public function userInfo()
    {
        $this->startBrokerSession();
        $user = null;

        $username = $this->getSessionData('sso_user');

        if ($username) {
            $user = $this->getUserInfo($username);
            if (!$user) return $this->fail("User not found", 500); // Shouldn't happen
        }

        header('Content-type: application/json; charset=UTF-8');
        echo json_encode($user);
    }