IPv6 Maintenance J. Korhonen Internet-Draft Broadcom Intended status: Standards Track S. Krishnan Expires: April 24, 2014 Ericsson October 21, 2013 Support for multiple provisioning domains in IPv6 Neighbor Discovery Protocol draft-kk-mpvd-ndp-support-00 Abstract The MIF working group is producing a solution to solve the issues that are associated with nodes that can be attached to multiple networks. One part of the solution requires associating configuration information with provisioning domains. This document details how configuration information provided through IPv6 Neighbor Discovery Protocol can be associated with provisioning domains. 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 working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on April 24, 2014. Copyright Notice Copyright (c) 2013 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 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 Korhonen & Krishnan Expires April 24, 2014 [Page 1] Internet-Draft NDP PVD support October 2013 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. PVD Container option . . . . . . . . . . . . . . . . . . . . . 3 4. PVD Identity option . . . . . . . . . . . . . . . . . . . . . . 6 5. Set of allowable options . . . . . . . . . . . . . . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 9.1. Normative References . . . . . . . . . . . . . . . . . . . 8 9.2. Informative References . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 Korhonen & Krishnan Expires April 24, 2014 [Page 2] Internet-Draft NDP PVD support October 2013 1. Introduction The MIF working group is producing a solution to solve the issues that are associated with nodes that can be attached to multiple networks based on the Multiple Provisioning Domains (MPVD) architecture work [I-D.anipko-mif-mpvd-arch]. One part of the solution requires associating configuration information with Provisioning Domains (PVD). This document describes an IPv6 Neighbor Discovery Protocol (NDP) [RFC4861] mechanism for explicitly indicating provisioning domain information along with any configuration that will be provided. The proposed mechanism uses an NDP option that indicates the identity of the provisioning domain and encapsulates the options that contain the configuration information as well as any accompanying authentication/authorization information. The solution defined in this document aligns as much as possible with the existing IPv6 Neighbor Discovery security, namely with Secure Neighbor Discovery (SeND) [RFC3971]. 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 [RFC2119]. 3. PVD Container option The PVD container option (PVD_CO) is used to encapsulate and group together all the configuration options that belong to the explicitly identified provisioning domain. The PVD container option MUST encapsulate exactly one PVD identifier option (PVD_ID). The PVD container option MAY occur multiple times in the same NDP message but each of these PVD container options MUST have a different PVD identity specified under its PVD identity option. A PVD container is intended to be used in IPv6 Router Advertisement (RA) NDP messages. However, including a PVD container inside a Router Solicitation (RS) NDP messages is also possible (actually, a host can in this way solicit for information from a specific PVD). For the backward compatibility and the reuse of existing NDP options, the PVD container can encapsulate any (meaningful) existing IPv6 NDP options. For example, the PVD container could encapsulate a Prefix Information Option (PIO), which would mark that a certain advertised IPv6 prefix belongs and originates from a specific PVD. Furthermore, for the backward compatibility reasons, it is RECOMMENDED that options critical for establishing IP communication (such as the prefix and DNS information) are encapsulated inside the PVD container Korhonen & Krishnan Expires April 24, 2014 [Page 3] Internet-Draft NDP PVD support October 2013 as well as in the RA (although this will cause duplication of information is most cases). This ensures hosts that do not understand provisioning domain concept, will at least receive the implicit provisioning domain configuration. Hosts that understand provisioning domain SHOULD always give configuration information encapsulated inside the PVD container a higher priority than the ones outside the PVD container(s). It should be noted that a router can do smart advertisement of "legacy" configuration information and the PVD container encapsulated. The router MAY leave some of the provisioning domain specific information outside the "legacy [RFC4861] way" of advertising them in RAs. The optional security for the PVD container is based on X.509 certificates [RFC6487] and reuses mechanisms already defined for SeND [RFC3971] [RFC6495]. However, the use of PVD containers does not assume or depend on SeND being deployed or even implemented. The PVD containers SHOULD be signed per PVD certificates, which provides both integrity protection and proves that the configuration information source is authorized for advertising the given information. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=PVD_CO | Length | Options Count | Name Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ : : : Suboptions (padded to 8 octet boundary) : : : +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <+ : : | : Key Hash : o : : p +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ t : : i : Digital Signature : o : : n +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ a : Padding (zeroes) : l +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ <+ Figure 1: PVD Container Option Type PVD Container; Set to TBA1. Korhonen & Krishnan Expires April 24, 2014 [Page 4] Internet-Draft NDP PVD support October 2013 Length Length of the PVD_CO. The actual length depends on the number of suboptions and the optional Key Hash/Digital Signature/Padding. Options Count The number of suboptions in this PVD container. MUST be 1 or greater. Name Type Names the algorithm used to identify a specific X.509 certificate using the method defined for the Subject Key Identifier (SKI) extension for the X.509 certificates. The usage and the Name Type registry aligns with the mechanism defined for SeND [RFC6494][RFC6495]. Name Type values starting from 3 are supported and an implementation MUST at least support SHA-1 (value 3). Suboptions One or more suboptions that describe properties and other meta data attached to the provisioning domain. See Section 4 for description of the