Network Working Group Dorothy Stanley INTERNET-DRAFT Agere Category: Informational Jesse Walker <draft-walker-ieee802-req-00.txt> Intel Corporation 3 February 2004 Bernard Aboba Microsoft Corporation EAP Method Requirements for Wireless LANs This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC 2026. 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. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract The Draft IEEE 802.11i MAC Security Enhancements Amendment makes use of IEEE 802.1X which in turn relies on the Extensible Authentication Protocol (EAP). This document defines requirements for EAP methods used in IEEE 802.11 wireless LAN deployments. The material in this document has been approved by IEEE 802.11 and it is being presented as an IETF RFC for informational purposes. Stanley, et al. Informational [Page 1]
INTERNET-DRAFT EAP Method Reqts. for WLAN 3 February 2004 1. Introduction The Draft IEEE 802.11i MAC Security Enhancements Amendment [IEEE802.11i] makes use of IEEE 802.1X [IEEE8021X-REV] which in turn relies on the Extensible Authentication Protocol (EAP), defined in [RFC2284bis]. Deployments of IEEE 802.11 wireless LANs today are based on EAP, and use several EAP methods, including EAP-TLS [RFC2716], EAP-TTLS [TTLS], PEAP [PEAP] and EAP-SIM [SIM]. These methods support authentication credentials that include digital certificates, user-names and passwords, secure tokens, and SIM secrets. This document defines requirements for EAP methods used in IEEE 802.11 wireless LAN deployments. 1.1. Requirements specification In this document, several words are used to signify the requirements of the specification. These words are often capitalized. 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]. An EAP authentication method is not compliant with this specification if it fails to satisfy one or more of the MUST or MUST NOT requirements. An EAP authentication method that satisfies all the MUST, MUST NOT, SHOULD and SHOULD NOT requirements is said to be "unconditionally compliant"; one that satisfies all the MUST and MUST NOT requirements but not all the SHOULD or SHOULD NOT requirements is said to be "conditionally compliant". 2. Method requirements 2.1. Credential types The Draft IEEE 802.11i MAC Security Enhancements Amendment requires that EAP authentication methods are available. Wireless LAN deployments are expected to use different credentials types, including digital certificates, user-names and passwords, existing secure tokens, and mobile network credentials (GSM and UMTS secrets). Other credential types that may be used include public/private key (without necessarily requiring certificates), and asymmetric credential support (password on one side, public/private key on the other). 2.2. Mandatory requirements EAP authentication methods suitable for use in wireless LAN authentication MUST satisfy the following criteria: Stanley, et al. Informational [Page 2]
INTERNET-DRAFT EAP Method Reqts. for WLAN 3 February 2004 [1] Generation of keying material. This corresponds to the "Key derivation" security claim defined in [RFC2284bis], Section 7.2.1. [2] Mutual authentication support. This corresponds to the "Mutual authentication" security claim defined in [RFC2284bis], Section 7.2.1. [3] Synchronization of state. This corresponds to the "Protected result indication" security claim defined in [RFC2284bis], Section 7.2.1. [4] Resistance to dictionary attacks. This corresponds to the "Dictionary attack resistance" security claim defined in [RFC2284bis], Section 7.2.1. [5] Protection against man-in-the-middle attacks. This corresponds to the "Cryptographic binding", "Integrity Protection", "Replay protection", and "Session Independence" security claims defined in [RFC2284bis], Section 7.2.1. [6] Protected ciphersuite negotiation. If the method negotiates the ciphersuite used to protect the EAP conversation, then it MUST support the "Protected ciphersuite negotiation" security claim defined in [RFC2284bis], Section 7.2.1. [7] Key strength. An EAP method suitable for use with IEEE 802.11 MUST be capable of generating keying material with 128-bits of effective key strength, as defined in [RFC2284bis] Section 7.2.1. As noted in [RFC2284bis] Section 7.10, an EAP method supporting key derivation MUST export a Master Session Key (MSK) of at least 64 octets, and an Extended Master Session Key (EMSK) of at least 64 octets. 2.3. Recommended requirements EAP authentication methods used for wireless LAN authentication SHOULD support the following features: [8] Fragmentation. [RFC2284bis] Section 3.1 states: "EAP methods can assume a minimum EAP MTU of 1020 octets, in the absence of other information. EAP methods SHOULD include support for fragmentation and reassembly if their payloads can be larger than this minimum EAP MTU." This implies support for the "Fragmentation" claim defined in [RFC2284bis], Section 7.2.1. Stanley, et al. Informational [Page 3]
