Algorithm Requirements Update to the Internet X.509 Public Key Infrastructure Certificate Request Message Format (CRMF)
draft-housley-lamps-crmf-update-algs-00

Network Working Group                                         R. Housley
Internet-Draft                                            Vigil Security
Updates: 4211 (if approved)                              23 October 2020
Intended status: Standards Track                                        
Expires: 26 April 2021

     Algorithm Requirements Update to the Internet X.509 Public Key
        Infrastructure Certificate Request Message Format (CRMF)
                draft-housley-lamps-crmf-update-algs-00

Abstract

   This document updates the cryptographic algorithm requirements for
   the Password-Based Message Authentication Code in the Internet X.509
   Public Key Infrastructure Certificate Request Message Format (CRMF)
   specified in RFC 4211.

Status of This Memo

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   This Internet-Draft will expire on 26 April 2021.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Password-Based Message Authentication Code  . . . . . . . . .   2
     3.1.  One-Way Function  . . . . . . . . . . . . . . . . . . . .   2
     3.2.  MAC Algorithm . . . . . . . . . . . . . . . . . . . . . .   3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   6.  Normative References  . . . . . . . . . . . . . . . . . . . .   3
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   This document updates the cryptographic algorithm requirements for
   the Password-Based Message Authentication Code (MAC) in the Internet
   X.509 Public Key Infrastructure Certificate Request Message Format
   (CRMF) [RFC4211].  The algorithms specified in [RFC4211] were
   appropriate in 2005; however, these algorithms are no longer
   considered the best choices.  This update specifies algorithms that
   are more appropriate today.

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.  Password-Based Message Authentication Code

   Section 4.4 of [RFC4211] specifies a Password-Based MAC that relies
   on a one-way function to compute a symmetric key from the password
   and a MAC algorithm.  This section specifies algorithm requirements
   for the one-way function and the MAC algorithm.

3.1.  One-Way Function

   Change the paragraph describing the "owf" as follows:

   OLD:

      owf identifies the algorithm and associated parameters used to
      compute the key used in the MAC process.  All implementations MUST
      support SHA-1.

   NEW:

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      owf identifies the algorithm and associated parameters used to
      compute the key used in the MAC process.  All implementations MUST
      support SHA-256 [SHS].

3.2.  MAC Algorithm

   Change the paragraph describing the "mac" as follows:

   OLD:

      mac identifies the algorithm and associated parameters of the MAC
      function to be used.  All implementations MUST support HMAC-SHA1
      [HMAC].  All implementations SHOULD support DES-MAC and Triple-
      DES-MAC [PKCS11].

   NEW:

      mac identifies the algorithm and associated parameters of the MAC
      function to be used.  All implementations MUST support HMAC-SHA256
      [HMAC].  All implementations SHOULD support AES-CMAC [CMAC] with a
      128 bit key.

4.  IANA Considerations

   This document makes no requests of the IANA.

5.  Security Considerations

   Cryptographic algorithms age; they become weaker with time.  As new
   cryptanalysis techniques are developed and computing capabilities
   improve, the work required to break a particular cryptographic
   algorithm will reduce, making an attack on the algorithm more
   feasible for more attackers.  While it is unknown how cryptoanalytic
   attacks will evolve, it is certain that they will get better.  It is
   unknown how much better they will become or when the advances will
   happen.  For this reason, the algorithm requirements for CRMF are
   updated by this specification.

   When a Password-Based MAC is used, implementations must protect the
   password and the MAC key.  Compromise of either the password or the
   MAC key may result in the ability of an attacker to undermine
   authentication.

6.  Normative References

   [AES]      National Institute of Standards and Technology (NIST),
              "Advanced Encryption Standard (AES)", FIPS
              Publication 197, November 2001.

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   [CMAC]     M., D., "Recommendation for Block Cipher Modes of
              Operation: The CMAC Mode for Authentication", NIST Special
              Publication 800-38B, May 2005.

   [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>.

   [RFC4211]  Schaad, J., "Internet X.509 Public Key Infrastructure
              Certificate Request Message Format (CRMF)", RFC 4211,
              DOI 10.17487/RFC4211, September 2005,
              <https://www.rfc-editor.org/info/rfc4211>.

   [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>.

   [SHS]      National Institute of Standards and Technology (NIST),
              "Secure Hash Standard", FIPS Publication 180-4, August
              2015.

Author's Address

   Russ Housley
   Vigil Security, LLC
   516 Dranesville Road
   Herndon, VA,  20170
   United States of America

   Email: housley@vigilsec.com

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