eZ\Publish\Core\MVC\Symfony\Security\EventListener\SecurityListener::onKernelRequest PHP Method

    public function onKernelRequest(GetResponseEvent $event)
    {
        $request = $event->getRequest();
        // Ignore sub-requests, including fragments.
        if (!$this->isMasterRequest($request, $event->getRequestType())) {
            return;
        }
        $siteAccess = $request->attributes->get('siteaccess');
        if (!$siteAccess instanceof SiteAccess) {
            return;
        }
        $token = $this->tokenStorage->getToken();
        if ($token === null) {
            return;
        }
        if ($request->attributes->get('_route') !== 'login' && !$this->hasAccess($siteAccess, $token->getUsername())) {
            throw new UnauthorizedSiteAccessException($siteAccess, $token->getUsername());
        }
    }

 public function onKernelRequest(GetResponseEvent $event)
 {
     // In legacy_mode, roles and policies must be delegated to legacy kernel.
     if ($this->configResolver->getParameter('legacy_mode')) {
         return;
     }
     parent::onKernelRequest($event);
 }