#!/bin/bash
#
# Copyright (C) 2009 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Generates a public/private key pair suitable for use in signing
# android .apks and OTA update packages.

if [ "$#" -lt 2 -o "$#" -gt 3 ]; then
  cat <<EOF
Usage: $0 <name> <subject> [<keytype>]

Creates <name>.pk8 key and <name>.x509.pem cert.  Cert contains the
given <subject>. A keytype of "rsa" or "ec" is accepted.
EOF
  exit 2
fi

if [[ -e $1.pk8 || -e $1.x509.pem ]]; then
  echo "$1.pk8 and/or $1.x509.pem already exist; please delete them first"
  echo "if you want to replace them."
  exit 1
fi

# Use named pipes to connect get the raw RSA private key to the cert-
# and .pk8-creating programs, to avoid having the private key ever
# touch the disk.

tmpdir=$(mktemp -d)
trap 'rm -rf ${tmpdir}; echo; exit 1' EXIT INT QUIT

one=${tmpdir}/one
two=${tmpdir}/two
mknod ${one} p
mknod ${two} p
chmod 0600 ${one} ${two}

read -p "Enter password for '$1' (blank for none; password will be visible): " \
  password

if [ "${3}" = "rsa" -o "$#" -eq 2 ]; then
  ( openssl genrsa -f4 4096 | tee ${one} > ${two} ) &
  hash="-sha256"
elif [ "${3}" = "ec" ]; then
  ( openssl ecparam -name prime256v1 -genkey -noout | tee ${one} > ${two} ) &
  hash="-sha256"
else
  echo "Only accepts RSA or EC keytypes."
  exit 1
fi

openssl req -new -x509 ${hash} -key ${two} -out $1.x509.pem \
  -days 10000 -subj "$2" &

if [ "${password}" == "" ]; then
  echo "creating ${1}.pk8 with no password"
  openssl pkcs8 -in ${one} -topk8 -outform DER -out $1.pk8 -nocrypt
else
  echo "creating ${1}.pk8 with password [${password}]"
  export password
  openssl pkcs8 -in ${one} -topk8 -v1 PBE-SHA1-3DES -outform DER -out $1.pk8 \
    -passout env:password
  unset password
fi

wait
wait