Enable SSH Version 1 on linux

Most of the linux flavors have disabled ssh version 1 due to security issues.

If you need to enable it for some reasons below are the steps.

Snip from sshd_config -->

Protocol 2,1

# HostKey for protocol version 1

HostKey /etc/ssh/ssh_host_key

# HostKeys for protocol version 2

HostKey /etc/ssh/ssh_host_rsa_key

HostKey /etc/ssh/ssh_host_dsa_key

HostKey /etc/ssh/ssh_host_ecdsa_key

Generate hostkey -->

sudo ssh-keygen -t rsa1 -f /etc/ssh/ssh_host_key -N ""

Restart sshd

agnel@ubuntu:/var/log$ ssh -1 localhost

agnel@localhost's password:

Welcome to Ubuntu 11.10 (GNU/Linux 3.0.0-16-generic i686)

* Documentation:  https://help.ubuntu.com/

Last login: Mon Apr 16 05:27:26 2012 from localhost

agnel@ubuntu:~$