Allow skipping redirects for extensions. (#308)

* Allow skipping redirects for extensions.

* Update docs/en/middleware.rst

Co-authored-by: Mark Story <mark@mark-story.com>

* Update tests/TestCase/Middleware/UnauthorizedHandler/RedirectHandlerTest.php

Co-authored-by: Mark Story <mark@mark-story.com>

* Update tests/TestCase/Middleware/UnauthorizedHandler/RedirectHandlerTest.php

Co-authored-by: Mark Story <mark@mark-story.com>

* Allow skipping redirects for extensions.

* Remove LogicException

- We can use one of the existing exceptions from the plugin.
- Expand test coverage to cover all the new branches

---------

Co-authored-by: Mark Story <mark@mark-story.com>

Author: dereuromark

docs/en/middleware.rst

@@ -198,6 +198,11 @@ Both redirect handlers share the same configuration options:
 * ``queryParam`` - the accessed request URL will be attached to the redirect URL
   query parameter (``redirect`` by default).
 * ``statusCode`` - HTTP status code of a redirect, ``302`` by default.
+* ``allowedRedirectExtensions`` - an array of allowed file extensions for redirecting.
+  If the request URL has a file extension that is not in this list, the redirect will not
+  happen and the exception will be rethrown. Can also be a boolean to toggle on/off
+  redirects entirely. This is useful to prevent unauthorized access to API based
+  responses, that should not be redirecting in any case. `true` by default and not enabled then.
 
 For example::
 
@@ -212,6 +217,7 @@ For example::
                 MissingIdentityException::class,
                 OtherException::class,
             ],
+            'allowedRedirectExtensions' => ['csv', 'pdf'],
         ],
     ]));
 

src/Middleware/UnauthorizedHandler/CakeRedirectHandler.php

@@ -41,6 +41,7 @@ class CakeRedirectHandler extends RedirectHandler
         ],
         'queryParam' => 'redirect',
         'statusCode' => 302,
+        'allowedRedirectExtensions' => true,
     ];
 
     /**

src/Middleware/UnauthorizedHandler/RedirectHandler.php

@@ -34,6 +34,8 @@ class RedirectHandler implements HandlerInterface
      *  - `url` - Url to redirect to.
      *  - `queryParam` - Query parameter name for the target url.
      *  - `statusCode` - Redirection status code.
+     *  - `allowedRedirectExtensions` - If true, redirects are allowed for all extensions.
+     *       Pass specific ones to allow list, or false to disallow redirects for any extension.
      *
      * @var array
      */
@@ -44,6 +46,7 @@ class RedirectHandler implements HandlerInterface
         'url' => '/login',
         'queryParam' => 'redirect',
         'statusCode' => 302,
+        'allowedRedirectExtensions' => true,
     ];
 
     /**
@@ -58,7 +61,7 @@ public function handle(
     ): ResponseInterface {
         $options += $this->defaultOptions;
 
-        if (!$this->checkException($exception, $options['exceptions'])) {
+        if (!$this->redirectAllowed($request, $options) || !$this->checkException($exception, $options['exceptions'])) {
             throw $exception;
         }
 
@@ -117,4 +120,28 @@ protected function getUrl(ServerRequestInterface $request, array $options): stri
 
         return $url;
     }
+
+    /**
+     * @param \Psr\Http\Message\ServerRequestInterface $request
+     * @param array $options
+     * @return bool
+     */
+    protected function redirectAllowed(ServerRequestInterface $request, array $options): bool
+    {
+        $extensions = $options['allowedRedirectExtensions'] ?? true;
+        if ($extensions === false) {
+            return false;
+        }
+        if ($extensions === true) {
+            return true;
+        }
+
+        /** @var \Cake\Http\ServerRequest $request */
+        $currentExtension = $request->getParam('_ext');
+        if (!$currentExtension) {
+            return true;
+        }
+
+        return in_array($currentExtension, (array)$extensions, true);
+    }
 }

tests/TestCase/Middleware/UnauthorizedHandler/RedirectHandlerTest.php

@@ -17,10 +17,12 @@
 namespace Authorization\Test\TestCase\Middleware\UnauthorizedHandler;
 
 use Authorization\Exception\Exception;
+use Authorization\Exception\MissingIdentityException;
 use Authorization\Middleware\UnauthorizedHandler\RedirectHandler;
 use Cake\Core\Configure;
 use Cake\Http\ServerRequestFactory;
 use Cake\TestSuite\TestCase;
+use LogicException;
 use PHPUnit\Framework\Attributes\DataProvider;
 
 class RedirectHandlerTest extends TestCase
@@ -160,4 +162,91 @@ public function testHandleException()
         $this->expectException(Exception::class);
         $handler->handle($exception, $request);
     }
+
+    public function testHandleRedirectionWithExtensionsFalse(): void
+    {
+        $handler = new RedirectHandler();
+
+        $exception = new MissingIdentityException();
+        $request = ServerRequestFactory::fromGlobals(
+            ['REQUEST_METHOD' => 'GET'],
+        );
+        $request = $request->withParam('_ext', 'csv');
+
+        $this->expectException(MissingIdentityException::class);
+
+        $handler->handle($exception, $request, [
+            'exceptions' => [
+                LogicException::class,
+            ],
+            'url' => '/users/login',
+            'allowedRedirectExtensions' => false,
+        ]);
+    }
+
+    public function testHandleRedirectionWithExtension(): void
+    {
+        $handler = new RedirectHandler();
+
+        $exception = new MissingIdentityException();
+        $request = ServerRequestFactory::fromGlobals(
+            ['REQUEST_METHOD' => 'GET'],
+        );
+        $request = $request->withParam('_ext', 'csv');
+
+        $this->expectException(MissingIdentityException::class);
+
+        $handler->handle($exception, $request, [
+            'exceptions' => [
+                MissingIdentityException::class,
+            ],
+            'url' => '/users/login',
+            'allowedRedirectExtensions' => [],
+        ]);
+    }
+
+    public function testHandleRedirectionWithExtensionAllowlisted(): void
+    {
+        $handler = new RedirectHandler();
+
+        $exception = new MissingIdentityException();
+        $request = ServerRequestFactory::fromGlobals(
+            ['REQUEST_METHOD' => 'GET'],
+        );
+        $request = $request->withParam('_ext', 'csv');
+
+        $response = $handler->handle($exception, $request, [
+            'exceptions' => [
+                Exception::class,
+            ],
+            'url' => '/users/login',
+            'queryParam' => null,
+            'allowedRedirectExtensions' => ['csv'],
+        ]);
+
+        $this->assertSame(302, $response->getStatusCode());
+        $this->assertSame('/users/login', $response->getHeaderLine('Location'));
+    }
+
+    public function testHandleRedirectionWithExtensionAllowedNoExtensionInRequest(): void
+    {
+        $handler = new RedirectHandler();
+
+        $exception = new Exception();
+        $request = ServerRequestFactory::fromGlobals(
+            ['REQUEST_METHOD' => 'GET'],
+        );
+
+        $response = $handler->handle($exception, $request, [
+            'exceptions' => [
+                Exception::class,
+            ],
+            'url' => '/users/login',
+            'queryParam' => null,
+            'allowedRedirectExtensions' => ['csv'],
+        ]);
+
+        $this->assertSame(302, $response->getStatusCode());
+        $this->assertSame('/users/login', $response->getHeaderLine('Location'));
+    }
 }