#!/bin/sh

# Copyright (c) 2016 Peter Palfrader <peter@palfrader.org>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

set -e
set -u

cd ~/certs

if [ "$#" = 0 ]; then
  echo >&2 "Usage: $0 <fqdn> [..]"
  exit 1
fi

cn="$1"
shift

if ! [ -e "$cn.key" ] ; then
  echo >&2 "$cn.key does not exist."
  exit 1
fi

if [ "$#" = 0 ]; then
  openssl req -new -sha256 -key "$cn.key" -subj "/CN=$cn" -out "$cn.csr"
  openssl x509 -req -days 365 -in "$cn.csr" -signkey "$cn.key" -out "$cn-selfsigned.pem"
else
  tmp="`tempfile`"
  trap "rm -f '$tmp'" EXIT
  (
    cat /etc/ssl/openssl.cnf
    echo "[SAN]"
    echo -n "subjectAltName=DNS:$cn"
    for i in "$@"; do
      echo -n ",DNS:$i"
    done
    echo
  ) > "$tmp"
  openssl req -new -sha256 -key "$cn.key" -subj "/" -reqexts SAN -config "$tmp" -out "$cn.csr"
  openssl x509 -req -days 365 -in "$cn.csr" -signkey "$cn.key" -extensions SAN -extfile "$tmp" -out "$cn-selfsigned.pem"
fi