Example of non-interactive GPG

non-interactive-gpg.sh

#!/usr/bin/env bash

# shellcheck disable=SC2155

RED=$(printf '\033[31m')
GREEN=$(printf '\033[32m')
YELLOW=$(printf '\033[33m')
BLUE=$(printf '\033[34m')
BOLD=$(printf '\033[1m')
RESET=$(printf '\033[m')

function gen_master_key() {
  local home_dir="$(echo "${1}" | jq -r ".home_dir // \"${GNUPGHOME}\"")"
  local passphrase="$(gpg --gen-random --armor 0 24)}"
  local uid="$(echo "${1}" | jq -r '.uid')"
  local algo="$(echo "${1}" | jq -r '.algo // ""')"
  local usage="$(echo "${1}" | jq -r '.usage // ""')"
  local expire="$(echo "${1}" | jq -r '.expire // ""')"
  local output_file="$(mktemp)"
  set -x
  gpg --homedir "${home_dir}" --batch --no-tty \
      --status-fd 1  --passphrase "${passphrase}" \
      --quick-generate-key "${uid}" "${algo}" "${usage}" "${expire}" >"${output_file}" 2>&1
  set +x
  local fingerprint="$(awk '/KEY_CREATED P/ { print $4}' "${output_file}")"
  local revocation_cert_path="$(awk '/revocation/ { print substr($6, 2, length($6)-2) }' "${output_file}")"
  rm -f "${output_file}"
  cat <<-EOF
  {"fingerprint": "${fingerprint}",
   "uid": "${uid}",
   "algo": "${algo}",
   "revocationCertPath": "${revocation_cert_path}",
   "passphrase": "${passphrase}",
   "home_dir": "${home_dir}"}
EOF
}

function add_subkey() {
  local home_dir="$(echo "${1}" | jq -r '.home_dir')"
  local passphrase="$(echo "${1}" | jq -r '.passphrase')"
  local master_fpr="$(echo "${1}" | jq -r '.fingerprint')"
  local algo="$(echo "${2}" | jq -r '.algo')"
  local usage="$(echo "${2}" | jq -r '.usage')"
  local expire="$(echo "${2}" | jq -r '.expire')"
  local output_file="$(mktemp)"
  set -x
  gpg --homedir "${home_dir}" --batch \
      --status-fd 1 --pinentry-mode loopback --passphrase "${passphrase}" \
      --quick-add-key "${master_fpr}" "${algo}" "${usage}" "${expire}" >"${output_file}" 2>&1
  set +x
  local fingerprint="$(awk '/KEY_CREATED S/ { print $4}' "${output_file}")"
  rm -f "${output_file}"
  cat <<-EOF
  {"usage": "${usage}",
   "algo": "${algo}",
   "fingerprint": "${fingerprint}"}
EOF
}

function add_uid() {
  local home_dir="$(echo "${1}" | jq -r ".home_dir // \"${GNUPGHOME}\"")"
  local passphrase="$(echo "${1}" | jq -r '.passphrase')"
  local master_fpr="$(echo "${1}" | jq -r '.fingerprint')"
  local uid="$(echo "${2}" | jq -r '.uid')"
  local output_file="$(mktemp)"
  set -x
  gpg --homedir "${home_dir}" --batch \
      --status-fd 1 --pinentry-mode loopback --passphrase "${passphrase}" \
      --quick-add-uid "${master_fpr}" "${uid}" >"${output_file}" 2>&1
  set +x
  rm -f "${output_file}"
}

function set_primary_uid() {
  local home_dir="$(echo "${1}" | jq -r ".home_dir // \"${GNUPGHOME}\"")"
  local master_fpr="$(echo "${1}" | jq -r '.fingerprint')"
  local passphrase="$(echo "${1}" | jq -r '.passphrase')"
  local uid="$(echo "${2}" | jq -r '.uid')"
  local output_file="$(mktemp)"
  set -x
  gpg --homedir "${home_dir}" --batch \
      --status-fd 1 --pinentry-mode loopback --passphrase "${passphrase}" \
      --quick-set-primary-uid "${master_fpr}" "${uid}" >"${output_file}" 2>&1
  set +x
  rm -f "${output_file}"
}

function demo() {
  unset GNUPGHOME
  local gnupg_home="$(mktemp -d)"

  # create master key (cert only)
  local master_key_params="$(echo '{"uid": "Grzegorz Rynkowski", "algo": "rsa2048", "usage": "cert", "expire": "2090-01-01"}' \
    | jq --arg home "${gnupg_home}" '. += {"home_dir": $home}')"
  local master_key_info="$(gen_master_key "${master_key_params}")"

  # create subkeys
  local subkey_1_info="$(add_subkey "${master_key_info}" '{"algo": "rsa2048", "usage": "encrypt", "expire": "1y"}')"
  local subkey_2_info="$(add_subkey "${master_key_info}" '{"algo": "rsa2048", "usage": "sign",    "expire": "1y"}')"
  local subkey_3_info="$(add_subkey "${master_key_info}" '{"algo": "rsa2048", "usage": "auth",    "expire": "1y"}')"
  # add uids
  add_uid "${master_key_info}" '{"uid": "Grzegorz Rynkowski <[email protected]>"}'
  add_uid "${master_key_info}" '{"uid": "Grzegorz Rynkowski <[email protected]>"}'
  set_primary_uid "${master_key_info}" '{"uid": "[email protected]"}'

  printf "\n${YELLOW}${BOLD}%s${RESET}\n%s\n" "MASTER" "${master_key_info}"
  printf "\n${YELLOW}${BOLD}%s${RESET}\n%s\n" "SUBKEY_1" "${subkey_1_info}"
  printf "\n${YELLOW}${BOLD}%s${RESET}\n%s\n" "SUBKEY_2" "${subkey_2_info}"
  printf "\n${YELLOW}${BOLD}%s${RESET}\n%s\n" "SUBKEY_3" "${subkey_3_info}"

  printf "\n${YELLOW}${BOLD}%s${RESET}\n" "LIST OF KEYS"
  gpg --homedir "${gnupg_home}" --list-secret-keys

  printf "%s\n" "-- FILES SAVED in GNUPGHOME=${gnupg_home}:"
  tree "${gnupg_home}"

  rm -rf "${gnupg_home}"
  set +x
}

demo