EAP Session-Id Derivation for EAP-SIM, EAP-AKA, and PEAP
draft-ietf-emu-eap-session-id-04
The information below is for an old version of the document.
| Document | Type | Active Internet-Draft (emu WG) | |
|---|---|---|---|
| Author | Alan DeKok | ||
| Last updated | 2020-06-11 (Latest revision 2020-05-27) | ||
| Replaces | draft-dekok-emu-eap-session-id | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text htmlized pdfized bibtex | ||
| Reviews |
GENART Last Call review
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| Stream | WG state | Submitted to IESG for Publication | |
| Associated WG milestone |
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||
| Document shepherd | Mohit Sethi | ||
| Shepherd write-up | Show Last changed 2020-01-08 | ||
| IESG | IESG state | IESG Evaluation::Revised I-D Needed | |
| Consensus boilerplate | Yes | ||
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Needs 2 more YES or NO OBJECTION positions to pass. |
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| Responsible AD | Roman Danyliw | ||
| Send notices to | Mohit Sethi <mohit.m.sethi@ericsson.com> | ||
| IANA | IANA review state | IANA OK - No Actions Needed |
draft-ietf-emu-eap-session-id-04
Network Working Group DeKok, Alan
INTERNET-DRAFT FreeRADIUS
Updates: 5247 (if approved) 27 May 2020
Intended status: Standards Track
Expires: November 27, 2020
EAP Session-Id Derivation for EAP-SIM, EAP-AKA, and PEAP
draft-ietf-emu-eap-session-id-04.txt
Abstract
EAP Session-Id derivation has not been defined for EAP-SIM or EAP-AKA
when using the fast re-authentication exchange instead of full
authentication. This document updates RFC 5247 to define those
derivations for EAP-SIM and EAP-AKA. RFC 5247 also does not define
Session-Id derivation for PEAP. A definition is given here which
follows the definition for other TLS-based EAP methods.
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-
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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 November 27, 2020.
Copyright Notice
Copyright (c) 2020 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
DeKok, Alan Proposed Standard [Page 1]
INTERNET-DRAFT EAP Session-ID Derivation 27 May 2020
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.
DeKok, Alan Proposed Standard [Page 2]
INTERNET-DRAFT EAP Session-ID Derivation 27 May 2020
Table of Contents
1. Introduction ............................................. 4
1.1. Requirements Language ............................... 4
2. Updates to RFC 5247 Appendix A ........................... 5
2.1. EAP-AKA ............................................. 5
2.2. EAP-SIM ............................................. 5
2.3. Rationale for EAP-AKA and EAP-SIM updates ........... 7
3. Session-Id for PEAP ...................................... 7
4. Security Considerations .................................. 7
5. IANA Considerations ...................................... 8
6. References ............................................... 8
6.1. Normative References ................................ 8
6.2. Informative References .............................. 9
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1. Introduction
EAP [RFC3748] Session-Id derivation has not been defined for EAP-SIM
and EAP-AKA when using the fast re-authentication exchange instead of
full authentication. [RFC5247] defines the Session-Id for these EAP
methods, but that derivation is only applicable for the full
authentication case. The Session-Id derivation was not defined for
EAP-AKA', but [AKAP] now defines it, along with other updates. As
such, the definition for EAP-AKA' is not included here.
The IEEE is defining FILS authentication [FILS], which needs the EAP
Session-Id in order for the EAP Re-authentication Protocol (ERP)
[RFC6696] to work. It is therefore important to address the existing
deficiencies in the definition of EAP Session-Id.
Further, [RFC5247] did not define Session-Id for PEAP. We correct
these deficiencies here by updating [RFC5247] with the Session-Id
derivation during fast-authentication exchange for EAP-SIM and EAP-
AKA; and defining Session-Id derivation for PEAP.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
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2. Updates to RFC 5247 Appendix A
This section updates [RFC5247] Appendix A to define Session-Id for
fast re-authentication exchange for EAP-AKA and EAP-SIM. It further
defines Session-ID derivation for PEAP.
2.1. EAP-AKA
For EAP-AKA, [RFC5247] Appendix A says:
EAP-AKA
EAP-AKA is defined in [RFC4187]. The EAP-AKA Session-Id is the
concatenation of the EAP Type Code (0x17) with the contents of the
RAND field from the AT_RAND attribute, followed by the contents of
the AUTN field in the AT_AUTN attribute:
Session-Id = 0x17 || RAND || AUTN
It should say:
EAP-AKA
EAP-AKA is defined in [RFC4187]. When using full authentication,
the EAP-AKA Session-Id is the concatenation of the EAP Type Code
(0x17) with the contents of the RAND field from the AT_RAND
attribute, followed by the contents of the AUTN field in the
AT_AUTN attribute:
Session-Id = 0x17 || RAND || AUTN
When using fast re-authentication, the EAP-AKA Session-Id is the
concatenation of the EAP Type Code (0x17) with the contents of the
NONCE_S field from the AT_NONCE_S attribute, followed by the
contents of the MAC field from the AT_MAC attribute from EAP-
Request/AKA-Reauthentication:
Session-Id = 0x17 || NONCE_S || MAC
2.2. EAP-SIM
Similarly for EAP-SIM, [RFC5247] Appendix A says:
EAP-SIM
EAP-SIM is defined in [RFC4186]. The EAP-SIM Session-Id is the
concatenation of the EAP Type Code (0x12) with the contents of the
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RAND field from the AT_RAND attribute, followed by the contents of
the NONCE_MT field in the AT_NONCE_MT attribute:
Session-Id = 0x12 || RAND || NONCE_MT
The Peer-Id is the contents of the Identity field from the
AT_IDENTITY attribute, using only the Actual Identity Length
octets from the beginning, however. Note that the contents are
used as they are transmitted, regardless of whether the
transmitted identity was a permanent, pseudonym, or fast EAP re-
authentication identity. The Server-Id is the null string (zero
length).
