<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2009 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
/**
* Base64 加密实现类
* @category ORG
* @package ORG
* @subpackage Crypt
* @author liu21st <liu21st@gmail.com>
*/
class Base64 {
/**
* 加密字符串
* @access static
* @param string $str 字符串
* @param string $key 加密key
* @return string
*/
public static function encrypt($data,$key) {
$key = md5($key);
$data = base64_encode($data);
$x=0;
$len = strlen($data);
$l = strlen($key);
for ($i=0;$i< $len;$i++) {
if ($x== $l) $x=0;
$char .=substr($key,$x,1);
$x++;
}
for ($i=0;$i< $len;$i++) {
$str .=chr(ord(substr($data,$i,1))+(ord(substr($char,$i,1)))%256);
}
return $str;
}
/**
* 解密字符串
* @access static
* @param string $str 字符串
* @param string $key 加密key
* @return string
*/
public static function decrypt($data,$key) {
$key = md5($key);
$x=0;
$len = strlen($data);
$l = strlen($key);
for ($i=0;$i< $len;$i++) {
if ($x== $l) $x=0;
$char .=substr($key,$x,1);
$x++;
}
for ($i=0;$i< $len;$i++) {
if (ord(substr($data,$i,1))<ord(substr($char,$i,1))) {
$str .=chr((ord(substr($data,$i,1))+256)-ord(substr($char,$i,1)));
}else{
$str .=chr(ord(substr($data,$i,1))-ord(substr($char,$i,1)));
}
}
return base64_decode($str);
}
}