[dm-crypt] Re: Reading the passphrase from a key-file

On Fri, 14 May 2021 at 22:43, Milan Broz <[email protected]> wrote:
>
> On 14/05/2021 20:10, Clemens Fruhwirth wrote:
> > On Fri, 14 May 2021 at 17:51, Milan Broz <[email protected]> wrote:
> > But I don't think that you can produce output that is "the same"
> > regardless of key size with PBKDF2 -- at least in theory -- as the
> > derived key is a concatenation of xor-ed PRF outputs. If you disagree,
> > maybe you want to elaborate on that :).
>
> What I meant is that HMAC property in PBKDF2-HMAC, if the input is longer
> than internal block size of used hash (for SHA1 64 bytes), then it uses hash of input.
>
> So both input and SHA1(input) in PBKDF2-HMAC-SHA1 will produce the same derived key.
> https://en.wikipedia.org/wiki/PBKDF2#HMAC_collisions

Thank you, Milan, I wasn't aware of that property! TIL.

Best Regards, Clemens
-- 
Fruhwirth Clemens http://clemens.endorphin.org
_______________________________________________
dm-crypt mailing list -- [email protected]
To unsubscribe send an email to [email protected]