protonkey/protonkey

#!/bin/sh

# Copyright (c) 2022 Emma Tebibyte
# SPDX-License-Identifier: AGPL-3.0-or-later
#
# Protonkey is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published by the
# Free Software Foundation, either version 3 of the License, or (at your
# option) any later version.
# 
# Protonkey 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 Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see https://www.gnu.org/licenses/.

if test -z "$1"; then
  printf "Usage: %s [ProtonMail address]\n" "$0" 1>&2
  exit 64 # syexits(3) EX_USAGE
fi

for command in \
  curl \
  gpg
do
  if ! command -v "$command" > /dev/null; then
    printf "%s: Missing dependency: %s(1)\n" "$0" "$command" 1>&2
    exit 69 # sysexits(3) EX_UNAVAILABLE
  fi
done

URL="https://api.protonmail.ch/pks/lookup?op=get&search=$1"
RESPONSE="$(curl -s "$URL")"

if [ "$RESPONSE" = 'No key found' ]; then
  printf "%s\n" "$RESPONSE" 1>&2
  exit 76 # sysexits(3) EX_PROTOCOL
else
  printf "%s\n" "$RESPONSE"
  exit 0
fi