#!/bin/bash
# mountc
# 
# Mount luks-encrypted filesystems
# 
# USAGE: mountc <partition> <mountpoint> [luks.key]
# EXAMPLE: mountc sdf1 mydrive
#
#	Copyright © 2021 Keith Irwin (www.ki9.us)
#	
#	This program is free software: you can redistribute it and/or modify
#	it under the terms of the GNU General Public License as published by
#	the Free Software Foundation, either version 3 of the License, or
#	(at your option) any later version.
#	
#	This program is distributed in the hope that it will be useful,
#	but WITHOUT ANY WARRANTY; without even the implied warranty of
#	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#	GNU General Public License for more details.
#	
#	You should have received a copy of the GNU General Public License
#	along with this program.  If not, see <http://www.gnu.org/licenses/>.


# Check for root
if [[ $EUID -ne 0 ]]; then
	echo "This script must be run as root" 
	exit 1
fi

# Get args
me="$(basename $0)"
if [[ $# -eq 3 ]]; then
	part="$1"
	mp="$2"
	kf="$3"
elif [[ $# -eq 2 ]]; then
	device="$1"
	name="$2"
	kf=""
else
	echo "USAGE: $me <partition> <mountpoint> [keyfile]"
	exit 2
fi
name="$(basename $mp)"

# Quit if given "no" at prompt
bail(){ [[ "$0" = "$BASH_SOURCE" ]] && exit 1 || return 1; }


## RUNTIME ##

# Where keys are stored
KEYDIR="/root/luks"

# Initial output
echo "  mountc	Copyright © 2021 Keith Irwin (www.ki9.us)"
echo "  This program comes with ABSOLUTELY NO WARRANTY; for details"
echo "  see the LICENSE.md that came with it"
echo "  This is free software, and you are welcome to redistribute it"
echo "  under certain conditions"
echo

# Check that mountpoint is directory
if [ ! -d "$mp" ]; then
	echo "$mp is not a directory"
	exit 2
fi
# TODO: Check that mountpoint is not already mounted
# TODO: Check that mountpoint is empty

# Check if already decrypted
if [ -h "/dev/mapper/$name" ]; then
	echo "/dev/mapper/$name already exists.  Attempting to mount it..."
else
	
	# Decrypt
	if [ -f "$kf" ]; then
		echo "Decrypting /dev/$part with $kf..."
		cryptsetup luksOpen "/dev/$part" "$name" --key-file="$kf"
	else
		echo "Decrypting /dev/$part with password..."
		cryptsetup luksOpen "/dev/$part" "$name"
	fi

fi

# Mount decrypted filesystem
echo "Mounting /dev/mapper/$name filesystem to $mp..."
chmod 755 "$mp"
mount "/dev/mapper/$name" "$mp" && \
echo "DONE!"