Merge pull request #33353 from nextcloud/backport/33031/stable24

[stable24] Improve local IP detection

5 files changed, 206 insertions, 2 deletions

diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index b3b31cae4cc..59939b9cb1f 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -1251,6 +1251,7 @@ return array(
     'OC\\Http\\Client\\NegativeDnsCache' => $baseDir . '/lib/private/Http/Client/NegativeDnsCache.php',
     'OC\\Http\\Client\\Response' => $baseDir . '/lib/private/Http/Client/Response.php',
     'OC\\Http\\CookieHelper' => $baseDir . '/lib/private/Http/CookieHelper.php',
+    'OC\\Http\\IpUtils' => $baseDir . '/lib/private/Http/IpUtils.php',
     'OC\\Http\\WellKnown\\RequestManager' => $baseDir . '/lib/private/Http/WellKnown/RequestManager.php',
     'OC\\InitialStateService' => $baseDir . '/lib/private/InitialStateService.php',
     'OC\\Installer' => $baseDir . '/lib/private/Installer.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index fd2d072e9a8..57ba09046b3 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -1280,6 +1280,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Http\\Client\\NegativeDnsCache' => __DIR__ . '/../../..' . '/lib/private/Http/Client/NegativeDnsCache.php',
         'OC\\Http\\Client\\Response' => __DIR__ . '/../../..' . '/lib/private/Http/Client/Response.php',
         'OC\\Http\\CookieHelper' => __DIR__ . '/../../..' . '/lib/private/Http/CookieHelper.php',
+        'OC\\Http\\IpUtils' => __DIR__ . '/../../..' . '/lib/private/Http/IpUtils.php',
         'OC\\Http\\WellKnown\\RequestManager' => __DIR__ . '/../../..' . '/lib/private/Http/WellKnown/RequestManager.php',
         'OC\\InitialStateService' => __DIR__ . '/../../..' . '/lib/private/InitialStateService.php',
         'OC\\Installer' => __DIR__ . '/../../..' . '/lib/private/Installer.php',
diff --git a/lib/private/Http/Client/LocalAddressChecker.php b/lib/private/Http/Client/LocalAddressChecker.php
index c69d1007a16..da641b57c04 100644
--- a/lib/private/Http/Client/LocalAddressChecker.php
+++ b/lib/private/Http/Client/LocalAddressChecker.php
@@ -27,6 +27,7 @@ namespace OC\Http\Client;
 
 use OCP\Http\Client\LocalServerException;
 use Psr\Log\LoggerInterface;
+use OC\Http\IpUtils;
 
 class LocalAddressChecker {
 	private LoggerInterface $logger;
@@ -36,7 +37,16 @@ class LocalAddressChecker {
 	}
 
 	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)) {
+		$localRanges = [
+			'100.64.0.0/10', // See RFC 6598
+			'192.0.0.0/24', // See RFC 6890
+		];
+		if (
+			(bool)filter_var($ip, FILTER_VALIDATE_IP) &&
+			(
+				!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE) ||
+				IpUtils::checkIp($ip, $localRanges)
+			)) {
 			$this->logger->warning("Host $ip was not connected to because it violates local access rules");
 			throw new LocalServerException('Host violates local access rules');
 		}
@@ -46,7 +56,9 @@ class LocalAddressChecker {
 			$delimiter = strrpos($ip, ':'); // Get last colon
 			$ipv4Address = substr($ip, $delimiter + 1);
 
