Suite B Cryptographic Suites for IPsec
draft-law-rfc4869bis-01

Internet-Draft                                                    L. Law
Obsoletes: 4869 (if approved)                                 J. Solinas
Intended status: Informational                                       NSA
Expires: August 14, 2011                               February 10, 2011

                Suite B Cryptographic Suites for IPsec
                    <draft-law-rfc4869bis-01.txt>

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Abstract

  This document proposes four cryptographic user interface suites 
  ("UI suites") for IPsec, similar to the two suites specified in
  RFC 4308.  The four new suites provide compatibility with the United
  States National Security Agency's Suite B specifications.  This
  document obsoletes RFC 4869, which presented earlier versions of these
  suites.

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Table of Contents

  1. Introduction ....................................................2
  2. Requirements Terminology ........................................2
  3. New UI Suites ...................................................2
     3.1. Suite "Suite-B-GCM-128" ....................................3
     3.2. Suite "Suite-B-GCM-256" ....................................3
     3.3. Suite "Suite-B-GMAC-128" ...................................3
     3.4. Suite "Suite-B-GMAC-256" ...................................4
  4. Security Considerations .........................................4
  5. IANA Considerations .............................................4
  6. Changes from RFC 4869............................................5
  7. References ......................................................5
     7.1. Normative References .......................................5
     7.2. Informative References .....................................6

1.  Introduction

  [RFC4308] proposes two optional cryptographic user interface suites
  ("UI suites") for IPsec.  The two suites, VPN-A and VPN-B, represent
  commonly used present-day corporate VPN security choices and
  anticipated future choices, respectively.  [RFC4869] proposed four new
  UI suites based on implementations of the United States National
  Security Agency's Suite B algorithms (see [SuiteB]). 

  As with the VPN suites, the Suite B suites are simply collections of
  values for some options in IPsec.  Use of UI suites does not change
  the IPsec protocols in any way.

  This document reduces the scope of the suites in [RFC4869] while
  retaining the original suite names. A detailed list of the changes is
  given in Section 6.  This document obsoletes RFC 4869.

2.  Requirements Terminology

  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.  New UI Suites

  Each of the following UI suites provides choices for ESP (see 
  [RFC4303]) and for IKEv2 (see [RFC5996]).  The four suites are
  differentiated by the choice of cryptographic algorithm strengths and
  a choice of whether the Encapsulating Security Payload (ESP) is to
  provide both confidentiality and integrity or integrity only.  The
  suite names are based on the Advanced Encryption Standard [AES] mode
  and AES key length specified for ESP.

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  IPsec implementations that use these UI suites MUST use the suite
  names listed here.  IPsec implementations SHOULD NOT use names
  different than those listed here for the suites that are described,
  and MUST NOT use the names listed here for suites that do not match
  these values.  These requirements are necessary for interoperability.

3.1.  Suite "Suite-B-GCM-128"

  This suite provides ESP integrity protection and confidentiality using
  128-bit AES-GCM (see [RFC4106]).  This suite or the following suite
  should be used when ESP integrity protection and encryption are both
  needed.

  ESP:
    Encryption     AES with 128-bit keys and 16-octet Integrity
                     Check Value (ICV) in GCM mode [RFC4106]
    Integrity      NULL

  IKEv2:
    Encryption                   AES with 128-bit keys in CBC mode
                                   [RFC3602]
    Pseudo-random function       HMAC-SHA-256 [RFC4868]
    Integrity                    HMAC-SHA-256-128 [RFC4868]
    Diffie-Hellman group         256-bit random ECP group [RFC5903]

3.2.  Suite "Suite-B-GCM-256"

  This suite provides ESP integrity protection and confidentiality using
  256-bit AES-GCM (see [RFC4106]).  This suite or the preceding suite
  should be used when ESP integrity protection and encryption are both
  needed.

  ESP:
    Encryption     AES with 256-bit keys and 16-octet ICV in GCM mode
                     [RFC4106]
    Integrity      NULL

  IKEv2:
    Encryption                   AES with 256-bit keys in CBC mode
                                   [RFC3602]
    Pseudo-random function       HMAC-SHA-384 [RFC4868]
    Integrity                    HMAC-SHA-384-192 [RFC4868]
    Diffie-Hellman group         384-bit random ECP group [RFC5903]

3.3.  Suite "Suite-B-GMAC-128"

  This suite provides ESP integrity protection using 128-bit AES-GMAC
  (see [RFC4543]) but does not provide confidentiality.  This suite or

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  the following suite should be used only when there is no need for ESP
  encryption.

