来一个加密解密的PHP函数,可设置时间!

通过auth::en("加密字符","2023-5-7")和auth::de("需要解密的字符串")来实现加密与解密

设置的时间是过期时间，过期后解密为空

class auth{
static function en($string,$time,$key = "www.dnwfb.com"){
        $time=strtotime($time); 
        $ckey_length = 4;
        $key = md5($key);
        $keya = md5(substr($key, 0, 16));
        $keyb = md5(substr($key, 16, 16));
        $keyc = $ckey_length ? substr($key, 0, $ckey_length) : "";
        $cryptkey = $keya . md5($keya . $keyc);
        $key_length = strlen($cryptkey);
        $string =$time.substr(md5($string. $keyb), 0, 16). $string;
        $string_length = strlen($string);
        $result = "";
        $box = range(0, 255);
        $rndkey = array();
        for ($i = 0; $i <= 255; $i++) {
            $rndkey[$i] = ord($cryptkey[$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;
        }