Internet DRAFT - draft-zhou-emu-ch-tunnel
draft-zhou-emu-ch-tunnel
EAP Method Update S. Zhou
Internet-Draft ZTE Corporation
Intended status: Standards Track July 6, 2012
Expires: January 7, 2013
Combination of Channel Binding and Tunnel Method
draft-zhou-emu-ch-tunnel-00
Abstract
This document proposes to incorporate channel binding as defined in
[I-D.ietf-emu-chbind ] into EAP tunnel method as soon as possible.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 7, 2013.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Zhou Expires January 7, 2013 [Page 1]
Internet-Draft draft-zhou-emu-ch-tunnel-00 July 2012
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Channel Binding after Tunnel Establishment . . . . . . . . . . 3
3. Channel Binding after the First Inner Method . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
6. Normative References . . . . . . . . . . . . . . . . . . . . . 4
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 5
Zhou Expires January 7, 2013 [Page 2]
Internet-Draft draft-zhou-emu-ch-tunnel-00 July 2012
1. Introduction
Channel binding as define in [I-D.ietf-emu-chbind] is used to
imitigate lying authenticator , and is implemented as part of the
ongoing EAP method, because the assertion transported from the EAP
server to EAP peer is authenticated by the resluting key (TEK, to be
more specific) derived from the EAP method. Although it is a bit
late to know the contacting authenticator is a liar after the peer
has completed the EAP method, it is a rather reasonable compromise to
the legacy EAP methods.
EAP Tunnel methods, e.g., defined in
[RFC4851][RFC5281][I-D.ietf-emu-eap-tunnel-method], are used to
protect weak EAP methods, especially some legacy EAP methods. When
it comes to using channel binding in tunnel methods, it is more
complex. To maximise the compatibility , channel binding may still
be carried out with the inner EAP method, using the inner TEK, or
some key derived from tunnel key (output from tunnel method) and
inner EAP method key, which has not been specified. This way, a peer
is assured of the honesty of the contacting authenticator only after
both the tunnel establishement and the completement of the inner EAP
method.
Since tunnel methods are used to protect the inner method, it might
be desirebale to provide channel binding simultaneously with or right
after the tunnel establishment.
1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. Channel Binding after Tunnel Establishment
When there is no inner EAP method after the tunnel
establishement,which is not ruled out in the current tunnel method
specification, or the inner method does not output key, channel
binding is carried out immediately after the tunnel establishment
according to the procedure defined in [I-D.ietf-emu-chbind], the key
used to authenticate the CB_Success or CB-Failure is derived from the
tunnel key TK and some shared secret (TEK) between EAP server and the
peer. TEK could be NULL if no shared secret can be provided at this
time.
In this case, when TEK is NULL, the certificate verification of the
EAP server (i.e., the tunnel server) is crucial, as pointed out in
Zhou Expires January 7, 2013 [Page 3]
Internet-Draft draft-zhou-emu-ch-tunnel-00 July 2012
[I-D.ietf-emu-crypto-bind].
3. Channel Binding after the First Inner Method
When some inner methods are carried out after the tunnel
establishment, and the first inner method outputs key, channel
binding is executed along with the first inner method, as defined in
[I-D.ietf-emu-chbind],the key used to authenticate the CB-Success or
CB_Failure is derived from the tunnel key TK and one of the outputs
of the first inner method , i.e., TEK.
4. IANA Considerations
This document includes no request to IANA.
5. Security Considerations
This document proposes to carry out channel binding as soon as
possible, in the case of EAP tunnel method is involved, to detect
rogueauthenticator as early as possible.
6. Normative References
[I-D.ietf-emu-chbind]
Hartman, S., Clancy, T., and K. Hoeper, "Channel Binding
Support for EAP Methods", draft-ietf-emu-chbind-16 (work
in progress), May 2012.
[I-D.ietf-emu-crypto-bind]
Hartman, S., Wasserman, M., and D. Zhang, "EAP Mutual
Cryptographic Binding", draft-ietf-emu-crypto-bind-00
(work in progress), June 2012.
[I-D.ietf-emu-eap-tunnel-method]
Zhou, H., Cam-Winget, N., Salowey, J., and S. Hanna,
"Tunnel EAP Method (TEAP) Version 1",
draft-ietf-emu-eap-tunnel-method-03 (work in progress),
June 2012.
[I-D.josefsson-pppext-eap-tls-eap]
Josefsson, S., Palekar, A., Simon, D., and G. Zorn,
"Protected EAP Protocol (PEAP) Version 2",
draft-josefsson-pppext-eap-tls-eap-10 (work in progress),
October 2004.
Zhou Expires January 7, 2013 [Page 4]
Internet-Draft draft-zhou-emu-ch-tunnel-00 July 2012
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4851] Cam-Winget, N., McGrew, D., Salowey, J., and H. Zhou, "The
Flexible Authentication via Secure Tunneling Extensible
Authentication Protocol Method (EAP-FAST)", RFC 4851,
May 2007.
[RFC5281] Funk, P. and S. Blake-Wilson, "Extensible Authentication
Protocol Tunneled Transport Layer Security Authenticated
Protocol Version 0 (EAP-TTLSv0)", RFC 5281, August 2008.
Author's Address
Sujing Zhou
ZTE Corporation
No.68 Zijinghua Rd. Yuhuatai District
Nanjing, Jiang Su 210012
R.R.China
Email: zhou.sujing@zte.com.cn
Zhou Expires January 7, 2013 [Page 5]
