Re: [TLS] Kathleen Moriarty's Yes on draft-ietf-tls-cached-info-20: (with COMMENT)

Stephen Farrell <stephen.farrell@cs.tcd.ie> Thu, 17 December 2015 15:09 UTC

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To: Kathleen Moriarty <Kathleen.Moriarty.ietf@gmail.com>, The IESG <iesg@ietf.org>
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From: Stephen Farrell <stephen.farrell@cs.tcd.ie>
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Subject: Re: [TLS] Kathleen Moriarty's Yes on draft-ietf-tls-cached-info-20: (with COMMENT)
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On 17/12/15 14:58, Kathleen Moriarty wrote:
> Kathleen Moriarty has entered the following ballot position for
> draft-ietf-tls-cached-info-20: Yes
> 
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> Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html
> for more information about IESG DISCUSS and COMMENT positions.
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> The document, along with other ballot positions, can be found here:
> https://datatracker.ietf.org/doc/draft-ietf-tls-cached-info/
> 
> 
> 
> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
> 
> Just a quick comment, sorry for asking this late and I won't hold up on
> it either, just want to raise the question without quite enough time to
> research it all.
> 
> I see the SHA-256 truncation is just 32 bits.  In other applications,
> about half is what is typically recommended.  I know you are trying to
> cut on space, but will problems arise from this shorter value?

Nah, I think this one's ok. IIUC, the result of a collision is
just a handshake fail, and then presumably recovery when they
ditch the cached stuff. Section 5 describes this.

S.


> 
>