feat: Close sessions created for login flow v2

Sessions created during the login flow v2 should be short lived to not leave an unexpected opened session in the browser.

This commit add a property to the session object to track its origin, and will close it as soon as possible, i.e., on the first non public page request.

Signed-off-by: Louis Chemineau <[email protected]>

Author: artonge

core/Controller/ClientFlowLoginV2Controller.php

@@ -49,6 +49,8 @@
 class ClientFlowLoginV2Controller extends Controller {
 	public const TOKEN_NAME = 'client.flow.v2.login.token';
 	public const STATE_NAME = 'client.flow.v2.state.token';
+	// Denotes that the session was created for the login flow and should therefore be ephemeral.
+	public const EPHEMERAL_NAME = 'client.flow.v2.state.ephemeral';
 
 	private LoginFlowV2Service $loginFlowV2Service;
 	private IURLGenerator $urlGenerator;

lib/composer/composer/autoload_classmap.php

@@ -686,6 +686,7 @@
     'OC\\AppFramework\\Logger' => $baseDir . '/lib/private/AppFramework/Logger.php',
     'OC\\AppFramework\\Middleware\\AdditionalScriptsMiddleware' => $baseDir . '/lib/private/AppFramework/Middleware/AdditionalScriptsMiddleware.php',
     'OC\\AppFramework\\Middleware\\CompressionMiddleware' => $baseDir . '/lib/private/AppFramework/Middleware/CompressionMiddleware.php',
+    'OC\\AppFramework\\Middleware\\FlowV2EphemeralSessionsMiddleware' => $baseDir . '/lib/private/AppFramework/Middleware/FlowV2EphemeralSessionsMiddleware.php',
     'OC\\AppFramework\\Middleware\\MiddlewareDispatcher' => $baseDir . '/lib/private/AppFramework/Middleware/MiddlewareDispatcher.php',
     'OC\\AppFramework\\Middleware\\NotModifiedMiddleware' => $baseDir . '/lib/private/AppFramework/Middleware/NotModifiedMiddleware.php',
     'OC\\AppFramework\\Middleware\\OCSMiddleware' => $baseDir . '/lib/private/AppFramework/Middleware/OCSMiddleware.php',
@@ -779,6 +780,7 @@
     'OC\\Authentication\\Login\\CreateSessionTokenCommand' => $baseDir . '/lib/private/Authentication/Login/CreateSessionTokenCommand.php',
     'OC\\Authentication\\Login\\EmailLoginCommand' => $baseDir . '/lib/private/Authentication/Login/EmailLoginCommand.php',
     'OC\\Authentication\\Login\\FinishRememberedLoginCommand' => $baseDir . '/lib/private/Authentication/Login/FinishRememberedLoginCommand.php',
+    'OC\\Authentication\\Login\\FlowV2EphemeralSessionsCommand' => $baseDir . '/lib/private/Authentication/Login/FlowV2EphemeralSessionsCommand.php',
     'OC\\Authentication\\Login\\LoggedInCheckCommand' => $baseDir . '/lib/private/Authentication/Login/LoggedInCheckCommand.php',
     'OC\\Authentication\\Login\\LoginData' => $baseDir . '/lib/private/Authentication/Login/LoginData.php',
     'OC\\Authentication\\Login\\LoginResult' => $baseDir . '/lib/private/Authentication/Login/LoginResult.php',

lib/composer/composer/autoload_static.php

@@ -719,6 +719,7 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OC\\AppFramework\\Logger' => __DIR__ . '/../../..' . '/lib/private/AppFramework/Logger.php',
         'OC\\AppFramework\\Middleware\\AdditionalScriptsMiddleware' => __DIR__ . '/../../..' . '/lib/private/AppFramework/Middleware/AdditionalScriptsMiddleware.php',
         'OC\\AppFramework\\Middleware\\CompressionMiddleware' => __DIR__ . '/../../..' . '/lib/private/AppFramework/Middleware/CompressionMiddleware.php',
+        'OC\\AppFramework\\Middleware\\FlowV2EphemeralSessionsMiddleware' => __DIR__ . '/../../..' . '/lib/private/AppFramework/Middleware/FlowV2EphemeralSessionsMiddleware.php',
         'OC\\AppFramework\\Middleware\\MiddlewareDispatcher' => __DIR__ . '/../../..' . '/lib/private/AppFramework/Middleware/MiddlewareDispatcher.php',
         'OC\\AppFramework\\Middleware\\NotModifiedMiddleware' => __DIR__ . '/../../..' . '/lib/private/AppFramework/Middleware/NotModifiedMiddleware.php',
         'OC\\AppFramework\\Middleware\\OCSMiddleware' => __DIR__ . '/../../..' . '/lib/private/AppFramework/Middleware/OCSMiddleware.php',
@@ -812,6 +813,7 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OC\\Authentication\\Login\\CreateSessionTokenCommand' => __DIR__ . '/../../..' . '/lib/private/Authentication/Login/CreateSessionTokenCommand.php',
         'OC\\Authentication\\Login\\EmailLoginCommand' => __DIR__ . '/../../..' . '/lib/private/Authentication/Login/EmailLoginCommand.php',
         'OC\\Authentication\\Login\\FinishRememberedLoginCommand' => __DIR__ . '/../../..' . '/lib/private/Authentication/Login/FinishRememberedLoginCommand.php',
+        'OC\\Authentication\\Login\\FlowV2EphemeralSessionsCommand' => __DIR__ . '/../../..' . '/lib/private/Authentication/Login/FlowV2EphemeralSessionsCommand.php',
         'OC\\Authentication\\Login\\LoggedInCheckCommand' => __DIR__ . '/../../..' . '/lib/private/Authentication/Login/LoggedInCheckCommand.php',
         'OC\\Authentication\\Login\\LoginData' => __DIR__ . '/../../..' . '/lib/private/Authentication/Login/LoginData.php',
         'OC\\Authentication\\Login\\LoginResult' => __DIR__ . '/../../..' . '/lib/private/Authentication/Login/LoginResult.php',

