Subject: [Emu] Protocol Action: 'Channel Binding Support for EAP Methods' to Proposed Standard (draft-ietf-emu-chbind-16.txt)

From: The IESG <[email-masked]>
Date: Fri, 25 May 2012 13:39:19 -0700

The IESG has approved the following document:
- 'Channel Binding Support for EAP Methods'
  (draft-ietf-emu-chbind-16.txt) as Proposed Standard

This document is the product of the EAP Method Update Working Group.

The IESG contact persons are Sean Turner and Stephen Farrell.

A URL of this Internet Draft is:
http://datatracker.ietf.org/doc/draft-ietf-emu-chbind/

Technical Summary

   This document defines how to implement channel bindings for
   Extensible Authentication Protocol (EAP) methods to address
   the lying NAS as well as the lying provider problem.

Working Group Summary

   This document has had extensive review in the EMU working
   group. The document has clear applicability in ABFAB and
   Network Access use cases.

Document Quality

   Project Moonshot, an ABFAB implementation, is working on an
   implementation of this document. 

Personnel

  Joe Salowey ([email-masked]), EMU working group co-chair, is the
  Working Group Shepherd for this document.
  Sean Turner ([email-masked]) is the responsible AD.

RFC Editor Note

Two things:

1) s9.1: r/subvirt/subvert

2) Title page (xml2rfc fun on the title page):

OLD:

                                         T. Clancy
                  Department of Electrical
Engineering and Computer Science

NEW:

                                         T. Clancy
                                   Virginia Tech

---

From: [email-masked]
Date: Fri, 1 Jun 2012 10:11:48 +0800

I found 3 references may be helpful:

1. http://tools.ietf.org/html/draft-ohba-eap-channel-binding-02

[EAP-CHANNEL]  Ohba, Y., Parthasrathy, M., and M. Yanagiya, "Channel
                  Binding Mechanism Based on Parameter Binding in Key
                  Derivation", 

   In this approach the  EAP method includes channel binding parameters in 
the calculation of
   exported EAP keying material, making it impossible for the peer and
   authenticator to complete the Secure Association Protocol if there is
   a mismatch in the channel binding parameters.  However, this approach
   can only be applied where methods generating EAP keying material are
   used along with lower layers that utilize EAP keying material.  For
   example, this mechanism would not enable verification of channel
   binding on wired IEEE 802 networks using [IEEE-802.1X].

It talked about technique mentioned in current channel binding.

2. in rfc 5247 section  5.3.4.  Mutual Authentication
  Using EMSK in crypto binding was mentioned, maybe helpful in current 
crypto binding
 
  "Since  the compound key MUST NOT be known to an attacker posing as an
   authenticator, and yet must be derived from EAP keying material, it
   MAY be desirable to derive the compound key from a portion of the
   EMSK.  Where this is done, in order to provide proper key hygiene, it
   is RECOMMENDED that the compound key used for man-in-the-middle
   protection be cryptographically separate from other keys derived from
   the EMSK."

3. also in rfc 5247
 
   TEKs are output from EAP methods and were designed to secure the 
channel,
   couldn't they be used in channel binding or crypto binding? 
 
  "Transient EAP Keys (TEKs)
      Session keys that are used to establish a protected channel
      between the EAP peer and server during the EAP authentication
      exchange.  The TEKs are appropriate for use with the ciphersuite
      negotiated between EAP peer and server for use in protecting the
      EAP conversation.  The TEKs are stored locally by the EAP method
      and are not exported.  Note that the ciphersuite used to set up
      the protected channel between the EAP peer and server during EAP
      authentication is unrelated to the ciphersuite used to
      subsequently protect data sent between the EAP peer and
      authenticator.
"
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+         ---+
|                                                         |            ^
|                EAP Method                               |            |
|                                                         |            |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   +-+-+-+-+-+-+-+   |            |
| |                                 |   |             |   |            |
| |       EAP Method Key            |<->| Long-Term   |   |            |
| |         Derivation              |   | Credential  |   |            |
| |                                 |   |             |   |            |
| |                                 |   +-+-+-+-+-+-+-+   |  Local to  |
| |                                 |                     |       EAP  |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                     |     Method |
|   |             |               |                       |            |
|   |             |               |                       |            |
|   |             |               |                       |            |
|   |             |               |                       |            |
|   |         +-+-+-+-+-+-+ +-+-+-+-+-+-+ +-+-+-+-+-+-+-+ |            |
|   |         | TEK       | |MSK, EMSK  | |IV           | |            |
|   |         |Derivation | |Derivation | |Derivation   | |            |
|   |         |           | |           | |(Deprecated) | |            |
|   |         +-+-+-+-+-+-+ +-+-+-+-+-+-+ +-+-+-+-+-+-+-+ |            |
|   |               ^             |               |       |            |
|   |               |             |               |       |            V
+-+-|-+-+-+-+-+-+-+-|-+-+-+-+-+-+-|-+-+-+-+-+-+-+-|-+-+-+-+         ---+
    |               |             |               |                    ^
    |               |             |               |           Exported |
    | Peer-Id(s),   | channel     | MSK (64+B)    | IV (64B)      by   |
    | Server-Id(s), | bindings    | EMSK (64+B)   | (Optional)    EAP  |
    | Session-Id    | & Result    |               |             Method |
    V               V             V               V                    V

Regards~~~

-Sujing Zhou

[email-masked] 写于 2012-05-26 04:39:19:

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