Re: [Cbor] [Ext] Roman Danyliw's No Objection on draft-ietf-cbor-7049bis-14: (with COMMENT)

Paul Hoffman <> Wed, 23 September 2020 19:30 UTC

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From: Paul Hoffman <>
To: Roman Danyliw <>
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Thread-Topic: [Ext] Roman Danyliw's No Objection on draft-ietf-cbor-7049bis-14: (with COMMENT)
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Date: Wed, 23 Sep 2020 19:30:16 +0000
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Subject: Re: [Cbor] [Ext] Roman Danyliw's No Objection on draft-ietf-cbor-7049bis-14: (with COMMENT)
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Thanks for your comments. Our notes are below.

--Paul Hoffman

> ----------------------------------------------------------------------
> ----------------------------------------------------------------------
> I support Ben Kaduk’s DISCUSS position.

We have dealt with that in a different thread.

> ** Section 1.0. Is it possible to enumerate the fixed errata?

It is possible, but does not seem important. They were issues in some examples.

> ** Section  For Tag 35, how does one know if the syntax is a PCRE or
> ECMA regular expression?

Fixed earlier in response to Ben.

> ** Section  PCRE is the only informative reference of all of the tags
> defined in this section (even ECMA is normative).  Please make it normative.

Fixed earlier in response to Ben.

> ** Section 4.1.  As an implementer of an application, what is the take away
> from this section?  I’m not following on the definition of “preferred”.

This section is signifying is that each application needs to specify which
serialization is being used for values with multiple serializations (such as
integer and bigint for the number "forty two"). It is not talking about a
universal preference, but one that each implementer needs to specify for their
particular application.

> ** Section 10.  Per “The input check itself may consume resources.  This is
> usually linear in the size of the input, which means that an attacker has to
> spend resources that are commensurate to the resources spent by the defender on
> input validation.”  I’m not sure this is true for all types of resources.  For
> example, with compute resources, as an attacker I can craft an input that will
> take longer for the target to process then for me to produce.

Good catch. We added text covering that.