sys-fs/cryptsetup: add support for using detached LUKS headers

Closes: https://bugs.gentoo.org/831806
Closes: https://github.com/gentoo/gentoo/pull/23908
Signed-off-by: Martin Kjær Jørgensen <mkj@gotu.dk>
Signed-off-by: Mike Gilbert <floppym@gentoo.org>

3 files changed, 623 insertions, 0 deletions

diff --git a/sys-fs/cryptsetup/cryptsetup-2.4.3-r1.ebuild b/sys-fs/cryptsetup/cryptsetup-2.4.3-r1.ebuild
new file mode 100644
index 000000000000..3337dfaa89a0
--- /dev/null
+++ b/sys-fs/cryptsetup/cryptsetup-2.4.3-r1.ebuild
@@ -0,0 +1,136 @@
+# Copyright 1999-2022 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+inherit linux-info tmpfiles
+
+DESCRIPTION="Tool to setup encrypted devices with dm-crypt"
+HOMEPAGE="https://gitlab.com/cryptsetup/cryptsetup/blob/master/README.md"
+SRC_URI="https://www.kernel.org/pub/linux/utils/${PN}/v$(ver_cut 1-2)/${P/_/-}.tar.xz"
+
+LICENSE="GPL-2+"
+SLOT="0/12" # libcryptsetup.so version
+[[ ${PV} != *_rc* ]] && \
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86"
+CRYPTO_BACKENDS="gcrypt kernel nettle +openssl"
+# we don't support nss since it doesn't allow cryptsetup to be built statically
+# and it's missing ripemd160 support so it can't provide full backward compatibility
+IUSE="${CRYPTO_BACKENDS} +argon2 nls pwquality reencrypt ssh static static-libs test +udev urandom"
+RESTRICT="!test? ( test )"
+REQUIRED_USE="^^ ( ${CRYPTO_BACKENDS//+/} )
+	static? ( !gcrypt !udev )" #496612
+
+LIB_DEPEND="
+	dev-libs/json-c:=[static-libs(+)]
+	dev-libs/popt[static-libs(+)]
+	>=sys-apps/util-linux-2.31-r1[static-libs(+)]
+	argon2? ( app-crypt/argon2:=[static-libs(+)] )
+	gcrypt? (
+		dev-libs/libgcrypt:0=[static-libs(+)]
+		dev-libs/libgpg-error[static-libs(+)]
+	)
+	nettle? ( >=dev-libs/nettle-2.4[static-libs(+)] )
+	openssl? ( dev-libs/openssl:0=[static-libs(+)] )
+	pwquality? ( dev-libs/libpwquality[static-libs(+)] )
+	ssh? ( net-libs/libssh[static-libs(+)] )
+	sys-fs/lvm2[static-libs(+)]"
+# We have to always depend on ${LIB_DEPEND} rather than put behind
+# !static? () because we provide a shared library which links against
+# these other packages. #414665
+RDEPEND="static-libs? ( ${LIB_DEPEND} )
+	${LIB_DEPEND//\[static-libs\([+-]\)\]}
+	udev? ( virtual/libudev:= )"
+# vim-core needed for xxd in tests
+DEPEND="${RDEPEND}
+	static? ( ${LIB_DEPEND} )
+	test? ( app-editors/vim-core )"
+BDEPEND="
+	virtual/pkgconfig
+"
+
+S="${WORKDIR}/${P/_/-}"
+
+pkg_setup() {
+	local CONFIG_CHECK="~DM_CRYPT ~CRYPTO ~CRYPTO_CBC ~CRYPTO_SHA256"
+	local WARNING_DM_CRYPT="CONFIG_DM_CRYPT:\tis not set (required for cryptsetup)\n"
+	local WARNING_CRYPTO_SHA256="CONFIG_CRYPTO_SHA256:\tis not set (required for cryptsetup)\n"
+	local WARNING_CRYPTO_CBC="CONFIG_CRYPTO_CBC:\tis not set (required for kernel 2.6.19)\n"
+	local WARNING_CRYPTO="CONFIG_CRYPTO:\tis not set (required for cryptsetup)\n"
+	check_extra_config
+}
+
+src_prepare() {
+	sed -i '/^LOOPDEV=/s:$: || exit 0:' tests/{compat,mode}-test || die
+	default
+}
+
+src_configure() {
+	if use kernel ; then
+		ewarn "Note that kernel backend is very slow for this type of operation"
+		ewarn "and is provided mainly for embedded systems wanting to avoid"
+		ewarn "userspace crypto libraries."
+	fi
+
+	local myeconfargs=(
+		--disable-internal-argon2
+		--enable-shared
+		--sbindir=/sbin
+		# for later use
+		--with-default-luks-format=LUKS2
+		--with-tmpfilesdir="${EPREFIX}/usr/lib/tmpfiles.d"
+		--with-crypto_backend=$(for x in ${CRYPTO_BACKENDS//+/} ; do usev ${x} ; done)
+		$(use_enable argon2 libargon2)
+		$(use_enable nls)
+		$(use_enable pwquality)
+		$(use_enable reencrypt cryptsetup-reencrypt)
+		$(use_enable !static external-tokens)
+		$(use_enable static static-cryptsetup)
+		$(use_enable static-libs static)
+		$(use_enable udev)
+		$(use_enable !urandom dev-random)
+		$(use_enable ssh ssh-token)
+		$(usex argon2 '' '--with-luks2-pbkdf=pbkdf2')
+	)
+	econf "${myeconfargs[@]}"
+}
+
+src_test() {
+	if [[ ! -e /dev/mapper/control ]] ; then
+		ewarn "No /dev/mapper/control found -- skipping tests"
+		return 0
+	fi
+
+	local p
+	for p in /dev/mapper /dev/loop* ; do
+		addwrite ${p}
+	done
+
+	default
+}
+
+src_install() {
+	default
+
+	if use static ; then
+		mv "${ED}"/sbin/cryptsetup{.static,} || die
+		mv "${ED}"/sbin/veritysetup{.static,} || die
+		mv "${ED}"/sbin/integritysetup{.static,} || die
+		if use ssh ; then
+			mv "${ED}"/sbin/cryptsetup-ssh{.static,} || die
+		fi
+		if use reencrypt ; then
+			mv "${ED}"/sbin/cryptsetup-reencrypt{.static,} || die
+		fi
+	fi
+	find "${ED}" -type f -name "*.la" -delete || die
+
+	dodoc docs/v*ReleaseNotes
+
+	newconfd "${FILESDIR}"/2.4.3-dmcrypt.confd dmcrypt
+	newinitd "${FILESDIR}"/2.4.3-dmcrypt.rc dmcrypt
+}
+
+pkg_postinst() {
+	tmpfiles_process cryptsetup.conf
+}
diff --git a/sys-fs/cryptsetup/files/2.4.3-dmcrypt.confd b/sys-fs/cryptsetup/files/2.4.3-dmcrypt.confd
new file mode 100644
index 000000000000..8250e8268ac9
--- /dev/null
+++ b/sys-fs/cryptsetup/files/2.4.3-dmcrypt.confd
@@ -0,0 +1,120 @@
+# /etc/conf.d/dmcrypt
+
+# For people who run dmcrypt on top of some other layer (like raid),
+# use rc_need to specify that requirement.  See the runscript(8) man
+# page for more information.
+
+#--------------------
+# Instructions
+#--------------------
+
+# Note regarding the syntax of this file.  This file is *almost* bash,
+# but each line is evaluated separately.  Separate swaps/targets can be
+# specified.  The init-script which reads this file assumes that a
+# swap= or target= line starts a new section, similar to lilo or grub
+# configuration.
+
+# Note when using gpg keys and /usr on a separate partition, you will
+# have to copy /usr/bin/gpg to /bin/gpg so that it will work properly
+# and ensure that gpg has been compiled statically.
+# See http://bugs.gentoo.org/90482 for more information.
+
+# Note that the init-script which reads this file detects whether your
+# partition is LUKS or not. No mkfs is run unless you specify a makefs
+# option.
+
+# Global options:
+#----------------
+
+# How long to wait for each timeout (in seconds).
+dmcrypt_key_timeout=1
+
+# Max number of checks to perform (see dmcrypt_key_timeout).
+#dmcrypt_max_timeout=300
+
+# Number of password retries.
+dmcrypt_retries=5
+
+# Arguments:
+#-----------
+# target=<name>                      == Mapping name for partition.
+# swap=<name>                        == Mapping name for swap partition.
+# source='<dev>'                     == Real device for partition.
+#                                    Note: You can (and should) specify a tag like UUID
+#                                    for blkid (see -t option).  This is safer than using
+#                                    the full path to the device.
+# key='</path/to/keyfile>[:<mode>]'  == Fullpath from / or from inside removable media.
+# header='</path/to/header>'         == Full path to detached LUKS header file.
+# remdev='<dev>'                     == Device that will be assigned to removable media.
+# gpg_options='<opts>'               == Default are --quiet --decrypt
+# options='<opts>'                   == cryptsetup, for LUKS you can only use --readonly
+# loop_file='<file>'                 == Loopback file.
+#                                    Note: If you omit $source, then a free loopback will
+#                                    be looked up automatically.
+# pre_mount='cmds'                   == commands to execute before mounting partition.
+# post_mount='cmds'                  == commands to execute after mounting partition.
+# wait=5                             == wait given amount of seconds for source or
+#                                       detached header file appear.
+#-----------
+# Supported Modes
+# gpg					== decrypt and pipe key into cryptsetup.
+#						Note: new-line character must not be part of key.
+#						Command to erase \n char: 'cat key | tr -d '\n' > cleanKey'
+
+#--------------------
+# dm-crypt examples
+#--------------------
+
+## swap
+# Swap partitions. These should come first so that no keys make their
+# way into unencrypted swap.
+# If no options are given, they will default to: -c aes -h sha1 -d /dev/urandom
+# If no makefs is given then mkswap will be assumed
+#swap=crypt-swap
+#source='/dev/hda2'
+
+## /home with passphrase
+#target=crypt-home
+#source='/dev/hda5'
+
+## /home with regular keyfile
+#target=crypt-home
+#source='/dev/hda5'
+#key='/full/path/to/homekey'
+
+## /home with regular keyfile and detached header
+#target=crypt-home
+#source='/dev/hda5'
+#key='/full/path/to/homekey'
+#header='/full/path/to/header/file'
+
+## /home with gpg protected key
+#target=crypt-home
+#source='/dev/hda5'
+#key='/full/path/to/homekey:gpg'
+
+## /home with regular keyfile on removable media(such as usb-stick)
+#target=crypt-home
+#source='/dev/hda5'
+#key='/full/path/to/homekey'
+#remdev='/dev/sda1'
+
+## /home with gpg protected key on removable media(such as usb-stick)
+#target=crypt-home
+#source='/dev/hda5'
+#key='/full/path/to/homekey:gpg'
+#remdev='/dev/sda1'
+
+## /tmp with regular keyfile
+#target=crypt-tmp
+#source='/dev/hda6'
+#key='/full/path/to/tmpkey'
+#pre_mount='/sbin/mkreiserfs -f -f ${dev}'
+#post_mount='chown root:root ${mount_point}; chmod 1777 ${mount_point}'
+
+## Loopback file example
+#target='crypt-loop-home'
+#source='/dev/loop0'
+#loop_file='/mnt/crypt/home'
+
+# The file must be terminated by a newline.  Or leave this comment last.
diff --git a/sys-fs/cryptsetup/files/2.4.3-dmcrypt.rc b/sys-fs/cryptsetup/files/2.4.3-dmcrypt.rc
new file mode 100644
index 000000000000..0903ac5eabd0
--- /dev/null
+++ b/sys-fs/cryptsetup/files/2.4.3-dmcrypt.rc
@@ -0,0 +1,367 @@
+#!/sbin/openrc-run
+# Copyright 1999-2015 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+depend() {
+	use modules
+	before checkfs fsck
+
+	if grep -qs ^swap= "${conf_file}" ; then
+		before swap
+	fi
+}
+
+# We support multiple dmcrypt instances based on $SVCNAME
+conf_file="/etc/conf.d/${SVCNAME}"
+
+# Get splash helpers if available.
+if [ -e /sbin/splash-functions.sh ] ; then
+	. /sbin/splash-functions.sh
+fi
+
+# Setup mappings for an individual target/swap
+# Note: This relies on variables localized in the main body below.
+dm_crypt_execute() {
+	local dev ret mode foo source_dev
+
+	if [ -z "${target}" -a -z "${swap}" ] ; then
+		return
+	fi
+
+	# Set up default values.
+	: ${dmcrypt_key_timeout:=1}
+	: ${dmcrypt_max_timeout:=300}
+	: ${dmcrypt_retries:=5}
+	: ${wait:=5}
+
+	# Handle automatic look up of the source path.
+	if [ -z "${source}" -a -n "${loop_file}" ] ; then
+		source=$(losetup --show -f "${loop_file}")
+	fi
+	case ${source} in
+	*=*)
+		i=0
+		while [ ${i} -lt ${wait} ]; do
+			if source_dev="$(blkid -l -t "${source}" -o device)"; then
+				source="${source_dev}"
+				break
+			fi
+			: $((i += 1))
+			einfo "waiting for source \"${source}\" for ${target}..."
+			sleep 1
+		done
+		;;
+	esac
+	if [ -z "${source}" ] || [ ! -e "${source}" ] ; then
+		ewarn "source \"${source}\" for ${target} missing, skipping..."
+		return
+	fi
+
+	if [ -n "${header}" ] ; then
+		header_opt="--header=${header}"
+
+		i=0
+		while [ ! -e "${header}" ] && [ ${i} -lt ${wait} ] ; do
+			: $((i += 1))
+			einfo "Waiting for header ${header} to appear for ${target} ${i}/${dmcrypt_max_timeout} ..."
+			sleep 1
+		done
+		if [ ${i} -gt ${wait} ] || [ ${i} -eq ${wait} ] ; then
+			ewarn "Waited ${i} times for header file ${header}. Aborting ${target}."
+			return
+		fi
+	else
+		header_opt=""
+	fi
+
+	if [ -n "${target}" ] ; then
+		# let user set options, otherwise leave empty
+		: ${options:=' '}
+	elif [ -n "${swap}" ] ; then
+		if cryptsetup ${header_opt} isLuks ${source} 2>/dev/null ; then
+			ewarn "The swap you have defined is a LUKS partition. Aborting crypt-swap setup."
+			return
+		fi
+		target=${swap}
+		# swap contents do not need to be preserved between boots, luks not required.
+		# suspend2 users should have initramfs's init handling their swap partition either way.
+		: ${options:='-c aes -h sha1 -d /dev/urandom'}
+		: ${pre_mount:='mkswap ${dev}'}
+	fi
+
+	if [ -n "${loop_file}" ] ; then
+		dev="/dev/mapper/${target}"
+		ebegin "  Setting up loop device ${source}"
+		losetup ${source} ${loop_file}
+	fi
+
+	# cryptsetup:
+	# open   <device> <name>      # <device> is $source
+	# create <name>   <device>    # <name>   is $target
+	local arg1="create" arg2="${target}" arg3="${source}"
+	if cryptsetup ${header_opt} isLuks ${source} 2>/dev/null ; then
+		arg1="open"
+		arg2="${source}"
+		arg3="${target}"
+	fi
+
+	# Older versions reported:
+	#	${target} is active:
+	# Newer versions report:
+	#	${target} is active[ and is in use.]
+	if cryptsetup ${header_opt} status ${target} | egrep -q ' is active' ; then
+		einfo "dm-crypt mapping ${target} is already configured"
+		return
+	fi
+	splash svc_input_begin ${SVCNAME} >/dev/null 2>&1
+
+	# Handle keys
+	if [ -n "${key}" ] ; then
+		read_abort() {
+			# some colors
+			local ans savetty resettty
+			[ -z "${NORMAL}" ] && eval $(eval_ecolors)
+			einfon "  $1? (${WARN}yes${NORMAL}/${GOOD}No${NORMAL}) "
+			shift
+			# This is ugly as s**t.  But POSIX doesn't provide `read -t`, so
+			# we end up having to implement our own crap with stty/etc...
+			savetty=$(stty -g)
+			resettty='stty ${savetty}; trap - EXIT HUP INT TERM'
+			trap 'eval "${resettty}"' EXIT HUP INT TERM
+			stty -icanon
+			stty min 0 time "$(( $2 * 10 ))"
+			ans=$(dd count=1 bs=1 2>/dev/null) || ans=''
+			eval "${resettty}"
+			if [ -z "${ans}" ] ; then
+				printf '\r'
+			else
+				echo
+			fi
+			case ${ans} in
+				[yY]) return 0;;
+				*) return 1;;
+			esac
+		}
+
+		# Notes: sed not used to avoid case where /usr partition is encrypted.
+		mode=${key##*:} && ( [ "${mode}" = "${key}" ] || [ -z "${mode}" ] ) && mode=reg
+		key=${key%:*}
+		case "${mode}" in
+		gpg|reg)
+			# handle key on removable device
+			if [ -n "${remdev}" ] ; then
+				# temp directory to mount removable device
+				local mntrem="${RC_SVCDIR}/dm-crypt-remdev.$$"
+				if [ ! -d "${mntrem}" ] ; then
+					if ! mkdir -p "${mntrem}" ; then
+						ewarn "${source} will not be decrypted ..."
+						einfo "Reason: Unable to create temporary mount point '${mntrem}'"
+						return
+					fi
+				fi
+				i=0
+				einfo "Please insert removable device for ${target}"
+				while [ ${i} -lt ${dmcrypt_max_timeout} ] ; do
+					foo=""
+					if mount -n -o ro "${remdev}" "${mntrem}" 2>/dev/null >/dev/null ; then
+						# keyfile exists?
+						if [ ! -e "${mntrem}${key}" ] ; then
+							umount -n "${mntrem}"
+							rmdir "${mntrem}"
+							einfo "Cannot find ${key} on removable media."
+							read_abort "Abort" ${dmcrypt_key_timeout} && return
+						else
+							key="${mntrem}${key}"
+							break
+						fi
+					else
+						[ -e "${remdev}" ] \
+							&& foo="mount failed" \
+							|| foo="mount source not found"
+					fi
+					: $((i += 1))
+					read_abort "Stop waiting after $i attempts (${foo})" -t 1 && return
+				done
+			else    # keyfile ! on removable device
+				if [ ! -e "${key}" ] ; then
+					ewarn "${source} will not be decrypted ..."
+					einfo "Reason: keyfile ${key} does not exist."
+					return
+				fi
+			fi
+			;;
+		*)
+			ewarn "${source} will not be decrypted ..."
+			einfo "Reason: mode ${mode} is invalid."
+			return
+			;;
+		esac
+	else
+		mode=none
+	fi
+	ebegin "  ${target} using: ${header_opt} ${options} ${arg1} ${arg2} ${arg3}"
+	if [ "${mode}" = "gpg" ] ; then
+		: ${gpg_options:='-q -d'}
+		# gpg available ?
+		if command -v gpg >/dev/null ; then
+			i=0
+			while [ ${i} -lt ${dmcrypt_retries} ] ; do
+				# paranoid, don't store key in a variable, pipe it so it stays very little in ram unprotected.
+				# save stdin stdout stderr "values"
+				timeout ${dmcrypt_max_timeout} gpg ${gpg_options} ${key} 2>/dev/null | \
+					cryptsetup ${header_opt} --key-file - ${options} ${arg1} ${arg2} ${arg3}
+				ret=$?
+				# The timeout command exits 124 when it times out.
+				[ ${ret} -eq 0 -o ${ret} -eq 124 ] && break
+				: $(( i += 1 ))
+			done
+			eend ${ret} "failure running cryptsetup"
+		else
+			ewarn "${source} will not be decrypted ..."
+			einfo "Reason: cannot find gpg application."
+			einfo "You have to install app-crypt/gnupg first."
+			einfo "If you have /usr on its own partition, try copying gpg to /bin ."
+		fi
+	else
+		if [ "${mode}" = "reg" ] ; then
+			cryptsetup ${header_opt} ${options} -d ${key} ${arg1} ${arg2} ${arg3}
+			ret=$?
+			eend ${ret} "failure running cryptsetup"
+		else
+			cryptsetup ${header_opt} ${options} ${arg1} ${arg2} ${arg3}
+			ret=$?
+			eend ${ret} "failure running cryptsetup"
+		fi
+	fi
+	if [ -d "${mntrem}" ] ; then
+		umount -n ${mntrem} 2>/dev/null >/dev/null
+		rmdir ${mntrem} 2>/dev/null >/dev/null
+	fi
+	splash svc_input_end ${SVCNAME} >/dev/null 2>&1
+
+	if [ ${ret} -ne 0 ] ; then
+		cryptfs_status=1
+	else
+		if [ -n "${pre_mount}" ] ; then
+			dev="/dev/mapper/${target}"
+			eval ebegin \""    pre_mount: ${pre_mount}"\"
+			eval "${pre_mount}" > /dev/null
+			ewend $? || cryptfs_status=1
+		fi
+	fi
+}
+
+# Lookup optional bootparams
+get_bootparam_val() {
+	# We're given something like:
+	#    foo=bar=cow
+	# Return the "bar=cow" part.
+	case $1 in
+	*=*)
+		echo "${1#*=}"
+		;;
+	esac
+}
+
+start() {
+	local print_header=true cryptfs_status=0
+	local gpg_options key loop_file target targetline options pre_mount post_mount source swap remdev
+
+	local x
+	for x in $(cat /proc/cmdline) ; do
+		case "${x}" in
+		key_timeout=*)
+			dmcrypt_key_timeout=$(get_bootparam_val "${x}")
+			;;
+		esac
+	done
+
+	while read targetline <&3 ; do
+		case ${targetline} in
+		# skip comments and blank lines
+		""|"#"*) continue ;;
+		# skip service-specific openrc configs #377927
+		rc_*) continue ;;
+		esac
+
+		${print_header} && ebegin "Setting up dm-crypt mappings"
+		print_header=false
+
+		# check for the start of a new target/swap
+		case ${targetline} in
+		target=*|swap=*)
+			# If we have a target queued up, then execute it
+			dm_crypt_execute
+
+			# Prepare for the next target/swap by resetting variables
+			unset gpg_options key loop_file target options pre_mount post_mount source swap remdev wait header header_opt
+			;;
+
+		gpg_options=*|remdev=*|key=*|loop_file=*|options=*|pre_mount=*|post_mount=*|wait=*|source=*|header=*)
+			if [ -z "${target}${swap}" ] ; then
+				ewarn "Ignoring setting outside target/swap section: ${targetline}"
+				continue
+			fi
+			;;
+
+		dmcrypt_*=*)
+			# ignore global options
+			continue
+			;;
+
+		*)
+			ewarn "Skipping invalid line in ${conf_file}: ${targetline}"
+			;;
+		esac
+
+		# Queue this setting for the next call to dm_crypt_execute
+		eval "${targetline}"
+	done 3< ${conf_file}
+
+	# If we have a target queued up, then execute it
+	dm_crypt_execute
+
+	ewend ${cryptfs_status} "Failed to setup dm-crypt devices"
+}
+
+stop() {
+	local line print_header
+
+	# Break down all mappings
+	print_header=true
+	egrep "^(target|swap)=" ${conf_file} | \
+	while read line ; do
+		${print_header} && einfo "Removing dm-crypt mappings"
+		print_header=false
+
+		target= swap=
+		eval ${line}
+
+		[ -n "${swap}" ] && target=${swap}
+		if [ -z "${target}" ] ; then
+			ewarn "invalid line in ${conf_file}: ${line}"
+			continue
+		fi
+
+		ebegin "  ${target}"
+		cryptsetup ${header_opt} remove ${target}
+		eend $?
+	done
+
+	# Break down loop devices
+	print_header=true
+	grep '^source=./dev/loop' ${conf_file} | \
+	while read line ; do
+		${print_header} && einfo "Detaching dm-crypt loop devices"
+		print_header=false
+
+		source=
+		eval ${line}
+
+		ebegin "  ${source}"
+		losetup -d "${source}"
+		eend $?
+	done
+
+	return 0
+}