Implementing trusted_proxies CIDR notation capability for IPv6

config/config.sample.php

@@ -1503,9 +1503,7 @@
  * - 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 <[email protected]>
  * @author Mitar <[email protected]>
  * @author Morris Jobke <[email protected]>
+ * @author Oliver Wegner <[email protected]>
  * @author Robin Appelman <[email protected]>
  * @author Robin McCorkell <[email protected]>
  * @author Roeland Jago Douma <[email protected]>
@@ -41,6 +42,8 @@
 use OC\Security\CSRF\CsrfToken;
 use OC\Security\CSRF\CsrfTokenManager;
 use OC\Security\TrustedDomainHelper;
+use OC\Net\IIpAddress;
+use OC\Net\IpAddressFactory;
 use OCP\IConfig;
 use OCP\IRequest;
 use OCP\Security\ICrypto;
@@ -598,37 +601,19 @@ 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) {
+		$ipAddressRemote = IpAddressFactory::new($remoteAddress);
+
 		foreach ($trustedProxies as $tp) {
-			if ($this->matchesTrustedProxy($tp, $remoteAddress)) {
+			$ipAddressProxy = IpAddressFactory::new($tp);
+			if ($ipAddressProxy->containsAddress($ipAddressRemote)) {
 				return true;
 			}
 		}

lib/private/Net/AbstractIpAddress.php

@@ -0,0 +1,148 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018, ownCloud, Inc.
+ *
+ * @author Oliver Wegner <[email protected]>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Net;
+
+use OC\Net\IIpAddress;
+
+abstract class AbstractIpAddress implements IIpAddress {
+	abstract public function getMaxBitlength(): int;
+	abstract protected function getCidrRegex(): string;
+	abstract protected function matchCidr(IIpAddress $other): bool;
+
+	private $original = '';
+	private $netPart = '';
+	private $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/IIpAddress.php

@@ -0,0 +1,58 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018, ownCloud, Inc.
+ *
+ * @author Oliver Wegner <[email protected]>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+/**
+ * Private interface of ownCloud for internal use.
+ * IpAddress interface
+ */
+
+/**
+ * This interface provides functionalities of an IP address or range,
+ * e.g. checking if an IP address is within an IP range.
+ *
+ * @since 15.0.0
+ */
+
+namespace OC\Net;
+
+interface IIpAddress {
+
+	/**
+	 * Returns whether this instance represents an IP range.
+	 *
+	 * @return boolean true if this is an IP range, false if it's a single IP address
+	 * @since 15.0.0
+	 */
+	public function isRange(): bool;
+
+	/**
+	 * Returns if $other is equal to or contained in the IP
+	 * address(es) which this instance represents.
+	 *
+	 * @return boolean true if $other is part of (or equal to) $this in terms of 
+	 *         IP range terms, false otherwise
+	 * @since 15.0.0
+	 */
+	public function containsAddress(IIpAddress $other): bool;
+}
+

lib/private/Net/IpAddressFactory.php

@@ -0,0 +1,56 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018, ownCloud, Inc.
+ *
+ * @author Oliver Wegner <[email protected]>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Net;
+
+use OC\Net\IIpAddress;
+use OC\Net\IpAddressV4;
+use OC\Net\IpAddressV6;
+
+class IpAddressFactory {
+	/**
+	 * Returns whether $address represents an IPv6 address
+	 *
+	 * @param string $address
+	 * @return bool
+	 */
+	public static function isIpv6(string $address): bool {
+		return strpos($address, ':') !== false;
+	}
+
+	/**
+	 * Creates a new instance conforming to IIpAddress and
+	 * representing the given $address.
+	 *
+	 * @param string $address
+	 * @return IIpAddress
+	 */
+	public static function new($address): IIpAddress {
+		if (self::isIpv6($address)) {
+			return new IpAddressV6($address);
+		} else {
+			return new IpAddressV4($address);
+		}
+	}
+}
+