Internet DRAFT - draft-ietf-lamps-8410-ku-clarifications
draft-ietf-lamps-8410-ku-clarifications
LAMPS S. Turner
Internet-Draft sn3rd
Updates: 8410 (if approved) S. Josefsson
Intended status: Standards Track SJD AB
Expires: 1 January 2023 D. McCarney
Square Inc.
T. Ito
SECOM CO., LTD.
30 June 2022
Clarifications for Ed25519, Ed448, X25519, and X448 Algorithm
Identifiers
draft-ietf-lamps-8410-ku-clarifications-02
Abstract
This document updates RFC 8410 to clarify existing and specify
missing semantics for key usage bits when used in certificates that
support the Ed25519, Ed448, X25519, and X448 Elliptic Curve
Cryptography algorithms.
About This Document
This note is to be removed before publishing as an RFC.
Status information for this document may be found at
https://datatracker.ietf.org/doc/draft-ietf-lamps-8410-ku-
clarifications/.
Source for this draft and an issue tracker can be found at
https://github.com/lamps-wg/8410-ku-clarifications.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 1 January 2023.
Copyright Notice
Copyright (c) 2022 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 (https://trustee.ietf.org/
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Please review these documents carefully, as they describe your rights
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. New Section 5 for RFC 8410 . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 5
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
[RFC8410] specifies the syntax and semantics for the Subject Public
Key Information field in certificates that support Ed25519, Ed448,
X25519, and X448 Elliptic Curve Cryptography (ECC) algorithms. As
part of these semantics, it defines what combinations are permissible
for the values of the key usage extension [RFC5280]. [RFC8410] did
not define what values are not permissible nor did it refer to
keyEncipherment or dataEncipherment. [ERRATA] has also been
submitted to clarify that keyCertSign is always set in certification
authority certificates. To address these changes, this document
replaces Section 5 of [RFC8410] with Section 3.
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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. New Section 5 for RFC 8410
The intended application for the key is indicated in the keyUsage
certificate extension.
If the keyUsage extension is present in a certificate that indicates
id-X25519 or id-X448 in SubjectPublicKeyInfo, then the following MUST
be present:
keyAgreement;
one of the following MAY also be present:
encipherOnly; or
decipherOnly;
and the following MUST NOT be present:
digitalSignature;
nonRepudiation;
keyEncipherment;
dataEncipherment;
keyCertSign; and
cRLSign.
If the keyUsage extension is present in an end-entity certificate
that indicates id-Ed25519 or id-Ed448 in SubjectPublicKeyInfo, then
the keyUsage extension MUST contain at least one of the following:
nonRepudiation;
digitalSignature; and
cRLSign;
and the following MUST NOT be present:
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keyEncipherment;
dataEncipherment;
keyAgreement;
keyCertSign;
encipherOnly; and
decipherOnly.
If the keyUsage extension is present in a CRL issuer certificate that
indicates id-Ed25519 or id-Ed448 in SubjectPublicKeyInfo, then the
keyUsage extension MUST contain:
~~ cRLSign; ~~
and zero or more of the following:
~~ nonRepudiation; and digitalSignature; ~~
and the following MUST NOT be present:
~~ keyEncipherment; dataEncipherment; keyAgreement; encipherOnly; and
decipherOnly; ~~
and if the CRL issuer is also a certification authority, then the
keyUsage extension MUST also contain:
~~ keyCertSign. ~~
If the keyUsage extension is present in a certification authority
certificate that indicates id-Ed25519 or id-Ed448 in
SubjectPublicKeyInfo, then the keyUsage extension MUST contain:
keyCertSign
and zero or more of the following:
nonRepudiation;
digitalSignature; and
cRLSign;
and the following MUST NOT be present:
keyEncipherment;
dataEncipherment;
keyAgreement;
encipherOnly; and
decipherOnly.
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4. Security Considerations
This document introduces no new security considerations beyond those
found in [RFC8410].
5. IANA Considerations
This document has no IANA actions.
6. References
6.1. 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/rfc/rfc2119>.
[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/rfc/rfc5280>.
[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/rfc/rfc8174>.
[RFC8410] Josefsson, S. and J. Schaad, "Algorithm Identifiers for
Ed25519, Ed448, X25519, and X448 for Use in the Internet
X.509 Public Key Infrastructure", RFC 8410,
DOI 10.17487/RFC8410, August 2018,
<https://www.rfc-editor.org/rfc/rfc8410>.
6.2. Informative References
[ERRATA] Liao, L., "Errata 5696", 17 April 2019,
<https://www.rfc-editor.org/errata/eid5696>.
Acknowledgments
We would like to thank Russ Housley, Mike Jenkins, and Corey Bonnell
for the comments.
Authors' Addresses
Sean Turner
sn3rd
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Email: sean@sn3rd.com
Simon Josefsson
SJD AB
Email: simon@josefsson.org
Daniel McCarney
Square Inc.
Email: daniel@binaryparadox.net
Tadahiko Ito
SECOM CO., LTD.
Email: tadahiko.ito.public@gmail.com
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