From b0dd10f8171945e0c1f3527dd1e9d18b043e01a7 Mon Sep 17 00:00:00 2001 From: admin Date: Fri, 25 Aug 2006 17:25:49 +0000 Subject: Initial Import --- system/libraries/Encrypt.php | 378 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 378 insertions(+) create mode 100644 system/libraries/Encrypt.php (limited to 'system/libraries/Encrypt.php') diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php new file mode 100644 index 000000000..532bfe1f1 --- /dev/null +++ b/system/libraries/Encrypt.php @@ -0,0 +1,378 @@ +_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 +?> \ No newline at end of file -- cgit v1.2.3-24-g4f1b