Internet Engineering Task Force (IETF) P. Kampanakis

Internet Engineering Task Force (IETF) P. Kampanakis
Request for Comments: 8692 Cisco Systems
Updates: 3279 Q. Dang
Category: Standards Track NIST
ISSN: 2070-1721 December 2019

Internet X.509 Public Key Infrastructure: Additional Algorithm
Identifiers for RSASSA-PSS and ECDSA Using SHAKEs

Abstract

Digital signatures are used to sign messages, X.509 certificates, and
Certificate Revocation Lists (CRLs). This document updates the
"Algorithms and Identifiers for the Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List (CRL)
Profile" (RFC 3279) and describes the conventions for using the SHAKE
function family in Internet X.509 certificates and revocation lists
as one-way hash functions with the RSA Probabilistic signature and
Elliptic Curve Digital Signature Algorithm (ECDSA) signature
algorithms. The conventions for the associated subject public keys
are also described.

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/rfc8692.

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
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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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.

Table of Contents

1. Introduction
2. Terminology
3. Identifiers
4. Use in PKIX
4.1. Signatures
4.1.1. RSASSA-PSS Signatures
4.1.2. ECDSA Signatures
4.2. Public Keys
5. IANA Considerations
6. Security Considerations
7. References
7.1. Normative References
7.2. Informative References
Appendix A. ASN.1 Module
Acknowledgements
Authors' Addresses

1. Introduction

[RFC3279] defines cryptographic algorithm identifiers for the
"Internet X.509 Public Key Infrastructure Certificate and Certificate
Revocation List (CRL) Profile" [RFC5280]. This document updates RFC
3279 and defines identifiers for several cryptographic algorithms
that use variable-length output SHAKE functions introduced in [SHA3]
which can be used with RFC 5280.

In the SHA-3 family, two extendable-output functions (SHAKEs) are
defined: SHAKE128 and SHAKE256. Four other hash function instances,
SHA3-224, SHA3-256, SHA3-384, and SHA3-512, are also defined but are
out of scope for this document. A SHAKE is a variable-length hash
function defined as SHAKE(M, d) where the output is a d-bits-long
digest of message M. The corresponding collision and second-
preimage-resistance strengths for SHAKE128 are min(d/2, 128) and
min(d, 128) bits, respectively (see Appendix A.1 of [SHA3]). And the
corresponding collision and second-preimage-resistance strengths for
SHAKE256 are min(d/2, 256) and min(d, 256) bits, respectively.

A SHAKE can be used as the message digest function (to hash the
message to be signed) in RSA Probabilistic Signature Scheme (RSASSA-
PSS) [RFC8017] and ECDSA [X9.62] and as the hash in the mask
generation function (MGF) in RSASSA-PSS.

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. Identifiers

This section defines four new object identifiers (OIDs), for RSASSA-
PSS and ECDSA with each of SHAKE128 and SHAKE256. The same algorithm
identifiers can be used for identifying a public key in RSASSA-PSS.

The new identifiers for RSASSA-PSS signatures using SHAKEs are below.

id-RSASSA-PSS-SHAKE128 OBJECT IDENTIFIER ::= { iso(1)
identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) algorithms(6)
30 }

id-RSASSA-PSS-SHAKE256 OBJECT IDENTIFIER ::= { iso(1)
identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) algorithms(6)
31 }

The new algorithm identifiers of ECDSA signatures using SHAKEs are
below.

id-ecdsa-with-shake128 OBJECT IDENTIFIER ::= { iso(1)
identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) algorithms(6)
32 }

id-ecdsa-with-shake256 OBJECT IDENTIFIER ::= { iso(1)
identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) algorithms(6)
33 }

The parameters for the four identifiers above MUST be absent. That
is, the identifier SHALL be a SEQUENCE of one component: the OID.

Sections 4.1.1 and 4.1.2 specify the required output length for each
use of SHAKE128 or SHAKE256 in RSASSA-PSS and ECDSA. In summary,
when hashing messages to be signed, output lengths of SHAKE128 and
SHAKE256 are 256 and 512 bits, respectively. When the SHAKEs are
used as MGFs in RSASSA-PSS, their output length is (8*ceil((n-1)/8) -
264) or (8*ceil((n-1)/8) - 520) bits, respectively, where n is the
RSA modulus size in bits.

