Symfony 2.5 and FOSRestBundle: How to log in user - symfony

Question

I want to programmatically log in an user using the FOSRestBundle (I am not using FOSUserBundle). It seems to work, but when I logged in successfully and try to access an secured endpoint, Symfony throws an AccessDeniedException.
This is my security.yml:
security:
providers:
main:
entity:
class: DepartureMonitor\RestBundle\Entity\User
property: email
role_hierarchy:
ROLE_EDITOR: [ ROLE_USER ]
ROLE_VU_ADMIN: [ ROLE_EDITOR, ROLE_USER ]
ROLE_ADMIN: [ ROLE_VU_ADMIN ]
encoders:
DepartureMonitor\RestBundle\Entity\User:
algorithm: bcrypt
cost: 13
firewalls:
dev:
pattern: ^/(_(profiler|wdt)|css|images|js)/
security: false
rest:
pattern: ^/api
provider: main
anonymous: true
form_login:
login_path: login
check_path: login_check
logout: ~
access_control:
- { path: ^/api/users/login, roles: IS_AUTHENTICATED_ANONYMOUSLY }
- { path: ^/api/users/password, roles: IS_AUTHENTICATED_ANONYMOUSLY }
- { path: ^/api, roles: ROLE_USER }
In my UsersController I have the following action:
/**
* #Post("/users/login")
*/
public function loginAction(Request $request)
{
$em = $this->getDoctrine()->getManager();
$user = $em->getRepository('DepartureMonitorRestBundle:User')->findOneBy(array('email' => $request->request->get('username')));
if ($user instanceof User) {
$factory = $this->get('security.encoder_factory');
$encoder = $factory->getEncoder($user);
$pw = $encoder->encodePassword($request->request->get('password'), $user->getSalt());
if($pw === $user->getPassword()) {
$token = new UsernamePasswordToken($user, $pw, "main", $user->getRoles());
$this->get('security.context')->setToken($token);
$event = new \Symfony\Component\Security\Http\Event\InteractiveLoginEvent($request, $token);
$this->get('event_dispatcher')->dispatch('security.interactive_login', $event);
if(!($this->getUser() instanceof User)) {
return $this->view(array('code' => HttpStatusCode::NOT_FOUND, 'message' => $this->get('translator')->trans('error.messages.bad_credentials')), HttpStatusCode::NOT_FOUND);
}
$view = $this->view($user, HttpStatusCode::CREATED);
$view->setSerializationContext(SerializationContext::create()->setGroups(array('login')));
return $this->handleView($view);
}
}
return $this->view(array('code' => HttpStatusCode::NOT_FOUND, 'message' => $this->get('translator')->trans('error.messages.bad_credentials')), HttpStatusCode::NOT_FOUND);
}
I don't know what the problem here is.
Any help is very appreciated.