php 加解密函数
- <?php
- //加解密函数
- $encode = authcode('我要加密','ENCODE','34577');
- $decode = authcode($encode,'DECODE','34577');
- echo $encode."
- ";
- echo $decode;
- //$auth_key = 34577 ; //密钥
- function authcode($string, $operation, $key = '')
- {
- $key = md5($key ? $key : $GLOBALS['auth_key']);
- $key_length = strlen($key);
- $string = $operation == 'DECODE' ? base64_decode($string) : substr(md5($string.$key), 0, 8).$string;
- $string_length = strlen($string);
- $rndkey = $box = array();
- $result = '';
- for($i = 0; $i <= 255; $i++) {
- $rndkey[$i] = ord($key[$i % $key_length]);
- $box[$i] = $i;
- }
- for($j = $i = 0; $i < 256; $i++) {
- $j = ($j + $box[$i] + $rndkey[$i]) % 256;
- $tmp = $box[$i];
- $box[$i] = $box[$j];
- $box[$j] = $tmp;
- }
- for($a = $j = $i = 0; $i < $string_length; $i++) {
- $a = ($a + 1) % 256;
- $j = ($j + $box[$a]) % 256;
- $tmp = $box[$a];
- $box[$a] = $box[$j];
- $box[$j] = $tmp;
- $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
- }
- if($operation == 'DECODE') {
- if(substr($result, 0, 8) == substr(md5(substr($result, 8).$key), 0, 8)) {
- return substr($result, 8);
- } else {
- return '';
- }
- } else {
- return str_replace('=', '', base64_encode($result));
- }
- }
- ?>
