1. ORAFACT The Secure Shell

2. ORAFACT Secure Shell Replaces unencrypted utilities rlogin and telnet rsh rcp Automates X11 authentication Supports tunneling of other protocols POP, IMAP HTTP PPP Supports user RSA/DSA keys for password-less logins

3. ORAFACT ssh and sshd Configuration Server daemon – sshd /etc/ssh/sshd_config The main configuration file for sshd. Lists which features will be supported (Protocol, X11Forwarding, PermitRootLogin, Compression, Cihpers, etc). The 50+ supported options are well described in the man page sshd_config(5). /etc/ssh/ssh_host_key{,.pub} The private and public keys that the server uses. These are normally created the first time sshd is started, and are used during the host authentication process. /etc/ssh/sshrc Contains a list of commands that the SSH server should execute when an SSH client connects. These commands are run for all users just before the shell is started../.ssh/rc (no longer normally used) Same use as the global /etc/ssh/sshrc file, but specific to a user.

4. ORAFACT ssh and sshd Configuration Secure Shell Client – ssh /etc/ssh/ssh_config The main configuration file for the SSH client commands. Lists which features will be requested or supported (Protocol, Compression, Cihpers, NumberOfPasswordPrompts, etc). The 50+ supported options are well described in the man page ssh_config(5)../.ssh/config Same use as the global /etc/ssh/ssh_config file, but specific to a user../.ssh/id_{rsa,dsa}{,.pub} User specific public and private keys that are used when attempting key-based authentication../.ssh/known_hosts

5. ORAFACT Accessing Remote Shells Encrypted Logins ssh user@host - remote interactive login ssh user@host command - remote non-interactive command execution Escape Sequences An escape sequence is a key sequence that tells SSH to send a specific control message or switch to another mode. ~.  which quickly closes the connection ~?  which prints a list of available escapes.

6. ORAFACT Transferring Files Encrypted File Transfers sftp - interactive file transfer ($ sftp guest@of4 ) scp - non-interactive file transfer ($ scp /etc/passwd guest@of4:/tmp Alternative sftp Clients Command-line sftp Interfaces lftp mc Graphical sftp Interface konqueror nautilus