#!/bin/bash

# generate new ca certificate, roll over the old one(s)

set -e

key_dir='#ETCDIR#/simple-pki/keys'

if [ -r '#ETCDIR#/simple-pki/ca.conf' ]; then
  . '#ETCDIR#/simple-pki/ca.conf'
fi

if [ -n "${ca_user}" ] \
&& [ "$(whoami)" != "${ca_user}" ]; then
  exec su "${ca_user}" -c "$0"
fi

if [ -f "${key_dir}/${ca_name}.key.new" ] \
&& [ -f "${key_dir}/${ca_name}.crt.new" ]; then
  if [ "$(stat -c%Y "${key_dir}/${ca_name}.key.new")" -lt "$(($(date +%s)-60*60*24*ca_min_duration))" ] \
  || [ ! -f "${key_dir}/${ca_name}.key" ] \
  || [ "$(stat -c%Y "${key_dir}/${ca_name}.crt.new")" -lt "$(($(date +%s)-60*60*24*ca_min_duration))" ] \
  || [ ! -f "${key_dir}/${ca_name}.crt" ]; then
    mv "${key_dir}/${ca_name}.key"{.new,}
    mv "${key_dir}/${ca_name}.crt"{.new,}
  fi
fi

if [ ! -f "${key_dir}/${ca_name}.key.new" ] \
|| [ ! -f "${key_dir}/${ca_name}.crt.new" ]; then
  openssl req -new \
    -newkey rsa:4096 -sha256 \
    -keyout "${key_dir}/${ca_name}.key.new" \
    -out "${key_dir}/${ca_name}.csr.new" \
    -nodes \
    -subj "${ca_subject_prefix}"'/CN=Certification Authority' \
    -addext 'subjectKeyIdentifier = hash' \
    -addext 'basicConstraints       = critical, CA:true' \
    -addext 'keyUsage               = keyCertSign, cRLSign'
  if [ -f "${key_dir}/${ca_name}.key" ]; then
    previous_key="${key_dir}/${ca_name}.key"
  else
    previous_key="${key_dir}/${ca_name}.key.new"
  fi
  openssl req -x509 \
    -sha256 \
    -in "${key_dir}/${ca_name}.csr.new" \
    -key "${previous_key}" \
    -out "${key_dir}/${ca_name}.crt.new" \
    -days 365 -nodes \
    -addext 'subjectKeyIdentifier = hash' \
    -addext 'authorityKeyIdentifier = keyid:always, issuer' \
    -addext 'basicConstraints       = critical, CA:true' \
    -addext 'keyUsage               = keyCertSign, cRLSign'
  rm "${key_dir}/${ca_name}.csr.new"
fi

rsync --ignore-missing-args \
  "${key_dir}/${ca_name}.crt"{.new,} \
  "${remote_host}:${remote_dir}/"

(
  cd "${key_dir}"
  find . -maxdepth 1 \
    -type f \( -name "${ca_name}"'.crt' -o -name "${ca_name}"'.crt.new' \) \
    -printf '%TY-%Tm-%TdT%TT ' \
    -exec sha512sum {} \; \
  | sed '
    s/\.[0-9]\+ / /
    s@\s\s\+\(\S\+/\)\?@ @
  '
) \
| ssh "${remote_host}" '
  cd "'"${remote_dir}"'"
  while read -r time sum file; do
    rm -f ????-??-??T??\:??\:??".${file}"
    mv "${file}" "${time}.${file}"
    sed -i '"'"'
      / [^.]\+\.'"'"'"${file//./\.}"'"'"'$/d
    '"'"' sha512sums
    printf '"'"'%s  %s\n'"'"' "${sum}" "${time}.${file}" \
    >> sha512sums
  done
'