| <?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) 2006, 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
|
| *
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| * @package CodeIgniter
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| * @subpackage Libraries
|
| * @category Libraries
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| * @author ExpressionEngine Dev Team
|
| * @link http://codeigniter.com/user_guide/libraries/encryption.html
|
| */
|
| class CI_Encrypt {
|
|
|
| var $CI;
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| var $encryption_key = '';
|
| var $_hash_type = 'sha1';
|
| var $_mcrypt_exists = FALSE;
|
| var $_mcrypt_cipher;
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| var $_mcrypt_mode;
|
|
|
| /**
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| * Constructor
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| *
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| * Simply determines whether the mcrypt library exists.
|
| *
|
| */
|
| function CI_Encrypt()
|
| {
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| $this->CI =& get_instance();
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| $this->_mcrypt_exists = (! function_exists('mcrypt_encrypt')) ? FALSE : TRUE;
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| log_message('debug', "Encrypt Class Initialized");
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| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
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| * Fetch the encryption key
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| *
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| * Returns it as MD5 in order to have an exact-length 128 bit key.
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| * Mcrypt is sensitive to keys that are not the correct length
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| *
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| * @access public
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| * @param string
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| * @return string
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| */
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| function get_key($key = '')
|
| {
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| if ($key == '')
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| {
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| if ($this->encryption_key != '')
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| {
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| return $this->encryption_key;
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| }
|
|
|
| $CI =& get_instance();
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| $key = $CI->config->item('encryption_key');
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|
|
| if ($key === FALSE)
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| {
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| show_error('In order to use the encryption class requires that you set an encryption key in your config file.');
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| }
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| }
|
|
|
| return md5($key);
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| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
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| * Set the encryption key
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| *
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| * @access public
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| * @param string
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| * @return void
|
| */
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| function set_key($key = '')
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| {
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| $this->encryption_key = $key;
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| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
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| * Encode
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| *
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| * Encodes the message string using bitwise XOR encoding.
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| * The key is combined with a random hash, and then it
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| * too gets converted using XOR. The whole thing is then run
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| * through mcrypt (if supported) using the randomized key.
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| * The end result is a double-encrypted message string
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| * that is randomized with each call to this function,
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| * even if the supplied message and key are the same.
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| *
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| * @access public
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| * @param string the string to encode
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| * @param string the key
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| * @return string
|
| */
|
| function encode($string, $key = '')
|
| {
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| $key = $this->get_key($key);
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| $enc = $this->_xor_encode($string, $key);
|
|
|
| if ($this->_mcrypt_exists === TRUE)
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| {
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| $enc = $this->mcrypt_encode($enc, $key);
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| }
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| return base64_encode($enc);
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| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
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| * Decode
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| *
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| * Reverses the above process
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| *
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| * @access public
|
| * @param string
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| * @param string
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| * @return string
|
| */
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| function decode($string, $key = '')
|
| {
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| $key = $this->get_key($key);
|
|
|
| $this->CI->load->library('validation');
|
|
|
| if ($this->CI->validation->valid_base64($string) === FALSE)
|
| {
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| return FALSE;
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| }
|
|
|
| $dec = base64_decode($string);
|
|
|
| if ($this->_mcrypt_exists === TRUE)
|
| {
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| if (($dec = $this->mcrypt_decode($dec, $key)) === FALSE)
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| {
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| return FALSE;
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| }
|
| }
|
|
|
| return $this->_xor_decode($dec, $key);
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| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * XOR Encode
|
| *
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| * Takes a plain-text string and key as input and generates an
|
| * encoded bit-string using XOR
|
| *
|
| * @access private
|
| * @param string
|
| * @param string
|
| * @return string
|
| */
|
| function _xor_encode($string, $key)
|
| {
|
| $rand = '';
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| while (strlen($rand) < 32)
|
| {
|
| $rand .= mt_rand(0, mt_getrandmax());
|
| }
|
|
|
| $rand = $this->hash($rand);
|
|
|
| $enc = '';
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| for ($i = 0; $i < strlen($string); $i++)
|
| {
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| $enc .= substr($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);
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| 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)
|
| {
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| $data = $this->_remove_cipher_noise($data, $key);
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| $init_size = mcrypt_get_iv_size($this->_get_cipher(), $this->_get_mode());
|
|
|
| if ($init_size > strlen($data))
|
| {
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| return FALSE;
|
| }
|
|
|
| $init_vect = substr($data, 0, $init_size);
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| $data = substr($data, $init_size);
|
| return rtrim(mcrypt_decrypt($this->_get_cipher(), $key, $data, $this->_get_mode(), $init_vect), "\0");
|
| }
|
|
|
| // --------------------------------------------------------------------
|
|
|
| /**
|
| * Adds permuted noise to the IV + encrypted data to protect
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| * against Man-in-the-middle attacks on CBC mode ciphers
|
| * http://www.ciphersbyritter.com/GLOSSARY.HTM#IV
|
| *
|
| * Function description
|
| *
|
| * @access private
|
| * @param string
|
| * @param string
|
| * @return string
|
| */
|
| function _add_cipher_noise($data, $key)
|
| {
|
| $keyhash = $this->hash($key);
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| $keylen = strlen($keyhash);
|
| $str = '';
|
|
|
| for ($i = 0, $j = 0, $len = strlen($data); $i < $len; ++$i, ++$j)
|
| {
|
| if ($j >= $keylen)
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| {
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| $j = 0;
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| }
|
|
|
| $str .= chr((ord($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 */ |