Use CSP nonces

apps/theming/appinfo/app.php

@@ -47,6 +47,7 @@
 	'script',
 	[
 		'src' => $linkToJs,
+		'nonce' => \OC::$server->getContentSecurityPolicyNonceManager()->getNonce()
 	], ''
 );
 

core/templates/layout.base.php

@@ -19,7 +19,7 @@
 			<link rel="stylesheet" href="<?php print_unescaped($cssfile); ?>" media="print">
 		<?php endforeach; ?>
 		<?php foreach ($_['jsfiles'] as $jsfile): ?>
-			<script src="<?php print_unescaped($jsfile); ?>"></script>
+			<script nonce="<?php p(\OC::$server->getContentSecurityPolicyNonceManager()->getNonce()) ?>" src="<?php print_unescaped($jsfile); ?>"></script>
 		<?php endforeach; ?>
 		<?php print_unescaped($_['headers']); ?>
 	</head>

core/templates/layout.guest.php

@@ -20,7 +20,7 @@
 			<link rel="stylesheet" href="<?php print_unescaped($cssfile); ?>" media="print">
 		<?php endforeach; ?>
 		<?php foreach($_['jsfiles'] as $jsfile): ?>
-			<script src="<?php print_unescaped($jsfile); ?>"></script>
+			<script nonce="<?php p(\OC::$server->getContentSecurityPolicyNonceManager()->getNonce()) ?>" src="<?php print_unescaped($jsfile); ?>"></script>
 		<?php endforeach; ?>
 		<?php print_unescaped($_['headers']); ?>
 	</head>

core/templates/layout.user.php

@@ -27,7 +27,7 @@
 			<link rel="stylesheet" href="<?php print_unescaped($cssfile); ?>" media="print">
 		<?php endforeach; ?>
 		<?php foreach($_['jsfiles'] as $jsfile): ?>
-			<script src="<?php print_unescaped($jsfile); ?>"></script>
+			<script nonce="<?php p(\OC::$server->getContentSecurityPolicyNonceManager()->getNonce()) ?>" src="<?php print_unescaped($jsfile); ?>"></script>
 		<?php endforeach; ?>
 		<?php print_unescaped($_['headers']); ?>
 	</head>

lib/composer/composer/autoload_classmap.php

@@ -674,6 +674,7 @@
     'OC\\Security\\Bruteforce\\Throttler' => $baseDir . '/lib/private/Security/Bruteforce/Throttler.php',
     'OC\\Security\\CSP\\ContentSecurityPolicy' => $baseDir . '/lib/private/Security/CSP/ContentSecurityPolicy.php',
     'OC\\Security\\CSP\\ContentSecurityPolicyManager' => $baseDir . '/lib/private/Security/CSP/ContentSecurityPolicyManager.php',
+    'OC\\Security\\CSP\\ContentSecurityPolicyNonceManager' => $baseDir . '/lib/private/Security/CSP/ContentSecurityPolicyNonceManager.php',
     'OC\\Security\\CSRF\\CsrfToken' => $baseDir . '/lib/private/Security/CSRF/CsrfToken.php',
     'OC\\Security\\CSRF\\CsrfTokenGenerator' => $baseDir . '/lib/private/Security/CSRF/CsrfTokenGenerator.php',
     'OC\\Security\\CSRF\\CsrfTokenManager' => $baseDir . '/lib/private/Security/CSRF/CsrfTokenManager.php',

lib/composer/composer/autoload_static.php

@@ -704,6 +704,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Security\\Bruteforce\\Throttler' => __DIR__ . '/../../..' . '/lib/private/Security/Bruteforce/Throttler.php',
         'OC\\Security\\CSP\\ContentSecurityPolicy' => __DIR__ . '/../../..' . '/lib/private/Security/CSP/ContentSecurityPolicy.php',
         'OC\\Security\\CSP\\ContentSecurityPolicyManager' => __DIR__ . '/../../..' . '/lib/private/Security/CSP/ContentSecurityPolicyManager.php',
+        'OC\\Security\\CSP\\ContentSecurityPolicyNonceManager' => __DIR__ . '/../../..' . '/lib/private/Security/CSP/ContentSecurityPolicyNonceManager.php',
         'OC\\Security\\CSRF\\CsrfToken' => __DIR__ . '/../../..' . '/lib/private/Security/CSRF/CsrfToken.php',
         'OC\\Security\\CSRF\\CsrfTokenGenerator' => __DIR__ . '/../../..' . '/lib/private/Security/CSRF/CsrfTokenGenerator.php',
         'OC\\Security\\CSRF\\CsrfTokenManager' => __DIR__ . '/../../..' . '/lib/private/Security/CSRF/CsrfTokenManager.php',

