LAMPS                                                             T. Ito
Internet-Draft                                           SECOM CO., LTD.
Updates: 5480 (if approved)                                    S. Turner
Intended status: Standards Track                                   sn3rd
Expires: July 11, 2020                                   January 8, 2020


   Clarifications for Elliptic Curve Cryptogtaphy Subject Public Key
                              Information
               draft-ietf-lamps-5480-ku-clarifications-00

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
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   This Internet-Draft will expire on July 11, 2020.

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   document authors.  All rights reserved.

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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.






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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, <https://www.rfc-
              editor.org/info/rfc2119>.

   [RFC2986]  Nystrom, M. and B. Kaliski, "PKCS #10: Certification
              Request Syntax Specification Version 1.7", RFC 2986,
              DOI 10.17487/RFC2986, November 2000, <https://www.rfc-
              editor.org/info/rfc2986>.

   [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,
              <https://www.rfc-editor.org/info/rfc5280>.

   [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,
              <https://www.rfc-editor.org/info/rfc5480>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

Authors' Addresses

   Tadahiko Ito
   SECOM CO., LTD.

   Email: tadahiko.ito.public@gmail.com


   Sean Turner
   sn3rd

   Email: sean@sn3rd.com



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