code: def parse_message(self, msg, msg_signature, timestamp, nonce):
          
          content = self.crypto.decrypt_message(msg, msg_signature, timestamp, nonce)
          message = xmltodict.parse(to_text(content))['xml']
          message_type = message['InfoType'].lower()
          message_class = COMPONENT_MESSAGE_TYPES.get(message_type, ComponentUnknownMessage)
          msg = message_class(message)
          if msg.type == 'component_verify_ticket':
              self.session.set(msg.type, msg.verify_ticket)
          elif msg.type in ('authorized', 'updateauthorized'):
              msg.query_auth_result = self.query_auth(msg.authorization_code)
          return msg
docs: 处理 wechat server 推送消息
  
          :params msg: 加密内容
          :params msg_signature: 消息签名
          :params timestamp: 时间戳
          :params nonce: 随机数