heads/initrd/bin/kexec-save-key

#!/bin/bash
# Generate a TPM key used to unlock LUKS disks

. /etc/functions

TRACE "kexec-save-key: start"
set -e -o pipefail
. /etc/functions

lvm_volume_group=""
skip_sign="n"
while getopts "sp:d:l:" arg; do
	case $arg in
	s) skip_sign="y" ;;
	p) paramsdir="$OPTARG" ;;
	d) paramsdev="$OPTARG" ;;
	l) lvm_volume_group="$OPTARG" ;;
	esac
done

DEBUG "kexec-save-key prior of parsing: paramsdir: $paramsdir, paramsdev: $paramsdev, lvm_volume_group: $lvm_volume_group"

shift $(expr $OPTIND - 1)
key_devices="$@"

DEBUG "kexec-save-key: key_devices: $key_devices"

if [ -z "$paramsdir" ]; then
	die "Usage: $0 [-s] -p /boot [-l qubes_dom0] [/dev/sda2 /dev/sda5 ...] "
fi

if [ -z "$paramsdev" ]; then
	paramsdev="$paramsdir"
	DEBUG "kexec-save-key: paramsdev modified to : $paramsdev"
fi

paramsdev="${paramsdev%%/}"
paramsdir="${paramsdir%%/}"

DEBUG "kexec-save-key prior of last override: paramsdir: $paramsdir, paramsdev: $paramsdev, lvm_volume_group: $lvm_volume_group"

if [ -n "$lvm_volume_group" ]; then
	lvm vgchange -a y $lvm_volume_group ||
		die "Failed to activate the LVM group"
	#TODO: why reuse key_devices for lvm devices?
	for dev in /dev/$lvm_volume_group/*; do
		key_devices="$key_devices $dev"
	done
fi

if [ -z "$key_devices" ]; then
	die "No devices specified for TPM key insertion"
fi

# try to switch to rw mode
mount -o rw,remount $paramsdev

rm -f $paramsdir/kexec_key_lvm.txt || true
if [ -n "$lvm_volume_group" ]; then
	DEBUG "kexec-save-key saving under $paramsdir/kexec_key_lvm.txt : lvm_volume_group: $lvm_volume_group"
	echo "$lvm_volume_group" >$paramsdir/kexec_key_lvm.txt ||
		die "Failed to write lvm group to key config "
fi

rm -f $paramsdir/kexec_key_devices.txt || true
for dev in $key_devices; do
	DEBUG "Getting UUID for $dev"
	uuid=$(cryptsetup luksUUID "$dev" 2>/dev/null) ||
		die "Failed to get UUID for device $dev"
	DEBUG "Saving under $paramsdir/kexec_key_devices.txt : dev: $dev, uuid: $uuid"
	echo "$dev $uuid" >>$paramsdir/kexec_key_devices.txt ||
		die "Failed to add $dev:$uuid to key devices config"
done

kexec-seal-key $paramsdir ||
	die "Failed to save and generate key in TPM"

if [ "$skip_sign" != "y" ]; then
	extparam=
	if [ "$CONFIG_IGNORE_ROLLBACK" != "y" ]; then
		extparam=-r
	fi
	# sign and auto-roll config counter
	kexec-sign-config -p $paramsdir $extparam ||
		die "Failed to sign updated config"
fi

# switch back to ro mode
mount -o ro,remount $paramsdev