Internet Engineering Task Force (IETF) G. Huston Request for Comments: 7730 APNIC Obsoletes: 6490 S. Weiler Category: Standards Track Parsons ISSN: 2070-1721 G. Michaelson APNIC S. Kent BBN January 2016 Resource Public Key Infrastructure (RPKI) Trust Anchor Locator
AbstractThis document defines a Trust Anchor Locator (TAL) for the Resource Public Key Infrastructure (RPKI). This document obsoletes RFC 6490 by adding support for multiple URIs in a TAL. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7730. Copyright Notice Copyright (c) 2016 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 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.
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 2 2. Trust Anchor Locator . . . . . . . . . . . . . . . . . . . . 2 2.1. Trust Anchor Locator Format . . . . . . . . . . . . . . . 2 2.2. TAL and Trust Anchor Certificate Considerations . . . . . 3 2.3. Example . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Relying Party Use . . . . . . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.1. Normative References . . . . . . . . . . . . . . . . . . 6 5.2. Informative References . . . . . . . . . . . . . . . . . 7 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 RFC6480]. This format may be used to distribute trust anchor material using a mix of out-of-band and online means. Procedures used by Relying Parties (RPs) to verify RPKI signed objects SHOULD support this format to facilitate interoperability between creators of trust anchor material and RPs. This document obsoletes RFC 6490 by adding support for multiple URIs in a TAL. RFC2119].
extensions that represent Internet Number Resources (INRs) [RFC3779]. The set of INRs associated with an entity acting as a trust anchor is likely to change over time. Thus, if one were to use the common PKI convention of distributing a trust anchor to RPs in a secure fashion, then this procedure would need to be repeated whenever the INR set for the entity acting as a trust anchor changed. By distributing the TAL (in a secure fashion), instead of distributing the trust anchor, this problem is avoided, i.e., the TAL is constant so long as the trust anchor's public key and its location do not change. The TAL is analogous to the TrustAnchorInfo data structure specified in [RFC5914], which is on the Standards Track. That specification could be used to represent the TAL, if one defined an rsync URI extension for that data structure. However, the TAL format was adopted by RPKI implementors prior to the PKIX trust anchor work, and the RPKI implementer community has elected to utilize the TAL format, rather than define the requisite extension. The community also prefers the simplicity of the ASCII encoding of the TAL, versus the binary (ASN.1) encoding for TrustAnchorInfo. The TAL is an ordered sequence of: 1) a URI section, 2) a <CRLF> or <LF> line break, 3) a subjectPublicKeyInfo [RFC5280] in DER format [X.509], encoded in Base64 (see Section 4 of [RFC4648]). To avoid long lines, <CRLF> or <LF> line breaks MAY be inserted into the Base64-encoded string. where the URI section is comprised of one of more of the ordered sequence of: 1.1) an rsync URI [RFC5781], 1.2) a <CRLF> or <LF> line break. RFC6487]. This certificate is the trust anchor in certification path discovery [RFC4158] and validation [RFC5280] [RFC3779].
The validity interval of this trust anchor SHOULD reflect the anticipated period of stability of the particular set of INRs that are associated with the putative trust anchor. The INR extension(s) of this trust anchor MUST contain a non-empty set of number resources. It MUST NOT use the "inherit" form of the INR extension(s). The INR set described in this certificate is the set of number resources for which the issuing entity is offering itself as a putative trust anchor in the RPKI [RFC6480]. The public key used to verify the trust anchor MUST be the same as the subjectPublicKeyInfo in the CA certificate and in the TAL. The trust anchor MUST contain a stable key. This key MUST NOT change when the certificate is reissued due to changes in the INR extension(s), when the certificate is renewed prior to expiration, or for any reason other than a key change. Because the public key in the TAL and the trust anchor MUST be stable, this motivates operation of that CA in an offline mode. Thus, the entity that issues the trust anchor SHOULD issue a subordinate CA certificate that contains the same INRs (via the use of the "inherit" option in the INR extensions of the subordinate certificate). This allows the entity that issues the trust anchor to keep the corresponding private key of this certificate offline, while issuing all relevant child certificates under the immediate subordinate