hbsd-update

#!/bin/sh
#-
# Copyright (c) 2015,2017 HardenedBSD
# Author: Shawn Webb <shawn.webb@hardenedbsd.org>
#
# This work originally sponsored by G2, Inc
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

buildver=""
jailname=""
tmpdir=""
zfsbe=""

backupkern="kernel.old"
configfile="/etc/hbsd-update.conf"
mountpoint="/"
kernel=""

# dnssec variable is yes/no since it's user-visible via
# hbsd-update.conf(5).
dnssec="yes"
dnssec_key="/usr/share/keys/hbsd-update/trusted/dnssec.key"
revoke_dir="/usr/share/keys/hbsd-update/revoked"

ignorever=0
unsigned=0
verbose=0
integriforce=1
no_kernel=0
no_obsolete=0
interactive=0
install_src=0
keeptmp=0
local_resolver=0
nodownload=0
fetchonly=0
nobase=0

update_hash=""

AWK="/usr/bin/awk"
BEADM="/usr/local/sbin/beadm"
CAT="/bin/cat"
CHFLAGS="/bin/chflags"
DRILL="/usr/bin/drill"
ETCUPDATE="/usr/sbin/etcupdate"
FETCH="/usr/bin/fetch"
FIND="/usr/bin/find"
GREP="/usr/bin/grep"
JLS="/usr/sbin/jls"
KLDXREF="/usr/sbin/kldxref"
MKTEMP="/usr/bin/mktemp"
OPENSSL="/usr/bin/openssl"
PWD_MKDB="/usr/sbin/pwd_mkdb"
SED="/usr/bin/sed"
SHA256="/sbin/sha256"
SHA512="/sbin/sha512"
TAIL="/usr/bin/tail"
TAR="/usr/bin/tar"
UNBOUND_HOST="/usr/sbin/unbound-host"

debug_print() {
	echo -e "${1}" >&2
}

usage() {
	debug_print "USAGE: ${0} OPTIONS"
	debug_print "OPTIONS:"
	debug_print "\t-b BEname\tInstall updates to ZFS Boot Environment <BEname>"
	debug_print "\t-c config\tUse a non-default config file"
	debug_print "\t-d\t\tDo not use DNSSEC validation"
	debug_print "\t-f\t\tFetch only"
	debug_print "\t-h\t\tShow this help screen"
	debug_print "\t-I\t\tInteractively remove obsolete files"
	debug_print "\t-i\t\tIgnore version check"
	debug_print "\t-j jailname\tInstall updates to jail <jailname>"
	debug_print "\t-K backupkern\tBackup the previous kernel to <backupkern>"
	debug_print "\t-k kernel\tUse kernel <kernel>"
	debug_print "\t-n\t\tDo not install kernel"
	debug_print "\t-o\t\tDo not remove obsolete files/directories"
	debug_print "\t-r path\tBootstrap root directory <path>"
	debug_print "\t-s\t\tInstall sources (if present)"
	debug_print "\t-t tmpdir\tTemporary directory"
	debug_print "\t-U\t\tAllow unsigned updates"
	debug_print "\t-v version\tUse a different version"
	debug_print "\t-V\t\tVerbose output"
	exit 1
}

sigint_handler() {
	local destroybe

	destroybe=0
	if [ ! -z "${1}" ]; then
		destroybe=${1}
	fi

	debug_print "[-] Caught SIGINT. Cleaning up."

	cleanup
	if [ ${destroybe} -eq 1 ]; then
		destroy_be
	fi

	exit 0
}

get_tmpdir() {
	if [ -z "${tmpdir}" ]; then
		tmpdir=$(${MKTEMP} -d)
	fi

	echo ${tmpdir}

	return 0
}

get_last_field() {
	local data
	local item
	local nitems
	local i

	data="${1}"
	nitems=0
	for item in ${data}; do
		nitems=$((${nitems} + 1))
	done

	i=0
	for item in ${data}; do
		if [ ${i} -eq $((${nitems} - 1)) ]; then
			echo ${item}
		fi
		i=$((${i} + 1))
	done
}

