[arch-general] Upgrading password hashes

[Chris Sakalis]

On Wed, Jul 11, 2012 at 11:16 AM, Kevin Chadwick <ma1l1ists at yahoo.co.uk> wrote:
>> By the way, is it possible to upgrade password hashes without an
>> intermediate password, assuming the new/old passwords are identical?
>
> You can have no password at all to start with but the system doesn't
> know the password, only what you entered matches. You could attack the
> md5 but that would be a waste of energy and likely time.
>

I do not think that this is what Nemo is asking. If you try to set
your password to the same one you already have, passwd fails with
"Password unchanged" and asks you again for a new password. So, if you
just want to update your hashes, you have to choose an intermediate
temporary password first and then change it again to the old one.