基于NESSUS的NTP协议的通信中间件研究

随着分布式系统技术的快速发展，三层架构的分布式系统是未来发展的主要方向，通信中间件是三层架构的分布式系统不可或缺的一层。通信中间件能扩大分布式系统的规模、支持更多的用户与服务器连接、简化用户与服务器的通信过程、保证客户机与服务器的通信过程更安全和实现跨平台使用。虽然目前存在有比较成熟的ACE和ICE通信中间件等，但是也存在一个问题--开发三层架构分布式系统的设计人员必须了解其繁多的功能和复杂的操作，然而有时候很多功能是不需要的。所以设计一款小型化、高效化的通信中间件对于开发者来说变得尤为重要。国际上一种比较流行的网络漏洞扫描系统NESSUS是一种基于C/S和B/S结构的分布式系统，其客户机和服务器之间的通信是建立在NTP（Nessus Transfer Protocol）传输协议之上的。文章重点研究NESSUS客户机和服务器之间是如何交互通信的，把通信模块封装并提供中间件接口，同时引入消息发送/接收队列缓冲池技术和SSL组件，提出一套小型的、高效的、安全的、跨平台的通信中间件，它也适用于其他客户机/服务器的三层架构的分布式系统。

The Research of NTP Protocol Communication Middleware based on the NESSUS

With the rapid development of distributed system technology, three-layer distributed system is the main direction of future development, communication middleware is a indispensable layer. Communication middleware can enlarge the scale of distributed systems, support more users to connect to the server, simplify the communication process of the user and the server, make the communication process of the client and the server more secure, realize the cross-platform application. Currently there are some mature communication middlewares, such as ACE and ICE , but there is a problem that the designers of three-layer distributed system must understand their complex functions and operations, sometime many functions are not used by designers. So designing a small, efifcient communication middleware is very important for designers. NESSUS is a popular network vulnerability scanning system in the world which is a distributed system based on C / S and B / S structure. The communication between the client and the server is built on the transport protocol of NTP. This paper focuses on how the NESSUS communicates between the client and the server, packaging the communication module and providing the middleware interfaces, while introducing message send /receive queue buffer pool technology and SSL components. Then a set of small, efifcient, secure, cross-platform communication middleware is presented, which is also applicable to other client / server three-layer distributed systems.