Initial commit

Signed-off-by: Florian Pritz <bluewind@xssn.at>

1 files changed, 758 insertions, 0 deletions

diff --git a/system/libraries/Session.php b/system/libraries/Session.php
new file mode 100644
index 000000000..5e0ce48e9
--- /dev/null
+++ b/system/libraries/Session.php
@@ -0,0 +1,758 @@
+<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package		CodeIgniter
+ * @author		ExpressionEngine Dev Team
+ * @copyright	Copyright (c) 2008 - 2009, EllisLab, Inc.
+ * @license		http://codeigniter.com/user_guide/license.html
+ * @link		http://codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * Session Class
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Sessions
+ * @author		ExpressionEngine Dev Team
+ * @link		http://codeigniter.com/user_guide/libraries/sessions.html
+ */
+class CI_Session {
+
+	var $sess_encrypt_cookie		= FALSE;
+	var $sess_use_database			= FALSE;
+	var $sess_table_name			= '';
+	var $sess_expiration			= 7200;
+	var $sess_match_ip				= FALSE;
+	var $sess_match_useragent		= TRUE;
+	var $sess_cookie_name			= 'ci_session';
+	var $cookie_prefix				= '';
+	var $cookie_path				= '';
+	var $cookie_domain				= '';
+	var $sess_time_to_update		= 300;
+	var $encryption_key				= '';
+	var $flashdata_key 				= 'flash';
+	var $time_reference				= 'time';
+	var $gc_probability				= 5;
+	var $userdata					= array();
+	var $CI;
+	var $now;
+
+	/**
+	 * Session Constructor
+	 *
+	 * The constructor runs the session routines automatically
+	 * whenever the class is instantiated.
+	 */
+	function CI_Session($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_match_ip', 'sess_match_useragent', 'sess_cookie_name', 'cookie_path', 'cookie_domain', 'sess_time_to_update', 'time_reference', 'cookie_prefix', 'encryption_key') as $key)
+		{
+			$this->$key = (isset($params[$key])) ? $params[$key] : $this->CI->config->item($key);
+		}
+
+		// 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 AND $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
+	 *
+	 * @access	public
+	 * @return	bool
+	 */
+	function sess_read()
+	{
+		// Fetch the cookie
+		$session = $this->CI->input->cookie($this->sess_cookie_name);
+
+		// No cookie?  Goodbye cruel world!...
+		if ($session === FALSE)
+		{
+			log_message('debug', 'A session cookie was not found.');
+			return FALSE;
+		}
+
+		// Decrypt the cookie data
+		if ($this->sess_encrypt_cookie == TRUE)
+		{
+			$session = $this->CI->encrypt->decode($session);
+		}
+		else
+		{
+			// encryption was not used, so we need to check the md5 hash
+			$hash	 = substr($session, strlen($session)-32); // get last 32 chars
+			$session = substr($session, 0, strlen($session)-32);
+
+			// Does the md5 hash match?  This is to prevent manipulation of session data in userspace
+			if ($hash !==  md5($session.$this->encryption_key))
+			{
+				log_message('error', 'The session cookie data did not match what was expected. This could be a possible hacking attempt.');
+				$this->sess_destroy();
+				return FALSE;
+			}
+		}
+
+		// Unserialize the session array
+		$session = $this->_unserialize($session);
+
+		// Is the session data we unserialized an array with the correct format?
+		if ( ! is_array($session) OR ! isset($session['session_id']) OR ! isset($session['ip_address']) OR ! isset($session['user_agent']) OR ! isset($session['last_activity']))
+		{
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Is the session current?
+		if (($session['last_activity'] + $this->sess_expiration) < $this->now)
+		{
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Does the IP Match?
+		if ($this->sess_match_ip == TRUE AND $session['ip_address'] != $this->CI->input->ip_address())
+		{
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Does the User Agent Match?
+		if ($this->sess_match_useragent == TRUE AND trim($session['user_agent']) != trim(substr($this->CI->input->user_agent(), 0, 50)))
+		{
+			$this->sess_destroy();
+			return FALSE;
+		}
+
+		// Is there a corresponding session in the DB?
+		if ($this->sess_use_database === TRUE)
+		{
+			$this->CI->db->where('session_id', $session['session_id']);
+
+			if ($this->sess_match_ip == TRUE)
+			{
+				$this->CI->db->where('ip_address', $session['ip_address']);
+			}
+
+			if ($this->sess_match_useragent == TRUE)
+			{
+				$this->CI->db->where('user_agent', $session['user_agent']);
+			}
+
+			$query = $this->CI->db->get($this->sess_table_name);
+
+			// No result?  Kill it!
