Subject: [TLS] Erik Kline's No Objection on draft-ietf-tls-external-psk-importer-06: (with COMMENT)

From: Erik Kline via Datatracker <[email-masked]>
Date: Mon, 28 Dec 2020 22:50:20 -0800

Erik Kline has entered the following ballot position for
draft-ietf-tls-external-psk-importer-06: 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
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-tls-external-psk-importer/

----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------

[[ questions ]]

[ section 4.2 ]

* I'm insufficiently versed in TLS and HKDF to know for sure, but the text
  about "replace the string" and the diagrammed example don't seem to agree,
  **to my untrained eye**.  The example seems to show "imp binder" perhaps
  concatenated with the "standard" sequence, rather than "imp binder"
  /replacing/ "ext binder".

  Am I way off base here? In other words, should

    "ext binder" | "res binder" | "imp binder"

  actually be (if I understand the use of the word "replace" correctly):

    "imp binder" | "res binder"

  ?

  I will happily differ to others more knowledgeable than myself
  (essentially: almost everybody).

[[ nits ]]

[ section 3 ]

* "are bound a target protocol" -> "are bound to a target protocol"

---

From: Benjamin Kaduk <[email-masked]>
Date: Tue, 29 Dec 2020 18:16:32 -0800

> https://datatracker.ietf.org/doc/draft-ietf-tls-external-psk-importer/

I guess https://tools.ietf.org/html/rfc8446#section-7.1 does not cover this
very well either, but the '|' notation is just shorthand for "there are
multiple outputs, produced by using the different values as this input
field".  It's not concatenation, just a different output corresponding to
the different case of protocol operation.

Suggestions for how to clarify that would, of course, be most welcome!

Thanks,

Ben

---

From: Erik Kline <[email-masked]>
Date: Tue, 29 Dec 2020 21:51:06 -0800

Ah, I suspected I was missing something.  "|" here is used for alternation,
not concatenation, I (now) gather.  The existing text makes sense.

Probably no clarification is required for readers who are actually
implementers.  I suppose if someone wanted to add text then just a simple
parenthetical " (here '|' is used for alternation, not concatenation)"
would suffice.  But I've no strong feelings.

Thanks for the clue!

On Tue, Dec 29, 2020 at 6:16 PM Benjamin Kaduk <[email-masked]> wrote:

> > Please refer to
> https://www.ietf.org/iesg/statement/discuss-criteria.html