1 files changed, 135 insertions, 0 deletions
diff --git a/apps/files/lib/Controller/OpenLocalEditorController.php b/apps/files/lib/Controller/OpenLocalEditorController.php
new file mode 100644
index 00000000000..ff39c1fe0e7
--- /dev/null
+++ b/apps/files/lib/Controller/OpenLocalEditorController.php
@@ -0,0 +1,135 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2022 Joas Schilling <coding@schilljs.com>
+ *
+ * @author Joas Schilling <coding@schilljs.com>
+ *
+ * @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 OCA\Files\Controller;
+
+use OCA\Files\Db\OpenLocalEditor;
+use OCA\Files\Db\OpenLocalEditorMapper;
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\DataResponse;
+use OCP\AppFramework\OCSController;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\DB\Exception;
+use OCP\IRequest;
+use OCP\Security\ISecureRandom;
+use Psr\Log\LoggerInterface;
+
+class OpenLocalEditorController extends OCSController {
+	public const TOKEN_LENGTH = 128;
+	public const TOKEN_DURATION = 600; // 10 Minutes
+	public const TOKEN_RETRIES = 50;
+
+	protected ITimeFactory $timeFactory;
+	protected OpenLocalEditorMapper $mapper;
+	protected ISecureRandom $secureRandom;
+	protected LoggerInterface $logger;
+	protected ?string $userId;
+
+	public function __construct(
+		string $appName,
+		IRequest $request,
+		ITimeFactory $timeFactory,
+		OpenLocalEditorMapper $mapper,
+		ISecureRandom $secureRandom,
+		LoggerInterface $logger,
+		?string $userId
+	) {
+		parent::__construct($appName, $request);
+
+		$this->timeFactory = $timeFactory;
+		$this->mapper = $mapper;
+		$this->secureRandom = $secureRandom;
+		$this->logger = $logger;
+		$this->userId = $userId;
+	}
+
+	/**
+	 * @NoAdminRequired
+	 * @UserRateThrottle(limit=10, period=120)
+	 */
+	public function create(string $path): DataResponse {
+		$pathHash = sha1($path);
+
+		$entity = new OpenLocalEditor();
+		$entity->setUserId($this->userId);
+		$entity->setPathHash($pathHash);
+		$entity->setExpirationTime($this->timeFactory->getTime() + self::TOKEN_DURATION); // Expire in 10 minutes
+
+		for ($i = 1; $i <= self::TOKEN_RETRIES; $i++) {
+			$token = $this->secureRandom->generate(self::TOKEN_LENGTH, ISecureRandom::CHAR_ALPHANUMERIC);
+			$entity->setToken($token);
+
+			try {
+				$this->mapper->insert($entity);
+
+				return new DataResponse([
+					'userId' => $this->userId,
+					'pathHash' => $pathHash,
+					'expirationTime' => $entity->getExpirationTime(),
+					'token' => $entity->getToken(),
+				]);
+			} catch (Exception $e) {
+				if ($e->getCode() !== Exception::REASON_UNIQUE_CONSTRAINT_VIOLATION) {
+					// Only retry on unique constraint violation
+					throw $e;
+				}
+			}
+		}
+
+		$this->logger->error('Giving up after ' . self::TOKEN_RETRIES . ' retries to generate a unique local editor token for path hash: ' . $pathHash);
+		return new DataResponse([], Http::STATUS_INTERNAL_SERVER_ERROR);
+	}
+
+	/**
+	 * @NoAdminRequired
+	 * @BruteForceProtection(action=openLocalEditor)
+	 */
+	public function validate(string $path, string $token): DataResponse {
+		$pathHash = sha1($path);
+
+		try {
+			$entity = $this->mapper->verifyToken($this->userId, $pathHash, $token);
+		} catch (DoesNotExistException $e) {
+			$response = new DataResponse([], Http::STATUS_NOT_FOUND);
+			$response->throttle(['userId' => $this->userId, 'pathHash' => $pathHash]);
+			return $response;
+		}
+
+		if ($entity->getExpirationTime() <= $this->timeFactory->getTime()) {
+			$this->mapper->delete($entity);
+			return new DataResponse([], Http::STATUS_NOT_FOUND);
+		}
+
+		return new DataResponse([
+			'userId' => $this->userId,
+			'pathHash' => $pathHash,
+			'expirationTime' => $entity->getExpirationTime(),
+			'token' => $entity->getToken(),
+		]);
+	}
+
+}