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<?php
/**
* @copyright Copyright (c) 2016, ownCloud, Inc.
*
* @author Arthur Schiwon <blizzz@arthur-schiwon.de>
* @author Bart Visscher <bartv@thisnet.nl>
* @author Bjoern Schiessle <bjoern@schiessle.org>
* @author Christoph Wurst <christoph@winzerhof-wurst.at>
* @author Jakob Sack <mail@jakobsack.de>
* @author Joas Schilling <coding@schilljs.com>
* @author Lukas Reschke <lukas@statuscode.ch>
* @author Markus Goetz <markus@woboq.com>
* @author Michael Gapczynski <GapczynskiM@gmail.com>
* @author Morris Jobke <hey@morrisjobke.de>
* @author Robin Appelman <robin@icewind.nl>
* @author Thomas Müller <thomas.mueller@tmit.eu>
* @author Vincent Petry <vincent@nextcloud.com>
*
* @license AGPL-3.0
*
* This code is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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, version 3,
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
*/
namespace OCA\DAV\Connector\Sabre;
use Exception;
use OC\Authentication\Exceptions\PasswordLoginForbiddenException;
use OC\Authentication\TwoFactorAuth\Manager;
use OC\Security\Bruteforce\Throttler;
use OC\User\Session;
use OCA\DAV\Connector\Sabre\Exception\PasswordLoginForbidden;
use OCP\IRequest;
use OCP\ISession;
use Psr\Log\LoggerInterface;
use Sabre\DAV\Auth\Backend\AbstractBasic;
use Sabre\DAV\Exception\NotAuthenticated;
use Sabre\DAV\Exception\ServiceUnavailable;
use Sabre\HTTP\RequestInterface;
use Sabre\HTTP\ResponseInterface;
class Auth extends AbstractBasic {
public const DAV_AUTHENTICATED = 'AUTHENTICATED_TO_DAV_BACKEND';
private ISession $session;
private Session $userSession;
private IRequest $request;
private ?string $currentUser = null;
private Manager $twoFactorManager;
private Throttler $throttler;
public function __construct(ISession $session,
Session $userSession,
IRequest $request,
Manager $twoFactorManager,
Throttler $throttler,
string $principalPrefix = 'principals/users/') {
$this->session = $session;
$this->userSession = $userSession;
$this->twoFactorManager = $twoFactorManager;
$this->request = $request;
$this->throttler = $throttler;
$this->principalPrefix = $principalPrefix;
// setup realm
$defaults = new \OCP\Defaults();
$this->realm = $defaults->getName();
}
/**
* Whether the user has initially authenticated via DAV
*
* This is required for WebDAV clients that resent the cookies even when the
* account was changed.
*
* @see https://github.com/owncloud/core/issues/13245
*/
public function isDavAuthenticated(string $username): bool {
return !is_null($this->session->get(self::DAV_AUTHENTICATED)) &&
$this->session->get(self::DAV_AUTHENTICATED) === $username;
}
/**
* Validates a username and password
*
* This method should return true or false depending on if login
* succeeded.
*
* @param string $username
* @param string $password
* @return bool
* @throws PasswordLoginForbidden
*/
protected function validateUserPass($username, $password) {
if ($this->userSession->isLoggedIn() &&
$this->isDavAuthenticated($this->userSession->getUser()->getUID())
) {
\OC_Util::setupFS($this->userSession->getUser()->getUID());
$this->session->close();
return true;
} else {
\OC_Util::setupFS(); //login hooks may need early access to the filesystem
try {
if ($this->userSession->logClientIn($username, $password, $this->request, $this->throttler)) {
\OC_Util::setupFS($this->userSession->getUser()->getUID());
$this->session->set(self::DAV_AUTHENTICATED, $this->userSession->getUser()->getUID());
$this->session->close();
return true;
} else {
$this->session->close();
return false;
}
} catch (PasswordLoginForbiddenException $ex) {
$this->session->close();
throw new PasswordLoginForbidden();
}
}
}
/**
* @return array{bool, string}
* @throws NotAuthenticated
* @throws ServiceUnavailable
*/
public function check(RequestInterface $request, ResponseInterface $response) {
try {
return $this->auth($request, $response);
} catch (NotAuthenticated $e) {
throw $e;
} catch (Exception $e) {
$class = get_class($e);
$msg = $e->getMessage();
\OC::$server->get(LoggerInterface::class)->error($e->getMessage(), ['exception' => $e]);
throw new ServiceUnavailable("$class: $msg");
}
}
/**
* Checks whether a CSRF check is required on the request
*/
private function requiresCSRFCheck(): bool {
// GET requires no check at all
if ($this->request->getMethod() === 'GET') {
return false;
}
// Official Nextcloud clients require no checks
if ($this->request->isUserAgent([
IRequest::USER_AGENT_CLIENT_DESKTOP,
IRequest::USER_AGENT_CLIENT_ANDROID,
IRequest::USER_AGENT_CLIENT_IOS,
])) {
return false;
}
// If not logged-in no check is required
if (!$this->userSession->isLoggedIn()) {
return false;
}
// POST always requires a check
if ($this->request->getMethod() === 'POST') {
return true;
}
// If logged-in AND DAV authenticated no check is required
if ($this->userSession->isLoggedIn() &&
$this->isDavAuthenticated($this->userSession->getUser()->getUID())) {
return false;
}
return true;
}
/**
* @return array{bool, string}
* @throws NotAuthenticated
*/
private function auth(RequestInterface $request, ResponseInterface $response): array {
$forcedLogout = false;
if (!$this->request->passesCSRFCheck() &&
$this->requiresCSRFCheck()) {
// In case of a fail with POST we need to recheck the credentials
if ($this->request->getMethod() === 'POST') {
$forcedLogout = true;
} else {
$response->setStatus(401);
throw new \Sabre\DAV\Exception\NotAuthenticated('CSRF check not passed.');
}
}
if ($forcedLogout) {
$this->userSession->logout();
} else {
if ($this->twoFactorManager->needsSecondFactor($this->userSession->getUser())) {
throw new \Sabre\DAV\Exception\NotAuthenticated('2FA challenge not passed.');
}
if (
//Fix for broken webdav clients
($this->userSession->isLoggedIn() && is_null($this->session->get(self::DAV_AUTHENTICATED))) ||
//Well behaved clients that only send the cookie are allowed
($this->userSession->isLoggedIn() && $this->session->get(self::DAV_AUTHENTICATED) === $this->userSession->getUser()->getUID() && $request->getHeader('Authorization') === null) ||
\OC_User::handleApacheAuth()
) {
$user = $this->userSession->getUser()->getUID();
$this->currentUser = $user;
$this->session->close();
return [true, $this->principalPrefix . $user];
}
}
if (!$this->userSession->isLoggedIn() && in_array('XMLHttpRequest', explode(',', $request->getHeader('X-Requested-With') ?? ''))) {
// do not re-authenticate over ajax, use dummy auth name to prevent browser popup
$response->addHeader('WWW-Authenticate','DummyBasic realm="' . $this->realm . '"');
$response->setStatus(401);
throw new \Sabre\DAV\Exception\NotAuthenticated('Cannot authenticate over ajax calls');
}
$data = parent::check($request, $response);
if ($data[0] === true) {
$startPos = strrpos($data[1], '/') + 1;
$user = $this->userSession->getUser()->getUID();
$data[1] = substr_replace($data[1], $user, $startPos);
}
return $data;
}
}
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