tastytea/hashboot
1
0
Fork 1
Code Issues Pull Requests Releases 1 Wiki Activity
37a4399293
hashboot/hashboot

236 lines
8.7 KiB
Bash
Executable File
Raw Blame History

#!/bin/bash
#Hashes all files in /boot to check them during early boot
#Exit codes: 0 = success, 1 = checksum mbr mismatch, 2 = checksum /boot mismatch,
#3 = checksum mbr/boot mismatch, 4 = not root, 5 = no hasher found, 6 = wrong usage,
#7 = write error, 8 = dd error, 9 = file not found
#10 = bios mismatch, 11 == mbr&bios mismatch, 12 = files&bios mismatch
#13 = mbr&bios&files mismatch
###################################################################################
# "THE HUG-WARE LICENSE" (Revision 1): #
# xo <xo@rotce.de> and tastytea <tastytea@tastytea.de> wrote these files. As long #
# as you retain this notice you can do whatever you want with this stuff. If we #
# meet some day, and you think this stuff is worth it, you can give us a hug. #
###################################################################################
VERSION="0.9.0"
PATH="/bin:/usr/bin:/sbin:/usr/sbin:${PATH}"
DIGEST_FILE="/var/lib/hashboot.digest"
DIGEST_FILE_TMP="/tmp/hashboot.digesttmp"
LOG_FILE="/tmp/hashboot.log"
MBR_DEVICE="/dev/sda"
MBR_SIZE=1024
MBR_TMP="/tmp/mbr"
BIOS_TMP="/tmp/bios"
BACKUP_FILE="/var/cache/boot-backup.tar"
HASHER=""
BOOT_MOUNTED=0
CONFIG_FILE="/etc/hashboot.cfg"
COUNTER=0
DD_STATUS="none"
PROGRAMMER="no" #standard change enables bios mode
#Umount /boot if we mounted it, exit with given exit code
die ()
{
if [ ${BOOT_MOUNTED} -gt 0 ]
then
umount /boot
fi
[ -z "${2}" ] || echo "${2}" >&2
exit ${1}
}
write_hashes ()
{
#Write header to ${1}
echo "#hashboot ${VERSION} - Algorithm: $(basename ${HASHER})" > ${1}
#Write MBR of MBR_DEVICE to ${1}
dd if=${MBR_DEVICE} of=${MBR_TMP} bs=${MBR_SIZE}K count=1 status=${DD_STATUS} || die 8
#Write bios to ${1}
#if we set an programmer chip in config, read bios and write it to digestfile.
if [ ! ${PROGRAMMER} == "no" ]; then
flashrom --programmer ${PROGRAMMER} -r ${BIOS_TMP} > /dev/null 2>&1
${HASHER} ${BIOS_TMP} >> ${1}
fi
#Write hashes of all regular files to ${1}
${HASHER} ${MBR_TMP} >> ${1}
find /boot -type f -exec ${HASHER} --binary {} >> ${1} +
}
#If we're not root: exit
if [ ${UID} -ne 0 ]
then
die 4 "You have to be root"
fi
#If /boot is in fstab but not mounted: mount, mark as mounted
if grep -q '/boot' /etc/fstab && ! grep -q /boot /etc/mtab
then
mount /boot
BOOT_MOUNTED=1
fi
# Debian < 8 check
if which lsb_release > /dev/null 2>&1 && [ "$(lsb_release -si)" == "Debian" ] && [ $(lsb_release -sr | cut -d'.' -f1) -lt 8 ]
then
DD_STATUS="noxfer"
fi
#Look for config file and set ${MBR_DEVICE}.
if [ -f ${CONFIG_FILE} ]
then
source ${CONFIG_FILE} || die 9 "Error reading config file"
#If not found, create one and ask for ${MBR_DEVICE}
else
#Create ${CONFIG_FILE} with defaults if noninterctive
if [ -t "0" ]
then
echo -n "Which device contains the MBR? [/dev/sda] "
read -r MBR_DEVICE
[ -z "${MBR_DEVICE}" ] && MBR_DEVICE="/dev/sda"
echo "#Device with the MBR on it" > ${CONFIG_FILE}
echo "MBR_DEVICE=${MBR_DEVICE}" >> ${CONFIG_FILE}
echo -n "Where should backup file be stored? [/var/cache/boot-backup.tar] "
read -r BACKUP_FILE
[ -z "${BACKUP_FILE}" ] && BACKUP_FILE="/var/cache/boot-backup.tar"
echo "#Where the Backup files are stored" >> ${CONFIG_FILE}
echo "BACKUP_FILE=${BACKUP_FILE}" >> ${CONFIG_FILE}
echo -n "Include BIOS check? (y/n)"
read b
if [ ${b} == "y"]; then
if which flashrom; then
flashrom
echo -n "Which programmer? (eg. internal)"
read p
echo "PROGRAMMER=${p}" >> ${CONFIG_FILE}
else
echo "No flashrom found. You need to install it."
echo "PROGRAMMER=${PROGRAMMER}" >> ${CONFIG_FILE}
fi
else
echo "PROGRAMMER=no" >> ${CONFIG_FILE}
fi
else
echo "#Device with the MBR on it" > ${CONFIG_FILE}
echo "MBR_DEVICE=${MBR_DEVICE}" >> ${CONFIG_FILE}
echo "#Where the Backup files are stored" >> ${CONFIG_FILE}
echo "BACKUP_FILE=${BACKUP_FILE}" >> ${CONFIG_FILE}
echo "PROGRAMMER=${PROGRAMMER}" >> ${CONFIG_FILE}
fi
fi
# Find out where the first partition starts and set ${MBR_SIZE} in KiB
sectorsize=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep '^Units' | awk '{print $8}' )
if [ "${sectorsize}" == "=" ] # Older versions of util-linux
then
sectorsize=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep '^Units' | awk '{print $9}' )
fi
startsector=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep -A1 'Device' | tail -n1 | awk '{print $2}' )
if [ "${startsector}" == "*" ] # If partition is marked as boot, read next field
then
startsector=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep -A1 'Device' | tail -n1 | awk '{print $3}' )
fi
MBR_SIZE=$(expr ${sectorsize} \* ${startsector} / 1024)
if [ ${?} != 0 ]
then
echo "Something went wrong. Most likely your partition table is corrupt." >&2
die 1 "You have to recover the MBR manually by copying the mbr from ${BACKUP_FILE}"
fi
if [ "${1}" == "index" ]
then
#Try different hashers, use the most secure
HASHER=$(/usr/bin/which sha512sum 2> /dev/null)
test -z "${HASHER}" && HASHER=$(/usr/bin/which sha384sum 2> /dev/null)
test -z "${HASHER}" && HASHER=$(/usr/bin/which sha256sum 2> /dev/null)
test -z "${HASHER}" && HASHER=$(/usr/bin/which sha224sum 2> /dev/null)
#It gets insecure below here, but better than nothing?
test -z "${HASHER}" && HASHER=$(/usr/bin/which sha1sum 2> /dev/null)
test -z "${HASHER}" && HASHER=$(/usr/bin/which md5sum 2> /dev/null)
#If we found no hasher: exit
[ -z "${HASHER}" ] && die 5 "No hash calculator found"
#Exists ${DIGEST_FILE}, if true run do magic, else write ${DIGEST_FILE}
if [ -f ${DIGEST_FILE} ]
then
#Collect mbr and /boot hashes and write to $DIGEST_FILE_TMP
write_hashes $DIGEST_FILE_TMP
#Compare $DIGEST_FILE_TMP against ${DIGEST_FILE} and exit, when fine. Otherwise do magic.
if diff -q --ignore-matching-lines='#hashboot' ${DIGEST_FILE} ${DIGEST_FILE_TMP} ;
then
die 0
else
for file in $(diff ${DIGEST_FILE} ${DIGEST_FILE_TMP} | grep -v '#hashboot' | grep '<' | cut -d'*' -f2 | sed 's/\ /\\ /g' );
do
#delete from tar
tar --delete -v -P -f $BACKUP_FILE $file
done
for file in $(diff ${DIGEST_FILE} ${DIGEST_FILE_TMP} | grep -v '#hashboot' | grep '>' | cut -d'*' -f2 | sed 's/\ /\\ /g' );
do
tar -r -v -P -f $BACKUP_FILE $file
done
fi
#nur, wenn das updaten des Backups geklappt hat. *im Hinterkopf behalt*
mv ${DIGEST_FILE_TMP} ${DIGEST_FILE}
else
write_hashes $DIGEST_FILE
tar -cpPf ${BACKUP_FILE} ${BIOS} ${MBR_TMP} /boot ${DIGEST_FILE} || die 7 "Error writing ${BACKUP_FILE}"
echo "Backup written to ${BACKUP_FILE}"
fi
elif [ "${1}" == "check" ]
then
[ -f ${DIGEST_FILE} ] || die 9 "No digestfile"
HASHER=$(head -n1 ${DIGEST_FILE} | awk '{print $5}')
dd if=${MBR_DEVICE} of=${MBR_TMP} bs=${MBR_SIZE}K count=1 status=${DD_STATUS} || die 8
flashrom --programmer ${PROGRAMMER} -r ${BIOS_TMP} > /dev/null 2>&1
if ! grep ${MBR_TMP} ${DIGEST_FILE} | ${HASHER} --check --warn --quiet --strict | tee ${LOG_FILE}
then
echo " !! TIME TO PANIK: MBR WAS MODIFIED !!"
COUNTER=$((COUNTER + 1))
fi
if ! grep -v ${MBR_TMP} ${DIGEST_FILE} | grep -v ${BIOS_TMP} | ${HASHER} --check --warn --quiet --strict | tee -a ${LOG_FILE}
then
echo " !! TIME TO PANIK: AT LEAST 1 FILE WAS MODIFIED !!"
COUNTER=$((COUNTER + 2))
die $COUNTER
fi
#if we set an programmer chip in config, find line with hash for bios and compare. if smthg wrong, panic
if [ ! ${PROGRAMMER} == "no" ]; then
if grep ${BIOS_TMP} ${DIGEST_FILE} | ${HASHER} --check --warn --quiet --strict | tee -a ${LOG_FILE}
then
echo " !! TIME TO PANIK: BIOS WAS MODIFIED !!"
COUNTER=$((COUNTER + 10))
die $COUNTER
fi
fi
elif [ "${1}" == "recover" ]
then
echo "Restoring files from backup... (type yes or no for each file)"
#For each failed file: ask if it should be recovered from backup
for file in $(cut -d: -f1 ${LOG_FILE})
do
tar -xpPvwf ${BACKUP_FILE} ${file}
[ $? != 0 ] && echo "Error restoring ${file} from backup, continuing" >&2
#If the MBR is to be recovered, copy to ${MBR_DEVICE}
if [ "${file}" == ${MBR_TMP} ]
then
cp ${MBR_TMP} ${MBR_DEVICE}
[ $? != 0 ] && echo "Error restoring MBR from backup, continuing" >&2
fi
done
else
die 6 "Usage: ${0} index|check|recover"
fi
die 0
Reference in New Issue View Git Blame Copy Permalink