Add OCP\Security\IHasher

Public interface for hashing which also works with legacy ownCloud hashes and supports updating the legacy hash via a passed reference.

Follow-up of https://github.com/owncloud/core/pull/10219#issuecomment-61624662
Requires https://github.com/owncloud/3rdparty/pull/136

3rdparty

@@ -1 +1 @@
-Subproject commit cb394f1eb0a363268325d181b22df69ad91d6e1b
+Subproject commit 48fdf111dfe4728a906002afccb97b8ad88b3f61

config/config.sample.php

@@ -57,6 +57,12 @@ $CONFIG = array(
  */
 'passwordsalt' => '',
 
+/**
+ * The hashing cost used by hashes generated by ownCloud
+ * Using a higher value requires more time and CPU power to calculate the hashes
+ */
+'hashingCost' => 10,
+
 /**
  * Your list of trusted domains that users can log into. Specifying trusted
  * domains prevents host header poisoning. Do not remove this, as it performs

lib/private/security/hasher.php

@@ -0,0 +1,146 @@
+<?php
+/**
+ * Copyright (c) 2014 Lukas Reschke <lukas@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\Security;
+
+use OCP\IConfig;
+use OCP\Security\IHasher;
+
+/**
+ * Class Hasher provides some basic hashing functions. Furthermore, it supports legacy hashes
+ * used by previous versions of ownCloud and helps migrating those hashes to newer ones.
+ *
+ * The hashes generated by this class are prefixed (version|hash) with a version parameter to allow possible
+ * updates in the future.
+ * Possible versions:
+ * 	- 1 (Initial version)
+ *
+ * Usage:
+ * // Hashing a message
+ * $hash = \OC::$server->getHasher()->hash('MessageToHash');
+ * // Verifying a message - $newHash will contain the newly calculated hash
+ * $newHash = null;
+ * var_dump(\OC::$server->getHasher()->verify('a', '86f7e437faa5a7fce15d1ddcb9eaeaea377667b8', $newHash));
+ * var_dump($newHash);
+ *
+ * @package OC\Security
+ */
+class Hasher implements IHasher {
+	/** @var IConfig */
+	private $config;
+	/** @var array Options passed to password_hash and password_needs_rehash */
+	private $options = array();
+	/** @var string Salt used for legacy passwords */
+	private $legacySalt = null;
+	/** @var int Current version of the generated hash */
+	private $currentVersion = 1;
+
+	/**
+	 * @param IConfig $config
+	 */
+	function __construct(IConfig $config) {
+		$this->config = $config;
+
+		$hashingCost = $this->config->getSystemValue('hashingCost', null);
+		if(!is_null($hashingCost)) {
+			$this->options['cost'] = $hashingCost;
+		}
+	}
+
+	/**
+	 * Hashes a message using PHP's `password_hash` functionality.
+	 * Please note that the size of the returned string is not guaranteed
+	 * and can be up to 255 characters.
+	 *
+	 * @param string $message Message to generate hash from
+	 * @return string Hash of the message with appended version parameter
+	 */
+	public function hash($message) {
+		return $this->currentVersion . '|' . password_hash($message, PASSWORD_DEFAULT, $this->options);
+	}
+
+	/**
+	 * Get the version and hash from a prefixedHash
+	 * @param string $prefixedHash
+	 * @return null|array Null if the hash is not prefixed, otherwise array('version' => 1, 'hash' => 'foo')
+	 */
+	protected function splitHash($prefixedHash) {
+		$explodedString = explode('|', $prefixedHash, 2);
+		if(sizeof($explodedString) === 2) {
+			if((int)$explodedString[0] > 0) {
+				return array('version' => (int)$explodedString[0], 'hash' => $explodedString[1]);
+			}
+		}
+
+		return null;
+	}
+
+	/**
+	 * Verify legacy hashes
+	 * @param string $message Message to verify
+	 * @param string $hash Assumed hash of the message
+	 * @param null|string &$newHash Reference will contain the updated hash
+	 * @return bool Whether $hash is a valid hash of $message
+	 */
+	protected function legacyHashVerify($message, $hash, &$newHash = null) {
+		if(empty($this->legacySalt)) {
+			$this->legacySalt = $this->config->getSystemValue('passwordsalt', '');
+		}
+
+		// Verify whether it matches a legacy PHPass or SHA1 string
+		$hashLength = strlen($hash);
+		if($hashLength === 60 && password_verify($message.$this->legacySalt, $hash) ||
+			$hashLength === 40 && StringUtils::equals($hash, sha1($message))) {
+			$newHash = $this->hash($message);
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Verify V1 hashes
+	 * @param string $message Message to verify
+	 * @param string $hash Assumed hash of the message
+	 * @param null|string &$newHash Reference will contain the updated hash if necessary. Update the existing hash with this one.
+	 * @return bool Whether $hash is a valid hash of $message
+	 */
+	protected function verifyHashV1($message, $hash, &$newHash = null) {
+		if(password_verify($message, $hash)) {
+			if(password_needs_rehash($hash, PASSWORD_DEFAULT, $this->options)) {
+				$newHash = $this->hash($message);
+			}
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * @param string $message Message to verify
+	 * @param string $hash Assumed hash of the message
+	 * @param null|string &$newHash Reference will contain the updated hash if necessary. Update the existing hash with this one.
+	 * @return bool Whether $hash is a valid hash of $message
+	 */
+	public function verify($message, $hash, &$newHash = null) {
+		$splittedHash = $this->splitHash($hash);
+
+		if(isset($splittedHash['version'])) {
+			switch ($splittedHash['version']) {
+				case 1:
+					return $this->verifyHashV1($message, $splittedHash['hash'], $newHash);
+			}
+		} else {
+			return $this->legacyHashVerify($message, $hash, $newHash);
+		}
+
+
+		return false;
+	}
+
+}

