veracrypt-delete

#!/bin/sh

# Make sure there is exactly one argument given (a file)
if [ $# != 1 ] || ! [ -f "$1" ]; then
	echo 'Invalid arguments given, this script accepts exactly one argument, which is the file that should be deleted' >&2
	exit 1
fi

# Make sure that the user wants to continue
echo 'This script deletes veracrypt container files by firstly overwriting the header and backup header area of the given file and then deleting it'
echo ''
read -p "Are you sure you want to continue deleting '$1' ? (y/n) "
if ! [[ "$REPLY" =~ ^[Yy] ]]; then
	exit 0
fi

# Get size of file
FILESIZE="$(stat -c %s "$1")"

# Check for errors (196608B=192KiB is the minimal filesize for valid container file)
if ! echo -n "$FILESIZE" | grep -qE '[0-9]+' || [ "$FILESIZE" -lt 196608 ]; then
	echo 'Abort! Could not get filesize or file was to small' >&2
	exit 1
fi

# Remove first 128KiB (overwrite multiple time to make sure)
dd if=/dev/urandom of="$1" bs=64K count=2 status=none
dd if=/dev/urandom of="$1" bs=64K count=2 status=none
dd if=/dev/urandom of="$1" bs=64K count=2 status=none

# Check for errors
if [ $? != 0 ]; then
	echo 'Abort! Something went wrong' >&2
	exit 1
fi

# Remove last 64KiB (overwrite multiple time to make sure)
echo $FILESIZE_KIB
dd if=/dev/urandom of="$1" obs=1B seek="$FILESIZE" bs=64K count=1 status=none
dd if=/dev/urandom of="$1" obs=1B seek="$FILESIZE" bs=64K count=1 status=none
dd if=/dev/urandom of="$1" obs=1B seek="$FILESIZE" bs=64K count=1 status=none

# Check for errors
if [ "$?" != 0 ]; then
	echo 'Abort! Something went wrong' >&2
	exit 1
fi

# Delete the file
env rm "$1" || echo 'Error while deleting file' >&2; exit 1

echo 'Completed without errors'