public static function Authenticate($email, $password, $level_required)
 {
     $perfil = Perfil::with('user')->where('email', '=', $email)->get();
     if (count($perfil) == 0) {
         return false;
     } else {
         $salt = $perfil[0]->user->salt;
         $hash = hash('sha256', $password . $salt);
         if ($hash == $perfil[0]->user->passwd) {
             self::loadProfil($perfil[0]->user);
             if (self::checkAccessRights($level_required)) {
                 return true;
             } else {
                 return false;
             }
         } else {
             return false;
         }
     }
 }
 public function cursosView($username)
 {
     $username = strip_tags(htmlspecialchars($username));
     $username = filter_var($username, FILTER_SANITIZE_STRING);
     $perfil = Perfil::with('user', 'cursos')->where('username', '=', $username)->get();
     $perfil = $perfil[0];
     $session = Utilities::getSession();
     $links = Utilities::getMenu($session);
     $logged = null;
     foreach ($perfil->cursos as $key => $value) {
         $value->action = '/curso/' . $value->nombre;
     }
     if (is_null($session)) {
         $logged = false;
     } else {
         $logged = true;
     }
     $this->view = new MisCursos($perfil, $logged, $links);
     $this->view->display();
 }