Files
CISS.debian.live.builder/config/includes.chroot/etc/initramfs-tools/files/unlock_wrapper.sh
Marc S. Weidner 08a0291f16
All checks were successful
🛡️ Shell Script Linting / 🛡️ Shell Script Linting (push) Successful in 50s
V8.13.536.2025.12.04
Signed-off-by: Marc S. Weidner <msw@coresecret.dev>
2025-12-04 09:36:33 +01:00

434 lines
12 KiB
Bash

#!/bin/bash
# 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: LicenseRef-CNCL-1.1 OR LicenseRef-CCLA-1.1
# 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
# SPDX-Comment: unlock_wrapper.sh to be executed as 'dropbear-initramfs' SSH forced command.
# shellcheck disable=SC2034
set -Ceu -o pipefail -o ignoreeof
shopt -s failglob
shopt -s lastpipe
shopt -u nullglob
umask 0077
declare -g PATH="/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr"
### Will be replaced at build time:
declare -gr CDLB_DB_EXP_FPR="@EXP_FPR@"
declare -gr CDLB_DB_EXP_CA_FPR="@EXP_CA_FPR@"
declare -gr CDLB_MAPPER_NAME="crypt_liveiso"
declare -gr CDLB_MAPPER_DEV="/dev/mapper/${CDLB_MAPPER_NAME}"
#######################################
# Variable declaration
#######################################
# shellcheck disable=SC2016
declare -r REGEX='^\$6\$(rounds=([1-9][0-9]{3,8})\$)?([./A-Za-z0-9]{1,16})\$([./A-Za-z0-9]{86})$'
# shellcheck disable=SC2155
declare -r CURRENTDATE=$(date +"%F %T")
declare -g ERRTRAP='false'
declare -r GRE='\e[0;92m'
declare -r MAG='\e[0;95m'
declare -r RED='\e[0;91m'
declare -r RES='\e[0m'
declare -r NL='\n'
declare -g PASSPHRASE=''
#######################################
# Read passphrase strictly from STDIN (SSH channel), not '/dev/console'.
# Arguments:
# 1: Prompt to print on terminal
# 2: Variable name to capture passphrase
#######################################
ask_via_stdin() {
declare -r prompt="$1"
declare -r varname="$2"
### Prompt to STDERR so pipes don't capture it.
printf "%s" "${prompt}" >&2
### Silent, canonical read from FD 0 (SSH channel when forced-command).
IFS= read -r -s "${varname?}" <&0
printf "\n" >&2
return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f ask_via_stdin
#######################################
# Printed text in color.
# Arguments:
# 1: Color code.
# *: Text to print.
#######################################
color_echo() { declare c="${1}"; shift; declare msg="${*}"; printf "%b%s %b%b" "${c}" "${msg}" "${RES}" "${NL}"; return 0; }
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f color_echo
#######################################
# Die Helper: print and then exit hard.
# Globals:
# NC
# RED
# Arguments:
# 1: Message string to print.
#######################################
die() { printf "%b✘ %s %b%b" "${RED}" "$1" "${RES}" "${NL}" >&2; power_off 3; }
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f die
#######################################
# Drop into the bash environment.
# Arguments:
# None
#######################################
drop_bash() { stty echo 2>/dev/null || true; prompt_string; exec /bin/bash -i; }
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f drop_bash
#######################################
# Unified power-off routine.
# Arguments:
# 1: Sleep time before power-off in seconds (Default to 0 seconds).
#######################################
power_off() {
declare -r wait="${1:-0}"
sleep "${wait}"
