From 25a59c0dc088a402b14bd9b236be9e85960b3df2 Mon Sep 17 00:00:00 2001
From: Julien Veyssier <julien-nc@posteo.net>
Date: Mon, 12 Jun 2023 17:36:49 +0200
Subject: [PATCH] add bruteforce protection in OauthApiController

Signed-off-by: Julien Veyssier <julien-nc@posteo.net>
---
 .../lib/Controller/OauthApiController.php     | 22 ++++++++++++++-----
 .../Controller/OauthApiControllerTest.php     |  6 +++++
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/apps/oauth2/lib/Controller/OauthApiController.php b/apps/oauth2/lib/Controller/OauthApiController.php
index 0dcc2a2cf71..b412e456fa8 100644
--- a/apps/oauth2/lib/Controller/OauthApiController.php
+++ b/apps/oauth2/lib/Controller/OauthApiController.php
@@ -86,6 +86,7 @@ class OauthApiController extends Controller {
 	/**
 	 * @PublicPage
 	 * @NoCSRFRequired
+	 * @BruteForceProtection(action=oauth2GetToken)
 	 *
 	 * @param string $grant_type
 	 * @param string $code
@@ -98,9 +99,11 @@ class OauthApiController extends Controller {
 
 		// We only handle two types
 		if ($grant_type !== 'authorization_code' && $grant_type !== 'refresh_token') {
-			return new JSONResponse([
+			$response = new JSONResponse([
 				'error' => 'invalid_grant',
 			], Http::STATUS_BAD_REQUEST);
+			$response->throttle(['invalid_grant' => $grant_type]);
+			return $response;
 		}
 
 		// We handle the initial and refresh tokens the same way
@@ -111,17 +114,21 @@ class OauthApiController extends Controller {
 		try {
 			$accessToken = $this->accessTokenMapper->getByCode($code);
 		} catch (AccessTokenNotFoundException $e) {
-			return new JSONResponse([
+			$response = new JSONResponse([
 				'error' => 'invalid_request',
 			], Http::STATUS_BAD_REQUEST);
+			$response->throttle(['invalid_request' => 'token not found', 'code' => $code]);
+			return $response;
 		}
 
 		try {
 			$client = $this->clientMapper->getByUid($accessToken->getClientId());
 		} catch (ClientNotFoundException $e) {
-			return new JSONResponse([
+			$response = new JSONResponse([
 				'error' => 'invalid_request',
 			], Http::STATUS_BAD_REQUEST);
+			$response->throttle(['invalid_request' => 'client not found', 'client_id' => $accessToken->getClientId()]);
+			return $response;
 		}
 
 		if (isset($this->request->server['PHP_AUTH_USER'])) {
@@ -133,15 +140,18 @@ class OauthApiController extends Controller {
 			$storedClientSecret = $this->crypto->decrypt($client->getSecret());
 		} catch (\Exception $e) {
 			$this->logger->error('OAuth client secret decryption error', ['exception' => $e]);
+			// we don't throttle here because it might not be a bruteforce attack
 			return new JSONResponse([
 				'error' => 'invalid_client',
 			], Http::STATUS_BAD_REQUEST);
 		}
 		// The client id and secret must match. Else we don't provide an access token!
 		if ($client->getClientIdentifier() !== $client_id || $storedClientSecret !== $client_secret) {
-			return new JSONResponse([
+			$response = new JSONResponse([
 				'error' => 'invalid_client',
 			], Http::STATUS_BAD_REQUEST);
+			$response->throttle(['invalid_client' => 'client ID or secret does not match']);
+			return $response;
 		}
 
 		$decryptedToken = $this->crypto->decrypt($accessToken->getEncryptedToken(), $code);
@@ -154,9 +164,11 @@ class OauthApiController extends Controller {
 		} catch (InvalidTokenException $e) {
 			//We can't do anything...
 			$this->accessTokenMapper->delete($accessToken);
-			return new JSONResponse([
+			$response = new JSONResponse([
 				'error' => 'invalid_request',
 			], Http::STATUS_BAD_REQUEST);
+			$response->throttle(['invalid_request' => 'token is invalid']);
+			return $response;
 		}
 
 		// Rotate the apptoken (so the old one becomes invalid basically)
diff --git a/apps/oauth2/tests/Controller/OauthApiControllerTest.php b/apps/oauth2/tests/Controller/OauthApiControllerTest.php
index eb9311dbbc7..c65302532a9 100644
--- a/apps/oauth2/tests/Controller/OauthApiControllerTest.php
+++ b/apps/oauth2/tests/Controller/OauthApiControllerTest.php
@@ -104,6 +104,7 @@ class OauthApiControllerTest extends TestCase {
 		$expected = new JSONResponse([
 			'error' => 'invalid_grant',
 		], Http::STATUS_BAD_REQUEST);
+		$expected->throttle(['invalid_grant' => 'foo']);
 
 		$this->assertEquals($expected, $this->oauthApiController->getToken('foo', null, null, null, null));
 	}
@@ -112,6 +113,7 @@ class OauthApiControllerTest extends TestCase {
 		$expected = new JSONResponse([
 			'error' => 'invalid_request',
 		], Http::STATUS_BAD_REQUEST);
+		$expected->throttle(['invalid_request' => 'token not found', 'code' => 'invalidcode']);
 
 		$this->accessTokenMapper->method('getByCode')
 			->with('invalidcode')
@@ -124,6 +126,7 @@ class OauthApiControllerTest extends TestCase {
 		$expected = new JSONResponse([
 			'error' => 'invalid_request',
 		], Http::STATUS_BAD_REQUEST);
+		$expected->throttle(['invalid_request' => 'token not found', 'code' => 'invalidrefresh']);
 
 		$this->accessTokenMapper->method('getByCode')
 			->with('invalidrefresh')
@@ -136,6 +139,7 @@ class OauthApiControllerTest extends TestCase {
 		$expected = new JSONResponse([
 			'error' => 'invalid_request',
 		], Http::STATUS_BAD_REQUEST);
+		$expected->throttle(['invalid_request' => 'client not found', 'client_id' => 42]);
 
 		$accessToken = new AccessToken();
 		$accessToken->setClientId(42);
@@ -169,6 +173,7 @@ class OauthApiControllerTest extends TestCase {
 		$expected = new JSONResponse([
 			'error' => 'invalid_client',
 		], Http::STATUS_BAD_REQUEST);
+		$expected->throttle(['invalid_client' => 'client ID or secret does not match']);
 
 		$accessToken = new AccessToken();
 		$accessToken->setClientId(42);
@@ -191,6 +196,7 @@ class OauthApiControllerTest extends TestCase {
 		$expected = new JSONResponse([
 			'error' => 'invalid_request',
 		], Http::STATUS_BAD_REQUEST);
+		$expected->throttle(['invalid_request' => 'token is invalid']);
 
 		$accessToken = new AccessToken();
 		$accessToken->setClientId(42);
-- 
2.39.5