Arguments changes & checks

Signed-off-by: Bogdan Purcareata <bogdan.purcareata@gmail.com>
Add suffix as supported image parameter

Signed-off-by: Bogdan Purcareata <bogdan.purcareata@gmail.com>
Reading structures in hide_message

Signed-off-by: Bogdan Purcareata <bogdan.purcareata@gmail.com>
Finalize hashing & minor refactoring

Signed-off-by: Bogdan Purcareata <bogdan.purcareata@gmail.com>
Added support for zeroizing image

Signed-off-by: Bogdan Purcareata <bogdan.purcareata@gmail.com>