Symfony2 : how to check if an action is secured?

php, security, symfony

Solution

When Symfony2 processes a request it matches the url pattern with each firewall defined in `app/config/security.yml`. When url pattern matches with a pattern of the firewall Symfony2 creates some listener objects and call `handle` method of those objects. If any listener returns a `Response` object then the loop breaks and Symfony2 outputs the response. Authentication part is done in authentication listeners. They are created from config defined in matched firewall e.g `form_login`, `http_basic` etc. If user is not authenticated then authenticated listeners create a `RedirectResponse` object to redirect user to login page. For your case, you can cheat by creating a custom authentication listener and add it in your secured page firewall. Sample implementation would be following,

Create a `Token` class,

namespace Your\Namespace;

use Symfony\Component\Security\Core\Authentication\Token\AbstractToken;

class MyToken extends AbstractToken
{
    public function __construct(array $roles = array())
    {
        parent::__construct($roles);
    }

    public function getCredentials()
    {
        return '';
    }
}

Create a class that implements `AuthenticationProviderInterface`. For `form_login` listener it authenticates with the given `UserProvider`. In this case it will do nothing.

namespace Your\Namespace;

use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
use Symfony\Component\Security\Core\Authentication\Provider\AuthenticationProviderInterface;
use Acme\BaseBundle\Firewall\MyToken;

class MyAuthProvider implements AuthenticationProviderInterface
{

    public function authenticate(TokenInterface $token)
    {
        if (!$this->supports($token)) {
            return null;
        }

        throw new \Exception('you should not get here');
    }

    public function supports(TokenInterface $token)
    {
        return $token instanceof MyToken;
    }

Create an entry point class. The listener will create a `RedirectResponse` from this class.

namespace Your\Namespace;

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Security\Core\Exception\AuthenticationException;
use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;
use Symfony\Component\Security\Http\HttpUtils;


class MyAuthenticationEntryPoint implements AuthenticationEntryPointInterface
{
    private $httpUtils;
    private $redirectPath;

    public function __construct(HttpUtils $httpUtils, $redirectPath)
    {
        $this->httpUtils = $httpUtils;
        $this->redirectPath = $redirectPath;
    }

    /**
     * {@inheritdoc}
     */
    public function start(Request $request, AuthenticationException $authException = null)
    {
        //redirect action goes here
        return $this->httpUtils->createRedirectResponse($request, $this->redirectPath);
    }

Create a listener class. Here you will implement your redirection logic.

namespace Your\Namespace;

use Symfony\Component\Security\Http\Firewall\ListenerInterface;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\Security\Core\SecurityContextInterface;
use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;

class MyAuthenticationListener implements ListenerInterface
{
    private $securityContext;
    private $authenticationEntryPoint;


    public function __construct(SecurityContextInterface $securityContext, AuthenticationEntryPointInterface $authenticationEntryPoint)
    {
        $this->securityContext = $securityContext;
        $this->authenticationEntryPoint = $authenticationEntryPoint;
    }

    public function handle(GetResponseEvent $event)
    {
        $token = $this->securityContext->getToken();
        $request = $event->getRequest();
        if($token === null){
            return;
        }

        //add your logic
        $redirect = // boolean value based on your logic

        if($token->isAuthenticated() && $redirect){

            $response = $this->authenticationEntryPoint->start($request);
            $event->setResponse($response);
            return;
        }
    }

}

Create the services.

<?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <services>

        <service id="my_firewall.security.authentication.listener"
                 class="Your\Namespace\MyAuthenticationListener"
                 parent="security.authentication.listener.abstract"
                 abstract="true">
            <argument type="service" id="security.context" />
            <argument /> <!-- Entry Point -->
        </service>

        <service id="my_firewall.entry_point" class="Your\Namespace\MyAuthenticationEntryPoint" public="false" ></service>

        <service id="my_firewall.auth_provider" class="Your\Namespace\MyAuthProvider" public="false"></service>
    </services>

</container>

Register the listener. Create a folder named `Security/Factory` in your bundles `DependencyInjection` folder. Then create the factory class.

namespace Your\Bundle\DependencyInjection\Security\Factory;

use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Reference;
use Symfony\Component\DependencyInjection\DefinitionDecorator;
use Symfony\Component\DependencyInjection\Definition;
use Symfony\Bundle\SecurityBundle\DependencyInjection\Security\Factory\SecurityFactoryInterface;
use Symfony\Component\Config\Definition\Builder\NodeDefinition;

class MyFirewallFactory implements SecurityFactoryInterface
{

    public function create(ContainerBuilder $container, $id, $config, $userProvider, $defaultEntryPoint)
    {
        $provider = 'my_firewall.auth_provider.'.$id;
        $container->setDefinition($provider, new DefinitionDecorator('my_firewall.auth_provider'));

        // entry point
        $entryPointId = $this->createEntryPoint($container, $id, $config, $defaultEntryPoint);

        // listener
        $listenerId = 'my_firewall.security.authentication.listener'.$id;
        $listener = $container->setDefinition($listenerId, new DefinitionDecorator('my_firewall.security.authentication.listener'));
        $listener->replaceArgument(1, new Reference($entryPointId));
        return array($provider, $listenerId, $entryPointId);
    }

    public function getPosition()
    {
        return 'pre_auth';
    }

    public function getKey()
    {
        return 'my_firewall'; //the listener name
    }

    protected function getListenerId()
    {
        return 'my_firewall.security.authentication.listener';
    }

    public function addConfiguration(NodeDefinition $node)
    {
        $node
            ->children()
                ->scalarNode('redirect_path')->end()
            ->end()
            ;
    }

    protected function createEntryPoint($container, $id, $config, $defaultEntryPointId)
    {
        $entryPointId = 'my_firewall.entry_point'.$id;
        $container
            ->setDefinition($entryPointId, new DefinitionDecorator('my_firewall.entry_point'))
            ->addArgument(new Reference('security.http_utils'))
            ->addArgument($config['redirect_path'])
            ;
        return $entryPointId;
    }

}

Then in your `NamespaceBundle.php` of your bundle folder add the following code.

public function build(ContainerBuilder $builder){
    parent::build($builder);
    $extension = $builder->getExtension('security');
    $extension->addSecurityListenerFactory(new Security\Factory\MyFirewallFactory());
}

Authentication listener is created, phew :). Now in your `app/config/security.yml` do following.

api_area:
  pattern: ^/secured/
  provider: fos_userbundle
  form_login:
    check_path: /login_check
    login_path: /login
    csrf_provider: form.csrf_provider
  my_firewall:
    redirect_path: /beta
  logout: true
  anonymous: true

Problem

Original source