heads/initrd/bin/oem-factory-reset
tlaurion 94476bb470
Merge pull request #747 from MrChromebox/factory_reset_no_tpm
oem-factory-reset: Handle non-TPM case
2020-06-28 15:26:16 -04:00

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#!/bin/sh
# Automated setup of TPM, GPG keys, and disk
set -o pipefail
# use TERM to exit on error
trap "exit 1" TERM
export TOP_PID=$$
## Static local variables
CLEAR="--clear"
CONTINUE="--yes-button Continue"
CANCEL="--no-button Cancel"
HEIGHT="150"
WIDTH="220"
USER_PIN_DEF=123456
ADMIN_PIN_DEF=12345678
TPM_PASS_DEF=12345678
CUSTOM_PASS=""
GPG_USER_NAME="OEM Key"
GPG_KEY_NAME=`date +%Y%m%d%H%M%S`
GPG_USER_MAIL="oem-${GPG_KEY_NAME}@example.com"
GPG_USER_COMMENT="OEM-generated key"
## External files sourced
. /etc/functions
. /tmp/config
## functions
die() {
local msg=$1
if [ -n "$msg" ]; then
echo -e "\n$msg"
fi
kill -s TERM $TOP_PID
exit 1
}
whiptail_error()
{
local msg=$1
if [ "$msg" = "" ]; then
die "whiptail error: An error msg is required"
fi
whiptail --msgbox "${msg}\n\n" $WIDTH $HEIGHT $CONFIG_ERROR_BG_COLOR --title "Error"
}
whiptail_error_die()
{
whiptail_error "$@"
die
}
gpg_key_reset()
{
# Factory reset GPG card
{
echo admin
echo factory-reset
echo y
echo yes
} | gpg --command-fd=0 --status-fd=1 --pinentry-mode=loopback --card-edit \
> /tmp/gpg_card_edit_output 2>/dev/null
if [ $? -ne 0 ]; then
ERROR=`cat /tmp/gpg_card_edit_output`
whiptail_error_die "GPG Key factory reset failed!\n\n$ERROR"
fi
# Generate OEM GPG keys
{
echo admin
echo generate
echo n
echo ${ADMIN_PIN_DEF}
echo ${USER_PIN_DEF}
echo 0
echo y
echo ${GPG_USER_NAME}
echo ${GPG_USER_MAIL}
echo ${GPG_USER_COMMENT}
} | gpg --command-fd=0 --status-fd=2 --pinentry-mode=loopback --card-edit \
> /tmp/gpg_card_edit_output 2>/dev/null
if [ $? -ne 0 ]; then
ERROR=`cat /tmp/gpg_card_edit_output`
whiptail_error_die "GPG Key automatic keygen failed!\n\n$ERROR"
fi
}
gpg_key_change_pin()
{
# 1 = user PIN, 3 = admin PIN
PIN_TYPE=$1
PIN_ORIG=$2
PIN_NEW=$3
# Change PIN
{
echo admin
echo passwd
echo ${PIN_TYPE}
echo ${PIN_ORIG}
echo ${PIN_NEW}
echo ${PIN_NEW}
echo q
echo q
} | gpg --command-fd=0 --status-fd=2 --pinentry-mode=loopback --card-edit \
> /tmp/gpg_card_edit_output 2>/dev/null
if [ $? -ne 0 ]; then
ERROR=`cat /tmp/gpg_card_edit_output`
whiptail_error_die "GPG Key PIN change failed!\n\n$ERROR"
fi
}
generate_checksums()
{
# ensure /boot mounted
if ! grep -q /boot /proc/mounts ; then
mount -o rw /boot || whiptail_error_die "Unable to mount /boot"
else
mount -o remount,rw /boot || whiptail_error_die "Unable to mount /boot"
fi
# clear any existing checksums/signatures
rm /boot/kexec* 2>/dev/null
# create Heads TPM counter
if [ "$CONFIG_TPM" = "y" ]; then
tpm counter_create \
-pwdo "$TPM_PASS_DEF" \
-pwdc '' \
-la -3135106223 \
| tee /tmp/counter \
|| whiptail_error_die "Unable to create TPM counter"
TPM_COUNTER=`cut -d: -f1 < /tmp/counter`
# increment TPM counter
increment_tpm_counter $TPM_COUNTER >/dev/null 2>&1 \
|| whiptail_error_die "Unable to increment tpm counter"
