Use of Edwards-Curve Digital Signature Algorithm (EdDSA) Signatures in the Cryptographic Message Syntax (CMS)
RFC 8419
Internet Engineering Task Force (IETF) R. Housley
Request for Comments: 8419 Vigil Security
Category: Standards Track August 2018
ISSN: 2070-1721
Use of Edwards-Curve Digital Signature Algorithm (EdDSA) Signatures
in the Cryptographic Message Syntax (CMS)
Abstract
This document specifies the conventions for using the Edwards-curve
Digital Signature Algorithm (EdDSA) for curve25519 and curve448 in
the Cryptographic Message Syntax (CMS). For each curve, EdDSA
defines the PureEdDSA and HashEdDSA modes. However, the HashEdDSA
mode is not used with the CMS. In addition, no context string is
used with the CMS.
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). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8419.
Copyright Notice
Copyright (c) 2018 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/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.
Housley Standards Track [Page 1]
RFC 8419 Using EdDSA Signatures with CMS August 2018
Table of Contents
1. Introduction ....................................................2
1.1. Terminology ................................................2
1.2. ASN.1 ......................................................2
2. EdDSA Signature Algorithm .......................................3
2.1. Algorithm Identifiers ......................................3
2.2. EdDSA Algorithm Identifiers ................................3
2.3. Message Digest Algorithm Identifiers .......................4
2.4. EdDSA Signatures ...........................................4
3. Signed-data Conventions .........................................5
3.1. Signed-data Conventions with Signed Attributes .............5
3.2. Signed-data Conventions without Signed Attributes ..........6
4. Implementation Considerations ...................................6
5. Security Considerations .........................................6
6. IANA Considerations .............................................7
7. References ......................................................7
7.1. Normative References .......................................7
7.2. Informative References .....................................8
Acknowledgments ....................................................9
Author's Address ...................................................9
1. Introduction
This document specifies the conventions for using the Edwards-curve
Digital Signature Algorithm (EdDSA) [RFC8032] for curve25519
[CURVE25519] and curve448 [CURVE448] with the Cryptographic Message
Syntax (CMS) [RFC5652] signed-data content type. For each curve,
[RFC8032] defines the PureEdDSA and HashEdDSA modes; however, the
HashEdDSA mode is not used with the CMS. In addition, no context
string is used with CMS. EdDSA with curve25519 is referred to as
"Ed25519", and EdDSA with curve448 is referred to as "Ed448". The
CMS conventions for PureEdDSA with Ed25519 and Ed448 are described in
this document.
1.1. 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.
1.2. ASN.1
CMS values are generated using ASN.1 [X680], which uses the Basic
Encoding Rules (BER) and the Distinguished Encoding Rules (DER)
[X690].
Housley Standards Track [Page 2]
RFC 8419 Using EdDSA Signatures with CMS August 2018
2. EdDSA Signature Algorithm
The Edwards-curve Digital Signature Algorithm (EdDSA) [RFC8032] is a
variant of Schnorr's signature system with (possibly twisted) Edwards
Show full document text