4. Use in PKIX

4.1. Signatures

Signatures are used in a number of different ASN.1 structures. As
shown in the ASN.1 representation from [RFC5280] below, in an X.509
certificate, a signature is encoded with an algorithm identifier in
the signatureAlgorithm attribute and a signatureValue attribute that
contains the actual signature.

Certificate ::= SEQUENCE {
tbsCertificate TBSCertificate,
signatureAlgorithm AlgorithmIdentifier,
signatureValue BIT STRING }

The identifiers defined in Section 3 can be used as the
AlgorithmIdentifier in the signatureAlgorithm field in the sequence
Certificate and the signature field in the sequence TBSCertificate in
X.509 [RFC5280]. The parameters of these signature algorithms are
absent, as explained in Section 3.

Conforming Certification Authority (CA) implementations MUST specify
the algorithms explicitly by using the OIDs specified in Section 3
when encoding RSASSA-PSS or ECDSA with SHAKE signatures in
certificates and CRLs. Conforming client implementations that
process certificates and CRLs using RSASSA-PSS or ECDSA with SHAKE
MUST recognize the corresponding OIDs. Encoding rules for RSASSA-PSS
and ECDSA signature values are specified in [RFC4055] and [RFC5480],
respectively.

When using RSASSA-PSS or ECDSA with SHAKEs, the RSA modulus and ECDSA
curve order SHOULD be chosen in line with the SHAKE output length.
Refer to Section 6 for more details.

4.1.1. RSASSA-PSS Signatures

The RSASSA-PSS algorithm is defined in [RFC8017]. When id-RSASSA-
PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256 (specified in Section 3) is
used, the encoding MUST omit the parameters field. That is, the
AlgorithmIdentifier SHALL be a SEQUENCE of one component: id-RSASSA-
PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256. [RFC4055] defines RSASSA-
PSS-params that is used to define the algorithms and inputs to the
algorithm. This specification does not use parameters because the
hash, mask generation algorithm, trailer, and salt are embedded in
the OID definition.

The hash algorithm to hash a message being signed and the hash
algorithm used as the MGF in RSASSA-PSS MUST be the same: both
SHAKE128 or both SHAKE256. The output length of the hash algorithm
that hashes the message SHALL be 32 bytes (for SHAKE128) or 64 bytes
(for SHAKE256).

The MGF takes an octet string of variable length and a desired output
length as input and outputs an octet string of the desired length.
In RSASSA-PSS with SHAKEs, the SHAKEs MUST be used natively as the
MGF, instead of the MGF1 algorithm that uses the hash function in
multiple iterations, as specified in Appendix B.2.1 of [RFC8017]. In
other words, the MGF is defined as the SHAKE128 or SHAKE256 output of
the mgfSeed for id-RSASSA-PSS-SHAKE128 and id-RSASSA-PSS-SHAKE256,
respectively. The mgfSeed is the seed from which the mask is
generated, an octet string [RFC8017]. As explained in Step 9 of
Section 9.1.1 of [RFC8017], the output length of the MGF is emLen -
hLen - 1 bytes. emLen is the maximum message length ceil((n-1)/8),
where n is the RSA modulus in bits. hLen is 32 and 64 bytes for id-
RSASSA-PSS-SHAKE128 and id-RSASSA-PSS-SHAKE256, respectively. Thus,
when SHAKE is used as the MGF, the SHAKE output length maskLen is
(8*emLen - 264) or (8*emLen - 520) bits, respectively. For example,
when RSA modulus n is 2048 bits, the output length of SHAKE128 or
SHAKE256 as the MGF will be 1784 or 1528 bits when id-RSASSA-PSS-
SHAKE128 or id-RSASSA-PSS-SHAKE256 is used, respectively.

The RSASSA-PSS saltLength MUST be 32 bytes for id-RSASSA-PSS-SHAKE128
or 64 bytes for id-RSASSA-PSS-SHAKE256. Finally, the trailerField
MUST be 1, which represents the trailer field with hexadecimal value
0xBC [RFC8017].

