nextcloud/lib/private/Http/Client/LocalAddressChecker.php

86 lines
3.1 KiB
PHP

<?php
declare(strict_types=1);
/**
* @copyright Copyright (c) 2021, Lukas Reschke <lukas@statuscode.ch>
*
* @author Lukas Reschke <lukas@statuscode.ch>
*
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
namespace OC\Http\Client;
use OCP\ILogger;
use OCP\Http\Client\LocalServerException;
class LocalAddressChecker {
/** @var ILogger */
private $logger;
public function __construct(ILogger $logger) {
$this->logger = $logger;
}
public function ThrowIfLocalIp(string $ip) : void {
if ((bool)filter_var($ip, FILTER_VALIDATE_IP) && !filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
$this->logger->warning("Host $ip was not connected to because it violates local access rules");
throw new LocalServerException('Host violates local access rules');
}
// Also check for IPv6 IPv4 nesting, because that's not covered by filter_var
if ((bool)filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) && substr_count($ip, '.') > 0) {
$delimiter = strrpos($ip, ':'); // Get last colon
$ipv4Address = substr($ip, $delimiter + 1);
if (!filter_var($ipv4Address, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
$this->logger->warning("Host $ip was not connected to because it violates local access rules");
throw new LocalServerException('Host violates local access rules');
}
}
}
public function ThrowIfLocalAddress(string $uri) : void {
$host = parse_url($uri, PHP_URL_HOST);
if ($host === false || $host === null) {
$this->logger->warning("Could not detect any host in $uri");
throw new LocalServerException('Could not detect any host');
}
$host = strtolower($host);
// Remove brackets from IPv6 addresses
if (strpos($host, '[') === 0 && substr($host, -1) === ']') {
$host = substr($host, 1, -1);
}
// Disallow localhost and local network
if ($host === 'localhost' || substr($host, -6) === '.local' || substr($host, -10) === '.localhost') {
$this->logger->warning("Host $host was not connected to because it violates local access rules");
throw new LocalServerException('Host violates local access rules');
}
// Disallow hostname only
if (substr_count($host, '.') === 0 && !(bool)filter_var($host, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
$this->logger->warning("Host $host was not connected to because it violates local access rules");
throw new LocalServerException('Host violates local access rules');
}
$this->ThrowIfLocalIp($host);
}
}