INTERNET-DRAFT L. Law Obsoletes: 4869 (if approved) J. Solinas Intended status: Informational NSA Expires: May 5, 2010 November 5, 2009 Suite B Cryptographic Suites for IPsec <draft-law-rfc4869bis-00.txt> Status of This Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet 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 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Law, Solinas Expires May 5, 2010 [Page 1]
RFC 4869 Suite B Cryptographic Suites for IPsec July 2009 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. This document obsoletes RFC 4869, which presented earlier versions of these suites. Table of Contents 1. Introduction ....................................................2 2. Requirements Terminology ........................................2 3. New UI Suites ...................................................3 3.1. Suite "Suite-B-GCM-128" ....................................3 3.2. Suite "Suite-B-GCM-256" ....................................4 3.3. Suite "Suite-B-GMAC-128" ...................................5 3.4. Suite "Suite-B-GMAC-256" ...................................6 3.5. Lifetimes for IKEv1 ........................................7 4. Security Considerations .........................................7 5. IANA Considerations .............................................7 6. Changes from RFC 4869............................................8 7. References ......................................................8 7.1. Normative References .......................................8 7.2. Informative References .....................................9 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 makes several minor changes to 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", "SHOULD", "SHOULD NOT", and "MAY" in this document are to be interpreted as described in [RFC2119]. Law, Solinas Expires May 5, 2010 [Page 2]
RFC 4869 Suite B Cryptographic Suites for IPsec October 2009 3. 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. 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 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] For IKEv1, Phase 1 MUST use Main mode. IKEv1 implementations MUST support pre-shared key authentication [RFC2409] for interoperability. The authentication method used with IKEv1 MUST 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] Law, Solinas Expires May 5, 2010 [Page 3]
RFC 4869 Suite B Cryptographic Suites for IPsec October 2009 The authentication method for systems that use IKEv2 MUST be either ECDSA-256 or ECDSA-384 [RFC4754]. It is allowable for one party to authenticate with ECDSA-256 and the other party to authenticate with ECDSA-384. However, the security level of each authentication method should be at least as high as the security strength desired for the negotiated security associations (SAs). To support interoperability when each party uses a different authentication method, all implementations SHOULD have the capability to verify both ECDSA-256 and ECDSA-384. Rekeying of Phase 2 (for IKEv1) or the CREATE_CHILD_SA (for IKEv2) MUST be supported by both parties in this suite. The initiator of this exchange MAY include a new Diffie-Hellman key; if it is included, it MUST use the 256-bit random ECP group. If the initiator of the exchange includes a Diffie-Hellman key, the responder MUST include a Diffie-Hellman key, and it MUST use the 256-bit random ECP group. 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 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] For IKEv1, Phase 1 MUST use Main mode. IKEv1 implementations MUST support pre-shared key authentication [RFC2409] for interoperability. The authentication method used with IKEv1 MUST 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] Law, Solinas Expires May 5, 2010 [Page 4]
RFC 4869 Suite B Cryptographic Suites for IPsec October 2009 The authentication method for systems that use IKEv2 MUST be either ECDSA-256 or ECDSA-384 [RFC4754]. It is allowable for one party to authenticate with ECDSA-256 and the other party to authenticate with ECDSA-384. However, the security level of each authentication method should be at least as high as the security strength desired for the negotiated security associations (SAs). To support interoperability when each party uses a different authentication method, all implementations SHOULD have the capability to verify both ECDSA-256 and ECDSA-384. Rekeying of Phase 2 (for IKEv1) or the CREATE_CHILD_SA (for IKEv2) MUST be supported by both parties in this suite. The initiator of this exchange MAY include a new Diffie-Hellman key; if it is included, it MUST use the 384-bit random ECP group. If the initiator of the exchange includes a Diffie-Hellman key, the responder MUST include a Diffie-Hellman key, and it MUST use the 384- bit random ECP group. 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 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] For IKEv1, Phase 1 MUST use Main mode. IKEv1 implementations MUST support pre-shared key authentication [RFC2409] for interoperability. The authentication method used with IKEv1 MUST 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] Law, Solinas Expires May 5, 2010 [Page 5]
