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draft-ietf-lamps-pkix-shake-07.xml
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draft-ietf-lamps-pkix-shake-07.xml
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<?xml version="1.0" encoding="US-ASCII"?>
<!-- This template is for creating an Internet Draft using xml2rfc,
which is available here: http://xml.resource.org. -->
<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
<!-- One method to get references from the online citation libraries.
There has to be one entity for each item to be referenced.
An alternate method (rfc include) is described in the references. -->
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<!-- <!ENTITY RFC4086 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.4086.xml"> -->
<!ENTITY RFC5280 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.5280.xml">
<!ENTITY RFC5480 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.5480.xml">
<!ENTITY RFC5912 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.5912.xml">
<!ENTITY RFC6979 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.6979.xml">
<!ENTITY RFC8017 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.8017.xml">
<!ENTITY RFC8174 PUBLIC "" "http://xml.resource.org/public/rfc/bibxml/reference.RFC.8174.xml">
<!ENTITY I-D.draft-josefsson-pkix-eddsa SYSTEM "http://xml2rfc.tools.ietf.org/public/rfc/bibxml-ids/reference.I-D.draft-josefsson-pkix-eddsa-04.xml">
]>
<?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?>
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please see http://xml.resource.org/authoring/README.html. -->
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<?rfc symrefs="yes"?>
<!-- use symbolic references tags, i.e, [RFC2119] instead of [1] -->
<?rfc sortrefs="yes" ?>
<!-- sort the reference entries alphabetically -->
<!-- control vertical white space
(using these PIs as follows is recommended by the RFC Editor) -->
<?rfc compact="yes" ?>
<!-- do not start each main section on a new page -->
<?rfc subcompact="no" ?>
<!-- keep one blank line between list items -->
<!-- end of list of popular I-D processing instructions -->
<rfc category="std" docName="draft-ietf-lamps-pkix-shake-07" ipr="trust200902">
<!-- category values: std, bcp, info, exp, and historic
ipr="full3978" (probably old)
ipr values: full3667, noModification3667, noDerivatives3667
you can add the attributes updates="NNNN" and obsoletes="NNNN"
they will automatically be output with "(if approved)" -->
<!-- ***** FRONT MATTER ***** -->
<front>
<!-- The abbreviated title is used in the page header - it is only necessary if the
full title is longer than 39 characters -->
<title abbrev="SHAKE identifiers in X.509">Internet X.509 Public Key Infrastructure: Additional Algorithm Identifiers for RSASSA-PSS and ECDSA using SHAKEs</title>
<!-- add 'role="editor"' below for the editors if appropriate -->
<author fullname="Panos Kampanakis" initials="P.K."
surname="Kampanakis">
<organization>Cisco Systems</organization>
<address>
<email>pkampana@cisco.com</email>
</address>
</author>
<author fullname="Quynh Dang" initials="Q.D."
surname="Dang">
<organization>NIST</organization>
<address>
<postal>
<street>100 Bureau Drive, Stop 8930</street>
<city>Gaithersburg</city>
<region>MD</region>
<code>20899-8930</code>
<country>USA</country>
</postal>
<!-- <phone>+44 7889 488 335</phone> -->
<email>quynh.dang@nist.gov</email>
<!-- uri and facsimile elements may also be added -->
</address>
</author>
<!-- <author fullname="Sean Turner" initials="S.T."
surname="Turner">
<organization>sn3rd</organization>
<address>
<postal>
<street></street>
<city>Soham</city>
<region></region>
<code></code>
<country>UK</country>
</postal>
<phone>+44 7889 488 335</phone>
<email>sean@sn3rd.com</email>
</address>
</author> -->
<date year="2019" />
<!-- If the month and year are both specified and are the current ones, xml2rfc will fill
in the current day for you. If only the current year is specified, xml2rfc will fill
in the current day and month for you. If the year is not the current one, it is
necessary to specify at least a month (xml2rfc assumes day="1" if not specified for the
purpose of calculating the expiry date). With drafts it is normally sufficient to
specify just the year. -->
<!-- Meta-data Declarations -->
<area>General</area>
<workgroup>LAMPS WG</workgroup>
<!-- WG name at the upperleft corner of the doc,
IETF is fine for individual submissions.