  ESP:
    Encryption     NULL
    Integrity      AES with 128-bit keys in GMAC mode [RFC4543]

  IKEv2:
    Encryption                   AES with 128-bit keys in CBC mode
                                   [RFC3602]
    Pseudo-random function       HMAC-SHA-256 [RFC4868]
    Integrity                    HMAC-SHA-256-128 [RFC4868]
    Diffie-Hellman group         256-bit random ECP group [RFC5903]

3.4.  Suite "Suite-B-GMAC-256"

  This suite provides ESP integrity protection using 256-bit AES-GMAC
  (see [RFC4543]) but does not provide confidentiality.  This suite or
  the preceding suite should be used only when there is no need for ESP
  encryption.

  ESP:
    Encryption     NULL
    Integrity      AES with 256-bit keys in GMAC mode [RFC4543]

  IKEv2:
    Encryption                   AES with 256-bit keys in CBC mode
                                   [RFC3602]
    Pseudo-random function       HMAC-SHA-384 [RFC4868]
    Integrity                    HMAC-SHA-384-192 [RFC4868]
    Diffie-Hellman group         384-bit random ECP group [RFC5903]

4.  Security Considerations

  This document inherits all of the security considerations of the IPsec
  and IKEv2 documents.  

  Some of the security options specified in these suites may be found in
  the future to have properties significantly weaker than those that
  were believed at the time this document was produced.

5.  IANA Considerations

  IANA maintains a registry called "Cryptographic Suites for IKEv1,
  IKEv2, and IPsec" (see [IANA-Suites]).  The registry consists of a 
  text string and an RFC number that lists the associated transforms.
  The four suites in this document have been listed with this document 
  as the RFC reference.  These entries will be updated upon approval of 
  this document.

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  The updated values for the registry are:

  Identifier              Defined in
  Suite-B-GCM-128         this document
  Suite-B-GCM-256         this document
  Suite-B-GMAC-128        this document
  Suite-B-GMAC-256        this document

6.  Changes from RFC 4869

  The changes from [RFC4869] are:

  1.  Removed definitions of the suites for IKEv1.

  2.  Removed IKE authentication methods from the suite definitions.
      These now appear in [SuiteB-IPsec-Profile].

  3.  Removed the requirements on rekeying in IKEv2.

7.  References

7.1.  Normative References

  [IANA-Suites] Internet Assigned Numbers Authority, "Cryptographic
                Suites for IKEv1, IKEv2, and IPsec",
                <http://www.iana.org/assignments/crypto-suites>.

  [RFC2119]     Bradner, S., "Key words for use in RFCs to Indicate
                Requirement Levels", BCP 14, RFC 2119, March 1997.
  
  [RFC3602]     Frankel, S., Glenn, R., and S. Kelly, "The AES-CBC
                Cipher Algorithm and Its Use with IPsec", RFC 3602,
                September 2003.

  [RFC4106]     Viega, J. and D. McGrew, "The Use of Galois/Counter
                Mode (GCM) in IPsec Encapsulating Security Payload
                (ESP)", RFC 4106, June 2005.

  [RFC4303]     Kent, S., "IP Encapsulating Security Payload (ESP)",
                RFC 4303, December 2005.

  [RFC5996]     Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen, 
                "Internet Key Exchange Protocol Version 2 (IKEv2)",
                RFC 5996,  September 2010.

  [RFC4308]     Hoffman, P., "Cryptographic Suites for IPsec", RFC
                4308, December 2005.

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  [RFC4543]     McGrew, D. and J. Viega, "The Use of Galois Message
                Authentication Code (GMAC) in IPsec ESP and AH", RFC
                4543, May 2006.

  [RFC5903]     Fu, D., and J. Solinas,"Elliptic Curve Groups modulo a 
                Prime (ECP Groups) for IKE and IKEv2", RFC 5903, June
                2010.

  [RFC4868]     Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-
                SHA-384, and HMAC-SHA-512 with IPsec", RFC 4868, May
                2007.

  [RFC4869]     Law, L. and J. Solinas, "Suite B Cryptographic Suites 
                for IPsec", RFC 4869, May 2007.

7.2.  Informative References

  [AES]         U.S. Department of Commerce/National Institute of
                Standards and Technology, "Advanced Encryption Standard
                (AES)", FIPS PUB 197, November 2001,
                <http://csrc.nist.gov/publications/fips/index.html>.

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

  [SuiteB-IPsec-Profile]
                Burgin, K. and M. Peck, "Suite B Profile for Internet
                Protocol Security (IPsec)", (work in progress),
                draft-burgin-ipsec-suiteb-profile-00, February 2011. 

Authors' Addresses

  Laurie E. Law
  National Information Assurance Research Laboratory
  National Security Agency

  EMail: lelaw@orion.ncsc.mil

  Jerome A. Solinas
  National Information Assurance Research Laboratory
  National Security Agency

  EMail: jasolin@orion.ncsc.mil

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