cmv Thu Jan 11 14:51:20 2001 EDT
Added files:
/php4/pear/Crypt CBC.php
Log:
Class that emulates Perl's Crypt::CBC module
PR:
Submitted by:
Reviewed by:
Obtained from:
Index: php4/pear/Crypt/CBC.php
+++ php4/pear/Crypt/CBC.php
<?php
/* vim: set ts=4 sw=4: */
// +----------------------------------------------------------------------+
// | PHP version 4.0 |
// +----------------------------------------------------------------------+
// | Copyright (c) 2001 The PHP Group |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.0 of the PHP license, |
// | that is bundled with this package in the file LICENSE, and is |
// | available at through the world-wide-web at |
// | http://www.php.net/license/2_02.txt. |
// | If you did not receive a copy of the PHP license and are unable to |
// | obtain it through the world-wide-web, please send a note to |
// | [EMAIL PROTECTED] so we can mail you a copy immediately. |
// +----------------------------------------------------------------------+
// | Authors: Colin Viebrock <[EMAIL PROTECTED]> |
// +----------------------------------------------------------------------+
//
/**
* Class to emulate Perl's Crypt::CBC module
*
* Blowfish support is not completely working, mainly because of a bug
* discovered in libmcrypt (version 2.4.8 and earlier). If you are running
* a later version of libmcrypt > 2.4.8, you can do Blowfish encryption
* that is compatable with Perl. However, check the libmcrypt documenation
* as to whether you should use 'BLOWFISH' or 'BLOWFISH-COMPAT' when
* specifying the cipher.
*
* If you are using libmcrypt <= 2.4.8, Blowfish encryption will work,
* but your data will not be readable by Perl scripts. It will work
* "internally" .. i.e. this class will be able to encode/decode the data.
*
* NOTE: the cipher names in this class may change depending on how
* the author of libcrypt decides to name things internally.
*
* This code was based on work by Mike Glover <[EMAIL PROTECTED]>
*
*
* @version $Id: CBC.php,v 1.1 2001/01/11 22:51:20 cmv Exp $
* @author Colin Viebrock <[EMAIL PROTECTED]>
*
*/
require_once 'PEAR.php';
if (function_exists('mcrypt_module_open')) {
define('CRYPT_CBC_USING_24x', 1);
} else {
define('CRYPT_CBC_USING_24x', 0);
}
class CBC extends PEAR {
var $known_ciphers = array (
'DES' => MCRYPT_DES,
'BLOWFISH' => MCRYPT_BLOWFISH,
'BLOWFISH-COMPAT' => MCRYPT_BLOWFISH_COMPAT,
);
var $cipher; # used cipher
var $TD; # crypt resource, for 2.4.x
var $blocksize; # blocksize of cipher
var $keysize; # keysize of cipher
var $keyhash; # mangled key
var $error;
var $rand_source = MCRYPT_RAND; # or MCRYPT_DEV_URANDOM or MCRYPT_DEV_RANDOM
var $header_spec = 'RandomIV'; # header
var $_last_clear; # debugging
var $_last_crypt; # debugging
/**
* Constructor
*
* @param $key encryption key
* @param $cipher which algorithm to use, defaults to DES
*
* @return $return either a PEAR error or true
*
* @access public
*
*/
function CBC ($key, $cipher='DES')
{
if (!extension_loaded('mcrypt')) {
$this->error = new Crypt_CBC_Error('mcrypt module is not compiled into
PHP: compile PHP using --with-mcrypt.');
return $this->error;
}
/* seed randomizer */
srand ((double)microtime()*1000000);
/* initialize */
$this->header_spec = 'RandomIV';
/* check for key */
if (!$key) {
$this->error = new Crypt_CBC_Error('No key specified');
return $this->error;
}
/* check for cipher */
$cipher = strtoupper($cipher);
if (!isset($this->known_ciphers[$cipher])) {
$this->error = new Crypt_CBC_Error('Unknown cipher: ' . $cipher);
return $this->error;
}
$this->cipher = $this->known_ciphers[$cipher];
/* initialize cipher */
if (USING_24x) {
$this->blocksize = mcrypt_get_block_size($this->cipher,'cbc');
$this->keysize = mcrypt_get_key_size($this->cipher,'cbc');
$this->TD = mcrypt_module_open ($this->cipher, '', 'ecb', '');
} else {
$this->blocksize = mcrypt_get_block_size('cbc');
$this->keysize = mcrypt_get_key_size('cbc');
$this->TD = false;
}
/* mangle key with MD5 */
$this->keyhash = $this->_md5perl($key);
while( strlen($this->keyhash) < $this->keysize ) {
$this->keyhash .= $this->_md5perl($this->keyhash);
}
$this->key = substr($this->keyhash, 0, $this->keysize);
return true;
}
/**
* Encryption method
*
* @param $clear plaintext
*
* @return $crypt encrypted text, or PEAR error
*
* @access public
*
*/
function encrypt($clear)
{
$this->last_clear = $clear;
/* new IV for each message */
$iv = mcrypt_create_iv($this->blocksize, $this->rand_source);
/* create the message header */
$crypt = $this->header_spec . $iv;
/* pad the cleartext */
$padsize = $this->blocksize - (strlen($clear) % $this->blocksize);
$clear .= str_repeat(pack ('C*', $padsize), $padsize);
/* do the encryption */
$start = 0;
while ( $block = substr($clear, $start, $this->blocksize) ) {
$start += $this->blocksize;
if (USING_24x) {
mcrypt_generic_init($this->TD, $this->key, $iv);
$cblock = mcrypt_generic($this->TD, $iv^$block );
} else {
$cblock = mcrypt_ECB($this->cipher, $this->key, $iv^$block,
MCRYPT_ENCRYPT );
}
$iv = $cblock;
$crypt .= $cblock;
}
$this->last_crypt = $crypt;
return $crypt;
}
/**
* Decryption method
*
* @param $crypt encrypted text
*
* @return $clear plaintext, or PEAR error
*
* @access public
*
*/
function decrypt($crypt) {
$this->last_crypt = $crypt;
/* get the IV from the message header */
$iv_offset = strlen($this->header_spec);
$header = substr($crypt, 0, $iv_offset);
$iv = substr ($crypt, $iv_offset, $this->blocksize);
if ( $header != $this->header_spec ) {
$this->error = new Crypt_CBC_Error('No initialization vector');
return $this->error;
}
$crypt = substr($crypt, $iv_offset+$this->blocksize);
/* decrypt the message */
while ( $cblock = substr($crypt, $start, $this->blocksize) ) {
$start += $this->blocksize;
if (USING_24x) {
mcrypt_generic_init($this->TD, $this->key, $iv);
$block = $iv ^ mdecrypt_generic($this->TD, $cblock);
} else {
$block = $iv ^ mcrypt_ECB($this->cipher, $this->key, $cblock,
MCRYPT_DECRYPT );
}
$iv = $cblock;
$clear .= $block;
}
/* remove the padding from the end of the cleartext */
$padsize = ord(substr($clear, -1));
$clear = substr($clear, 0, -$padsize);
$this->last_clear = $clear;
return $clear;
}
/**
* Emulate Perl's MD5 function, which returns binary data
*
* @param $string string to MD5
*
* @return $hash binary hash
*
* @access private
*
*/
function _md5perl($string)
{
return pack('H*', md5($string));
}
}
class Crypt_CBC_Error extends PEAR_Error
{
var $classname = 'Crypt_CBC_Error';
var $error_message_prepend = 'Error in Crypt_CBC';
function Crypt_CBC_Error ($message, $code = 0, $mode = PEAR_ERROR_RETURN, $level =
E_USER_NOTICE)
{
$this->PEAR_Error ($message, $code, $mode, $level);
}
}
?>
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