If this element is not present, the default is "Network Working Group",
which is used by the RFC Editor as a nod to the history of the IETF. -->
<!-- <keyword>template</keyword> -->
<!-- Keywords will be incorporated into HTML output
files in a meta tag but they have no effect on text or nroff
output. If you submit your draft to the RFC Editor, the
keywords will be used for the searPKIch engine. -->
<abstract>
<t>Digital signatures are used to sign messages, X.509
certificates and CRLs (Certificate Revocation Lists). This
document describes the conventions for using the SHAKE function
family in Internet X.509 certificates and CRLs as one-way hash
functions with the RSA Probabilistic signature and
ECDSA signature algorithms. The conventions for the
associated subject public keys are also described.</t>
</abstract>
</front>
<middle>
<section title="Change Log">
<t>[ EDNOTE: Remove this section before publication. ]</t>
<t><list style="symbols">
<t>draft-ietf-lamps-pkix-shake-07:
<list>
<t>Incorporated Eric's suggestion from WGLC.</t>
</list></t>
<t>draft-ietf-lamps-pkix-shake-06:
<list>
<t>Added informative references.</t>
<t>Updated ASN.1 so it compiles.</t>
<t>Updated IANA considerations.</t>
</list></t>
<t>draft-ietf-lamps-pkix-shake-05:
<list>
<t>Added RFC8174 reference and text.</t>
<t>Explicitly explained why RSASSA-PSS-params are omitted in section 5.1.1.</t>
<t>Simplified Public Keys section by removing redundand info from RFCs.</t>
</list></t>
<t>draft-ietf-lamps-pkix-shake-04:
<list>
<t>Removed paragraph suggesting KMAC to be used in generating k in Deterministric ECDSA. That should be RFC6979-bis. </t>
<t>Removed paragraph from Security Considerations that talks about randomness of k because we are using deterministric ECDSA.</t>
<t>Various ASN.1 fixes.</t>
<t>Text fixes.</t>
</list></t>
<t>draft-ietf-lamps-pkix-shake-03:
<list>
<t>Updates based on suggestions and clarifications by Jim. </t>
<t>Added ASN.1.</t>
</list></t>
<t>draft-ietf-lamps-pkix-shake-02:
<list>
<t>Significant reorganization of the sections to simplify the introduction, the new OIDs and their use in PKIX.</t>
<t>Added new OIDs for RSASSA-PSS that hardcode hash, salt and MGF, according the WG consensus.</t>
<t>Updated Public Key section to use the new RSASSA-PSS OIDs and clarify the algorithm identifier usage.</t>
<t>Removed the no longer used SHAKE OIDs from section 3.1.</t>
<t>Consolidated subsection for message digest algorithms.</t>
<t>Text fixes.</t>
</list></t>
<t>draft-ietf-lamps-pkix-shake-01:
<list>
<t>Changed titles and section names.</t>
<t>Removed DSA after WG discussions.</t>
<t>Updated shake OID names and parameters, added MGF1 section.</t>
<t>Updated RSASSA-PSS section.</t>
<t>Added Public key algorithm OIDs.</t>
<t>Populated Introduction and IANA sections.</t>
</list></t>
<t>draft-ietf-lamps-pkix-shake-00:
<list>
<t>Initial version</t>
</list></t>
</list></t>
</section>
<section title="Introduction">
<t>This document describes cryptographic algorithm identifiers
for several cryptographic algorithms which use variable length output
SHAKE functions introduced in <xref target="SHA3"/> which can be used
with the Internet X.509 Certificate and CRL profile <xref target="RFC5280"/>. </t>
<t>In the SHA-3 family, two extendable-output functions (SHAKEs),
SHAKE128 and SHAKE256, are defined. 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.
And, the corresponding collision and second preimage resistance strengths for SHAKE256
are min(d/2,256) and min(d,256) bits respectively.</t>
<t>A SHAKE can be used as the message digest function (to hash the message to be signed)
in RSASSA-PSS and ECDSA and as the hash in the mask generating function in RSASSA-PSS.
