deluxe-stylez.de :: unix – brain required

#!/bin/bash
# kumar.mcmillan -at- farmdev.com
 
function usage()
{
echo ""
echo "Authorizes a host for automatic SSH use by sending your key to the remote host ..."
echo "Usage: $0 remote_host_to_authorize [username:=defaults to current username]"
echo ""
}
 
function cleanup()
{
if [ -f $TEMP_PUB_KEY_XFER ]
then
rm $TEMP_PUB_KEY_XFER
fi
}
 
function exit_on_error()
{
cleanup
exit 1
}
 
if [ $# -lt 1 -o "$1" = "-h" -o "$1" = "--help" ]
then
usage
exit 0
fi
 
PUB_KEY=~/.ssh/id_dsa.pub
if [ $# -eq 2 ]; then
USER=$2
else
USER=`whoami`
fi
HOST_TO_AUTH=$1
TEMP_PUB_KEY_XFER=/tmp/$USER"_TEMP_KEY"
 
echo "checking for $PUB_KEY ..."
if [ ! -f $PUB_KEY ]; then
echo "generating your dsa public key (leave passphrase blank and save to $PUB_KEY when prompted) ..."
ssh-keygen -t dsa
if [ $? -ne 0 ]; then
echo "ssh-keygen failed"
exit_on_error
fi
fi
echo "OK"
 
echo "for the following commands you will be asked to supply your password for $HOST_TO_AUTH :"
 
echo "copying a temp pub key to $HOST_TO_AUTH ..."
cat $PUB_KEY > $TEMP_PUB_KEY_XFER
chmod 700 $TEMP_PUB_KEY_XFER
echo "OK"
 
remote_key=`basename $TEMP_PUB_KEY_XFER`
scp $TEMP_PUB_KEY_XFER $USER@$HOST_TO_AUTH:~/$remote_key
if [ $? -ne 0 ]; then
echo "scp failed"
exit_on_error
fi
 
echo "authorizing $HOST_TO_AUTH for automatic SSH use ..."
ssh $USER@$HOST_TO_AUTH "cat ~/$remote_key >> ~/.ssh/authorized_keys; rm ~/$remote_key"
if [ $? -ne 0 ]; then
echo "ssh failed"
exit_on_error
fi
echo "OK"
 
cleanup
echo "authorization successful!  you can now login automatically to $HOST_TO_AUTH"
exit 0