[Docs] [txt|pdf] [Tracker] [Email] [Nits]

Versions: 00

Network Working Group                                          K. Burgin
Internet-Draft                                               A. Hennessy
Intended status: Informational                  National Security Agency
Expires: September 6, 2012                                 March 5, 2012


            Suite B Profile for the Bundle Security Protocol
                  draft-hennessy-bsp-suiteb-profile-00

Abstract

   The United States Government has published guidelines for "NSA Suite
   B Cryptography" dated July, 2005, which defines cryptographic
   algorithm policy for national security applications.  This document
   specifies the conventions for using Suite B cryptography in the
   Bundle Security Protocol (BSP)

   Since many of the Suite B algorithms enjoy uses in other environments
   as well, the majority of the conventions needed for the Suite B
   algorithms are already specified in other documents.  This document
   references the source of these conventions, with some relevant
   details repeated to aid developers that choose to support Suite B.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   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 http://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 September 6, 2012.

Copyright Notice

   Copyright (c) 2012 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



Burgin & Hennessy       Expires September 6, 2012               [Page 1]

Internet-Draft           Suite B Profile for BSP              March 2012


   publication of this 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 Simplified BSD License.


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . . . 3
   3.  Suite B Requirements  . . . . . . . . . . . . . . . . . . . . . 3
   4.  Minimum Levels of Security (minLOS) . . . . . . . . . . . . . . 4
     4.1.  Non-signature Primitives  . . . . . . . . . . . . . . . . . 4
     4.2.  Suite B Authentication  . . . . . . . . . . . . . . . . . . 4
     4.3.  Digital Signatures and Certificates . . . . . . . . . . . . 5
   5.  Suite B Ciphersuites  . . . . . . . . . . . . . . . . . . . . . 5
   6.  Security Considerations . . . . . . . . . . . . . . . . . . . . 6
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     8.1.  Normative References  . . . . . . . . . . . . . . . . . . . 7
     8.2.  Informative References  . . . . . . . . . . . . . . . . . . 8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 8



























Burgin & Hennessy       Expires September 6, 2012               [Page 2]

Internet-Draft           Suite B Profile for BSP              March 2012


1.  Introduction

   This document specifies the conventions for using NSA Suite B
   Cryptography [SuiteB] in the Bundle Security Protocol (BSP).

   The Bundle Security Protocol (BSP) provides source authentication,
   data integrity, and data confidentiality services for the Bundle
   Protocol.

   [SuiteB-suites] defines eight ciphersuites for BSP that are comprised
   of Suite B algorithms for use with the security block types BAB, PIB,
   PCB, and ESB.  Suite B compliant implementations for BSP MUST use one
   of these eight ciphersuites depending upon the desired security level
   and security services.


2.  Requirements Language

   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 [RFC2119].


3.  Suite B Requirements

   Suite B requires that key establishment and signature algorithms be
   based upon Elliptic Curve Cryptography and that the encryption
   algorithm be AES [FIPS197].  Suite B includes [SuiteB]:

      Encryption:         Advanced Encryption Standard (AES) [FIPS197]
                          (key sizes of 128 and 256 bits)

      Digital Signature:  Elliptic Curve Digital Signature Algorithm
                          (ECDSA) [FIPS186-3] (using the curves with
                          256- and 384-bit prime moduli)

      Key Exchange:       Elliptic Curve Diffie-Hellman (ECDH)
                          [SP800-56A] (using the curves with 256- and
                          384-bit prime moduli)

      Hashes:             SHA-256 and SHA-384 [FIPS180-3]

   The two elliptic curves used in Suite B appear in the literature
   under two different names.  For sake of clarity, we list both names
   below:






Burgin & Hennessy       Expires September 6, 2012               [Page 3]

Internet-Draft           Suite B Profile for BSP              March 2012


         Curve       NIST Name    SECG Name    OID  [FIPS186-3]
         ---------------------------------------------------------
         P-256       nistp256     secp256r1    1.2.840.10045.3.1.7
         P-384       nistp384     secp384r1    1.3.132.0.34


4.  Minimum Levels of Security (minLOS)

   Suite B provides for two levels of cryptographic security, namely a
   128-bit minimum level of security (minLOS_128) and a 192-bit minimum
   level of security (minLOS_192).  Each level defines a minimum
   strength that all cryptographic algorithms must provide.

