services/nextcloud/public.php

<?php

declare(strict_types=1);

use OC\ServiceUnavailableException;

/**
 * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
 * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
 * SPDX-License-Identifier: AGPL-3.0-only
 */

require_once __DIR__ . '/lib/versioncheck.php';

use OCP\App\IAppManager;
use OCP\IConfig;
use OCP\IRequest;
use OCP\Server;
use OCP\Template\ITemplateManager;
use OCP\Util;
use Psr\Log\LoggerInterface;

function resolveService(string $service): string {
	$services = [
		'webdav' => 'dav/appinfo/v1/publicwebdav.php',
		'dav' => 'dav/appinfo/v2/publicremote.php',
	];
	if (isset($services[$service])) {
		return $services[$service];
	}

	return Server::get(IConfig::class)->getAppValue('core', 'remote_' . $service);
}

try {
	require_once __DIR__ . '/lib/base.php';

	// All resources served via the DAV endpoint should have the strictest possible
	// policy. Exempted from this is the SabreDAV browser plugin which overwrites
	// this policy with a softer one if debug mode is enabled.
	header("Content-Security-Policy: default-src 'none';");

	// Check if Nextcloud is in maintenance mode
	if (Util::needUpgrade()) {
		// since the behavior of apps or remotes are unpredictable during
		// an upgrade, return a 503 directly
		throw new \Exception('Service unavailable', 503);
	}

	$request = Server::get(IRequest::class);
	$pathInfo = $request->getPathInfo();
	if ($pathInfo === false || $pathInfo === '') {
		throw new \Exception('Path not found', 404);
	}

	// Extract the service from the path
	if (!$pos = strpos($pathInfo, '/', 1)) {
		$pos = strlen($pathInfo);
	}
	$service = substr($pathInfo, 1, $pos - 1);

	// Resolve the service to a file
	$file = resolveService($service);
	if (!$file) {
		throw new \Exception('Path not found', 404);
	}

	// Extract the app from the service file
	$file = ltrim($file, '/');
	$parts = explode('/', $file, 2);
	$app = $parts[0];

	// Load all required applications
	$appManager = Server::get(IAppManager::class);
	\OC::$REQUESTEDAPP = $app;
	$appManager->loadApps(['authentication']);
	$appManager->loadApps(['extended_authentication']);
	$appManager->loadApps(['filesystem', 'logging']);

	// Check if the app is enabled
	if (!$appManager->isEnabledForUser($app)) {
		throw new \Exception('App not installed: ' . $app);
	}

	// Load the app
	$appManager->loadApp($app);
	OC_User::setIncognitoMode(true);

	$baseuri = OC::$WEBROOT . '/public.php/' . $service . '/';
	require_once $file;
} catch (Exception $ex) {
	$status = 500;
	if ($ex instanceof ServiceUnavailableException) {
		$status = 503;
	}
	//show the user a detailed error page
	Server::get(LoggerInterface::class)->error($ex->getMessage(), ['app' => 'public', 'exception' => $ex]);
	Server::get(ITemplateManager::class)->printExceptionErrorPage($ex, $status);
} catch (Error $ex) {
	//show the user a detailed error page
	Server::get(LoggerInterface::class)->error($ex->getMessage(), ['app' => 'public', 'exception' => $ex]);
	Server::get(ITemplateManager::class)->printExceptionErrorPage($ex, 500);
}