lib/private/AppFramework/DependencyInjection/DIContainer.php

@@ -379,7 +379,8 @@ public function __construct($appName, $urlParams = array()){
 				$c['AppName'],
 				$app->isLoggedIn(),
 				$app->isAdminUser(),
-				$app->getServer()->getContentSecurityPolicyManager()
+				$app->getServer()->getContentSecurityPolicyManager(),
+				$app->getServer()->getCsrfTokenManager()
 			);
 		});
 

lib/private/AppFramework/Middleware/Security/SecurityMiddleware.php

@@ -36,6 +36,7 @@
 use OC\AppFramework\Middleware\Security\Exceptions\StrictCookieMissingException;
 use OC\AppFramework\Utility\ControllerMethodReflector;
 use OC\Security\CSP\ContentSecurityPolicyManager;
+use OC\Security\CSRF\CsrfTokenManager;
 use OCP\AppFramework\Http\ContentSecurityPolicy;
 use OCP\AppFramework\Http\EmptyContentSecurityPolicy;
 use OCP\AppFramework\Http\RedirectResponse;
@@ -77,6 +78,8 @@ class SecurityMiddleware extends Middleware {
 	private $isAdminUser;
 	/** @var ContentSecurityPolicyManager */
 	private $contentSecurityPolicyManager;
+	/** @var CsrfTokenManager */
+	private $csrfTokenManager;
 
 	/**
 	 * @param IRequest $request
@@ -88,6 +91,7 @@ class SecurityMiddleware extends Middleware {
 	 * @param bool $isLoggedIn
 	 * @param bool $isAdminUser
 	 * @param ContentSecurityPolicyManager $contentSecurityPolicyManager
+	 * @param CSRFTokenManager $csrfTokenManager
 	 */
 	public function __construct(IRequest $request,
 								ControllerMethodReflector $reflector,
@@ -97,7 +101,8 @@ public function __construct(IRequest $request,
 								$appName,
 								$isLoggedIn,
 								$isAdminUser,
-								ContentSecurityPolicyManager $contentSecurityPolicyManager) {
+								ContentSecurityPolicyManager $contentSecurityPolicyManager,
+								CsrfTokenManager $csrfTokenManager) {
 		$this->navigationManager = $navigationManager;
 		$this->request = $request;
 		$this->reflector = $reflector;
@@ -107,6 +112,7 @@ public function __construct(IRequest $request,
 		$this->isLoggedIn = $isLoggedIn;
 		$this->isAdminUser = $isAdminUser;
 		$this->contentSecurityPolicyManager = $contentSecurityPolicyManager;
+		$this->csrfTokenManager = $csrfTokenManager;
 	}
 
 
@@ -171,6 +177,23 @@ public function beforeController($controller, $methodName) {
 
 	}
 
+	private function browserSupportsCspV3() {
+		$browserWhitelist = [
+			// Chrome 40+
+			'/^Mozilla\/5\.0 \([^)]+\) AppleWebKit\/[0-9.]+ \(KHTML, like Gecko\) Chrome\/[4-9][0-9].[0-9.]+ (Mobile Safari|Safari)\/[0-9.]+$/',
+			// Firefox 45+
+			'/^Mozilla\/5\.0 \([^)]+\) Gecko\/[0-9.]+ Firefox\/(4[5-9]|[5-9][0-9])\.[0-9.]+$/',
+			// Safari 10+
+			'/^Mozilla\/5\.0 \([^)]+\) AppleWebKit\/[0-9.]+ \(KHTML, like Gecko\) Version\/1[0-9.]+ Safari\/[0-9.A-Z]+$/',
+		];
+
+		if($this->request->isUserAgent($browserWhitelist)) {
+			return true;
+		}
+
+		return false;
+	}
+
 	/**
 	 * Performs the default CSP modifications that may be injected by other
 	 * applications
@@ -190,6 +213,10 @@ public function afterController($controller, $methodName, Response $response) {
 		$defaultPolicy = $this->contentSecurityPolicyManager->getDefaultPolicy();
 		$defaultPolicy = $this->contentSecurityPolicyManager->mergePolicies($defaultPolicy, $policy);
 
