Network Working Group R. Bush Internet-Draft Internet Initiative Japan & Arrcus, Inc. Intended status: Informational J. Snijders Expires: October 23, 2020 NTT April 21, 2020 Timing Parameters in the RPKI based Route Origin Validation Supply Chain draft-ymbk-rpki-rov-timing-00 Abstract This document explores, and makes recommendations for, timing of Resource Public Key Infrastructure publication, propagation, and use of RPKI ROV data in relying parties and routers. 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. 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 https://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 October 23, 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 Provisions Relating to IETF Documents Bush & Snijders Expires October 23, 2020 [Page 1] Internet-Draft RPKI ROV Timing April 2020 (https://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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Related Work . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Deployment Structure . . . . . . . . . . . . . . . . . . . . 3 4. Certification Authority Publishing . . . . . . . . . . . . . 4 5. Replying Party Fetching . . . . . . . . . . . . . . . . . . . 4 6. Router Updating . . . . . . . . . . . . . . . . . . . . . . . 4 7. Alternative Technologies . . . . . . . . . . . . . . . . . . 4 8. Security Considerations . . . . . . . . . . . . . . . . . . . 5 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 10.1. Normative References . . . . . . . . . . . . . . . . . . 5 10.2. Informative References . . . . . . . . . . . . . . . . . 6 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction As Resource Public Key Infrastructure (RPKI) based Route Origin Validation (ROV) becomes deployed in the Internet, the quality of the routing control plane, and hence timely and accurate delivery of packets in the data plane, depend more and more on prompt and accurate propagation of the RPKI data from the originating Certification Authorities (CAs), to Relying Parties (RPs), to External Border Gateway Protocol (eBGP) speaking routers. Origination Validation based on stale ROAs allows accidental mis- origination. While delayed ROA propagation to ROV in routers can cause loss of good traffic. Though it may not be reasonable today, services such as DDoS cleaners would prefer that ROA publication had almost immediate effect on routing. This draft is an exploration of, and recommendations for, timing of Resource Public Key Infrastructure publication, propagation, and use in relying party caches and routers. There are the questions of how frequently a CA publishes, how often an RP pulls, and how often routers pull from their RP(s). Overall, the router(s) SHOULD react within an hour of to ROA publication. Bush & Snijders Expires October 23, 2020 [Page 2] Internet-Draft RPKI ROV Timing April 2020 For CAs publishing, a few seconds to a minute seems easily achieved with reasonable software. See Section 4. Relying Party validating caches periodically retrieve data from CA publication points.. RPs using rcynic to poll publication points every ten minutes would be a burden today, given the load it will put on publication services, and one notorious repository which is against specification. But RPs using RRDP impose no such load. So as the infrastructure moves from rcynic to RRDP, fetching every ten minutes would be reasonable. For rcynic, an hour would be the longest acceptable window. See Section 5. For the BGP speaking router(s) pulling from the RP(s), five minutes to an hour is a wide window. But, the RPKI-Rtr protocol does have the Serial Notify PDU, the equivalent of DNS Notify, where the cache tells the router that it has new data. See Section 6. We discuss each of these in detail below. 2. Related Work It is assumed that the reader understands BGP, [RFC4271], the RPKI [RFC6480], RPKI Manifests [RFC6486], Route Origin Authorizations (ROAs), [RFC6482], the RPKI Repository Delta Protocol (RRDP) [RFC8182], The Resource Public Key Infrastructure (RPKI) to Router Protocol [I-D.ietf-sidrops-8210bis], RPKI-based Prefix Validation, [RFC6811], and Origin Validation Clarifications, [RFC8481]. 3. Deployment Structure Deployment of the RPKI to reach routers has a three-level structure as follows: Cerification Authorities: The authoritative data of the RPKI are published in a distributed set of servers, Certification Authorities, at the IANA, RIRs, NIRs, and ISPs (see [RFC6481]). Relying Parties: Relying Parties are a local set of one or more collected and verified caches of RPKI data. A Relying Party, e.g., router or other client, MUST have a trust relationship with, and a trusted transport channel to, any RP(s) it uses. Note that RPs can pull from other RPs, thereby creating a somewhat complex topology. Routers: A router fetches data from a local cache using the RPKI to Router Protocol described in [I-D.ietf-sidrops-8210bis]. It is said to be a client of the cache. There are mechanisms for the Bush & Snijders Expires October 23, 2020 [Page 3] Internet-Draft RPKI ROV Timing April 2020 router to assure itself of the authenticity of the cache and to authenticate itself to the cache. 