#!/bin/sh
# Sign a valid directory of kexec params
set -e -o pipefail
. /etc/functions

rollback="n"
update_counter="n"
while getopts "p:c:u" arg; do
	case $arg in
		p) paramsdir="$OPTARG" ;;
		c) counter="$OPTARG"; rollback="y" ;;
		u) update_counter="y"; rollback="y" ;;
	esac
done

if [ -z "$paramsdir" ]; then
	die "Usage: $0 -p /boot/ [ -u | -c counter ]"
fi

confirm_gpg_card

if [ "$rollback" = "y" ]; then
	rollback_file="$paramsdir/kexec_rollback.txt"

	if [ -n "$counter" ]; then
		# use existing counter
		read_tpm_counter $counter \
		|| die "$paramsdir: Unable to read tpm counter '$counter'"
	else
		# increment counter
		check_tpm_counter $rollback_file \
		|| die "$paramsdir: Unable to find/create tpm counter"
		counter="$TPM_COUNTER"

		increment_tpm_counter $counter \
		|| die "$paramsdir: Unable to increment tpm counter"
	fi

	sha256sum /tmp/counter-$counter > $rollback_file \
	|| die "$paramsdir: Unable to create rollback file"
fi

param_files=`find $paramsdir/kexec*.txt`
if [ -z "$param_files" ]; then
	die "$paramsdir: No kexec parameter files to sign"
fi

for tries in 1 2 3; do
	if sha256sum $param_files | gpg \
		--digest-algo SHA256 \
		--detach-sign \
		-a \
		> $paramsdir/kexec.sig \
	; then
		exit 0
	fi
done

die "$paramsdir: Unable to sign kexec hashes"