Added CSRF Extender (#2095)

src/Extend/Csrf.php

@@ -0,0 +1,32 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Extend;
+
+use Flarum\Extension\Extension;
+use Illuminate\Contracts\Container\Container;
+
+class Csrf implements ExtenderInterface
+{
+    protected $csrfExemptPaths = [];
+
+    public function exemptPath(string $path)
+    {
+        $this->csrfExemptPaths[] = $path;
+
+        return $this;
+    }
+
+    public function extend(Container $container, Extension $extension = null)
+    {
+        $container->extend('flarum.http.csrfExemptPaths', function ($existingExemptPaths) {
+            return array_merge($existingExemptPaths, $this->csrfExemptPaths);
+        });
+    }
+}

src/Foundation/InstalledSite.php

@@ -21,6 +21,7 @@ use Flarum\Formatter\FormatterServiceProvider;
 use Flarum\Forum\ForumServiceProvider;
 use Flarum\Frontend\FrontendServiceProvider;
 use Flarum\Group\GroupServiceProvider;
+use Flarum\Http\HttpServiceProvider;
 use Flarum\Locale\LocaleServiceProvider;
 use Flarum\Mail\MailServiceProvider;
 use Flarum\Notification\NotificationServiceProvider;
@@ -125,6 +126,7 @@ class InstalledSite implements SiteInterface
         $laravel->register(FrontendServiceProvider::class);
         $laravel->register(GroupServiceProvider::class);
         $laravel->register(HashServiceProvider::class);
+        $laravel->register(HttpServiceProvider::class);
         $laravel->register(LocaleServiceProvider::class);
         $laravel->register(MailServiceProvider::class);
         $laravel->register(MigrationServiceProvider::class);

src/Http/HttpServiceProvider.php

@@ -0,0 +1,29 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Http;
+
+use Flarum\Foundation\AbstractServiceProvider;
+
+class HttpServiceProvider extends AbstractServiceProvider
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function register()
+    {
+        $this->app->singleton('flarum.http.csrfExemptPaths', function () {
+            return ['/api/token'];
+        });
+
+        $this->app->bind(Middleware\CheckCsrfToken::class, function ($app) {
+            return new Middleware\CheckCsrfToken($app->make('flarum.http.csrfExemptPaths'));
+        });
+    }
+}

src/Http/Middleware/CheckCsrfToken.php

@@ -17,8 +17,22 @@ use Psr\Http\Server\RequestHandlerInterface as Handler;
 
 class CheckCsrfToken implements Middleware
 {
+    protected $exemptRoutes;
+
+    public function __construct(array $exemptRoutes)
+    {
+        $this->exemptRoutes = $exemptRoutes;
+    }
+
     public function process(Request $request, Handler $handler): Response
     {
+        $path = $request->getAttribute('originalUri')->getPath();
+        foreach ($this->exemptRoutes as $exemptRoute) {
+            if (fnmatch($exemptRoute, $path)) {
+                return $handler->handle($request);
+            }
+        }
+
         if (in_array($request->getMethod(), ['GET', 'HEAD', 'OPTIONS'])) {
             return $handler->handle($request);
         }

tests/integration/api/authentication/WithTokenTest.php

@@ -43,7 +43,7 @@ class WithTokenTest extends TestCase
                         'password' => 'too-obscure'
                     ],
                 ]
-            )->withAttribute('bypassCsrfToken', true)
+            )
         );
 
         $this->assertEquals(200, $response->getStatusCode());
@@ -75,7 +75,7 @@ class WithTokenTest extends TestCase
                         'password' => 'too-incorrect'
                     ],
                 ]
-            )->withAttribute('bypassCsrfToken', true)
+            )
         );
 
         // HTTP 401 signals an authentication problem

tests/integration/extenders/CsrfTest.php

@@ -0,0 +1,114 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Tests\integration\extenders;
+
+use Flarum\Extend;
+use Flarum\Tests\integration\TestCase;
+use Flarum\User\User;
+
+class CsrfTest extends TestCase
+{
+    protected $testUser = [
+        'username' => 'test',
+        'password' => 'too-obscure',
+        'email' => 'test@machine.local',
+    ];
+
+    protected function prepDb()
+    {
+        $this->prepareDatabase([
+            'users' => [],
+        ]);
+    }
+
+    /**
+     * @test
+     */
+    public function create_user_post_needs_csrf_token_by_default()
+    {
+        $this->prepDb();
+
+        $response = $this->send(
+            $this->request('POST', '/api/users', [
+                'json' => [
+                    'data' => [
+                        'attributes' => $this->testUser
+                    ]
+                ],
+            ])
+        );
+
+        $this->assertEquals(400, $response->getStatusCode());
+    }
+
+    /**
+     * @test
+     */
+    public function create_user_post_doesnt_need_csrf_token_if_whitelisted()
+    {
+        $this->extend(
+            (new Extend\Csrf)
+                ->exemptPath('/api/users')
+        );
+
+        $this->prepDb();
+
+        $response = $this->send(
+            $this->request('POST', '/api/users', [
+                'json' => [
+                    'data' => [
+                        'attributes' => $this->testUser
+                    ]
+                ],
+            ])
+        );
+
+        $this->assertEquals(201, $response->getStatusCode());
+
+        $user = User::where('username', $this->testUser['username'])->firstOrFail();
+
+        $this->assertEquals(0, $user->is_email_confirmed);
+        $this->assertEquals($this->testUser['username'], $user->username);
+        $this->assertEquals($this->testUser['email'], $user->email);
+    }
+
+    /**
+     * @test
+     */
+    public function post_to_unknown_route_will_cause_400_error_without_csrf_override()
+    {
+        $this->prepDb();
+
+        $response = $this->send(
+            $this->request('POST', '/api/fake/route/i/made/up')
+        );
+
+        $this->assertEquals(400, $response->getStatusCode());
+    }
+
+    /**
+     * @test
+     */
+    public function csrf_matches_wildcards_properly()
+    {
+        $this->extend(
+            (new Extend\Csrf)
+                ->exemptPath('/api/fake/*/up')
+        );
+
+        $this->prepDb();
+
+        $response = $this->send(
+            $this->request('POST', '/api/fake/route/i/made/up')
+        );
+
+        $this->assertEquals(404, $response->getStatusCode());
+    }
+}