#!/bin/sh

# abuild-sign - sign indexes
# Copyright (c) 2009 Natanael Copa <ncopa@alpinelinux.org>
#
# Distributed under GPL-2.0-only
#

program_version=@VERSION@
sharedir=${ABUILD_SHAREDIR:-@sharedir@}

if ! [ -f "$sharedir/functions.sh" ]; then
	echo "$sharedir/functions.sh: not found" >&2
	exit 1
fi
. "$sharedir/functions.sh"

gzip=$(command -v pigz || echo gzip)

do_sign() {
	local f i keyname repo openssl
	openssl=$(command -v openssl || echo libressl)

	# we are actually only interested in the name, not the file itself
	keyname=${pubkey##*/}

	for f; do
		i=$(readlink -f $f)
		[ -d "$i" ] && i="$i/APKINDEX.tar.gz"
		repo="${i%/*}"
		trap 'die "failed to sign $i"' EXIT
		set -e
		cd "$repo"
		sig=".SIGN.$sigtype.$keyname"
		$openssl dgst $dgstargs -sign "$privkey" -out "$sig" "$i"

		if [ -n "$SOURCE_DATE_EPOCH" ]; then
			touch -h -d "@$SOURCE_DATE_EPOCH" "$sig"
		fi

		tmptargz=$(mktemp)
		tar --owner=0 --group=0 --numeric-owner -f - -c "$sig" | abuild-tar --cut | $gzip -n -9 > "$tmptargz"
		tmpsigned=$(mktemp)
		cat "$tmptargz" "$i" > "$tmpsigned"
		rm -f "$tmptargz" "$sig"
		chmod 644 "$tmpsigned"
		mv "$tmpsigned" "$i"
		msg "Signed $i"
		set +e
		trap - EXIT
	done
}

usage() {
	cat <<-__EOF__
		$program $program_version - sign indexes
		Usage: $program [-k PRIVKEY] [-p PUBKEY] INDEXFILE...
		       $program -e
		Options:
		  -e, --installed    Check only of there exist a private key for signing
		  -k, --private KEY  The private key to use for signing
		  -p, --public KEY   The name of public key. apk add will look for
		                     /etc/apk/keys/KEY
		  -t, --type TYPE    The signature type RSA or RSA256
		  -q, --quiet
		  -h, --help         Show this help

	__EOF__
}

check_installed=false
privkey="$PACKAGER_PRIVKEY"
pubkey=
quiet=

args=$(getopt -o ek:p:t:qh --long installed,private:,public:,type:,quiet,help -n "$program" -- "$@")
if [ $? -ne 0 ]; then
	usage >&2
	exit 2
fi
eval set -- "$args"
while true; do
	case $1 in
		-e|--installed) check_installed=true;;
		-k|--private) privkey=$2; shift;;
		-p|--public) pubkey=$2; shift;;
		-t|--type) sigtype=$2; shift;;
		-q|--quiet) quiet=1;; # suppresses msg
		-h|--help) usage; exit;;
		--) shift; break;;
		*) exit 1;; # getopt error
	esac
	shift
done
if [ $# -eq 0 ] && ! $check_installed; then
	usage >&2
	exit 2
fi

if [ -z "$privkey" ]; then
	cat >&2 <<-__EOF__
		No private key found. Use 'abuild-keygen' to generate the keys.
		Then you can either:
		  * set the PACKAGER_PRIVKEY in $ABUILD_USERCONF
		    ('abuild-keygen -a' does this for you)
		  * set the PACKAGER_PRIVKEY in $ABUILD_CONF
		  * specify the key with the -k option to $program

	__EOF__
	exit 1
fi

if [ -z "$pubkey" ]; then
	pubkey=${PACKAGER_PUBKEY:-"${privkey}.pub"}
fi

if [ -z "$sigtype" ]; then
	sigtype=RSA
fi

case $sigtype in
	RSA) dgstargs="-sha1";;
	RSA256) dgstargs="-sha256";;
	*)
		echo "$program: supported types are RSA and RSA256" >&2
		exit 1
		;;
esac
if $check_installed; then
	if ! [ -e "$privkey" ]; then
		echo "$program: $privkey: File not found" >&2
		exit 1
	fi
	if ! [ -e "$pubkey" ]; then
		echo "$program: $pubkey: File not found" >&2
		exit 1
	fi
else
	do_sign "$@"
fi