# create rollback file
sha256sum /tmp/counter-$TPM_COUNTER > /boot/kexec_rollback.txt 2>/dev/null \
|| whiptail_error_die "Unable to create rollback file"
else
## needs to exist for initial call to unseal-hotp
echo "0" > /boot/kexec_hotp_counter
fi
# set default boot option
set_default_boot_option
# generate hashes
find /boot -type f ! -name '*kexec*' \
| xargs sha256sum > /boot/kexec_hashes.txt 2>/dev/null \
|| whiptail_error_die "Error generating kexec hashes"
param_files=`find /boot/kexec*.txt`
[ -z "$param_files" ] \
&& whiptail_error_die "No kexec parameter files to sign"
# sign kexec boot files
if sha256sum $param_files 2>/dev/null | gpg \
--pinentry-mode loopback \
--passphrase "$USER_PIN_DEF" \
--digest-algo SHA256 \
--detach-sign \
-a \
> /boot/kexec.sig 2>/tmp/error; then
# successful - update the validated params
if ! check_config /boot >/dev/null 2>/tmp/error ; then
cat /tmp/error
ret=1
else
ret=0
fi
else
cat /tmp/error
ret=1
fi
# done writing to /boot, switch back to RO
mount -o ro,remount /boot
if [ $ret = 1 ] ; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Error signing kexec boot files:\n\n$ERROR"
fi
}
set_default_boot_option()
{
option_file="/tmp/kexec_options.txt"
tmp_menu_file="/tmp/kexec/kexec_menu.txt"
hash_file="/boot/kexec_default_hashes.txt"
mkdir -p /tmp/kexec/
rm $option_file 2>/dev/null
# parse boot options from grub.cfg
for i in `find /boot -name "grub.cfg"`; do
kexec-parse-boot "/boot" "$i" >> $option_file
done
[ ! -r $option_file ] \
&& whiptail_error_die "Failed to parse any boot options"
# sort boot options
sort -r $option_file | uniq > $tmp_menu_file
## save first option as default
entry=`head -n 1 $tmp_menu_file | tail -1`
# clear existing default configs
rm "/boot/kexec_default.*.txt" 2>/dev/null
# write new config
echo "$entry" > /boot/kexec_default.1.txt
# validate boot option
cd /boot && /bin/kexec-boot -b "/boot" -e "$entry" -f \
| xargs sha256sum > $hash_file 2>/dev/null \
|| whiptail_error_die "Failed to create hashes of boot files"
}
## main script start
# check for args
if [ "$1" != "" ]; then
title_text=$1
else
title_text="OEM Factory Reset"
fi
if [ "$2" != "" ]; then
bg_color=$2
else
bg_color=""
fi
# show warning prompt
if [ "$CONFIG_TPM" = "y" ]; then
TPM_STR=" * ERASE the TPM and reset it with a default password\n"
else
TPM_STR=""
fi
if ! whiptail --yesno "
This operation will automatically:\n\n
$TPM_STR
* ERASE any keys or passwords on the GPG smart card,\n
reset it to a factory state, and generate new keys\n
* Add the new GPG key to the firmware and reflash it\n
* Sign all of the files in /boot with the new GPG key\n\n
It requires that you already have an OS installed on a\n
dedicated /boot partition. Do you wish to continue?\n" \
$WIDTH $HEIGHT $CONTINUE $CANCEL $CLEAR $bg_color --title "$title_text" ; then
exit 1
fi
# Prompt to change default passwords
echo -e -n "Would you like to set a custom password? [y/N]: "
read -n 1 prompt_output
echo
if [ "$prompt_output" == "y" \
-o "$prompt_output" == "Y" ] \
; then
echo -e "\nThe custom password will be used for the
TPM admin and GPG user/admin passwords.
It must be at least 8 characters in length.\n"
CUSTOM_PASS=""
echo
while [[ ${#CUSTOM_PASS} -lt 8 ]] ; do
echo -e -n "Enter the custom password: "
read CUSTOM_PASS
done
echo
TPM_PASS_DEF=$CUSTOM_PASS
fi
# Prompt to change default GnuPG key information
echo -e -n "Would you like to set custom user information for the GnuPG key? [y/N]: "
read -n 1 prompt_output
echo
if [ "$prompt_output" == "y" \
-o "$prompt_output" == "Y" ] \
; then
echo -e "\n\n"
echo -e "We will generate a GnuPG (PGP) keypair identifiable with the following text form:"
echo -e "Real Name (Comment) email@address.org"
echo -e "\nEnter your Real Name (At least 5 characters long):"
read -r GPG_USER_NAME
while [[ ${#GPG_USER_NAME} -lt 5 ]]; do
{
echo -e "\nEnter your Real Name (At least 5 characters long):"
read -r GPG_USER_NAME
};done
echo -e "\nEnter your email@adress.org:"
read -r GPG_USER_MAIL
while ! $(expr "$GPG_USER_MAIL" : '.*@' >/dev/null); do
{
echo -e "\nEnter your email@address.org:"
read -r GPG_USER_MAIL
};done
echo -e "\nEnter Comment (Optional, to distinguish this key from others with same previous attributes. Must be smaller then 60 characters):"
read -r GPG_USER_MAIL
while [[ ${#gpgcard_comment} -gt 60 ]]; do
{
echo -e "\nEnter Comment (Optional, to distinguish this key from others with same previous attributes. Must be smaller then 60 characters):"
read -r GPG_USER_MAIL
};done
fi
## sanity check the USB, GPG key, and boot device before proceeding further
# mount USB, then remount rw
echo -e "\nChecking for USB media...\n"
# ensure /media not mounted
umount /media 2>/dev/null
# mount-usb will detect and prompt if no USB inserted
if ! mount-usb rw 2>/tmp/error; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Unable to mount USB on /media:\n\n${ERROR}"
fi
# ensure GPG key connected
echo -e "\nChecking for GPG Key...\n"
# USB kernel modules already loaded via mount-usb
if ! gpg --card-status >/dev/null 2>&1 ; then
whiptail_error "Can't access GPG Key; remove and reinsert, then press Enter to retry."
if ! gpg --card-status >/dev/null 2>/tmp/error ; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Unable to detect GPG Key:\n\n${ERROR}"
fi
fi
# detect and set /boot device
echo -e "\nDetecting and setting boot device...\n"
if ! detect_boot_device ; then
whiptail_error_die "Unable to locate /boot files on any mounted disk"
else
echo -e "Boot device set to $CONFIG_BOOT_DEV\n"
fi
# update configs
replace_config /etc/config.user "CONFIG_BOOT_DEV" "$CONFIG_BOOT_DEV"
combine_configs
## reset TPM and set default password
if [ "$CONFIG_TPM" = "y" ]; then
echo -e "\nResetting TPM...\n"
{
echo $TPM_PASS_DEF
echo $TPM_PASS_DEF
} | /bin/tpm-reset >/dev/null 2>/tmp/error
if [ $? -ne 0 ]; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Error resetting TPM:\n\n${ERROR}"
fi
fi
# clear local keyring
rm /.gnupg/*.gpg 2>/dev/null
rm /.gnupg/*.kbx 2>/dev/null
gpg --list-keys >/dev/null 2>&1
## reset the GPG Key
echo -e "\nResetting GPG Key...\n(this will take a minute or two)\n"
gpg_key_reset
# parse name of generated key
GPG_GEN_KEY=`grep -A1 pub /tmp/gpg_card_edit_output | tail -n1 | sed -nr 's/^([ ])*//p'`
PUBKEY="/tmp/${GPG_GEN_KEY}.asc"
if [ "$CUSTOM_PASS" != "" ]; then