-			if (!filter_var($ipv4Address, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE)) {
+			if (
+				!filter_var($ipv4Address, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE) ||
+				IpUtils::checkIp($ip, $localRanges)) {
 				$this->logger->warning("Host $ip was not connected to because it violates local access rules");
 				throw new LocalServerException('Host violates local access rules');
 			}
diff --git a/lib/private/Http/IpUtils.php b/lib/private/Http/IpUtils.php
new file mode 100644
index 00000000000..97a3cb9dba1
--- /dev/null
+++ b/lib/private/Http/IpUtils.php
@@ -0,0 +1,185 @@
+<?php
+
+/*
+ * This file comes from Symfony. Copied here to avoid backporting a new dependency.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+namespace OC\Http;
+
+/**
+ * Http utility functions.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class IpUtils {
+	/**
+	 * @var array<string,bool>
+	 */
+	private static $checkedIps = [];
+
+	/**
+	 * This class should not be instantiated.
+	 */
+	private function __construct() {
+	}
+
+	/**
+	 * Checks if an IPv4 or IPv6 address is contained in the list of given IPs or subnets.
+	 *
+	 * @param string|array $ips List of IPs or subnets (can be a string if only a single one)
+	 *
+	 * @return bool
+	 */
+	public static function checkIp(string $requestIp, $ips) {
+		if (!\is_array($ips)) {
+			$ips = [$ips];
+		}
+
+		$method = substr_count($requestIp, ':') > 1 ? 'checkIp6' : 'checkIp4';
+
+		foreach ($ips as $ip) {
+			if (self::$method($requestIp, $ip)) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Compares two IPv4 addresses.
+	 * In case a subnet is given, it checks if it contains the request IP.
+	 *
+	 * @param string $ip IPv4 address or subnet in CIDR notation
+	 *
+	 * @return bool Whether the request IP matches the IP, or whether the request IP is within the CIDR subnet
+	 */
+	public static function checkIp4(string $requestIp, string $ip) {
+		$cacheKey = $requestIp.'-'.$ip;
+		if (isset(self::$checkedIps[$cacheKey])) {
+			return self::$checkedIps[$cacheKey];
+		}
+
+		if (!filter_var($requestIp, \FILTER_VALIDATE_IP, \FILTER_FLAG_IPV4)) {
+			return self::$checkedIps[$cacheKey] = false;
+		}
+
+		if (str_contains($ip, '/')) {
+			[$address, $netmask] = explode('/', $ip, 2);
+
+			if ('0' === $netmask) {
+				return self::$checkedIps[$cacheKey] = (bool)filter_var($address, \FILTER_VALIDATE_IP, \FILTER_FLAG_IPV4);
+			}
+
+			$netmask = (int)$netmask;
+
+			if ($netmask < 0 || $netmask > 32) {
+				return self::$checkedIps[$cacheKey] = false;
+			}
+		} else {
+			$address = $ip;
+			$netmask = 32;
+		}
+
+		if (false === ip2long($address)) {
+			return self::$checkedIps[$cacheKey] = false;
+		}
+
+		return self::$checkedIps[$cacheKey] = 0 === substr_compare(sprintf('%032b', ip2long($requestIp)), sprintf('%032b', ip2long($address)), 0, $netmask);
+	}
+
+	/**
+	 * Compares two IPv6 addresses.
+	 * In case a subnet is given, it checks if it contains the request IP.
+	 *
+	 * @author David Soria Parra <dsp at php dot net>
+	 *
+	 * @see https://github.com/dsp/v6tools
+	 *
+	 * @param string $ip IPv6 address or subnet in CIDR notation
+	 *
+	 * @return bool
+	 *
+	 * @throws \RuntimeException When IPV6 support is not enabled
+	 */
+	public static function checkIp6(string $requestIp, string $ip) {
+		$cacheKey = $requestIp.'-'.$ip;
+		if (isset(self::$checkedIps[$cacheKey])) {
+			return self::$checkedIps[$cacheKey];
+		}
+
+		if (!((\extension_loaded('sockets') && \defined('AF_INET6')) || @inet_pton('::1'))) {
+			throw new \RuntimeException('Unable to check Ipv6. Check that PHP was not compiled with option "disable-ipv6".');
+		}
+
+		if (str_contains($ip, '/')) {
+			[$address, $netmask] = explode('/', $ip, 2);
+
+			if ('0' === $netmask) {
+				return (bool) unpack('n*', @inet_pton($address));
+			}
+
+			$netmask = (int)$netmask;
+
+			if ($netmask < 1 || $netmask > 128) {
+				return self::$checkedIps[$cacheKey] = false;
+			}
+		} else {
+			$address = $ip;
+			$netmask = 128;
+		}
+
+		$bytesAddr = unpack('n*', @inet_pton($address));
+		$bytesTest = unpack('n*', @inet_pton($requestIp));
+
+		if (!$bytesAddr || !$bytesTest) {
+			return self::$checkedIps[$cacheKey] = false;
+		}
+
+		for ($i = 1, $ceil = ceil($netmask / 16); $i <= $ceil; ++$i) {
+			$left = $netmask - 16 * ($i - 1);
+			$left = ($left <= 16) ? $left : 16;
+			$mask = ~(0xFFFF >> $left) & 0xFFFF;
+			if (($bytesAddr[$i] & $mask) != ($bytesTest[$i] & $mask)) {
+				return self::$checkedIps[$cacheKey] = false;
+			}
+		}
+
+		return self::$checkedIps[$cacheKey] = true;
+	}
+
+	/**
+	 * Anonymizes an IP/IPv6.
+	 *
+	 * Removes the last byte for v4 and the last 8 bytes for v6 IPs
+	 */
+	public static function anonymize(string $ip): string {
+		$wrappedIPv6 = false;
+		if ('[' === substr($ip, 0, 1) && ']' === substr($ip, -1, 1)) {
+			$wrappedIPv6 = true;
+			$ip = substr($ip, 1, -1);
+		}
+
+		$packedAddress = inet_pton($ip);
+		if (4 === \strlen($packedAddress)) {
+			$mask = '255.255.255.0';
+		} elseif ($ip === inet_ntop($packedAddress & inet_pton('::ffff:ffff:ffff'))) {
+			$mask = '::ffff:ffff:ff00';
+		} elseif ($ip === inet_ntop($packedAddress & inet_pton('::ffff:ffff'))) {
+			$mask = '::ffff:ff00';
+		} else {
+			$mask = 'ffff:ffff:ffff:ffff:0000:0000:0000:0000';
+		}
+		$ip = inet_ntop($packedAddress & inet_pton($mask));
+
+		if ($wrappedIPv6) {
+			$ip = '['.$ip.']';
+		}
+
+		return $ip;
+	}
+}
diff --git a/tests/lib/Http/Client/LocalAddressCheckerTest.php b/tests/lib/Http/Client/LocalAddressCheckerTest.php
index 0bba1cee5f4..9f2f6c72993 100644
--- a/tests/lib/Http/Client/LocalAddressCheckerTest.php
+++ b/tests/lib/Http/Client/LocalAddressCheckerTest.php
@@ -96,6 +96,8 @@ class LocalAddressCheckerTest extends \Test\TestCase {
 			['10.0.0.1'],
 			['::'],
 			['::1'],
+			['100.100.100.200'],
+			['192.0.0.1'],
 		];
 	}
 
@@ -116,6 +118,9 @@ class LocalAddressCheckerTest extends \Test\TestCase {
 			['another-host.local'],
 			['service.localhost'],
 			['!@#$'], // test invalid url
+			['100.100.100.200'],
+			['192.0.0.1'],
+			['randomdomain.internal'],
 		];
 	}