Re: [jose] POLL(s): header criticality

"Manger, James H" <> Thu, 07 February 2013 11:04 UTC

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From: "Manger, James H" <>
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Date: Thu, 07 Feb 2013 22:04:18 +1100
Thread-Topic: [jose] POLL(s): header criticality
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Subject: Re: [jose] POLL(s): header criticality
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1. NO

2. NO

3. C -- one critical field; the definition of each value for this field implies what else you need to understand; if you want to add a new field that MUST be understood, just use a new value for the one critical field.

I second Richard's comment about YES to 2.

What would a JOSE library API look like if all fields MUST be understood by “the system”? Does the “top” layer tell the library what it understands; does the library return a list of unrecognized fields?

James Manger

From: [] On Behalf Of Richard Barnes
Sent: Thursday, 7 February 2013 6:02 AM
Subject: Re: [jose] POLL(s): header criticality


Further notes:

On SECOND POLL: Voting "Yes" on the SECOND POLL is equivalent to voting "NO" on the FIRST POLL.  If the requirement isn't placed on any particular element of the system, then nobody will implement it, and there will be no control.

On THIRD POLL: I don't care all that much about the specific syntax, but I have a strong preference that these non-critical fields be excluded from the integrity check that is applied to the header.  So I would prefer something like what Dick suggested, but encoded as a separate element of a JW* object.  As Breno notes, this can be done in a backwards compatible way.  (I voted "B" because I understood "A" to imply something like Mike's earlier proposal, which would have just had a list of field names.)

In any case, I would encourage the chairs to focus on the first poll, and view any results in the second and third as informative for further discussion of wording or syntax.

On Wed, Feb 6, 2013 at 1:47 PM, Nat Sakimura <<>> wrote:

2013/2/4 Karen O'Donoghue <<>>

I am wrestling with how to help drive consensus on the topic of criticality of headers. For background, please review the current specification text, the minutes to the Atlanta meeting (IETF85), and the mailing list (especially the discussion in December with (Subj: Whether implementations must understand all JOSE header fields)). We need to come to closure on this issue in order to progress the specifications.

As a tool to gather further information on determining a way forward, the following polls have been created. Please respond before 11 February 2013.


FIRST POLL: Should all header fields be critical for implementations to understand?

YES – All header fields must continue to be understood by implementations or the input must be rejected.

NO – A means of listing that specific header fields may be safely ignored should be defined.

SECOND POLL: Should the result of the first poll be "YES", should text like the following be added? “Implementation Note: The requirement to understand all header fields is a requirement on the system as a whole – not on any particular level of library software. For instance, a JOSE library could process the headers that it understands and then leave the processing of the rest of them up to the application. For those headers that the JOSE library didn’t understand, the responsibility for fulfilling the ‘MUST understand’ requirement for the remaining headers would then fall to the application.”

YES – Add the text clarifying that the “MUST understand” requirement is a requirement on the system as a whole – not specifically on JOSE libraries.

NO – Don’t add the clarifying text.

THIRD POLL: Should the result of the first poll be "NO", which syntax would you prefer for designating the header fields that may be ignored if not understood?

A – Define a header field that explicitly lists the fields that may be safely ignored if not understood.

B – Introduce a second header, where implementations must understand all fields in the first but they may ignore not-understood fields in the second.

C - Other??? (Please specify in detail.)
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Nat Sakimura (=nat)
Chairman, OpenID Foundation

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