Re: stateless reset in response to packet that is 43 bytes

Ian Swett <ianswett@google.com> Mon, 01 June 2020 04:54 UTC

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From: Ian Swett <ianswett@google.com>
Date: Mon, 1 Jun 2020 00:54:11 -0400
Message-ID: <CAKcm_gNF3rLJ8_eAOTwukhW+uYM1oTSzjA3a3Xm2bW7fYiNjNg@mail.gmail.com>
Subject: Re: stateless reset in response to packet that is 43 bytes
To: Martin Thomson <mt@lowentropy.net>
Cc: IETF QUIC WG <quic@ietf.org>
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I believe we assumed 1 byte of payload as well, so I believe 43 is correct.

On Sun, May 31, 2020 at 9:34 PM Martin Thomson <mt@lowentropy.net> wrote:

> The packet with a short header that has the lowest length, but a
> maximum-length connection ID is 1 (type) + 20 (destination connection ID) +
> 4 (packet number + data) + 16 (aead expansion) = 41 bytes.
>
> Hmm, maybe this should be 42 instead of 43.  I always get this bit wrong
> though.
>
> On Mon, Jun 1, 2020, at 02:55, Jiuhai Zhang wrote:
> > https://tools.ietf.org/html/draft-ietf-quic-transport-27#section-10.4
> > An endpoint that sends a stateless reset in response to
> >    packet that is 43 bytes or less in length SHOULD send a stateless
> >    reset that is one byte shorter than the packet it responds to.
> > Could someone explain why it is 43 bytes? thks
>
>