#!/bin/bash
NUM_ARGS=$#

echo
echo "###############################################"
echo "#     dm-crypt LUKS Container MAKER - 0.1     #"
echo "###############################################"
echo

if [ $NUM_ARGS -ne 2 ] ; then
    echo Wrong number of arguments.
    echo Usage: [size in MB] [file to create]

else
    SIZE=$1
    FILE=$2

    # create file
    echo "Creating $FILE with a size of ${SIZE}MB"
    fallocate -v -l ${SIZE}MB $FILE

    # randomize file contents
    echo
    echo "Randomizing content"
    dd if=/dev/urandom of=$FILE bs=1MB count=$SIZE

    # creating a dm-crypt LUKS Container in the file
    echo
    echo "Creating dm-crypt LUKS Container (AES-XTS-PLAIN64, 256, SHA512)"
    cryptsetup -v -q --cipher aes-xts-plain64 --key-size 512 --hash sha512 --iter-time 5000 --use-urandom --verify-passphrase luksFormat $2

    # modify owner
    echo
    echo "Modifying permissions"
    chown unknown:unknown $FILE
    chmod 660 $FILE
fi