ManchesterWireless

Neat Trick

I'm testing routing on my network of radio nodes.

This involves a lot of root access to the nodes and file moves
through my firewall. Repeated setting up of root sessions to
each node every time I set up to test was getting under my skin,
so when I came across this tech note it motivated me to come up
with something easier.

stupid-protocols

The section titled Secure shell - Simple Remote Login
caught my eye. What follows is a cookbook set up largely derived
from that note. Note this is only appropriate from a Linux
workstation. Something similar may be possible from Windows
but I'm the wrong person to ask if it is.

The following works on RedHat 8.0 and 9.0 at least.
My main workstation runs KDE

First

Generate yourself a pass phrase of a strength you are happy with.

Diceware site

For a reasonable discussion and recommendations.

Second

On a console terminal (Konsole, xterm, eterm etc)
on your "Safe, secure, internal" workstation, type:-

ssh-keygen -t rsa

To generate a 1024 bit RSA key.

Secure this key with your shiny new pass phrase.

Third

Copy the file .ssh/id_rsa.pub (your new public key you
just generated) to :-

/root/.ssh/authorized_keys

on the target nodes that you want to control.

SCP is your friend! ;)

(append the key if the file already exists)

Fourth

Test by typing:-

ssh-agent /bin/bash

ssh-add

and answering the prompt with your shiny new pass phrase.

then:-

ssh -v root@yournode

and if all is well, you have a root session on yournode

Fifth

Automate this with a script file as below
(names resolve to router node addresses via my local DNS)

#! /bin/bash
ssh-agent /bin/bash &
ssh-add
konsole -e ssh root@pei &
konsole -e ssh root@aichen &
konsole -e ssh root@liang &

This will open three concurrent console windows and from each
start an ssh connection to a target node, automatically authenticating
you via the public key held on the remote node.

The foreground console remains open and also has access to your keyfile
so an SCP command from here, for instance, will automatically and
securely authenticate to the target node, without further action
on your part.

I have this script as startall

I admit I posed the windows, but the logins are real...

View image

Harry Moyes

Posted by harry at July 4, 2003 12:20 AM