dracut + systemd + LUKS + usbflash = auto unlock

Narratio olim incepit, cum Centos 7 (RHEL 7) dimissus est. Si encryption in activis cum Cento 6, nullae erant difficultates activitates reserationis activitatis cum USB mico clavium necessariis clavibus connexis. Sed cum 7 dimissus es, repente omnia non operata ut fuistis. Tunc solutionem invenire potuit in regressu dracut ad sysvinum utens simplici linea in config: echo 'omit_dracutmodules+="systemd"'> /etc/dracut.conf.d/luks-workaround.conf.
Quae statim nos privavit omni suavitate systemd - celeritatis et parallelae servitutis systematis, quod signanter ratio temporis startup reduxit.
Res adhuc ibi sunt; 905683
Sine exspectatione solutionis, illam mihi feci, et nunc cum publico, qui intersunt, legi.
dracut + systemd + LUKS + usbflash = auto unlock

introduction

Systemd, cum primum opus cum Cento 7, motus non causat, cum praeter minorem mutationem syntaxin administrandi, multum differentiae in principio non sentiebam. Postmodum probavi systemd, sed prima impressio parum vastata erat, quia tincidunt dracut non multum temporis vacavit ad sustentationem processus tabernus systematis utendi in conjunctione cum encryptione orbis. In genere laboravit, sed in tesseram orbis intrantes omni tempore servo incipit non est res maxime interesting.
Conatus fasciculum commendationum et manualium studui, intellexi in modo systematis conformationis cum USB fieri posse, sed solum cum connexione manuali cuiusque orbis cum clave in orbe USB, et ipsum orbem USB solum cum suo coniungi posse. UUID, LABEL non laboravit. Non satis commodum erat domi conservare, ut tandem in exspectando descendi et, VII fere annis expectato, neminem intellexi solvere problema.

problems

Scilicet, fere quisque potest scribere suum plugin pro dracut, sed opus non est tam facile. Contigit quod propter parallelam institutionis systematis naturam, non tam facile est codicem tuum comprehendere ac progressum oneratum mutare. Documenta dracut omnia non explicavit. Tamen post multa experimenta potui solvere problema.

Quomodo facitur

Innititur tribus unitatibus:

  1. luks-auto-key.service - perquirit agitet clavibus pro LUKS
  2. luks-auto.target - fungitur dependentia pro constructum-in systemd-cryptsetup unitates
  3. luks-auto-clean.service - purgat tempus lima creata a luks-auto-key.service

Et luks-auto-generator.sh scriptum est quod per systema educitur et unitates in parametris nucleis gignit. Similia generantia per unitates fstab creantur, etc.

luks-auto-generator.sh

Usura gutta-in.conf, mores normae systemd-cryptsetup mutatur addito luks-auto.target ad dependentiam suam.

luks-auto-key.service and luks-auto-key.sh

Haec unitas decurrit scripturam luks-auto-key.sh, quae, clavibus rd.luks innixa, media cum clavibus invenit et eas imitatur ad directorium temporale ad ulteriorem usum. Expleto processu, claves ex directorio temporali per luks-auto-clean deleverunt.

Fontes:

/usr/lib/dracut/modules.d/99luks-auto/module-setup.sh

#!/bin/bash

check () {
        if ! dracut_module_included "systemd"; then
                "luks-auto needs systemd in the initramfs"
                return 1
        fi
        return 255
}

depends () {
        echo "systemd"
        return 0
}

install () {
        inst "$systemdutildir/systemd-cryptsetup"
		inst_script "$moddir/luks-auto-generator.sh" "$systemdutildir/system-generators/luks-auto-generator.sh"
		inst_script "$moddir/luks-auto-key.sh" "/etc/systemd/system/luks-auto-key.sh"
		inst_script "$moddir/luks-auto.sh" "/etc/systemd/system/luks-auto.sh"
		inst "$moddir/luks-auto.target" "${systemdsystemunitdir}/luks-auto.target"
		inst "$moddir/luks-auto-key.service" "${systemdsystemunitdir}/luks-auto-key.service"
		inst "$moddir/luks-auto-clean.service" "${systemdsystemunitdir}/luks-auto-clean.service"
		ln_r "${systemdsystemunitdir}/luks-auto.target" "${systemdsystemunitdir}/initrd.target.wants/luks-auto.target"
		ln_r "${systemdsystemunitdir}/luks-auto-key.service" "${systemdsystemunitdir}/initrd.target.wants/luks-auto-key.service"
		ln_r "${systemdsystemunitdir}/luks-auto-clean.service" "${systemdsystemunitdir}/initrd.target.wants/luks-auto-clean.service"
}

