From patchwork Fri Feb 17 13:05:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Quirin Gylstorff X-Patchwork-Id: 13144672 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0900C64ED8 for ; Fri, 17 Feb 2023 13:05:53 +0000 (UTC) Received: from mta-64-228.siemens.flowmailer.net (mta-64-228.siemens.flowmailer.net [185.136.64.228]) by mx.groups.io with SMTP id smtpd.web10.5861.1676639145667462777 for ; Fri, 17 Feb 2023 05:05:45 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=Quirin.Gylstorff@siemens.com header.s=fm1 header.b=VUm7du74; spf=pass (domain: rts-flowmailer.siemens.com, ip: 185.136.64.228, mailfrom: fm-51332-20230217130543402b2e6da89a37a7e1-nb__qz@rts-flowmailer.siemens.com) Received: by mta-64-228.siemens.flowmailer.net with ESMTPSA id 20230217130543402b2e6da89a37a7e1 for ; Fri, 17 Feb 2023 14:05:43 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=Quirin.Gylstorff@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:References:In-Reply-To; bh=kb2gzLqQ0Kdf8Ua9sTCDfII4OxScHnRG1IDzvyX0sGM=; b=VUm7du74Llz8sUY4nM0Wg6swgh9PSnd+VG1LWGPC/1B3Bj0LnHCNYPRfv/m6O7aNpoHwoi KcfxoVM0ZjCHdhGE11TR01V9ArcGAVapBuGTyV+k4xBitFAxUjK4Ij2+7rbWT6DaaK/ySfKl C5Ygx1VuI2V4/DbQX0n6h6vW3YeuQ=; From: Quirin Gylstorff To: cip-dev@lists.cip-project.org, christian.storm@siemens.com, jan.kiszka@siemens.com Subject: [cip-dev][isar-cip-core][RFC v2 4/7] Add initramfs hook to encrypt a partition Date: Fri, 17 Feb 2023 14:05:37 +0100 Message-Id: <20230217130540.509910-5-Quirin.Gylstorff@siemens.com> In-Reply-To: <20230217130540.509910-1-Quirin.Gylstorff@siemens.com> References: <20230217130540.509910-1-Quirin.Gylstorff@siemens.com> MIME-Version: 1.0 X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-51332:519-21489:flowmailer List-Id: X-Webhook-Received: from li982-79.members.linode.com [45.33.32.79] by aws-us-west-2-korg-lkml-1.web.codeaurora.org with HTTPS for ; Fri, 17 Feb 2023 13:05:53 -0000 X-Groupsio-URL: https://lists.cip-project.org/g/cip-dev/message/10716 From: Quirin Gylstorff This creates a new luks encrypted ext4 partition with a the key stored in the tpm2. The initial key is randomly generated and removed from the LUKS partition. Therefore a new key cannot be added by the user and if the LUKS header is corrupted the data is no longer readable. Signed-off-by: Quirin Gylstorff --- .../files/encrypt_partition.env.tmpl | 2 + .../files/encrypt_partition.hook | 49 +++++++ .../files/encrypt_partition.script | 135 ++++++++++++++++++ .../initramfs-crypt-hook_0.1.bb | 37 +++++ wic/x86-efibootguard.wks.in | 4 +- 5 files changed, 225 insertions(+), 2 deletions(-) create mode 100644 recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.env.tmpl create mode 100644 recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.hook create mode 100644 recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.script create mode 100644 recipes-initramfs/initramfs-crypt-hook/initramfs-crypt-hook_0.1.bb diff --git a/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.env.tmpl b/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.env.tmpl new file mode 100644 index 0000000..943fe4b --- /dev/null +++ b/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.env.tmpl @@ -0,0 +1,2 @@ +PARTITIONS="${CRYPT_PARTITIONS}" +REDUDUCE_DEVICE_SIZE="${CRYPT_REDUDUCE_DEVICE_SIZE}" diff --git a/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.hook b/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.hook new file mode 100644 index 0000000..96e084a --- /dev/null +++ b/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.hook @@ -0,0 +1,49 @@ +#!/bin/sh +# Copyright (C) Siemens AG, 2020-2022 +# +# SPDX-License-Identifier: MIT + +PREREQ="" + +prereqs() +{ + echo "$PREREQ" +} + +case $1 in +prereqs) + prereqs + exit 0 + ;; +esac + +. /usr/share/initramfs-tools/scripts/functions +. /usr/share/initramfs-tools/hook-functions + +manual_add_modules tpm +manual_add_modules tpm_tis_core +manual_add_modules tpm_tis +manual_add_modules tpm_crb +manual_add_modules dm_mod +manual_add_modules dm_crypt + +copy_exec /usr/bin/openssl +copy_exec /usr/sbin/mke2fs +copy_exec /usr/bin/grep +copy_exec /usr/bin/awk +copy_exec /usr/bin/expr +copy_exec /usr/sbin/e2fsck +copy_exec /usr/sbin/resize2fs +copy_exec /usr/sbin/cryptsetup +copy_exec /usr/bin/systemd-cryptenroll +copy_exec /usr/lib/systemd/systemd-cryptsetup + +if [ -x cryptsetup-reencrypt ]; then + copy_exec /usr/sbin/cryptsetup-reencrypt +fi + +for _LIBRARY in /usr/lib/*/libtss2*; do + copy_exec "$_LIBRARY" +done + +copy_file library /usr/share/encrypt_partition/encrypt_partition.env /usr/share/encrypt_partition/encrypt_partition.env diff --git a/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.script b/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.script new file mode 100644 index 0000000..e58794e --- /dev/null +++ b/recipes-initramfs/initramfs-crypt-hook/files/encrypt_partition.script @@ -0,0 +1,135 @@ +#!/bin/sh +# +# CIP Core, generic profile +# +# Copyright (c) Siemens AG, 2023 +# +# Authors: +# Quirin Gylstorff +# +# SPDX-License-Identifier: MIT +prereqs() +{ + # Make sure that this script is run last in local-top + local req + for req in "${0%/*}"/*; do + script="${req##*/}" + if [ "$script" != "${0##*/}" ]; then + printf '%s\n' "$script" + fi + done +} +case $1 in +prereqs) + prereqs + exit 0 + ;; +esac + +. /scripts/functions + +# get configuration variables +. /usr/share/encrypt_partition/encrypt_partition.env + +# load necessary kernel modules: +modprobe tpm_tis +modprobe tpm_crb + +# fixed tpm device or do we need to find it +tpm_device=/dev/tpmrm0 +partition_sets="$PARTITIONS" + +open_tpm2_partition() { + if ! /usr/lib/systemd/systemd-cryptsetup attach "$crypt_mount_name" \ + "$1" - tpm2-device="$tpm_device"; then + panic "Can't decrypt '$1' !" + fi +} + +enroll_tpm2_token() { + #check systemd version and export password if necessary + if [ -x /usr/bin/systemd-cryptenroll ]; then + systemd_version=$(systemd-cryptenroll --version | \ + awk -F " " 'NR==1{print $2 }') + #check systemd version and export password if necessary + if [ "$systemd_version" -ge "251" ]; then + PASSWORD=$(cat "$2" ) + export PASSWORD + /usr/bin/systemd-cryptenroll --tpm2-device="$tpm_device" \ + --tpm2-pcrs=7 "$1" + PASSWORD= + else + panic "Unknown systemd version: '$systemd_version'!" + fi + fi +} + +reencrypt_existing_partition() { + part_device=$(readlink -f "$partition") + part_size_blocks=$(cat /sys/class/block/"$(awk -v dev=$part_device 'BEGIN{split(dev,a,"/"); print a[3]}' )"/size) + reduced_size=$(expr $part_size_blocks - 65536 ) + reduced_size_in_byte=$(expr $reduced_size \* 512) + reduced_size_in_kb=$(expr $reduced_size_in_byte / 1024)K + resize2fs "$1" "$reduced_size_in_kb" + if [ -x cryptsetup-reencrypt ]; then + /usr/sbin/cryptsetup-reencrypt --new --reduce-device-size "${REDUDUCE_DEVICE_SIZE}" $1 < $2 + else + /usr/sbin/cryptsetup reencrypt --encrypt --reduce-device-size "${REDUDUCE_DEVICE_SIZE}" $1 < $2 + fi + +} + + +if [ ! -e "$tpm_device" ]; then + panic "tpm device '$tpm_device' does not exists - cannot create a encrypted device!" +fi + +for partition_set in $partition_sets; do + partition_label=$(awk -v var=$partition_set 'BEGIN{split(var,a,":"); print a[1]}') + partition_mountpoint=$(awk -v var=$partition_set 'BEGIN{split(var,a,":"); print a[2]}') + partition_format=$(awk -v var=$partition_set 'BEGIN{split(var,a,":"); print a[3]}') + partition=/dev/disk/by-partlabel/$partition_label + crypt_mount_name="encrypted_$partition_label" + decrypted_part=/dev/mapper/"$crypt_mount_name" + + # check if partition is already encrypted with systemd-tpm2 + if /usr/sbin/cryptsetup luksDump --batch-mode "$partition" \ + | grep -q "systemd-tpm2"; then + open_tpm2_partition "$partition" + if ! mount -t $(get_fstype "${decrypted_part}") "${decrypted_part}" "${rootmnt}${partition_mountpoint}"; then + panic "Can't mount encrypted partition '${decrypted_part}'!" + fi + continue + fi + + # create random password for initial encryption + # this will be dropped after reboot + tmp_key=/tmp/"$partition_label-lukskey" + openssl rand -base64 32 > "$tmp_key" + + case "${partition_format}" in + "reencrypt") + reencrypt_existing_partition "$partition" "$tmp_key" + enroll_tpm2_token "$partition" "$tmp_key" + open_tpm2_partition "$partition" + ;; + "format") + /usr/sbin/cryptsetup luksFormat --batch-mode \ + --type luks2 "$partition" < "$tmp_key" + enroll_tpm2_token "$partition" "$tmp_key" + open_tpm2_partition_tpm2_partition "$partition" + mke2fs -t ext4 "${decrypted_part}" + ;; + *) + panic "Unknown value ${partition_format}. Cannot create a encrypted partition !" + ;; + esac + + if ! mount -t $(get_fstype "${decrypted_part}") "${decrypted_part}" "${rootmnt}${partition_mountpoint}"; then + panic "Can't mount encrypted partition '${decrypted_part}'!" + fi + + # delete initial key + # afterwards no new keys can be enrolled + /usr/bin/systemd-cryptenroll "$partition" --wipe-slot=0 +done diff --git a/recipes-initramfs/initramfs-crypt-hook/initramfs-crypt-hook_0.1.bb b/recipes-initramfs/initramfs-crypt-hook/initramfs-crypt-hook_0.1.bb new file mode 100644 index 0000000..ba2b884 --- /dev/null +++ b/recipes-initramfs/initramfs-crypt-hook/initramfs-crypt-hook_0.1.bb @@ -0,0 +1,37 @@ +# +# CIP Core, generic profile +# +# Copyright (c) Siemens AG, 2020-2022 +# +# Authors: +# Quirin Gylstorff +# +# SPDX-License-Identifier: MIT + + +inherit dpkg-raw + +DEBIAN_DEPENDS = "initramfs-tools, cryptsetup, systemd(>= 251), \ + awk, openssl, libtss2-esys-3.0.2-0, libtss2-rc0, libtss2-mu0, e2fsprogs" + +SRC_URI += "file://encrypt_partition.hook \ + file://encrypt_partition.script \ + file://encrypt_partition.env.tmpl" + +CRYPT_PARTITIONS ??= "home:/home:reencrypt var:/var:reencrypt" +CRYPT_REDUDUCE_DEVICE_SIZE="32M" + +TEMPLATE_VARS = "CRYPT_PARTITIONS CRYPT_REDUDUCE_DEVICE_SIZE" +TEMPLATE_FILES = "encrypt_partition.env.tmpl" + +do_install[cleandirs] += " \ + ${D}/usr/share/initramfs-tools/hooks \ + ${D}/usr/share/encrypt_partition \ + ${D}/usr/share/initramfs-tools/scripts/local-bottom" +do_install() { + install -m 0600 "${WORKDIR}/encrypt_partition.env" "${D}/usr/share/encrypt_partition/encrypt_partition.env" + install -m 0755 "${WORKDIR}/encrypt_partition.script" \ + "${D}/usr/share/initramfs-tools/scripts/local-bottom/encrypt_partition" + install -m 0755 "${WORKDIR}/encrypt_partition.hook" \ + "${D}/usr/share/initramfs-tools/hooks/encrypt_partition" +} diff --git a/wic/x86-efibootguard.wks.in b/wic/x86-efibootguard.wks.in index b635a8b..1d29583 100644 --- a/wic/x86-efibootguard.wks.in +++ b/wic/x86-efibootguard.wks.in @@ -7,7 +7,7 @@ part --source rawcopy --sourceparams "file=${IMAGE_FULLNAME}.squashfs" --align 1 part --source empty --align 1024 --fixed-size 1G --uuid "${ABROOTFS_PART_UUID_B}" # home and var are extra partitions -part /home --source rootfs --rootfs-dir=${IMAGE_ROOTFS}/home --fstype=ext4 --label home --align 1024 --size 1G -part /var --source rootfs --rootfs-dir=${IMAGE_ROOTFS}/var --fstype=ext4 --label var --align 1024 --size 2G +part /home --source rootfs --rootfs-dir=${IMAGE_ROOTFS}/home --fstype=ext4 --label home --align 1024 --size 1G --extra-space=100M +part /var --source rootfs --rootfs-dir=${IMAGE_ROOTFS}/var --fstype=ext4 --label var --align 1024 --size 2G --extra-space=100M bootloader --ptable gpt --append="console=tty0 console=ttyS0,115200 rootwait earlyprintk"