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<?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>
// +----------------------------------------------------------------------
// $Id: Base64.class.php 2504 2011-12-28 07:35:29Z liu21st $
/**
+------------------------------------------------------------------------------
* Base64 加密实现类
+------------------------------------------------------------------------------
* @category ORG
* @package ORG
* @subpackage Crypt
* @author liu21st <liu21st@gmail.com>
* @version $Id: Base64.class.php 2504 2011-12-28 07:35:29Z liu21st $
+------------------------------------------------------------------------------
*/
class Base64 {
/**
+----------------------------------------------------------
* 加密字符串
+----------------------------------------------------------
* @access static
+----------------------------------------------------------
* @param string $str 字符串
* @param string $key 加密key
+----------------------------------------------------------
* @return string
+----------------------------------------------------------
* @throws ThinkExecption
+----------------------------------------------------------
*/
public static function encrypt($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 $key 加密key
+----------------------------------------------------------
* @return string
+----------------------------------------------------------
* @throws ThinkExecption
+----------------------------------------------------------
*/
public static function decrypt($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);
}
}
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