public function SignUpAction(Request $request)
{
    $user = new User();
    $em = $this->getDoctrine()->getManager();
    $form = $this->createForm(SignUpType::class, $user);

    $form->handleRequest($request);

    if ($form->isSubmitted() && $form->isValid()) {

        $newUser = $form->getData();
        $password = $this->get('security.password_encoder')
            ->encodePassword($user, $newUser->getPassword());
        $user->setSalt(md5(time()));
        $user->setPassword($password);
        $user->setIsActive(true);
        $user->setEmail($newUser->getEmail());
        $user->setUsername($newUser->getUsername());
        $user->setStatus(true);

        $role = $em->getRepository('AppBundle:Role')
            ->findByName('ROLE_ADMIN');
        $user->getUserRoles()->add($role);
        $em->persist($user);
        $em->flush();

        return $this->redirectToRoute('AppBundle_homepage');

    }


    return $this->render('AppBundle:Security:signup.html.twig', array(
        'form' => $form->createView()
    ));
}

[2016-09-08 18:30:49] security.INFO: Authentication request failed. {"exception":"[object] (Symfony\Component\Security\Core\Exception\BadCredentialsException(code: 0): Bad credentials. at /var/www/symfony.first/vendor/symfony/symfony/src/Symfony/Component/Security/Core/Authentication/Provider/UserAuthenticationProvider.php:90, Symfony\Component\Security\Core\Exception\BadCredentialsException(code: 0): The presented password is invalid. at /var/www/symfony.first/vendor/symfony/symfony/src/Symfony/Component/Security/Core/Authentication/Provider/DaoAuthenticationProvider.php:67)"} []

$token = new UsernamePasswordToken($user, $user->getPassword(), "main", $user->getRoles());
        $this->get("security.token_storage")->setToken($token);

        $event = new InteractiveLoginEvent($request, $token);
        $this->get("event_dispatcher")->dispatch("security.interactive_login", $event);

security:
encoders:
    AppAppBundleEntityUser:
        algorithm: sha512
        encode-as-base64: true
        iterations: 10

providers:
    main:
        entity: { class: AppBundle:User, property: username }

firewalls:
    main:
        pattern: /.*
        form_login:
            check_path: /login_check
            login_path: /login/
        logout: true
        security: true
        anonymous: true
        remember_me:
            secret:   '%secret%'
            lifetime: 604800 # 1 week in seconds
            path:     /
                        # by default, the feature is enabled by checking a
                        # checkbox in the login form (see below), uncomment the
                        # following line to always enable it.
                        #always_remember_me: true

access_control:
    - { path: /admin/.*, role: ROLE_ADMIN }
    - { path: ^/login/, roles: IS_AUTHENTICATED_ANONYMOUSLY }
    - { path: /.*, role: IS_AUTHENTICATED_ANONYMOUSLY }