4.1.  Non-signature Primitives

   We divide the Suite B non-signature primitives into two columns as
   shown in Table 1.

                               Column 1            Column 2
                          +-------------------+-------------------+
         Encryption       |  AES-128          |  AES-256          |
                          +-------------------+-------------------+
         Key Agreement    |  ECDH on P-256    |  ECDH on P-384    |
                          +-------------------+-------------------+
         Key Wrap         |  AES-128 Key Wrap |  AES-256 Key Wrap |
                          +-------------------+-------------------+
         Hash for PRF/MAC |  SHA-256          |  SHA-384          |
                          +-------------------+-------------------+


          Table 1: Suite B Cryptographic Non-Signature Primitives

   At the 128-bit minimum level of security:

   o  the non-signature primitives MUST either come exclusively from
      Column 1 or exclusively from Column 2, with Column 1 being the
      preferred suite.

   At the 192-bit minimum level of security:

   o  the non-signature primitives MUST come exclusively from Column 2.

4.2.  Suite B Authentication

   Digital signatures using ECDSA MUST be used for authentication by
   Suite B compliant BSP implementations.  To simplify notation, ECDSA-
   256 will be used to represent an instantiation of the ECDSA algorithm
   using the P-256 curve and the SHA-256 hash function, and ECDSA-384



Burgin & Hennessy       Expires September 6, 2012               [Page 4]

Internet-Draft           Suite B Profile for BSP              March 2012


   will be used to represent an instantiation of the ECDSA algorithm
   using the P-384 curve and the SHA-384 hash function.

   If configured at a minimum level of security of 128 bits, a Suite B
   compliant BSP implementation MUST use either ECDSA-256 or ECDSA-384
   for authentication.  It is allowable for one party to authenticate
   with ECDSA-256 and the other party to authenticate with ECDSA-384.
   This flexibility will allow interoperability between a security
   source and a security destination that have different sizes of ECDSA
   authentication keys.

   Security-aware nodes in a Suite B compliant BSP implementation
   configured at a minimum level of security of 128 bits MUST be able to
   verify ECDSA-256 signatures and SHOULD be able to verify ECDSA-384
   signatures unless it is absolutely certain that the implementation
   will never need to verify certificates from an authority which uses
   an ECDSA-384 signing key.

   Security-aware nodes in a Suite B compliant BSP implementation
   configured at a minimum level of security of 192 bits MUST use ECDSA-
   384 for authentication and MUST be able to verify ECDSA-384
   signatures.

4.3.  Digital Signatures and Certificates

   Security-aware nodes in a Suite B compliant BSP implementation, at
   both minimum levels of security, MUST each use an X.509 certificate
   that complies with the "Suite B Certificate and Certificate
   Revocation List (CRL) Profile" [RFC5759] and that contains an
   elliptic curve public key with the key usage field set for digital
   signature.  The endpoint IDs MUST be placed in the subjectAltName
   field of the X.509 certificate.


5.  Suite B Ciphersuites

   Each system MUST specify a security level of a minimum of 128 bits or
   192 bits.  The security level determines which suites from [SuiteB-
   suites] are allowed.

   Each of the eight ciphersuites specified in [SuiteB-suites]: BAB-
   HMAC256, BAB-HMAC384, PIB-ECDSA-SHA256, PIB-ECDSA-SHA384, PCB-ECDH-
   SHA256-AES128, PCB-ECDH-SHA384-AES256, ESB-ECDH-SHA256-AES128, and
   ESB-ECDH-SHA384-AES256, satisfy the Suite B requirements in Section 3
   of this document.

   At the 128-bit minimum level of security:




Burgin & Hennessy       Expires September 6, 2012               [Page 5]

Internet-Draft           Suite B Profile for BSP              March 2012


   o  If a Bundle Authentication Block (BAB) is included in the bundle,
      one of BAB-HMAC256 or BAB-HMAC384 MUST be used by Suite B
      compliant BSP implementations.

   o  If a Payload Integrity Block (PIB) is included in the bundle, one
      of PIB-ECDSA-SHA256 or PIB-ECDSA-SHA384 MUST be used by Suite B
      compliant BSP implementations.

   o  If a Payload Confidentiality Block (PCB) is included in the
      bundle, one of PCB-ECDH-SHA256-AES128 or PCB-ECDH-SHA384-AES256
      MUST be used by Suite B compliant BSP implementations.

   o  If a Extension Security Block (ESB) is included in the bundle, one
      of ESB-ECDH-SHA256-AES128 or and ESB-ECDH-SHA384-AES256 MUST be
      used by Suite B compliant BSP implementations.

