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>
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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].
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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]
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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]
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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]
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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]
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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:
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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
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.
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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>.
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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
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