#!/bin/sh

# truecrypt.sh - A wrapper for the *NIX port of Truecrypt
#	(http://www.truecrypt.org/) to make it simpler to use as an
#	unprivileged user.
#
#	Specifically, I wrote this script to scratch a personal itch, which
#	involved (un)mounting Truecrypt datastores kept on USB keys used on a
#	number of different systems.
#
#	This script assumes that sudo is installed, and that the user you'll be
#	accessing the volume through has limited access to mount and unmount
#	Truecrypt volumes.  To do this, the following line must be placed in the
#	/etc/sudoers file:
#		%truecrypt ALL=(root) NOPASSWD:/usr/bin/truecrypt

# Revision: v1.0.  Initial release.

# Variables
# Determine the UID and GID to pass to the truecrypt utility.
MOUNT_UID=`id | awk '{print $1}' | sed 's/uid=[0-9]*(//' | sed 's/)//'`
MOUNT_GID=`id | awk '{print $2}' | sed 's/gid=[0-9]*(//' | sed 's/)//'`

# Here's where the heavy lifting happens - this parses the arguments passed to
# script and executes the truecrypt binary with the appropriate arguments.
case "$1" in
	'mount')
		sudo truecrypt -M uid=$MOUNT_UID,gid=$MOUNT_GID $2 $3
		exit 0
		;;
	'unmount')
		UNMOUNT_DIR=`echo $2 | sed 's/\/$//'`
		sudo truecrypt -d $UNMOUNT_DIR
		exit 0
		;;
	'status')
		mount | grep 'mapper'
		exit 0
		;;
	*)
		echo "USAGE:"
		echo "	Mounting: $0 mount /path/to/datastore /mntpoint"
		echo "	Unmounting: $0 unmount /mntpoint"
		echo "	Status: $0 status"
		echo
		exit 1
	esac
exit 0
# End of script.