Initial Import

1 files changed, 378 insertions, 0 deletions

diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
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+<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * Code Igniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package		CodeIgniter
+ * @author		Rick Ellis
+ * @copyright	Copyright (c) 2006, pMachine, Inc.
+ * @license		http://www.codeignitor.com/user_guide/license.html 
+ * @link		http://www.codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+ 
+// ------------------------------------------------------------------------
+
+/**
+ * Code Igniter Encryption Class
+ *
+ * Provides two-way keyed encoding using XOR Hashing and Mcrypt
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Libraries
+ * @author		Rick Ellis
+ * @link		http://www.codeigniter.com/user_guide/libraries/encryption.html
+ */
+class CI_Encrypt {
+	var $_hash_type	= 'sha1';
+	var $_mcrypt_exists = FALSE;
+	var $_mcrypt_cipher;
+	var $_mcrypt_mode;
+	
+	/**
+	 * Constructor
+	 *
+	 * Simply determines whether the mcrypt library exists.
+	 *
+	 */
+	function CI_Encrypt()
+	{
+		$this->_mcrypt_exists = ( ! function_exists('mcrypt_encrypt')) ? FALSE : TRUE;
+		log_message('debug', "Encrypt Class Initialized");
+	}
+  	// END CI_Encrypt()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Fetch the encryption key
+	 *
+	 * Returns it as MD5 in order to have an exact-length 128 bit key.
+	 * Mcrypt is sensitive to keys that are not the correct length
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function get_key($key = '')
+	{
+		if ($key == '')
+		{	
+			$obj =& get_instance();
+			$key = $obj->config->item('encryption_key');
+
+			if ($key === FALSE)
+			{
+				show_error('In order to use the encryption class requires that you set an encryption key in your config file.');
+			}
+		}
+		
+		return md5($key);
+	}
+  	// END get_key()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Encode
+	 *
+	 * Encodes the message string using bitwise XOR encoding.  
+	 * The key is combined with a random hash, and then it 
+	 * too gets converted using XOR. The whole thing is then run 
+	 * through mcrypt (if supported) using the randomized key.  
+	 * The end result is a double-encrypted message string 
+	 * that is randomized with each call to this function, 
+	 * even if the supplied message and key are the same.
+	 *
+	 * @access	public
+	 * @param	string	the string to encode
+	 * @param	string	the key
+	 * @return	string
+	 */
+	function encode($string, $key = '')
+	{
+		$key = $this->get_key($key);
+		$enc = $this->_xor_encode($string, $key);
+		
+		if ($this->_mcrypt_exists === TRUE)
+		{
+			$enc = $this->mcrypt_encode($enc, $key);
+		}
+		return base64_encode($enc);		
+	}
+  	// END encode()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Decode
+	 *
+	 * Reverses the above process
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function decode($string, $key = '')
+	{
+		$key = $this->get_key($key);
+		$dec = base64_decode($string);
+		
+		 if ($dec === FALSE)
+		 {
+		 	return FALSE;
+		 }
+		
+		if ($this->_mcrypt_exists === TRUE)
+		{
+			$dec = $this->mcrypt_decode($dec, $key);
+		}
+		
+		return $this->_xor_decode($dec, $key);
+	}
+  	// END decode()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * XOR Encode
+	 *
+	 * Takes a plain-text string and key as input and generates an
+	 * encoded bit-string using XOR
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */	
+	function _xor_encode($string, $key)
+	{
+		$rand = '';
+		while (strlen($rand) < 32) 
+		{    
+			$rand .= mt_rand(0, mt_getrandmax());
+		}
+	
+		$rand = $this->hash($rand);
+		
+		$enc = '';
+		for ($i = 0; $i < strlen($string); $i++)
+		{			
+			$enc .= substr($rand, ($i % strlen($rand)), 1).(substr($rand, ($i % strlen($rand)), 1) ^ substr($string, $i, 1));
+		}
+				
+		return $this->_xor_merge($enc, $key);
+	}
