The Research And Implement Of Network Security Protocol-SSH

With the use of network become popular, the size of network is bigger than before, the remote control and manages of network equipment also become more and more necessary. Now the main methods used in remote management are telnet and Web.Though they also have user authentication scheme to prohibit un-authorized user from enthering in, these methods all have a severe bug. Their data transferred between Client and Server is plaintext, it is so easy for some others to filch the important information of the authorized user, and use this imformation to log in network epuipment.This paper begins from the security threat in remote log in network, as discuss above, analyses the causation of these threats, and reviews the main network security technology used now, especially SSH.SSH, Secure Shell is a security communication protocol in application layer. It uses an encrypted and safe channel to protect the exchange data between client and server; uses several users-authenticate methods provided by the authentication layer of it to prohibit un-authorized user from enthering in; uses the connection layer to provide security for various application protocol.In the paper, a full analysis to the framework of SSH protocol is given.It can divide into three layers: transport layer, authentication layer and connection layer. There is two main version of SSH now, SSH1.5 and SSH 2.0, in this paper we also have a compare of the two version.The details of implement of SSH protocol in huawei-3com's software plat are introduced in this paper. The introduction is mainly based on SSH version 2.0, including Stelnet and SFTP.The main work I have done includes the implement of Stelnet and SFTP in H3C's VRP software plat, the improment of the user-authentication frame of our previous implement,the implement of SSH in IPv6 network and the implement DSA algorithm in SSH.