How to identify if a user is being impersonated in Symfony2?

Question

In an application built with Symfony2 we want superadmins to be able to impersonate other users. This is easily done by giving the superadmin user the ROLE_ALLOWED_TO_SWITCH role. The switching is implemented with a call to "somewhere?_switch_user=" as suggesed in the reference documentation.

The problem however, is to detect in a template if the current user is actually impersonated so as to print a link to "somewhere?_switch_user=_exit" on the page, thus enabling the impersonating user to return to her real user.

Answer 1

I haven't been using Symfony2 for a while so I'm not sure, but when you switch to another user you gain all roles assigned to that user and one extra role: ROLE_PREVIOUS_ADMIN. So I guess all you need to do is to use voter to check whether such a role is assigned to the current user using voter.

// Twig  {% if is_granted('ROLE_PREVIOUS_ADMIN') %}     <a href="...?_switch_user=_exit">EXIT</a> {% endif %}  // PHP  <?php if ($view['security']->isGranted('ROLE_PREVIOUS_ADMIN')): ?>     <a href="...?_switch_user=_exit">EXIT</a> <?php endif ?> 

Answer 2

An example of how to get more details about the impersonator:

use Symfony\Component\Security\Core\Role\SwitchUserRole;   $sec = $this->get('security.context');  if($sec->isGranted('ROLE_PREVIOUS_ADMIN')) {   foreach($sec->getToken()->getRoles() as $role) {     if ($role instanceof SwitchUserRole) {       $admin_user = $role->getSource()->getUser();     }   } } 

You then have admin_user as the original user object. Remember to use the SwitchUserRole.