RFC4869
Network Working Group L. Law Request for Comments: 4869 J. Solinas Category: Informational NSA
May 2007
Suite B Cryptographic Suites for IPsec
Status of This Memo
This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This document proposes four optional 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.
Contents
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. This document proposes 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.
Requirements Terminology
The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY" in this document are to be interpreted as described in RFC2119.
New UI Suites
Each of the following UI suites provides choices for ESP (see RFC4303) and for IKEv1 and IKEv2 (see RFC2409 and RFC4306). 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.
IPsec implementations that use these UI suites SHOULD 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.
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
IKEv1:
Encryption AES with 128-bit keys in CBC mode
RFC3602
Pseudo-random function HMAC-SHA-256 RFC4868
Hash SHA-256 [FIPS-180-2] RFC4634
Diffie-Hellman group 256-bit random ECP group RFC4753
Group Type ECP
For IKEv1, Phase 1 SHOULD use Main mode. IKEv1 implementations MUST support pre-shared key authentication RFC2409 for interoperability. The authentication method used with IKEv1 MAY be either pre-shared key RFC2409 or ECDSA-256 RFC4754.
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 RFC4753
Authentication ECDSA-256 RFC4754
Rekeying of Phase 2 (for IKEv1) or the CREATE_CHILD_SA (for IKEv2) MUST be supported by both parties in this suite.
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
IKEv1:
Encryption AES with 256-bit keys in CBC mode
RFC3602
Pseudo-random function HMAC-SHA-384 RFC4868
Hash SHA-384 [FIPS-180-2] RFC4634
Diffie-Hellman group 384-bit random ECP group RFC4753
Group Type ECP
For IKEv1, Phase 1 SHOULD use Main mode. IKEv1 implementations MUST support pre-shared key authentication RFC2409 for interoperability. The authentication method used with IKEv1 MAY be either pre-shared key RFC2409 or ECDSA-384 RFC4754.
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 RFC4753
Authentication ECDSA-384 RFC4754
Rekeying of Phase 2 (for IKEv1) or the CREATE_CHILD_SA (for IKEv2) MUST be supported by both parties in this suite.
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 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
IKEv1:
Encryption AES with 128-bit keys in CBC mode
RFC3602
Pseudo-random function HMAC-SHA-256 RFC4868
Hash SHA-256 [FIPS-180-2] RFC4634
Diffie-Hellman group 256-bit random ECP group RFC4753
Group Type ECP
For IKEv1, Phase 1 SHOULD use Main mode. IKEv1 implementations MUST support pre-shared key authentication RFC2409 for interoperability. The authentication method used with IKEv1 MAY be either pre-shared key RFC2409 or ECDSA-256 RFC4754.
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 RFC4753
Authentication ECDSA-256 RFC4754
Rekeying of Phase 2 (for IKEv1) or the CREATE_CHILD_SA (for IKEv2) MUST be supported by both parties in this suite.
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
IKEv1:
Encryption AES with 256-bit keys in CBC mode
RFC3602
Pseudo-random function HMAC-SHA-384 RFC4868
Hash SHA-384 [FIPS-180-2] RFC4634
Diffie-Hellman group 384-bit random ECP group RFC4753
Group Type ECP
For IKEv1, Phase 1 SHOULD use Main mode. IKEv1 implementations MUST support pre-shared key authentication RFC2409 for interoperability. The authentication method used with IKEv1 MAY be either pre-shared key RFC2409 or ECDSA-384 RFC4754.
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 RFC4753
Authentication ECDSA-384 RFC4754
Rekeying of Phase 2 (for IKEv1) or the CREATE_CHILD_SA (for IKEv2) MUST be supported by both parties in this suite.
Security Considerations
This document inherits all of the security considerations of the IPsec, IKEv1, and IKEv2 documents. See [CNSSP-15] for guidance on the use of AES in these suites for the protection of U.S. Government information.
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.
IANA Considerations
IANA has created and will maintain 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 new suites in this document have been added to this registry after approval by an expert designated by the IESG.
The new values for the registry are:
Identifier Defined in Suite-B-GCM-128 RFC 4869 Suite-B-GCM-256 RFC 4869 Suite-B-GMAC-128 RFC 4869 Suite-B-GMAC-256 RFC 4869
References
Normative References
[FIPS-180-2] FIPS 180-2 with change notice, "Secure Hash Standard",
National Institute of Standards and Technology,
February 2004.
[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.
RFC2409 Harkins, D. and D. Carrel, "The Internet Key Exchange
(IKE)", RFC 2409, November 1998.
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.
RFC4306 Kaufman, C., "Internet Key Exchange (IKEv2) Protocol",
RFC 4306, December 2005.
RFC4308 Hoffman, P., "Cryptographic Suites for IPsec", RFC
4308, December 2005.
RFC4543 McGrew, D. and J. Viega, "The Use of Galois Message
Authentication Code (GMAC) in IPsec ESP and AH", RFC
4543, May 2006.
RFC4753 Fu, D. and J. Solinas, "ECP Groups for IKE and IKEv2",
RFC 4753, November 2006.
RFC4754 Fu, D. and J. Solinas, "IKE and IKEv2 Authentication
Using ECDSA", RFC 4754, November 2006.
RFC4868 Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-
SHA-384, and HMAC-SHA-512 with IPsec", RFC 4868, May 2007.
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>.
[CNSSP-15] Committee on National Security Systems, "National
Policy on the Use of the Advanced Encryption Standard
(AES) to Protect National Security Systems and National
Security Information", June 2003,
<http://www.cnss.gov/Assets/pdf/cnssp_15_fs.pdf>.
RFC4634 Eastlake 3rd, D. and T. Hansen, "US Secure Hash
Algorithms (SHA and HMAC-SHA)", RFC 4634, July 2006.
[SuiteB] U.S. National Security Agency, "Fact Sheet NSA Suite B
Cryptography", July 2005, <http://www.nsa.gov/ia/ industry/crypto_Suite_b.cfm?MenuID=10.2.7>.
Authors' Addresses
Laurie E. Law National Information Assurance Research Laboratory National Security Agency
EMail: [email protected]
Jerome A. Solinas National Information Assurance Research Laboratory National Security Agency
EMail: [email protected]
Full Copyright Statement
Copyright (C) The IETF Trust (2007).
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