   At the 192-bit minimum level of security:

   o  If a Bundle Authentication Block (BAB) is included in the bundle,
      BAB-HMAC384 MUST be used by Suite B compliant BSP implementations.

   o  If a Payload Integrity Block (PIB) is included in the bundle, PIB-
      ECDSA-SHA384 MUST be used by Suite B compliant BSP
      implementations.

   o  If a Payload Confidentiality Block (PCB) is included in the
      bundle, PCB-ECDH-SHA384-AES256 MUST be used by Suite B compliant
      BSP implementations.

   o  If a Extension Security Block (ESB) is included in the bundle,
      ESB-ECDH-SHA384-AES256 MUST be used by Suite B compliant BSP
      implementations.


6.  Security Considerations

   Two levels of security may be achieved using this specification.
   Users must consider their risk environment to determine which level
   is appropriate for their own use.

   The default security policy in Section 6 of [RFC6257] holds for Suite
   B compliant BSP implementations with the exception that the
   ciphersuites of [SuiteB-suites] MUST be used instead of the mandatory
   ciphersuites of [RFC6257].  The security considerations in [RFC6257]
   discuss the Bundle Security Protocol and apply here as well.

   RFC 6257 [RFC6257] Section 2.5 requires a different key be used for
   protecting ESBs than is used to protect other security blocks.  To



Burgin & Hennessy       Expires September 6, 2012               [Page 6]

Internet-Draft           Suite B Profile for BSP              March 2012


   satisfy this requirement, Suite B compliant BSP implementations
   SHOULD perform a new ECDH key exchange when protecting ESBs.  This is
   accomplished by the security source generating a new ephemeral key
   pair.

   Details for using CMS in Suite B can be found in [RFC6318].  The
   security considerations in [RFC5652] discuss the CMS as a method for
   digitally signing data and encrypting data.


7.  IANA Considerations

   none.


8.  References

8.1.  Normative References

   [FIPS180-3]
              National Institute of Standards and Technology, "Secure
              Hash Standard", FIPS PUB 180-3, October 2008.

   [FIPS186-3]
              National Institute of Standards and Technology, "Digital
              Signature Standard (DSS)", FIPS PUB 186-3, June 2009.

   [FIPS197]  National Institute of Standards and Technology, "Advanced
              Encryption Standard (AES)"", FIPS PUB 197, November 2001.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC5652]  Housley, R., "Cryptographic Message Syntax (CMS)", STD 70,
              RFC 5652, September 2009.

   [RFC5759]  Solinas, J. and L. Zieglar, "Suite B Certificate and
              Certificate Revocation List (CRL) Profile", RFC 5759,
              January 2010.

   [RFC6257]  Symington, S., Farrell, S., Weiss, H., and P. Lovell,
              "Bundle Security Protocol Specification", RFC 6257,
              May 2011.

   [RFC6318]  Housley, R. and J. Solinas, "Suite B in Secure/
              Multipurpose Internet Mail Extensions (S/MIME)", RFC 6318,
              June 2011.




Burgin & Hennessy       Expires September 6, 2012               [Page 7]

Internet-Draft           Suite B Profile for BSP              March 2012


   [SuiteB-suites]
              Burgin, K. and A. Hennessy, "Suite B Ciphersuites for the
              Bundle Security Protocol",
              draft-hennessy-bsp-suiteb-ciphersuites (work in progress),
              January 2012.

8.2.  Informative References

   [SP800-56A]
              National Institute of Standards and Technology,
              "Recommendation for Pair-wise Key Establishment Schemes
              Using Discrete Logarithm Cryptography", NIST Special
              Publication 800-56A, March 2007.

   [SuiteB]   U.S. National Security Agency, "Fact Sheet NSA Suite B
              Cryptography", January 2009,
              <http://www.nsa.gov/ia/programs/suiteb_cryptography/>.


Authors' Addresses

   Kelley Burgin
   National Security Agency


   Email: kwburgi@tycho.ncsc.mil


   Angela Hennessy
   National Security Agency


   Email: amhenne@nsa.gov


















Burgin & Hennessy       Expires September 6, 2012               [Page 8]


Html markup produced by rfcmarkup 1.109, available from https://tools.ietf.org/tools/rfcmarkup/