dnssec_check() {
	local resolver_flag
	local is_secure
	local rec
	local res
	local val

	if [ ${local_resolver} -gt 0 ]; then
		resolver_flag="-r"
	fi

	case "${dnssec}" in
		[yY]*)
			if [ ${verbose} -gt 0 ]; then
				debug_print "[*] Looking up version info with DNSSEC enabled."
			fi
			${UNBOUND_HOST} \
				${resolver_flag} \
				-v \
				-t txt \
				-f ${mountpoint}/${dnssec_key} \
				${dnsrec} > ${tmpdir}/resolver.txt

			val=$(${TAIL} -n 1 ${tmpdir}/resolver.txt)
			if ! echo ${val} | grep -qF 'has TXT record'; then
				debug_print "[-] Could not get DNS record."
				return 2
			fi

			if echo ${val} | grep -qF 'failed'; then
				debug_print "[-] DNSSEC validation failed."
				return 2
			fi

			is_secure=$(get_last_field "${val}")
			if [ ! "${is_secure}" = "(secure)" ]; then
				debug_print "[*] DNSSEC validation failed."
				return 2
			fi

			echo ${val} | awk '{print $5;}' | sed 's,",,g'

			;;
		*)
			${DRILL} ${dnsrec} txt | \
				${GREP} -F TXT | \
				${GREP} -vF ';;' | \
				${AWK} '{print $5;}' | \
				${SED} 's,",,g'
			;;
	esac

	return 0
}

get_version() {
	local res
	local dnssec_str

	res=""

	if [ ! -z "${buildver}" ] && [ -z "${update_hash}" ]; then
		# User-specified version
		update_hash=$(echo ${buildver} | ${SED} 's,|, ,g' | ${AWK} '{print $3;}')
		if [ ${#update_hash} -gt 0 ]; then
			buildver=$(echo ${buildver} | ${SED} 's,|, ,g' | ${AWK} '{print $2;}')
		fi
	elif [ -z "${buildver}" ]; then
		# Prefer DNS, fallback to HTTP
		res=$(dnssec_check)
		if [ ${?} -eq 2 ]; then
			debug_print "    [-] Bailing."
			return 1
		fi

		buildver=$(echo ${res} | ${SED} 's,|, ,g' | ${AWK} '{print $2;}')
		update_hash=$(echo ${res} | ${SED} 's,|, ,g' | ${AWK} '{print $3;}')
	fi

	if [ -z "${buildver}" ]; then
		# Attempt to grab the version from the mirror.
		if [ ${verbose} -gt 0 ]; then
			debug_print "[*] Could not get version info from DNS. Falling back to the mirror."
		fi

		res=$(${FETCH} -o - ${baseurl}/update-latest.txt)
		buildver=$(echo ${res} | ${SED} 's,|, ,g' | ${AWK} '{print $2;}')
		update_hash=$(echo ${res} | ${SED} 's,|, ,g' | ${AWK} '{print $3;}')

		if [ -z "${buildver}" ]; then
			return 1
		fi
	fi

	if [ -z "${update_hash}" ]; then
		if [ ${unsigned} -eq 0 ]; then
			debug_print "[-] Hash for the update has not been published. Cannot verify update. Bailing."
			return 1
		fi
	else
		# Validate the hash
		hashalgo=$(echo ${update_hash} | awk -F ':' '{print $1;}')
		hashcheck=$(echo ${update_hash} | awk -F ':' '{print $2;}')

		case "${hashalgo}" in
			sha256)
				if [ ! ${#hashcheck} -eq 64 ]; then
					return 1
				fi
				;;
			sha512)
				if [ ! ${#hashcheck} -eq 128 ]; then
					return 1
				fi
				;;
			*)
				debug_print "[*] Unknown or unsupported hash algorithm: ${hashalgo}"
				return 1
				;;
		esac
	fi

