#!/bin/bash
# luksit
# 
# USAGE: luksit <device> <name> [filesystem]
# EXAMPLE: luksit sdf mydrive ext4
#
#	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
if [[ $# -eq 3 ]]; then
	device="$1"
	name="$2"
	fs="$3"
elif [[ $# -eq 2 ]]; then
	device="$1"
	name="$2"
	fs="ext3"
else
	echo "USAGE: $0 <device> <name> [filesystem]"
	exit 2
fi

# 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 "  luksit  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 if name is used
#if [ -h "/dev/mapper/$name" ]; then
#	echo "/dev/mapper/$name already exists."
#	exit 420
#fi

# Wipe disk
read -p "Wipe /dev/$device with zeroes first? [y/n]" -n 1 -r
echo; [[ $REPLY =~ ^[Yy]$ ]] && \
( echo "Wiping disk with zeros..." ; \
dd if=/dev/zero bs=1M | pv | dd of="/dev/$device" bs=1M )

# Set up partition
echo "Setting up partition..."
umount "/dev/$device" >/dev/null
parted "/dev/$device" mklabel gpt && \
parted --script -- "/dev/$device" mkpart primary 1 -1 && \
# Get first partition name
part="$(lsblk --list --noheadings --output name "/dev/$device" | sed -n '2 p')"

# Generate key file
mkdir "$KEYDIR/" >/dev/null
if [ -f "$KEYDIR/$name.key" ]; then
	echo ""
else
	echo -n "Generating key file... "
	dd if=/dev/urandom of="$KEYDIR/$name.key" bs=1024 count=4 && \
	chmod 0400 "$KEYDIR/$name.key" && echo "Done."
fi

# Encrypt
echo "Creating luks encrypted partition..."
cryptsetup luksFormat "/dev/$part" "$KEYDIR/$name.key" && \
cryptsetup luksAddKey "/dev/$part" "$KEYDIR/$name.key" --key-file="$KEYDIR/$name.key" && \

# Mount new luks partition
echo "Mounting luks partition..."
cryptsetup luksOpen "/dev/$part" "$name" --key-file="$KEYDIR/$name.key" && \

# Write filesystem on new luks partition
echo "Creating $fs filesystem in luks partition..."
cryptsetup resize "$name" --key-file="$KEYDIR/$name.key"&& \
"mkfs.$fs" "/dev/mapper/$name" -L "$name" && \

# 
echo "Mounting $fs filesystem to /mnt/$name..."
mkdir "/mnt/$name" >/dev/null
chmod 755 "/mnt/$name"
mount "/dev/mapper/$name" "/mnt/$name" && \
df -h "/mnt/$name" && \

echo "DONE!"

# TODO: Show lines for fstab and crypttab