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Re: [TLS] DSS with other than SHA-1 algorithms

Dr Stephen Henson <lists@drh-consultancy.demon.co.uk> Thu, 10 February 2011 15:08 UTC

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Date: Thu, 10 Feb 2011 15:08:41 +0000
From: Dr Stephen Henson <lists@drh-consultancy.demon.co.uk>
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Subject: Re: [TLS] DSS with other than SHA-1 algorithms
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On 10/02/2011 15:05, Nikos Mavrogiannopoulos wrote:
> On Thu, Feb 10, 2011 at 10:49 AM, Peter Gutmann
> <pgut001@cs.auckland.ac.nz> wrote:
> 
>>> How does this apply to TLS 1.0 and 1.1 messages "Server Key Exchange" and
>>> "Certificate verify" that sign the handshake data? How is the peer going to
>>> understand which hash is being used?
>> It's always SHA-1.
> 
> So here there is a choice either to violate FIPS-186-3 or TLS 1.0. If you use
> SHA-1 you violate the FIPS-186-3, but if you don't you violate TLS 1.0
> that requires 20 bytes of SHA-1... Quite some situation :)
> 

FIPS 186-3 also makes comments about RSA too, you can have just as much fun with
those.

Steve.
-- 
Dr Stephen N. Henson.
Core developer of the   OpenSSL project: http://www.openssl.org/
Freelance consultant see: http://www.drh-consultancy.co.uk/
Email: shenson@drh-consultancy.co.uk, PGP key: via homepage.

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