Network Working Group Q. Wu, Ed. Internet-Draft Huawei Technologies Co., Ltd. Updates: 4072 (if approved) G. Zorn, Ed. Intended status: Standards Track Network Zen Expires: January 8, 2010 July 7, 2009 Diameter Attribute-Value Pairs for Cryptographic Key Transport draft-wu-dime-local-keytran-01 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on January 8, 2010. Copyright Notice Copyright (c) 2009 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract Some AAA applications require the transport of cryptographic keying material; this document specifies a set of Attribute-Value Pairs Wu & Zorn Expires January 8, 2010 [Page 1]
Internet-Draft Diameter Key Transport AVPs July 2009 (AVPs) providing native Diameter support of cryptographic key delivery. 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. EAP-Key AVP . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1.1. EAP-Key-Type AVP . . . . . . . . . . . . . . . . . . . 5 3.1.2. EAP-Key-Name AVP . . . . . . . . . . . . . . . . . . . 5 3.1.3. EAP-Keying-Material AVP . . . . . . . . . . . . . . . . 5 3.1.4. EAP-Key-Lifetime AVP . . . . . . . . . . . . . . . . . 6 4. AVP Occurrence Table . . . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 6.1. AVP Codes . . . . . . . . . . . . . . . . . . . . . . . . . 6 6.2. AVP Values . . . . . . . . . . . . . . . . . . . . . . . . 7 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7.1. Normative References . . . . . . . . . . . . . . . . . . . 7 7.2. Informative References . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Wu & Zorn Expires January 8, 2010 [Page 2]
Internet-Draft Diameter Key Transport AVPs July 2009 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 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 [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, 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 The following terms are used in this note. 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 AAA Authentication, Authorization, and Accounting (see below). Accounting The act of collecting information on resource usage for the purpose of trend analysis, auditing, billing, or cost allocation [RFC2989]. Authentication The act of verifying a claimed identity, in the form of a pre- existing label from a mutually known name space, as the originator of a message (message authentication) or as the end-point of a channel (entity authentication) [RFC2989]. Authorization The act of determining if a particular right, such as access to some resource, can be granted to the presenter of a particular credential [RFC2989]. Wu & Zorn Expires January 8, 2010 [Page 3]
Internet-Draft Diameter Key Transport AVPs July 2009 DER Diameter EAP request. [RFC4072] DEA Diameter EAP Answer. [RFC4072] DSRK Domain Specific Root Key [RFC5295]. EAP Extensible Authentication Protocol [RFC3748]. EMSK Extended Master Session Key [RFC3748]. ERP EAP Re-authentication Protocol [RFC5296]. MSK Master Session Key [RFC3748]. rMSK re-authentication MSK [RFC5296]. This is a per-authenticator key, derived from the rRK. rRK re-authentication Root Key, derived from the EMSK or DSRK [RFC5296]. USRK Usage Specific Root Key [RFC5295]. 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. EAP-Key AVP The EAP-Key AVP (AVP Code <AC1>) is of type Grouped [RFC3588]. It contains the name, type and optionally, the usable lifetime of the key, as well as the keying material itself. Wu & Zorn Expires January 8, 2010 [Page 4]
Internet-Draft Diameter Key Transport AVPs July 2009 EAP-Key ::= < AVP Header: AC1 > { EAP-Key-Type } { EAP-Keying-Material } [ EAP-Key-Lifetime ] [ EAP-Key-Name ] * [ AVP ] 3.1.1. EAP-Key-Type AVP The EAP-Key-Type AVP (AVP Code <AC2>) is of type Enumerated and signifies the type of the key being sent. The EAP-Key-Type MAY be included in a DER command as a signal that a certain type of key is required in the response (e.g., to support ERP). The following values are defined in this document: MSK (0) The EAP Master Session Key. [RFC3748] DSRK (1) A Domain Specific Root Key. [RFC5295] USRK (2) A Usage Specific Root Key. [RFC5295] rRK (4) A reauthentication Root Key. [RFC5296] rMSK (5) 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 6.2. 3.1.2. EAP-Key-Name AVP The syntax and semantics of the EAP-Key-Name AVP are specified in Section 4.1.4 of RFC 4072. 3.1.3. EAP-Keying-Material AVP The EAP-Keying-Material AVP (AVP Code <AC3>) is of type OctetString. The exact usage of this keying material depends upon several factors, including the link layer in use and the type of the key; it is beyond the scope of this document. Wu & Zorn Expires January 8, 2010 [Page 5]
Internet-Draft Diameter Key Transport AVPs July 2009 3.1.4. EAP-Key-Lifetime AVP The EAP-Key-Lifetime AVP (AVP Code <AC4>) is of type Integer64 [RFC3588] representing the period of time (in seconds) for which the keying material is valid. Note: Applications using this value SHOULD consider the beginning of the lifetime to be the point in time when the keying material is first used. 4. AVP Occurrence Table The following table lists the AVPs that MAY be present in the DER and DEA commands [RFC4072]. +---------------+ | Command-Code | +-+-----+-----+-+ AVP Name | DER | DEA | -------------------------------|-----+-----+ EAP-Key | 0 | 0+ | EAP-Key-Type | 0+ | 0 | EAP-Key-Name | 0-1 | 0-1 | +-----+-----+ DER and DEA Commands AVP Table 5. Security Considerations The security considerations discussed in [RFC3588] are applicable to this document. 6. IANA Considerations Upon publication of this memo as an RFC, IANA is requested to assign values as described in the following sections. 6.1. AVP Codes Codes must be assigned for the following AVPs using the policy specified in RFC 3588, Section 11.1.1: o EAP-Key (<AC1>, Section 3.1) Wu & Zorn Expires January 8, 2010 [Page 6]
Internet-Draft Diameter Key Transport AVPs July 2009 o EAP-Key-Type (<AC2>, Section 3.1.1) o EAP-Keying-Material (<AC3>, Section 3.1.3) o EAP-Key-Lifetime (<AC4>, Section 3.1.4) 6.2. AVP Values New values may be assigned for the EAP-Key-Type AVP (Section 3.1.1) using the "First Come, First Served" policy [RFC5226]. 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. Arkko, "Diameter Base Protocol", RFC 3588, September 2003. [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 [RFC2989] Aboba, B., Calhoun, P., Glass, S., Hiller, T., McCann, P., Shiino, H., Zorn, G., Dommety, G., C.Perkins, B.Patil, D.Mitton, S.Manning, M.Beadles, P.Walsh, X.Chen, S.Sivalingham, A.Hameed, M.Munson, S.Jacobs, B.Lim, B.Hirschman, R.Hsu, Y.Xu, E.Campell, S.Baba, and E.Jaques, "Criteria for Evaluating AAA Protocols for Network Access", RFC 2989, November 2000. [RFC5216] Simon, D., Aboba, B., and R. Hurst, "The EAP-TLS Authentication Protocol", RFC 5216, March 2008. [RFC5295] Salowey, J., Dondeti, L., Narayanan, V., and M. Nakhjiri, Wu & Zorn Expires January 8, 2010 [Page 7]
Internet-Draft Diameter Key Transport AVPs July 2009 "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 Qin Wu (editor) Huawei Technologies Co., Ltd. Site B, Floor 12F, Huihong Mansion, No.91 Baixia Rd. Nanjing, Jiangsu 21001 China Phone: +86-25-84565892 Email: sunseawq@huawei.com Glen Zorn (editor) Network Zen 1310 East Thomas Street #306 Seattle, Washington 98102 USA Phone: +1 (206) 377-9035 Email: gwz@net-zen.net Wu & Zorn Expires January 8, 2010 [Page 8]