Re: [TLS] COMMENT: draft-ietf-tls-renegotiation

Peter Saint-Andre <stpeter@stpeter.im> Mon, 14 December 2009 20:36 UTC

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Date: Mon, 14 Dec 2009 13:36:39 -0700
From: Peter Saint-Andre <stpeter@stpeter.im>
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Subject: Re: [TLS] COMMENT: draft-ietf-tls-renegotiation
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On 12/14/09 12:44 PM, Nicolas Williams wrote:
> On Mon, Dec 14, 2009 at 11:19:57AM -0800, Russ Housley wrote:
>>   As a protocol climbs the IETF standards-track maturity ladder, we
>>   sometimes drop features.  I would rather see renegotiation dropped
>>   from TLS than see this complexity added to TLS protocol.
> 
> I would like to agree.  There's no real-world need to re-negotiate for
> re-keying nowadays: with the advent of 128-bit block block ciphers
> there's little need.
> 
> But re-negotiation remains useful for other purposes.  Probably the most
> obvious ones are optional authentication and privacy protection for
> client credentials.  I'm not sure those are sufficiently useful or
> important to warrant keeping the feature, but if not then dropping the
> feature does seem like a better option than fixing it.

Even if the WG decided not to drop renegotiation, I do think it would be
helpful to document why the feature is important and useful in the first
place. As far as I can see, both draft-ietf-tls-renegotiation and
draft-mrex-tls-secure-renegotiation assume that renegotiation is a good
thing, and RFC 5246 contains only this assertion:

      While renegotiation is an optional feature, supporting it is
      highly recommended.

A more detailed justification might be helpful.

Peter

-- 
Peter Saint-Andre
https://stpeter.im/