1 /********************************************************************* 2 函数名称:encrypt 3 函数作用:加密解密字符串 4 使用方法: 5 加密 :encrypt('str','E','nowamagic'); 6 解密 :encrypt('被加密过的字符串','D','nowamagic'); 7 参数说明: 8 $string :需要加密解密的字符串 9 $operation:判断是加密还是解密:E:加密 D:解密 10 $key :加密的钥匙(密匙); 11 *********************************************************************/ 12 function encrypt($string, $operation, $key = 'WMqsfPpS9hwyoJnFP') 13 { 14 $key = md5($key); 15 $key_length = strlen($key); 16 $string = $operation == 'D' ? base64_decode($string) : substr(md5($string . $key), 0, 8) . $string; 17 $string_length = strlen($string); 18 $rndkey = $box = array(); 19 $result = ''; 20 for ($i = 0; $i <= 255; $i++) { 21 $rndkey[$i] = ord($key[$i % $key_length]); 22 $box[$i] = $i; 23 } 24 for ($j = $i = 0; $i < 256; $i++) { 25 $j = ($j + $box[$i] + $rndkey[$i]) % 256; 26 $tmp = $box[$i]; 27 $box[$i] = $box[$j]; 28 $box[$j] = $tmp; 29 } 30 for ($a = $j = $i = 0; $i < $string_length; $i++) { 31 $a = ($a + 1) % 256; 32 $j = ($j + $box[$a]) % 256; 33 $tmp = $box[$a]; 34 $box[$a] = $box[$j]; 35 $box[$j] = $tmp; 36 $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256])); 37 } 38 if ($operation == 'D') { 39 if (substr($result, 0, 8) == substr(md5(substr($result, 8) . $key), 0, 8)) { 40 return substr($result, 8); 41 } else { 42 return ''; 43 } 44 } else { 45 return str_replace('=', '', base64_encode($result)); 46 } 47 }