Re: password hash in shadow file
- Date: Tue, 13 Mar 2018 17:47:46 +0100
- From: <tomas@xxxxxxxxxx>
- Subject: Re: password hash in shadow file
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On Tue, Mar 13, 2018 at 05:25:18PM +0100, Sven Hartge wrote:
> Adam Weremczuk <adamw@xxxxxxxxxxxxxxxxx> wrote:
> > I think it was me invoking "passwd" as root and aborting (ctrl+D)
> > without making any changes. Would that be enough to update the shadow
> > file?
> You can't reverse a hash and to generate a new hash the code needs the
> password for the user in plain.
Well, to be fair, the change to SHA-1 is because you can "reverse"
MD5 all too easily (where reverse just means that you find something
which hashes to a given hash, which hasn't to resemble your original
password all too much). Usually you want this something to have
some properties to be useful.
But I don't think your operating system is going to do that behind
your back ;-)
- -- t
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