Implementation Research On Network Security Scanning System

With the rapid development of Internet, the computer network has gradually become indispensable in people's daily life. However, as the existence of the insecure factors of the network and the limitations of the network communication protocols, it brings the possibility for the invaders to attack the network. Also, operating system has its own security weakness. All of these provide a number of approaches for the attacker. Therefore, it becomes an important research issue in the field of network security as how to find the security problems that can be found in the network system, to remedy the security leaks, and to minimize the security risk.Considering the present popular techniques and tools for network security scan, the key techniques which include port scan, weak password scan, operating system probe and vulnerability scan for network security scan are expounded. Also, the TCP/IP (Transmission Control Protocol/Internet Protocol) protocols, the transmission mechanism as Windows Sockets and the technique about dynamic link library are described. Then, the operating principle and the realization method of these various techniques are discussed. Aimed at the requirement of special application, the design idea and principle of the NSS (Network Security Scanner) which is a network security scanning system are expressed. The analysis and design about the system framework, the primary functional modules and the workflow are explained in detail. Five main components of the NSS including main procedure, port scan, weak password scan, operating system probe and vulnerability scan are discussed detailedly, together with the workflow and the related data structures. The techniques of plug-in and multi-thread, which can strengthen the expansibility and improve the scanning speed and performance of the NSS, are adopted in the process of system actualization.Executive results show that the prospective scanning functions of NSS are achieved. The system has certain practical value to help a network administrator to improve and defense the network security.