Re: [TLS] A la carte concerns from IETF 93

Ilari Liusvaara <ilari.liusvaara@elisanet.fi> Thu, 23 July 2015 11:54 UTC

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Date: Thu, 23 Jul 2015 14:54:46 +0300
From: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
To: Dave Garrett <davemgarrett@gmail.com>
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Subject: Re: [TLS] A la carte concerns from IETF 93
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On Wed, Jul 22, 2015 at 04:10:27PM -0400, Dave Garrett wrote:
> Consensus was my current WIP proposal is not viable, for some of the following main reasons:
> 
> 1) cost/benefit analysis doesn't seem to be worth it
> 2) backwards compatibility handling
> 3) some argue harder to implement; others argue easier

IMO, the present situation is mainly problem for:

1) Users: Not having combinations they want (whitness the recent
   proposal for ECDHE_PSK ciphersuites). Sometimes leads to
   suboptimal ciphersuite choices.
2) TLS WG: Processing all the complaints about previous.
3) Admins: Configuring the mess.

What isn't in the list: TLS library authors: Most TLS libraries
have decoding tables (or equivalent) that break down ciphersuite
down to its component parts.


Using strict interpretation of TLS 1.2 rules, adding all the
relevant combinations would be about 100 ciphersuites (haven't
checked how many already exist).

Granted, not all of those are equally important. But that
brings question of what are important and what are not.

Also, if SHA-2 ever fails, defining the replacement ciphersuites
is going to be "fun".



-Ilari