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Re: [TLS] Implicit ACKs in post-handshake

Christopher Wood <caw@heapingbits.net> Fri, 24 April 2020 23:50 UTC

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Date: Fri, 24 Apr 2020 16:49:44 -0700
From: Christopher Wood <caw@heapingbits.net>
To: "TLS@ietf.org" <tls@ietf.org>
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Subject: Re: [TLS] Implicit ACKs in post-handshake
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On Thu, Apr 23, 2020, at 5:23 PM, Eric Rescorla wrote:
> 
> 
> On Thu, Apr 23, 2020 at 4:58 PM Martin Thomson <mt@lowentropy.net> wrote:
> > What makes this case interesting is the non-machine time that might exist between receiving CertificateRequest and sending Certificate.
> > 
> >  In most of the exchanges, we expect there to be an answer that is immediately available, so that the implicit ACK works. Here we have to recognize that ACK might need to be sent anyway if the Certificate message is going to take time to source.
> > 
> >  If we don't have something already, it might pay to at least mention that if there are significant delays involved in preparing a response, an ACK SHOULD be sent rather than relying on implicit acknowledgment.
> 
> That text is already there, thanks to Hanno.

Indeed. Given this recent addition, perhaps it's easiest to do nothing. 

Best,
Chris (no hat)

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