It should say:
EAP-SIM
EAP-SIM is defined in [RFC4186]. When using full authentication,
the EAP-SIM Session-Id is the concatenation of the EAP Type Code
(0x12) with the contents of the RAND field from the AT_RAND
attribute, followed by the contents of the NONCE_MT field in the
AT_NONCE_MT attribute. RFC 4186 says that EAP server should
obtain "n" GSM triplets where "n=2" or "n=3".
For "n=2", the Session-Id is therefore defined as
Session-Id = 0x12 || RAND1 || RAND2 || NONCE_MT
which is 49 octets in length.
For "n=3", the Session-Id is therefore defined as
Session-Id = 0x12 || RAND1 || RAND2 || RAND3 || NONCE_MT
which is 65 octets in length.
Where RAND1, RAND2 and RAND3 correspond to the RAND value from the
first, second and third GSM triplet respectively.
The Peer-Id is the contents of the Identity field from the
AT_IDENTITY attribute, using only the Actual Identity Length
octets from the beginning, however. Note that the contents are
used as they are transmitted, regardless of whether the
transmitted identity was a permanent, pseudonym, or fast EAP re-
authentication identity. The Server-Id is the null string (zero
length).
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When using fast re-authentication, the EAP-SIM Session-Id is the
concatenation of the EAP Type Code (0x12) with the contents of the
NONCE_S field from the AT_NONCE_S attribute, followed by the
contents of the MAC field from the AT_MAC attribute from EAP-
Request/AKA-Reauthentication:
Session-Id = 0x12 || NONCE_S || MAC
which is 33 octets in length.
2.3. Rationale for EAP-AKA and EAP-SIM updates
[RFC5247] was supposed to define exported parameters for existing EAP
methods in Appendix A. The way Session-Id was defined for EAP-AKA and
EAP-SIM works only for the full authentication case, i.e., it cannot
be used when the optional fast re-authentication case is used since
the used parameters (RAND, AUTN, NONCE_MT) are not used in the fast
re-authentication case. Based on [RFC4187] Section 5.2, and similar
text in [RFC4186], NONCE_S corresponds to RAND and MAC in EAP-
Request/AKA-Reauthentication corresponds to AUTN. That would seem to
imply that the Session-Id could be defined using NONCE_S and MAC
instead of RAND and AUTN/NONCE_MT.
3. Session-Id for PEAP
[RFC5247] did not define Session-Id definition for Microsoft's
Protected EAP (PEAP). For consistency with EAP-TLS the definition
given in [RFC5216] Section 2.3, we define it as:
Session-Id = 0x19 || client.random || server.random
This definition is already in wide-spread use in multiple PEAP
implementations.
Note that this definition for Session-Id only applies when TLS 1.2 is
used. A different derivation is defined for TLS 1.3 in [TLS-EAP-
TYPES].
4. Security Considerations
This specification defines EAP Session-Ids for ERP with EAP-SIM and
EAP-AKA. It therefore enables ERP key hierarchy establishment using
fast re-authentication with EAP-SIM and EAP-AKA.
There are no known security issues from using the NONCE_S and MAC as
defined above.
This specification also defines the EAP Session-Id for PEAP. That
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derivation has no known security issues.
These updates do not modify the Security Considerations outlined in
RFC5247.
5. IANA Considerations
There are no actions for IANA. RFC EDITOR: This section may be
removed before publication.
6. References
6.1. Normative References
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", RFC 2119, March, 1997, <http://www.rfc-
editor.org/info/rfc2119>.
[RFC3748]
Aboba, B., Blunk, L., Vollbrecht, J., Carlson, J., and H.
Levkowetz, "Extensible Authentication Protocol (EAP)", RFC 3748,
June 2004.
[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,
[RFC6696]
Cao, Z. et al, "EAP Extensions for EAP Re-authentication Protocol
(ERP)", RFC 6696, July 2012.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key
Words", RFC 8174, May 2017, <http://www.rfc-
editor.org/info/rfc8174>.
[FILS]
"IEEE Standard for 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 -
Amendment 1: Fast Initial Link Setup", IEEE Std 802.11ai-2016,
2016.
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6.2. Informative References
[RFC4186]
Haverinen, H. (Ed), Salowey, J., "Extensible Authentication
Protocol Method for Global System for Mobile Communications (GSM)
Subscriber Identity Modules (EAP-SIM)", RFC 4186, January 2006.
[RFC4187]
Arkko, J., Haverinen, H., "Extensible Authentication Protocol
Method for 3rd Generation Authentication and Key Agreement (EAP-
AKA)", RFC 4187, January 2006.
[AKAP]
Arkko, J., et al, "Improved Extensible Authentication Protocol
Method for 3rd Generation Authentication and Key Agreement (EAP-
AKA')", draft-ietf-emu-rfc5448bis-07.txt, March 2020.
[TLS-EAP-TYPES]
DeKok, A., "TLS-based EAP types and TLS 1.3" draft-dekok-emu-tls-
eap-types-02, April, 2020.
Acknowledgments
The issue corrected in this specification was first reported by Jouni
Malinen in a technical errata at https://www.rfc-
editor.org/errata_search.php?rfc=5247
The text in this document follows Jouni's suggestions.
Authors' Addresses
Alan DeKok
The FreeRADIUS Server Project
Email: aland@freeradius.org
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