	echo ${buildver}

	if [ ${verbose} -gt 0 ]; then
		debug_print "[*] Latest build: ${buildver}"
	fi

	return 0
}

check_version() {
	local testversion

	if [ ${ignorever} -eq 1 ]; then
		return 0
	fi

	if [ ! -f ${mountpoint}/var/db/hbsd-update/version ]; then
		return 0
	fi

	testversion=$(cat ${mountpoint}/var/db/hbsd-update/version)
	if [ "${buildver}" = "${testversion}" ]; then
		return 1
	fi

	return 0
}

check_jailname() {
	if [ -z "${jailname}" ]; then
		return 0
	fi

	mountpoint=$(${JLS} -j ${jailname} path 2>/dev/null)
	if [ -z "${mountpoint}" ]; then
		debug_print "[-] Jail ${jailname} not found"
		return 1
	fi

	return 0
}

fetch_update() {
	local hashalgo
	local filehash
	local pubhash
	local res

	# Step 1: Download the update archive
	${FETCH} -o ${tmpdir}/update.tar \
		${baseurl}/update-$(get_version).tar
	res=${?}
	if [ ${res} -gt 0 ]; then
		return ${res}
	fi

	if [ ! -z "${update_hash}" ]; then
		# Step 2: Validate the update archive
		hashalgo=$(echo ${update_hash} | awk -F ':' '{print $1;}')
		pubhash=$(echo ${update_hash} | awk -F ':' '{print $2;}')

		case "${hashalgo}" in
			sha256)
				filehash=$(${SHA256} -q ${tmpdir}/update.tar)
				;;
			sha512)
				filehash=$(${SHA512} -q ${tmpdir}/update.tar)
				;;
			*)
				debug_print "[-] Update is signed with unknown hash algorithm: ${hashalgo}"
				;;
		esac

		if [ ! "${filehash}" = "${pubhash}" ]; then
			debug_print "[-] Hash for the update does not match.  Bailing."
			return 1
		fi

		if [ ${verbose} -gt 0 ]; then
			debug_print "[*] Verified hash: ${filehash} = ${pubhash}"
		fi
	fi

	# Step 3: Untar the update archive
	${TAR} -xf ${tmpdir}/update.tar \
		-C ${tmpdir}
	res=${?}
	if [ ${res} -gt 0 ]; then
		return ${res}
	fi

	return 0
}

check_pubkey_validity() {
	local updatehash
	local filehash
	local f

	if [ ${verbose} -gt 0 ]; then
		debug_print "[*] Checking validity of the public key"
	fi

	updatehash=$(${SHA256} -q ${tmpdir}/pubkey.pem)

	for f in $(${FIND} ${mountpoint}/usr/share/keys/hbsd-update/revoked -type f); do
		filehash=$(${SHA256} -q ${f})
		if [ "${filehash}" = "${updatehash}" ]; then
			echo "[-] This update has been signed with a revoked key." >&2
			return 1
		fi
	done

	caopt="-CApath"
	if [ -f ${capath} ]; then
		caopt="-CAfile"
	fi

	${OPENSSL} verify \
		${caopt} ${capath} \
		${tmpdir}/pubkey.pem \
		> /dev/null 2>&1
	res=${?}
	return ${res}
}

validate_file() {
	local res
	local expected_hash
	local computed_hash
	local file
	local defaulterror

	file="${1}"
	defaulterror=1
	if [ ! -z "${2}" ]; then
		defaulterror=${2}
	fi

	if [ -z "${file}" ]; then
		debug_print "[-] validate_file: No file specified."
		return 1
	fi

	if [ ! -f ${tmpdir}/${file} ]; then
		return ${defaulterror}
	fi

	if [ ! -f ${tmpdir}/${file}.sig ]; then
		return 1
	fi

	expected_hash=$(${OPENSSL} rsautl \
	    -verify \
	    -in ${tmpdir}/${file}.sig \
	    -pubin \
	    -inkey ${tmpdir}/pubkey.rsa.pem)
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	computed_hash=$(${SHA512} -q ${tmpdir}/${file})
	if [ ! "${expected_hash}" = "${computed_hash}" ]; then
		return 1
	fi

	return 0
}

check_set_validity() {
	local res
	local checkfiles
	local extrafiles
	local signedhash
	local computedhash

	checkfiles="base.txz etcupdate.tbz skip.txt mtree.tar"
	extrafiles="ObsoleteFiles.txt ObsoleteDirs.txt script.sh"

	if [ ${no_kernel} -eq 0 ]; then
		checkfiles="${checkfiles} kernel-${kernel}.txz"
	fi

	if [ ${integriforce} -gt 0 ]; then
		if [ -f ${tmpdir}/secadm.integriforce.rules ]; then
			extrafiles="${extrafiles} secadm.integriforce.rules"
		fi
	fi

	if [ ${install_src} -gt 0 ]; then
		if [ -f ${tmpdir}/src.txz ]; then
			extrafiles="${extrafiles} src.txz"
		fi
	fi

	${OPENSSL} x509 \
		-in ${tmpdir}/pubkey.pem \
		-pubkey \
		-noout \
		> ${tmpdir}/pubkey.rsa.pem
	res=${?}
	if [ ${res} -gt 0 ]; then
		debug_print "[-] Could not extract public key"
		return 1
	fi

	for file in ${checkfiles}; do
		if [ ${verbose} -gt 0 ]; then
			debug_print "[*] Checking the validity of ${file}"
		fi

		if ! validate_file ${file}; then
			debug_print "[-] ${file} failed to validate"
			return 1
		fi
	done

	# Extra files are optional files that we only care about if
	# they exist. They must be signed if they exist.
	for file in ${extrafiles}; do
		if [ ${verbose} -gt 0 ]; then
			debug_print "[*] Checking the validity of ${file}"
		fi

		if ! validate_file ${file} 0; then
			debug_print "[-] ${file} failed to validate"
			return 1
		fi
	done

	return 0
}

apply_mtree() {
	local res

	if [ ${verbose} -gt 0 ]; then
		debug_print "[*] Applying the mtree"
	fi

	if [ ! -f ${tmpdir}/mtree.tar ]; then
		return 0
	fi

	if [ -d ${tmpdir}/mtree ]; then
		rm -rf ${tmpdir}/mtree
	fi

	mkdir ${tmpdir}/mtree
	if [ ${?} -gt 0 ]; then
		return 1
	fi

	tar -xf ${tmpdir}/mtree.tar -C ${tmpdir}/mtree
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	mtree -eU \
	    -f ${tmpdir}/mtree/BSD.root.dist \
	    -p ${mountpoint}
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	mtree -eU \
	    -f ${tmpdir}/mtree/BSD.usr.dist \
	    -p ${mountpoint}/usr
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	mtree -eU \
	    -f ${tmpdir}/mtree/BSD.include.dist \
	    -p ${mountpoint}/usr/include
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	mtree -eU \
	    -f ${tmpdir}/mtree/BSD.var.dist \
	    -p ${mountpoint}/var
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	if [ -f ${tmpdir}/mtree/BSD.tests.dist ]; then
		mkdir -p ${mountpoint}/usr/tests
		mtree -eU \
		    -f ${tmpdir}/mtree/BSD.tests.dist \
		    -p ${mountpoint}/usr/tests
	fi
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	return 0
}

apply_base() {
	local needsresolve
	local dirs
	local dir
	local res
	local d

	needsresolve=0
	dirs="/bin /sbin /lib /libexec /usr/bin /usr/sbin /usr/lib"

	if [ ${verbose} -gt 0 ]; then
		debug_print "[*] Applying base"
	fi

	for dir in ${dirs}; do
		if [ -d ${mountpoint}/${dir} ]; then
			${CHFLAGS} -R noschg ${mountpoint}/${dir}
			res=${?}
			if [ ${res} -gt 0 ]; then
				return ${res}
			fi
		fi
	done

	${TAR} -xpf ${tmpdir}/base.txz \
		-X ${tmpdir}/skip.txt \
		--exclude ./boot \
		-C ${mountpoint}
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	boottmp=$(env TMPDIR=${tmpdir} ${MKTEMP} -d)
	[ ! -d ${mountpoint}/boot ] && mkdir ${mountpoint}/boot
	${TAR} -xpf ${tmpdir}/base.txz --include ./boot -C ${boottmp}
	${TAR} -c -C ${boottmp}/boot -f - . | \
		(cd ${mountpoint}/boot; ${TAR} -xpf -)
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	rm -rf ${boottmp}

	if [ ${install_src} -gt 0 ]; then
		if [ -f ${tmpdir}/src.txz ]; then
			if [ ${verbose} -gt 0 ]; then
				debug_print "[*] Installing sources"
			fi

			${FIND} ${mountpoint}/usr/src -type f -delete
			res=${?}
			if [ ${res} -gt 0 ]; then
				echo "[-] Removing source files failed." >&2
				return 1
			fi

			for d in $(${FIND} ${mountpoint}/usr/src -type d -depth 1); do
				# Skip the .zfs directory
				if [ ${d} = "${mountpoint}/usr/src/.zfs" ]; then
					continue
				fi

				rm -rf ${d}
				res=${?}
				if [ ${res} -gt 0 ]; then
					echo "[-] Removing source directories failed" >&2
					return 1
				fi
			done

			${TAR} -xpf ${tmpdir}/src.txz \
				-C ${mountpoint}
		fi
	fi

	if [ ${verbose} -gt 0 ]; then
		debug_print "[*] Updating /etc"
	fi

	${ETCUPDATE} -t ${tmpdir}/etcupdate.tbz \
	    -D ${mountpoint} \
	    -I /etc/pwd.db \
	    -I /etc/spwd.db > ${tmpdir}/etcupdate.log 2>&1

	for res in $(awk '{print $1;}' ${tmpdir}/etcupdate.log); do
		if [ "${res}" = "C" ]; then
			needsresolve=1
			break
		fi
	done

	if [ ${needsresolve} -gt 0 ]; then
		debug_print "[*] Manual merges need to be done."
		${ETCUPDATE} resolve -D ${mountpoint}
		res=${?}
		if [ ${res} -gt 0 ]; then
			return 1
		fi
	fi

	if ${GREP} -q passwd ${tmpdir}/etcupdate.log; then
		debug_print "[*] Updating the password database"

		${PWD_MKDB} -d ${mountpoint}/etc -p \
		    ${mountpoint}/etc/master.passwd
		res=${?}
		if [ ${res} -gt 0 ]; then
			echo "[-] Making the password database failed" >&2
			return ${res}
		fi
	fi

	return 0
}

set_kernel_config() {
	local cur_kernel

	if [ ! -z "${kernel}" ]; then
		if [ ! -f "${tmpdir}/kernel-${kernel}.txz" ]; then
			echo "[-] Could not find any applicable kernels" >&2
			return 1
		fi

		return 0
	fi

	cur_kernel=$(uname -v)
	cur_kernel=${cur_kernel##*/}
	cur_kernel=$(echo "${cur_kernel}" | sed 's/ //g')

	f="${tmpdir}/kernel-${cur_kernel}.txz"
	if [ -f "${f}" ]; then
		kernel=${cur_kernel}
	else
		kernel="HARDENEDBSD"
	fi

	if [ ! -f "${tmpdir}/kernel-${kernel}.txz" ]; then
		echo "[-] Could not find any applicable kernels" >&2
		return 1
	fi

	return 0
}

apply_kernel() {
	if [ ${verbose} -gt 0 ]; then
		debug_print "[*] Applying kernel ${kernel}"
	fi

	if [ ! -z "${backupkern}" ]; then
		rm -rf ${mountpoint}/boot/${backupkern}
		cp -pR ${mountpoint}/boot/kernel \
			${mountpoint}/boot/${backupkern}
		res=${?}
		if [ ${res} -gt 0 ]; then
			return ${res}
		fi

		if [ -d ${mountpoint}/usr/lib/debug/boot/kernel ]; then
			rm -rf ${mountpoint}/usr/lib/debug/boot/${backupkern}
			cp -pR ${mountpoint}/usr/lib/debug/boot/kernel \
				${mountpoint}/usr/lib/debug/boot/${backupkern}
			res=${?}
			if [ ${res} -gt 0 ]; then
				return ${res}
			fi
		fi
	fi

	kerntmp=$(env TMPDIR=${tmpdir} ${MKTEMP} -d)

	${TAR} -xpf ${tmpdir}/kernel-${kernel}.txz \
		-X ${tmpdir}/skip.txt \
		--include ./boot \
		-C ${kerntmp}
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	${TAR} -cp -C ${kerntmp}/boot -f - . | \
		(cd ${mountpoint}/boot; ${TAR} -xpf -)
	res=${?}
	if [ ${res} -gt 0 ]; then
		return ${res}
	fi

	rm -rf ${kerntmp}

	${KLDXREF} ${mountpoint}/boot/kernel
	res=${?}
	if [ ${res} -gt 0 ]; then
		return 1
	fi

	return 0
}

apply_integriforce() {
	local res
	local f

	debug_print "[*] Applying Integriforce rules"

	f="${mountpoint}/etc/secadm.d/base.integriforce.rules"

	if [ -f ${tmpdir}/secadm.integriforce.rules ]; then
		if [ ! -d ${mountpoint}/etc/secadm.d ]; then
			mkdir ${mountpoint}/etc/secadm.d
			res=${?}
			if [ ${res} -gt 0 ]; then
				return 1
			fi
		fi

		if [ -f ${mountpoint}/etc/secadm.d/base.integriforce.rules ]; then
			chflags noschg ${f}
			res=${?}
			if [ ${res} -gt 0 ]; then
				return 1
			fi

			chmod 0600 ${f}
			res=${?}
			if [ ${res} -gt 0 ]; then
				return 1
			fi
		fi

		cp ${tmpdir}/secadm.integriforce.rules ${f}
		res=${?}
		if [ ${res} -gt 0 ]; then
			return 1
		fi

		chmod 0400 ${f}
		res=${?}
		if [ ${res} -gt 0 ]; then
			return 1
		fi

		chflags schg ${f}
		res=${?}
		if [ ${res} -gt 0 ]; then
			return 1
		fi
	fi

	return 0
}

remove_obsolete() {
	if [ ${verbose} -gt 0 ]; then
		debug_print "[*] Removing obsolete files"
	fi

	if [ -f ${tmpdir}/ObsoleteFiles.txt ]; then
		for file in $(cat ${tmpdir}/ObsoleteFiles.txt); do
			if [ -f ${mountpoint}/${file} ]; then
				if [ ${interactive} -gt 0 ]; then
					read -p "Remove ${mountpoint}/${file} (Y/n)? " val
					case "${val}" in
						[Nn]*)
							continue
							;;
					esac
				fi

				if [ ${verbose} -gt 0 ]; then
					debug_print "    [+] Removing ${mountpoint}/${file}"
				fi

				rm -f ${mountpoint}/${file}
			fi
		done
	fi

	if [ -f ${tmpdir}/ObsoleteDirs.txt ]; then
		for file in $(cat ${tmpdir}/ObsoleteDirs.txt); do
			if [ -e ${mountpoint}/${file} ]; then
				if [ ${verbose} -gt 0 ]; then
					debug_print "    [+] Removing ${mountpoint}/${file}"
				fi

				rm -rf ${mountpoint}/${file}
			fi
		done
	fi

	return 0
}

create_be() {
	if [ -z "${zfsbe}" ]; then
		return 0
	fi

	${BEADM} create ${zfsbe}
	res=${?}
	if [ ${res} -gt 0 ]; then
		return ${res}
	fi

	mountpoint=$(${MKTEMP} -d)
	${BEADM} mount ${zfsbe} ${mountpoint}
	res=${?}
	if [ ${res} -gt 0 ]; then
		return ${res}
	fi

	return 0
}

cache_version() {
	# Cache the version number so that we can verify it against
	# future update requests.
	if [ ! -d ${mountpoint}/var/db/hbsd-update ]; then
		mkdir -p ${mountpoint}/var/db/hbsd-update
		res=${?}
		if [ ${res} -gt 0 ]; then
			return ${res}
		fi
	fi

	echo ${buildver} > ${mountpoint}/var/db/hbsd-update/version
}

activate_be() {
	if [ -z "${zfsbe}" ]; then
		return 0
	fi

	${BEADM} umount ${zfsbe}
	res=${?}
	if [ ${res} -gt 0 ]; then
		return ${res}
	fi

	${BEADM} activate ${zfsbe}
	res=${?}
	if [ ${res} -gt 0 ]; then
		return ${res}
	fi

	return 0
}

destroy_be() {
	if [ -z "${zfsbe}" ]; then
		return 0
	fi

	${BEADM} umount ${zfsbe}
	${BEADM} destroy -F ${zfsbe}
	return ${?}
}

cleanup() {
	if [ ${keeptmp} -eq 0 ]; then
		rm -rf ${tmpdir}
	else
		debug_print "[*] Temp directory kept at: ${tmpdir}"
	fi
}

check_sanity() {
	if [ ! -f ${configfile} ]; then
		debug_print "[-] Configuration file missing"
		exit 1
	fi

	. ${configfile}

	if [ -z "${baseurl}" ]; then
		debug_print "[-] Missing setting: baseurl"
		exit 1
	fi

	if [ ${unsigned} -eq 0 ] && [ -z "${capath}" ]; then
		debug_print "[-] Missing setting: capath"
		exit 1
	fi

	if [ ! -z "${zfsbe}" ] && [ ! -z "${jailname}" ]; then
		debug_print "[-] ZFS BE and Jail options are mutually exclusive"
		exit 1
	fi

	if [ ${fetchonly} -gt 0 ] && [ ${nodownload} -gt 0 ]; then
		debug_print "[-] Fetch only and no download options are mutually exclusive"
		exit 1
	fi

	# FreeBSD / HardenedBSD 12 introduced bectl in base. bectl
	# provides a beadm-compatible utility for managing ZFS Boot
	# Environments (BEs). Since the majority of HardenedBSD users
	# are on 11-STABLE, prefer beadm over bectl. Hopefully, bectl
	# will one day exist on 11-STABLE.
	if [ ! -z "${zfsbe}" ] && [ ! -x ${BEADM} ]; then
		if [ -x /sbin/bectl ]; then
			BEADM=/sbin/bectl
		else
			debug_print "[-] Please install sysutils/beadm"
			exit 1
		fi
	fi
}

report_version() {
	get_tmpdir > /dev/null
	get_version
	if [ ! ${?} -eq 0 ]; then
		echo "[-] Could not get remote version number" >&2
		cleanup
		exit 1
	fi

	if [ -f ${mountpoint}/var/db/hbsd-update/version ]; then
		echo "[+] Local version: $(cat ${mountpoint}/var/db/hbsd-update/version)"
	fi

	echo -n "[+] Remote version: ${buildver}"
	
	if [ ! -z "${update_hash}" ]; then
		echo -n " $(echo ${update_hash} | sed 's,:, ,')"
	fi

