clevis/src/luks/clevis-luks-unlock

#!/bin/bash -e
# vim: set tabstop=8 shiftwidth=4 softtabstop=4 expandtab smarttab colorcolumn=80:
#
# Copyright (c) 2016 Red Hat, Inc.
# Author: Nathaniel McCallum <npmccallum@redhat.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
. clevis-luks-common-functions

SUMMARY="Unlocks a LUKS volume"

function usage() {
    exec >&2
    echo
    echo "Usage: clevis luks unlock -d DEV [-n NAME] [-t SLT]"
    echo
    echo "$SUMMARY":
    echo
    echo "  -d DEV  The LUKS device on which to perform unlocking"
    echo
    echo "  -n NAME The name of the unlocked device node"
    echo
    echo "  -t SLT Test the passphrase for the given slot without unlocking"
    echo "         the device"
    echo
    exit 2
}

if [ $# -eq 1 ] && [ "$1" == "--summary" ]; then
    echo "$SUMMARY"
    exit 0
fi

while getopts ":d:n:t:" o; do
    case "$o" in
    d) DEV="$OPTARG";;
    n) NAME="$OPTARG";;
    t) SLT="$OPTARG";;
    *) usage;;
    esac
done

if [ -z "$DEV" ]; then
    echo "Did not specify a device!" >&2
    usage
fi

if ! cryptsetup isLuks "$DEV"; then
    echo "$DEV is not a LUKS device!" >&2
    exit 1
fi

NAME="${NAME:-luks-"$(cryptsetup luksUUID "$DEV")"}"

if [ -n "$SLT" ]; then
    if ! clevis_luks_unlock_device_by_slot "${DEV}" "${SLT}" >/dev/null; then
        echo "Test for token slot ${SLT} on device ${DEV} failed." >&2
        exit 1
    fi
else
    if ! pt=$(clevis_luks_unlock_device "${DEV}"); then
        echo "${DEV} could not be opened." >&2
        exit 1
    fi

    echo -n "${pt}" | cryptsetup open -d- "${DEV}" "${NAME}"
fi