+  	// END _xor_encode()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * XOR Decode
+	 *
+	 * Takes an encoded string and key as input and generates the 
+	 * plain-text original message
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */	
+	function _xor_decode($string, $key)
+	{
+		$string = $this->_xor_merge($string, $key);
+		
+		$dec = '';
+		for ($i = 0; $i < strlen($string); $i++)
+		{
+			$dec .= (substr($string, $i++, 1) ^ substr($string, $i, 1));
+		}
+	
+		return $dec;
+	}
+  	// END _xor_decode()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * XOR key + string Combiner
+	 *
+	 * Takes a string and key as input and computes the difference using XOR
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */	
+	function _xor_merge($string, $key)
+	{
+		$hash = $this->hash($key);
+		$str = '';
+		for ($i = 0; $i < strlen($string); $i++)
+		{
+			$str .= substr($string, $i, 1) ^ substr($hash, ($i % strlen($hash)), 1);
+		}
+		
+		return $str;
+	}
+  	// END _xor_merge()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Encrypt using Mcrypt
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function mcrypt_encode($data, $key) 
+	{	
+		$this->_get_mcrypt();
+		$init_size = mcrypt_get_iv_size($this->_mcrypt_cipher, $this->_mcrypt_mode);
+		$init_vect = mcrypt_create_iv($init_size, MCRYPT_RAND);
+		return mcrypt_encrypt($this->_mcrypt_cipher, $key, $data, $this->_mcrypt_mode, $init_vect);
+	}
+  	// END mcrypt_encode()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Decrypt using Mcrypt
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */	
+	function mcrypt_decode($data, $key) 
+	{
+		$this->_get_mcrypt();
+		$init_size = mcrypt_get_iv_size($this->_mcrypt_cipher, $this->_mcrypt_mode);
+		$init_vect = mcrypt_create_iv($init_size, MCRYPT_RAND);
+		return rtrim(mcrypt_decrypt($this->_mcrypt_cipher, $key, $data, $this->_mcrypt_mode, $init_vect), "\0");
+	}
+  	// END mcrypt_decode()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set the Mcrypt Cypher
+	 *
+	 * @access	public
+	 * @param	constant
+	 * @return	string
+	 */
+	function set_cypher($cypher)
+	{
+		$this->_mcrypt_cipher = $cypher;
+	}
+  	// END set_cypher()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set the Mcrypt Mode
+	 *
+	 * @access	public
+	 * @param	constant
+	 * @return	string
+	 */
+	function set_mode($mode)
+	{
+		$this->_mcrypt_mode = $mode;
+	}
+  	// END set_mode()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Get Mcrypt value
+	 *
+	 * @access	private
+	 * @param	string
+	 * @return	string
+	 */	
+	function _get_mcrypt()
+	{
+		if ($this->_mcrypt_cipher == '') 
+		{
+			$this->_mcrypt_cipher = MCRYPT_RIJNDAEL_256;
+		}
+		if ($this->_mcrypt_mode == '') 
+		{
+			$this->_mcrypt_mode = MCRYPT_MODE_ECB;
+		}
+	}
+  	// END _get_mcrypt()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set the Hash type
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */		
+	function set_hash($type = 'sha1')
+	{
+		$this->_hash_type = ($type != 'sha1' OR $type != 'md5') ? 'sha1' : $type;
+	}
+  	// END set_hash()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Hash encode a string
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */		
+	function hash($str)
+	{
+		return ($this->_hash_type == 'sha1') ? $this->sha1($str) : md5($str);
+	}
+  	// END hash()
+  	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Generate an SHA1 Hash
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */	
+	function sha1($str)
+	{
+		if ( ! function_exists('sha1'))
+		{
+			if ( ! function_exists('mhash'))
+			{	
+				require_once(BASEPATH.'libraries/Sha1'.EXT);
+				$SH = new CI_SHA;
+				return $SH->generate($str);            
+			}
+			else
+			{
+				return bin2hex(mhash(MHASH_SHA1, $str));
+			}
+		}
+		else
+		{
+			return sha1($str);
+		}	
+	}  
+	// END sha1()
+	
+}
+
+// END CI_Encrypt class
+?>
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