+		if($this->browserSupportsCspV3()) {
+			$defaultPolicy->useJsNonce($this->csrfTokenManager->getToken()->getEncryptedValue());
+		}
+
 		$response->setContentSecurityPolicy($defaultPolicy);
 
 		return $response;

lib/private/Security/CSP/ContentSecurityPolicyNonceManager.php

@@ -0,0 +1,54 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 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\Security\CSP;
+
+use OC\Security\CSRF\CsrfTokenManager;
+
+/**
+ * @package OC\Security\CSP
+ */
+class ContentSecurityPolicyNonceManager {
+	/** @var CsrfTokenManager */
+	private $csrfTokenManager;
+	/** @var string */
+	private $nonce = '';
+
+	/**
+	 * @param CsrfTokenManager $csrfTokenManager
+	 */
+	public function __construct(CsrfTokenManager $csrfTokenManager) {
+		$this->csrfTokenManager = $csrfTokenManager;
+	}
+
+	/**
+	 * Returns the current CSP nounce
+	 *
+	 * @return string
+	 */
+	public function getNonce() {
+		if($this->nonce === '') {
+			$this->nonce = base64_encode($this->csrfTokenManager->getToken()->getEncryptedValue());
+		}
+
+		return $this->nonce;
+	}
+}

lib/private/Security/CSRF/CsrfToken.php

@@ -33,6 +33,8 @@
 class CsrfToken {
 	/** @var string */
 	private $value;
+	/** @var string */
+	private $encryptedValue = '';
 
 	/**
 	 * @param string $value Value of the token. Can be encrypted or not encrypted.
@@ -48,8 +50,12 @@ public function __construct($value) {
 	 * @return string
 	 */
 	public function getEncryptedValue() {
-		$sharedSecret = base64_encode(random_bytes(strlen($this->value)));
-		return base64_encode($this->value ^ $sharedSecret) .':'.$sharedSecret;
+		if($this->encryptedValue === '') {
+			$sharedSecret = base64_encode(random_bytes(strlen($this->value)));
+			$this->encryptedValue = base64_encode($this->value ^ $sharedSecret) . ':' . $sharedSecret;
+		}
+
+		return $this->encryptedValue;
 	}
 
 	/**

lib/private/Security/CSRF/CsrfTokenManager.php

@@ -34,6 +34,8 @@ class CsrfTokenManager {
 	private $tokenGenerator;
 	/** @var SessionStorage */
 	private $sessionStorage;
+	/** @var CsrfToken|null */
+	private $csrfToken = null;
 
 	/**
 	 * @param CsrfTokenGenerator $tokenGenerator
@@ -51,14 +53,19 @@ public function __construct(CsrfTokenGenerator $tokenGenerator,
 	 * @return CsrfToken
 	 */
 	public function getToken() {
+		if(!is_null($this->csrfToken)) {
+			return $this->csrfToken;
+		}
+
 		if($this->sessionStorage->hasToken()) {
 			$value = $this->sessionStorage->getToken();
 		} else {
 			$value = $this->tokenGenerator->generateToken();
 			$this->sessionStorage->setToken($value);
 		}
 
-		return new CsrfToken($value);
+		$this->csrfToken = new CsrfToken($value);
+		return $this->csrfToken;
 	}
 
 	/**
@@ -69,13 +76,15 @@ public function getToken() {
 	public function refreshToken() {
 		$value = $this->tokenGenerator->generateToken();
 		$this->sessionStorage->setToken($value);
-		return new CsrfToken($value);
+		$this->csrfToken = new CsrfToken($value);
+		return $this->csrfToken;
 	}
 
 	/**
 	 * Remove the current token from the storage.
 	 */
 	public function removeToken() {
+		$this->csrfToken = null;
 		$this->sessionStorage->removeToken();
 	}
 

lib/private/Server.php

@@ -73,6 +73,7 @@
 use OC\Security\CertificateManager;
 use OC\Security\CSP\ContentSecurityPolicyManager;
 use OC\Security\Crypto;
+use OC\Security\CSP\ContentSecurityPolicyNonceManager;
 use OC\Security\CSRF\CsrfTokenGenerator;
 use OC\Security\CSRF\CsrfTokenManager;
 use OC\Security\CSRF\TokenStorage\SessionStorage;
@@ -708,6 +709,11 @@ public function __construct($webRoot, \OC\Config $config) {
 		$this->registerService('ContentSecurityPolicyManager', function (Server $c) {
 			return new ContentSecurityPolicyManager();
 		});
+		$this->registerService('ContentSecurityPolicyNonceManager', function(Server $c) {
+			return new ContentSecurityPolicyNonceManager(
+				$c->getCsrfTokenManager()
+			);
+		});
 		$this->registerService('ShareManager', function(Server $c) {
 			$config = $c->getConfig();
 			$factoryClass = $config->getSystemValue('sharing.managerFactory', '\OC\Share20\ProviderFactory');
@@ -1405,6 +1411,13 @@ public function getContentSecurityPolicyManager() {
 		return $this->query('ContentSecurityPolicyManager');
 	}
 
