CORS Middleware for Laravel

Implements https://github.com/asm89/stack-cors for Laravel

About

The laravel-cors package allows you to send Cross-Origin Resource Sharing headers with Laravel middleware configuration.

If you want to have a global overview of CORS workflow, you can browse this image.

Upgrading from 0.x / barryvdh-laravel-cors

When upgrading from 0.x versions, there are some breaking changes:

• A new 'paths' property is used to enable/disable CORS on certain routes. This is empty by default, so fill it correctly!
• Group middleware is no longer supported, use the global middleware
• The vendor name has changed (see installation/usage)
• The casing on the props in cors.php has changed from camelCase to snake_case, so if you already have a cors.php file you will need to update the props in there to match the new casing.

Features

• Handles CORS pre-flight OPTIONS requests
• Adds CORS headers to your responses
• Match routes to only add CORS to certain Requests

Installation

Require the fruitcake/laravel-cors package in your composer.json and update your dependencies:

composer require fruitcake/laravel-cors

If you get a conflict, this could be because an older version of barryvdh/laravel-cors or fruitcake/laravel-cors is installed. Remove the conflicting package first, then try install again:

composer remove barryvdh/laravel-cors fruitcake/laravel-cors
composer require fruitcake/laravel-cors

Global usage

To allow CORS for all your routes, add the HandleCors middleware at the top of the $middleware property of app/Http/Kernel.php class:

protected $middleware = [
  \Fruitcake\Cors\HandleCors::class,
    // ...
];

Now update the config to define the paths you want to run the CORS service on, (see Configuration below):

'paths' => ['api/*'],

Configuration

The defaults are set in config/cors.php. Publish the config to copy the file to your own config:

php artisan vendor:publish --tag="cors"

Note: When using custom headers, like X-Auth-Token or X-Requested-With, you must set the allowed_headers to include those headers. You can also set it to ['*'] to allow all custom headers.

Note: If you are explicitly whitelisting headers, you must include Origin or requests will fail to be recognized as CORS.

Options

allowed_origins, allowed_headers and allowed_methods can be set to ['*'] to accept any value.

Note: For allowed_origins you must include the scheme when not using a wildcard, eg. ['http://example.com', 'https://example.com']. You must also take into account that the scheme will be present when using allowed_origins_patterns.

Note: Try to be a specific as possible. You can start developing with loose constraints, but it's better to be as strict as possible!

Note: Because of http method overriding in Laravel, allowing POST methods will also enable the API users to perform PUT and DELETE requests as well.

Note: Sometimes it's necessary to specify the port (when you're coding your app in a local environment for example). You can specify the port or using a wildcard here too, eg. localhost:3000, localhost:* or even using a FQDN app.mydomain.com:8080

Lumen

On Lumen, just register the ServiceProvider manually in your bootstrap/app.php file:

$app->register(Fruitcake\Cors\CorsServiceProvider::class);

Also copy the cors.php config file to config/cors.php and put it into action:

$app->configure('cors');

Global usage for Lumen

To allow CORS for all your routes, add the HandleCors middleware to the global middleware and set the paths property in the config.

$app->middleware([
    // ...
    Fruitcake\Cors\HandleCors::class,
]);

Common problems

Wrong config

Make sure the path option in the config is correct and actually matches the route you are using. Remember to clear the config cache as well.

Error handling, Middleware order

Sometimes errors/middleware that return own responses can prevent the CORS Middleware from being run. Try changing the order of the Middleware and make sure it's the first entry in the global middleware, not a route group. Also check your logs for actual errors, because without CORS, the errors will be swallowed by the browser, only showing CORS errors. Also try running it without CORS to make sure it actually works.

Authorization headers / Credentials

If your Request includes an Authorization header or uses Credentials mode, set the supports_credentials value in the config to true. This will set the Access-Control-Allow-Credentials Header to true.

Echo/die

If you echo(), dd(), die(), exit(), dump() etc in your code, you will break the Middleware flow. When output is sent before headers, CORS cannot be added. When the scripts exits before the CORS middleware finished, CORS headers will not be added. Always return a proper response or throw an Exception.

Disabling CSRF protection for your API

If possible, use a route group with CSRF protection disabled. Otherwise you can disable CSRF for certain requests in App\Http\Middleware\VerifyCsrfToken:

protected $except = [
    'api/*',
    'sub.domain.zone' => [
      'prefix/*'
    ],
];

Duplicate headers

The CORS Middleware should be the only place you add these headers. If you also add headers in .htaccess, nginx or your index.php file, you will get duplicate headers and unexpected results.

License

Released under the MIT License, see LICENSE.