#!/bin/sh
# /usr/sbin/sshd-keymanager.sh
# 
#  Copyright: ©2007–2015, Güralp Systems Ltd.
#  Author: Laurence Withers <lwithers@guralp.com>
#  License: GPLv3
#

SSH_CONF_DIR="/etc/ssh.local"

if [ $# -ne 1 -o "$1" = "--help" ]
then
	echo "Usage:"
	echo ""
	echo "  sshd-keymanager ACTION"
	echo ""
	echo "Valid actions are:"
	echo "  install        Installing any missing keys."
	echo "  regenerate     Remove existing keys and install new keys."
	echo "  regen_dsa      Regenerate v2 DSA key."
	echo "  regen_rsa      Regenerate v2 RSA key."
	echo "  regen_ecdsa    Regenerate ECDSA key."
	echo "  regen_ed25519  Regenerate ED25519 key."
	exit 1
fi

regen_dsa() {
	echo " * Creating new v2 DSA key"
	KEY="${SSH_CONF_DIR}/ssh_host_dsa_key"
	rm -f "${KEY}"
	ssh-keygen -t dsa -f "${KEY}" -N ''
}

regen_rsa() {
	echo " * Creating new v2 RSA key"
	KEY="${SSH_CONF_DIR}/ssh_host_rsa_key"
	rm -f "${KEY}"
	ssh-keygen -t rsa -f "${KEY}" -N ''
}

regen_ecdsa() {
	echo " * Creating new ECDSA key"
	KEY="${SSH_CONF_DIR}/ssh_host_ecdsa_key"
	rm -f "${KEY}"
	ssh-keygen -t ecdsa -f "${KEY}" -N ''
}

regen_ed25519() {
	echo " * Creating new ED25519 key"
	KEY="${SSH_CONF_DIR}/ssh_host_ed25519_key"
	rm -f "${KEY}"
	ssh-keygen -t ed25519 -f "${KEY}" -N ''
}

case $1 in
install)
	echo "Checking sshd keys..."
	[ ! -e "${SSH_CONF_DIR}/ssh_host_dsa_key" ] && regen_dsa
	[ ! -e "${SSH_CONF_DIR}/ssh_host_rsa_key" ] && regen_rsa
	[ ! -e "${SSH_CONF_DIR}/ssh_host_ecdsa_key" ] && regen_ecdsa
	[ ! -e "${SSH_CONF_DIR}/ssh_host_ed25519_key" ] && regen_ed25519
	echo " * Done"
	true
	;;

regenerate)
	echo "Regenerating sshd keys..."
	regen_dsa
	regen_rsa
	regen_ecdsa
	regen_ed25519
	echo " * Done"
	;;

regen_dsa)
	regen_dsa
	;;

regen_rsa)
	regen_rsa
	;;

regen_ecdsa)
	regen_ecdsa
	;;

regen_ed25519)
	regen_ed25519
	;;

*)
	echo "Unrecognised action '$1'"
	exit 1
	;;
esac