TBD T. Ito Internet-Draft SECOM CO., LTD. Updates: 5480 (if approved) S. Turner Intended status: Standards Track sn3rd Expires: February 14, 2020 August 13, 2019 Clarifications for Elliptic Curve Cryptogtaphy Subject Public Key Information draft-turner-5480-ku-clarifications-01 Abstract This document updates RFC 5480 to specify semantics for the keyEncipherment and dataEncipherment key usage bits when used in certificates that support Elliptic Curve Cryptography. 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 February 14, 2020. Copyright Notice Copyright (c) 2019 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. Ito & Turner Expires February 14, 2020 [Page 1] Internet-Draft Clarifications for ECC SPKI August 2019 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Updates to Section 3 . . . . . . . . . . . . . . . . . . . . 2 4. Security Considerations . . . . . . . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . 3 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction [RFC5480] specifies the syntax and semantics for the Subject Public Key Information field in certificates that support Elliptic Curve Cryptography. As part of these semantics, it defines what combinations are permissible for the values of the key usage extensions [RFC5280]. [RFC5480] specifies 7 of the 9 values; it makes no mention of keyEncipherment and dataEncipherment key usage bits. This document corrects this omission, by updating Section 3 of [RFC5480] to make it clear that neither keyEncipherment nor the dataEncipherment key usage bits are set for key agreement algorithms. 2. Terminology 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. 3. Updates to Section 3 If the keyUsage extension is present in a certificate that indicates id-ecPublicKey as algorithm of AlgorithmIdentifier [RFC2986] in SubjectPublicKeyInfo, then following values MUST NOT be present: keyEncipherment; and dataEncipherment. If the keyUsage extension is present in a certificate that indicates id-ecDH or id-ecMQV in SubjectPublicKeyInfo, then the following values also MUST NOT be present: keyEncipherment; and dataEncipherment. Ito & Turner Expires February 14, 2020 [Page 2] Internet-Draft Clarifications for ECC SPKI August 2019 4. Security Considerations This document introduces no new security considerations beyond those found in [RFC5480]. 5. IANA Considerations This document makes no request of IANA. 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC2986] Nystrom, M. and B. Kaliski, "PKCS #10: Certification Request Syntax Specification Version 1.7", RFC 2986, DOI 10.17487/RFC2986, November 2000, . [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, . [RFC5480] Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk, "Elliptic Curve Cryptography Subject Public Key Information", RFC 5480, DOI 10.17487/RFC5480, March 2009, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Authors' Addresses Tadahiko Ito SECOM CO., LTD. Email: tadahiko.ito.public@gmail.com Sean Turner sn3rd Email: sean@sn3rd.com Ito & Turner Expires February 14, 2020 [Page 3]