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Network Working Group S. Moriai Request for Comments: 4132 Sony Computer Entertainment Inc. Category: Standards Track A. Kato NTT Software Corporation M. Kanda Nippon Telegraph and Telephone Corporation July 2005 Addition of Camellia Cipher Suites to Transport Layer Security (TLS) Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document proposes the addition of new cipher suites to the Transport Layer Security (TLS) protocol to support the Camellia encryption algorithm as a bulk cipher algorithm. 1. Introduction This document proposes the addition of new cipher suites to the TLS protocol [TLS] to support the Camellia encryption algorithm as a bulk cipher algorithm. This proposal provides a new option for fast and efficient bulk cipher algorithms. Note: This work was done when the first author worked for NTT. 1.1. Camellia Camellia was selected as a recommended cryptographic primitive by the EU NESSIE (New European Schemes for Signatures, Integrity and Encryption) project [NESSIE] and included in the list of cryptographic techniques for Japanese e-Government systems, which were selected by the Japan CRYPTREC (Cryptography Research and Evaluation Committees) [CRYPTREC]. Camellia is also included in specification of the TV-Anytime Forum [TV-ANYTIME]. The TV-Anytime Forum is an association of organizations that seeks to develop Moriai, et al. Standards Track [Page 1]
RFC 4132 Camellia Cipher Suites for TLS July 2005 specifications to enable audio-visual and other services based on mass-market high-volume digital storage in consumer platforms. Camellia is specified as Cipher Suite in TLS used by Phase 1 S-7 (Bi-directional Metadata Delivery Protection) specification and S-5 (TV-Anytime Rights Management and Protection Information for Broadcast Applications) specification. Camellia has been submitted to other several standardization bodies such as ISO (ISO/IEC 18033) and IETF S/MIME Mail Security Working Group [Camellia-CMS]. Camellia supports 128-bit block size and 128-, 192-, and 256-bit key sizes; i.e., the same interface specifications as the Advanced Encryption Standard (AES) [AES]. Camellia was jointly developed by NTT and Mitsubishi Electric Corporation in 2000 [CamelliaTech]. It was carefully designed to withstand all known cryptanalytic attacks and even to have a sufficiently large security leeway. It has been scrutinized by worldwide cryptographic experts. Camellia was also designed to be suitable for both software and hardware implementations and to cover all possible encryption applications, from low-cost smart cards to high-speed network systems. Compared to the AES, Camellia offers at least comparable encryption speed in software and hardware. In addition, a distinguishing feature is its small hardware design. Camellia perfectly meets one of the current TLS market requirements, for which low power consumption is mandatory. The algorithm specification and object identifiers are described in [Camellia-Desc]. The Camellia homepage, http://info.isl.ntt.co.jp/camellia/, contains a wealth of information about camellia, including detailed specification, security analysis, performance figures, reference implementation, and test vectors. 1.2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document (in uppercase, as shown) are to be interpreted as described in [RFC2119]. 2. Proposed Cipher Suites The new cipher suites proposed here have the following definitions: CipherSuite TLS_RSA_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x41 }; CipherSuite TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x42 }; CipherSuite TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x43 }; CipherSuite TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x44 }; Moriai, et al. Standards Track [Page 2]
RFC 4132 Camellia Cipher Suites for TLS July 2005 CipherSuite TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x45 }; CipherSuite TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x46 }; CipherSuite TLS_RSA_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x84 }; CipherSuite TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x85 }; CipherSuite TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x86 }; CipherSuite TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x87 }; CipherSuite TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x88 }; CipherSuite TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x89 }; 3. Cipher Suite Definitions 3.1. Cipher All the cipher suites described here use Camellia in cipher block chaining (CBC) mode as a bulk cipher algorithm. Camellia is a 128- bit block cipher with 128-, 192-, and 256-bit key sizes; i.e., it supports the same block and key sizes as the Advanced Encryption Standard (AES). However, this document only defines cipher suites for 128- and 256-bit keys as well as AES cipher suites for TLS [AES-TLS]. These cipher suites are efficient and practical enough for most uses, including high-security applications. Key Expanded Effective IV Block Cipher Type Material Key Material Key Bits Size Size CAMELLIA_128_CBC Block 16 16 128 16 16 CAMELLIA_256_CBC Block 32 32 256 16 16 3.2. Hash All the cipher suites described here use SHA-1 [SHA-1] in a Hashed Message Authentication Code (HMAC) construction, as described in section 5 of [TLS]. 