Telekom bearer token: handling

lib/MagentaBearer/InvalidTokenException.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace OCA\UserOIDC\MagentaBearer;
+
+use Exception;
+
+class InvalidTokenException extends Exception {
+}

lib/MagentaBearer/MBackend.php

@@ -0,0 +1,193 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2020, Roeland Jago Douma <[email protected]>
+ *
+ * @author Roeland Jago Douma <[email protected]>
+ *
+ * @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\UserOIDC\MagentaBearer;
+
+use OCA\UserOIDC\User\AbstractOidcBackend;
+use OCA\UserOIDC\Db\Provider;
+use OCA\UserOIDC\Event\TokenValidatedEvent;
+use OCA\UserOIDC\Service\DiscoveryService;
+use OCA\UserOIDC\Service\ProviderService;
+use OCA\UserOIDC\Service\ProvisioningEventService;
+use OCA\UserOIDC\AppInfo\Application;
+use OCA\UserOIDC\Db\ProviderMapper;
+use OCA\UserOIDC\Db\UserMapper;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\IConfig;
+use OCP\IRequest;
+use OCP\ISession;
+use OCP\IURLGenerator;
+use OCP\IUserManager;
+use OCP\Security\ICrypto;
+use Psr\Log\LoggerInterface;
+
+class MBackend extends AbstractOidcBackend {
+
+	/**
+	 * @var TokenService
+	 */
+	protected $mtokenService;
+
+	/**
+	 * @var ProvisioningEventService
+	 */
+	protected $provisioningService;
+
+	public function __construct(IConfig $config,
+								UserMapper $userMapper,
+								LoggerInterface $logger,
+								IRequest $request,
+								ISession $session,
+								IURLGenerator $urlGenerator,
+								IEventDispatcher $eventDispatcher,
+								DiscoveryService $discoveryService,
+								ProviderMapper $providerMapper,
+								ProviderService $providerService,
+								IUserManager $userManager,
+								ICrypto $crypto,
+								TokenService $mtokenService,
+								ProvisioningEventService $provisioningService
+								) {
+		parent::__construct($config, $userMapper, $logger, $request, $session,
+							$urlGenerator, $eventDispatcher, $discoveryService,
+							$providerMapper, $providerService, $userManager);
+
+		$this->mtokenService = $mtokenService;
+		$this->provisioningService = $provisioningService;
+		$this->crypto = $crypto;
+	}
+
+	public function getBackendName(): string {
+		return Application::APP_ID . "\\MagentaBearer";
+	}
+
+	/**
+	 * Backend is activated if header bearer token is detected.
+	 *
+	 * @return bool ture if bearer header found
+	 */
+	public function isSessionActive(): bool {
+		// if this returns true, getCurrentUserId is called
+		// not sure if we should rather to the validation in here as otherwise it might fail for other backends or bave other side effects
+		$headerToken = $this->request->getHeader(Application::OIDC_API_REQ_HEADER);
+		// session is active if we have a bearer token (API request) OR if we logged in via user_oidc (we have a provider ID in the session)
+		return (preg_match('/^\s*bearer\s+/i', $headerToken) != false);
+	}
+
+	/**
+	 * Return the id of the current user
+	 * @return string
+	 */
+	public function getCurrentUserId(): string {
+		// get the bearer token from headers
+		$headerToken = $this->request->getHeader(Application::OIDC_API_REQ_HEADER);
+		$headerToken = preg_replace('/^bearer\s+/i', '', $headerToken);
+		if ($headerToken === '') {
+			$this->logger->debug('No Bearer token');
+			return '';
+		}
+
+		$providers = $this->providerMapper->getProviders();
+		if (count($providers) === 0) {
+			$this->logger->debug('no OIDC providers');
+			return '';
+		}
+
+		// we implement only Telekom behavior (which includes auto-provisioning)
+		// so we neglect switches from the upstream Nexrcloud oidc handling
+
+		// try to validate with all providers
+		foreach ($providers as $provider) {
+			if ($this->providerService->getSetting($provider->getId(), ProviderService::SETTING_CHECK_BEARER, '0') === '1') {
+				try {
+					$sharedSecret = $this->crypto->decrypt($provider->getBearerSecret());
+					$bearerToken = $this->mtokenService->decryptToken($headerToken, $sharedSecret);
+					$this->mtokenService->verifySignature($bearerToken, $sharedSecret);
+					$payload = $this->mtokenService->decode($bearerToken);
+					$this->mtokenService->verifyClaims($payload, ['http://auth.magentacloud.de']);
+				} catch (InvalidTokenException $eToken) {
+					// there is
+					$this->logger->debug('Invalid token:' . $eToken->getMessage(). ". Trying another provider.");
+					continue;
+				} catch (SignatureException $eSignature) {
+					// only the key seems not to fit, so try the next provider
+					$this->logger->debug($eSignature->getMessage() . ". Trying another provider.");
+					continue;
+				} catch (\Throwable $e) {
+					// there is
+					$this->logger->debug('General non matching provider problem:' . $e->getMessage());
+					continue;
+				}
+
+				$uidAttribute = $this->providerService->getSetting($provider->getId(), ProviderService::SETTING_MAPPING_UID, 'sub');
+				$userId = $payload->{$uidAttribute};
+				if ($userId === null) {
+					$this->logger->debug('No extractable user id, check mapping!');
+					return '';
+				}
+
+				// check bearercache here, not skipping validation for security reasons
+
+				// Telekom bearer does not support refersh_token, so the pupose of TokenValidatedEvent is not given,
+				// but could produce trouble if not send with the field, apart from performance aspects.
+				//
+				// $discovery = $this->discoveryService->obtainDiscovery($provider);
+				// $this->eventDispatcher->dispatchTyped(new TokenValidatedEvent(['token' => $payload], $provider, $discovery));
+
+				try {
+					$this->provisioningService->provisionUser($userId, $provider->getId(), $payload);
+					$this->checkFirstLogin($userId); // create the folders same as on web login
+					return $userId;
+				} catch (ProvisioningDeniedException $denied) {
+					$this->logger->error('Bearer token access denied: ' . $denied->getMessage());
+					return '';
+				}
+			}
+		}
+
+		$this->logger->debug('Could not find provider for token');
+		return '';
+	}
+
+	/**
+	 * FIXXME: send proper error status from BAckend errors
+	 *
+	 * This function sets an https status code here (early in the failing backend operation)
+	 * to pass on bearer errors cleanly with correct status code and a readable reason
+	 *
+	 * For this,  there is a "tricky" setting of a header needed to make it working in all
+	 * known situations, see
+	 * https://stackoverflow.com/questions/3258634/php-how-to-send-http-response-code
+	 */
+	// protected function sendHttpStatus(int $httpStatusCode, string $httpStatusMsg) {
+	// 	$phpSapiName    = substr(php_sapi_name(), 0, 3);
+	// 	if ($phpSapiName == 'cgi' || $phpSapiName == 'fpm') {
+	// 		header('Status: ' . $httpStatusCode . ' ' . $httpStatusMsg);
+	// 	} else {
+	// 		$protocol = isset($_SERVER['SERVER_PROTOCOL']) ? $_SERVER['SERVER_PROTOCOL'] : 'HTTP/1.0';
+	// 		header($protocol . ' ' . $httpStatusCode . ' ' . $httpStatusMsg);
+	// 	}
+	// }
+}

lib/MagentaBearer/SignatureException.php

@@ -0,0 +1,6 @@
+<?php
+
+namespace OCA\UserOIDC\MagentaBearer;
+
+class SignatureException extends InvalidTokenException {
+}