4.1.2. ECDSA Signatures

The Elliptic Curve Digital Signature Algorithm (ECDSA) is defined in
[X9.62]. When the id-ecdsa-with-shake128 or id-ecdsa-with-shake256
(specified in Section 3) algorithm identifier appears, the respective
SHAKE function (SHAKE128 or SHAKE256) is used as the hash. The
encoding MUST omit the parameters field. That is, the
AlgorithmIdentifier SHALL be a SEQUENCE of one component: the OID id-
ecdsa-with-shake128 or id-ecdsa-with-shake256.

For simplicity and compliance with the ECDSA standard specification
[X9.62], the output length of the hash function must be explicitly
determined. The output length, d, for SHAKE128 or SHAKE256 used in
ECDSA MUST be 256 or 512 bits, respectively.

Conforming CA implementations that generate ECDSA with SHAKE
signatures in certificates or CRLs SHOULD generate such signatures
with a deterministically generated, nonrandom k in accordance with
all the requirements specified in [RFC6979]. They MAY also generate
such signatures in accordance with all other recommendations in
[X9.62] or [SEC1] if they have a stated policy that requires
conformance to those standards. Those standards have not specified
SHAKE128 and SHAKE256 as hash algorithm options. However, SHAKE128
and SHAKE256 with output length being 32 and 64 octets, respectively,
can be used instead of 256- and 512-bit output hash algorithms such
as SHA256 and SHA512.

4.2. Public Keys

Certificates conforming to [RFC5280] can convey a public key for any
public key algorithm. The certificate indicates the public key
algorithm through an algorithm identifier. This algorithm identifier
is an OID with optionally associated parameters. The conventions and
encoding for RSASSA-PSS and ECDSA public key algorithm identifiers
are as specified in Sections 2.3.1 and 2.3.5 of [RFC3279],
Section 3.1 of [RFC4055] and Section 2.1 of [RFC5480].

Traditionally, the rsaEncryption object identifier is used to
identify RSA public keys. The rsaEncryption object identifier
continues to identify the subject public key when the RSA private key
owner does not wish to limit the use of the public key exclusively to
RSASSA-PSS with SHAKEs. When the RSA private key owner wishes to
limit the use of the public key exclusively to RSASSA-PSS with
SHAKEs, the AlgorithmIdentifiers for RSASSA-PSS defined in Section 3
SHOULD be used as the algorithm field in the SubjectPublicKeyInfo
sequence [RFC5280]. Conforming client implementations that process
RSASSA-PSS with SHAKE public keys when processing certificates and
CRLs MUST recognize the corresponding OIDs.

Conforming CA implementations MUST specify the X.509 public key
algorithm explicitly by using the OIDs specified in Section 3 when
encoding ECDSA with SHAKE public keys in certificates and CRLs.
Conforming client implementations that process ECDSA with SHAKE
public keys when processing certificates and CRLs MUST recognize the
corresponding OIDs.

The identifier parameters, as explained in Section 3, MUST be absent.

5. IANA Considerations

One object identifier for the ASN.1 module in Appendix A has been
assigned in the "SMI Security for PKIX Module Identifier"
(1.3.6.1.5.5.7.0) registry:

+---------+--------------------------+------------+
| Decimal | Description | References |
+=========+==========================+============+
| 94 | id-mod-pkix1-shakes-2019 | RFC 8692 |
+---------+--------------------------+------------+

Table 1

IANA has updated the "SMI Security for PKIX Algorithms"
(1.3.6.1.5.5.7.6) registry [SMI-PKIX] with four additional entries:

+---------+------------------------+------------+
| Decimal | Description | References |
+=========+========================+============+
| 30 | id-RSASSA-PSS-SHAKE128 | RFC 8692 |
+---------+------------------------+------------+
| 31 | id-RSASSA-PSS-SHAKE256 | RFC 8692 |
+---------+------------------------+------------+
| 32 | id-ecdsa-with-shake128 | RFC 8692 |
+---------+------------------------+------------+
| 33 | id-ecdsa-with-shake256 | RFC 8692 |
+---------+------------------------+------------+

Table 2

IANA has updated the "Hash Function Textual Names" registry
[Hash-Texts] with two additional entries for SHAKE128 and SHAKE256:

+--------------------+-------------------------+-----------+
| Hash Function Name | OID | Reference |
+====================+=========================+===========+
| shake128 | 2.16.840.1.101.3.4.2.11 | RFC 8692 |
+--------------------+-------------------------+-----------+
| shake256 | 2.16.840.1.101.3.4.2.12 | RFC 8692 |
+--------------------+-------------------------+-----------+

Table 3

6. Security Considerations

This document updates [RFC3279]. The Security Considerations section
of that document applies to this specification as well.

