Re: [OAUTH-WG] Barry Leiba's No Objection on draft-ietf-oauth-spop-14: (with COMMENT)

[John Bradley <[e-mail]>]

I have a draft with Barry’s edits less the removal of ASCII(string) ready to go.

In JWS we used ASCII(string) to indicate that the output is a sequence of octets, strings are not necessarily 8 characters bits and may have null termination etc.

However as Brian states other changes may have removed the need for that.

I admit saying "where STRING is a sequence of zero or more ASCII characters.” looks a bit circular.   How about saying "where STRING is a sequence of zero or more characters”

The ABNF in Sec 4.1 should keep people from going too wrong on its own.

I think it is OK the way it is, but am willing to change it if people feel strongly.

Let me know if I should make that change or publish a draft without it, addressing the other comments.

John B.




> On Jul 7, 2015, at 5:40 PM, Kathleen Moriarty <[e-mail]> wrote:
> 
> Thanks for your responses on these comments.
> 
> I can approve an updated draft to make this change and the one for IANA if that is the easiest path.  The other option is to write this all up in an RFC editor note and I can send that with the approval.  Making the direct updates may be simpler to avoid mistakes.
> 
> Can you submit a new version?
> 
> Thank you,
> Kathleen
> 
> On Tue, Jul 7, 2015 at 12:35 PM, Brian Campbell <[e-mail] <mailto:[e-mail]>> wrote:
> Regarding the comment on Section 2, I had originally argued for the inclusion of ASCII(xxx) as I felt it was important to avoid potential ambiguity that was in the draft at the time (it wasn't 100% clear to me at the time if the code_verifier was to be base64url decoded as input into the hash or if the ASCII bytes were to be used). However, other content (particularly §4.1 <https://tools.ietf.org/html/draft-ietf-oauth-spop-14#section-4.1>) has since changed and removed the potential for the ambiguity I thought might be there. 
> 
> Which is a long way of explaining that I'm okay with Barry's proposed change to Section 2, and occurrences of ASCII(...) throughout, despite it undoing something I'd previously requested.  
> 
> On Tue, Jul 7, 2015 at 10:09 AM, Nat Sakimura <[e-mail] <mailto:[e-mail]>> wrote:
> Thanks Barry, 
> 
> 
> These are the issues that I wanted to discuss with John before making change. 
> 
> -- Section 6.2 -- John has partly addressed your IANA comment already. I needed 
> to check if there was any reason for just doing partly. 
> 
> -- Section 7.2 -- is probably just my oversight. I will deal with it. 
> 
> -- Section 2 -- : I agree with you and I wanted to confirm it with John and other people to commit the change. 
> 
> Cheers, 
> 
> Nat
> 
> 2015-07-07 11:49 GMT+09:00 Barry Leiba <[e-mail] <mailto:[e-mail]>>:
> Barry Leiba has entered the following ballot position for
> draft-ietf-oauth-spop-14: No Objection
> 
> When responding, please keep the subject line intact and reply to all
> email addresses included in the To and CC lines. (Feel free to cut this
> introductory paragraph, however.)
> 
> 
> Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html <https://www.ietf.org/iesg/statement/discuss-criteria.html>
> for more information about IESG DISCUSS and COMMENT positions.
> 
> 
> The document, along with other ballot positions, can be found here:
> https://datatracker.ietf.org/doc/draft-ietf-oauth-spop/ <https://datatracker.ietf.org/doc/draft-ietf-oauth-spop/>
> 
> 
> 
> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
> 
> Version -14 resolves my DISCUSS (and also some of my non-blocking
> comments).  Thanks very much for considering these and working with me on
> them!
> 
>   =========================================
> My comment about the IANA Considerations remains.  While it's
> non-blocking, I still hope you will accept the change I suggest:
> 
> -- Section 6.2 --
> I have the same comment here as in the other OAuth document: please shift
> the focus away from telling IANA how to handle tracking of the expert
> review, and make the mailing list something that the designated expert(s)
> keep track of.  Also, please give more instructions to the DEs about what
> they should consider when they're evaluating a request (for example,
> should they approve all requests, or are there criteria they should
> apply?).
> 
> For the first, here's a text change that I suggest we move toward for
> this sort of thing:
> 
> OLD
> <most of Section 6.2>
> 
> NEW
>    Additional code_challenge_method types for use with the authorization
>    endpoint are registered using the Specification Required policy
>    [RFC5226], which includes review of the request by one or more
>    Designated Experts.  The DEs will ensure there is at least a two-week
>    review of the request on the [e-mail] <mailto:[e-mail]> mailing list,
>    and that any discussion on that list converges before they respond to
>    the request.  To allow for the allocation of values prior to
>    publication, the Designated Expert(s) may approve registration once
>    they are satisfied that an acceptable specification will be
> published.
> 
>    Discussion on the [e-mail] <mailto:[e-mail]> mailing list should use
>    an appropriate subject, such as "Request for PKCE
>    code_challenge_method: example").
> 
>    The Designated Expert(s) should consider the discussion on the
>    mailing list, as well as <<these other things>> when evaluating
>    registration requests.  Denials should include an explanation
>    and, if applicable, suggestions as to how to make the request
>    successful.
> END
> 
>   =========================================
> -- Section 7.2 --
> I find the first first paragraph confusingly worded, and after discussion
> with the author I suggest this:
> 
> NEW
> Clients MUST NOT downgrade to "plain" after trying the S256 method.
> Because servers are required to support S256, an error when S256 is
> presented can only mean that the server does not support PKCE at all.
> Otherwise, such an error could be indicative of a MITM attacker trying
> a downgrade attack.
> END
> 
>   =========================================
> Finally, there is this comment, which is not a big deal and you should
> proceed as you think best:
> 
> -- Section 2 --
> There is no real distinction between STRING and ASCII(STRING), because
> STRING is already defined to be ASCII.  Using "ASCII(xxx)" only adds
> clutter, and a suggest removing it.
> 
> So, for example, that would result in changes such as this:
> 
> OLD
> BASE64URL-ENCODE(SHA256(ASCII(code_verifier))) == code_challenge
> NEW
> BASE64URL-ENCODE(SHA256(code_verifier)) == code_challenge
> END
> 
> 
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> 
> 
> 
> -- 
> Nat Sakimura (=nat)
> Chairman, OpenID Foundation
> http://nat.sakimura.org/ <http://nat.sakimura.org/>
> @_nat_en
> 
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> 
> 
> 
> 
> -- 
> 
> Best regards,
> Kathleen