sync
echo 1 >| /proc/sys/kernel/sysrq
echo o >| /proc/sysrq-trigger
### The System powers off immediately; no further code is executed.
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f power_off
#######################################
# Print Error Message for Trap on 'ERR' on Terminal.
# Globals:
# NL
# RED
# Arguments:
# 1: ${?}
# 2: ${BASH_SOURCE[0]}
# 3: ${LINENO}
# 4: ${FUNCNAME[0]:-main}
# 5: ${BASH_COMMAND}
#######################################
print_scr_err() {
declare -r scr_err_errcode="$1"
declare -r scr_err_errscrt="$2"
declare -r scr_err_errline="$3"
declare -r scr_err_errfunc="$4"
declare -r scr_err_errcmmd="$5"
printf "%b" "${NL}" >&2
color_echo "${RED}" "✘ System caught an 'ERROR'. System Power Off in 16 seconds." >&2
printf "%b" "${NL}" >&2
color_echo "${RED}" "✘ Error : [${scr_err_errcode}]" >&2
color_echo "${RED}" "✘ Line : [${scr_err_errline}]" >&2
color_echo "${RED}" "✘ Script : [${scr_err_errscrt}]" >&2
color_echo "${RED}" "✘ Function : [${scr_err_errfunc}]" >&2
color_echo "${RED}" "✘ Command : [${scr_err_errcmmd}]" >&2
printf "%b" "${NL}" >&2
return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f print_scr_err
#######################################
# Print Error Message for '0'-Exit-Code on Terminal.
# Globals:
# GRE
# Arguments:
# None
#######################################
print_scr_scc() { color_echo "${GRE}" "✅ Script exited successfully. Proceeding with booting."; sleep 3; }
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f print_scr_scc
#######################################
# Generates an informative shell prompt.
# Globals:
# PS1
# Arguments:
# None
#######################################
prompt_string() {
declare -gx PS1="\
\[\033[1;91m\]\d\[\033[0m\]|\[\033[1;91m\]\u\[\033[0m\]@\
\[\033[1;95m\]\h\[\033[0m\]:\
\[\033[1;96m\]\w\[\033[0m\]/>>\
\$(if [[ \$? -eq 0 ]]; then \
# Show exit status in green if zero
echo -e \"\[\033[1;92m\]\$?\[\033[0m\]\"; \
else \
# Show exit status in red otherwise
echo -e \"\[\033[1;91m\]\$?\[\033[0m\]\"; \
fi)\
|~\$ "
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f prompt_string
#######################################
# Read the passphrase interactively.
# Globals:
# PASSPHRASE
# Arguments:
# None
# Returns:
# 0: on success
#######################################
read_passphrase() {
### Read from SSH STDIN (or TTY fallback), never via '/lib/cryptsetup/askpass'.
ask_via_stdin "Enter passphrase: " PASSPHRASE
return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f read_passphrase
#######################################
# Securely unset the 'PASSPHRASE'-variable.
# Globals:
# PASSPHRASE
# Arguments:
# None
#######################################
secure_unset_pass() { unset PASSPHRASE; PASSPHRASE=""; return 0; }
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f secure_unset_pass
#######################################
# Trap function to be called on 'ERR'.
# Arguments:
# 1: ${?}
# 2: ${BASH_SOURCE[0]}
# 3: ${LINENO}
# 4: ${FUNCNAME[0]:-main}
# 5: ${BASH_COMMAND}
#######################################
trap_on_err() {
declare -r errcode="$1"
declare -r errscrt="$2"
declare -r errline="$3"
declare -r errfunc="$4"
declare -r errcmmd="$5"
declare -g ERRTRAP='true'
trap - ERR INT TERM
stty echo 2>/dev/null || true
print_scr_err "${errcode}" "${errscrt}" "${errline}" "${errfunc}" "${errcmmd}"
power_off 16
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f trap_on_err
#######################################
# Security Trap on 'EXIT'.
# Globals:
# ERRTRAP
# Arguments:
# None
#######################################
trap_on_exit() {
trap - ERR EXIT INT TERM
[[ "${ERRTRAP,,}" == "false" ]] && print_scr_scc
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f trap_on_exit
#######################################
# Security Trap on 'INT' and 'TERM' to provide a deterministic way to not circumvent the nuke routine.
# Globals:
# NL
# RED
# Arguments:
# None
#######################################
trap_on_term() {
trap - ERR INT TERM
stty echo 2>/dev/null || true
printf "%b" "${NL}"
color_echo "${RED}" "✘ Received termination signal. System Power Off in 3 seconds."
power_off 3
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f trap_on_term
#######################################
# Check the integrity and authenticity of this script itself.
# Globals:
# GRE
# MAG
# RED
# Arguments:
# 0: Script Name
#######################################
verify_script() {
declare dir
# shellcheck disable=SC2312
dir="$(dirname "$(readlink -f "${0}")")"
declare script; script="$(basename "${0}")"
declare -a algo=( "sha512" )
declare cmd="" computed="" expected="" hashfile="" item="" sigfile=""
for item in "${algo[@]}"; do
hashfile="${dir}/${script}.${item}sum.txt"
sigfile="${hashfile}.sig"
cmd="${item}sum"
color_echo "${MAG}" "🔏 Verifying signature of: [${hashfile}]"
if ! gpgv --keyring "/etc/ciss/keys/${CDLB_DB_EXP_FPR}.gpg" "${sigfile}" "${hashfile}"; then
color_echo "${RED}" "✘ Signature verification failed for: [${hashfile}]"
color_echo "${RED}" "✘ System Power Off in 3 seconds."
power_off 3
else
color_echo "${GRE}" "🔏 Verifying signature of: [${hashfile}] successful."
fi
color_echo "${MAG}" "🔢 Recomputing Hash: [${item}]"
declare _=""
# shellcheck disable=SC2312
read -r computed _ < <("${cmd}" "${dir}/${script}")
read -r expected _ < "${hashfile}"
if [[ "${computed}" != "${expected}" ]]; then
color_echo "${RED}" "✘ Recomputed hash mismatch for : [${item}]"
color_echo "${RED}" "✘ System Power Off in 3 seconds."
power_off 3
fi
color_echo "${GRE}" "🔢 Recomputing Hash: [${item}] successful."
done
color_echo "${GRE}" "🔏 All signatures and hashes verified successfully. Proceeding."
return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f verify_script
#######################################
# Main Program Sequence.
# Globals:
# CURRENTDATE
# DEVICES_LUKS
# GRE
# MAG
# NL
# PASSPHRASE
# RED
# Arguments:
# None
#######################################
main() {
declare PASS="" COUNTER=0 PASS_SENT=0 WAIT_LOOP=0
exec 1>&2
trap 'trap_on_err "$?" "${BASH_SOURCE[0]}" "${LINENO}" "${FUNCNAME[0]:-main}" "${BASH_COMMAND}"' ERR
trap 'trap_on_exit' EXIT
trap 'trap_on_term' INT TERM
uname -a
printf "%b" "${NL}"
color_echo "${RED}" "Coresecret Connection established."
color_echo "${RED}" "Starting Time: ${CURRENTDATE}"
printf "%b" "${NL}"
color_echo "${MAG}" "Integrity self-check ..."
verify_script
while :; do
if [[ -b "${CDLB_MAPPER_DEV}" ]]; then
secure_unset_pass
printf "%b" "${NL}"
color_echo "${GRE}" "CISS LUKS Container successfully opened. Closing dropbear connection in 3 seconds."
sleep 3
exit 0
fi
if [[ "${COUNTER}" -ge 3 && "${PASS_SENT}" -eq 0 ]]; then
secure_unset_pass
break
fi
if [[ "${PASS_SENT}" -eq 0 ]]; then
COUNTER=$((COUNTER + 1))
# shellcheck disable=SC2310
read_passphrase || continue
printf '%s\n' "${PASSPHRASE}" >| /lib/cryptsetup/passfifo 2>/dev/null || :
PASS_SENT=1
WAIT_LOOP=0
else
WAIT_LOOP=$((WAIT_LOOP + 1))
COUNTER=$((COUNTER + 1))
if [[ "${WAIT_LOOP}" -ge 160 ]]; then
color_echo "${GRE}" "Please try again"
PASS_SENT=0
WAIT_LOOP=0
fi
fi
sleep 0.1
done
printf "%b" "${NL}"
color_echo "${GRE}" "No LUKS operations successful. Dropping to bash ..."
drop_bash
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f main
main "${@}"
# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh