Internet DRAFT - draft-ietf-dime-local-keytran
draft-ietf-dime-local-keytran
Network Working Group G. Zorn
Internet-Draft Network Zen
Intended status: Standards Track Q. Wu
Expires: February 20, 2012 Huawei
V. Cakulev
Alcatel Lucent
August 19, 2011
Diameter Attribute-Value Pairs for Cryptographic Key Transport
draft-ietf-dime-local-keytran-14
Abstract
Some Authentication, Authorization, and Accounting (AAA) applications
require the transport of cryptographic keying material. This
document specifies a set of Attribute-Value Pairs (AVPs) providing
native Diameter support of cryptographic key delivery.
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
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This Internet-Draft will expire on February 20, 2012.
Copyright Notice
Copyright (c) 2011 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
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to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 3
2.2. Technical Terms and Acronyms . . . . . . . . . . . . . . . 3
3. Attribute-Value Pair Definitions . . . . . . . . . . . . . . . 4
3.1. Key AVP . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1.1. Key-Type AVP . . . . . . . . . . . . . . . . . . . . . 4
3.1.2. Key-Name AVP . . . . . . . . . . . . . . . . . . . . . 4
3.1.3. Keying-Material AVP . . . . . . . . . . . . . . . . . . 5
3.1.4. Key-Lifetime AVP . . . . . . . . . . . . . . . . . . . 5
3.1.5. Key-SPI . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
5.1. AVP Codes . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2. AVP Values . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7
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1. Introduction
The Diameter EAP application [RFC4072] defines the EAP-Master-
Session-Key and EAP-Key-Name AVPs for the purpose of transporting
cryptographic keying material derived during the execution of certain
Extensible Authentication Protocol (EAP) [RFC3748] methods (for
example, EAP-TLS [RFC5216]). At most one instance of either of these
AVPs is allowed in any Diameter message.
However, recent work (see, for example, [RFC5295]) has specified
methods to derive other keys from the keying material created during
EAP method execution that may require transport in addition to the
MSK. In addition, the EAP Re-authentication Protocol (ERP) [RFC5296]
specifies new keys that may need to be transported between Diameter
nodes.
This note specifies a set of AVPs allowing the transport of multiple
cryptographic keys in a single Diameter message.
2. Terminology
2.1. Standards Language
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 RFC 2119 [RFC2119].
2.2. Technical Terms and Acronyms
DSRK
Domain-Specific Root Key [RFC5295].
MSK
Master Session Key [RFC3748].
rMSK
reauthentication MSK [RFC5296]. This is a per-authenticator key,
derived from the rRK (below).
rRK
reauthentication Root Key, derived from the EMSK Extended Master
Session Key [RFC3748] or DSRK [RFC5296].
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3. Attribute-Value Pair Definitions
This section defines new AVPs for the transport of cryptographic keys
in the Diameter EAP application [RFC4072], as well as other Diameter
applications.
3.1. Key AVP
The Key AVP (AVP Code <AC1>) is of type Grouped. It contains the
type and keying material and, optionally, an indication of the usable
lifetime of the key, the name of the key and a Security Parameter
Index (SPI) with which the key is associated.
Key ::= < AVP Header: AC1 >
< Key-Type >
{ Keying-Material }
[ Key-Lifetime ]
[ Key-Name ]
[ Key-SPI ]
* [ AVP ]
3.1.1. Key-Type AVP
The Key-Type AVP (AVP Code <AC2>) is of type Enumerated. This AVP
identifies the type of the key being sent. The following decimal
values are defined in this document:
DSRK (0)
A Domain-Specific Root Key [RFC5295].
rRK (1)
A reauthentication Root Key [RFC5296].
rMSK (2)
A reauthentication Master Session Key [RFC5296].
If additional values are needed, they are to be assigned by IANA
according to the policy stated in Section 5.2,
3.1.2. Key-Name AVP
The Key-Name AVP (AVP Code <AC6>) is of type OctetString. It
contains an opaque key identifier. Exactly how this name is
generated and used depends on the key type and usage in question, and
is beyond the scope of this document (see [RFC5247] and [RFC5295] for
discussions of key name generation in the context of EAP).
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3.1.3. Keying-Material AVP
The Keying-Material AVP (AVP Code <AC3>) is of type OctetString. The
exact usage of this keying material depends upon several factors,
including the type of the key and the link layer in use and is beyond
the scope of this document.
3.1.4. Key-Lifetime AVP
The Key-Lifetime AVP (AVP Code <AC4>) is of type Unsigned32 and
represents the period of time (in seconds) for which the contents of
the Keying-Material AVP (Section 3.1.3) is valid.
NOTE:
Applications using this value SHOULD consider the beginning of the
lifetime to be the point in time when the message containing the
keying material is received. In addition, client implementations
SHOULD check to ensure that the value is reasonable; for example,
the lifetime of a key should not generally be longer than the
session lifetime (see section 8.13 of [I-D.ietf-dime-rfc3588bis].
3.1.5. Key-SPI
The Key-SPI AVP (AVP Code <AC5>) is of type Unsigned32 and contains a
SPI value that can be used with other parameters for identifying
associated keying material.
4. Security Considerations
Transporting keys is a security-sensitive action. Some forms of
keying material are already protected and can be sent safely over the
open Internet. However, if a Key AVP contains Keying-Material that
is not already protected, then the Diameter messages containing that
Key AVP MUST only be sent protected via mutually authenticated TLS or
IPsec.
The security considerations applicable to the Diameter Base Protocol
[I-D.ietf-dime-rfc3588bis] are also applicable to this document, as
are those in Section 8.4 of RFC 4072 [RFC4072].
5. IANA Considerations
Upon publication of this memo as an RFC, IANA is requested to assign
values as described in the following sections.
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5.1. AVP Codes
Codes must be assigned for the following AVPs using the policy
specified in [I-D.ietf-dime-rfc3588bis], Section 11.1.1:
o Key (<AC1>, Section 3.1)
o Key-Type (<AC2>, Section 3.1.1)
o Keying-Material (<AC3>, Section 3.1.3)
o Key-Lifetime (<AC4>, Section 3.1.4)
o Key-SPI (<AC5>, Section 3.1.5)
o Key-Name (<AC6>, Section 3.1.2)
5.2. AVP Values
IANA is requested to create a new registry for values assigned to the
Key-Type AVP and populated with the decimal values defined in this
document (Section 3.1.1). New values may be assigned for the Key-
Type AVP using the "Specification Required" policy [RFC5226]; once
values have been assigned, they MUST NOT be deleted, replaced or
modified.
6. Acknowledgements
Thanks (in no particular order) to Niclas Comstedt, Semyon
Mizikovsky, Hannes Tschofenig, Joe Salowey, Tom Taylor, Frank Xia,
Lionel Morand, Dan Romascanu, Bernard Aboba, Jouni Korhonen, Stephen
Farrel, Joel Halpern, Phillip Hallam-Baker, Sean Turner and Sebastien
Decugis for useful comments, suggestions and review.
7. References
7.1. Normative References
[I-D.ietf-dime-rfc3588bis]
Fajardo, V., Arkko, J., Loughney, J., and G. Zorn,
"Diameter Base Protocol", draft-ietf-dime-rfc3588bis-26
(work in progress), January 2011.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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[RFC3748] Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H.
Levkowetz, "Extensible Authentication Protocol (EAP)",
RFC 3748, June 2004.
[RFC4072] Eronen, P., Hiller, T., and G. Zorn, "Diameter Extensible
Authentication Protocol (EAP) Application", RFC 4072,
August 2005.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
7.2. Informative References
[RFC5216] Simon, D., Aboba, B., and R. Hurst, "The EAP-TLS
Authentication Protocol", RFC 5216, March 2008.
[RFC5247] Aboba, B., Simon, D., and P. Eronen, "Extensible
Authentication Protocol (EAP) Key Management Framework",
RFC 5247, August 2008.
[RFC5295] Salowey, J., Dondeti, L., Narayanan, V., and M. Nakhjiri,
"Specification for the Derivation of Root Keys from an
Extended Master Session Key (EMSK)", RFC 5295,
August 2008.
[RFC5296] Narayanan, V. and L. Dondeti, "EAP Extensions for EAP Re-
authentication Protocol (ERP)", RFC 5296, August 2008.
Authors' Addresses
Glen Zorn
Network Zen
227/358 Thanon Sanphawut
Bang Na, Bangkok 10260
Thailand
Phone: +66 (0) 87-040-4617
Email: glenzorn@gmail.com
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Qin Wu
Huawei Technologies Co., Ltd.
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 21001
China
Phone: +86-25-56623633
Email: sunseawq@huawei.com
Violeta Cakulev
Alcatel Lucent
600 Mountain Ave.
3D-517
Murray Hill, NJ 07974
US
Phone: +1 908 582 3207
Email: violeta.cakulev@alcatel-lucent.com
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