PVD_ID suboption. All suboptions MUST be multiple of 8 octets and provide required padding with '\0' octets, when needed. Unknown suboptions MUST be silently discarded. Key Hash A hash of the public key using the algorithm identified by the Name Type. The procedure how the Key Hash is calculated is defined in [RFC3971] and [RFC6495]. Digital Signature A signature calculated over the PVD_CO option including all option data from the beginning of the option until the Key Hash field. The procedure of calculating the signature is identical to the one defined for SeND [RFC3971]. Padding Zero or more '\0' octets to make the PVD_CO to multiple of 8 octets. The presence of the optional Key Hash and Digital Signature field is Korhonen & Krishnan Expires April 24, 2014 [Page 5] Internet-Draft NDP PVD support October 2013 determined from the Length field, i.e. the option length is greater than 0 after subtracting 'Options Count' times suboptions from it, then the signature part of the option is present. If the PVD_CO does not contain a digital signature, then other means to secure the integrity of the NDP message SHOULD be provided, such as utilizing SeND. However, the security provided by SeND is for the entire NDP message and does not allow verifying whether the sender of the NDP message is actually authorized for the information for the provisioning domain. If the PVD_CO contains a signature and the verification fails, then the whole PVD_CO MUST be silently discarded and the event SHOULD be logged. 4. PVD Identity option The PVD identity option (PVD_ID) is used to explicitly indicate the identity of the provisioning domain that is associated with the configuration information encapsulated by the PVD container option. A PVD container MUST have exactly one PVD identity option. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=PVD_ID | Length | ID-Type | ID-Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Provisioning Domain Identifier ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: PVD_ID Option Type PVD identifier; Set to TBA2. Length Length of the PVD_ID. ID-Type Describes the type of identification information. This document defines four types of PVD identity information: Korhonen & Krishnan Expires April 24, 2014 [Page 6] Internet-Draft NDP PVD support October 2013 0x01: UUID [RFC4122] 0x02: UTF-8 string 0x03: OID [OID] 0x03: NAI Realm [RFC4282] ID-Length Length of the Provisioning Domain Identifier in octets. Provisioning Domain Identifier The PVD identification that is based on the id-type. The identifier MUST be '\0' octet padded until the PVD_ID option length is multiple of 8 octet. If the receiver of the PVD_ID option does not understand any of the ID-Types, then the whole encapsulating PVD_CO MUST be silently discarded. 5. Set of allowable options The PVD container option MAY be used to encapsulate any allocated IPv6 NDP options but MUST NOT be used to encapsulate another PVD_CO option. [TODO: Should we add any other exclusions?]. 6. Security Considerations An attacker may attempt to modify the information provided inside the PVD container option. These attacks can easily be prevented by using SeND [RFC3971] or per PVD container signature that would detect any form of tampering with the IPv6 NDP message contents. A compromised router may advertise configuration information related to PvDs it is not authorized to advertise. e.g. A coffee shop router may provide configuration information purporting to be from an enterprise and may try to attract enterprise related traffic. The only real way to avoid this is that the PvD container contains embedded authentication and authorization information from the owner of the PvD. Then, this attack can be detected by the client by verifying the authentication and authorization information provided inside the PVD container option after verifying its trust towards the PvD owner (e.g. a certificate with a well-known/common trust anchor). A compromised configuration source or an on-link attacker may try to capture advertised configuration information and replay it on a different link or at a future point in time. This can be avoided by Korhonen & Krishnan Expires April 24, 2014 [Page 7] Internet-Draft NDP PVD support October 2013 including some replay protection mechanism such as a timestamp or a nonce inside the PvD container to ensure freshness of the provided information. 7. IANA Considerations This document defines new IPv6 Neighbor discovery options from the registry at http://www.iana.org/assignments/icmpv6-parameters/ icmpv6-parameters.xhtml#icmpv6-parameters-5 PVD_CO: TBA1 PVD_ID: TBA2 This document reuses information from a new registry for PVD Identity types http://www.iana.org/assignments/dhcpv6-parameters/ 8. Acknowledgements The authors would like to thank the members of the MIF architecture design team for their comments that led to the creation of this draft. 9. References 9.1. Normative References [OID] IANA, "PRIVATE ENTERPRISE NUMBERS", SMI Network Management Private Enterprise Codes, http://www.iana.org/ assignments/enterprise-numbers/enterprise-numbers. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally Unique IDentifier (UUID) URN Namespace", RFC 4122, July 2005. [RFC4282] Aboba, B., Beadles, M., Arkko, J., and P. Eronen, "The Network Access Identifier", RFC 4282, December 2005. [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007. Korhonen & Krishnan Expires April 24, 2014 [Page 8] Internet-Draft NDP PVD support October 2013 [RFC6494] Gagliano, R., Krishnan, S., and A. Kukec, "Certificate Profile and Certificate Management for SEcure Neighbor Discovery (SEND)", RFC 6494, February 2012. [RFC6495] Gagliano, R., Krishnan, S., and A. Kukec, "Subject Key Identifier (SKI) SEcure Neighbor Discovery (SEND) Name Type Fields", RFC 6495, February 2012. 9.2. Informative References [I-D.anipko-mif-mpvd-arch] Anipko, D., "Multiple Provisioning Domain Architecture", draft-anipko-mif-mpvd-arch-04 (work in progress), October 2013. [RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure Neighbor Discovery (SEND)", RFC 3971, March 2005. [RFC6487] Huston, G., Michaelson, G., and R. Loomans, "A Profile for X.509 PKIX Resource Certificates", RFC 6487, February 2012. Authors' Addresses Jouni Korhonen Broadcom Porkkalankatu 24 FIN-00180 Helsinki Finland Email: jouni.nospam@gmail.com Suresh Krishnan Ericsson 8400 Decarie Blvd. Town of Mount Royal, QC Canada Phone: +1 514 345 7900 x42871 Email: suresh.krishnan@ericsson.com Korhonen & Krishnan Expires April 24, 2014 [Page 9]