Re: [Cbor] I-D Action: draft-ietf-cbor-network-addresses-04.txt

Michael Richardson <mcr+ietf@sandelman.ca> Sun, 25 April 2021 10:40 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: otroan@employees.org
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Date: Fri, 23 Apr 2021 18:22:40 -0400
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Subject: Re: [Cbor] I-D Action: draft-ietf-cbor-network-addresses-04.txt
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otroan@employees.org wrote:
    > Do you want to say anthing about tag 261 or perhaps subsume tag 261
    > into this?

Hi, I wasn't happy with tag 260/261.
In addition to not distinguishing between v4 and v6 explicitely, tag 260 also
confused 6-byte ethernet into the definition, and did not accomodate 8-byte
ethernet.
Tag 261 (on prefixes), I did not understand, which is why I wrote the document.

    > Why do you have "Trailing zero bytes MUST be omitted." as it seems the
    > decoder would happily deal with trailing zeros?

Yes, well Postel rule definitely applies here.

For prefixes, a concern was expressed that irrelvant bits could be included
and could form some kind of intentional convert channel.  Worse, they could
be a non-intentional leak of private information (a la Heartbleed).
So, it might be good to be able to make sure that encoders were more conservative.

--
Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide