Network Working Group S. Krishnan Internet-Draft Ericsson Intended status: Standards Track A. Kukec Expires: April 29, 2010 University of Zagreb R. Gagliano LACNIC October 26, 2009 Certificate profile and certificate management for SEND draft-ietf-csi-send-cert-01 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. 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The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 29, 2010. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the Krishnan, et al. Expires April 29, 2010 [Page 1] Internet-Draft SEND certificate profile and management October 2009 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. Krishnan, et al. Expires April 29, 2010 [Page 2] Internet-Draft SEND certificate profile and management October 2009 Abstract SEcure Neighbor Discovery (SEND) Utilizes X.509v3 certificates for performing router authorization. This document specifies a certificate profile for SEND based on Resource Certificates along with extended key usage values required for SEND. Table of Contents 1. Requirements notation . . . . . . . . . . . . . . . . . . . . 4 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Deployment Models . . . . . . . . . . . . . . . . . . . . . . 7 5. Certificate profile and issuance . . . . . . . . . . . . . . . 8 5.1. Trust Anchor Material . . . . . . . . . . . . . . . . . . 8 5.2. Extended Key Usage Values . . . . . . . . . . . . . . . . 8 6. CRL profile and revocation . . . . . . . . . . . . . . . . . . 11 6.1. Certificate Revocation Solicitation message . . . . . . . 11 6.2. Certificate Revocation Advertisement message . . . . . . . 11 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 8. Normative References . . . . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 Krishnan, et al. Expires April 29, 2010 [Page 3] Internet-Draft SEND certificate profile and management October 2009 1. Requirements notation 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]. Krishnan, et al. Expires April 29, 2010 [Page 4] Internet-Draft SEND certificate profile and management October 2009 2. Introduction SEcure Neighbor Discovery [RFC3971] (SEND) utilizes X.509v3 certificates that include the [RFC3779] extension for IPv6 addresses to certify a router's authority over an IPv6 prefix for the Neighbor Discovery (ND) Protocol. SEND specification defines neither the certificate profile nor any certificate management routines. It specifies only the certificate path validation and the IP address extension verification procedures. This document defines the certificate profile, as well as certificate issuance and revocation routines for SEND. The SIDR WG in the IETF is working on a Certificate Profile for the Resource Public Key Infrastructure (RPKI). The RPKI represents the centralized model referred in Section 6.2 of [RFC3971]. Consequently, the SIDR certificate profile and certificate validation detailed in [draft-ietf-sidr-res-certs-17] MUST be used for SEND. The RFC 3779 extension for IPv6 addresses can be expressed as either an addressPrefix or an addressRange. For SEND it does not matter how the IPv6 address space is expressed (either an addressPrefix or an addressRange) in the certificate as long as the IPv6 address space that the entity is allowed to route is included. We will use the term "certified IPv6 space" to refer to the IPv6 address space included in an X.509v3 certificate using RFC 3779 extension for IPv6 addresses. Since the IPv6 addresses extension does not mention what functions the node can perform for the certified IPv6 space, it becomes impossible to know the reason for which the certificate was issued. In order to facilitate issuance of certificates for specific functions, it is necessary to utilize the ExtKeyUsageSyntax field (optional in RPKI Certificates) of the X.509 certificate to mention the purpose why the certificate was issued. This document specifies three extended key usage values, one for routers, one for proxies, and one for address owners, for use with SEND. In RFC 3971 two deployment models were described: centralized and decentralized. With the advance of RPKI standardization we introduce two different deployment models: local and public deployment models. Krishnan, et al. Expires April 29, 2010 [Page 5] Internet-Draft SEND certificate profile and management October 2009 3. Terminology Certified IPv6 Addresses IPv6 address space included in an X.509v3 certificate using RFC 3779 extension for IPv6 addresses. ISP Internet Service Provider. NIR National Internet Registry. RIR Regional Internet Registry. RPKI Resource PKI established in accordance with [draft-ietf-sidr-arch-06]. RPKI certificates Certificates defined in [draft-ietf-sidr-res-certs-17]. SEND certificates Certificates described in [RFC3971] and extended in this document. They belong either to SEND routers or Secure Proxy ND nodes: * Router Authorization Certificate and parent certificates in the Authorization Delegation chain. There is no difference in the profile of the Router Authorization Certificate and other (parent) certificates in the Authorization Delegation process. * Secure Proxy ND certificates for ND Proxy, Mobile IPv6 Home Agent or Proxy Mobile Access Gateway [draft-ietf-csi-proxy-send-00]. CA and end entity certificates issued in support of SEND MUST comply with the RPKI resource profile [draft-ietf-sidr-res-certs-17]. Krishnan, et al. Expires April 29, 2010 [Page 6] Internet-Draft SEND certificate profile and management October 2009 4. Deployment Models RFC 3971 describes two deployment models:centralized and decentralized. These models were differentiated by having one or many trust anchor. In this document we introduced two new deployment models, not based on the number of trust anchors but on the localization of the SEND deployment The local SEND deployment model represent those cases where SEND deployment is confined to an administrative domain. In this scenario, the deployment of SEND MAY be done independently of the existance of deployment in the upper RPKI hierarchy (i.e. and end user could deploy SEND without the need of RPKI deployment in its ISP) by the use of local trust anchors and configuring islands of trust. This model MAY include ULA addresses. The public SEND deployment models represent those cases where SEND deployment is linked to RPKI deployment as described in [draft-ietf-sidr-arch-06]. Trust anchor material MAY be part of a different administrative domain (i.e. RIR, NIR or ISPs). It is a global model suitable for mobile users. Krishnan, et al. Expires April 29, 2010 [Page 7] Internet-Draft SEND certificate profile and management October 2009 5. Certificate profile and issuance End entity certificates issued in support of SEND MUST comply with the RPKI resource profile [draft-ietf-sidr-res-certs-17]. CA certificates used to verify these router (EE) certificates also MUST comply with this profile. This implies that these CA certificates MUST contain an RFC 3779 address extension representing the address space allocations held by the service provider represented by the CA. 5.1. Trust Anchor Material Relying parties (e.g., user devices that implement SEND and process these router certificates) MUST be configured with one or more trust anchors, to enable validation of the routers' certificates. The trust anchor material MAY be either a CA certificate (which MAY be self-signed) containing an RFC 3779 address extension or MAY be trust anchor material as defined in [draft-ietf-sidr-ta-02]. In a local SEND deployment model, it is possible to use as a trust anchor material a certificate that includes in its RFC 3779 address extension the prefix ::/0. In this case no new trust anchor material would be needed when renumbering. However, if trying to move from the local deployment model to the public deployment model, new trust anchor material will have to be distributed to relying parties. By using the trust anchor model described in [draft-ietf-sidr-ta-02], no address space is part of the trust anchor material. This allows network renumbering without the need for issuing trust anchor material in bith the local and the public model. In this case the Relying party MUST obtain a certificate that includes an RFC 3779 address extension. This certificate will be obtained from the publication point of certificate defined as trust anchor. The identification for the Trust Anchor Material will be included in the Name Type Field of the ICMP Trust Anchor Option as decribed in RFC 3971 and MUST always to refer to a certificate that includes as RFC 3779 address extension. 5.2. Extended Key Usage Values The Internet PKI document [RFC5280] specifies the extended key usage X.509 certificate extension. The extension indicates one or more purposes for which the certified public key may be used. The extended key usage extension can be used in conjunction with key usage extension, which indicates the intended purpose of the certified public key. The Extended Key Usage extension is defined as optional in [draft-ietf-sidr-res-certs-17] for end entity certificates but MUST be present when issuing end entity certificates Krishnan, et al. Expires April 29, 2010 [Page 8] Internet-Draft SEND certificate profile and management October 2009 for SEND. The extended key usage extension syntax is repeated here for convenience: ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId KeyPurposeId ::= OBJECT