seemfoni

        $username = $request->request->get('username');
        $password = $request->request->get('password');

        if(is_null($username) || is_null($password)) {
            return new Response(
              'Please verify all your inputs.',
              Response::HTTP_UNAUTHORIZED,
              array('Content-type' => 'application/json')
            );
        }

        $user_manager = $this->get('fos_user.user_manager');
        $factory = $this->get('security.encoder_factory');

        $user = $user_manager->findUserByUsername($username);
        $encoder = $factory->getEncoder($user);
        $salt = $user->getSalt();

        if($encoder->isPasswordValid($user->getPassword(), $password, $salt)) {
            $response = new Response(
              'Welcome '. $user->getUsername(),
              Response::HTTP_OK,
              array('Content-type' => 'application/json')
            );
        } else {
            $response = new Response(
              'Username or Password not valid.',
              Response::HTTP_UNAUTHORIZED,
              array('Content-type' => 'application/json')
            );
        }