Add key to remote machine

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DRAFT - INCOMPLETE - DRAFT - INCOMPLETE

Here is a shell script that I keep around to add a public key to a remote machine (so it doesn't prompt you for a password on ssh login. It does not make the keys on the local machine secure, so a security breach on this machine will also breach the account on the remote machine. A description of the options processing is here.

You can fetch this script with this command, assuming you have curl installed :

curl --output key_machine.sh http://bsdtips.utcorp.net/mediawiki/index.php\?title=Key_machine.sh\&action=raw

Or view it here key_machine.sh

#!/bin/sh

       args=`getopt nh:u: $*`
       if [ $? -ne 0 ]
       then
               echo 'Usage: ...'
               echo '-h host to key'
               echo '-u usename to key on host'
               echo '-n no op'
               exit 2
       fi
       set -- $args

       for i
       do
               case "$i"
               in
               -n)
                       NOOP=YES
                       shift;;
               -h)
                       HOST=$2
                       shift; shift;;
               -u)
                       UNAME=$2
                       shift; shift;;
               --)
                       shift
                       break;;
               esac
       done

       if [ X${HOST} = X ]; then echo "HOST not set"; exit; else echo "HOST is $HOST"; fi

       if [ X${UNAME} = X ]; then echo "using current login"; UNAME=${USER}; else echo "UNAME is ${UNAME}"; fi

#
# make sure the keys are where we expect them
#
       if [ -e ~/.ssh/id_rsa.pub ]
       then
               echo "using ~/.ssh/id_rsa.pub"
       else
               echo "creating ~/.ssh/id_rsa.pub"
               ssh-keygen -t rsa -f ~/.ssh/id_rsa
       fi

       RSAKEY=`cat ~/.ssh/id_rsa.pub`
#
# send the pub key up, make sure permissions are correct
#
       echo "you will be prompted for the remote password 3 times"
       ssh ${UNAME}@${HOST} mkdir .ssh
       ssh ${UNAME}@${HOST} "echo $RSAKEY >> .ssh/authorized_keys"
       ssh ${UNAME}@${HOST} chmod 400 .ssh/authorized_keys