PKIXNetwork Working Group Q. Dang(NIST) Internet DraftRequest for Comments: 5758 NIST Updates: 3279 S. SantessonIntendedCategory: Standards Track 3xA Security(AAA-sec.com)K.Moriarty(RSA)Moriarty RSA D. Brown(Certicom Corp.)Certicom Corp. T. Polk(NIST) October 07,NIST December 2009Expires: April 07, 2010Internet X.509 Public Key Infrastructure: Additional Algorithms and Identifiers for DSA and ECDSA<draft-ietf-pkix-sha2-dsa-ecdsa-10.txt>Abstract This document updates RFC 3279 to specify algorithm identifiers and ASN.1 encoding rules for the Digital Signature Algorithm (DSA) and Elliptic Curve Digital Signature Algorithm (ECDSA) digital signatures when using SHA-224, SHA-256,SHA-384SHA-384, or SHA-512 as the hashing algorithm. This specification applies to the Internet X.509 Public Key infrastructure (PKI) when digital signatures are used to sign certificates and certificate revocationlists(CRLs).lists (CRLs). This document also identifies all four SHA2 hash algorithms for use in the Internet X.509 PKI. Status ofthisThis Memo ThisInternet-Draft is submitted to IETF in full conformance withdocument specifies an Internet standards track protocol for theprovisions of BCP 78Internet community, andBCP 79. Internet-Drafts are working documentsrequests discussion and suggestions for improvements. Please refer to the current edition of theInternet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid"Internet Official Protocol Standards" (STD 1) fora maximum of six monthsthe standardization state andmay 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." The liststatus ofcurrent Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The listthis protocol. Distribution ofInternet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 07, 2010.this memo is unlimited. Copyright Notice Copyright (c) 2009 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of thisdocument (http://trustee.ietf.org/license-info).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 BSD License. Table of Contents 1.Introduction.............................................2Introduction ....................................................2 2. HashFunctions...........................................3Functions ..................................................2 3. SignatureAlgorithms.....................................3 3.1Algorithms ............................................3 3.1. DSA SignatureAlgorithm.................................4 3.2Algorithm ....................................3 3.2. ECDSA SignatureAlgorithm...............................4Algorithm ..................................4 4. ASN.1Module.............................................5Module ....................................................5 5. SecurityConsiderations..................................6Considerations .........................................5 6.References...............................................6 6.1References ......................................................6 6.1. Normativereferences: ..................................6 6.2References .......................................6 6.2. Informativereferences: ................................7References .....................................6 7.Authors' Addresses.......................................7 8. IANA Considerations......................................8 9. Acknowledgement..........................................8Acknowledgements ................................................7 1. Introduction This specification defines the contents of the signatureAlgorithm,signatureValuesignatureValue, and signature fields within Internet X.509 certificates and CRLs when these objects are signed using DSA or ECDSA with a SHA2 hash algorithm. These fields are more fully described in RFC 5280[RFC 5280].[RFC5280]. This document also identifies all four SHA2 hash algorithms for use in the Internet X.509 PKI. This document profiles material presented in the "Secure Hash Standard"[FIPS 180-3],[FIPS180-3], "Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Standard (ECDSA)" [X9.62], and the "Digital Signature Standard"[FIPS 186-3].[FIPS186-3]. This document updates RFC 3279[RFC 3279] sections[RFC3279] Sections 2.1, 2.2.2, and 2.2.3. Note that RFC 5480[RFC 5480][RFC5480] updatessectionsSections 2.3.5, 3 (ASN.1Module)Module), and 5 (Security Considerations) of RFC 3279. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in[RFC 2119].[RFC2119]. 