code: def verify_enroll(self, response):
          
  
          seed = session.pop('_u2f_enroll_')
          try:
              new_device, cert = complete_register(seed, response, self.__facets_list)
          except Exception as e:
              if self.__call_fail_enroll:
                  self.__call_fail_enroll(e)
  
              return {
                  'status' : 'failed', 
                  'error'  : 'Invalid key handle!'
              }
  
          finally:
              pass
  
          
  
          devices = self.__get_u2f_devices()
  
          # Setting new device counter to 0
          new_device['counter'] = 0
          new_device['index']   = 0
  
          for device in devices:
              if new_device['index'] <= device['index']:
                  new_device['index'] = device['index'] + 1
  
          devices.append(new_device)
  
          self.__save_u2f_devices(devices)
          
          self.__call_success_enroll()
  
          return {'status': 'ok', 'message': 'Successfully enrolled new U2F device!'}
docs: Verifies and saves U2F enroll