Install SSH Keys

gistfile1.sh

#!/bin/sh

USER="${1}"
HOST="${2}"
ALIAS="${3}"

if [ ! "${USER}" ] && [ ! "${HOST}" ] && [ ! "${ALIAS}" ]; then
	echo
	echo "Usage: installSSHKey username hostname alias"
	echo
	echo "  username = Your username on the remote system (not necessarily your current username: `whoami`)"
	echo "  hostname = The hostname (domain name or IP address) of the remote server"
	echo "  alias    = The ssh alias for this host to be created"
	echo
fi

if [ ! "${USER}" ]; then
	echo "No ssh username specified (EG: `whoami`)"
	exit 1
fi

if [ ! "${HOST}" ]; then
	echo "No hostname specified (EG: www.example.com)"
	exit 1
fi

if [ ! "${ALIAS}" ]; then
	echo "No ssh alias specified (EG: example)"
	exit 1
fi

echo "Public keys will be generated and installed on the ssh"
echo "host ${USER}@${HOST} identified by the key ${ALIAS}."
echo -n "If this is correct, type yes: "
read YESNO

if [ ! "${YESNO}" == "yes" ]; then
	exit 0
fi

cd ~

if [ ! -r .ssh ]; then
	echo -n "Creating hidden .ssh folder in home directory..."
	mkdir -p .ssh
	chmod 700 .ssh
	echo "Done"
fi

if [ ! -r .ssh/config ]; then
	echo -n "Creating host configuration file..."
	echo "StrictHostKeyChecking=no
CheckHostIP=no" > .ssh/config
	chmod 600 .ssh/config
	echo "Done"
fi

echo -n "Adding host to config file..."
echo "
Host ${ALIAS}
	HostKeyAlias ${ALIAS}
	Hostname "${HOST}"
	User ${USER}
	Compression yes" >> .ssh/config
echo "Done"

if [ ! -r .ssh/id_rsa.pub ]; then
	echo -n "Creating RSA private and public keys..."
	ssh-keygen -q -t rsa -f .ssh/id_rsa -N "" -P ""
	chmod 600 .ssh/id_rsa*
	echo "Done"
fi

if [ ! -r .ssh/id_dsa.pub ]; then
	echo -n "Creating DSA private and public keys..."
	ssh-keygen -q -t dsa -f .ssh/id_dsa -N "" -P ""
	chmod 600 .ssh/id_dsa*
	echo "Done"
fi

echo "Installing SSH public keys onto server: ${HOST}..."
echo "You will be prompted for your remote password."
ssh "${ALIAS}" \
	mkdir -p .ssh\; \
	echo "`cat .ssh/id_rsa.pub`" \>\> .ssh/authorized_keys\; \
	echo "`cat .ssh/id_dsa.pub`" \>\> .ssh/authorized_keys2\; \
	chmod 700 .ssh\; \
	chmod 600 .ssh/*\;

if [ ! $? == 0 ]; then
	echo "An error occurred, please overview your output"
else
	echo "Done"
	echo
	echo "You can now access the server ${HOST} by typing:"
	echo
	echo "  ssh ${ALIAS}"
	echo
	echo "Commands can be performed without logging in by doing:"
	echo
	echo "  ssh ${ALIAS} commandname"
	echo
	echo "Examples:"
	echo "  ssh ${ALIAS} whoami"
	echo "  ssh ${ALIAS} ps ax"
	echo "  ssh ${ALIAS} tail -f /var/log/system.log"
	echo
fi

chmod 600 .ssh/*