CA. This measure also allows the Certificate Revocation List (CRL) issued by that entity to be used to revoke the subordinate CA certificate in the event of suspected key compromise of this online operational key pair that is potentially more vulnerable. The trust anchor MUST be published at a stable URI. When the trust anchor is reissued for any reason, the replacement CA certificate MUST be accessible using the same URI. Because the trust anchor is a self-signed certificate, there is no corresponding CRL that can be used to revoke it, nor is there a manifest [RFC6486] that lists this certificate. If an entity wishes to withdraw a self-signed CA certificate as a putative trust anchor, for any reason, including key rollover, the entity MUST remove the object from the location referenced in the TAL. Where the TAL contains two or more rsync URIs, then the same self- signed CA certificate MUST be found at each referenced location. In order to increase operational resilience, it is RECOMMENDED that the domain name parts of each of these URIs resolve to distinct IP
addresses that are used by a diverse set of repository publication points, and these IP addresses be included in distinct Route Origin Authorizations (ROAs) objects signed by different CAs. RFC6487]. 3. Confirm that the public key in the TAL matches the public key in the retrieved object. 4. Perform other checks, as deemed appropriate (locally), to ensure that the RP is willing to accept the entity publishing this self- signed CA certificate to be a trust anchor. These tests apply to the validity of attestations made in the context of the RPKI relating to all resources described in the INR extension of this certificate. An RP SHOULD perform these functions for each instance of TAL that it is holding for this purpose every time the RP performs a resynchronization across the local repository cache. In any case, an RP also SHOULD perform these functions prior to the expiration of the locally cached copy of the retrieved trust anchor referenced by the TAL.
In the case where a TAL contains multiple URIs, an RP MAY use a locally defined preference rule to select the URI to retrieve the self-signed RPKI CA certificate that is to be used as a trust anchor. Some examples are: o Using the order provided in the TAL o Selecting the URI randomly from the available list o Creating a prioritized list of URIs based on RP-specific parameters, such as connection establishment delay If the connection to the preferred URI fails, or the retrieved CA certificate public key does not match the TAL public key, the RP SHOULD retrieve the CA certificate from the next URI, according to the local preference ranking of URIs. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <http://www.rfc-editor.org/info/rfc2119>. [RFC3779] Lynn, C., Kent, S., and K. Seo, "X.509 Extensions for IP Addresses and AS Identifiers", RFC 3779, DOI 10.17487/RFC3779, June 2004, <http://www.rfc-editor.org/info/rfc3779>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, <http://www.rfc-editor.org/info/rfc4648>. [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, DOI 10.17487/RFC5280, May 2008, <http://www.rfc-editor.org/info/rfc5280>. [RFC5781] Weiler, S., Ward, D., and R. Housley, "The rsync URI Scheme", RFC 5781, DOI 10.17487/RFC5781, February 2010, <http://www.rfc-editor.org/info/rfc5781>. [RFC6487] Huston, G., Michaelson, G., and R. Loomans, "A Profile for X.509 PKIX Resource Certificates", RFC 6487, DOI 10.17487/RFC6487, February 2012, <http://www.rfc-editor.org/info/rfc6487>. [X.509] ITU-T, "The Directory: Public-key and attribute certificate frameworks", ITU-T Recommendation X.509, ISO/IEC 9594-8, October 2012. [RFC4158] Cooper, M., Dzambasow, Y., Hesse, P., Joseph, S., and R. Nicholas, "Internet X.509 Public Key Infrastructure: Certification Path Building", RFC 4158, DOI 10.17487/RFC4158, September 2005, <http://www.rfc-editor.org/info/rfc4158>. [RFC5914] Housley, R., Ashmore, S., and C. Wallace, "Trust Anchor Format", RFC 5914, DOI 10.17487/RFC5914, June 2010, <http://www.rfc-editor.org/info/rfc5914>. [RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480, February 2012, <http://www.rfc-editor.org/info/rfc6480>. [RFC6486] Austein, R., Huston, G., Kent, S., and M. Lepinski, "Manifests for the Resource Public Key Infrastructure (RPKI)", RFC 6486, DOI 10.17487/RFC6486, February 2012, <http://www.rfc-editor.org/info/rfc6486>.
http://www.apnic.net Samuel Weiler Parsons 7110 Samuel Morse Drive Columbia, MD 21046 United States Email: firstname.lastname@example.org George Michaelson APNIC Email: email@example.com URI: http://www.apnic.net Stephen Kent BBN Technologies 10 Moulton St. Cambridge, MA 02138 United States Email: firstname.lastname@example.org