functions

#!/bin/sh
# Shell functions for most initialization scripts

die() {
	echo >&2 "$*";
	exit 1;
}

warn() {
	echo >&2 "$*";
}

recovery() {
	echo >&2 "!!!!! $*"

	# Remove any temporary secret files that might be hanging around
	# but recreate the directory so that new tools can use it.
	rm -rf /tmp/secret
	mkdir -p /tmp/secret
	if [ "$CONFIG_TPM" = y ]; then
		tpm extend -ix 4 -ic recovery
	fi
	echo >&2 "!!!!! Starting recovery shell"
	sleep 1

	if [ -x /bin/setsid ]; then
		exec /bin/setsid -c /bin/ash
	else
		exec /bin/ash
	fi
}

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
}

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

	gpg --card-status \
	|| die "gpg card read failed"
}


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 -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.$$ \
			|| die "Failed to read cbfs file from ROM"
			cbfs -o $1 -a $old_file -f /tmp/rom.$$ \
			|| die "Failed to write cbfs file to new ROM file"
		fi
	done
}