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

Nikos Mavrogiannopoulos <nmav@gnutls.org> Thu, 10 February 2011 15:05 UTC

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Date: Thu, 10 Feb 2011 16:05:15 +0100
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From: Nikos Mavrogiannopoulos <nmav@gnutls.org>
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>
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Subject: Re: [TLS] DSS with other than SHA-1 algorithms
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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 :)

regards,
Nikos

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