Socks Firewall And Implementation

With the rapid development of Internet and Intranet, firewall has become an important icasure to protect the security of Intranet. SOCKS firewall technique is a pretty good firewall technique, but it starts lately in our country. Because some departments of country shouldn't use the security products of foreign country, it is an urgent project to research the internal detailed realization and relative technique of SOCKS firewall. Firstly, the thesis analyzes and compares firewall techniques of each levels; after that it introduces the theory of SOCKS firewall, and analyzes and researches the SOCKS V5 protocol and security mechanism of SOCKS technique. On this basis, it realizes the basic functions of SOCKS firewall. This thesis makes emphases on the realization of new functions of SOCKS V5: the realization of UDP application and realization of authorization mechanism. Among that, the realization of authorization mechanism includes the realization of username/password authorization and GSS-API authorization. The thesis analyzes the theory, procedure and interface of GSS-API, and on the basis of analyzing SOCKS/GSS-API protocol, realizes the GSS-API authorization in our SOCKS firewall. Finally, the thesis summarizes the frame and flow of the system, and brings forward the design of the system extension.