IDENTIFIER This specification defines three KeyPurposeId values: one for authorizing routers, one for authorizing proxies, and one for address owners. The inclusion of the router authorization value indicates that the certificate has been issued for allowing the router to advertise prefix(es) that are mentioned using the X.509 extensions for IP addresses and AS identifiers [RFC3779] The inclusion of the proxy authorization value indicates that the certificate has been issued for allowing the proxy to perform proxying of neighbor discovery messages for the prefix(es) that are mentioned using the X.509 extensions for IP addresses and AS identifiers [RFC3779] The inclusion of the owner authorization value indicates that the certificate has been issued for allowing the node to use the address(es) or prefix(es) that are mentioned using the X.509 extensions for IP addresses and AS identifiers [RFC3779] Inclusion of multiple values indicates that the certified public key is appropriate for use by a node performing more than one of these functions. send-kp OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) TBA1 } id-kp-sendRouter OBJECT IDENTIFIER ::= { send-kp 1 } id-kp-sendProxy OBJECT IDENTIFIER ::= { send-kp 2 } id-kp-sendOwner OBJECT IDENTIFIER ::= { send-kp 3 } The extended key usage extension MAY, at the option of the certificate issuer, be either critical or non-critical. Certificate-using applications MAY require the extended key usage extension to be present in a certificate, and they MAY require a Krishnan, et al. Expires April 29, 2010 [Page 9] Internet-Draft SEND certificate profile and management October 2009 particular KeyPurposeId value to be present (such as id-kp-sendRouter or id-kp-sendProxy) within the extended key usage extension. If multiple KeyPurposeId values are included, the certificate-using application need not recognize all of them, as long as the required KeyPurposeId value is present. Krishnan, et al. Expires April 29, 2010 [Page 10] Internet-Draft SEND certificate profile and management October 2009 6. CRL profile and revocation RPKI requires the use of CRLs [draft-ietf-sidr-res-certs-17]. CRLs require an in-band exchange of the revocation material, and the specification of new SEND messages - Certificate Revocation Solicitation (CRS) message and the Certificate Revocation Advertisement (CRA) message. While receiving a CPA message, SEND host does not have an access to Internet, and therefore MUST accept certificates within the CPA message, and consider them as provisional. Once when the SEND host gains Internet access, it MUST send the Certificate Revocation Solicitation (CRS) message to request the CRL, and then perform the revocation after the receipt of the CRL within the Certificate Revocation Advertisement (CRA) message. 6.1. Certificate Revocation Solicitation message TBD. 6.2. Certificate Revocation Advertisement message TBD. Krishnan, et al. Expires April 29, 2010 [Page 11] Internet-Draft SEND certificate profile and management October 2009 7. Security Considerations The certification authority needs to ensure that the correct values for the extended key usage are inserted in each certificate that is issued. Relying parties may accept or reject a particular certificate for an intended use based on the information provided in these extensions. Incorrect representation of the information in the extended key usage field can cause the relying party to reject an otherwise appropriate certificate or accept a certificate that ought to be rejected. Krishnan, et al. Expires April 29, 2010 [Page 12] Internet-Draft SEND certificate profile and management October 2009 8. Normative References [I-D.ietf-sidr-res-certs] Huston, G., Michaelson, G., and R. Loomans, "A Profile for X.509 PKIX Resource Certificates", draft-ietf-sidr-res-certs-17 (work in progress), September 2009. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3779] Lynn, C., Kent, S., and K. Seo, "X.509 Extensions for IP Addresses and AS Identifiers", RFC 3779, June 2004. [RFC3971] Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure Neighbor Discovery (SEND)", RFC 3971, March 2005. [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, May 2008. Krishnan, et al. Expires April 29, 2010 [Page 13] Internet-Draft SEND certificate profile and management October 2009 Authors' Addresses Suresh Krishnan Ericsson 8400 Decarie Blvd. Town of Mount Royal, QC Canada Phone: +1 514 345 7900 x42871 Email: suresh.krishnan@ericsson.com Ana Kukec University of Zagreb Unska 3 Zagreb Croatia Email: ana.kukec@fer.hr Roque Gagliano LACNIC Rambla Rep Mexico 6125 Montevideo, 11400 UY Email: roque@lacnic.net Krishnan, et al. Expires April 29, 2010 [Page 14]