Re: [STDS-802-11-TGM] Teleconference reminder: June 14 @ 10am ET, re 21/

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I suggest the following for this round, which consistently enumerates the conditions

for the not-always-included things:

An SAE Commit message shall include a Finite Cyclic Group field (see 9.4.1.42 (Finite Cyclic Group field)) indicating a group, a Scalar field (see 9.4.1.39 (Scalar field)) containing the scalar, and an FFE field containing the element (see 9.4.1.40 (FFE field)).

If the SAE Commit message is in response to an Anti-Clogging Token field request (see 12.4.7.6 (Status codes)), an Anti-Clogging Token field shall be included (see 9.4.1.38 (Anti-Clogging Token field)). When the PWE is derived using the hash-to-element method, the Anti-Clogging Token field is encapsulated in an Anti-Clogging Token Container element; otherwise, the Anti-Clogging Token field is included in the frame outside of an element as described in Table 9-41 (Presence of fields and elements in Authentication frames).

If a password identifier is used in generation of the password element (PWE) a Password identifier element shall be included and the identifier shall be encoded as a UTF-8 string in the Identifier portion of the element (see 9.4.2.216 (Password Identifier element)), otherwise it shall not be included.

If the status code is set to SAE_HASH_TO_ELEMENT and any groups have been rejected during the current SAE session, a Rejected Groups element (see 9.4.2.246 (Rejected Groups element)) shall be included, otherwise it shall not be included.

If an SAE Commit message with status code set to SAE_HASH_TO_ELEMENT is being sent in response to rejection of a previous SAE Commit message with status code set to UNSUPPORTED_FINITE_CYCLIC_GROUP , the group that was rejected shall be appended, after the rejected groups from previous attempts if any, to the Rejected Groups field of the Rejected Groups element.

Again, the previous text, whose construction you seem to be feverishly working to match, is discussing how to generate this present new request, the message currently being worked assembled, based on the immediate response you just got. The new text which is the final sentence I'm adding is not about construction of a new request based on the immediate response. In fact, the behavior depends on potentially many previous responses you had gotten. And the way you know, presently, what to do is whether "any groups have been rejected during the current SAE session." That's the key. That's why your text not satisfactory. Let me try, again, to describe it.

Alice Bob

group 19 --->

<--- reject, bad group

group 20, 19 rejected --->

<--- reject, anti-clogging token

And here we are! Now your text is somewhat unclear about what to do. The SAE Commit message with status set to SAE_HASH_TO_ELEMENT is being sent in response to an anti-clogging token. But your text says "a previous SAE Commit message." But this current SAE Commit message is not being sent in response to a previous one, it's being sent in response to the most recent one, the anti-clogging token request.

I'm confused. Your 21/0871r1 also has this "a previous SAE Commit message"

which you are now objecting to:

If an SAE Commit message with status code set to SAE_HASH_TO_ELEMENT is being sent in response to rejection of a previous SAE Commit message with status code set to UNSUPPORTED_FINITE_CYCLIC_GROUP, the group that was rejected shall be appended, after the rejected groups from previous attempts if applicable, to the Rejected Groups field of the Rejected Groups element.

The only change I am proposing in this sentence is to change "if applicable" to

"if any".

I agree "rejection of a previous SAE Commit" message is "somewhat unclear".

I think I pointed this out before, but I had understood from your response then

that you were not disposed to address this in this round. I'm more than happy

to address it in this round if you've changed your mind. What do you think

would make that sentence from 21/0871r1 clearer?

One does not send messages in response to previous messages.

[I don't understand this sentence. It seems self-evidently false to me.]

What we need the message to look like is:

token, group 20, 19 rejected --->

And that is exactly what my text says one should do! This message is being sent in response to an anti-clogging token rejection so the text that says if this message is being sent in response to an anti-clogging token rejection to include the token. Also, since there have been rejections during the current SAE session the rejected groups element is there.

So the text is not symmetric and each sentence is not constructed identically. So what. It makes sense and that's what matters. Your text, which having a "consistency" in sentence construction throughout the paragraph is confusing and will likely result in more people doing the wrong thing.

Again, the issue is that someone was including an empty Rejected Groups element so I am attempting to retain description of the correct behavior (see the handshake above) while mandating that if no bad group rejections have been received "during the current SAE session" then you don't include the Rejected Groups element.

As far as I can tell my proposal covers all this. Let me add some headings

to illustrate this:

Stuff that's always in the SAE Commit message

Inclusion of ACT, in response to ACT request

Inclusion of password identifier, iff used for PWE generation

Inclusion of Rejected Groups element, iff any groups have been rejected in this session (whether or not rejected in the immediately preceding message)

Addition of stuff to the Rejected Groups element ("a previous" is vague, but intent is to be the immediately preceding message I think)

Thanks,

Mark

Mark RISON, Standards Architect, WLAN English/Esperanto/Français

Samsung Cambridge Solution Centre Tel: +44 1223 434600

Innovation Park, Cambridge CB4 0DS Fax: +44 1223 434601

ROYAUME UNI WWW: http://www.samsung.com/uk

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Re: [STDS-802-11-TGM] Teleconference reminder: June 14 @ 10am ET, re 21/0871 (Rejected Groups in SAE)