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Re: [TLS] draft-turner-ssl-must-not

Nikos Mavrogiannopoulos <nmav@gnutls.org> Tue, 06 July 2010 15:05 UTC

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Date: Tue, 06 Jul 2010 16:40:35 +0200
From: Nikos Mavrogiannopoulos <nmav@gnutls.org>
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Cc: Marsh Ray <marsh@xs01.extendedsubset.com>, tls@ietf.org
Subject: Re: [TLS] draft-turner-ssl-must-not
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Martin Rex wrote:

>> There's no logic to it, or whatever there might be is too clever by half.
> 
> There appears to be a lack of logic by not adjusting the truncation size
> when going from a SHA-1 (=160 bits) based PRF to a SHA-256 (=256 bits)
> based PRF.  In case a 96 bit truncation is deemed adequate for SHA-1,
> then a truncation like 144 or 160 bits appears more appropriate for SHA-2.

Or just sending the whole output. I don't even know why truncation is
there. I'd understand truncation in the record layer HMAC that is sent
on every message, there it would save bandwidth... but on the finished
message?

regards,
Nikos

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