lib/private/server.php

@@ -14,6 +14,7 @@ use OC\DB\ConnectionWrapper;
 use OC\Files\Node\Root;
 use OC\Files\View;
 use OC\Security\Crypto;
+use OC\Security\Hasher;
 use OC\Security\SecureRandom;
 use OC\Diagnostics\NullEventLogger;
 use OCP\IServerContainer;
@@ -197,6 +198,9 @@ class Server extends SimpleContainer implements IServerContainer {
 		$this->registerService('Crypto', function (Server $c) {
 			return new Crypto($c->getConfig(), $c->getSecureRandom());
 		});
+		$this->registerService('Hasher', function (Server $c) {
+			return new Hasher($c->getConfig());
+		});
 		$this->registerService('DatabaseConnection', function (Server $c) {
 			$factory = new \OC\DB\ConnectionFactory();
 			$type = $c->getConfig()->getSystemValue('dbtype', 'sqlite');
@@ -529,6 +533,15 @@ class Server extends SimpleContainer implements IServerContainer {
 		return $this->query('Crypto');
 	}
 
+	/**
+	 * Returns a Hasher instance
+	 *
+	 * @return \OCP\Security\IHasher
+	 */
+	function getHasher() {
+		return $this->query('Hasher');
+	}
+
 	/**
 	 * Returns an instance of the db facade
 	 *

lib/public/iservercontainer.php

@@ -128,6 +128,19 @@ interface IServerContainer {
 	 */
 	function getConfig();
 
+	/**
+	 * Returns a Crypto instance
+	 *
+	 * @return \OCP\Security\ICrypto
+	 */
+	function getCrypto();
+
+	/**
+	 * Returns a Hasher instance
+	 *
+	 * @return \OCP\Security\IHasher
+	 */
+	function getHasher();
 
 	/**
 	 * Returns an instance of the db facade

lib/public/security/ihasher.php

@@ -0,0 +1,48 @@
+<?php
+/**
+ * Copyright (c) 2014 Lukas Reschke <lukas@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OCP\Security;
+
+/**
+ * Class Hasher provides some basic hashing functions. Furthermore, it supports legacy hashes
+ * used by previous versions of ownCloud and helps migrating those hashes to newer ones.
+ *
+ * The hashes generated by this class are prefixed (version|hash) with a version parameter to allow possible
+ * updates in the future.
+ * Possible versions:
+ * 	- 1 (Initial version)
+ *
+ * Usage:
+ * // Hashing a message
+ * $hash = \OC::$server->getHasher()->hash('MessageToHash');
+ * // Verifying a message - $newHash will contain the newly calculated hash
+ * $newHash = null;
+ * var_dump(\OC::$server->getHasher()->verify('a', '86f7e437faa5a7fce15d1ddcb9eaeaea377667b8', $newHash));
+ * var_dump($newHash);
+ *
+ * @package OCP\Security
+ */
+interface IHasher {
+	/**
+	 * Hashes a message using PHP's `password_hash` functionality.
+	 * Please note that the size of the returned string is not guaranteed
+	 * and can be up to 255 characters.
+	 *
+	 * @param string $message Message to generate hash from
+	 * @return string Hash of the message with appended version parameter
+	 */
+	public function hash($message);
+
+	/**
+	 * @param string $message Message to verify
+	 * @param string $hash Assumed hash of the message
+	 * @param null|string &$newHash Reference will contain the updated hash if necessary. Update the existing hash with this one.
+	 * @return bool Whether $hash is a valid hash of $message
+	 */
+	public function verify($message, $hash, &$newHash = null);
+}