lib/private/AppFramework/DependencyInjection/DIContainer.php

@@ -37,6 +37,7 @@
 use OC\AppFramework\Http;
 use OC\AppFramework\Http\Dispatcher;
 use OC\AppFramework\Http\Output;
+use OC\AppFramework\Middleware\FlowV2EphemeralSessionsMiddleware;
 use OC\AppFramework\Middleware\MiddlewareDispatcher;
 use OC\AppFramework\Middleware\OCSMiddleware;
 use OC\AppFramework\Middleware\Security\CORSMiddleware;
@@ -236,7 +237,12 @@ public function __construct($appName, $urlParams = [], ServerContainer $server =
 				)
 			);
 
-
+			$dispatcher->registerMiddleware(
+				new FlowV2EphemeralSessionsMiddleware(
+					$c->get(ISession::class),
+					$c->get(IUserSession::class),
+				)
+			);
 
 			$securityMiddleware = new SecurityMiddleware(
 				$c->get(IRequest::class),

lib/private/AppFramework/Middleware/FlowV2EphemeralSessionsMiddleware.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\AppFramework\Middleware;
+
+use OC\Core\Controller\ClientFlowLoginV2Controller;
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Middleware;
+use OCP\ISession;
+use OCP\IUserSession;
+use ReflectionMethod;
+
+// Will close the session if the user session is ephemeral.
+// Happens when the user logs in via the login flow v2.
+class FlowV2EphemeralSessionsMiddleware extends Middleware {
+	public function __construct(
+		private ISession $session,
+		private IUserSession $userSession,
+	) {
+	}
+
+	public function beforeController(Controller $controller, string $methodName) {
+		if (!$this->session->get(ClientFlowLoginV2Controller::EPHEMERAL_NAME)) {
+			return;
+		}
+
+		if (
+			$controller instanceof ClientFlowLoginV2Controller &&
+			($methodName === 'grantPage' || $methodName === 'generateAppPassword')
+		) {
+			return;
+		}
+
+		$reflectionMethod = new ReflectionMethod($controller, $methodName);
+		if (!empty($reflectionMethod->getAttributes('PublicPage'))) {
+			return;
+		}
+
+		$this->userSession->logout();
+		$this->session->close();
+	}
+}

lib/private/Authentication/Login/Chain.php

@@ -63,6 +63,9 @@ class Chain {
 	/** @var FinishRememberedLoginCommand */
 	private $finishRememberedLoginCommand;
 
+	/** @var FlowV2EphemeralSessionsCommand */
+	private $flowV2EphemeralSessionsCommand;
+
 	public function __construct(PreLoginHookCommand $preLoginHookCommand,
 								UserDisabledCheckCommand $userDisabledCheckCommand,
 								UidLoginCommand $uidLoginCommand,
@@ -98,6 +101,7 @@ public function process(LoginData $loginData): LoginResult {
 			->setNext($this->emailLoginCommand)
 			->setNext($this->loggedInCheckCommand)
 			->setNext($this->completeLoginCommand)
+			->setNext($this->flowV2EphemeralSessionsCommand)
 			->setNext($this->createSessionTokenCommand)
 			->setNext($this->clearLostPasswordTokensCommand)
 			->setNext($this->updateLastPasswordConfirmCommand)

lib/private/Authentication/Login/FlowV2EphemeralSessionsCommand.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Authentication\Login;
+
+use OC\Core\Controller\ClientFlowLoginV2Controller;
+use OCP\ISession;
+
+class FlowV2EphemeralSessionsCommand extends ALoginCommand {
+	public function __construct(
+		private ISession $session,
+	) {
+	}
+
+	public function process(LoginData $loginData): LoginResult {
+		if (str_starts_with($loginData->getRedirectUrl() ?? '', '/login/v2/grant')) {
+			$this->session->set(ClientFlowLoginV2Controller::EPHEMERAL_NAME, true);
+		}
+
+		return $this->processNextOrFinishSuccessfully($loginData);
+	}
+}