This specification describes the identifiers for SHAKEs to be used in X.509 and their
meaning.</t>
</section>
<!-- This PI places the pagebreak correctly (before the section title) in the text output. -->
<section anchor="terminology" title="Terminology">
<t>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 <xref target="RFC2119"/> <xref target="RFC8174"/>
when, and only when, they appear in all capitals, as shown here.</t>
</section> <!-- Terminology -->
<?rfc needLines="8" ?>
<section title="Identifiers" anchor="oids">
<!-- Commention out the below OIDs as they are no longer pertinent for the below public keys and sigs -->
<!-- The Object Identifiers (OIDs) for these two hash functions are defined in
<xref target="shake-nist-oids"/> and are included here for convenience: </t>
<t><figure><artwork><![CDATA[
id-shake128-len OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
country(16) us(840) organization(1) gov(101) csor(3)
nistalgorithm(4) hashalgs(2) 17 }
ShakeOutputLen ::= INTEGER - - Output length in octets
]]></artwork></figure></t>
<t>When using the id-shake128-len algorithm identifier, the parameters
MUST be present, and they MUST employ the ShakeOutputLen -->
<!-- "MUST employ syntax borrowed from RFC4055 -->
<!-- syntax that contains an encoded positive integer value at least 32
in this specification.</t>
<t><figure><artwork><![CDATA[
id-shake256-len OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
country(16) us(840) organization(1) gov(101) csor(3)
nistalgorithm(4) hashalgs(2) 18 }
ShakeOutputLen ::= INTEGER - - Output length in octets
]]></artwork></figure></t>
<t>When using the id-shake256-len algorithm identifier, the parameters
MUST be present, and they MUST employ the ShakeOutputLen -->
<!-- "MUST employ syntax borrowed from RFC4055 -->
<!-- syntax that contains an encoded positive integer value at least 64
in this specification.</t> -->
<t>This section defines four new OIDs, for RSASSA-PSS and ECDSA with each
of SHAKE-128 and SHAKE-256. The same algorithm identifiers can be
used for identifying a public key in RSASSA-PSS.</t>
<t>The new identifiers for RSASSA-PSS signatures using SHAKEs are below.</t>
<t><figure><artwork><![CDATA[
id-RSASSA-PSS-SHAKE128 OBJECT IDENTIFIER ::= { TBD }
]]></artwork></figure></t>
<t><figure><artwork><![CDATA[
id-RSASSA-PSS-SHAKE256 OBJECT IDENTIFIER ::= { TBD }
[ EDNOTE: "TBD" will be specified by NIST later. ]
]]></artwork></figure></t>
<t>The new algorithm identifiers of ECDSA signatures using SHAKEs are below.</t>
<t><list>
<t><figure><artwork><![CDATA[
id-ecdsa-with-shake128 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
country(16) us(840) organization(1) gov(101)
csor(3) algorithms(4) id-ecdsa-with-shake(3)
TBD }
]]></artwork></figure></t>
<t><figure><artwork><![CDATA[
id-ecdsa-with-shake256 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2)
country(16) us(840) organization(1) gov(101)
csor(3) algorithms(4) id-ecdsa-with-shake(3)
TBD }
[ EDNOTE: "TBD" will be specified by NIST later. ]
]]></artwork></figure></t>
</list></t>
<!-- <xref target="RFC8017"/>, but we include it here as well for convenience:</t>
<t><figure><artwork><![CDATA[
id-mgf1 OBJECT IDENTIFIER ::= { pkcs-1 8 }
]]></artwork></figure>-->
<!-- <t>The parameters field associated with id-mgf1 MUST have a hashAlgorithm value that identifies
the hash used with MGF1. To use SHAKE as this hash, this parameter MUST be
id-shake128-len or id-shake256-len as specified in <xref target="xofs" /> above. </t>-->
<t>The parameters for the four identifiers above MUST be absent. That is,
the identifier SHALL be a SEQUENCE of one component, the OID.</t>
<t><xref target="rsa-sigs"/> and <xref target="ecdsa-sigs"/> 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 mask generation functions RSASSA-PSS, their output length is
(n - 264) or (n - 520) bits respectively, where n is the RSA modulus size in bits.</t>
</section>
<section title="Use in PKIX">
<section title="Signatures" anchor="sigs">
<t>Signatures are used in a number of different ASN.1 structures.
In an X.509 certificate a signature is encoded with an
algorithm identifier in the signatureAlgorithm attribute and
a signatureValue that contains the actual signature.
</t>
<t><figure><artwork><![CDATA[
Certificate ::= SEQUENCE {
tbsCertificate TBSCertificate,
signatureAlgorithm AlgorithmIdentifier,
signatureValue BIT STRING }
]]></artwork></figure></t>
<t>The identifiers defined in <xref target="oids"/> 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.
The parameters of these signature algorithms are absent as explained
in <xref target="oids"/>.
<xref target="RFC5280"/>.</t>
<t>Conforming CA implementations MUST specify the algorithms
explicitly by using the OIDs specified in <xref target="oids"/> when
encoding RSASSA-PSS or ECDSA with SHAKE signatures
in certificates and CRLs.
Conforming client implementations that process RSASSA-PSS or ECDSA
with SHAKE signatures when processing certificates and CRLs
MUST recognize the corresponding OIDs.
Encoding rules for RSASSA-PSS and ECDSA
signature values are specified in <xref target="RFC4055"/> and
<xref target="RFC5480"/> respectively.</t>
<section title="RSASSA-PSS Signatures" anchor="rsa-sigs">
<t>The RSASSA-PSS algorithm is defined in <xref target="RFC8017"/>.
When id-RSASSA-PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256 specified in <xref target="oids"/>
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. <xref target="RFC4055"/>
defines RSASSA-PSS-params that are used to define the algorithms and inputs
to the algorithm. This specification does not use parameters because the
hash and mask generating algorithsm and trailer and salt are embedded in
the OID definition.</t>
<t>The hash algorithm to hash a message being signed and the hash algorithm as the
mask generation function <!-- "MGF(H, emLen - hLen - 1)" <xref target="RFC8017"/> -->
used in RSASSA-PSS MUST be the same, SHAKE128 or SHAKE256 respectively. The
output-length of the hash algorithm which hashes the message SHALL be 32 or
64 bytes respectively. </t>
<t>The mask generation function 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 function, instead of the MGF1 algorithm that uses
the hash function in multiple iterations as specified in Section B.2.1 of
<xref target="RFC8017"/>. In other words, the MGF is defined as
<!-- <t><figure><artwork><![CDATA[
SHAKE128(mgfSeed, maskLen)
]]></artwork></figure>
and
<figure><artwork><![CDATA[
SHAKE256(mgfSeed, maskLen)
]]></artwork></figure></t> -->
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 mask is generated, an octet string <xref target="RFC8017"/>.
As explained in Step 9 of section 9.1.1 of <xref target="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
(n - 264) or (n - 520) bits respectively. For example, when RSA modulus n is 2048,
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. </t>
<t>The RSASSA-PSS saltLength MUST be 32 or 64 bytes respectively.
