#!/bin/bash

PASS=`< /dev/urandom tr -dc A-Za-z0-9'"<>,./?!@#$%^&(){}[]' | head -c8`
oldPassword="Test2001"
newPassword=$PASS
rootdevice="/dev/sda3"
printf '%s\n' "$oldPassword" "$newPassword" "$newPassword" |sudo cryptsetup luksAddKey $rootdevice
printf '%s\n' "$oldPassword" |sudo cryptsetup luksRemoveKey $rootdevice
echo $newPassword