Simple Symfony Auth example

Authenticator.php

<?php

namespace Acme\DemoBundle\Security;

use Symfony\Component\Security\Core\Authentication\SimpleFormAuthenticatorInterface;
use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
use Symfony\Component\Security\Core\Exception\AuthenticationException;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Security\Core\User\User;
use Symfony\Component\Security\Core\User\UserProviderInterface;
use Symfony\Component\Security\Core\User\UserInterface;
use Symfony\Component\Security\Core\Exception\UsernameNotFoundException;
use Symfony\Component\Security\Core\Exception\UnsupportedUserException;

class Authenticator implements SimpleFormAuthenticatorInterface, UserProviderInterface
{
    public function createToken(Request $request, $username, $password, $providerKey)
    {
        return new UsernamePasswordToken($username, $password, $providerKey);
    }

    public function authenticate(TokenInterface $token, UserProviderInterface $userProvider, $providerKey)
    {
        if ($token->getUsername() === 'foo' && $token->getCredentials() === 'bar') {
            $user = $userProvider->loadUserByUsername('foo');

            return new UsernamePasswordToken($user, 'bar', 'dummy', $user->getRoles());
        }

        throw new AuthenticationException('Invalid username or password');
    }

    public function supports(TokenInterface $token, $providerKey)
    {
        return $token instanceof UsernamePasswordToken && $token->getProviderKey() === $providerKey;
    }

    public function handleAuthenticationFailure(GetResponseEvent $event, AuthenticationException $exception)
    {
        $event->setResponse(new Response('FAIL', 400));
    }

    public function loadUserByUsername($username)
    {
        if ($username === 'foo') {
            return new User('foo', 'bar', array('ROLE_USER'));
        }

        throw new UsernameNotFoundException(sprintf('Username "%s" does not exist.', $username));
    }

    public function refreshUser(UserInterface $user)
    {
        if (!$user instanceof User) {
            throw new UnsupportedUserException(sprintf('Instances of "%s" are not supported.', get_class($user)));
        }

        return $this->loadUserByUsername($user->getUsername());
    }

    public function supportsClass($class)
    {
        return $class === 'Symfony\Component\Security\Core\User\User';
    }
}

Looks interesting! An implementation like this might start to make things more clear.

Thinking back to my original issue, I need to be able to pull in additional information beyond the user like what system they're logging into. That's probably in "createToken", eh?