<?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 <[email protected]>
* @license http://opensource.org/licenses/MIT MIT
*/
declare(strict_types=1);
namespace Ramsey\Uuid\Provider\Dce;
use Ramsey\Uuid\Exception\DceSecurityException;
use Ramsey\Uuid\Provider\DceSecurityProviderInterface;
use Ramsey\Uuid\Type\Integer as IntegerObject;
use function escapeshellarg;
use function preg_split;
use function str_getcsv;
use function strpos;
use function strrpos;
use function strtolower;
use function strtoupper;
use function substr;
use function trim;
use const PREG_SPLIT_NO_EMPTY;
/**
* SystemDceSecurityProvider retrieves the user or group identifiers from the system
*/
class SystemDceSecurityProvider implements DceSecurityProviderInterface
{
/**
* @throws DceSecurityException if unable to get a user identifier
*
* @inheritDoc
*/
public function getUid(): IntegerObject
{
static $uid = null;
if ($uid instanceof IntegerObject) {
return $uid;
}
if ($uid === null) {
$uid = $this->getSystemUid();
}
if ($uid === '') {
throw new DceSecurityException(
'Unable to get a user identifier using the system DCE '
. 'Security provider; please provide a custom identifier or '
. 'use a different provider'
);
}
$uid = new IntegerObject($uid);
return $uid;
}
/**
* @throws DceSecurityException if unable to get a group identifier
*
* @inheritDoc
*/
public function getGid(): IntegerObject
{
static $gid = null;
if ($gid instanceof IntegerObject) {
return $gid;
}
if ($gid === null) {
$gid = $this->getSystemGid();
}
if ($gid === '') {
throw new DceSecurityException(
'Unable to get a group identifier using the system DCE '
. 'Security provider; please provide a custom identifier or '
. 'use a different provider'
);
}
$gid = new IntegerObject($gid);
return $gid;
}
/**
* Returns the UID from the system
*/
private function getSystemUid(): string
{
if (!$this->hasShellExec()) {
return '';
}
switch ($this->getOs()) {
case 'WIN':
return $this->getWindowsUid();
case 'DAR':
case 'FRE':
case 'LIN':
default:
return trim((string) shell_exec('id -u'));
}
}
/**
* Returns the GID from the system
*/
private function getSystemGid(): string
{
if (!$this->hasShellExec()) {
return '';
}
switch ($this->getOs()) {
case 'WIN':
return $this->getWindowsGid();
case 'DAR':
case 'FRE':
case 'LIN':
default:
return trim((string) shell_exec('id -g'));
}
}
/**
* Returns true if shell_exec() is available for use
*/
private function hasShellExec(): bool
{
$disabledFunctions = strtolower((string) ini_get('disable_functions'));
return strpos($disabledFunctions, 'shell_exec') === false;
}
/**
* Returns the PHP_OS string
*/
private function getOs(): string
{
return strtoupper(substr(constant('PHP_OS'), 0, 3));
}
/**
* Returns the user identifier for a user on a Windows system
*
* Windows does not have the same concept as an effective POSIX UID for the
* running script. Instead, each user is uniquely identified by an SID
* (security identifier). The SID includes three 32-bit unsigned integers
* that make up a unique domain identifier, followed by an RID (relative
* identifier) that we will use as the UID. The primary caveat is that this
* UID may not be unique to the system, since it is, instead, unique to the
* domain.
*
* @link https://www.lifewire.com/what-is-an-sid-number-2626005 What Is an SID Number?
* @link https://bit.ly/30vE7NM Well-known SID Structures
* @link https://bit.ly/2FWcYKJ Well-known security identifiers in Windows operating systems
* @link https://www.windows-commandline.com/get-sid-of-user/ Get SID of user
*/
private function getWindowsUid(): string
{
$response = shell_exec('whoami /user /fo csv /nh');
if ($response === null) {
return '';
}
$sid = str_getcsv(trim((string) $response))[1] ?? '';
if (($lastHyphen = strrpos($sid, '-')) === false) {
return '';
}
return trim(substr($sid, $lastHyphen + 1));
}
/**
* Returns a group identifier for a user on a Windows system
*
* Since Windows does not have the same concept as an effective POSIX GID
* for the running script, we will get the local group memberships for the
* user running the script. Then, we will get the SID (security identifier)
* for the first group that appears in that list. Finally, we will return
* the RID (relative identifier) for the group and use that as the GID.
*
* @link https://www.windows-commandline.com/list-of-user-groups-command-line/ List of user groups command line
*/
private function getWindowsGid(): string
{
$response = shell_exec('net user %username% | findstr /b /i "Local Group Memberships"');
if ($response === null) {
return '';
}
/** @var string[] $userGroups */
$userGroups = preg_split('/\s{2,}/', (string) $response, -1, PREG_SPLIT_NO_EMPTY);
$firstGroup = trim($userGroups[1] ?? '', "* \t\n\r\0\x0B");
if ($firstGroup === '') {
return '';
}
$response = shell_exec('wmic group get name,sid | findstr /b /i ' . escapeshellarg($firstGroup));
if ($response === null) {
return '';
}
/** @var string[] $userGroup */
$userGroup = preg_split('/\s{2,}/', (string) $response, -1, PREG_SPLIT_NO_EMPTY);
$sid = $userGroup[1] ?? '';
if (($lastHyphen = strrpos($sid, '-')) === false) {
return '';
}
return trim((string) substr($sid, $lastHyphen + 1));
}
}