Initial commit

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

1 files changed, 484 insertions, 0 deletions

diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
new file mode 100644
index 000000000..95c758fb4
--- /dev/null
+++ b/system/libraries/Encrypt.php
@@ -0,0 +1,484 @@
+<?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
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * CodeIgniter Encryption Class
+ *
+ * Provides two-way keyed encoding using XOR Hashing and Mcrypt
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Libraries
+ * @author		ExpressionEngine Dev Team
+ * @link		http://codeigniter.com/user_guide/libraries/encryption.html
+ */
+class CI_Encrypt {
+
+	var $CI;
+	var $encryption_key	= '';
+	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->CI =& get_instance();
+		$this->_mcrypt_exists = ( ! function_exists('mcrypt_encrypt')) ? FALSE : TRUE;
+		log_message('debug', "Encrypt Class Initialized");
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Fetch the encryption key
+	 *
+	 * Returns it as MD5 in order to have an exact-length 128 bit key.
+	 * Mcrypt is sensitive to keys that are not the correct length
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function get_key($key = '')
+	{
+		if ($key == '')
+		{
+			if ($this->encryption_key != '')
+			{
+				return $this->encryption_key;
+			}
+
+			$CI =& get_instance();
+			$key = $CI->config->item('encryption_key');
+
+			if ($key === FALSE)
+			{
+				show_error('In order to use the encryption class requires that you set an encryption key in your config file.');
+			}
+		}
+
+		return md5($key);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set the encryption key
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	void
+	 */
+	function set_key($key = '')
+	{
+		$this->encryption_key = $key;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Encode
+	 *
+	 * Encodes the message string using bitwise XOR encoding.
+	 * The key is combined with a random hash, and then it
+	 * too gets converted using XOR. The whole thing is then run
+	 * through mcrypt (if supported) using the randomized key.
+	 * The end result is a double-encrypted message string
+	 * that is randomized with each call to this function,
+	 * even if the supplied message and key are the same.
+	 *
+	 * @access	public
+	 * @param	string	the string to encode
+	 * @param	string	the key
+	 * @return	string
+	 */
+	function encode($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);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Decode
+	 *
+	 * Reverses the above process
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function decode($string, $key = '')
+	{
+		$key = $this->get_key($key);
+		
+		if (preg_match('/[^a-zA-Z0-9\/\+=]/', $string))
+		{
+			return FALSE;
+		}
+
+		$dec = base64_decode($string);
+
+		if ($this->_mcrypt_exists === TRUE)
+		{
+			if (($dec = $this->mcrypt_decode($dec, $key)) === FALSE)
+			{
+				return FALSE;
+			}
+		}
+
+		return $this->_xor_decode($dec, $key);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * XOR Encode
+	 *
+	 * Takes a plain-text string and key as input and generates an
+	 * encoded bit-string using XOR
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function _xor_encode($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, $key);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * XOR Decode
+	 *
+	 * Takes an encoded string and key as input and generates the
+	 * plain-text original message
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function _xor_decode($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 $dec;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * XOR key + string Combiner
+	 *
+	 * Takes a string and key as input and computes the difference using XOR
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function _xor_merge($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 $str;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Encrypt using Mcrypt
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function mcrypt_encode($data, $key)
+	{
+		$init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
+		$init_vect = mcrypt_create_iv($init_size, MCRYPT_RAND);
+		return $this->_add_cipher_noise($init_vect.mcrypt_encrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), $key);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Decrypt using Mcrypt
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function mcrypt_decode($data, $key)
+	{
+		$data = $this->_remove_cipher_noise($data, $key);
+		$init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
+
+		if ($init_size > strlen($data))
+		{
+			return FALSE;
+		}
+
+		$init_vect = substr($data, 0, $init_size);
+		$data = substr($data, $init_size);
+		return rtrim(mcrypt_decrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), "\0");
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Adds permuted noise to the IV + encrypted data to protect
+	 * against Man-in-the-middle attacks on CBC mode ciphers
+	 * http://www.ciphersbyritter.com/GLOSSARY.HTM#IV
+	 *
+	 * Function description
+	 *
+	 * @access	private
+	 * @param	string
+	 * @param	string
+	 * @return	string
+	 */
+	function _add_cipher_noise($data, $key)
+	{
+		$keyhash = $this->hash($key);
+		$keylen = strlen($keyhash);
+		$str = '';
+
+		for ($i = 0, $j = 0, $len = strlen($data); $i < $len; ++$i, ++$j)
+		{
+			if ($j >= $keylen)
+			{
+				$j = 0;
+			}
+
+			$str .= chr((ord($data[$i]) + ord($keyhash[$j])) % 256);
+		}
+
+		return $str;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Removes permuted noise from the IV + encrypted data, reversing
+	 * _add_cipher_noise()
+	 *
+	 * Function description
+	 *
+	 * @access	public
+	 * @param	type
+	 * @return	type
+	 */
+	function _remove_cipher_noise($data, $key)
+	{
+		$keyhash = $this->hash($key);
+		$keylen = strlen($keyhash);
+		$str = '';
+
+		for ($i = 0, $j = 0, $len = strlen($data); $i < $len; ++$i, ++$j)
+		{
+			if ($j >= $keylen)
+			{
+				$j = 0;
+			}
+
+			$temp = ord($data[$i]) - ord($keyhash[$j]);
+
+			if ($temp < 0)
+			{
+				$temp = $temp + 256;
+			}
+			
+			$str .= chr($temp);
+		}
+
+		return $str;
+	}
+
+	// --------------------------------------------------------------------
+	
+	/**
+	 * Set the Mcrypt Cipher
+	 *
+	 * @access	public
+	 * @param	constant
+	 * @return	string
+	 */
+	function set_cipher($cipher)
+	{
+		$this->_mcrypt_cipher = $cipher;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set the Mcrypt Mode
+	 *
+	 * @access	public
+	 * @param	constant
+	 * @return	string
+	 */
+	function set_mode($mode)
+	{
+		$this->_mcrypt_mode = $mode;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Get Mcrypt cipher Value
+	 *
+	 * @access	private
+	 * @return	string
+	 */
+	function _get_cipher()
+	{
+		if ($this->_mcrypt_cipher == '')
+		{
+			$this->_mcrypt_cipher = MCRYPT_RIJNDAEL_256;
+		}
+
+		return $this->_mcrypt_cipher;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Get Mcrypt Mode Value
+	 *
+	 * @access	private
+	 * @return	string
+	 */
+	function _get_mode()
+	{
+		if ($this->_mcrypt_mode == '')
+		{
+			$this->_mcrypt_mode = MCRYPT_MODE_ECB;
+		}
+		
+		return $this->_mcrypt_mode;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set the Hash type
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function set_hash($type = 'sha1')
+	{
+		$this->_hash_type = ($type != 'sha1' AND $type != 'md5') ? 'sha1' : $type;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Hash encode a string
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */	
+	function hash($str)
+	{
+		return ($this->_hash_type == 'sha1') ? $this->sha1($str) : md5($str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Generate an SHA1 Hash
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function sha1($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 CI_Encrypt class
+
+/* End of file Encrypt.php */
+/* Location: ./system/libraries/Encrypt.php */
\ No newline at end of file