RFC 4869 Suite B Cryptographic Suites for IPsec October 2009 The authentication method for systems that use IKEv2 MUST be either ECDSA-256 or ECDSA-384 [RFC4754]. It is allowable for one party to authenticate with ECDSA-256 and the other party to authenticate with ECDSA-384. However, the security level of each authentication method should be at least as high as the security strength desired for the negotiated security associations (SAs). To support interoperability when each party uses a different authentication method, all implementations SHOULD have the capability to verify both ECDSA-256 and ECDSA-384. Rekeying of Phase 2 (for IKEv1) or the CREATE_CHILD_SA (for IKEv2) MUST be supported by both parties in this suite. The initiator of this exchange MAY include a new Diffie-Hellman key; if it is included, it MUST use the 256-bit random ECP group. If the initiator of the exchange includes a Diffie-Hellman key, the responder MUST include a Diffie-Hellman key, and it MUST use the 256-bit random ECP group. 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] 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] For IKEv1, Phase 1 MUST use Main mode. IKEv1 implementations MUST support pre-shared key authentication [RFC2409] for interoperability. The authentication method used with IKEv1 MUST 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] Law, Solinas Expires May 5, 2010 [Page 6]
RFC 4869 Suite B Cryptographic Suites for IPsec October 2009 The authentication method for systems that use IKEv2 MUST be either ECDSA-256 or ECDSA-384 [RFC4754]. It is allowable for one party to authenticate with ECDSA-256 and the other party to authenticate with ECDSA-384. However, the security level of each authentication method should be at least as high as the security strength desired for the negotiated security associations (SAs). To support interoperability when each party uses a different authentication method, all implementations SHOULD have the capability to verify both ECDSA-256 and ECDSA-384. Rekeying of Phase 2 (for IKEv1) or the CREATE_CHILD_SA (for IKEv2) MUST be supported by both parties in this suite. The initiator of this exchange MAY include a new Diffie-Hellman key; if it is included, it MUST use the 384-bit random ECP group. If the initiator of the exchange includes a Diffie-Hellman key, the responder MUST include a Diffie-Hellman key, and it MUST use the 384- bit random ECP group. 3.5. Lifetimes for IKEv1 IKEv1 has two security parameters that do not appear in IKEv2, namely, the lifetime of the Phase 1 and Phase 2 security associations (SAs). Systems that use IKEv1 with any of the four suites given in this document MUST use an SA lifetime of 86400 seconds (1 day) for Phase 1 and an SA lifetime of 28800 seconds (8 hours) for Phase 2. 4. 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. 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 [RFC4869] as the RFC reference. These entries will be updated upon approval of this document. The updated values for the registry are: Law, Solinas Expires May 5, 2010 [Page 7]
RFC 4869 Suite B Cryptographic Suites for IPsec October 2009 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. In the IKEv2 case, removed the requirement for a single authentication method in each suite. Either party may now use either ECDSA-256 or ECDSA-384. This change will take advantage of IKEv2's capability to allow interoperability between an initiator and a responder that have different types of ECDSA authentication keys. 2. In the IKEv1 case, specified the SA lifetimes for both Phase 1 and Phase 2. 3. Clarified requirements for an optional Diffie-Hellman exchange in Phase 2 (for IKEv1) and the CREATE_CHILD_SA (for IKEv2). 4. Specified that the authentication method used with IKEv1 MUST be either pre-shared key or ECDSA. (MUST was previously MAY.) 5. In the IKEv1 case, specified that Phase 1 MUST use Main mode. (MUST was previously SHOULD.) 6. Deleted the statement that the IKEv1 group type is ECP in all four suites, since this is covered in the description of the Diffie-Hellman group. 7. References 7.1. Normative References [FIPS-180-3] FIPS 180-3, "Secure Hash Standard", National Institute of Standards and Technology, October 2008. [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. Law, Solinas Expires May 5, 2010 [Page 8]
RFC 4869 Suite B Cryptographic Suites for IPsec October 2009 [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. [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>. [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>. Law, Solinas Expires May 5, 2010 [Page 9]
RFC 4869 Suite B Cryptographic Suites for IPsec October 2007 [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, "NSA Suite B Cryptography", January 2009, <http://www.nsa.gov/ia/ programs/suiteb_cryptography/index.shtml>. 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 Law, Solinas Expires May 5, 2010 [Page 10]
