Re: [TLS] Simplifying signature algorithm negotiation

Eric Rescorla <ekr@rtfm.com> Sat, 16 January 2016 01:23 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Fri, 15 Jan 2016 17:23:07 -0800
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To: David Benjamin <davidben@chromium.org>
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Cc: ekr <notifications@github.com>, "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Simplifying signature algorithm negotiation
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On Fri, Jan 15, 2016 at 5:19 PM, David Benjamin <davidben@chromium.org>;
wrote:

> On Fri, Jan 15, 2016 at 8:07 PM Dave Garrett <davemgarrett@gmail.com>;
> wrote:
>
>> On Friday, January 15, 2016 03:45:34 pm David Benjamin wrote:
>> > This is a proposal for revising SignatureAlgorithm/HashAlgorithm. In TLS
>> > 1.2, signature algorithms are spread across the handshake.
>> [...]
>> > I propose we fold the negotiable parameters under one name.
>> [...]
>> > 2. Remove HashAlgorithm, SignatureAlgorithm, SignatureAndHashAlgorithm
>> as
>> > they are. Introduce a new SignatureAlgorithm u16 type and negotiate that
>> > instead.
>>
>> I previously proposed this here:
>> https://www.ietf.org/mail-archive/web/tls/current/msg18035.html
>>
>> ekr was against it, though it hasn't been discussed that throughly.
>> https://www.ietf.org/mail-archive/web/tls/current/msg18036.html
>
>
> Ah, thanks! I must have missed this discussion. Or perhaps I saw it and
> forgot.
>
> ekr, are you still against this sort of thing? I think the new CFRG
> signature algorithms tying decisions together is a good argument for why
> we'd want this. If we believe this trend is to continue (and I hope it
> does. Ed25519 is a nice and simple interface), trying to decompose it all
> seems poor.
>

I'm not sure. I agree that the CFRG thing seems to be a new development.
I'll
try to confirm my previous opinion or develop a new one over the weekend :)

Ekr


> David
>
>
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