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

Nikos Mavrogiannopoulos <nmav@gnutls.org> Thu, 10 February 2011 16:05 UTC

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Date: Thu, 10 Feb 2011 17:05:59 +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 4:46 PM, Peter Gutmann
<pgut001@cs.auckland.ac.nz> wrote:
>>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 :)
> Not really, use of DSA server certs is practically nonexistent (anyone want to
> trawl through the EFF cert database to count them?) and use of "DSA2" (i.e. >
> 1 kbit key) certs AFAIK *is* nonexistent, so it's nothing to worry about.  To
> look at it another way, worrying about this is like worrying about what colour
> unicorns are.

Well, it is chicken and egg problem. If they cannot be used in practice with any
application because the spec is not clear, no-one will use them. If the spec was
clear, and interoperable implementations could be made then, someone could
apply for a certificate with a DSA key. But anyway since it's supposed to
be supported by TLS, it should be clarified, otherwise it's better to drop it
completely...

regards,
Nikos

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