如何使用token

<?phpdefine('KEY', '#^DKHSD&*F'); // 定义密钥$id = '123';$token = genToken($id);echo 'id encrypt token='.$token.'<br>';echo 'token decrypt id='.checkToken($token);// 创建tokenfunction genToken($id){    $str = json_encode(array(time(),mt_rand(1000,9999),$id));    return authcode($str, 'ENCODE', KEY);}// 验证tokenfunction checkToken($token){    $str = authcode($token, 'DECODE', KEY);    $result = json_decode($str);    if(is_array($result)){        return $result[2];    }else{        return 'decrypt fail';    }}// 加密/解密方法function authcode($string, $operation = 'DECODE', $key){    $ckey_length = 4;   // 随机密钥长度 取值 0-32;    $key = md5($key);    $keya = md5(substr($key, 0, 16));    $keyb = md5(substr($key, 16, 16));    $keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';    $cryptkey = $keya.md5($keya.$keyc);    $key_length = strlen($cryptkey);    $string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', 0).substr(md5($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 % $key_length]);    }    for($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, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {            return substr($result, 26);        } else {            return '';        }    } else {        return $keyc.str_replace('=', '', base64_encode($result));    }}?>