Easily create a backup archive of your pgp key.

pgp_backup.sh

#!/usr/env/bin bash

set -e

function print_help() {
  echo "
Backup gpg keys and create a compressed archive for backup.
Creates the archive in the current directory.

Usage: gpg_backup.sh <email>
  "
}

POS_ARGS=()

while [[ $# -gt 0 ]]; do
  case $1 in
    -h|--help)
      print_help
      exit 0
      ;;
    -*|--*)
      echo "Unknown option $1"
      exit 1
      ;;
    *)
      POS_ARGS+=("$1")
      shift
      ;;
  esac
done

set -- "${POS_ARGS[@]}"

if [[ "${#POS_ARGS[@]}" -lt 1 ]]; then
  echo "Error: missing required argument email"
  exit 1
fi

EMAIL="${POS_ARGS[0]}"

KEY_INFO="$(gpg --list-keys --with-colons "$EMAIL" 2>/dev/null)"

gpg2 --export --armor "$EMAIL" > ${EMAIL}.pub.asc
gpg2 --export-secret-keys --armor "$EMAIL" > ${EMAIL}.priv.asc
gpg2 --export-secret-subkeys --armor "$EMAIL" > ${EMAIL}.sub_priv.asc
gpg2 --export-ownertrust > ownertrust.txt

# backup revocation certificate
# LONG_KEY_ID=$(echo "$KEY_INFO" | awk -F: '/^pub/ {print $5}')
FINGERPRINT=$(echo "$KEY_INFO" | awk -F: '/^fpr/ {print $10; exit}')
REVOC="$FINGERPRINT.rev"
if [[ ! -f "$HOME/.gnupg/openpgp-revocs.d/$REVOC" ]]; then
  echo "Warning: no revocation certificate found for $EMAIL"
  REVOC=""
else
  cp "$HOME/.gnupg/openpgp-revocs.d/$REVOC" .
fi

# create a bzip2 compressed archive
tar -cjvf \
  gpg_backup_${EMAIL}.tar.bz2 \
  ${EMAIL}.pub.asc \
  ${EMAIL}.priv.asc \
  ${EMAIL}.sub_priv.asc \
  ownertrust.txt \
  $REVOC
rm \
  ${EMAIL}.pub.asc \
  ${EMAIL}.priv.asc \
  ${EMAIL}.sub_priv.asc \
  ownertrust.txt \
  $REVOC