<?php
/**
* This file is part of the ramsey/uuid library
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*
* @copyright Copyright (c) Ben Ramsey <ben@benramsey.com>
* @license http://opensource.org/licenses/MIT MIT
*/
declare(strict_types=1);
namespace Ramsey\Uuid\Generator;
use Ramsey\Uuid\Converter\NumberConverterInterface;
use Ramsey\Uuid\Exception\DceSecurityException;
use Ramsey\Uuid\Provider\DceSecurityProviderInterface;
use Ramsey\Uuid\Type\Hexadecimal;
use Ramsey\Uuid\Type\Integer as IntegerObject;
use Ramsey\Uuid\Uuid;
use function hex2bin;
use function in_array;
use function pack;
use function str_pad;
use function strlen;
use function substr_replace;
use const STR_PAD_LEFT;
/**
* DceSecurityGenerator generates strings of binary data based on a local
* domain, local identifier, node ID, clock sequence, and the current time
*/
class DceSecurityGenerator implements DceSecurityGeneratorInterface
{
private const DOMAINS = [
Uuid::DCE_DOMAIN_PERSON,
Uuid::DCE_DOMAIN_GROUP,
Uuid::DCE_DOMAIN_ORG,
];
/**
* Upper bounds for the clock sequence in DCE Security UUIDs.
*/
private const CLOCK_SEQ_HIGH = 63;
/**
* Lower bounds for the clock sequence in DCE Security UUIDs.
*/
private const CLOCK_SEQ_LOW = 0;
/**
* @var NumberConverterInterface
*/
private $numberConverter;
/**
* @var TimeGeneratorInterface
*/
private $timeGenerator;
/**
* @var DceSecurityProviderInterface
*/
private $dceSecurityProvider;
public function __construct(
NumberConverterInterface $numberConverter,
TimeGeneratorInterface $timeGenerator,
DceSecurityProviderInterface $dceSecurityProvider
) {
$this->numberConverter = $numberConverter;
$this->timeGenerator = $timeGenerator;
$this->dceSecurityProvider = $dceSecurityProvider;
}
public function generate(
int $localDomain,
?IntegerObject $localIdentifier = null,
?Hexadecimal $node = null,
?int $clockSeq = null
): string {
if (!in_array($localDomain, self::DOMAINS)) {
throw new DceSecurityException(
'Local domain must be a valid DCE Security domain'
);
}
if ($localIdentifier && $localIdentifier->isNegative()) {
throw new DceSecurityException(
'Local identifier out of bounds; it must be a value between 0 and 4294967295'
);
}
if ($clockSeq > self::CLOCK_SEQ_HIGH || $clockSeq < self::CLOCK_SEQ_LOW) {
throw new DceSecurityException(
'Clock sequence out of bounds; it must be a value between 0 and 63'
);
}
switch ($localDomain) {
case Uuid::DCE_DOMAIN_ORG:
if ($localIdentifier === null) {
throw new DceSecurityException(
'A local identifier must be provided for the org domain'
);
}
break;
case Uuid::DCE_DOMAIN_PERSON:
if ($localIdentifier === null) {
$localIdentifier = $this->dceSecurityProvider->getUid();
}
break;
case Uuid::DCE_DOMAIN_GROUP:
default:
if ($localIdentifier === null) {
$localIdentifier = $this->dceSecurityProvider->getGid();
}
break;
}
$identifierHex = $this->numberConverter->toHex($localIdentifier->toString());
// The maximum value for the local identifier is 0xffffffff, or
// 4294967295. This is 8 hexadecimal digits, so if the length of
// hexadecimal digits is greater than 8, we know the value is greater
// than 0xffffffff.
if (strlen($identifierHex) > 8) {
throw new DceSecurityException(
'Local identifier out of bounds; it must be a value between 0 and 4294967295'
);
}
$domainByte = pack('n', $localDomain)[1];
$identifierBytes = (string) hex2bin(str_pad($identifierHex, 8, '0', STR_PAD_LEFT));
if ($node instanceof Hexadecimal) {
$node = $node->toString();
}
// Shift the clock sequence 8 bits to the left, so it matches 0x3f00.
if ($clockSeq !== null) {
$clockSeq = $clockSeq << 8;
}
$bytes = $this->timeGenerator->generate($node, $clockSeq);
// Replace bytes in the time-based UUID with DCE Security values.
$bytes = substr_replace($bytes, $identifierBytes, 0, 4);
$bytes = substr_replace($bytes, $domainByte, 9, 1);
return $bytes;
}
}