+			if ($query->num_rows() == 0)
+			{
+				$this->sess_destroy();
+				return FALSE;
+			}
+
+			// Is there custom data?  If so, add it to the main session array
+			$row = $query->row();
+			if (isset($row->user_data) AND $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
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	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
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	function sess_create()
+	{
+		$sessid = '';
+		while (strlen($sessid) < 32)
+		{
+			$sessid .= mt_rand(0, mt_getrandmax());
+		}
+
+		// To make the session ID even more secure we'll combine it with the user's IP
+		$sessid .= $this->CI->input->ip_address();
+
+		$this->userdata = array(
+							'session_id' 	=> md5(uniqid($sessid, TRUE)),
+							'ip_address' 	=> $this->CI->input->ip_address(),
+							'user_agent' 	=> substr($this->CI->input->user_agent(), 0, 50),
+							'last_activity'	=> $this->now
+							);
+
+
+		// Save the data to the DB if needed
+		if ($this->sess_use_database === TRUE)
+		{
+			$this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $this->userdata));
+		}
+
+		// Write the cookie
+		$this->_set_cookie();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Update an existing session
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	function sess_update()
+	{
+		// We only update the session every five minutes by default
+		if (($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
+		{
+			return;
+		}
+
+		// Save the old session id so we know which record to
+		// update in the database if we need it
+		$old_sessid = $this->userdata['session_id'];
+		$new_sessid = '';
+		while (strlen($new_sessid) < 32)
+		{
+			$new_sessid .= mt_rand(0, mt_getrandmax());
+		}
+
+		// To make the session ID even more secure we'll combine it with the user's IP
+		$new_sessid .= $this->CI->input->ip_address();
+
+		// Turn it into a hash
+		$new_sessid = md5(uniqid($new_sessid, TRUE));
+
+		// Update the session data in the session data array
+		$this->userdata['session_id'] = $new_sessid;
+		$this->userdata['last_activity'] = $this->now;
+
+		// _set_cookie() will handle this for us if we aren't using database sessions
+		// by pushing all userdata to the cookie.
+		$cookie_data = NULL;
+
+		// Update the session ID and last_activity field in the DB if needed
+		if ($this->sess_use_database === TRUE)
+		{
+			// set cookie explicitly to only have our session data
+			$cookie_data = array();
+			foreach (array('session_id','ip_address','user_agent','last_activity') as $val)
+			{
+				$cookie_data[$val] = $this->userdata[$val];
+			}
+
+			$this->CI->db->query($this->CI->db->update_string($this->sess_table_name, array('last_activity' => $this->now, 'session_id' => $new_sessid), array('session_id' => $old_sessid)));
+		}
+
+		// Write the cookie
+		$this->_set_cookie($cookie_data);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Destroy the current session
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	function sess_destroy()
+	{
+		// Kill the session DB row
+		if ($this->sess_use_database === TRUE AND isset($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,
+					$this->cookie_domain,
+					0
+				);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Fetch a specific item from the session array
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function userdata($item)
+	{
+		return ( ! isset($this->userdata[$item])) ? FALSE : $this->userdata[$item];
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Fetch all session data
+	 *
+	 * @access	public
+	 * @return	mixed
+	 */
+	function all_userdata()
+	{
+		return ( ! isset($this->userdata)) ? FALSE : $this->userdata;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Add or change data in the "userdata" array
+	 *
+	 * @access	public
+	 * @param	mixed
+	 * @param	string
+	 * @return	void
+	 */
+	function set_userdata($newdata = array(), $newval = '')
+	{
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => $newval);
+		}
+
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$this->userdata[$key] = $val;
+			}
+		}
+
+		$this->sess_write();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Delete a session variable from the "userdata" array
+	 *
+	 * @access	array
+	 * @return	void
+	 */
+	function unset_userdata($newdata = array())
+	{
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => '');
+		}
+
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				unset($this->userdata[$key]);
+			}
+		}
+
+		$this->sess_write();
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Add or change flashdata, only available
+	 * until the next request
+	 *
+	 * @access	public
+	 * @param	mixed
+	 * @param	string
+	 * @return	void
+	 */
+	function set_flashdata($newdata = array(), $newval = '')
+	{
+		if (is_string($newdata))
+		{
+			$newdata = array($newdata => $newval);
+		}
+
+		if (count($newdata) > 0)
+		{
+			foreach ($newdata as $key => $val)
+			{
+				$flashdata_key = $this->flashdata_key.':new:'.$key;
+				$this->set_userdata($flashdata_key, $val);
+			}
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Keeps existing flashdata available to next request.
