SSH - Client and Server

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Revision as of 13:41, 13 April 2008 by Apos (talk | contribs) (A little script to enable passwordless login)

A little script to enable passwordless login

Needless to say, that using this script you should exactly know what you are doing.

!! The author takes NO response for all kinds of damage and security issues that could happen using this script !!

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Source Code

#!/bin/bash
#
# This scripts exports THIS computers public ssh key to
# a clients's ~/.ssh/authorized_keys2 file.
#
# This will enable passworless login from THIS pc to the client.
#
# You need to have the password, username and IP/alias of the other pc.

client="$1"
NAME="$2"

[ "$NAME" ] || NAME="${USER}"
[ "$client" ]  || echo "ERROR: You have to specify at least a client IP or alias."
[ "$client" ]  || exit 1

cd ~/.ssh

echo "Create ssh dir on client ... "
ssh ${NAME}@$client "mkdir -p ~/.ssh; chmod 700 ~/.ssh"

echo "Check if pub key exist and/or create one ... "
[ -e id_dsa.pub ] || ssh-keygen -t dsa 

echo "Copy the public key of THIS pc to the client ... "
scp id_dsa.pub ${NAME}@$client:~/.ssh/id_dsa.pub_${HOSTNAME}

echo "We make an entry into the authorized_keys file on the client ... "
ssh ${NAME}@$client "cat ~/.ssh/id_dsa.pub_${HOSTNAME} \
   >> ~/.ssh/authorized_keys2; \
   rm ~/.ssh/id_dsa.pub_${HOSTNAME}"

echo "Secure the local public key ... "
chmod 600 id_dsa.pub

echo TEST:
echo Now we test with running the following terminal command:
echo "  ssh ${NAME}@$client echo Congratulation: You can login passwordless to your client $client."
echo ;
ssh ${NAME}@$client "echo Congratulation: You can login passwordless to your client $client."

echo ;
echo ;
echo Program ended.
echo ;
echo If you like to remove the automatic login, you have to 
echo remove the public key in the file /home/${NAME}/.ssh/authorized_keys2
echo on your clients - $client - computer.