4. Certification Authority Publishing A principal constraint on publication timing is ensuring the CRL and Manifest ([RFC6486]) are atomically correct with respect to the other repository data. With rcynic, the directory must be atomically correct before it becomes current. RRDP ([RFC8182]) is similar, the directory must be atomically correct before it is published. 5. Replying Party Fetching rcynic puts a load on RPKI publication point servers. Therefore relying party caches have been discouraged from fetching more frequently than on the order of an hour. Times as long as a day were even suggested. With RRDP ([RFC8182]), these constraints are no longer relevant. A number of timers are embedded in the X.509 RPKI data which should also be considered. E.g., CRL publication commitments, expiration of EE certificates pointing to Manifests and the Manifests themselves. Some CA operators commonly indicate new CRL information should be available in the next 24 hours. These 24-hour sliding timers, combined with fetching RPKI data once a day, cause needless brittleness in the face of transient network issues between the CA and RP. 6. Router Updating The rate of change of ROA data can be estimated to remain small, maybe on the order of a few ROAs a minute, but with bursts. Therefore, the routers may update from the (presumed local) relying party cache(s) quite frequently. Note that [I-D.ietf-sidrops-8210bis] recommends a polling interval of one hour. This conservative timing is because caches can send a Serial Notify PDU to tell routers when there are new data to be fetched. A router SHOULD respond with a Serial Query when it receives a Serial Notify from a cache. If a router can not respond to a Serial Notify, then it MUST send a periodic Serial Query no less frequently than once an hour. 7. Alternative Technologies Should the supply chain include components or technologies other than those in IETF documents, the end effect SHOULD be the same; the router(s) SHOULD react to invalid AS origins within the same overall Bush & Snijders Expires October 23, 2020 [Page 4] Internet-Draft RPKI ROV Timing April 2020 time constraint, an hour at most from ROA creation at the CA publication point to effect in the router. 8. Security Considerations Route Origin Validation is not a security protocol. It is intended to catch operational errors, and is easily gamed and attacked. 9. IANA Considerations None 10. References 10.1. Normative References [I-D.ietf-sidrops-8210bis] Bush, R. and R. Austein, "The Resource Public Key Infrastructure (RPKI) to Router Protocol, Version 2", draft-ietf-sidrops-8210bis-00 (work in progress), March 2020. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, January 2006, . [RFC6481] Huston, G., Loomans, R., and G. Michaelson, "A Profile for Resource Certificate Repository Structure", RFC 6481, DOI 10.17487/RFC6481, February 2012, . [RFC6482] Lepinski, M., Kent, S., and D. Kong, "A Profile for Route Origin Authorizations (ROAs)", RFC 6482, DOI 10.17487/RFC6482, February 2012, . [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, . Bush & Snijders Expires October 23, 2020 [Page 5] Internet-Draft RPKI ROV Timing April 2020 [RFC6811] Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R. Austein, "BGP Prefix Origin Validation", RFC 6811, DOI 10.17487/RFC6811, January 2013, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8182] Bruijnzeels, T., Muravskiy, O., Weber, B., and R. Austein, "The RPKI Repository Delta Protocol (RRDP)", RFC 8182, DOI 10.17487/RFC8182, July 2017, . [RFC8481] Bush, R., "Clarifications to BGP Origin Validation Based on Resource Public Key Infrastructure (RPKI)", RFC 8481, DOI 10.17487/RFC8481, September 2018, . 10.2. Informative References [RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480, February 2012, . Appendix A. Acknowledgements The authors wish to thank Massimiliano Stucchi. Authors' Addresses Randy Bush Internet Initiative Japan & Arrcus, Inc. 5147 Crystal Springs Bainbridge Island, Washington 98110 United States of America Email: randy@psg.com Job Snijders NTT Ltd. Theodorus Majofskistraat 100 Amsterdam 1065 SZ The Netherlands Email: job@ntt.net Bush & Snijders Expires October 23, 2020 [Page 6]