Files
CISS.debian.live.builder/config/includes.chroot/usr/lib/live/boot/0024-ciss-crypt-squash
2025-11-19 16:21:33 +00:00

172 lines
5.9 KiB
Bash

#!/bin/sh
# bashsupport disable=BP5007
# shellcheck disable=SC2249
# shellcheck shell=sh
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-11-12; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.live.builder.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.live.builder
# SPDX-Security-Contact: security@coresecret.eu
# Purpose: Open /live/ciss_rootfs.crypt (LUKS) and present its SquashFS as /run/live/rootfs
# Phase : premount (executed by live-boot inside the initramfs)
set -eu
printf "\e[95m[INFO] Starting: [/usr/lib/live/boot/0024-ciss-crypt-squash] ... \n\e[0m"
#######################################
# Premount logging helper.
# Globals:
# None
# Arguments:
# *: String to log.
#######################################
log() {
msg="$*"
if [ -w /dev/kmsg ]; then
printf '<6>%s: %s\n' '0024-ciss-crypt-squash' "${msg}" > /dev/kmsg
else
printf '%s: %s\n' '0024-ciss-crypt-squash' "${msg}"
fi
}
### Declare variables. ---------------------------------------------------------------------------------------------------------
export CDLB_ISO_LABEL="CISS.debian.live"
export CDLB_LUKS_FS="/live/ciss_rootfs.crypt"
export CDLB_MAPPER_NAME="ciss_rootfs.crypt"
MNT_MEDIUM="/run/live/medium"
MNT_ROOTFS="/run/live/rootfs"
_PARAMETER=""
_dev=""
### Read the kernel cmdline once. ----------------------------------------------------------------------------------------------
CMDLINE="$(cat /proc/cmdline 2>/dev/null || printf '')"
for _PARAMETER in ${CMDLINE}; do
case "${_PARAMETER}" in
ciss_crypt_path=*) export CDLB_LUKS_FS="${_PARAMETER#ciss_crypt_path=}";;
ciss_iso_label=* ) export CDLB_ISO_LABEL="${_PARAMETER#ciss_iso_label=}";;
esac
done
printf "\e[92m[INFO] CDLB_LUKS_FS : [%s] \n\e[0m" "${CDLB_LUKS_FS}"
printf "\e[92m[INFO] CDLB_ISO_LABEL : [%s] \n\e[0m" "${CDLB_ISO_LABEL}"
mkdir -p "${MNT_MEDIUM}" "${MNT_ROOTFS}"
### Mount the live medium (ISO) read-only, unless already mounted. -------------------------------------------------------------
if ! mountpoint -q "${MNT_MEDIUM}"; then
if [ -n "${CDLB_ISO_LABEL}" ] && [ -e "/dev/disk/by-label/${CDLB_ISO_LABEL}" ]; then
mount -r -t iso9660 "/dev/disk/by-label/${CDLB_ISO_LABEL}" "${MNT_MEDIUM}" 2>/dev/null \
|| mount -r -t udf "/dev/disk/by-label/${CDLB_ISO_LABEL}" "${MNT_MEDIUM}" 2>/dev/null \
|| log "could not mount label=${CDLB_ISO_LABEL} (iso9660/udf)"
fi
fi
if ! mountpoint -q "${MNT_MEDIUM}"; then
### Fallback scan (covers SR drives and loop-mounted ISOs that udev exposed).
for _dev in /dev/sr* /dev/cdrom /dev/disk/by-label/*; do
### Skip non-block entries early.
[ -b "${_dev}" ] || continue
### Try ISO9660 first, then UDF; only unmount on failure.
if mount -r -t iso9660 "${_dev}" "${MNT_MEDIUM}" 2>/dev/null || mount -r -t udf "${_dev}" "${MNT_MEDIUM}" 2>/dev/null; then
mountpoint -q "${MNT_MEDIUM}" 2>/dev/null && break
else
umount "${MNT_MEDIUM}" 2>/dev/null || true
fi
done
fi
if ! mountpoint -q "${MNT_MEDIUM}"; then
log "No live medium mounted, defer to default live-boot path."
printf "\e[91m[FATAL] No live medium mounted, defer to default live-boot path. \n\e[0m"
exit 0
fi
printf "\e[92m[INFO] MNT_MEDIUM : [%s] \n\e[0m" "${MNT_MEDIUM}"
### Locate the encrypted root container on the medium. -------------------------------------------------------------------------
if [ ! -f "${MNT_MEDIUM}/${CDLB_LUKS_FS}" ]; then
log "Encrypted root not found at: [${MNT_MEDIUM}/${CDLB_LUKS_FS}]"
printf "\e[91m[FATAL] Encrypted root not found at: [%s/%s] \n\e[0m" "${MNT_MEDIUM}" "${CDLB_LUKS_FS}"
exit 0
fi
printf "\e[92m[INFO] CISS LUKS FS : [%s/%s] \n\e[0m" "${MNT_MEDIUM}" "${CDLB_LUKS_FS}"
### Create/read FIFO compatible with cryptsetup-initramfs. This allows 'cryptroot-unlock' to feed the passphrase over SSH. -----
mkdir -p /lib/cryptsetup
[ -p /lib/cryptsetup/passfifo ] || mkfifo /lib/cryptsetup/passfifo
### Attach a loop device read-only to the encrypted file. ----------------------------------------------------------------------
LOOP="$(losetup -f --show -r "${MNT_MEDIUM}/${CDLB_LUKS_FS}")" || { log "losetup failed"; exit 42; }
### Try to open the LUKS container, first via FIFO (SSH unlock), then interactively. -------------------------------------------
attempts=0
while true; do
attempts=$((attempts+1))
printf "\e[93m[INFO] Unlock: [%s] Attempt: [%s] Use 'cryptroot-unlock' over SSH or enter on console: \n\e[0m" \
"${CDLB_LUKS_FS}" "${attempts}" >/dev/console 2>/dev/null || true
### Non-blocking read from FIFO (Dropbear and cryptroot-unlock path). --------------------------------------------------------
if timeout 5 cat /lib/cryptsetup/passfifo | cryptsetup open --type luks --readonly "${LOOP}" crypt_liveiso --key-file - 2>/dev/null; then
break
fi
### Interactive fallback on the console. -------------------------------------------------------------------------------------
if cryptsetup open --type luks --readonly "${LOOP}" crypt_liveiso; then
break
fi
done
### Expose the decrypted root device for live-boot overlay. The live-boot components will pick this up in '9990-overlay.sh'. ---
echo "/dev/mapper/crypt_liveiso" >| /run/ciss-rootdev
chmod 0644 /run/ciss-rootdev 2>/dev/null || true
export CISS_ROOT_DEV="/dev/mapper/crypt_liveiso"
export CISS_ROOT_DIR=""
log "Decrypted root device exposed at [/run/ciss-rootdev] -> [/dev/mapper/crypt_liveiso]"
printf "\e[92m[INFO] Decrypted root device exposed at: [/run/ciss-rootdev] -> [/dev/mapper/crypt_liveiso] \n\e[0m"
printf "\e[92m[INFO] Successfully applied: [/usr/lib/live/boot/0024-ciss-crypt-squash] \n\e[0m"
# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh