<?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> // +---------------------------------------------------------------------- namespace Think\Crypt\Driver; /** * Base64 加密实现类 */ class Base64 { /** * 加密字符串 * @param string $str 字符串 * @param string $key 加密key * @param integer $expire 有效期(秒) * @return string */ public static function encrypt($data,$key,$expire=0) { $expire = sprintf('%010d', $expire ? $expire + time():0); $key = md5($key); $data = base64_encode($expire.$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 * @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))); } } $data = base64_decode($str); $expire = substr($data,0,10); if($expire > 0 && $expire < time()) { return ''; } $data = substr($data,10); return $data; } }