gpg_tools.sh

#!/usr/bin/env bash

# setup your master key
PGP_KEY=0xAAAAAAA
# GPG backup path
pgp_backup=/backup_path/folder

# Check $pgp_backup folder is exist
[ ! -d $pgp_backup ] && exit 1

function gpg_update_home () {
    if [ -d ~/.gnupg ]; then
        backup_path=~/.gnupg.backup.$RANDOM
        mv ~/.gnupg $backup_path
        unset backup_path
    fi

    # copy old .gnupg folder
    rsync -avqp --chmod=D700,F600 --exclude '*.backup' $pgp_backup $HOME
}

function gpg_remove_master_key () {
    gpg_export_path=$(dirname $pgp_backup)/subkeys.acs
    # export secret-subkeys
    gpg --export-secret-subkeys $PGP_KEY > $gpg_export_path
    gpg --delete-secret-key $PGP_KEY
    gpg --import $gpg_export_path
}

function gpg_clean_up() {
    unset PGP_KEY
    unset pgp_backup
    unset gpg_export_path
}

gpg_update_home
gpg_remove_master_key
gpg_clean_up