This article presents an overview of SSH, the Crypto key generate ssh SHell. OSSH which are presented in an accompanying Part2. Linux system should be installed without it.
SuSE and bundled SSH with the OS. SSH has become the standard workhose for many sysadmin tasks, but has also had security bugs, possibly making your system more insecure than if using a simple telnet! Even SSH is not immune to the tiring vulnerability-patch-update cycle. Italian Readers: Please note that an earlier version of this article has been translated into Italian . Finland, is a secure replacement for Telnet, rlogin, rcp, rsh and provides secured TCP tunnels.
The Telnet, rlogin, rcp, rsh commands have a number of security weakness: all communications are in clear text and no machine authentication takes place. IP address spoofing where an attack hosts pretends to be a trusted host by sending packets with the source address of the trusted host. SSH is encrypted on the network, SSH must communicate in clear text with the terminal device. Features SSH can be used to log-in securely into another computer over a network, execute commands on a remote machine, and copy files from one machine to another. SSH provides strong authentication and secure communications over insecure channels. It is intended as a replacement for rlogin, rsh, and rcp. Additionally, SSH provides secure X11 connections and secure forwarding of arbitrary TCP connections.
Three types of trust exist: shosts, rhosts compatible and RSA. Client runs on the above, plus Windows and many other platforms. Data compression can be enabled to improve performance over slow network links. SOCKS is a general proxy protocol, originally sponsored by NEC, but now available from several vendors. SSH2 is the newer protocol version, submitted to the IETF for approval by SSH Communications . SSH1 if a client requests SSH1 protocols and SSH1 is available. Compatible with SSH1, when ssh1 has been installed prior to ssh2.