NIST has defined appropriate use of the hash functions in terms of
the algorithm strengths and expected time frames for secure use in
Special Publications (SPs) [SP800-78-4] and [SP800-107]. These
documents can be used as guides to choose appropriate key sizes for
various security scenarios.

SHAKE128 with output length of 256 bits offers 128 bits of collision
and preimage resistance. Thus, SHAKE128 OIDs in this specification
are RECOMMENDED with 2048- (112-bit security) or 3072-bit (128-bit
security) RSA modulus or curves with group order of 256 bits (128-bit
security). SHAKE256 with a 512-bit output length offers 256 bits of
collision and preimage resistance. Thus, the SHAKE256 OIDs in this
specification are RECOMMENDED with 4096-bit RSA modulus or higher or
curves with a group order of at least 512 bits, such as the NIST
Curve P-521 (256-bit security). Note that we recommended a 4096-bit
RSA because we would need a 15360-bit modulus for 256 bits of
security, which is impractical for today's technology.

7. References

7.1. 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/info/rfc2119>.

[RFC3279] Bassham, L., Polk, W., and R. Housley, "Algorithms and
Identifiers for the Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 3279, DOI 10.17487/RFC3279, April
2002, <https://www.rfc-editor.org/info/rfc3279>.

[RFC4055] Schaad, J., Kaliski, B., and R. Housley, "Additional
Algorithms and Identifiers for RSA Cryptography for use in
the Internet X.509 Public Key Infrastructure Certificate
and Certificate Revocation List (CRL) Profile", RFC 4055,
DOI 10.17487/RFC4055, June 2005,
<https://www.rfc-editor.org/info/rfc4055>.

[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>.

[RFC8017] Moriarty, K., Ed., Kaliski, B., Jonsson, J., and A. Rusch,
"PKCS #1: RSA Cryptography Specifications Version 2.2",
RFC 8017, DOI 10.17487/RFC8017, November 2016,
<https://www.rfc-editor.org/info/rfc8017>.

[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>.

[SHA3] National Institute of Standards and Technology, "SHA-3
Standard: Permutation-Based Hash and Extendable-Output
Functions", DOI 10.6028/NIST.FIPS.202, FIPS PUB 202,
August 2015, <https://doi.org/10.6028/NIST.FIPS.202>.

7.2. Informative References

[Hash-Texts]
IANA, "Hash Function Textual Names",
<https://www.iana.org/assignments/hash-function-text-
names/>.

[RFC5912] Hoffman, P. and J. Schaad, "New ASN.1 Modules for the
Public Key Infrastructure Using X.509 (PKIX)", RFC 5912,
DOI 10.17487/RFC5912, June 2010,
<https://www.rfc-editor.org/info/rfc5912>.

[RFC6979] Pornin, T., "Deterministic Usage of the Digital Signature
Algorithm (DSA) and Elliptic Curve Digital Signature
Algorithm (ECDSA)", RFC 6979, DOI 10.17487/RFC6979, August
2013, <https://www.rfc-editor.org/info/rfc6979>.

[SEC1] Standards for Efficient Cryptography Group, "SEC 1:
Elliptic Curve Cryptography", May 2009,
<http://www.secg.org/sec1-v2.pdf>.

[SMI-PKIX] IANA, "SMI Security for PKIX Algorithms",
<https://www.iana.org/assignments/smi-numbers>.

[SP800-107]
National Institute of Standards and Technology (NIST),
"Recommendation for Applications Using Approved Hash
Algorithms", DOI 10.6028/NIST.SP.800-107r1, Revision 1,
NIST Special Publication (SP) 800-107, August 2012,
<http://dx.doi.org/10.6028/NIST.SP.800-107r1>.

[SP800-78-4]
National Institute of Standards and Technology (NIST),
"Cryptographic Algorithms and Key Sizes for Personal
Identity Verification", DOI 10.6028/NIST.SP.800-78-4, NIST
Special Publication (SP) 800-78-4, May 2015,
<http://dx.doi.org/10.6028/NIST.SP.800-78-4>.

