--- 1/draft-ietf-lamps-pkix-shake-08.txt 2019-04-11 21:13:30.303372090 -0700 +++ 2/draft-ietf-lamps-pkix-shake-09.txt 2019-04-11 21:13:30.339373034 -0700 @@ -1,20 +1,20 @@ LAMPS WG P. Kampanakis Internet-Draft Cisco Systems -Intended status: Standards Track Q. Dang -Expires: August 4, 2019 NIST - January 31, 2019 +Updates: RFC3279 (if approved) Q. Dang +Intended status: Standards Track NIST +Expires: October 13, 2019 April 11, 2019 Internet X.509 Public Key Infrastructure: Additional Algorithm Identifiers for RSASSA-PSS and ECDSA using SHAKEs - draft-ietf-lamps-pkix-shake-08 + draft-ietf-lamps-pkix-shake-09 Abstract 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. @@ -27,21 +27,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on August 4, 2019. + This Internet-Draft will expire on October 13, 2019. 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 @@ -49,39 +49,47 @@ 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. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 4. Identifiers . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 5. Use in PKIX . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 5.1. Signatures . . . . . . . . . . . . . . . . . . . . . . . 5 + 4. Identifiers . . . . . . . . . . . . . . . . . . . . . . . . . 5 + 5. Use in PKIX . . . . . . . . . . . . . . . . . . . . . . . . . 6 + 5.1. Signatures . . . . . . . . . . . . . . . . . . . . . . . 6 5.1.1. RSASSA-PSS Signatures . . . . . . . . . . . . . . . . 6 5.1.2. ECDSA Signatures . . . . . . . . . . . . . . . . . . 7 - 5.2. Public Keys . . . . . . . . . . . . . . . . . . . . . . . 7 + 5.2. Public Keys . . . . . . . . . . . . . . . . . . . . . . . 8 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 - 7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 9 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 9.1. Normative References . . . . . . . . . . . . . . . . . . 9 9.2. Informative References . . . . . . . . . . . . . . . . . 10 Appendix A. ASN.1 module . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 1. Change Log [ EDNOTE: Remove this section before publication. ] + o draft-ietf-lamps-cms-shake-09: + + * Fixed minor text nits. + + * Added text name allocation for SHAKEs in IANA considerations. + + * Updates in Sec Considerations section. + o draft-ietf-lamps-pkix-shake-08: * Small nits from Russ while in WGLC. o draft-ietf-lamps-pkix-shake-07: * Incorporated Eric's suggestion from WGLC. o draft-ietf-lamps-pkix-shake-06: @@ -91,30 +99,30 @@ * Updated IANA considerations. o draft-ietf-lamps-pkix-shake-05: * Added RFC8174 reference and text. * Explicitly explained why RSASSA-PSS-params are omitted in section 5.1.1. - * Simplified Public Keys section by removing redundand info from + * Simplified Public Keys section by removing redundant info from RFCs. o draft-ietf-lamps-pkix-shake-04: * Removed paragraph suggesting KMAC to be used in generating k in - Deterministric ECDSA. That should be RFC6979-bis. + Deterministic ECDSA. That should be RFC6979-bis. * Removed paragraph from Security Considerations that talks about - randomness of k because we are using deterministric ECDSA. + randomness of k because we are using deterministic ECDSA. * Various ASN.1 fixes. * Text fixes. o draft-ietf-lamps-pkix-shake-03: * Updates based on suggestions and clarifications by Jim. * Added ASN.1. @@ -181,46 +189,45 @@ 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. 4. Identifiers This section defines four new object identifiers (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. + 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 ::= { TBD } + id-RSASSA-PSS-SHAKE128 OBJECT IDENTIFIER ::= { TBD1 } - id-RSASSA-PSS-SHAKE256 OBJECT IDENTIFIER ::= { TBD } + id-RSASSA-PSS-SHAKE256 OBJECT IDENTIFIER ::= { TBD2 } - [ EDNOTE: "TBD" will be specified by NIST later. ] + [ EDNOTE: "TBD1", "TBD2" will be specified by NIST later. ] The new algorithm identifiers of ECDSA signatures using SHAKEs are below. 