2. Hash Functions This section identifies four additional hash algorithms for use with DSA and ECDSA in the Internet X.509 certificate and CRL profile[RFC 5280].[RFC5280]. SHA-224, SHA-256, SHA-384, and SHA-512 produce a 224-bit, 256-bit,384-bit384-bit, and 512-bit "hash" of theinput respectivelyinput, respectively, and are fully described in the Federal Information Processing Standard 180-3[FIPS 180-3].[FIPS180-3]. The listed one-way hash functions are identified by the following object identifiers (OIDs): id-sha224 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3) nistalgorithm(4) hashalgs(2) 4 } id-sha256 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3) nistalgorithm(4) hashalgs(2) 1 } id-sha384 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3) nistalgorithm(4) hashalgs(2) 2 } id-sha512 OBJECT IDENTIFIER ::= { joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3) nistalgorithm(4) hashalgs(2) 3 } When one of these OIDs appears in an AlgorithmIdentifier, all implementations MUST accept both NULL and absent parameters as legal and equivalent encodings. ConformingCAcertification authority (CA) implementations SHOULD use SHA-224, SHA-256,SHA-384SHA-384, or SHA-512 when generating certificates or CRLs, but MAY use SHA-1 if they have a stated policy that requires the use of this weaker algorithm. 3. Signature Algorithms This section identifies OIDs for DSA with SHA-224 and SHA-256 as well as ECDSA with SHA-224, SHA-256, SHA-384, and SHA-512. The contents of the parameters component for each signature algorithm vary; details are provided for each algorithm.3.13.1. DSA Signature Algorithm The DSA is defined in the Digital Signature Standard (DSS)[FIPS 186-3].[FIPS186-3]. DSA was developed by the U.S. Government, and can be used in conjunction with a SHA2 hash function such as SHA-224 or SHA-256. DSA is fully described in[FIPS 186-3].[FIPS186-3]. When SHA-224 is used, the OID is: id-dsa-with-sha224 OBJECT IDENTIFIER ::= { joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101) csor(3) algorithms(4) id-dsa-with-sha2(3) 1 }. When SHA-256 is used, the OID is: id-dsa-with-sha256 OBJECT IDENTIFIER ::= { joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101) csor(3) algorithms(4) id-dsa-with-sha2(3) 2 }. When the id-dsa-with-sha224 or id-dsa-with-sha256 algorithm identifier appears in the algorithm field as an AlgorithmIdentifier, the encoding SHALL omit the parameters field. That is, the AlgorithmIdentifier SHALL be a SEQUENCE of one component, the OID id-dsa-with-sha224 or id-dsa-with-sha256. Encoding rules for DSA signature values are specified in[RFC 3279].[RFC3279]. Conforming CA implementations that generate DSA signatures for certificates or CRLs MUST generate such DSA signatures in accordance with all the requirements in Sections 4.1,4.54.5, and 4.6 of[FIPS 186-3].[FIPS186-3]. Conforming CA implementations that generate DSA signatures for certificates or CRLs MAY generate such DSA signatures in accordance with all the requirements and recommendations in[FIPS 186-3],[FIPS186-3], if they have a stated policy that requires conformance to[FIPS 186-3]. 3.2[FIPS186-3]. 3.2. ECDSA Signature Algorithm The Elliptic Curve Digital Signature Algorithm (ECDSA) is defined in "Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Standard (ECDSA)" [X9.62]. The ASN.1 OIDs used to specify that an ECDSA signature was generated using SHA-224, SHA-256,SHA-384SHA-384, or SHA-512areare, respectively: ecdsa-with-SHA224 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 1 } ecdsa-with-SHA256 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 2 } ecdsa-with-SHA384 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 3 } ecdsa-with-SHA512 OBJECT IDENTIFIER ::= { iso(1) member-body(2) us(840) ansi-X9-62(10045) signatures(4) ecdsa-with-SHA2(3) 4 } When the ecdsa-with-SHA224, ecdsa-with-SHA256,ecdsa-with-SHA384ecdsa-with-SHA384, or ecdsa-with-SHA512 algorithm identifier appears in the algorithm field as an AlgorithmIdentifier, the encoding MUST omit the parameters field. That is, the AlgorithmIdentifier SHALL be a SEQUENCE of one component, the OID ecdsa-with-SHA224, ecdsa-with-SHA256, ecdsa-with-SHA256, ecdsa-with-SHA384SHA384, or ecdsa-with-SHA512. Conforming CA implementations MUST specify the hash algorithm explicitly using the OIDs specified above when encoding ECDSA/SHA2 signatures in certificates and CRLs. Conforming client implementations that process ECDSA signatures with any of the SHA2 hash algorithms when processing certificates and CRLs MUST recognize the corresponding OIDs specified above. Encoding rules for ECDSA signature values are specified in RFC 3279[RFC 3279][RFC3279], Section2.2.32.2.3, and RFC 5480[RFC 5480].