/usr/lib/dracut/modules.d/99luks-auto/luks-auto-generator.sh


#!/bin/sh
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh

. /lib/dracut-lib.sh

SYSTEMD_RUN='/run/systemd/system'
CRYPTSETUP='/usr/lib/systemd/systemd-cryptsetup'
TOUT=$(getargs rd.luks.key.tout)
if [ ! -z "$TOUT" ]; then
	mkdir -p "${SYSTEMD_RUN}/luks-auto-key.service.d"
	cat > "${SYSTEMD_RUN}/luks-auto-key.service.d/drop-in.conf"  <<EOF
[Service]
Type=oneshot
ExecStartPre=/usr/bin/sleep $TOUT

EOF
fi
mkdir -p "$SYSTEMD_RUN/luks-auto.target.wants"
for argv in $(getargs rd.luks.uuid -d rd_LUKS_UUID); do
	_UUID=${argv#luks-}
	_UUID_ESC=$(systemd-escape -p $_UUID)
	mkdir -p "${SYSTEMD_RUN}/systemd-cryptsetup@luksx2d${_UUID_ESC}.service.d"
	cat > "${SYSTEMD_RUN}/systemd-cryptsetup@luksx2d${_UUID_ESC}.service.d/drop-in.conf"  <<EOF
[Unit]
After=luks-auto.target
ConditionPathExists=!/dev/mapper/luks-${_UUID}

EOF
	cat > "${SYSTEMD_RUN}/luks-auto@${_UUID_ESC}.service"  <<EOF
[Unit]
Description=luks-auto Cryptography Setup for %I
DefaultDependencies=no
Conflicts=umount.target
IgnoreOnIsolate=true
Before=luks-auto.target
BindsTo=dev-disk-byx2duuid-${_UUID_ESC}.device
After=dev-disk-byx2duuid-${_UUID_ESC}.device luks-auto-key.service
Before=umount.target

[Service]
Type=oneshot
RemainAfterExit=yes
TimeoutSec=0
ExecStart=/etc/systemd/system/luks-auto.sh ${_UUID}
ExecStop=$CRYPTSETUP detach 'luks-${_UUID}'
Environment=DRACUT_SYSTEMD=1
StandardInput=null
StandardOutput=syslog
StandardError=syslog+console

EOF
ln -fs ${SYSTEMD_RUN}/luks-auto@${_UUID_ESC}.service $SYSTEMD_RUN/luks-auto.target.wants/luks-auto@${_UUID_ESC}.service
done

/usr/lib/dracut/modules.d/99luks-auto/luks-auto-key.service


[Unit]
Description=LUKS AUTO key searcher
After=cryptsetup-pre.target
Before=luks-auto.target
DefaultDependencies=no

[Service]
Environment=DRACUT_SYSTEMD=1
Type=oneshot
ExecStartPre=/usr/bin/sleep 1
ExecStart=/etc/systemd/system/luks-auto-key.sh
RemainAfterExit=true
StandardInput=null
StandardOutput=syslog
StandardError=syslog+console

/usr/lib/dracut/modules.d/99luks-auto/luks-auto-key.sh


#!/bin/sh
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh
export DRACUT_SYSTEMD=1

. /lib/dracut-lib.sh
MNT_B="/tmp/luks-auto"
ARG=$(getargs rd.luks.key)
IFS=$':' _t=(${ARG})
KEY=${_t[0]}
F_FIELD=''
F_VALUE=''
if [ ! -z $KEY ] && [ ! -z ${_t[1]} ];then
	IFS=$'=' _t=(${_t[1]})
	F_FIELD=${_t[0]}
	F_VALUE=${_t[1]}
	F_VALUE="${F_VALUE%"}"
	F_VALUE="${F_VALUE#"}"
fi
mkdir -p $MNT_B

