1 files changed, 137 insertions, 0 deletions
diff --git a/lib/private/AppFramework/Middleware/Security/BruteForceMiddleware.php b/lib/private/AppFramework/Middleware/Security/BruteForceMiddleware.php
new file mode 100644
index 00000000000..4b4425517e0
--- /dev/null
+++ b/lib/private/AppFramework/Middleware/Security/BruteForceMiddleware.php
@@ -0,0 +1,137 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2017 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\AppFramework\Middleware\Security;
+
+use OC\AppFramework\Utility\ControllerMethodReflector;
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\Attribute\BruteForceProtection;
+use OCP\AppFramework\Http\Response;
+use OCP\AppFramework\Http\TooManyRequestsResponse;
+use OCP\AppFramework\Middleware;
+use OCP\AppFramework\OCS\OCSException;
+use OCP\AppFramework\OCSController;
+use OCP\IRequest;
+use OCP\Security\Bruteforce\IThrottler;
+use OCP\Security\Bruteforce\MaxDelayReached;
+use Psr\Log\LoggerInterface;
+use ReflectionMethod;
+
+/**
+ * Class BruteForceMiddleware performs the bruteforce protection for controllers
+ * that are annotated with @BruteForceProtection(action=$action) whereas $action
+ * is the action that should be logged within the database.
+ *
+ * @package OC\AppFramework\Middleware\Security
+ */
+class BruteForceMiddleware extends Middleware {
+	private int $delaySlept = 0;
+
+	public function __construct(
+		protected ControllerMethodReflector $reflector,
+		protected IThrottler $throttler,
+		protected IRequest $request,
+		protected LoggerInterface $logger,
+	) {
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function beforeController($controller, $methodName) {
+		parent::beforeController($controller, $methodName);
+
+		if ($this->reflector->hasAnnotation('BruteForceProtection')) {
+			$action = $this->reflector->getAnnotationParameter('BruteForceProtection', 'action');
+			$this->delaySlept += $this->throttler->sleepDelayOrThrowOnMax($this->request->getRemoteAddress(), $action);
+		} else {
+			$reflectionMethod = new ReflectionMethod($controller, $methodName);
+			$attributes = $reflectionMethod->getAttributes(BruteForceProtection::class);
+
+			if (!empty($attributes)) {
+				$remoteAddress = $this->request->getRemoteAddress();
+
+				foreach ($attributes as $attribute) {
+					/** @var BruteForceProtection $protection */
+					$protection = $attribute->newInstance();
+					$action = $protection->getAction();
+					$this->delaySlept += $this->throttler->sleepDelayOrThrowOnMax($remoteAddress, $action);
+				}
+			}
+		}
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function afterController($controller, $methodName, Response $response) {
+		if ($response->isThrottled()) {
+			try {
+				if ($this->reflector->hasAnnotation('BruteForceProtection')) {
+					$action = $this->reflector->getAnnotationParameter('BruteForceProtection', 'action');
+					$ip = $this->request->getRemoteAddress();
+					$this->throttler->registerAttempt($action, $ip, $response->getThrottleMetadata());
+					$this->delaySlept += $this->throttler->sleepDelayOrThrowOnMax($ip, $action);
+				} else {
+					$reflectionMethod = new ReflectionMethod($controller, $methodName);
+					$attributes = $reflectionMethod->getAttributes(BruteForceProtection::class);
+
+					if (!empty($attributes)) {
+						$ip = $this->request->getRemoteAddress();
+						$metaData = $response->getThrottleMetadata();
+
+						foreach ($attributes as $attribute) {
+							/** @var BruteForceProtection $protection */
+							$protection = $attribute->newInstance();
+							$action = $protection->getAction();
+
+							if (!isset($metaData['action']) || $metaData['action'] === $action) {
+								$this->throttler->registerAttempt($action, $ip, $metaData);
+								$this->delaySlept += $this->throttler->sleepDelayOrThrowOnMax($ip, $action);
+							}
+						}
+					} else {
+						$this->logger->debug('Response for ' . get_class($controller) . '::' . $methodName . ' got bruteforce throttled but has no annotation nor attribute defined.');
+					}
+				}
+			} catch (MaxDelayReached $e) {
+				if ($controller instanceof OCSController) {
+					throw new OCSException($e->getMessage(), Http::STATUS_TOO_MANY_REQUESTS);
+				}
+
+				return new TooManyRequestsResponse();
+			}
+		}
+
+		if ($this->delaySlept) {
+			$response->addHeader('X-Nextcloud-Bruteforce-Throttled', $this->delaySlept . 'ms');
+		}
+
+		return parent::afterController($controller, $methodName, $response);
+	}
+
+	/**
+	 * @param Controller $controller
+	 * @param string $methodName
+	 * @param \Exception $exception
+	 * @throws \Exception
+	 * @return Response
+	 */
+	public function afterException($controller, $methodName, \Exception $exception): Response {
+		if ($exception instanceof MaxDelayReached) {
+			if ($controller instanceof OCSController) {
+				throw new OCSException($exception->getMessage(), Http::STATUS_TOO_MANY_REQUESTS);
+			}
+
+			return new TooManyRequestsResponse();
+		}
+
+		throw $exception;
+	}
+}