echo -e "\nChanging default GPG Admin PIN\n"
gpg_key_change_pin "3" "$ADMIN_PIN_DEF" "$CUSTOM_PASS"
echo -e "\nChanging default GPG User PIN\n"
gpg_key_change_pin "1" "$USER_PIN_DEF" "$CUSTOM_PASS"
USER_PIN_DEF=$CUSTOM_PASS
ADMIN_PIN_DEF=$CUSTOM_PASS
fi
## export generated key to USB
echo -e "\nExporting generated key to USB...\n"
# export pubkey to file
if ! gpg --export --armor $GPG_GEN_KEY > "${PUBKEY}" 2>/tmp/error ; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "GPG Key gpg export to file failed!\n\n$ERROR"
fi
# copy to USB
if ! cp "${PUBKEY}" "/media/${GPG_GEN_KEY}.asc" 2>/tmp/error ; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Key export error: unable to copy ${GPG_GEN_KEY}.asc to /media:\n\n$ERROR"
fi
umount /media 2>/dev/null
## flash generated key to ROM
echo -e "\nReading current firmware...\n(this will take a minute or two)\n"
/bin/flash.sh -r /tmp/oem-setup.rom >/dev/null 2>/tmp/error
if [ ! -s /tmp/oem-setup.rom ]; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Error reading current firmware:\n\n$ERROR"
fi
# ensure key imported locally
if ! cat "$PUBKEY" | gpg --import >/dev/null 2>/tmp/error ; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Error importing GPG key:\n\n$ERROR"
fi
# update /.gnupg/trustdb.gpg to ultimately trust all user provided public keys
if ! gpg --list-keys --fingerprint --with-colons 2>/dev/null \
| sed -E -n -e 's/^fpr:::::::::([0-9A-F]+):$/\1:6:/p' \
| gpg --import-ownertrust >/dev/null 2>/tmp/error ; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Error importing GPG ownertrust:\n\n$ERROR"
fi
if ! gpg --update-trust >/dev/null 2>/tmp/error ; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Error updating GPG ownertrust:\n\n$ERROR"
fi
# clear any existing heads/gpg files from current firmware
for i in `cbfs -o /tmp/oem-setup.rom -l | grep -e "heads/"`; do
cbfs -o /tmp/oem-setup.rom -d $i
done
# add heads/gpg files to current firmware
if [ -e /.gnupg/pubring.kbx ];then
cbfs -o /tmp/oem-setup.rom -a "heads/initrd/.gnupg/pubring.kbx" -f /.gnupg/pubring.kbx
if [ -e /.gnupg/pubring.gpg ];then
rm /.gnupg/pubring.gpg
fi
elif [ -e /.gnupg/pubring.gpg ];then
cbfs -o /tmp/oem-setup.rom -a "heads/initrd/.gnupg/pubring.gpg" -f /.gnupg/pubring.gpg
fi
if [ -e /.gnupg/trustdb.gpg ]; then
cbfs -o /tmp/oem-setup.rom -a "heads/initrd/.gnupg/trustdb.gpg" -f /.gnupg/trustdb.gpg
fi
# persist user config changes (boot device)
if [ -e /etc/config.user ]; then
cbfs -o /tmp/oem-setup.rom -a "heads/initrd/etc/config.user" -f /etc/config.user
fi
# flash updated firmware image
echo -e "\nAdding generated key to current firmware and re-flashing...\n"
if ! /bin/flash.sh /tmp/oem-setup.rom >/dev/null 2>/tmp/error ; then
ERROR=$(tail -n 1 /tmp/error)
whiptail_error_die "Error flashing updated firmware image:\n\n$ERROR"
fi
## sign files in /boot and generate checksums
echo -e "\nSigning boot files and generating checksums...\n"
generate_checksums
## all done -- reboot
whiptail --msgbox "
The OEM Factory Reset has completed successfully\n\n
After rebooting, you will need to generate new TOTP/HOTP secrets\n
when prompted in order to complete the setup process.\n\n
Press Enter to reboot.\n" \
$WIDTH $HEIGHT --title "OEM Factory Reset Complete"
reboot