/manage/expressionengine/libraries/Remember.php

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**
 * ExpressionEngine - by EllisLab
 *
 * @package		ExpressionEngine
 * @author		EllisLab Dev Team
 * @copyright	Copyright (c) 2003 - 2011, EllisLab, Inc.
 * @license		http://ellislab.com/expressionengine/user-guide/license.html
 * @link		http://ellislab.com
 * @since		Version 2.4
 * @filesource
 */
 
// ------------------------------------------------------------------------

/**
 * ExpressionEngine Core Remember Me Class
 *
 * @package		ExpressionEngine
 * @subpackage	Core
 * @category	Core
 * @author		EllisLab Dev Team
 * @link		http://ellislab.com
 */
class Remember {

	private $max_per_site = 5;			// remembers per site per user
	private $gc_probability = 10;		// percentage of logins that gc
	
	protected $table = 'remember_me';

	protected $data = NULL;
	protected $cookie = 'remember';
	protected $cookie_value = FALSE;
	
	protected $ip_address = '';
	protected $user_agent = '';
	
	protected $EE;

	/**
	 * Constructor
	 *
	 * @access	public
	 */
	function __construct()
	{
		$this->EE =& get_instance();
		
		$this->cookie_value = $this->EE->input->cookie($this->cookie);
		
		$this->ip_address = $this->EE->input->ip_address();
		$this->user_agent = substr($this->EE->input->user_agent(), 0, 120);
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Create a new remember me
	 *
	 * @return void
	 */
	public function create($expiration)
	{
		// this is a good time to check how many they have
		$active = $this->EE->db
			->order_by('last_refresh', 'ASC')
			->get_where($this->table, array(
				'member_id'		=> $this->EE->session->userdata('member_id'),
				'site_id'		=> $this->EE->config->item('site_id')
			))
			->result();
		
		$this->cookie_value = $this->_generate_id();
		
		$this->data = array(
			'remember_me_id'	=> $this->cookie_value,
			'member_id'			=> $this->EE->session->userdata('member_id'),
			'ip_address'		=> $this->ip_address,
			'user_agent'		=> $this->user_agent,
			'admin_sess'		=> $this->EE->session->userdata('admin_sess'),
			'site_id'			=> $this->EE->config->item('site_id'),
			'expiration'		=> $this->EE->localize->now + $expiration,
			'last_refresh'		=> $this->EE->localize->now
		);
		
		$this->EE->db->set($this->data);
		
		// If they have too many remembered sessions,
		// we replace their oldest one.
		if (count($active) >= $this->max_per_site)
		{
			$this->EE->db->where('remember_me_id', $active[0]->remember_me_id);
			$this->EE->db->update($this->table);
		}
		else
		{
			$this->EE->db->insert($this->table);
			$this->_garbage_collect();
		}
		
		$this->_set_cookie($this->data['remember_me_id'], $expiration);
	}
	
	// --------------------------------------------------------------------

	/**
	 * Check if a remember me cookie + valid data exists
	 *
	 * @return void
	 */
	public function exists()
	{
		if ($this->data === NULL)
		{
			$this->data = array();
			return $this->_validate_db();
		}
		
		return count($this->data);
	}

	// --------------------------------------------------------------------

	/**
	 * Remember me data accessor
	 *
	 * @return void
	 */
	public function data($key)
	{
		return (isset($this->data[$key])) ? $this->data[$key] : NULL;
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Clear the current remember me
	 *
	 * @return void
	 */
	public function delete()
	{
		if ($this->cookie_value)
		{
			$this->EE->db->where('remember_me_id', $this->cookie_value);
			$this->EE->db->delete($this->table);
		}
		
		$this->data = array();
		$this->_delete_cookie();
	}
	
	
	// --------------------------------------------------------------------
	
	/**
	 * Clear all remember me's except for the current one
	 *
	 * Used when changing passwords to disable old
	 * remember me's that may have been created with
	 * compromised credentials
	 *
	 * @return void
	 */
	public function delete_others()
	{
		$this->EE->db->where('member_id', $this->EE->session->userdata('member_id'));
		
		if ($this->cookie_value)
		{
			$this->EE->db->where('remember_me_id !=', $this->cookie_value);
		}
		
		$this->EE->db->delete($this->table);
	}

	// --------------------------------------------------------------------
	
	/**
	 * Get the remember me data in the db and validate it
	 *
	 * @return void
	 */
	public function refresh()
	{
		if ( ! $this->exists())
		{
			return;
		}
		
		$yesterday = $this->EE->localize->now - 60*60*24;
		
		if ($this->data['last_refresh'] < $yesterday)
		{
			$id = $this->_generate_id();
			
			// push the expiration date ahead by as much as we've lost
			$adjust_expire = $this->data['last_refresh'] - $this->EE->localize->now;
			
			// refresh all the data
			$this->data['last_refresh'] = $this->EE->localize->now;
			$this->data['remember_me_id'] = $id;
			$this->data['expiration'] += $adjust_expire;
			
			$this->EE->db->where('remember_me_id', $this->cookie_value)
				->set($this->data)
				->update($this->table);
						
			$expiration = $this->data['expiration'] - $this->EE->localize->now;
			$this->_set_cookie($id, $expiration);
		}
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Get the remember me data in the db and validate it
	 *
	 * @return bool
	 */
	protected function _validate_db()
	{
		if ( ! $this->cookie_value)
		{
			return FALSE;
		}
		
		// grab the db entry
		$rem_q = $this->EE->db->get_where($this->table, array(
			'remember_me_id' => $this->cookie_value
		));
		
		if ($rem_q->num_rows() != 1)
		{
			$this->_delete_cookie();
			return FALSE;
		}
		
		$rem_data = $rem_q->row_array();
		$rem_q->free_result();

		// validate browser markers
		if ($this->user_agent != $rem_data['user_agent'])
		{
			$this->_delete_cookie();
			return FALSE;
		}
		
		// validate time
		if ($rem_data['expiration'] < $this->EE->localize->now)
		{
			$this->_delete_cookie();
			return FALSE;			
		}
		
		// remember the data we grabbed (haha!)
		$this->data = $rem_data;
		return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	 * Generates a unique id
	 *
	 * @return string	random 40 character string
	 */
	protected function _generate_id()
	{
		return sha1(uniqid(mt_rand(), TRUE));
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Delete the remember me cookie
	 *
	 * @return void
	 */
	protected function _delete_cookie()
	{
		$this->cookie_value = FALSE;
		$this->EE->functions->set_cookie($this->cookie);
	}

	// --------------------------------------------------------------------
	
	/**
	 * Set the remember me cookie
	 *
	 * @return void
	 */
	protected function _set_cookie($value, $expiration)
	{
		$this->cookie_value = $value;
		$this->EE->functions->set_cookie($this->cookie, $value, $expiration);
	}
	
	// --------------------------------------------------------------------
	
	/**
	 * Garbage collect
	 *
	 * @return void
	 */
	protected function _garbage_collect()
	{		
		srand(time());
		
		if ((rand() % 100) < $this->gc_probability)
		{
			$last_year = $this->EE->localize->now - 60*60*24*365;
			
			$this->EE->db->where('expiration <', $this->EE->localize->now)
				->or_where('last_refresh <', $last_year)
				->delete($this->table);
			
		}
	}
}

// END Remember class


/* End of file Remember.php */
/* Location: ./system/expressionengine/libraries/Remember.php */