3.3. Key Exchange The cipher suites defined here differ in the type of certificate and key exchange method. They use the following options: Cipher Suite Key Exchange Algorithm TLS_RSA_WITH_CAMELLIA_128_CBC_SHA RSA TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA DH_DSS TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA DH_RSA TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA DHE_DSS TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA DHE_RSA TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA DH_anon Moriai, et al. Standards Track [Page 3]
RFC 4132 Camellia Cipher Suites for TLS July 2005 TLS_RSA_WITH_CAMELLIA_256_CBC_SHA RSA TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA DH_DSS TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA DH_RSA TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA DHE_DSS TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA DHE_RSA TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA DH_anon For the meanings of the terms RSA, DH_DSS, DH_RSA, DHE_DSS, DHE_RSA, and DH_anon, please refer to sections 7.4.2 and 7.4.3 of [TLS]. 4. Security Considerations It is not believed that the new cipher suites are ever less secure than the corresponding older ones. Camellia is considered secure, and it has withstood extensive cryptanalytic efforts in several open, worldwide cryptographic evaluation projects [CRYPTREC][NESSIE]. At the time of writing this document, there are no known weak keys for Camellia. For other security considerations, please refer to the security considerations of the corresponding older cipher suites described in [TLS] and [AES-TLS]. 5. References 5.1. Normative References [Camellia-Desc] Matsui, M., Nakajima, J., and S. Moriai, "A Description of the Camellia Encryption Algorithm", RFC 3713, April 2004. [TLS] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", RFC 2246, January 1999. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 5.2. Informative References [CamelliaTech] Aoki, K., Ichikawa, T., Kanda, M., Matsui, M., Moriai, S., Nakajima, J., and Tokita, T., "Camellia: A 128-Bit Block Cipher Suitable for Multiple Platforms - Design and Analysis -", In Selected Areas in Cryptography, 7th Annual International Workshop, SAC 2000, August 2000, Proceedings, Lecture Notes in Computer Science 2012, pp.39-56, Springer-Verlag, 2001. Moriai, et al. Standards Track [Page 4]
RFC 4132 Camellia Cipher Suites for TLS July 2005 [Camellia-CMS] Moriai, S. and A. Kato, "Use of the Camellia Encryption Algorithm in Cryptographic Message Syntax (CMS)", RFC 3657, January 2004. [AES] NIST, FIPS PUB 197, "Advanced Encryption Standard (AES)", November 2001. http://csrc.nist.gov/publications/fips/fips197/fips- 197.{ps,pdf}. [AES-TLS] Chown, P., "Advanced Encryption Standard (AES) Ciphersuites for Transport Layer Security (TLS)", RFC 3268, June 2002. [SHA-1] FIPS PUB 180-1, "Secure Hash Standard", National Institute of Standards and Technology, U.S. Department of Commerce, April 17, 1995. [CRYPTREC] Information-technology Promotion Agency (IPA), Japan, CRYPTREC, http://www.ipa.go.jp/security/enc/CRYPTREC/index- e.html. [NESSIE] The NESSIE project (New European Schemes for Signatures, Integrity and Encryption), http://www.cosic.esat.kuleuven.ac.be/nessie/. [TV-ANYTIME] TV-Anytime Forum, http://www.tv-anytime.org/. Moriai, et al. Standards Track [Page 5]
RFC 4132 Camellia Cipher Suites for TLS July 2005 Authors' Addresses Shiho Moriai Sony Computer Entertainment Inc. Phone: +81-3-6438-7523 Fax: +81-3-6438-8629 EMail: shiho@rd.scei.sony.co.jp Akihiro Kato NTT Software Corporation Phone: +81-45-212-7094 Fax: +81-45-212-7506 EMail: akato@po.ntts.co.jp Masayuki Kanda Nippon Telegraph and Telephone Corporation Phone: +81-46-859-2437 Fax: +81-46-859-3365 EMail: kanda.masayuki@lab.ntt.co.jp camellia@lab.ntt.co.jp (Camellia team) Moriai, et al. Standards Track [Page 6]
RFC 4132 Camellia Cipher Suites for TLS July 2005 Full Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf- ipr@ietf.org. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Moriai, et al. Standards Track [Page 7]