heads/initrd/etc/functions
3hhh d07df1e60b
initrd: escape_zero: allow some more characters
Since it's not supposed to be shell safe, just display safe
inside double quotes, we can allow some more characters.

Also fix the escape character not being escaped.
2023-01-14 13:14:09 +01:00

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#!/bin/sh
# Shell functions for most initialization scripts
die() {
echo >&2 "$*";
sleep 2;
exit 1;
}
warn() {
echo >&2 "$*";
sleep 1;
}
recovery() {
echo >&2 "!!!!! $*"
# Remove any temporary secret files that might be hanging around
# but recreate the directory so that new tools can use it.
#safe to always be true. Otherwise "set -e" would make it exit here
shred -n 10 -z -u /tmp/secret/* 2> /dev/null || true
rm -rf /tmp/secret
mkdir -p /tmp/secret
# ensure /tmp/config exists for recovery scripts that depend on it
touch /tmp/config
if [ "$CONFIG_TPM" = y ]; then
tpm extend -ix 4 -ic recovery
fi
while [ true ]
do
echo >&2 "!!!!! Starting recovery shell"
sleep 1
if [ -x /bin/setsid ]; then
/bin/setsid -c /bin/ash
else
/bin/ash
fi
done
}
pause_recovery() {
read -p 'Hit enter to proceed to recovery shell:'
recovery $*
}
pcrs() {
head -8 /sys/class/tpm/tpm0/pcrs
}
confirm_totp()
{
prompt="$1"
last_half=X
unset totp_confirm
while true; do
# update the TOTP code every thirty seconds
date=`date "+%Y-%m-%d %H:%M:%S"`
seconds=`date "+%s"`
half=`expr \( $seconds % 60 \) / 30`
if [ "$CONFIG_TPM" != y ]; then
TOTP="NO TPM"
elif [ "$half" != "$last_half" ]; then
last_half=$half;
TOTP=`unseal-totp` \
|| recovery "TOTP code generation failed"
fi
echo -n "$date $TOTP: "
# read the first character, non-blocking
read \
-t 1 \
-n 1 \
-s \
-p "$prompt" \
totp_confirm \
&& break
# nothing typed, redraw the line
echo -ne '\r'
done
# clean up with a newline
echo
}
enable_usb()
{
if [ "$CONFIG_LINUX_USB_COMPANION_CONTROLLER" = y ]; then
if ! lsmod | grep -q uhci_hcd; then
insmod /lib/modules/uhci-hcd.ko \
|| die "uhci_hcd: module load failed"
fi
if ! lsmod | grep -q ohci_hcd; then
insmod /lib/modules/ohci-hcd.ko \
|| die "ohci_hcd: module load failed"
fi
if ! lsmod | grep -q ohci_pci; then
insmod /lib/modules/ohci-pci.ko \
|| die "ohci_pci: module load failed"
fi
fi
if ! lsmod | grep -q ehci_hcd; then
insmod /lib/modules/ehci-hcd.ko \
|| die "ehci_hcd: module load failed"
fi
if ! lsmod | grep -q ehci_pci; then
insmod /lib/modules/ehci-pci.ko \
|| die "ehci_pci: module load failed"
fi
if ! lsmod | grep -q xhci_hcd; then
insmod /lib/modules/xhci-hcd.ko \
|| die "xhci_hcd: module load failed"
fi
if ! lsmod | grep -q xhci_pci; then
insmod /lib/modules/xhci-pci.ko \
|| die "xhci_pci: module load failed"
sleep 2
fi
if [ "$CONFIG_USB_KEYBOARD" = y ]; then
if ! lsmod | grep -q usbhid; then
insmod /lib/modules/usbhid.ko \
|| die "usbhid: module load failed"
fi
fi
}
list_usb_storage()
{
stat -c %N /sys/block/sd* 2>/dev/null | grep usb |
cut -f1 -d ' ' |
sed "s/[']//g" |
while read b; do
# Ignore devices of size 0, such as empty SD card
# readers on laptops attached via USB.
if [ "$(cat "$b/size")" -gt 0 ]; then
echo "$b"
