JwtAuth para Symfony usando características de PHP 5.5 o superior

JwtAuth.php

<?php 

namespace AppBundle\Services;

use Doctrine\ORM\EntityManagerInterface;
use Firebase\JWT\JWT;

class JwtAuth
{
    protected $em;
    protected $key;

    public function __construct(EntityManagerInterface $entityManager)
    {
        $this->em = $entityManager;
        $this->key = 'secret';
    }

    public function signup($email, $password, $getHash = null)
    {
        $user = $this->em->getRepository('BackendBundle:User')->findOneBy([
            'email'     => $email,
        ]);

        $signup = false;

        $data = [
            'status' => 'error',
            'message' => 'User or password not valid!!',
        ];


        if (is_object($user) && password_verify($password, $user->getPassword())) {
            $signup = true;
        }

        if ($signup) {
            $token = [
                'sub' => $user->getId(),
                'email' => $user->getEmail(),
                'name' => $user->getName(),
                'surname' => $user->getSurname(),
                'iat' => time(),
                'exp' => time() + (7 * 24 * 60 * 60),
            ];

            $token = JWT::encode($token, $this->key, 'HS256');

            if (!$getHash) {
                $data = [
                    'status' => 'success',
                    'token' => $token,
                ];
            } else {
                $data = $token;
            }
        }


        return $data;
    }

    public function checkToken($token, $getIdentity = false)
    {
        $auth = false;

        try {
            $decoded = JWT::decode($token, $this->key, ['HS256']);
        } catch (\UnexpectedValueException | \DomainException $e) {
            $auth = false;
        }

        if (isset($decoded) && is_object($decoded) && isset($decoded->sub)) {
            $auth = true;
        }

        if ($getIdentity) {
            return $decoded;
        }

        return $auth;
    }
}