finding_luks_keys(){
	local _DEVNAME=''
	local _UUID=''
	local _TYPE=''
	local _LABEL=''
	local _MNT=''
	local _KEY="$1"
	local _F_FIELD="$2"
	local _F_VALUE="$3"
	local _RET=0	
	blkid -s TYPE -s UUID -s LABEL -u filesystem | grep -v -E -e "TYPE=".*_member"" -e "TYPE="crypto_.*"" -e "TYPE="swap"" | while IFS=$'' read -r _line; do
		IFS=$':' _t=($_line);
		_DEVNAME=${_t[0]}
		_UUID=''
		_TYPE=''
		_LABEL=''
		_MNT=''
		IFS=$' ' _t=(${_t[1]});
		for _a in "${_t[@]}"; do
			IFS=$'=' _v=(${_a});
			temp="${_v[1]%"}"
			temp="${temp#"}"
			case ${_v[0]} in
				'UUID')
					_UUID=$temp
				;;
				'TYPE')
					_TYPE=$temp
				;;
				'LABEL')
					_LABEL=$temp
				;;
			esac
		done
		if [ ! -z "$_F_FIELD" ];then
			case $_F_FIELD in
				'UUID')
					[ ! -z "$_F_VALUE" ] && [ "$_UUID" != "$_F_VALUE" ] && continue
				;;
				'LABEL')
					[ ! -z "$_F_VALUE" ] && [ "$_LABEL" != "$_F_VALUE" ] && continue
				;;
				*)
					[ "$_DEVNAME" != "$_F_FIELD" ] && continue
				;;
			esac
		fi
		_MNT=$(findmnt -n -o TARGET $_DEVNAME)
		if [ -z "$_MNT" ]; then
			_MNT=${MNT_B}/KEY-${_UUID}
			mkdir -p "$_MNT" && mount -o ro "$_DEVNAME" "$_MNT"
			_RET=$?
		else
			_RET=0
		fi
		if [ "${_RET}" -eq 0 ] && [ -f "${_MNT}/${_KEY}" ]; then
			cp "${_MNT}/${_KEY}" "$MNT_B/${_UUID}.key"
			info "Found ${_MNT}/${_KEY} on ${_UUID}"
		fi
		if [[ "${_MNT}" =~ "${MNT_B}" ]]; then
			umount "$_MNT" && rm -rfd --one-file-system "$_MNT"						
		fi
	done
	return 0
}
finding_luks_keys $KEY $F_FIELD $F_VALUE

/usr/lib/dracut/modules.d/99luks-auto/luks-auto.target


[Unit]
Description=LUKS AUTO target
After=systemd-readahead-collect.service systemd-readahead-replay.service
After=cryptsetup-pre.target luks-auto-key.service
Before=cryptsetup.target

/usr/lib/dracut/modules.d/99luks-auto/luks-auto.sh


#!/bin/sh
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh
export DRACUT_SYSTEMD=1
. /lib/dracut-lib.sh

MNT_B="/tmp/luks-auto"
CRYPTSETUP='/usr/lib/systemd/systemd-cryptsetup'

for i in $(ls -p $MNT_B | grep -v /);do
	info "Trying $i on $1..."
	$CRYPTSETUP attach "luks-$1" "/dev/disk/by-uuid/$1" $MNT_B/$i 'tries=1'
	if [ "$?" -eq "0" ]; then
		info "Found $i for $1"
		exit 0
	fi
done
warn "No key found for $1.  Fallback to passphrase mode."

/usr/lib/dracut/modules.d/99luks-auto/luks-auto-clean.service

[Unit]
Description=LUKS AUTO key cleaner
After=cryptsetup.target
DefaultDependencies=no

[Service]
Type=oneshot
ExecStart=/usr/bin/rm -rfd --one-file-system /tmp/luks-auto

/etc/dracut.conf.d/luks-auto.conf

add_dracutmodules+=" luks-auto "

occasum


mkdir -p /usr/lib/dracut/modules.d/99luks-auto/
# Ρ€Π°Π·ΠΌΠ΅Ρ‰Π°Π΅ΠΌ Ρ‚ΡƒΡ‚ ΠΏΠΎΡ‡Ρ‚ΠΈ всС Ρ„Π°ΠΉΠ»Ρ‹
chmod +x /usr/lib/dracut/modules.d/99luks-auto/*.sh
# создаСм Ρ„Π°ΠΉΠ» /etc/dracut.conf.d/luks-auto.conf
# И Π³Π΅Π½Π΅Ρ€ΠΈΡ€ΡƒΠ΅ΠΌ Π½ΠΎΠ²Ρ‹ΠΉ initramfs
dracut -f

conclusio,

Pro commodo, congruentiam cum nucleo mandatorum rectarum optionum servavi, sicut ad modum sysvini, quo facilius in vetustioribus institutionibus utendum est.

Source: www.habr.com