fi
done |
sed "s|/sys/block|/dev|" |
while read b; do
# If the device has a partition table, ignore it and
# include the partitions instead - even if the kernel
# hasn't detected the partitions yet. Such a device is
# never usable directly, and this allows the "wait for
# disks" loop in mount-usb to correctly wait for the
# partitions.
if fdisk -l "$b" | grep -q "doesn't contain a valid partition table"; then
# No partition table, include this device
echo "$b"
else
# Has a partition table, include partitions
ls -1 "$b"* | awk 'NR!=1 {print $0}'
fi
done
}
confirm_gpg_card()
{
read \
-n 1 \
-p "Please confirm that your GPG card is inserted [Y/n]: " \
card_confirm
echo
if [ "$card_confirm" != "y" \
-a "$card_confirm" != "Y" \
-a -n "$card_confirm" ] \
; then
die "gpg card not confirmed"
fi
# setup the USB so we can reach the GPG card
enable_usb
echo -e "\nVerifying presence of GPG card...\n"
# ensure we don't exit without retrying
errexit=$(set -o | grep errexit | awk '{print $2}')
set +e
gpg --card-status > /dev/null
if [ $? -ne 0 ]; then
# prompt for reinsertion and try a second time
read -n1 -r -p \
"Can't access GPG key; remove and reinsert, then press Enter to retry. " \
ignored
# restore prev errexit state
if [ "$errexit" = "on" ]; then
set -e
fi
# retry card status
gpg --card-status > /dev/null \
|| die "gpg card read failed"
fi
# restore prev errexit state
if [ "$errexit" = "on" ]; then
set -e
fi
}
check_tpm_counter()
{
LABEL=${2:-3135106223}
# if the /boot.hashes file already exists, read the TPM counter ID
# from it.
if [ -r "$1" ]; then
TPM_COUNTER=`grep counter- "$1" | cut -d- -f2`
else
warn "$1 does not exist; creating new TPM counter"
read -s -p "TPM Owner password: " tpm_password
echo
tpm counter_create \
-pwdo "$tpm_password" \
-pwdc '' \
-la $LABEL \
| tee /tmp/counter \
|| die "Unable to create TPM counter"
TPM_COUNTER=`cut -d: -f1 < /tmp/counter`
fi
if [ -z "$TPM_COUNTER" ]; then
die "$1: TPM Counter not found?"
fi
}
read_tpm_counter()
{
tpm counter_read -ix "$1" | tee "/tmp/counter-$1" \
|| die "Counter read failed"
}
increment_tpm_counter()
{
tpm counter_increment -ix "$1" -pwdc '' \
| tee /tmp/counter-$1 \
|| die "Counter increment failed"
}
check_config() {
if [ ! -d /tmp/kexec ]; then
mkdir /tmp/kexec \
|| die 'Failed to make kexec tmp dir'
else
rm -rf /tmp/kexec/* \
|| die 'Failed to empty kexec tmp dir'
fi
if [ ! -r $1/kexec.sig ]; then
return
fi
if [ `find $1/kexec*.txt | wc -l` -eq 0 ]; then
return
fi
if [ "$2" != "force" ]; then
if ! sha256sum `find $1/kexec*.txt` | gpgv $1/kexec.sig - ; then
die 'Invalid signature on kexec boot params'
fi
fi
echo "+++ Found verified kexec boot params"
cp $1/kexec*.txt /tmp/kexec \
|| die "Failed to copy kexec boot params to tmp"
}
preserve_rom() {
new_rom="$1"
old_files=`cbfs -t 50 -l 2>/dev/null | grep "^heads/"`
for old_file in `echo $old_files`; do
new_file=`cbfs.sh -o $1 -l | grep -x $old_file`
if [ -z "$new_file" ]; then
echo "+++ Adding $old_file to $1"
cbfs -t 50 -r $old_file >/tmp/rom.$$ \
|| die "Failed to read cbfs file from ROM"
cbfs.sh -o $1 -a $old_file -f /tmp/rom.$$ \
|| die "Failed to write cbfs file to new ROM file"
fi
done
}
replace_config() {
CONFIG_FILE=$1
CONFIG_OPTION=$2
