clevis/src/luks/systemd/clevis-luks-askpass

#!/bin/bash -e
# vim: set tabstop=8 shiftwidth=4 softtabstop=4 expandtab smarttab colorcolumn=80:
#
# Copyright (c) 2016 Red Hat, Inc.
# Author: Harald Hoyer <harald@redhat.com>
# 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/>.
#

UUID=cb6e8904-81ff-40da-a84a-07ab9ab5715e

shopt -s nullglob

path=/run/systemd/ask-password
while getopts ":lp:" o; do
    case "$o" in
    l) loop=true;;
    p) path="$OPTARG";;
    esac
done

luks1_decrypt() {
    luksmeta load "$@" \
        | clevis decrypt

    local rc
    for rc in "${PIPESTATUS[@]}"; do
        [ $rc -eq 0 ] || return $rc
    done
    return 0
}

luks2_jwe() {
    # jose jwe fmt -c outputs extra \n, so clean it up
    cryptsetup token export "$@" \
        | jose fmt -j- -Og jwe -o- \
        | jose jwe fmt -i- -c \
        | tr -d '\n'

    local rc
    for rc in "${PIPESTATUS[@]}"; do
        [ $rc -eq 0 ] || return $rc
    done
    return 0
}

while true; do
    todo=0

    for question in "$path"/ask.*; do
        metadata=false
        unlocked=false
        d=
        s=

        while read line; do
            case "$line" in
                Id=cryptsetup:*) d="${line##Id=cryptsetup:}";;
                Socket=*) s="${line##Socket=}";;
            esac
        done < "$question"

        [ "$d" ] && [ "$s" ] || continue

        if cryptsetup isLuks --type luks1 "$d"; then
            # If the device is not initialized, sliently skip it.
            luksmeta test -d "$d" || continue

            while read -r slot state uuid; do
                [ "$state" == "active" ] || continue
                [ "$uuid" == "$UUID" ] || continue
                metadata=true

                if pt="$(luks1_decrypt -d "$d" -s "$slot" -u "$UUID")"; then
                    echo -n "+$pt" | ncat -U -u --send-only "$s"
                    unlocked=true
                    break
                fi
            done < <(luksmeta show -d "$d")
        elif cryptsetup isLuks --type luks2 "$d"; then
            while read -r id; do
                jwe="$(luks2_jwe --token-id "$id" "$d")" \
                    || continue
                metadata=true

                if pt="$(echo -n "$jwe" | clevis decrypt)"; then
                    echo -n "+$pt" | ncat -U -u --send-only "$s"
                    unlocked=true
                    break
                fi
            done < <(cryptsetup luksDump "$d" | sed -rn 's|^\s+([0-9]+): clevis|\1|p')
        fi

        [ "$metadata" == true ] || continue
        [ "$unlocked" == true ] && continue
        ((todo++))
    done

    if [ $todo -eq 0 ] || [ "$loop" != true ]; then
        break;
    fi

    sleep 0.5
done