<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Uid;
/**
* A v6 UUID is lexicographically sortable and contains a 60-bit timestamp and 62 extra unique bits.
*
* Unlike UUIDv1, this implementation of UUIDv6 doesn't leak the MAC address of the host.
*
* @author Nicolas Grekas <[email protected]>
*/
class UuidV6 extends Uuid
{
protected const TYPE = 6;
private static string $node;
public function __construct(string $uuid = null)
{
if (null === $uuid) {
$this->uid = static::generate();
} else {
parent::__construct($uuid, true);
}
}
public function getDateTime(): \DateTimeImmutable
{
return BinaryUtil::hexToDateTime('0'.substr($this->uid, 0, 8).substr($this->uid, 9, 4).substr($this->uid, 15, 3));
}
public function getNode(): string
{
return substr($this->uid, 24);
}
public static function generate(\DateTimeInterface $time = null, Uuid $node = null): string
{
$uuidV1 = UuidV1::generate($time, $node);
$uuid = substr($uuidV1, 15, 3).substr($uuidV1, 9, 4).$uuidV1[0].'-'.substr($uuidV1, 1, 4).'-6'.substr($uuidV1, 5, 3).substr($uuidV1, 18, 6);
if ($node) {
return $uuid.substr($uuidV1, 24);
}
// uuid_create() returns a stable "node" that can leak the MAC of the host, but
// UUIDv6 prefers a truly random number here, let's XOR both to preserve the entropy
if (!isset(self::$node)) {
$seed = [random_int(0, 0xFFFFFF), random_int(0, 0xFFFFFF)];
$node = unpack('N2', hex2bin('00'.substr($uuidV1, 24, 6)).hex2bin('00'.substr($uuidV1, 30)));
self::$node = sprintf('%06x%06x', ($seed[0] ^ $node[1]) | 0x010000, $seed[1] ^ $node[2]);
}
return $uuid.self::$node;
}
}