Analysis and implementation of secure console server based on embedded Linux

Many devices are managed through serial interface nowadays, but if devices controlled are located in different places with administrator, the configuration may be inconvenient. System specified in this paper is a scheme basically for remote control of serial devices. It is an embedded system based on Linux, and it can connect many other serial devices through serial interfaces. With the system, users can securely access the serial devices connected to it through network. Traditional serial server is somewhat functionally similar, but it just translates protocols between network and serial interface, and there is no security control. RFC2217 recommends a way of accessing serial devices with telnet, but data transported through telnet are not encrypted, so it is still not secure. In addition to security of operating system, this system can guarantee data security with SSH and HTTPS protocols. The Web server running on the operating system adopts many ways to ensure the user and network security. This paper analyses security of this system from operation system, web server and other applications, and illustrates the contents about user authentication, network transportation, dialing access, code security, firewall etc, and it contributes to computer security research.