docker-mailserver/target/bin/generate-dkim-config

#! /bin/bash

touch /tmp/vhost.tmp

# if no keysize is provided, 2048 is default.
KEYSIZE=${1:-4096}
# optional domain names
DOMAINS=${2:-}

if [[ -z ${DOMAINS} ]]
then
    # getting domains FROM mail accounts
    if [[ -f /tmp/docker-mailserver/postfix-accounts.cf ]]
    then
        # shellcheck disable=SC2034
        while IFS=$'|' read -r LOGIN PASS
        do
            DOMAIN=$(echo "${LOGIN}" | cut -d @ -f2)
            echo "${DOMAIN}" >>/tmp/vhost.tmp
        done < <(grep -v "^\s*$\|^\s*\#" /tmp/docker-mailserver/postfix-accounts.cf || true)
    fi

        # Getting domains FROM mail aliases
    if [[ -f /tmp/docker-mailserver/postfix-virtual.cf ]]
    then
        # shellcheck disable=SC2034
        while read -r FROM TO
        do
            UNAME=$(echo "${FROM}" | cut -d @ -f1)
            DOMAIN=$(echo "${FROM}" | cut -d @ -f2)

            test "${UNAME}" != "${DOMAIN}" && echo "${DOMAIN}" >>/tmp/vhost.tmp
        done < <(grep -v "^\s*$\|^\s*\#" /tmp/docker-mailserver/postfix-virtual.cf || true)
    fi
else
    tr ',' '\n' <<<"${DOMAINS}" > /tmp/vhost.tmp
fi

# keeping unique entries
if [[ -f /tmp/vhost.tmp ]]
then
  sort < /tmp/vhost.tmp | uniq >/tmp/vhost && rm /tmp/vhost.tmp
fi

# exit if no entries found
if [[ ! -f /tmp/vhost ]]
then
  echo "No entries found, no keys to make"
  exit 0
fi

while read -r DOMAINNAME
do
  mkdir -p "/tmp/docker-mailserver/opendkim/keys/${DOMAINNAME}"

  if [[ ! -f "/tmp/docker-mailserver/opendkim/keys/${DOMAINNAME}/mail.private" ]]
  then
    echo "Creating DKIM private key /tmp/docker-mailserver/opendkim/keys/${DOMAINNAME}/mail.private"

    opendkim-genkey --bits="${KEYSIZE}" --subdomains --DOMAIN="${DOMAINNAME}" --selector=mail -D "/tmp/docker-mailserver/opendkim/keys/${DOMAINNAME}"
  fi

  # write to KeyTable if necessary
  KEYTABLEENTRY="mail._domainkey.${DOMAINNAME} ${DOMAINNAME}:mail:/etc/opendkim/keys/${DOMAINNAME}/mail.private"
  if [[ ! -f "/tmp/docker-mailserver/opendkim/KeyTable" ]]
  then
    echo "Creating DKIM KeyTable"
    echo "${KEYTABLEENTRY}" > /tmp/docker-mailserver/opendkim/KeyTable
  else
    if ! grep -q "${KEYTABLEENTRY}" "/tmp/docker-mailserver/opendkim/KeyTable"
    then
        echo "${KEYTABLEENTRY}" >>/tmp/docker-mailserver/opendkim/KeyTable
    fi
  fi

  # write to SigningTable if necessary
  SIGNINGTABLEENTRY="*@${DOMAINNAME} mail._domainkey.${DOMAINNAME}"
  if [[ ! -f /tmp/docker-mailserver/opendkim/SigningTable ]]
  then
    echo "Creating DKIM SigningTable"
    echo "*@${DOMAINNAME} mail._domainkey.${DOMAINNAME}" >/tmp/docker-mailserver/opendkim/SigningTable
  else
    if ! grep -q "${SIGNINGTABLEENTRY}" /tmp/docker-mailserver/opendkim/SigningTable
    then
      echo "${SIGNINGTABLEENTRY}" >> /tmp/docker-mailserver/opendkim/SigningTable
    fi
  fi
done < <(grep -vE '^(\s*$|#)' /tmp/vhost)

# creates TrustedHosts if missing
if [[ -d /tmp/docker-mailserver/opendkim ]] && [[ ! -f /tmp/docker-mailserver/opendkim/TrustedHosts ]]
then
  echo "Creating DKIM TrustedHosts"
  echo "127.0.0.1" >/tmp/docker-mailserver/opendkim/TrustedHosts
  echo "localhost" >>/tmp/docker-mailserver/opendkim/TrustedHosts
fi