INTERNET-DRAFT EAP Method Reqts. for WLAN 3 February 2004 2.4. Optional features EAP authentication methods used for wireless LAN authentication MAY support the following features: [9] Channel binding. This corresponds to the "Channel binding" security claim defined in [RFC2284bis], Section 7.2.1. [10] End-user identity hiding. This corresponds to the "Confidentiality" security claim defined in [RFC2284bis], Section 7.2.1. [11] Fast reconnect. This corresponds to the "Fast reconnect" security claim defined in [RFC2284bis], Section 7.2.1. 2.5. Non-compliant EAP authentication methods EAP-MD5-Challenge (the current mandatory-to-implement EAP authentication method), is defined in [RFC2284bis] Section 5.4. EAP-MD5-Challenge and two EAP authentication methods defined in [RFC2284bis], One-Time Password (Section 5.5) and Generic Token Card (Section 5.6), are non- compliant with the requirements defined in this document. 3. References 3.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March, 1997. [RFC2284bis] Blunk, L. , et al., "Extensible Authentication Protocol (EAP)", draft-ietf-eap-rfc2284bis-08.txt, Internet-Draft (work in progress), February 2004. 3.2. Informative References [RFC2716] Aboba, B. and D. Simon, "PPP EAP TLS Authentication Protocol", RFC 2716, October 1999. [PEAP] Palekar, A., et al., "Protected EAP Protocol (PEAP)", draft-josefsson-pppext-eap-tls-eap-07.txt, Internet draft (work in progress), November 2003. [TTLS] Funk, P. and S. Blake-Wilson, "EAP Tunneled TLS Authentication Protocol (EAP-TTLS)", draft-ietf-pppext- eap-ttls-03.txt, August 2003. Stanley, et al. Informational [Page 4]
INTERNET-DRAFT EAP Method Reqts. for WLAN 3 February 2004 [EAPSIM] Haverinen, H. and J. Salowey, "EAP SIM Authentication", draft-haverinen-pppext-eap-sim-12.txt, Internet draft (work in progress), October 2003. [IEEE802] IEEE Standards for Local and Metropolitan Area Networks: Overview and Architecture, ANSI/IEEE Std 802, 1990. [802.11] Information technology - Telecommunications and information exchange between systems - Local and metropolitan area networks - Specific Requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, IEEE Std. 802.11-1999, 1999. [IEEE8021X-REV] IEEE Standards for Local and Metropolitan Area Networks: Port based Network Access Control, IEEE Std 802.1X-REV, Draft 8, December 2003. [IEEE802.11i] Institute of Electrical and Electronics Engineers, "Unapproved Draft Supplement to Standard for Telecommunications and Information Exchange Between Systems - LAN/MAN Specific Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: Specification for Enhanced Security", IEEE Draft 802.11i (work in progress), 2003. Acknowledgments The authors would like to acknowledge members of the IEEE 802.11i task group, including David Nelson of Enterasys Networks and Clint Chaplin of Symbol Technologies for contributions to this document. Authors' Addresses Dorothy Stanley Agere Systems 2000 North Naperville Rd. Naperville, IL 60566 EMail: dstanley@agere.com Phone: +1 630 979 1572 Jesse R. Walker Intel Corporation 2111 N.E. 25th Avenue Hillsboro, OR 97214 Stanley, et al. Informational [Page 5]
INTERNET-DRAFT EAP Method Reqts. for WLAN 3 February 2004 EMail: jesse.walker@intel.com Bernard Aboba Microsoft Corporation One Microsoft Way Redmond, WA 98052 EMail: bernarda@microsoft.com Phone: +1 425 706 6605 Fax: +1 425 936 7329 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards- related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director. Full Copyright Statement Copyright (C) The Internet Society (2004). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are Stanley, et al. Informational [Page 6]
INTERNET-DRAFT EAP Method Reqts. for WLAN 3 February 2004 perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Expiration Date This memo is filed as <draft-walker-ieee802-req-00.txt>, and expires August 22, 2004. Stanley, et al. Informational [Page 7]