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 } + TBD3 } 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 } + TBD4 } - [ EDNOTE: "TBD" will be specified by NIST later. ] + [ EDNOTE: "TBD3", "TBD4" will be specified by NIST later. ] The parameters for the four identifiers above MUST be absent. That is, the identifier SHALL be a SEQUENCE of one component, the OID. Section 5.1.1 and Section 5.1.2 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 mask generation functions RSASSA-PSS, their output length is (n - 264) or (n - 520) bits respectively, where n is the @@ -248,41 +255,48 @@ Conforming CA implementations MUST specify the algorithms explicitly by using the OIDs specified in Section 4 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 [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. + In the context of this document SHAKE128 OIDs are RECOMMENDED for + 2048 or 3072-bit RSA modulus or curves with group order of 256-bits. + SHAKE256 OIDs are RECOMMENDED for 4096-bit RSA modulus and higher or + curves with group order of 384-bits and higher. + 5.1.1. RSASSA-PSS Signatures The RSASSA-PSS algorithm is defined in [RFC8017]. When id-RSASSA- PSS-SHAKE128 or id-RSASSA-PSS-SHAKE256 specified in Section 4 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 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 + hash and mask generating algorithm and trailer and salt are embedded in the OID definition. The hash algorithm to hash a message being signed and the hash algorithm as the mask generation function 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. 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 + 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 [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 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 @@ -292,42 +306,42 @@ 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 or 64 bytes respectively. Finally, the trailerField MUST be 1, which represents the trailer field with hexadecimal value 0xBC [RFC8017]. 5.1.2. 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 + [X9.62]. When the id-ecdsa-with-shake128 or id-ecdsa-with-shake256 (specified in Section 4) 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. + ecdsa-with-shake128 or id-ecdsa-with-shake256. 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. 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 [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 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 + octets respectively are substitutions for 256 and 512-bit output hash algorithms such as SHA256 and SHA512 used in the standards. 5.2. 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 and optionally associated parameters. The conventions and encoding for RSASSA-PSS and ECDSA public keys algorithm identifiers are as specified in Section 2.3 of [RFC3279], Section 3.1 of @@ -358,59 +372,65 @@ 6. IANA Considerations One object identifier for the ASN.1 module in Appendix A was assigned in the SMI Security for PKIX Module Identifiers (1.3.6.1.5.5.7.0) registry: 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) } + IANA is also requested to update 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 | [ THIS RFC ] | + | shake256 | 2.16.840.1.101.3.4.2.12 | [ THIS RFC ] | + +--------------------+-------------------------+--------------+ + 7. Security Considerations - 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. + This document updates [RFC3279]. The security considerations section + of that document applies to this specification as well. - 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) - [SP800-78-4] and [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. + 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. 8. 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. 9. References 9.1. 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, . + [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, . + [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, . [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 @@ -432,25 +452,24 @@ May 2017, . [SHA3] National Institute of Standards and Technology (NIST), "SHA-3 Standard - Permutation-Based Hash and Extendable- Output Functions FIPS PUB 202", August 2015, . 9.2. Informative References - [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, . + [Hash-Texts] + IANA, "Hash Function Textual Names", July 2017, + . [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, . [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, . @@ -528,21 +547,21 @@ -- 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 + -- 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 @@ -615,65 +635,65 @@ -- 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 } + id-RSASSA-PSS-SHAKE128 OBJECT IDENTIFIER ::= { TBD1 } -- 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 } + id-RSASSA-PSS-SHAKE256 OBJECT IDENTIFIER ::= { TBD2 } - -- Determinstic ECDSA with SHAKE128 + -- Deterministic 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 } + sigAlgs(3) TBD3 } - -- Determinstic ECDSA with SHAKE256 + -- Deterministic 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 } + sigAlgs(3) TBD4 } END Authors' Addresses Panos Kampanakis Cisco Systems Email: pkampana@cisco.com