switch to registration via POST

- download relevant data is sent per POST, a token is received
- download is started by GET and the received token
- solves the disadvantages from XHR-only download
- job to cleanup download tokens

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

apps/files/appinfo/info.xml

@@ -26,6 +26,7 @@
 		<job>OCA\Files\BackgroundJob\ScanFiles</job>
 		<job>OCA\Files\BackgroundJob\DeleteOrphanedItems</job>
 		<job>OCA\Files\BackgroundJob\CleanupFileLocks</job>
+		<job>OCA\Files\BackgroundJob\CleanupDownloadTokens</job>
 		<job>OCA\Files\BackgroundJob\CleanupDirectEditingTokens</job>
 	</background-jobs>
 

apps/files/appinfo/routes.php

@@ -101,10 +101,15 @@
 				'url' => '/ajax/getstoragestats.php',
 				'verb' => 'GET',
 			],
+			[
+				'name' => 'ajax#registerDownload',
+				'url' => '/registerDownload',
+				'verb' => 'POST',
+			],
 			[
 				'name' => 'ajax#download',
 				'url' => '/ajax/download.php',
-				'verb' => 'POST',
+				'verb' => 'GET',
 			],
 			[
 				'name' => 'API#toggleShowFolder',

apps/files/lib/AppInfo/Application.php

@@ -68,6 +68,7 @@
 
 class Application extends App implements IBootstrap {
 	public const APP_ID = 'files';
+	public const DL_TOKEN_PREFIX = 'dlToken_';
 
 	public function __construct(array $urlParams = []) {
 		parent::__construct(self::APP_ID, $urlParams);

apps/files/lib/BackgroundJob/CleanupDownloadTokens.php

@@ -0,0 +1,60 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @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\lib\BackgroundJob;
+
+use OC\BackgroundJob\TimedJob;
+use OCA\Files\AppInfo\Application;
+use OCP\IConfig;
+
+class CleanupDownloadTokens extends TimedJob {
+	private const INTERVAL_MINUTES = 24 * 60;
+	/** @var IConfig */
+	private $config;
+
+	public function __construct(IConfig $config) {
+		$this->interval = self::INTERVAL_MINUTES;
+		$this->config = $config;
+	}
+
+	protected function run($argument) {
+		$appKeys = $this->config->getAppKeys(Application::APP_ID);
+		foreach ($appKeys as $key) {
+			if (strpos($key, Application::DL_TOKEN_PREFIX) !== 0) {
+				continue;
+			}
+			$dataStr = $this->config->getAppValue(Application::APP_ID, $key, '');
+			if ($dataStr === '') {
+				$this->config->deleteAppValue(Application::APP_ID, $key);
+				continue;
+			}
+			$data = \json_decode($dataStr, true);
+			if (!isset($data['lastActivity']) || (time() - $data['lastActivity']) > 24 * 60 * 2) {
+				// deletes tokens that have not seen activity for 2 days
+				// the period is chosen to allow continue of downloads with network interruptions in minde
+				$this->config->deleteAppValue(Application::APP_ID, $key);
+			}
+		}
+	}
+}

apps/files/lib/Controller/AjaxController.php

@@ -27,21 +27,40 @@
 namespace OCA\Files\Controller;
 
 use OC_Files;
+use OCA\Files\AppInfo\Application;
 use OCA\Files\Helper;
 use OCP\AppFramework\Controller;
 use OCP\AppFramework\Http\JSONResponse;
+use OCP\AppFramework\Http\NotFoundResponse;
 use OCP\Files\NotFoundException;
+use OCP\IConfig;
 use OCP\IRequest;
 use OCP\ISession;
+use OCP\Security\ISecureRandom;
+use function json_decode;
+use function json_encode;
 
 class AjaxController extends Controller {
 	/** @var ISession */
 	private $session;
+	/** @var IConfig */
+	private $config;
 
-	public function __construct(string $appName, IRequest $request, ISession $session) {
+	/** @var ISecureRandom */
+	private $secureRandom;
+
+	public function __construct(
+		string $appName,
+		IRequest $request,
+		ISession $session,
+		IConfig $config,
+		ISecureRandom $secureRandom
+	) {
 		parent::__construct($appName, $request);
 		$this->session = $session;
 		$this->request = $request;
+		$this->config = $config;
+		$this->secureRandom = $secureRandom;
 	}
 
