#!/bin/sh
# Copyright (C) 2013-2016 Sören Tempel
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

umask 077

##
# Variables
##

GPG_OPTS="--quiet --yes --batch"
STORE_DIR="${PASSWORD_STORE_DIR:-${HOME}/.password-store}"

if [ -r "${STORE_DIR}/.gpg-id" ] && [ -z "${PASSWORD_STORE_KEY}" ]; then
  read -r PASSWORD_STORE_KEY < "${STORE_DIR}/.gpg-id"
fi

##
# Helper
##

abort() {
  printf '%s\n' "${1}" 1>&2
  exit 1
}

gpg() {
  if [ -n "${PASSWORD_STORE_KEY}" ]; then
    gpg2 $GPG_OPTS --recipient "${PASSWORD_STORE_KEY}" "$@"
  else
    gpg2 $GPG_OPTS --default-recipient-self "$@"
  fi
}

readpw() {
  if [ -t 0 ]; then
    printf "%s" "${1}"
    stty -echo
  fi

  IFS= read -r "${2}"
  [ -t 0 ] && stty echo
}

##
# Commands
##

show() {
  entry_name="${1}"
  entry_path="${STORE_DIR}/${entry_name}.gpg"

  if [ -z "${entry_name}" ]; then
    abort "USAGE: tpm show ENTRY"
  fi

  if [ ! -e "${entry_path}" ]; then
    abort "The requested entry doesn't exist."
  fi

  gpg --decrypt "${entry_path}"
}

insert() {
  entry_name="${1}"
  entry_path="${STORE_DIR}/${entry_name}.gpg"

  if [ -z "${entry_name}" ]; then
    abort "USAGE: tpm insert ENTRY"
  fi

  if [ -e "${entry_path}" ]; then
    abort "This entry already exists, please remove it first."
  fi

  password=""
  readpw "Password for '${entry_name}': " password
  if [ -t 0 ]; then
    printf '\n'
  fi

  if [ -z "${password}" ]; then
    abort "You didn't specify a password."
  fi

  mkdir -p "${entry_path%/*}"
  printf '%s\n' "${password}" | gpg --encrypt \
    --output "${entry_path}"
}

##
# Parse input
##

if [ $# -gt 2 ]; then
  abort "tpm doesn't accept more than two arguments."
fi

case "${1}" in
  "show")   show   "${2}" ;;
  "insert") insert "${2}" ;;
  *) abort "USAGE: tpm COMMAND ENTRY" ;;
esac

# vim: et:sw=2:sts=2
