Implementing trusted_proxies CIDR notation capability for IPv6

config/config.sample.php

@@ -1523,9 +1523,7 @@
  * - IPv4 addresses, e.g. `192.168.2.123`
  * - IPv4 ranges in CIDR notation, e.g. `192.168.2.0/24`
  * - IPv6 addresses, e.g. `fd9e:21a7:a92c:2323::1`
- *
- * _(CIDR notation for IPv6 is currently work in progress and thus not
- * available as of yet)_
+ * - IPv6 ranges in CIDR notation, e.g. `fd9e:21a7:a92c:2323::/64`
  *
  * When an incoming request's `REMOTE_ADDR` matches any of the IP addresses
  * specified here, it is assumed to be a proxy instead of a client. Thus, the

lib/private/AppFramework/Http/Request.php

@@ -13,6 +13,7 @@
  * @author Lukas Reschke <lukas@statuscode.ch>
  * @author Mitar <mitar.git@tnode.com>
  * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Oliver Wegner <void1976@gmail.com>
  * @author Robin Appelman <robin@icewind.nl>
  * @author Robin McCorkell <robin@mccorkell.me.uk>
  * @author Roeland Jago Douma <roeland@famdouma.nl>
@@ -43,6 +44,7 @@
 use OC\Security\TrustedDomainHelper;
 use OCP\IConfig;
 use OCP\IRequest;
+use OCP\Net\IIpAddressFactory;
 use OCP\Security\ICrypto;
 use OCP\Security\ISecureRandom;
 
@@ -111,6 +113,8 @@ class Request implements \ArrayAccess, \Countable, IRequest {
 	protected $crypto;
 	/** @var CsrfTokenManager|null */
 	protected $csrfTokenManager;
+	/** @var IIpAddressFactory */
+	protected $ipAddressFactory;
 
 	/** @var bool */
 	protected $contentDecoded = false;
@@ -136,12 +140,14 @@ public function __construct(array $vars= [],
 								ISecureRandom $secureRandom = null,
 								IConfig $config,
 								CsrfTokenManager $csrfTokenManager = null,
-								string $stream = 'php://input') {
+								string $stream = 'php://input',
+								IIpAddressFactory $ipAddressFactory = null) {
 		$this->inputStream = $stream;
 		$this->items['params'] = [];
 		$this->secureRandom = $secureRandom;
 		$this->config = $config;
 		$this->csrfTokenManager = $csrfTokenManager;
+		$this->ipAddressFactory = $ipAddressFactory;
 
 		if(!array_key_exists('method', $vars)) {
 			$vars['method'] = 'GET';
@@ -598,42 +604,28 @@ public function getId(): string {
 		return $this->requestId;
 	}
 
-	/**
-	 * Checks if given $remoteAddress matches given $trustedProxy.
-	 * If $trustedProxy is an IPv4 IP range given in CIDR notation, true will be returned if
-	 * $remoteAddress is an IPv4 address within that IP range.
-	 * Otherwise $remoteAddress will be compared to $trustedProxy literally and the result
-	 * will be returned.
-	 * @return boolean true if $remoteAddress matches $trustedProxy, false otherwise
-	 */
-	protected function matchesTrustedProxy($trustedProxy, $remoteAddress) {
-		$cidrre = '/^([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})\/([0-9]{1,2})$/';
-
-		if (preg_match($cidrre, $trustedProxy, $match)) {
-			$net = $match[1];
-			$shiftbits = min(32, max(0, 32 - intval($match[2])));
-			$netnum = ip2long($net) >> $shiftbits;
-			$ipnum = ip2long($remoteAddress) >> $shiftbits;
-
-			return $ipnum === $netnum;
-		}
-
-		return $trustedProxy === $remoteAddress;
-	}
-
 	/**
 	 * Checks if given $remoteAddress matches any entry in the given array $trustedProxies.
-	 * For details regarding what "match" means, refer to `matchesTrustedProxy`.
+	 * 'Matching' here means
+	 * - $remoteAddress is either equal to an entry in $trustedProxies   or
+	 * - $remoteAddress is an IP address in the range of any IP ranges specified in $trustedProxies
 	 * @return boolean true if $remoteAddress matches any entry in $trustedProxies, false otherwise
 	 */
 	protected function isTrustedProxy($trustedProxies, $remoteAddress) {
-		foreach ($trustedProxies as $tp) {
-			if ($this->matchesTrustedProxy($tp, $remoteAddress)) {
-				return true;
+		if ($this->ipAddressFactory !== null) {
+			$ipAddressRemote = $this->ipAddressFactory->getInstance($remoteAddress);
+
+			foreach ($trustedProxies as $tp) {
+				$ipAddressProxy = $this->ipAddressFactory->getInstance($tp);
+				if ($ipAddressProxy->containsAddress($ipAddressRemote)) {
+					return true;
+				}
 			}
-		}
 
-		return false;
+			return false;
+		} else {
+			return \in_array($remoteAddress, $trustedProxies);
+		}
 	}
 
