From: "Jorge Fábregas" <jorge.fabregas@gmail.com>
To: dm-crypt@saout.de
Subject: Re: [dm-crypt] MK Digest Size
Date: Sun, 10 Jul 2011 12:59:51 -0400 [thread overview]
Message-ID: <4E19DA87.5060000@gmail.com> (raw)
In-Reply-To: <4E19D356.7020504@gmail.com>
On 07/10/2011 12:29 PM, Jorge Fábregas wrote:
> I still get to see 20 HEX characters (160 bits) for the MK digest?
I'm sorry. I meant 20 pairs of HEX characters (40 chars) as they appear
nicely formatted in the luksDump output.
> Shouldn't I see 32 HEX chars (256 bits)?
Same here (64 hex characters ).
> Or is that sha256 is used in the PBKDF2 process but the function is
> instructed to deliver just 160 bits?
Ok, I'm going to try to answer myself as I just read again the latest
specification. It appears this is the case (just 160 bits even if you
use sha256) because there are just 20 bytes available for "mk-digest" in
the header.
I'm just curious: is having just 20 bytes for the digest a limitation
here? Are there any plans to expand this field in the future?
> One final thing just to make sure: is the algorithm that appears under
> "Hash spec" in the header..is this the same hash-algorithm used (along
> with PBKDF2) for the user-keys? as well as the one used with PBKDF2 for
> the MK digest?
Apparently yes.
Sorry for the noise!
Regards,
Jorge
next prev parent reply other threads:[~2011-07-10 16:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-10 16:29 [dm-crypt] MK Digest Size Jorge Fábregas
2011-07-10 16:59 ` Jorge Fábregas [this message]
2011-07-10 18:17 ` Milan Broz
2011-07-10 18:26 ` Jorge Fábregas
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