NEW_SETTING=$3
touch $CONFIG_FILE
# first pull out the existing option from the global config and place in a tmp file
awk "gsub(\"^export ${CONFIG_OPTION}=.*\",\"export ${CONFIG_OPTION}=\\\"${NEW_SETTING}\\\"\")" /tmp/config > ${CONFIG_FILE}.tmp
awk "gsub(\"^${CONFIG_OPTION}=.*\",\"${CONFIG_OPTION}=\\\"${NEW_SETTING}\\\"\")" /tmp/config >> ${CONFIG_FILE}.tmp
# then copy any remaining settings from the existing config file, minus the option you changed
grep -v "^export ${CONFIG_OPTION}=" ${CONFIG_FILE} | grep -v "^${CONFIG_OPTION}=" >> ${CONFIG_FILE}.tmp || true
sort ${CONFIG_FILE}.tmp | uniq > ${CONFIG_FILE}
rm -f ${CONFIG_FILE}.tmp
}
combine_configs() {
cat /etc/config* > /tmp/config
}
update_checksums()
{
# ensure /boot mounted
if ! grep -q /boot /proc/mounts ; then
mount -o ro /boot \
|| recovery "Unable to mount /boot"
fi
# remount RW
mount -o rw,remount /boot
# sign and auto-roll config counter
extparam=
if [ "$CONFIG_TPM" = "y" ]; then
extparam=-r
fi
if ! kexec-sign-config -p /boot -u $extparam ; then
rv=1
else
rv=0
fi
# switch back to ro mode
mount -o ro,remount /boot
return $rv
}
print_tree() {
find ./ ! -path './kexec*' -print0 | sort -z
}
# Escape zero-delimited standard input to safely display it to the user in e.g.
# `whiptail`, `less`, `echo`, `cat`. Doesn't produce shell-escaped output.
# Most printable characters are passed verbatim (exception: \).
# These escapes are used to replace their corresponding characters: #n#r#t#v#b
# Other characters are rendered as hexadecimal escapes.
# escape_zero [prefix] [escape character]
# prefix: \0 in the input will result in \n[prefix]
# escape character: character to use for escapes (default: #); \ may be interpreted by `whiptail`
escape_zero() {
local prefix="$1"
local echar="${2:-#}"
local todo=""
local echar_hex="$(echo -n "$echar" | xxd -p -c1)"
[ ${#echar_hex} -eq 2 ] || die "Invalid escape character $echar passed to escape_zero(). Programming error?!"
echo -e -n "$prefix"
xxd -p -c1 | tr -d '\n' |
{
while IFS= read -r -n2 -d '' ; do
if [ -n "$todo" ] ; then
#REPLY == " " is EOF
[[ "$REPLY" == " " ]] && echo '' || echo -e -n "$todo"
todo=""
fi
case "$REPLY" in
00)
todo="\n$prefix"
;;
08)
echo -n "${echar}b"
;;
09)
echo -n "${echar}t"
;;
0a)
echo -n "${echar}n"
;;
0b)
echo -n "${echar}v"
;;
0d)
echo -n "${echar}r"
;;
"$echar_hex")
echo -n "$echar$echar"
;;
#interpreted characters:
2[0-9a-f]|3[0-9a-f]|4[0-9a-f]|5[0-9abd-f]|6[0-9a-f]|7[0-9a-e])
echo -e -n '\x'"$REPLY"
;;
# All others are escaped
*)
echo -n "${echar}x$REPLY"
;;
esac
done
}
}
# Currently heads doesn't support signing file names with certain characters
# due to https://bugs.busybox.net/show_bug.cgi?id=14226. Also, certain characters
# may be intepreted by `whiptail`, `less` et al (e.g. \n, \b, ...).
assert_signable() {
# ensure /boot mounted
if ! grep -q /boot /proc/mounts ; then
mount -o ro /boot || die "Unable to mount /boot"
fi
find /boot -print0 > /tmp/signable.ref
local del='\001-\037\134\177-\377'
LC_ALL=C tr -d "$del" < /tmp/signable.ref > /tmp/signable.del || die "Failed to execute tr."
if ! cmp -s "/tmp/signable.ref" "/tmp/signable.del" &> /dev/null ; then
local user_out="/tmp/hash_output_mismatches"
local add="Please investigate!"