Finally, the trailerField MUST be 1, which represents
the trailer field with hexadecimal value 0xBC <xref target="RFC8017"/>.</t>
<!-- <t><figure><artwork><![CDATA[
id-RSASSA-PSS OBJECT IDENTIFIER ::= { pkcs-1 k }
RSASSA-PSS-params ::= SEQUENCE {
hashAlgorithm HashAlgorithm,
maskGenAlgorithm MaskGenAlgorithm,
saltLength INTEGER,
trailerField INTEGER }
]]></artwork></figure></t> -->
<!-- <section title="EdDSA with SHAKE">
<t>[ EDNOTE: For the group to decide: pre-hash version or non-prehash version EdDSAs. PureEdDSA, the pre-hashed version of EdDSA, as currently also proposed in draft-ietf-curdle-cms-eddsa-signatures mandates the hash function as SHA512 for Ed25519 and SHAKE256(x,64) for Ed448. The HashEdDSA version of EdDSA does not define the hash. It is up to the WG to go the Pre-hash route which would require an OID that contained the hash. ] </t>
<t>
<list>
<t><figure><artwork><![CDATA[
id-eddsa-with-shake128 OBJECT IDENTIFIER ::= { }
]]></artwork></figure></t>
<t><figure><artwork><![CDATA[
id-eddsa-with-shake256 OBJECT IDENTIFIER ::= { }
]]></artwork></figure></t>
</list></t>
</section> -->
</section>
<section title="ECDSA Signatures" anchor="ecdsa-sigs">
<t>The Elliptic Curve Digital Signature Algorithm (ECDSA) is defined in
<xref target="X9.62"/>. When the id-ecdsa-with-SHAKE128 or id-ecdsa-with-SHAKE256
(specified in <xref target="oids"/>) 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.</t>
<t>For simplicity and compliance with the ECDSA standard specification,
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. </t>
<t>It is RECOMMENDED that conforming CA implementations that generate ECDSA
with SHAKE signatures in certificates or CRLs generate such signatures
with a deterministically generated, non-random k in accordance
with all the requirements specified in <xref target="RFC6979"/>.
<!-- Sections 7.2 and 7.3 of
<xref target="X9.62"/> or with all the requirements specified in Section
4.1.3 of <xref target="SEC1"/>. -->
They MAY also generate such signatures
in accordance with all other recommendations in <xref target="X9.62"/> or
<xref target="SEC1"/> if they have a stated policy that requires
conformance to these standards. These standards may have not specified
SHAKE128 and SHAKE256 as hash algorithm options. However, SHAKE128 and
SHAKE256 with output length being 32 and 64 octets respectively are
subtitutions for 256 and 512-bit output hash algorithms such as SHA256
and SHA512 used in the standards.</t>
<!-- <t>In Section 3.2 "Generation of k" of <xref target="RFC6979"/>, HMAC is used to derive
the deterministic k. Conforming implementations that generate deterministic
ECDSA with SHAKE signatures in X.509 MUST use KMAC with SHAKE128 or KMAC with
SHAKE256 as specfied in <xref target="SP800-185"/> when SHAKE128 or SHAKE256 is
used as the message hashing algorithm, respectively. In this situation, KMAC with
SHAKE128 and KMAC with SHAKE256 have 256-bit and 512-bit outputs respectively,
and the optional customization bit string S is an empty string.</t> -->
</section>
</section>
<section title="Public Keys">
<t>Certificates conforming to <xref target="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 and optionally associated parameters.
The conventions and encoding for RSASSA-PSS and ECDSA <!-- and EdDSA -->
public keys algorithm identifiers are as specified in
Section 2.3 of <xref target="RFC3279"/>,
Section 3.1 of <xref target="RFC4055"/>
and Section 2.1 of <xref target="RFC5480"/>.
<!-- and <xref target="I-D.josefsson-pkix-eddsa"/>--></t>
<t>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 <xref target="oids"/> SHOULD be used as the algorithm
field in the SubjectPublicKeyInfo sequence <xref target="RFC5280"/>.
Conforming client implementations that process RSASSA-PSS
with SHAKE public keys when processing certificates and CRLs MUST
recognize the corresponding OIDs. </t>
<t>Conforming CA implementations MUST specify the X.509 public key
algorithm explicitly by using the OIDs specified in <xref target="oids"/>
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. </t>
<t>The identifier parameters, as explained in section <xref target="oids"/>,
MUST be absent.</t>
</section>
</section>
<section anchor="IANA" title="IANA Considerations">
<t>One object identifier for the ASN.1 module in <xref target="asn"/>
was assigned in the SMI Security for PKIX Module Identifiers
(1.3.6.1.5.5.7.0) registry:
</t>
<t><figure><artwork><![CDATA[
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(TBD) } ]]></artwork></figure></t>
</section>
<section anchor="Security" title="Security Considerations">
<!-- <t>SHAKE128 and SHAKE256 are one-way extensible-output functions. Their output
length depends on a required length of the consumming application. </t> -->
<t>The SHAKEs are deterministic functions. Like any other deterministic function,
executing multiple times with the same input will produce the
same output. Therefore, users should not expect unrelated outputs (with the
same or different output lengths) from running a SHAKE function with the
same input multiple times. The shorter of any two outputs produced from a
SHAKE with the same input is a prefix of the longer one. It is a similar
situation as truncating a 512-bit output of SHA-512 by taking its 256
left-most bits. These 256 left-most bits are a prefix of the 512-bit output.</t>
<t>When using ECDSA with SHAKEs, the ECDSA curve order SHOULD be
chosen in line with the SHAKE output length. 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)
<xref target="SP800-78-4"/> and <xref target="SP800-107"/>.
