Merge pull request #35057 from nextcloud/enh/noid/rate-limit-public-share-endpoints

Add brute force protection on all methods wrapped by PublicShareMiddleware

lib/private/AppFramework/DependencyInjection/DIContainer.php

@@ -304,7 +304,8 @@ class DIContainer extends SimpleContainer implements IAppContainer {
 				new OC\AppFramework\Middleware\PublicShare\PublicShareMiddleware(
 					$c->get(IRequest::class),
 					$c->get(ISession::class),
-					$c->get(\OCP\IConfig::class)
+					$c->get(\OCP\IConfig::class),
+					$c->get(OC\Security\Bruteforce\Throttler::class)
 				)
 			);
 			$dispatcher->registerMiddleware(

lib/private/AppFramework/Middleware/PublicShare/PublicShareMiddleware.php

@@ -24,6 +24,7 @@
 namespace OC\AppFramework\Middleware\PublicShare;
 
 use OC\AppFramework\Middleware\PublicShare\Exceptions\NeedAuthenticationException;
+use OC\Security\Bruteforce\Throttler;
 use OCP\AppFramework\AuthPublicShareController;
 use OCP\AppFramework\Http\NotFoundResponse;
 use OCP\AppFramework\Middleware;
@@ -34,6 +35,7 @@ use OCP\IRequest;
 use OCP\ISession;
 
 class PublicShareMiddleware extends Middleware {
+
 	/** @var IRequest */
 	private $request;
 
@@ -43,10 +45,14 @@ class PublicShareMiddleware extends Middleware {
 	/** @var IConfig */
 	private $config;
 
-	public function __construct(IRequest $request, ISession $session, IConfig $config) {
+	/** @var Throttler */
+	private $throttler;
+
+	public function __construct(IRequest $request, ISession $session, IConfig $config, Throttler $throttler) {
 		$this->request = $request;
 		$this->session = $session;
 		$this->config = $config;
+		$this->throttler = $throttler;
 	}
 
 	public function beforeController($controller, $methodName) {
@@ -54,6 +60,11 @@ class PublicShareMiddleware extends Middleware {
 			return;
 		}
 
+		$controllerClassPath = explode('\\', get_class($controller));
+		$controllerShortClass = end($controllerClassPath);
+		$bruteforceProtectionAction = $controllerShortClass . '::' . $methodName;
+		$this->throttler->sleepDelayOrThrowOnMax($this->request->getRemoteAddress(), $bruteforceProtectionAction);
+
 		if (!$this->isLinkSharingEnabled()) {
 			throw new NotFoundException('Link sharing is disabled');
 		}
@@ -68,6 +79,8 @@ class PublicShareMiddleware extends Middleware {
 		$controller->setToken($token);
 
 		if (!$controller->isValidToken()) {
+			$this->throttle($bruteforceProtectionAction, $token);
+
 			$controller->shareNotFound();
 			throw new NotFoundException();
 		}
@@ -88,6 +101,7 @@ class PublicShareMiddleware extends Middleware {
 			throw new NeedAuthenticationException();
 		}
 
+		$this->throttle($bruteforceProtectionAction, $token);
 		throw new NotFoundException();
 	}
 
@@ -128,4 +142,10 @@ class PublicShareMiddleware extends Middleware {
 
 		return true;
 	}
+
+	private function throttle($bruteforceProtectionAction, $token): void {
+		$ip = $this->request->getRemoteAddress();
+		$this->throttler->sleepDelay($ip, $bruteforceProtectionAction);
+		$this->throttler->registerAttempt($bruteforceProtectionAction, $ip, ['token' => $token]);
+	}
 }

tests/lib/AppFramework/Middleware/PublicShare/PublicShareMiddlewareTest.php

@@ -25,6 +25,7 @@ namespace Test\AppFramework\Middleware\PublicShare;
 
 use OC\AppFramework\Middleware\PublicShare\Exceptions\NeedAuthenticationException;
 use OC\AppFramework\Middleware\PublicShare\PublicShareMiddleware;
+use OC\Security\Bruteforce\Throttler;
 use OCP\AppFramework\AuthPublicShareController;
 use OCP\AppFramework\Controller;
 use OCP\AppFramework\Http\NotFoundResponse;
@@ -44,6 +45,8 @@ class PublicShareMiddlewareTest extends \Test\TestCase {
 	private $session;
 	/** @var IConfig|\PHPUnit\Framework\MockObject\MockObject */
 	private $config;
+	/** @var IConfig|\PHPUnit\Framework\MockObject\MockObject */
+	private $throttler;
 
 	/** @var PublicShareMiddleware */
 	private $middleware;
@@ -55,11 +58,13 @@ class PublicShareMiddlewareTest extends \Test\TestCase {
 		$this->request = $this->createMock(IRequest::class);
 		$this->session = $this->createMock(ISession::class);
 		$this->config = $this->createMock(IConfig::class);
+		$this->throttler = $this->createMock(Throttler::class);
 
 		$this->middleware = new PublicShareMiddleware(
 			$this->request,
 			$this->session,
-			$this->config
+			$this->config,
+			$this->throttler
 		);
 	}