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	void
+	 */
+	function keep_flashdata($key)
+	{
+		// 'old' flashdata gets removed.  Here we mark all
+		// flashdata as 'new' to preserve it from _flashdata_sweep()
+		// Note the function will return FALSE if the $key
+		// provided cannot be found
+		$old_flashdata_key = $this->flashdata_key.':old:'.$key;
+		$value = $this->userdata($old_flashdata_key);
+
+		$new_flashdata_key = $this->flashdata_key.':new:'.$key;
+		$this->set_userdata($new_flashdata_key, $value);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Fetch a specific flashdata item from the session array
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function flashdata($key)
+	{
+		$flashdata_key = $this->flashdata_key.':old:'.$key;
+		return $this->userdata($flashdata_key);
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Identifies flashdata as 'old' for removal
+	 * when _flashdata_sweep() runs.
+	 *
+	 * @access	private
+	 * @return	void
+	 */
+	function _flashdata_mark()
+	{
+		$userdata = $this->all_userdata();
+		foreach ($userdata as $name => $value)
+		{
+			$parts = explode(':new:', $name);
+			if (is_array($parts) && count($parts) === 2)
+			{
+				$new_name = $this->flashdata_key.':old:'.$parts[1];
+				$this->set_userdata($new_name, $value);
+				$this->unset_userdata($name);
+			}
+		}
+	}
+
+	// ------------------------------------------------------------------------
+
+	/**
+	 * Removes all flashdata marked as 'old'
+	 *
+	 * @access	private
+	 * @return	void
+	 */
+
+	function _flashdata_sweep()
+	{
+		$userdata = $this->all_userdata();
+		foreach ($userdata as $key => $value)
+		{
+			if (strpos($key, ':old:'))
+			{
+				$this->unset_userdata($key);
+			}
+		}
+
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Get the "now" time
+	 *
+	 * @access	private
+	 * @return	string
+	 */
+	function _get_time()
+	{
+		if (strtolower($this->time_reference) == 'gmt')
+		{
+			$now = time();
+			$time = mktime(gmdate("H", $now), gmdate("i", $now), gmdate("s", $now), gmdate("m", $now), gmdate("d", $now), gmdate("Y", $now));
+		}
+		else
+		{
+			$time = time();
+		}
+
+		return $time;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Write the session cookie
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	function _set_cookie($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);
+		}
+
+		// Set the cookie
+		setcookie(
+					$this->sess_cookie_name,
+					$cookie_data,
+					$this->sess_expiration + time(),
+					$this->cookie_path,
+					$this->cookie_domain,
+					0
+				);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Serialize an array
+	 *
+	 * This function first converts any slashes found in the array to a temporary
+	 * marker, so when it gets unserialized the slashes will be preserved
+	 *
+	 * @access	private
+	 * @param	array
+	 * @return	string
+	 */
+	function _serialize($data)
+	{
+		if (is_array($data))
+		{
+			foreach ($data as $key => $val)
+			{
+				$data[$key] = str_replace('\\', '{{slash}}', $val);
+			}
+		}
+		else
+		{
+			$data = str_replace('\\', '{{slash}}', $data);
+		}
+
+		return serialize($data);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Unserialize
+	 *
+	 * This function unserializes a data string, then converts any
+	 * temporary slash markers back to actual slashes
+	 *
+	 * @access	private
+	 * @param	array
+	 * @return	string
+	 */
+	function _unserialize($data)
+	{
+		$data = @unserialize(strip_slashes($data));
+
+		if (is_array($data))
+		{
+			foreach ($data as $key => $val)
+			{
+				$data[$key] = str_replace('{{slash}}', '\\', $val);
+			}
+
+			return $data;
+		}
+
+		return str_replace('{{slash}}', '\\', $data);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Garbage collection
+	 *
+	 * This deletes expired session rows from database
+	 * if the probability percentage is met
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	function _sess_gc()
+	{
+		if ($this->sess_use_database != TRUE)
+		{
+			return;
+		}
+
+		srand(time());
+		if ((rand() % 100) < $this->gc_probability)
+		{
+			$expire = $this->now - $this->sess_expiration;
+
+			$this->CI->db->where("last_activity < {$expire}");
+			$this->CI->db->delete($this->sess_table_name);
+
+			log_message('debug', 'Session garbage collection performed.');
+		}
+	}
+
+
+}
+// END Session Class
+
+/* End of file Session.php */
+/* Location: ./system/libraries/Session.php */
\ No newline at end of file