Network Working Group                                         P. Hoffman
Request for Comments: 3664                                VPN Consortium
Category: Standards Track                                   January 2004
        
Network Working Group                                         P. Hoffman
Request for Comments: 3664                                VPN Consortium
Category: Standards Track                                   January 2004

The AES-XCBC-PRF-128 Algorithm for the Internet Key Exchange Protocol (IKE)

因特网密钥交换协议（IKE）的AES-XCBC-PRF-128算法

Status of this Memo

本备忘录的状况

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.

本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。

Copyright Notice

版权公告

Copyright (C) The Internet Society (2004). All Rights Reserved.

版权所有（C）互联网协会（2004年）。版权所有。

Abstract

摘要

Some implementations of IP Security (IPsec) may want to use a pseudo-random function derived from the Advanced Encryption Standard (AES). This document describes such an algorithm, called AES-XCBC-PRF-128.

IP安全（IPsec）的某些实现可能希望使用从高级加密标准（AES）派生的伪随机函数。本文件描述了一种称为AES-XCBC-PRF-128的算法。

1. Introduction
1. 介绍

[AES-XCBC-MAC] describes a method to use the Advanced Encryption Standard (AES) as a message authentication code (MAC) whose output is 96 bits long. While 96 bits is considered appropriate for a MAC, it is too short to be useful as a long-lived pseudo-random (PRF) in either IKE version 1 or version 2. Both versions of IKE use the PRF to create keys in a fashion that is dependent on the length of the output of the PRF. Using a PRF that has 96 bits of output creates keys that are easier to attack with brute force than a PRF that uses 128 bits of output.

[AES-XCBC-MAC]描述了一种将高级加密标准（AES）用作消息认证码（MAC）的方法，该码的输出长度为96位。虽然96位被认为适合MAC，但它太短，在IKE版本1或版本2中都不能用作长寿命伪随机（PRF）。IKE的两个版本都使用PRF以一种依赖于PRF输出长度的方式创建关键帧。使用96位输出的PRF创建的密钥比使用128位输出的PRF更容易受到暴力攻击。

Fortunately, there is a very simple method to use much of [AES-XCBC-MAC] as a PRF whose output is 128 bits: omit the step that truncates the 128-bit value to 96 bits.

幸运的是，有一种非常简单的方法可以将[AES-XCBC-MAC]的大部分用作输出为128位的PRF：省略将128位值截断为96位的步骤。

2. The AES-XCBC-PRF-128 Algorithm
2. AES-XCBC-PRF-128算法

The AES-XCBC-PRF-128 algorithm is identical to [AES-XCBC-MAC] except that the truncation step in section 4.3 of [AES-XCBC-MAC] is *not* performed. That is, there is no processing after section 4.2 of [AES-XCBC-MAC].

AES-XCBC-PRF-128算法与[AES-XCBC-MAC]相同，只是没有执行[AES-XCBC-MAC]第4.3节中的截断步骤。也就是说，在[AES-XCBC-MAC]第4.2节之后没有处理。

The test vectors in section 4.6 can be used for AES-XCBC-PRF-128, but only those listed as "AES-XCBC-MAC", not "AES-XCBC-MAC-96".

第4.6节中的测试向量可用于AES-XCBC-PRF-128，但仅限于列为“AES-XCBC-MAC”而非“AES-XCBC-MAC-96”的测试向量。

3. Security Considerations
3. 安全考虑

The security provided by AES-XCBC-MAC-PRF is based upon the strength of AES. At the time of this writing, there are no known practical cryptographic attacks against AES or AES-XCBC-MAC-PRF.

AES-XCBC-MAC-PRF提供的安全性基于AES的强度。在撰写本文时，还没有已知的针对AES或AES-XCBC-MAC-PRF的实用加密攻击。

As is true with any cryptographic algorithm, part of its strength lies in the security of the key management mechanism, the strength of the associated secret key, and upon the correctness of the implementations in all of the participating systems. [AES-XCBC-MAC] contains test vectors to assist in verifying the correctness of the AES-XCBC-MAC-PRF code. The test vectors all show the full MAC value before it is truncated to 96 bits. The PRF makes use of the full MAC value, not the truncated one.

与任何加密算法一样，其部分优势在于密钥管理机制的安全性、相关密钥的强度以及所有参与系统中实现的正确性。[AES-XCBC-MAC]包含测试向量，以帮助验证AES-XCBC-MAC-PRF代码的正确性。测试向量在被截断为96位之前都显示完整的MAC值。PRF使用完整的MAC值，而不是截断的MAC值。

4. Intellectual Property Statement
4. 知识产权声明

The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication 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 implementors or users of this specification can be obtained from the IETF Secretariat.

IETF对可能声称与本文件所述技术的实施或使用有关的任何知识产权或其他权利的有效性或范围，或此类权利下的任何许可可能或可能不可用的程度，不采取任何立场；它也不表示它已作出任何努力来确定任何此类权利。有关IETF在标准跟踪和标准相关文件中权利的程序信息，请参见BCP-11。可从IETF秘书处获得可供发布的权利声明副本和任何许可证保证，或本规范实施者或用户试图获得使用此类专有权利的一般许可证或许可的结果。

The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director.

IETF邀请任何相关方提请其注意任何版权、专利或专利申请，或其他可能涉及实施本标准所需技术的专有权利。请将信息发送给IETF执行董事。

5. References
5. 工具书类
5.1. Normative References
5.1. 规范性引用文件

[AES-XCBC-MAC] Frankel, S. and H. Herbert, "The AES-XCBC-MAC-96 Algorithm and Its Use With IPsec", RFC 3566, September 2003.

[AES-XCBC-MAC]Frankel，S.和H.Herbert，“AES-XCBC-MAC-96算法及其与IPsec的使用”，RFC 3566，2003年9月。

6. Author's Address
6. 作者地址

Paul Hoffman VPN Consortium 127 Segre Place Santa Cruz, CA 95060 USA

美国加利福尼亚州圣克鲁斯塞格雷广场127号保罗·霍夫曼VPN联盟，邮编95060 

   EMail: paul.hoffman@vpnc.org
        
   EMail: paul.hoffman@vpnc.org
7. Full Copyright Statement
7. 完整版权声明

Copyright (C) The Internet Society (2004). All Rights Reserved.

版权所有（C）互联网协会（2004年）。版权所有。

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.

本文件及其译本可复制并提供给他人，对其进行评论或解释或协助其实施的衍生作品可全部或部分编制、复制、出版和分发，不受任何限制，前提是上述版权声明和本段包含在所有此类副本和衍生作品中。但是，不得以任何方式修改本文件本身，例如删除版权通知或对互联网协会或其他互联网组织的引用，除非出于制定互联网标准的需要，在这种情况下，必须遵循互联网标准过程中定义的版权程序，或根据需要将其翻译成英语以外的其他语言。

The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assignees.

上述授予的有限许可是永久性的，互联网协会或其继承人或受让人不会撤销。

This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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.

本文件和其中包含的信息是按“原样”提供的，互联网协会和互联网工程任务组否认所有明示或暗示的保证，包括但不限于任何保证，即使用本文中的信息不会侵犯任何权利，或对适销性或特定用途适用性的任何默示保证。

Acknowledgement

确认

Funding for the RFC Editor function is currently provided by the Internet Society.

RFC编辑功能的资金目前由互联网协会提供。