[X9.62] ANSI, "Public Key Cryptography for the Financial Services
Industry: the Elliptic Curve Digital Signature Algorithm
(ECDSA)", ANSI X9.62, 2005.

Appendix A. ASN.1 Module

This appendix includes the ASN.1 module for SHAKEs in X.509. This
module does not come from any previously existing RFC. This module
references [RFC5912].

PKIXAlgsForSHAKE-2019 { iso(1) identified-organization(3) dod(6)
internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkix1-shakes-2019(94) }

DEFINITIONS EXPLICIT TAGS ::=

BEGIN

-- EXPORTS ALL;

IMPORTS

-- FROM RFC 5912

PUBLIC-KEY, SIGNATURE-ALGORITHM, DIGEST-ALGORITHM, SMIME-CAPS
FROM AlgorithmInformation-2009
{ iso(1) identified-organization(3) dod(6) internet(1) security(5)
mechanisms(5) pkix(7) id-mod(0)
id-mod-algorithmInformation-02(58) }

-- FROM RFC 5912

RSAPublicKey, rsaEncryption, pk-rsa, pk-ec,
CURVE, id-ecPublicKey, ECPoint, ECParameters, ECDSA-Sig-Value
FROM PKIXAlgs-2009 { iso(1) identified-organization(3) dod(6)
internet(1) security(5) mechanisms(5) pkix(7) id-mod(0)
id-mod-pkix1-algorithms2008-02(56) }
;

--
-- Message Digest Algorithms (mda-)
--
DigestAlgorithms DIGEST-ALGORITHM ::= {
-- This expands DigestAlgorithms from RFC 5912
mda-shake128 |
mda-shake256,
...
}

--
-- One-Way Hash Functions
--

-- SHAKE128
mda-shake128 DIGEST-ALGORITHM ::= {
IDENTIFIER id-shake128 -- with output length 32 bytes.
}
id-shake128 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
us(840) organization(1) gov(101)
csor(3) nistAlgorithm(4)
hashAlgs(2) 11 }

-- SHAKE256
mda-shake256 DIGEST-ALGORITHM ::= {
IDENTIFIER id-shake256 -- with output length 64 bytes.
}
id-shake256 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16)
us(840) organization(1) gov(101)
csor(3) nistAlgorithm(4)
hashAlgs(2) 12 }

--
-- Public Key (pk-) Algorithms
--
PublicKeys PUBLIC-KEY ::= {
-- This expands PublicKeys from RFC 5912
pk-rsaSSA-PSS-SHAKE128 |
pk-rsaSSA-PSS-SHAKE256,
...
}

-- The hashAlgorithm is mda-shake128
-- The maskGenAlgorithm is id-shake128
-- Mask Gen Algorithm is SHAKE128 with output length
-- (8*ceil((n-1)/8) - 264) bits, where n is the RSA
-- modulus in bits.
-- The saltLength is 32. The trailerField is 1.
pk-rsaSSA-PSS-SHAKE128 PUBLIC-KEY ::= {
IDENTIFIER id-RSASSA-PSS-SHAKE128
KEY RSAPublicKey
PARAMS ARE absent
-- Private key format not in this module --
CERT-KEY-USAGE { nonRepudiation, digitalSignature,
keyCertSign, cRLSign }
}

-- The hashAlgorithm is mda-shake256
-- The maskGenAlgorithm is id-shake256
-- Mask Gen Algorithm is SHAKE256 with output length
-- (8*ceil((n-1)/8) - 520)-bits, where n is the RSA
-- modulus in bits.
-- The saltLength is 64. The trailerField is 1.
pk-rsaSSA-PSS-SHAKE256 PUBLIC-KEY ::= {
IDENTIFIER id-RSASSA-PSS-SHAKE256
KEY RSAPublicKey
PARAMS ARE absent
-- Private key format not in this module --
CERT-KEY-USAGE { nonRepudiation, digitalSignature,
keyCertSign, cRLSign }
}

