#!/bin/sh
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=4 sw=4 sts=0 et filetype=sh
command -v ask_for_password >/dev/null || . /lib/dracut-crypt-lib.sh
# loop_decrypt mnt_point keypath keydev device
#
# Decrypts symmetrically encrypted key to standard output.
#
# mnt_point - mount point where <keydev> is already mounted
# keypath - LUKS encrypted loop file path relative to <mnt_point>
# keydev - device on which key resides; only to display in prompt
# device - device to be opened by cryptsetup; only to display in prompt
loop_decrypt() {
local mntp="$1"
local keypath="$2"
local keydev="$3"
local device="$4"
local key="/dev/mapper/${mntp##*/}"
if [ ! -b $key ]; then
info "Keyfile has .img suffix, treating it as LUKS-encrypted loop keyfile container to unlock $device"
local loopdev=$(losetup -f "${mntp}/${keypath}" --show)
local opts="-d - luksOpen $loopdev ${key##*/}"
ask_for_password \
--cmd "cryptsetup $opts" \
--prompt "Password ($keypath on $keydev for $device)" \
--tty-echo-off
[ -b $key ] || die "Tried setting it up, but keyfile block device was still not found!"
initqueue --onetime --finished --unique --name "crypt-loop-cleanup-10-${key##*/}" \
$(command -v cryptsetup) "luksClose $key"
initqueue --onetime --finished --unique --name "crypt-loop-cleanup-20-${loopdev##*/}" \
$(command -v losetup) "-d $loopdev"
else
info "Existing keyfile found, re-using it for $device"
fi
cat $key
}