These documents can be used as guides to choose appropriate key sizes
for various security scenarios. In the context of this document
id-ecdsa-with-shake128 is RECOMMENDED for curves with group order
of 256-bits. id-ecdsa-with-shake256 is RECOMMENDED for curves
with group order of 384-bits or more.</t>
<!-- <t>Implementations must protect the signer's private key. Compromise of
the signer's private key permits masquerade attacks.</t> -->
<!-- <t>Implementations must randomly generate one-time values, such as the k value when generating a ECDSA
signature. In addition, the generation of public/private key pairs
relies on random numbers. The use of inadequate pseudo-random
number generators (PRNGs) to generate such cryptographic values can
result in little or no security. The generation of quality random
numbers is difficult. <xref target="RFC4086"/> offers important guidance
in this area, and <xref target="SP800-90A"/> series provide acceptable
PRNGs.</t> -->
<!-- <t>Implementers should be aware that cryptographic algorithms may
become weaker with time. As new cryptanalysis techniques are developed
and computing power increases, the work factor or time required to break a
particular cryptographic algorithm may decrease. Therefore, cryptographic
algorithm implementations should be modular allowing new algorithms
to be readily inserted. That is, implementers should be prepared to
regularly update the set of algorithms in their implementations.</t> -->
</section>
<!-- Possibly a 'Contributors' section ... -->
<section anchor="Acknowledgements" title="Acknowledgements">
<t>We would like to thank Sean Turner, Jim Schaad and Eric
Rescorla for their valuable contributions to this document.</t>
<t>The authors would like to thank Russ Housley for his guidance and
very valuable contributions with the ASN.1 module.</t>
</section>
</middle>
<!-- *****BACK MATTER ***** -->
<back>
<!-- References split into informative and normative -->
<!-- There are 2 ways to insert reference entries from the citation libraries:
1. define an ENTITY at the top, and use "ampersand character"RFC2629; here (as shown)
2. simply use a PI "less than character"?rfc include="reference.RFC.2119.xml"?> here
(for I-Ds: include="reference.I-D.narten-iana-considerations-rfc2434bis.xml")
Both are cited textually in the same manner: by using xref elements.
If you use the PI option, xml2rfc will, by default, try to find included files in the same
directory as the including file. You can also define the XML_LIBRARY environment variable
with a value containing a set of directories to search. These can be either in the local
filing system or remote ones accessed by http (http://domain/dir/... ).-->
<references title="Normative References">
<!--?rfc include="http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml"?-->
&RFC2119;
&RFC8174;
<!-- &RFC3280; -->
&RFC4055;
&RFC5280;
&RFC5480;
&RFC8017; <!-- RFC8017 is Informational draft but we are keeping it in the Normative References even though idnits complains because we need a normative reference for RSASSA-PSS. RFC4056 does the same thing with RSASS-PSS v2.1 -->
<!-- <?rfc include="http://xml2rfc.tools.ietf.org/public/rfc/bibxml-ids/reference.I-D.draft-josefsson-pkix-eddsa-04.xml"?> -->
<reference anchor="SHA3" target="https://www.nist.gov/publications/sha-3-standard-permutation-based-hash-and-extendable-output-functions">
<front>
<title>SHA-3 Standard - Permutation-Based Hash and Extendable-Output Functions FIPS PUB 202</title>
<author>
<organization>National Institute of Standards and Technology (NIST)</organization>
</author>
<date month="August" year="2015" />
</front>
</reference>
</references>
<references title="Informative References">
<!-- Here we use entities that we defined at the beginning. -->
<!--&RFC2629; -->
&RFC3279;
&RFC5912;
&RFC6979;
<!-- &RFC4086; -->
<!--<reference anchor="shake-nist-oids" target="https://csrc.nist.gov/Projects/Computer-Security-Objects-Register/Algorithm-Registration">
<front>
