PHP_加密解密字符串.php

<?php//加解密字符串函数，可以加密中文/*//加密echo $encode = authcode(‘爱迪生‘, ‘ENCODE‘, ‘3‘); //DvAHOdGFqa8xK4CDLnbr2mE//解密echo $decode = authcode($encode, ‘DECODE‘, ‘3‘); //爱迪生//密钥$auth_key = 34577;参数：$string字符串，$operation加密还是解密，$key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)); }}?>