 	/**
@@ -67,26 +86,62 @@ public function getStorageStats(string $dir = '/'): JSONResponse {
 	/**
 	 * @NoAdminRequired
 	 */
-	public function download($files, string $dir = '', string $downloadStartSecret = '') {
+	public function registerDownload($files, string $dir = '', string $downloadStartSecret = '') {
 		if (is_string($files)) {
 			$files = [$files];
 		} elseif (!is_array($files)) {
 			throw new \InvalidArgumentException('Invalid argument for files');
 		}
 
+		$attempts = 0;
+		do {
+			if ($attempts === 10) {
+				throw new \RuntimeException('Failed to create unique download token');
+			}
+			$token = $this->secureRandom->generate(15);
+			$attempts++;
+		} while ($this->config->getAppValue(Application::APP_ID, Application::DL_TOKEN_PREFIX . $token, '') !== '');
+
+		$this->config->setAppValue(
+			Application::APP_ID,
+			Application::DL_TOKEN_PREFIX . $token,
+			json_encode([
+				'files' => $files,
+				'dir' => $dir,
+				'downloadStartSecret' => $downloadStartSecret,
+				'lastActivity' => time()
+			])
+		);
+
+		return new JSONResponse(['token' => $token]);
+	}
+
+	/**
+	 * @NoAdminRequired
+	 * @NoCSRFRequired
+	 */
+	public function download(string $token) {
+		$dataStr = $this->config->getAppValue(Application::APP_ID, Application::DL_TOKEN_PREFIX . $token, '');
+		if ($dataStr === '') {
+			return new NotFoundResponse();
+		}
 		$this->session->close();
 
-		if (strlen($downloadStartSecret) <= 32
-			&& (preg_match('!^[a-zA-Z0-9]+$!', $downloadStartSecret) === 1)
+		$data = json_decode($dataStr, true);
+		$data['lastActivity'] = time();
+		$this->config->setAppValue(Application::APP_ID, Application::DL_TOKEN_PREFIX . $token, json_encode($data));
+
+		if (strlen($data['downloadStartSecret']) <= 32
+			&& (preg_match('!^[a-zA-Z0-9]+$!', $data['downloadStartSecret']) === 1)
 		) {
-			setcookie('ocDownloadStarted', $downloadStartSecret, time() + 20, '/');
+			setcookie('ocDownloadStarted', $data['downloadStartSecret'], time() + 20, '/');
 		}
 
 		$serverParams = [ 'head' => $this->request->getMethod() === 'HEAD' ];
 		if (isset($_SERVER['HTTP_RANGE'])) {
 			$serverParams['range'] = $this->request->getHeader('Range');
 		}
 
-		OC_Files::get($dir, $files, $serverParams);
+		OC_Files::get($data['dir'], $data['files'], $serverParams);
 	}
 }

apps/files/src/services/Download.js

@@ -20,32 +20,29 @@
  *
  */
 
-import fileDownload from 'js-file-download'
 import { generateUrl } from '@nextcloud/router'
 import axios from '@nextcloud/axios'
 
 export default class Download {
 
 	export
 	const
-	async get(files, dir, downloadStartSecret) {
-		await axios.post(
-			generateUrl('apps/files/ajax/download.php'),
+	get(files, dir, downloadStartSecret) {
+		axios.post(
+			generateUrl('apps/files/registerDownload'),
 			{
 				files,
 				dir,
 				downloadStartSecret,
-			},
-			{
-				responseType: 'blob',
 			}
 		).then(res => {
-			const fileNameMatch = res.headers['content-disposition'].match(/filename="(.+)"/)
-			let fileName = ''
-			if (fileNameMatch.length === 2) {
-				fileName = fileNameMatch[1]
+			if (res.status === 200 && res.data.token) {
+				const dlUrl = generateUrl(
+					'apps/files/ajax/download.php?token={token}',
+					{ token: res.data.token }
+				)
+				OC.redirect(dlUrl)
 			}
-			fileDownload(res.data, fileName)
 		})
 	}