Subject: [Emu] Stephen Farrell's Yes on draft-ietf-emu-crypto-bind-04: (with COMMENT)

From: "Stephen Farrell" <[email-masked]>
Date: Thu, 15 Aug 2013 03:17:38 -0700

Stephen Farrell has entered the following ballot position for
draft-ietf-emu-crypto-bind-04: Yes

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COMMENT:
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3.2.3: this confused me "First, the server and peer
prove to each other knowledge of the inner MSK.  Then, the
inner MSK is combined into some outer key material to form
the tunnel's keys."  Reading that, the implication would
be that I form a tunnel, then inside the tunnel do EAP
resulting in the inner MSK, and after that I "form the
tunnel's keys" which seems impossible as I've used the
tunnel already so how can I "form" its keys? Do you
mean "confirm" instead? (And a nit: "combined into"
seems odd, "combined with" would be clearer for me.)

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From: Sam Hartman <[email-masked]>
Date: Thu, 15 Aug 2013 09:44:05 -0400

>>>>> "Stephen" == Stephen Farrell <[email-masked]> writes:

    Stephen> Stephen Farrell has entered the following ballot position
    Stephen> COMMENT: ----------------------------------------------------------------------

    Stephen> 3.2.3: this confused me "First, the server and peer prove
    Stephen> to each other knowledge of the inner MSK.  Then, the inner
    Stephen> MSK is combined into some outer key material to form the
    Stephen> tunnel's keys."  Reading that, the implication would be
    Stephen> that I form a tunnel, then inside the tunnel do EAP
    Stephen> resulting in the inner MSK, and after that I "form the
    Stephen> tunnel's keys" which seems impossible as I've used the
    Stephen> tunnel already so how can I "form" its keys? Do you mean
    Stephen> "confirm" instead? (And a nit: "combined into" seems odd,
    Stephen> "combined with" would be clearer for me.)

No your first reading is correct.
Perhaps tunnel's EAP keys would make it more clear.
At the end of tunnel setup after inner EAP methods are run, the MSK and
EMSK for the tunnel are generated.
Obviously the traffic keys for the tunnel are generated much earlier.

I'm happy if you and Shawn agree on an RFC editor note to do something
like say tunnel's EAP keys and use combined with

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From: Stephen Farrell <[email-masked]>
Date: Thu, 15 Aug 2013 14:56:36 +0100

Hi Sam,

> Perhaps tunnel's EAP keys would make it more clear.

It would.

> like say tunnel's EAP keys and use combined with

That'd work for me.
Ta,
S.

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From: Sean Turner <[email-masked]>
Date: Thu, 15 Aug 2013 10:16:02 -0400

>> like say tunnel's EAP keys and use combined with

Sam,

I'll get Stephen to shoot me some text and we'll add it in as an RFC 
editor note to get this one approved today.

spt