[ -f "$user_out" ] && add="Please investigate the following relative paths to /boot (where # are sanitized invalid characters):"$'\n'"$(cat "$user_out")"
recovery "Some /boot file names contain characters that are currently not supported by heads: $del"$'\n'"$add"
fi
rm -f /tmp/signable.*
}
verify_checksums()
{
local boot_dir="$1"
local gui="${2:-y}"
(
set +e -o pipefail
local ret=0
cd "$boot_dir" || ret=1
sha256sum -c "$TMP_HASH_FILE" > /tmp/hash_output || ret=1
# also make sure that the file & directory structure didn't change
# (sha256sum won't detect added files)
print_tree > /tmp/tree_output || ret=1
if ! cmp -s "$TMP_TREE_FILE" /tmp/tree_output &> /dev/null ; then
ret=1
[[ "$gui" != "y" ]] && exit "$ret"
# produce a diff that can safely be presented to the user
# this is relatively hard as file names may e.g. contain backslashes etc.,
# which are interpreted by whiptail, less, ...
escape_zero "(new) " < "$TMP_TREE_FILE" > "${TMP_TREE_FILE}.user"
escape_zero "(new) " < /tmp/tree_output > /tmp/tree_output.user
diff "${TMP_TREE_FILE}.user" /tmp/tree_output.user | grep -E '^\+\(new\).*$' | sed -r 's/^\+\(new\)/(new)/g' >> /tmp/hash_output
rm -f "${TMP_TREE_FILE}.user"
rm -f /tmp/tree_output.user
fi
exit $ret
)
return $?
}
# detect and set /boot device
# mount /boot if successful
detect_boot_device()
{
# unmount /boot to be safe
cd / && umount /boot 2>/dev/null
# check $CONFIG_BOOT_DEV if set/valid
if [ -e "$CONFIG_BOOT_DEV" ]; then
if mount -o ro $CONFIG_BOOT_DEV /boot >/dev/null 2>&1; then
if ls -d /boot/grub* >/dev/null 2>&1; then
# CONFIG_BOOT_DEV is valid device and contains an installed OS
return 0
fi
fi
fi
# generate list of possible boot devices
fdisk -l | grep "Disk /dev/" | cut -f2 -d " " | cut -f1 -d ":" > /tmp/disklist
# filter out extraneous options
> /tmp/boot_device_list
for i in `cat /tmp/disklist`; do
# remove block device from list if numeric partitions exist, since not bootable
DEV_NUM_PARTITIONS=$((`ls -1 $i* | wc -l`-1))
if [ ${DEV_NUM_PARTITIONS} -eq 0 ]; then
echo $i >> /tmp/boot_device_list
else
ls $i* | tail -${DEV_NUM_PARTITIONS} >> /tmp/boot_device_list
fi
done
# iterate thru possible options and check for grub dir
for i in `cat /tmp/boot_device_list`; do
umount /boot 2>/dev/null
if mount -o ro $i /boot >/dev/null 2>&1; then
if ls -d /boot/grub* >/dev/null 2>&1; then
CONFIG_BOOT_DEV="$i"
return 0
fi
fi
done
# no valid boot device found
echo "Unable to locate /boot files on any mounted disk"
umount /boot 2>/dev/null
return 1
}
calc()
{
awk "BEGIN { print "$*" }";
}
print_battery_health()
{
if [ -d /sys/class/power_supply/BAT* ]; then
battery_health=$(calc $(cat /sys/class/power_supply/BAT*/charge_full)/$(cat /sys/class/power_supply/BAT*/charge_full_design)*100 | awk -F "." {'print $1'})
echo "$battery_health"
fi
}
print_battery_charge()
{
if [ -d /sys/class/power_supply/BAT* ]; then
battery_charge=$(calc $(cat /sys/class/power_supply/BAT*/charge_now)/$(cat /sys/class/power_supply/BAT*/charge_full)*100 | awk -F "." {'print $1'})
echo "$battery_charge"
fi
}
generate_random_mac_address()
{
#Borrowed from https://stackoverflow.com/questions/42660218/bash-generate-random-mac-address-unicast
hexdump -n 6 -ve '1/1 "%.2x "' /dev/urandom | awk -v a="2,6,a,e" -v r="$RANDOM" 'BEGIN{srand(r);}NR==1{split(a,b,",");r=int(rand()*4+1);printf "%s%s:%s:%s:%s:%s:%s\n",substr($1,0,1),b[r],$2,$3,$4,$5,$6}'
}