RFC 7318

RFC 7318: Policy Qualifiers in Resource Public Key Infrastructure (RPKI) Certificates ✨

Okay bestie, this one is from the IETF, published July 2014. The authors are A. Newton (ARIN) and G. Huston (APNIC) 🦋. It's a Standards Track document, ISSN 2070-1721, and it updates RFC 6487. The header doesn't list anything it obsoletes. It's all about letting RPKI resource certificates carry policy qualifiers 💅

Abstract

This document updates RFC 6487 by clarifying that policy qualifiers can be included in the certificate policies extension of Resource Public Key Infrastructure (RPKI) resource certificates 🌸

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). For more on Internet Standards, check Section 2 of RFC 5741 🧚

Info about the current status of this document, any errata, and how to give feedback is at http://www.rfc-editor.org/info/rfc7318 💜

Copyright Notice

Copyright (c) 2014 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, since they spell out your rights and restrictions for 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 they're provided without warranty as described in the Simplified BSD License 🫶

Table of Contents

1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
2.  Update to RFC 6487  . . . . . . . . . . . . . . . . . . . . .   2
3.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
4.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   4
5.  Normative References  . . . . . . . . . . . . . . . . . . . .   4

1. Introduction 🌈

Okay so this document brings policy qualifiers into the certificate policies extension of RPKI resource certificates. It also updates [RFC6487] 🦋

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]. Those capitalized words are the requirement-level vocabulary, so read them carefully 💅

2. Update to RFC 6487 💖

[RFC6487] profiles certificates, certificate revocation lists, and certificate signing requests specified in [RFC5280] for use in routing public key infrastructure. So it's the rulebook for the routing PKI 📜

[RFC5280] defines an extension to certificates for listing policy information (see Section 4.2.1.4). [RFC6487] states in Section 4.8.9: "This extension MUST be present and MUST be marked critical. It MUST include exactly one policy, as specified in the RPKI CP [RFC6484]." That points at the CertPolicyId of the sequence allowed in PolicyInformation, as defined by [RFC5280] 🔥

[RFC5280] also says PolicyInformation may optionally have a sequence of PolicyQualifierInfo objects. [RFC6487] doesn't specifically allow or disallow these PolicyQualifierInfo objects. Section 4 does say, though: "Unless specifically noted as being OPTIONAL, all the fields listed here MUST be present, and any other fields MUST NOT appear in a conforming resource certificate." 🙈 Since some RPKI Certificate Authorities need to include policy qualifiers in their certificates, this document updates Section 4.8.9 of [RFC6487] like so:

   OLD:

      This extension MUST be present and MUST be marked critical.  It
      MUST include exactly one policy, as specified in the RPKI
      Certificate Policy (CP) [RFC6484].

   NEW:

      This extension MUST be present and MUST be marked critical.  It
      MUST include exactly one policy, as specified in the RPKI CP
      [RFC6484].  Exactly one policy qualifier MAY be included.  If a
      policy qualifier is included, the policyQualifierId MUST be the
      Certification Practice Statement (CPS) pointer qualifier type
      (id-qt-cps).

As [RFC5280], Section 4.2.1.4 notes: "Optional qualifiers, which MAY be present, are not expected to change the definition of the policy." 🧚 So in this case, any optional policy qualifier that MAY be present in a resource certificate MUST NOT change the definition of the RPKI CP [RFC6484] ✨ That's the whole vibe: optional qualifier, same policy 💜

3. Security Considerations 🔐

This one's serious, so listen up 👑 The Security Considerations of [RFC6487] apply to this document.

This document updates the RPKI certificate profile so that the certificate policies extension can include a policy qualifier, and that qualifier is a URI. Dereferencing the URI is not required for certificate validation. Doing so could still open a denial-of-service (DoS) vector, where the target host gets hit with bogus work from dereferencing the URI 😭 Also, this specification, like [RFC5280], places no processing requirements on the URI included in the qualifier.

As an update to [RFC6487], this document widens the class of certificates that conform to the RPKI profile. It does that by explicitly including certificates that contain a policy qualifier as described here. A relying party that does strict validation based on [RFC6487] and doesn't support the updates in this document would incorrectly invalidate RPKI objects that include the changes in Section 2. Yikes, that's a whole validation disaster 💀 so please support the update!

4. Acknowledgments 🌸

Frank Hill and Adam Guyot helped define the scope of the issue covered by this document. They also identified and worked with RPKI validator implementers to clarify how policy qualifiers get used in resource certificates 🫶

Sean Turner provided significant text to this document about processing the CPS URI and about limiting the allowable content of the policy qualifier 🦋

5. Normative References 📚

• [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
• [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.
• [RFC6484] Kent, S., Kong, D., Seo, K., and R. Watro, "Certificate Policy (CP) for the Resource Public Key Infrastructure (RPKI)", BCP 173, RFC 6484, February 2012.
• [RFC6487] Huston, G., Michaelson, G., and R. Loomans, "A Profile for X.509 PKIX Resource Certificates", RFC 6487, February 2012.

Authors' Addresses 🎀

Andrew Lee Newton
American Registry for Internet Numbers
3635 Concorde Parkway
Chantilly, VA  20151
USA

EMail: andy@arin.net
URI:   http://www.arin.net


Geoff Huston
Asia Pacific Network Information Center
6 Cordelia Street
South Brisbane  QLD 4101
Australia

EMail: gih@apnic.net
URI:   http://www.apnic.net

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That's the whole RFC, bestie! 🌈✨ Policy qualifiers are allowed now, the policy definition stays put, and validators have to actually support the update 🔥👑