration**         7200            None                        The number of seconds you would like the session to last. The default
-                                                                        value is 2 hours (7200 seconds). If you would like a non-expiring
-                                                                        session set the value to zero: 0
-**sess_expire_on_close**    FALSE           TRUE/FALSE (boolean)        Whether to cause the session to expire automatically when the browser
-                                                                        window is closed.
-**sess_encrypt_cookie**     FALSE           TRUE/FALSE (boolean)        Whether to encrypt the session data.
-**sess_use_database**       FALSE           TRUE/FALSE (boolean)        Whether to save the session data to a database. You must create the
-                                                                        table before enabling this option.
-**sess_table_name**         ci_sessions     Any valid SQL table name    The name of the session database table.
-**sess_time_to_update**     300             Time in seconds             This options controls how often the session class will regenerate itself
-                                                                        and create a new session id.
-**sess_match_ip**           FALSE           TRUE/FALSE (boolean)        Whether to match the user's IP address when reading the session data.
-                                                                        Note that some ISPs dynamically changes the IP, so if you want a
-                                                                        non-expiring session you will likely set this to FALSE.
-**sess_match_useragent**    TRUE            TRUE/FALSE (boolean)        Whether to match the User Agent when reading the session data.
-=========================== =============== =========================== ==========================================================================
\ No newline at end of file