Network Working Group G. Zorn Internet-Draft Network Zen Intended status: Standards Track Q. Wu Expires: July 28, 2012 Huawei January 25, 2012 A Lightweight Approach to Node-to-Node Security in Diameter draft-zorn-dime-n2n-sec-lite-02 Abstract This document describes a lightweight method for cryptographically protecting a portion of the contents of a Diameter message in transit between an arbitrary pair of Diameter nodes. The scheme assumes that the destination node possesses an X.509 certificate containing an RSA public key and that that certificate is retrievable through a DNS query by the node originating the message. In addition to describing the operation of the protocol, this note specifies an Attribute-Value Pair (AVP) for the encapsulation of encrypted AVPs. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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This document is subject to BCP 78 and the IETF Trust's Legal Zorn & Wu Expires July 28, 2012 [Page 1] Internet-Draft Node-to-Node Security in Diameter January 2012 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Protocol Operation . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Client Operation . . . . . . . . . . . . . . . . . . . . . 3 3.1.1. Key Establishment . . . . . . . . . . . . . . . . . . . 3 3.1.2. Protected Data Transfer . . . . . . . . . . . . . . . . 3 3.2. Server Operation . . . . . . . . . . . . . . . . . . . . . 3 3.2.1. Key Establishment . . . . . . . . . . . . . . . . . . . 3 3.2.2. Protected Data Transfer . . . . . . . . . . . . . . . . 4 4. Attribute-Value Pair Definitions . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7.1. Normative References . . . . . . . . . . . . . . . . . . . 4 7.2. Informative References . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Zorn & Wu Expires July 28, 2012 [Page 2] Internet-Draft Node-to-Node Security in Diameter January 2012 1. Introduction Historically, Authentication, Authorization and Accounting (AAA) network traffic has been secured on a hop-by-hop basis: messages between AAA entities (such as Diameter clients, agents and servers) have been protected on the wire but those entities have had unfettered access to the message contents. This has not typically been considered to be a concern when all of the entities in question were within the same sphere of administrative control, but may be problematic if the messages pass through an outside system (for example, an agent residing in an intermediate domain in a roaming situation). This document describes a lightweight method for cryptographically protecting a portion of the contents of a Diameter message while in transit between an arbitrary pair of Diameter nodes. 2. 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 RFC 2119 [RFC2119]. 3. Protocol Operation The following sections describe the operation of the proposed end-to- end security scheme. Although key establishment and data transfer are discussed separately, both will usually take place in the same message. 3.1. Client Operation 3.1.1. Key Establishment TBC. 3.1.2. Protected Data Transfer TBC. 3.2. Server Operation 3.2.1. Key Establishment TBC. Zorn & Wu Expires July 28, 2012 [Page 3] Internet-Draft Node-to-Node Security in Diameter January 2012 3.2.2. Protected Data Transfer TBC. 4. Attribute-Value Pair Definitions This section defines a container AVP for the transport of encrypted AVPs in Diameter applications. 5. Security Considerations The security considerations applicable to the Diameter Base Protocol [RFC3588] are also applicable to this document. 6. IANA Considerations TBC. 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. [RFC4398] Josefsson, S., "Storing Certificates in the Domain Name System (DNS)", RFC 4398, March 2006. [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. Zorn & Wu Expires July 28, 2012 [Page 4] Internet-Draft Node-to-Node Security in Diameter January 2012 7.2. Informative References [I-D.ietf-smime-cms-rsa-kem] Brainard, J., Turner, S., Randall, J., and B. Kaliski, "Use of the RSA-KEM Key Transport Algorithm in CMS", draft-ietf-smime-cms-rsa-kem-13 (work in progress), May 2010. [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 Qin Wu Huawei Technologies Co., Ltd. 101 Software Avenue, Yuhua District Nanjing, Jiangsu 21001 China Phone: +86-25-84565892 Email: sunseawq@huawei.com Zorn & Wu Expires July 28, 2012 [Page 5]