#!/bin/bash
#
# Dump certificates from the HAProxy stats or master socket to the filesystem
# Experimental script
#

set -e

export BASEPATH=${BASEPATH:-/etc/haproxy}/
export SOCKET=${SOCKET:-/var/run/haproxy-master.sock}
export DRY_RUN=0
export DEBUG=
export VERBOSE=
export M="@1 "
export TMP

vecho() {

	[ -n "$VERBOSE" ] && echo "$@"
	return 0
}

read_certificate() {
	name=$1
	crt_filename=
	key_filename=

	OFS=$IFS
	IFS=":"

	while read -r key value; do
		case "$key" in
			"Crt filename")
				crt_filename="${value# }"
				key_filename="${value# }"
			;;
			"Key filename")
				key_filename="${value# }"
			;;
		esac
	done < <(echo "${M}show ssl cert ${name}" | socat "${SOCKET}" -)
	IFS=$OFS

	if [ -z "$crt_filename" ] || [ -z "$key_filename" ]; then
		return 1
	fi

	# handle fields without a crt-base/key-base
	[ "${crt_filename:0:1}" != "/" ] && crt_filename="${BASEPATH}${crt_filename}"
	[ "${key_filename:0:1}" != "/" ] && key_filename="${BASEPATH}${key_filename}"

	vecho "name:$name"
	vecho "crt:$crt_filename"
	vecho "key:$key_filename"

	export NAME="$name"
	export CRT_FILENAME="$crt_filename"
	export KEY_FILENAME="$key_filename"

	return 0
}

cmp_certkey() {
	prev=$1
	new=$2

	if [ ! -f "$prev" ]; then
		return 1;
	fi

	if ! cmp -s <(openssl x509 -in "$prev" -noout -fingerprint -sha256) <(openssl x509 -in "$new" -noout -fingerprint -sha256); then
		return 1
	fi

	return 0
}

dump_certificate() {
	name=$1
	prev_crt=$2
	prev_key=$3
	r="tmp.${RANDOM}"
	d="old.$(date +%s)"
	new_crt="$TMP/$(basename "$prev_crt").${r}"
	new_key="$TMP/$(basename "$prev_key").${r}"

	if ! touch "${new_crt}" || ! touch "${new_key}"; then
		echo "[ALERT] ($$) : can't dump \"$name\", can't create tmp files" >&2
		return 1
	fi

	echo "${M}dump ssl cert ${name}" | socat "${SOCKET}" - | openssl pkey >> "${new_key}"
	# use crl2pkcs7 as a way to dump multiple x509, storeutl could be used in modern versions of openssl
	echo "${M}dump ssl cert ${name}" | socat "${SOCKET}" - | openssl crl2pkcs7 -nocrl -certfile /dev/stdin | openssl pkcs7 -print_certs  >> "${new_crt}"

	if ! cmp -s <(openssl x509 -in "${new_crt}" -pubkey -noout) <(openssl pkey -in "${new_key}" -pubout); then
		echo "[ALERT] ($$) : Private key \"${new_key}\"  and public key \"${new_crt}\" don't match" >&2
		return 1
	fi

	if cmp_certkey "${prev_crt}" "${new_crt}"; then
		echo "[NOTICE] ($$) : ${crt_filename} is already up to date" >&2
		return 0
	fi

	# move the current certificates to ".old.timestamp"
	if [ -f "${prev_crt}" ] && [ -f "${prev_key}" ]; then
		mv "${prev_crt}" "${prev_crt}.${d}"
		[ "${prev_crt}" != "${prev_key}" ] && mv "${prev_key}" "${prev_key}.${d}"
	fi

	# move the new certificates to old place
	mv "${new_crt}" "${prev_crt}"
	[ "${prev_crt}" != "${prev_key}" ] && mv "${new_key}" "${prev_key}"

	return 0
}

dump_all_certificates() {
	echo "${M}show ssl cert" | socat "${SOCKET}" - | grep -v '^#' | grep -v '^$' | while read -r line; do
		export NAME
		export CRT_FILENAME
		export KEY_FILENAME

		if read_certificate "$line"; then
			[ "${DRY_RUN}" = "0" ] && dump_certificate "$NAME" "$CRT_FILENAME" "$KEY_FILENAME"
		else
			echo "[WARNING] ($$) : can't dump \"$name\", crt/key filename details not found in \"show ssl cert\"" >&2
		fi

	done
}

usage() {
	echo "Usage:"
	echo " $0 [options]* [cert]*"
	echo ""
	echo " Dump certificates from the HAProxy stats or master socket to the filesystem"
	echo " Require socat and openssl"
	echo " EXPERIMENTAL script, backup your files!"
	echo " The script will move your previous files to FILE.old.unixtimestamp (ex: foo.com.pem.old.1759044998)"

	echo ""
	echo "Options:"
	echo "  -S, --master-socket <path>   Use the master socket at <path> (default: ${SOCKET})"
	echo "  -s, --socket <path>          Use the stats socket at <path>"
	echo "  -p, --path <path>            Specifiy a base path for relative files (default: ${BASEPATH})"
	echo "  -n, --dry-run                Read certificates on the socket but don't dump them"
	echo "  -d, --debug                  Debug mode, set -x"
	echo "  -v, --verbose                Verbose mode"
	echo "  -h, --help                   This help"
	echo "  --                           End of options"
	echo ""
	echo "Examples:"
	echo "  $0 -v -p ${BASEPATH} -S ${SOCKET}"
	echo "  $0 -v -p ${BASEPATH} -S ${SOCKET} bar.com.rsa.pem"
	echo "  $0 -v -p ${BASEPATH} -S ${SOCKET} -- foo.com.ecdsa.pem bar.com.rsa.pem"
}

main() {
	while [ -n "$1" ]; do
		case "$1" in
			-S|--master-socket)
				SOCKET="$2"
				M="@1 "
				shift 2
				;;
			-s|--socket)
				SOCKET="$2"
				M=
				shift 2
				;;
			-p|--path)
				BASEPATH="$2/"
				shift 2
				;;
			-n|--dry-run)
				DRY_RUN=1
				shift
				;;
			-d|--debug)
				DEBUG=1
				shift
				;;
			-v|--verbose)
				VERBOSE=1
				shift
				;;
			-h|--help)
				usage "$@"
				exit 0
				;;
			--)
				shift
				break
				;;
			-*)
				echo "[ALERT] ($$) : Unknown option '$1'" >&2
				usage "$@"
				exit 1
				;;
			*)
				break
				;;
		esac
	done

	if [ -n "$DEBUG" ]; then
		set -x
	fi

	TMP=${TMP:-$(mktemp -d)}

	if [ -z "$1" ]; then
		dump_all_certificates
	else
		# compute the certificates names at the end of the command
		while [ -n "$1" ]; do
			if ! read_certificate "$1"; then
				echo "[ALERT] ($$) : can't dump \"$1\", crt/key filename details not found in \"show ssl cert\"" >&2
				exit 1
			fi
			[ "${DRY_RUN}" = "0" ] && dump_certificate "$NAME" "$CRT_FILENAME" "$KEY_FILENAME"
			shift
		done
	fi
}

trap 'rm -rf -- "$TMP"' EXIT
main "$@"