	echo

	cleanup
	exit 0
}

pre_install_hook() {
	return 0
}

post_install_hook() {
	return 0
}

main() {
	local do_report_version
	local local_kernel

	do_report_version=0
	local_kernel=""
	no_kernel=0

	while getopts 'dfhinosBCDITUVb:c:j:K:k:r:t:u:v:' opt; do
		case "${opt}" in
			b)
				zfsbe="${OPTARG}"
				;;
			B)
				nobase=1
				;;
			c)
				configfile="${OPTARG}"
				;;
			C)
				do_report_version=1
				;;
			d)
				dnssec="no"
				;;
			D)
				nodownload=1
				;;
			f)
				fetchonly=1
				;;
			i)
				ignorever=1
				;;
			I)
				interactive=1
				;;
			j)
				jailname="${OPTARG}"
				;;
			K)
				backupkern="${OPTARG}"
				;;
			k)
				local_kernel="${OPTARG}"
				;;
			n)
				no_kernel=1
				;;
			o)
				no_obsolete=1
				;;
			r)
				mountpoint="${OPTARG}"
				;;
			s)
				install_src=1
				;;
			t)
				tmpdir="${OPTARG}"
				;;
			T)
				keeptmp=1
				;;
			U)
				unsigned=1
				;;
			v)
				buildver="${OPTARG}"
				;;
			V)
				verbose=1
				;;
			*)
				usage
				;;
		esac
	done

	check_sanity
	check_jailname
	res=${?}
	if [ ${res} -gt 0 ]; then
		exit 1
	fi

	if [ ${do_report_version} -gt 0 ]; then
		report_version
	fi

	if [ ! -z "${local_kernel}" ]; then
		kernel=${local_kernel}
	fi

	if [ ! -d ${mountpoint} ]; then
		debug_print "[-] ${mountpoint} does not exist"
		cleanup
		exit 1
	fi

	trap sigint_handler INT

	if [ -z "${tmpdir}" ]; then
		get_tmpdir > /dev/null
	fi

	get_version
	res=${?}
	if [ ${res} -gt 0 ]; then
		debug_print "[*] Could not get the version number"
		if [ -f ${tmpdir}/resolver.txt ]; then
			debug_print "[*] Raw DNS result:"
			${CAT} ${tmpdir}/resolver.txt
		fi
		cleanup
		exit 1
	fi

	check_version
	res=${?}
	if [ ${res} -gt 0 ]; then
		debug_print "[*] This system is already on the latest version."
		cleanup
		exit 0
	fi

	if [ ${nodownload} -eq 0 ]; then
		fetch_update
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			exit 1
		fi
	fi

	if [ ${fetchonly} -gt 0 ]; then
		exit 0
	fi

	if [ ${no_kernel} -eq 0 ]; then
		set_kernel_config
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			exit 1
		fi
	fi

	if [ ${unsigned} -eq 0 ]; then
		check_pubkey_validity
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			debug_print "[*] Public key failed to validate."
			exit 1
		fi

		check_set_validity
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			debug_print "[*] Public key failed to validate."
			exit 1
		fi
	fi

	if [ -f ${tmpdir}/script.sh ]; then
		. ${tmpdir}/script.sh
	fi

	pre_install_hook
	res=${?}
	if [ ${res} -gt 0 ]; then
		cleanup
		exit 1
	fi

	create_be
	res=${?}
	if [ ${res} -gt 0 ]; then
		cleanup
		destroy_be
		exit 1
	fi

	trap 'sigint_handler 1' INT

	if [ ${nobase} -eq 0 ]; then
		apply_mtree
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			destroy_be
			exit 1
		fi

		apply_base
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			destroy_be
			exit 1
		fi
	fi

	if [ ${no_kernel} -eq 0 ]; then
		apply_kernel
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			destroy_be
			exit 1
		fi
	fi

	if [ ${no_obsolete} -eq 0 ]; then
		remove_obsolete
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			destroy_be
			exit 1
		fi
	fi

	if [ ${integriforce} -gt 0 ]; then
		apply_integriforce
		res=${?}
		if [ ${res} -gt 0 ]; then
			cleanup
			destroy_be
			exit 1
		fi
	fi

	cache_version
	res=${?}
	if [ ${res} -gt 0 ]; then
		cleanup
		destroy_be
		exit 1
	fi

	post_install_hook
	res=${?}
	if [ ${res} -gt 0 ]; then
		cleanup
		destroy_be
		exit 1
	fi

	activate_be
	res=${?}
	if [ ${res} -gt 0 ]; then
		cleanup
		destroy_be
		exit 1
	fi

	cleanup
	exit 0
}

main "${@}"