blob: 12616b41c9d3258ebdb2c94ba23b5ca38512bf19 [file] [log] [blame] [edit]
#!/bin/sh -u
# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Run TPM diagnostics in recovery mode, and attempt to fix problems. This is
# specific to devices with chromeos firmware.
#
# Most of the diagnostics examine the TPM state and try to fix it. This may
# require clearing TPM ownership.
tpmc=${USR_BIN:=/usr/bin}/tpmc
crossystem=${USR_BIN}/crossystem
dot_recovery=${DOT_RECOVERY:=/mnt/stateful_partition/.recovery}
awk=/usr/bin/awk
initctl=/sbin/initctl
daemon_was_running=
err=0
secdata_firmware=0x1007
secdata_kernel=0x1008
tpm2_target() {
# This is not an ideal way to tell if we are running on a tpm2 target, but
# it will have to do for now.
if [ -f "/etc/init/trunksd.conf" ]; then
return 0
else
return 1
fi
}
use_v0_secdata_kernel() {
local fwid="$(crossystem ro_fwid)"
local major="$(printf "$fwid" | cut -d. -f2)"
local minor="$(printf "$fwid" | cut -d. -f3)"
# TPM1 firmware never supports the v1 kernel space format.
if ! tpm2_target; then
return 0
fi
# First some validity checks: X -eq X checks that X is a number. cut may
# return the whole string if no delimiter found, so major != minor checks that
# the version was at least somewhat correctly formatted.
if [ $major -eq $major ] && [ $minor -eq $minor ] && [ $major -ne $minor ]; then
# Now what we really care about: is this firmware older than CL:2041695?
if [ $major -lt 12953 ]; then
return 0
else
return 1
fi
else
log "Cannot parse FWID. Assuming local build that supports v1 kernel space."
return 1
fi
}
log() {
echo "$*"
}
quit() {
log "ERROR: $*"
restart_daemon_if_needed
log "exiting"
exit 1
}
log_tryfix() {
log "$*: attempting to fix"
}
log_error() {
err=$((err + 1))
log "ERROR: $*"
}
log_warn() {
log "WARNING: $*"
}
tpm_clear_and_reenable () {
$tpmc clear
# The below commands are are no-op on tpm2, but let's keep them here for
# both TPM versions in case they are implemented in the future for
# version 2.
$tpmc enable
$tpmc activate
}
write_space () {
# do not quote "$2", as we mean to expand it here
if ! $tpmc write $1 $2; then
log_error "writing to $1 failed"
else
log "$1 written successfully"
fi
}
reset_ro_space () {
local index=$1
local bytes="$2"
local size=$(printf "$bytes" | wc -w)
local permissions=0x8001
if tpm2_target; then
log "Cannot redefine RO space for TPM2 (b/140958855). Let's just hope it looks good..."
else
if ! $tpmc definespace $index $size $permissions; then
log_error "could not redefine RO space $index"
# try writing it anyway, just in case it works...
fi
fi
write_space $index "$bytes"
}
reset_rw_space () {
local index=$1
local bytes="$2"
local size=$(printf "$bytes" | wc -w)
local permissions=0x1
if tpm2_target; then
permissions=0x40050001
fi
if ! $tpmc definespace $index $size $permissions; then
log_error "could not redefine RW space $index"
# try writing it anyway, just in case it works...
fi
write_space $index "$bytes"
}
restart_daemon_if_needed() {
if [ "$daemon_was_running" = 1 ]; then
log "Restarting ${DAEMON}..."
$initctl start "${DAEMON}" >/dev/null
fi
}
# ------------
# MAIN PROGRAM
# ------------
# validity check: are we executing in a recovery image?
if [ -e $dot_recovery ]; then
quit "This is a developer utility, it should never run on a (production) recovery image"
fi
# Did the firmware keep the TPM unlocked?
if ! $($crossystem mainfw_type?recovery); then
quit "You must put a test image on a USB stick and boot it in recovery mode (this means Esc+Refresh+Power, *not* Ctrl-U!) to run this"
fi
if tpm2_target; then
DAEMON="trunksd"
else
DAEMON="tcsd"
fi
# TPM daemon may or may not be running
log "Stopping ${DAEMON}..."
if $initctl stop "${DAEMON}" >/dev/null 2>/dev/null; then
daemon_was_running=1
log "done"
else
daemon_was_running=0
log "(was not running)"
fi
# Is the state of the PP enable flags correct?
if ! tpm2_target; then
if ! ($tpmc getpf | grep -q "physicalPresenceLifetimeLock 1" &&
$tpmc getpf | grep -q "physicalPresenceHWEnable 0" &&
$tpmc getpf | grep -q "physicalPresenceCMDEnable 1"); then
log_tryfix "bad state of physical presence enable flags"
if $tpmc ppfin; then
log "physical presence enable flags are now correctly set"
else
quit "could not set physical presence enable flags"
fi
fi
# Is physical presence turned on?
if $tpmc getvf | grep -q "physicalPresence 0"; then
log_tryfix "physical presence is OFF, expected ON"
# attempt to turn on physical presence
if $tpmc ppon; then
log "physical presence is now on"
else
quit "could not turn physical presence on"
fi
fi
else
if ! $tpmc getvf | grep -q 'phEnable 1'; then
quit "Platform Hierarchy is disabled, TPM can't be recovered"
fi
fi
# I never learned what this does, but it's probably good just in case...
tpm_clear_and_reenable
# Reset firmware and kernel spaces to default (rollback version 1/1)
reset_ro_space $secdata_firmware "02 0 1 0 1 0 0 0 0 4f"
if use_v0_secdata_kernel; then
reset_rw_space $secdata_kernel "02 4c 57 52 47 1 0 1 0 0 0 0 55"
else
reset_rw_space $secdata_kernel "10 28 0c 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0"
fi
restart_daemon_if_needed
if [ "$err" -eq 0 ]; then
log "TPM has successfully been reset to factory defaults"
else
log_error "TPM was not fully recovered."
exit 1
fi