tests/lib/security/hasher.php

@@ -0,0 +1,115 @@
+<?php
+/**
+ * Copyright (c) 2014 Lukas Reschke <lukas@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+use OC\Security\Hasher;
+
+/**
+ * Class HasherTest
+ */
+class HasherTest extends \PHPUnit_Framework_TestCase {
+
+	/**
+	 * @return array
+	 */
+	public function versionHashProvider()
+	{
+		return array(
+			array('asf32äà$$a.|3', null),
+			array('asf32äà$$a.|3|5', null),
+			array('1|2|3|4', array('version' => 1, 'hash' => '2|3|4')),
+			array('1|我看|这本书。 我看這本書', array('version' => 1, 'hash' => '我看|这本书。 我看這本書'))
+		);
+	}
+
+	/**
+	 * @return array
+	 */
+	public function allHashProviders()
+	{
+		return array(
+			// Bogus values
+			array(null, 'asf32äà$$a.|3', false),
+			array(null, false, false),
+
+			// Valid SHA1 strings
+			array('password', '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8', true),
+			array('owncloud.com', '27a4643e43046c3569e33b68c1a4b15d31306d29', true),
+
+			// Invalid SHA1 strings
+			array('InvalidString', '5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8', false),
+			array('AnotherInvalidOne', '27a4643e43046c3569e33b68c1a4b15d31306d29', false),
+
+			// Valid legacy password string with password salt "6Wow67q1wZQZpUUeI6G2LsWUu4XKx"
+			array('password', '$2a$08$emCpDEl.V.QwPWt5gPrqrOhdpH6ailBmkj2Hd2vD5U8qIy20HBe7.', true),
+			array('password', '$2a$08$yjaLO4ev70SaOsWZ9gRS3eRSEpHVsmSWTdTms1949mylxJ279hzo2', true),
+			array('password', '$2a$08$.jNRG/oB4r7gHJhAyb.mDupNUAqTnBIW/tWBqFobaYflKXiFeG0A6', true),
+			array('owncloud.com', '$2a$08$YbEsyASX/hXVNMv8hXQo7ezreN17T8Jl6PjecGZvpX.Ayz2aUyaZ2', true),
+			array('owncloud.com', '$2a$11$cHdDA2IkUP28oNGBwlL7jO/U3dpr8/0LIjTZmE8dMPA7OCUQsSTqS', true),
+			array('owncloud.com', '$2a$08$GH.UoIfJ1e.qeZ85KPqzQe6NR8XWRgJXWIUeE1o/j1xndvyTA1x96', true),
+
+			// Invalid legacy passwords
+			array('password', '$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false),
+
+			// Valid passwords "6Wow67q1wZQZpUUeI6G2LsWUu4XKx"
+			array('password', '1|$2a$05$ezAE0dkwk57jlfo6z5Pql.gcIK3ReXT15W7ITNxVS0ksfhO/4E4Kq', true),
+			array('password', '1|$2a$05$4OQmloFW4yTVez2MEWGIleDO9Z5G9tWBXxn1vddogmKBQq/Mq93pe', true),
+			array('password', '1|$2a$11$yj0hlp6qR32G9exGEXktB.yW2rgt2maRBbPgi3EyxcDwKrD14x/WO', true),
+			array('owncloud.com', '1|$2a$10$Yiss2WVOqGakxuuqySv5UeOKpF8d8KmNjuAPcBMiRJGizJXjA2bKm', true),
+			array('owncloud.com', '1|$2a$10$v9mh8/.mF/Ut9jZ7pRnpkuac3bdFCnc4W/gSumheQUi02Sr.xMjPi', true),
+			array('owncloud.com', '1|$2a$05$ST5E.rplNRfDCzRpzq69leRzsTGtY7k88h9Vy2eWj0Ug/iA9w5kGK', true),
+
+			// Invalid passwords
+			array('password', '0|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false),
+			array('password', '1|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false),
+			array('password', '2|$2a$08$oKAQY5IhnZocP.61MwP7xu7TNeOb7Ostvk3j6UpacvaNMs.xRj7O2', false),
+		);
+	}
+
+
+
+	/** @var Hasher */
+	protected $hasher;
+	/** @var \OCP\IConfig */
+	protected $config;
+
+	protected function setUp() {
+		$this->config = $this->getMockBuilder('\OCP\IConfig')
+			->disableOriginalConstructor()->getMock();
+
+		$this->hasher = new Hasher($this->config);
+	}
+
+	function testHash() {
+		$hash = $this->hasher->hash('String To Hash');
+		$this->assertNotNull($hash);
+	}
+
+	/**
+	 * @dataProvider versionHashProvider
+	 */
+	function testSplitHash($hash, $expected) {
+		$relativePath = \Test_Helper::invokePrivate($this->hasher, 'splitHash', array($hash));
+		$this->assertSame($expected, $relativePath);
+	}
+
+
+	/**
+	 * @dataProvider allHashProviders
+	 */
+	function testVerify($password, $hash, $expected) {
+		$this->config
+			->expects($this->any())
+			->method('getSystemValue')
+			->with('passwordsalt', null)
+			->will($this->returnValue('6Wow67q1wZQZpUUeI6G2LsWUu4XKx'));
+
+		$result = $this->hasher->verify($password, $hash);
+		$this->assertSame($expected, $result);
+	}
+
+}