[RFC5480]. Conforming CA implementations that generate ECDSA signatures in certificates or CRLs MUST generate such ECDSA signatures in accordance with all the requirements specified in Sections 7.2 and 7.3 of [X9.62] or with all the requirements specified in Section 4.1.3 of [SEC1]. Conforming CA implementations that ECDSA signatures in certificates or CRLs MAY generate such ECDSA signatures in accordance with all the requirements and recommendations in [X9.62] or [SEC1] if they have a stated policy that requires conformance to [X9.62] or [SEC1]. 4. ASN.1 Module The OIDs of the SHA2 hash algorithms are in the RFC 4055[RFC 4055][RFC4055] ASN.1 module and the OIDs for DSA with SHA-224 and SHA-256 as well as ECDSA with SHA-224, SHA-256,SHA-384SHA-384, and SHA-512 are defined in the RFC 5480[RFC 5480][RFC5480] ASN.1 module. 5. Security Considerations 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) 800-78-1[SP 800-78-1],[SP800-78-1], 800-57[SP 800- 57][SP800-57], and 800-107[SP 800-107].[SP800-107]. These documents can be used as guides to choose appropriate key sizes for various security scenarios. ANSI also provides security considerations for ECDSA in [X9.62]. These security considerations may be used as a guide. 6. References6.16.1. Normativereferences: [RFC 2119]References [RFC2119] Bradner, S., "KeyWordswords forUseuse in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.[RFC 3279][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, April 2002.[RFC 4055][RFC4055] Schaad, J., Kaliski, B., and R. Housley,R.,"Additional"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, June 2005.[RFC 5480][RFC5480] Turner, S.,BrownBrown, D.,YiuYiu, K.,Housley R.,and Polk,T.,Housley, R., and T. Polk, "Elliptic Curve Cryptography Subject Public Key Information", RFC 5480, March 2009.[RFC 5280][RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen,S.S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, May 2008.[FIPS 180-3][FIPS180-3] Federal Information Processing Standards Publication (FIPS PUB) 180-3, Secure Hash Standard (SHS), October 2008.[FIPS 186-3][FIPS186-3] Federal Information Processing Standards Publication (FIPS PUB) 186-3, Digital Signature Standard (DSS), June 2009. [SEC1] Standards for Efficient Cryptography Group (SECG), SEC 1: Elliptic Curve Cryptography, Version 2.0, 2009. [X9.62] X9.62-2005, "Public Key Cryptography for the Financial Services Industry: The Elliptic Curve Digital Signature Standard (ECDSA)", November, 2005.6.26.2. Informativereferences: [SP 800-107]References [SP800-107] Quynh Dang, NIST, "Recommendation for Applications Using Approved Hash Algorithms", February 2009.[SP 800-78-1][SP800-78-1] W. Timothy Polk, Donna, F. Dodson, William E. Burr, NIST, "Cryptographic Standards and Key Sizes for Personal Identity Verification", August 2007.[SP 800-57][SP800-57] Elaine Barker, William Barker, William E. Burr, NIST, "Recommendation for Key Management", August 2005. 7. Acknowledgements The authors of this document would like to acknowledge great inputs for this document from Alfred Hoenes, Sean Turner, Katrin Hoeper, and many others from IETF community. The authors also appreciate many great revision suggestions from Russ Housley and Paul Hoffman. Authors'addressesAddresses Quynh Dang NIST 100 Bureau Drive, Stop 8930 Gaithersburg, MD 20899-8930 USAEmail:EMail: quynh.dang@nist.gov Stefan Santesson 3xA Security (AAA-sec.com) Bjornstorp 744 247 98 Genarp Sweden EMail: sts@aaa-sec.com Kathleen M. Moriarty RSA, The Security Division of EMC 174 Middlesex Turnpike Bedford, MA 01730Email:USA EMail: Moriarty_Kathleen@emc.com Daniel R. L. Brown Certicom Corp. 5520 Explorer Drive Mississaug, ON L4W 5L1Email:USA EMail: dbrown@certicom.com Tim Polk NIST 100 Bureau Drive, Stop 8930 Gaithersburg, MD 20899-8930 USAEmail:EMail: tim.polk@nist.gov8. IANA Considerations This document has no actions for IANA. 9. Acknowledgement Authors of this document would like to acknowledge great inputs for this document from Alfred Hoenes, Sean Turner, Katrin Hoeper and many others from IETF community. The authors also appreciate many great revision suggestions from Russ Housley and Paul Hoffman.