<title>Computer Security Objects Register</title>
<author>
<organization>National Institute of Standards and Technology</organization>
</author>
<date month="October" year="2017" />
</front>
</reference> -->
<reference anchor="SEC1" target="http://www.secg.org/sec1-v2.pdf">
<front>
<title>SEC 1: Elliptic Curve Cryptography</title>
<author>
<organization>Standards for Efficient Cryptography Group</organization>
</author>
<date month="May" year="2009" />
</front>
</reference>
<reference anchor="X9.62">
<front>
<title>X9.62-2005: Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Standard (ECDSA)</title>
<author>
<organization>American National Standard for Financial Services (ANSI)</organization>
</author>
<date month="November" year="2005" />
</front>
</reference>
<reference anchor="SP800-78-4" target="https://csrc.nist.gov/csrc/media/publications/sp/800-78/4/final/documents/sp800_78-4_revised_draft.pdf">
<front>
<title>SP800-78-4: Cryptographic Algorithms and Key Sizes for Personal Identity Verification</title>
<author>
<organization>National Institute of Standards and Technology (NIST)</organization>
</author>
<date month="May" year="2014" />
</front>
</reference>
<reference anchor="SP800-107" target="https://csrc.nist.gov/csrc/media/publications/sp/800-107/rev-1/final/documents/draft_revised_sp800-107.pdf">
<front>
<title>SP800-107: Recommendation for Applications Using Approved Hash Algorithms</title>
<author>
<organization>National Institute of Standards and Technology (NIST)</organization>
</author>
<date month="May" year="2014" />
</front>
</reference>
<!-- <reference anchor="SP800-90A" target="http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-90Ar1.pdf">
<front>
<title>Recommendation for Random Number Generation Using Deterministic Random Bit Generators. NIST SP 800-90A</title>
<author>
<organization>National Institute of Standards and Technology</organization>
</author>
<date month="June" year="2015" />
</front>
</reference> -->
<!-- <reference anchor="SP800-185" target="http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-185.pdf">
<front>
<title>SHA-3 Derived Functions: cSHAKE, KMAC, TupleHash and ParallelHash. NIST SP 800-185</title>
<author>
<organization>National Institute of Standards and Technology</organization>
</author>
<date month="December" year="2016" />
</front>
</reference> -->
</references>
<section anchor="asn" title="ASN.1 module">
<t>This appendix includes the ASN.1 module for SHAKEs in X.509.
This module does not come from any existing RFC. </t>
<t><figure><artwork><![CDATA[
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(TBD) }
DEFINITIONS EXPLICIT TAGS ::=
BEGIN
-- EXPORTS ALL;
IMPORTS
-- FROM [RFC5912]
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 [RFC5912]
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 [RFC5912]
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 }
-- SHAKE-256
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 [RFC5912]
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
-- (n - 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
-- (n - 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 [RFC5912]
sa-rsassapssWithSHAKE128 |
sa-rsassapssWithSHAKE256 |
sa-ecdsaWithSHAKE128 |
sa-ecdsaWithSHAKE256,
...
}
--
-- SMIME Capabilities (sa-)
--
SMimeCaps SMIME-CAPS ::= {
-- The expands SMimeCaps from [RFC5912]
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
-- (n - 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 ::= { TBD }
-- 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
-- (n - 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 ::= { TBD }
-- Determinstic 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 ::= { joint-iso-itu-t(2)
country(16) us(840) organization(1)
gov(101) csor(3) nistAlgorithm(4)
sigAlgs(3) TBD }
-- Determinstic 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 ::= { joint-iso-itu-t(2)
country(16) us(840) organization(1)
gov(101) csor(3) nistAlgorithm(4)
sigAlgs(3) TBD }
END
]]></artwork></figure>
</t>
</section>
</back>
</rfc>