--
-- Signature Algorithms (sa-)
--
SignatureAlgs SIGNATURE-ALGORITHM ::= {
-- This expands SignatureAlgorithms from RFC 5912
sa-rsassapssWithSHAKE128 |
sa-rsassapssWithSHAKE256 |
sa-ecdsaWithSHAKE128 |
sa-ecdsaWithSHAKE256,
...
}

--
-- SMIME Capabilities (sa-)
--
SMimeCaps SMIME-CAPS ::= {
-- The expands SMimeCaps from RFC 5912
sa-rsassapssWithSHAKE128.&smimeCaps |
sa-rsassapssWithSHAKE256.&smimeCaps |
sa-ecdsaWithSHAKE128.&smimeCaps |
sa-ecdsaWithSHAKE256.&smimeCaps,
...
}

-- RSASSA-PSS with SHAKE128
sa-rsassapssWithSHAKE128 SIGNATURE-ALGORITHM ::= {
IDENTIFIER id-RSASSA-PSS-SHAKE128
PARAMS ARE absent
-- The hashAlgorithm is mda-shake128
-- The maskGenAlgorithm is id-shake128
-- Mask Gen Algorithm is SHAKE128 with output length
-- (8*ceil((n-1)/8) - 264) bits, where n is the RSA
-- modulus in bits.
-- The saltLength is 32. The trailerField is 1
HASHES { mda-shake128 }
PUBLIC-KEYS { pk-rsa | pk-rsaSSA-PSS-SHAKE128 }
SMIME-CAPS { IDENTIFIED BY id-RSASSA-PSS-SHAKE128 }
}
id-RSASSA-PSS-SHAKE128 OBJECT IDENTIFIER ::= { iso(1)
identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) algorithms(6)
30 }

-- RSASSA-PSS with SHAKE256
sa-rsassapssWithSHAKE256 SIGNATURE-ALGORITHM ::= {
IDENTIFIER id-RSASSA-PSS-SHAKE256
PARAMS ARE absent
-- The hashAlgorithm is mda-shake256
-- The maskGenAlgorithm is id-shake256
-- Mask Gen Algorithm is SHAKE256 with output length
-- (8*ceil((n-1)/8) - 520)-bits, where n is the
-- RSA modulus in bits.
-- The saltLength is 64. The trailerField is 1.
HASHES { mda-shake256 }
PUBLIC-KEYS { pk-rsa | pk-rsaSSA-PSS-SHAKE256 }
SMIME-CAPS { IDENTIFIED BY id-RSASSA-PSS-SHAKE256 }
}
id-RSASSA-PSS-SHAKE256 OBJECT IDENTIFIER ::= { iso(1)
identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) algorithms(6)
31 }

-- ECDSA with SHAKE128
sa-ecdsaWithSHAKE128 SIGNATURE-ALGORITHM ::= {
IDENTIFIER id-ecdsa-with-shake128
VALUE ECDSA-Sig-Value
PARAMS ARE absent
HASHES { mda-shake128 }
PUBLIC-KEYS { pk-ec }
SMIME-CAPS { IDENTIFIED BY id-ecdsa-with-shake128 }
}
id-ecdsa-with-shake128 OBJECT IDENTIFIER ::= { iso(1)
identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) algorithms(6)
32 }

-- ECDSA with SHAKE256
sa-ecdsaWithSHAKE256 SIGNATURE-ALGORITHM ::= {
IDENTIFIER id-ecdsa-with-shake256
VALUE ECDSA-Sig-Value
PARAMS ARE absent
HASHES { mda-shake256 }
PUBLIC-KEYS { pk-ec }
SMIME-CAPS { IDENTIFIED BY id-ecdsa-with-shake256 }
}
id-ecdsa-with-shake256 OBJECT IDENTIFIER ::= { iso(1)
identified-organization(3) dod(6) internet(1)
security(5) mechanisms(5) pkix(7) algorithms(6)
33 }

END

Acknowledgements

We would like to thank Sean Turner, Jim Schaad, and Eric Rescorla for
their valuable contributions to this document.

The authors would like to thank Russ Housley for his guidance and
very valuable contributions with the ASN.1 module.

Authors' Addresses

Panos Kampanakis
Cisco Systems

Email: [email protected]

Quynh Dang
NIST
100 Bureau Drive, Stop 8930
Gaithersburg, MD 20899-8930
United States of America

Email: [email protected]