 	/**

lib/private/Net/AbstractIpAddress.php

@@ -0,0 +1,149 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018, Oliver Wegner (void1976@gmail.com)
+ *
+ * @author Oliver Wegner <void1976@gmail.com>
+ *
+ * @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\Net;
+
+use OCP\Net\IIpAddress;
+
+abstract class AbstractIpAddress implements IIpAddress {
+	abstract public function getMaxBitlength(): int;
+	abstract protected function getCidrRegex(): string;
+	abstract protected function matchCidr(IIpAddress $other): bool;
+
+	protected $original = '';
+	protected $netPart = '';
+	protected $netmaskBits = 0;
+
+	/**
+	 * Constructor that takes an IP address in string form and
+	 * initializes this instance to represent that address
+	 *
+	 * @param string $address
+	 */
+	public function __construct(string $address) {
+		$this->setOriginal($address);
+
+		if (preg_match($this->getCidrRegex(), $address, $match)) {
+			$this->setNetPart($match[1]);
+			$this->setNetmaskBits(max(0, min($this->getMaxBitlength(), intval($match[2]))));
+		} else {
+			$this->setNetPart($address);
+			$this->setNetmaskbits($this->getMaxBitlength());
+		}
+	}
+
+	/**
+	 * Sets the literal address string that this instance
+	 * represents
+	 *
+	 * @param string $original
+	 */
+	protected function setOriginal(string $original) {
+		$this->original = $original;
+	}
+
+	/**
+	 * Returns the literal address string that this instance
+	 * represents
+	 *
+	 * @return string
+	 */
+	protected function getOriginal(): string {
+		return $this->original;
+	}
+
+	/**
+	 * Sets the network part of the
+	 * address/range represented by this instance
+	 *
+	 * @param string $netPart
+	 */
+	protected function setNetPart(string $netPart) {
+		$this->netPart = $netPart;
+	}
+
+	/**
+	 * Returns the network part of the
+	 * address/range represented by this instance
+	 *
+	 * @return string
+	 */
+	protected function getNetPart(): string {
+		return $this->netPart;
+	}
+
+	/**
+	 * Sets the number of bits of the net part of the IP
+	 * address/range represented by this instance
+	 *
+	 * @param int $bits
+	 */
+	protected function setNetmaskBits(int $bits) {
+		$this->netmaskBits = $bits;
+	}
+
+	/**
+	 * Returns the number of bits of the net part of the IP
+	 * address/range represented by this instance
+	 *
+	 * @return int
+	 */
+	protected function getNetmaskBits(): int {
+		return $this->netmaskBits;
+	}
+
+	/**
+	 * Returns whether $other is literally equivalent to this instance
+	 *
+	 * @return bool
+	 */
+	protected function matchOriginal(IIpAddress $other): bool {
+		return $other->getOriginal() === $this->getOriginal();
+	}
+
+	/**
+	 * Returns whether this instance represents an IP range (vs.
+	 * a single IP address)
+	 *
+	 * @return bool
+	 */
+	public function isRange(): bool {
+		return $this->getNetmaskBits() < $this->getMaxBitlength();
+	}
+
+	/**
+	 * Returns whether given $other address is either
+	 * - equal to this instance regarding its IP address   or
+	 * - is contained in the IP address range represented by this instance
+	 *
+	 * @param IIpAddress $other
+	 * @return bool
+	 */
+	public function containsAddress(IIpAddress $other): bool {
+		return $this->isRange()
+			? $this->matchCidr($other)
+			: $this->matchOriginal($other);
+	}
+}
+

lib/private/Net/IpAddressFactory.php

@@ -0,0 +1,63 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018, Oliver Wegner (void1976@gmail.com)
+ *
+ * @author Oliver Wegner <void1976@gmail.com>
+ *
+ * @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\Net;
+
+use OCP\Net\IIpAddressFactory;
+use OCP\Net\IIpAddress;
+use OC\Net\IpAddressV4;
+use OC\Net\IpAddressV6;
+
+/**
+ * This factory creates instances of IIpAddress, given an IP address
+ * string (e.g. "192.168.1.2" or subnet string in CIDR format (e.g.
+ * "192.168.1.0/24").
+ */
+class IpAddressFactory implements IIpAddressFactory {
+	/**
+	 * Returns whether $address represents an IPv6 address
+	 *
+	 * @param string $address
+	 * @return bool
+	 */
+	protected static function isIpv6(string $address): bool {
+		return strpos($address, ':') !== false;
+	}
+
+	/**
+	 * Creates a new instance conforming to IIpAddress and
+	 * representing the given $address.
+	 *
+	 * @param string $address
+	 * @return IIpAddress
+	 */
+	public function getInstance(string $address): IIpAddress {
+		if (self::isIpv6($address)) {
+			return new IpAddressV6($address);
+		} else {
+			return new IpAddressV4($address);
+		}
+	}
+}
+

lib/private/Net/IpAddressV4.php

@@ -0,0 +1,65 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018, Oliver Wegner (void1976@gmail.com)
+ *
+ * @author Oliver Wegner <void1976@gmail.com>
+ *
+ * @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\Net;
+
+use OCP\Net\IIpAddress;
+use OC\Net\AbstractIpAddress;
+
+class IpAddressV4 extends AbstractIpAddress {
+	/**
+	 * Returns the length of the represented IP address format in bits.
+	 *
+	 * @return int
+	 */
+	public function getMaxBitlength(): int {
+		return 32;
+	}
+
+	/**
+	 * Returns the regular expression for recognizing CIDR notation.
+	 *
+	 * @return string
+	 */
+	protected function getCidrRegex(): string {
+		return '/^([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})\/([0-9]{1,2})$/';
+	}
+
+	/**
+	 * Returns whether given $other address is either
+	 * - equal to this instance regarding its IP address   or
+	 * - is contained in the IP address range represented by this instance
+	 *
+	 * @param IIpAddress $other
+	 * @return bool
+	 */
+	protected function matchCidr(IIpAddress $other): bool {
+		$shiftbits = $this->getMaxBitlength() - $this->getNetmaskBits();
+		$thisnum = ip2long($this->getNetPart()) >> $shiftbits;
+		$othernum = ip2long($other->getNetPart()) >> $shiftbits;
+
+		return $othernum === $thisnum;
+	}
+}
+