+	/**
+	 * @return ContentSecurityPolicyNonceManager
+	 */
+	public function getContentSecurityPolicyNonceManager() {
+		return $this->query('ContentSecurityPolicyNonceManager');
+	}
+
 	/**
 	 * Not a public API as of 8.2, wait for 9.0
 	 *

lib/public/AppFramework/Http/ContentSecurityPolicy.php

@@ -24,8 +24,6 @@
 
 namespace OCP\AppFramework\Http;
 
-use OCP\AppFramework\Http;
-
 /**
  * Class ContentSecurityPolicy is a simple helper which allows applications to
  * modify the Content-Security-Policy sent by ownCloud. Per default only JavaScript,

lib/public/AppFramework/Http/EmptyContentSecurityPolicy.php

@@ -38,6 +38,8 @@
 class EmptyContentSecurityPolicy {
 	/** @var bool Whether inline JS snippets are allowed */
 	protected $inlineScriptAllowed = null;
+	/** @var string Whether JS nonces should be used */
+	protected $useJsNonce = null;
 	/**
 	 * @var bool Whether eval in JS scripts is allowed
 	 * TODO: Disallow per default
@@ -74,12 +76,25 @@ class EmptyContentSecurityPolicy {
 	 * @param bool $state
 	 * @return $this
 	 * @since 8.1.0
+	 * @deprecated 10.0 CSP tokens are now used
 	 */
 	public function allowInlineScript($state = false) {
 		$this->inlineScriptAllowed = $state;
 		return $this;
 	}
 
+	/**
+	 * Use the according JS nonce
+	 *
+	 * @param string $nonce
+	 * @return $this
+	 * @since 9.2.0
+	 */
+	public function useJsNonce($nonce) {
+		$this->useJsNonce = $nonce;
+		return $this;
+	}
+
 	/**
 	 * Whether eval in JavaScript is allowed or forbidden
 	 * @param bool $state
@@ -323,6 +338,15 @@ public function buildPolicy() {
 
 		if(!empty($this->allowedScriptDomains) || $this->inlineScriptAllowed || $this->evalScriptAllowed) {
 			$policy .= 'script-src ';
+			if(is_string($this->useJsNonce)) {
+				$policy .= '\'nonce-'.base64_encode($this->useJsNonce).'\'';
+				$allowedScriptDomains = array_flip($this->allowedScriptDomains);
+				unset($allowedScriptDomains['\'self\'']);
+				$this->allowedScriptDomains = array_flip($allowedScriptDomains);
+				if(count($allowedScriptDomains) !== 0) {
+					$policy .= ' ';
+				}
+			}
 			if(is_array($this->allowedScriptDomains)) {
 				$policy .= implode(' ', $this->allowedScriptDomains);
 			}

tests/lib/AppFramework/Http/EmptyContentSecurityPolicyTest.php

@@ -427,4 +427,28 @@ public function testGetPolicyDisallowChildSrcDomainMultipleStakes() {
 		$this->contentSecurityPolicy->disallowChildSrcDomain('www.owncloud.org')->disallowChildSrcDomain('www.owncloud.com');
 		$this->assertSame($expectedPolicy, $this->contentSecurityPolicy->buildPolicy());
 	}
+
+	public function testGetPolicyWithJsNonceAndScriptDomains() {
+		$expectedPolicy = "default-src 'none';script-src 'nonce-TXlKc05vbmNl' www.nextcloud.com www.nextcloud.org";
+
+		$this->contentSecurityPolicy->addAllowedScriptDomain('www.nextcloud.com');
+		$this->contentSecurityPolicy->useJsNonce('MyJsNonce');
+		$this->contentSecurityPolicy->addAllowedScriptDomain('www.nextcloud.org');
+		$this->assertSame($expectedPolicy, $this->contentSecurityPolicy->buildPolicy());
+	}
+
+	public function testGetPolicyWithJsNonceAndSelfScriptDomain() {
+		$expectedPolicy = "default-src 'none';script-src 'nonce-TXlKc05vbmNl'";
+
+		$this->contentSecurityPolicy->useJsNonce('MyJsNonce');
+		$this->contentSecurityPolicy->addAllowedScriptDomain("'self'");
+		$this->assertSame($expectedPolicy, $this->contentSecurityPolicy->buildPolicy());
+	}
+
+	public function testGetPolicyWithoutJsNonceAndSelfScriptDomain() {
+		$expectedPolicy = "default-src 'none';script-src 'self'";
+
+		$this->contentSecurityPolicy->addAllowedScriptDomain("'self'");
+		$this->assertSame($expectedPolicy, $this->contentSecurityPolicy->buildPolicy());
+	}
 }