Re: [quicwg/base-drafts] Padding requirement seems to be incorrect. (#3053)

Martin Thomson <notifications@github.com> Thu, 10 October 2019 02:12 UTC

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Date: Wed, 09 Oct 2019 19:11:57 -0700
From: Martin Thomson <notifications@github.com>
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Subject: Re: [quicwg/base-drafts] Padding requirement seems to be incorrect. (#3053)
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The insight I had here was this:

If you are sending Initial, it is possible that this is the only packet in the datagram that can be processed by your peer.  If that is the case, then a client needs to ensure that it pads the datagram as though no other packets were present.

You can infer from the fact that you have Handshake keys that the server is able to process Handshake packets, and then extend that to say that if you include Handshake packets then the server won't need padding.  But then you can extend that inference to saying that there is no need to send any Initial packets (as the current draft does; currently, you are not required to keep Initial keys once you are sending with Handshake keys).

Either way, I figure that it is better to keep things simple and say "if Initial, pad".  In those cases where padding ends up being excessive, it's only excessive for a short while.

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