Subject: [Emu] Looking for reviewers

From: Alan DeKok <[email-masked]>
Date: Tue, 25 Sep 2012 17:04:12 +0200

We'd like to get the final two documents into last call before the
next meeting.  Therefore, we're looking for reviewers:

https://datatracker.ietf.org/doc/draft-ietf-emu-crypto-bind/

https://datatracker.ietf.org/doc/draft-ietf-emu-eap-tunnel-method/

  Please post reviews to the list.  If all goes well, we can get updated
documents issued before the next meeting.

  Thanks to everyone for their help.

  Alan DeKok.

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From: Simon Josefsson <[email-masked]>
Date: Tue, 25 Sep 2012 20:02:16 +0200

> https://datatracker.ietf.org/doc/draft-ietf-emu-eap-tunnel-method/

Section 5.3:

  The Compound MAC computation is as follows:

      CMK = CMK[j]
      Compound-MAC = HMAC-HASH( CMK, BUFFER )

   where j is the number of the last successfully executed inner EAP
   method, HASH is the default hash function or the alternative hash
   function negotiated in TLS 1.2 [RFC5246], and BUFFER is created after
   concatenating these fields in the following order:

TLS may negotiate MACs that are not based on HMAC.  Am I missing some
context here, or should this really be something like:

  The Compound MAC computation is as follows:

      CMK = CMK[j]
      Compound-MAC = MAC( CMK, BUFFER )

   where j is the number of the last successfully executed inner EAP
   method, MAC is the MAC function negotiated via TLS 1.2 [RFC5246], and
   BUFFER is created after concatenating these fields in the following
   order:

Section 5.1:

   derivation is "teap seesion key seed".  The length of the session key

Is this typo intentional?  I see it repeated in the IANA considerations
as well.

/Simon

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From: "Hao Zhou (hzhou)" <[email-masked]>
Date: Tue, 25 Sep 2012 18:55:48 +0000

Simon:

Thanks for the review. Good catch on both. We will fix both of them.

On 9/25/12 2:02 PM, "Simon Josefsson" <[email-masked]> wrote:

>_______________________________________________
>Emu mailing list
>[email-masked]
>https://www.ietf.org/mailman/listinfo/emu

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From: Jouni Malinen <[email-masked]>
Date: Wed, 26 Sep 2012 17:24:52 +0300

> Thanks for the review. Good catch on both. We will fix both of them.

What is the new Label for TLS Keying Material Exporter? "teap
session key seed"? If so, is there any reason to not follow the
recommended prefix for new uses as defined in RFC 5705 (see the relevant
text below)?

   Labels here have the same definition as in TLS, i.e., an ASCII string
   with no terminating NULL.  Label values beginning with "EXPERIMENTAL"
   MAY be used for private use without registration.  All other label
   values MUST be registered via Specification Required as described by
   RFC 5226 [RFC5226].  Note that exporter labels have the potential to
   collide with existing PRF labels.  In order to prevent this, labels
   SHOULD begin with "EXPORTER".  This is not a MUST because there are
   existing uses that have labels which do not begin with this prefix.

I would have expected to see something like "EXPORTER: teap session key
seed" used as the Label for EAP-TEAP.

Should the IANA Considerations section have somewhat more formal
language to request registration of the new exporter label?

   TEAP makes use of the TLS Keying Material Exporters defined in
   [RFC5705].  The Label used in the derivation as defined in
   Section 5.1 is "teap seesion key seed".

Maybe something like this:

TEAP registers the label "EXPORTER: teap session key seed" in the TLS
Exporter Label Registry. This label is used in derivation as defined in
Section 5.1.

-- 
Jouni Malinen                                            PGP id EFC895FA

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From: "Hao Zhou (hzhou)" <[email-masked]>
Date: Thu, 27 Sep 2012 14:24:51 +0000

Jouni:

Thanks for the suggestions. We will update that in the next draft.