Mount BitLocker drive with DisLocker

dislocker.sh

#!/bin/bash

HARDDRIVE=/dev/sdb2
BITLOCK_MOUNT=/media/bitlocker
DECRYPTED_MOUNT=/media/mount
USAGE="Usage: dislock [options]

Options:
    -k, --recoverykey KEY  The BitLocker recovery key to use for mounting
    -u, --umount           Unmount the mounted BitLocker volume
"

# run this script as root.
if [ "$(id -u)" != "0" ]; then
	echo "This script must be run as root" 1>&2
	exit 1
fi

if [ "$1" == "-k" ] || [ "$1" == "--recoverykey" ]; then
	if [ -n "$2" ]; then
		RECOVERYKEY="$2"
		if [ "$(ls -A $BITLOCK_MOUNT)" ]; then
			echo "The directory $BITLOCK_MOUNT is not empty. Maybe the BitLocker volume is already mounted?"
			exit 1
		else
			mkdir -p "$BITLOCK_MOUNT" "$DECRYPTED_MOUNT"
			dislocker -v -V "$HARDDRIVE" -p"$RECOVERYKEY" -- "$BITLOCK_MOUNT"
			mount -o loop,ro $BITLOCK_MOUNT/dislocker-file "$DECRYPTED_MOUNT"
			echo "BitLocker is now mounted at $DECRYPTED_MOUNT."
			exit 0
		fi
	else
		printf "Option '%s' requires an argument.\n$USAGE" "$1"
		exit 1
	fi
elif [ "$1" == "-u" ] || [ "$1" == "--umount" ]; then
	if [ "$(ls -A $DECRYPTED_MOUNT)" ]; then
		umount "$DECRYPTED_MOUNT"
		umount "$BITLOCK_MOUNT"
		echo "BitLocker is now unmounted."
		exit 0
	else
		echo "The directory $BITLOCK_MOUNT is empty. Maybe the BitLocker volume is not mounted?"
		exit 1
	fi
elif [ -z "$1" ]; then
	echo "$USAGE"
else
	printf "dislock: invalid option '%s'.\n$USAGE" "$1"
	exit 1
fi