#!/usr/bin/bash

umask 022

usage=0
enable_fips=
check=0
boot_config=1
err_if_disabled=0
output_text=1

is_ostree_system=0
if test -f /run/ostree-booted; then
    is_ostree_system=1
fi

enable2txt () {
	case "$1" in
		0)
			echo "disabled"
			;;
		1)
			echo "enabled"
			;;
	esac
}

cond_echo () {
	if test "$output_text" != 0;then
		echo "$@"
	fi
}

while test $# -ge 1 ; do
	case "$1" in
		--enable)
			enable_fips=1
			;;
		--disable)
			enable_fips=0
			;;
		--check)
			check=1
			enable_fips=2
			;;
		--is-enabled)
			check=1
			enable_fips=2
			err_if_disabled=1
			output_text=0
			;;
		--no-bootcfg)
			boot_config=0
			;;
		*)
			usage=1
			;;
	esac
	shift
done

if test $usage = 1 -o x$enable_fips = x ; then
	echo "Check, enable, or disable the system FIPS mode."
	echo "usage: $0 --enable|--disable [--no-bootcfg]"
	echo "usage: $0 --check"
	echo "usage: $0 --is-enabled"
	exit 2
fi

# We don't handle the boot config on OSTree systems for now; it is assumed to be
# handled at a higher level. E.g. in Fedora CoreOS and RHEL CoreOS, it is
# intrinsically tied to the firstboot procedure.
if test "$is_ostree_system" = 1 && test "$enable_fips" = 1 && test "$boot_config" = 1; then
    cond_echo "Cannot perform boot config changes on OSTree systems (use --no-bootcfg)"
    exit 1
fi


if [ "$(id -u)" != 0 ]; then
	echo "You must be root to run $(basename $0)"
	exit 1
fi


# Detect 1: kernel FIPS flag
fips_kernel_enabled=$(cat /proc/sys/crypto/fips_enabled)

# Detect 2: initramfs fips module presence; not always can be done
initramfs_fips_module=0
initramfs_inspectable=0
if test -d /boot -a -x /usr/bin/lsinitrd; then
	initramfs_inspectable=1
	if lsinitrd -m 2>/dev/null | grep -Fxq fips; then
		initramfs_fips_module=1
	fi
fi

# Detect 3: crypto-policy base policy
current_policy="$(cat /etc/crypto-policies/state/current)"
base_policy="$(echo $current_policy| cut -f 1 -d :)"
if test "$base_policy" == "FIPS" ; then
	base_policy_is_fips=1
else
	base_policy_is_fips=0
fi


if test $check = 1 ; then
	# Look for signs for both enabling and disabling FIPS mode
	fips_positive=0
	fips_negative=0

	# Display 1: kernel FIPS flag
	cond_echo "FIPS mode is $(enable2txt $fips_kernel_enabled)."

	# Display 2: initramfs fips module
	if test "$initramfs_inspectable" = 1 ; then
		cond_echo -n "Initramfs fips module is "
		cond_echo "$(enable2txt $initramfs_fips_module)."
	fi

	# Display 3: active crypto-policy
	cond_echo -n "The current crypto policy ($current_policy) "
	if test "$base_policy_is_fips" == 1 ; then
		cond_echo 'is based on the FIPS policy.'
	else
		cond_echo -n 'neither is the FIPS policy '
		cond_echo 'nor is based on the FIPS policy.'
	fi

	# Decide 1: kernel FIPS flag
	if test "$fips_kernel_enabled" = 1 ; then
		fips_positive=1
	else
		fips_negative=1
	fi

	# Decide 2: initramfs module presence
	if test "$initramfs_inspectable" = 1 ; then
		if test "$initramfs_fips_module" = 1 ; then
			fips_positive=1
		else
			fips_negative=1
		fi
	fi

	# Decide 3: active crypto-policy
	if test "$base_policy_is_fips" = 1 ; then
		fips_positive=1
	else
		fips_negative=1
	fi

	# Make the FIPS mode consistency decision
	if test "$fips_positive" = 1 -a "$fips_negative" = 1 ; then
		cond_echo 'Inconsistent state detected.'
		exit 1
	fi

	# Error out if `--is-enabled` was passed and FIPS mode is not enabled
	if test "$fips_positive" = 0 -a "$err_if_disabled" = 1 ; then
		cond_echo 'FIPS mode is not enabled.'
		exit 2
	fi

	exit 0
fi


if test $enable_fips = 1 ; then
	if test "$initramfs_fips_module" = 0 ; then
		fips-finish-install --complete
		if test $? != 0 ; then
			echo "Installation of FIPS modules could not be completed."
			exit 1
		fi
	fi
	if test "$base_policy_is_fips" == 1 ; then
		cond_echo -n 'Preserving current FIPS-based policy '
		cond_echo "${current_policy}."
		cond_echo -n 'Please review the subpolicies to ensure they '
		cond_echo 'only restrict, not relax the FIPS policy.'
	else
		target=FIPS
	fi
	update-crypto-policies --no-reload --set "${target}" 2>/dev/null
else
	update-crypto-policies --no-reload --set DEFAULT 2>/dev/null
fi

boot_device="$(df -P /boot | tail -1)"
echo "$boot_device" | grep -q ' /$' && boot_device='/' || boot_device=$(echo "$boot_device" | cut -d ' ' -f 1)

if test x"$boot_device" = x ; then
	echo "Boot device not identified, you have to configure the bootloader manually."
	boot_device_opt=" boot=UUID=<your-boot-device-uuid>"
	boot_config=0
else
        if test "$boot_device" = / ; then
            boot_device_opt=""
        else
            boot_device_opt=" boot=UUID=$(blkid -s UUID -o value $boot_device)"
        fi
fi

if test "$boot_config" = 1 && test ! -x "$(command -v grubby)" ; then
	echo "The grubby command is missing, please configure the bootloader manually."
	boot_config=0
fi

echo "FIPS mode will be $(enable2txt $enable_fips)."

fipsopts="fips=$enable_fips$boot_device_opt"

if test $boot_config = 0 ; then
	echo "Now you need to configure the bootloader to add kernel options \"$fipsopts\""
	echo "and reboot the system for the setting to take effect."
else
	grubby --update-kernel=ALL --args="$fipsopts"
	if test x"$(uname -m)" = xs390x; then
		if command -v zipl >/dev/null; then
			zipl
		else
			echo -n '`zipl` execution has been skipped: '
			echo '`zipl` not found.'
		fi
	fi
	echo "Please reboot the system for the setting to take effect."
fi

exit 0