Independent Submission                                         S. Turner
Request for Comments: 7169                                    IECA, Inc.
Category: Informational                                     1 April 2014
ISSN: 2070-1721
Independent Submission                                         S. Turner
Request for Comments: 7169                                    IECA, Inc.
Category: Informational                                     1 April 2014
ISSN: 2070-1721

The NSA (No Secrecy Afforded) Certificate Extension




This document defines the NSA (No Secrecy Afforded) certificate extension appropriate for use in certain PKIX (X.509 Pubic Key Certificates) digital certificates. Historically, clients and servers strived to maintain the privacy of their keys; however, the secrecy of their private keys cannot always be maintained. In certain circumstances, a client or a server might feel that they will be compelled in the future to share their keys with a third party. Some clients and servers also have been compelled to share their keys and wish to indicate to relying parties upon certificate renewal that their keys have in fact been shared with a third party.


Status of This Memo


This document is not an Internet Standards Track specification; it is published for informational purposes.


This is a contribution to the RFC Series, independently of any other RFC stream. The RFC Editor has chosen to publish this document at its discretion and makes no statement about its value for implementation or deployment. Documents approved for publication by the RFC Editor are not a candidate for any level of Internet Standard; see Section 2 of RFC 5741.

这是对RFC系列的贡献,独立于任何其他RFC流。RFC编辑器已选择自行发布此文档,并且未声明其对实现或部署的价值。RFC编辑批准发布的文件不适用于任何级别的互联网标准;见RFC 5741第2节。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved.

版权所有(c)2014 IETF信托基金和确定为文件作者的人员。版权所有。

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. Please review these documents carefully, as they describe your rights and restrictions with respect to this document.

本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(自本文件出版之日起生效。请仔细阅读这些文件,因为它们描述了您对本文件的权利和限制。

1. Introduction
1. 介绍

Insecurity abounds when clients and servers are unable to keep their private keys private. Situations exist nonetheless where client and servers have shared their private keys with a third party. An example of over-sharing might be lawful intercept.


Just because the private key has been shared does not mean that the private key holder wants to conceal the fact they have shared their private key with a third party. Overtly indicating that the private key may be or has been shared with a third party is the best way to indicate to relying parties that this sharing has occurred. Knowledge is power, after all. Extensions for certificates [RFC5280] offer an excellent mechanism to indicate that the entities key(s) have been shared, and this document specifies one such certificate extension for use by entities that have shared their private key: the NSA (No Secrecy Afforded) certificate extension.


2. The NSA Certificate Extension
2. NSA证书扩展

In order to allow entities that have shared their keys with a third party, the NSA certificate extension is defined herein. ASN.1 [X.680] for the extension follows:


   ext-KeyUsage EXTENSION ::= { SYNTAX
         BOOLEAN  IDENTIFIED BY id-pe-nsa }
   ext-KeyUsage EXTENSION ::= { SYNTAX
         BOOLEAN  IDENTIFIED BY id-pe-nsa }
   id-pe-nsa OBJECT IDENTIFIER ::=  { id-pe 23 }
   id-pe-nsa OBJECT IDENTIFIER ::=  { id-pe 23 }

Making the boolean TRUE indicates that the key has been shared with a third party, and making the extension FALSE indicates that the key may have also been shared with a third party but the signer does not want to overtly indicate that the key has been shared. This extension is always marked critical.


3. Security Considerations
3. 安全考虑

Having to disclose keys is sometimes unavoidable. Explicitly indicating that the keys have been shared is one way to mitigate the risk that the relying party might be unaware of this over share. Whatever the case for having shared the keys, the certificate signer needs to careful consider whether to include this extension.


Any key with this extension must be trusted with care. Lengthy deliberations about whether to trust the keys is necessary. Rushing a security analysis is never a good thing. Ultimately, the keys need not be trusted. Secrecy is hard.


4. Normative References
4. 规范性引用文件

[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, May 2008.

[RFC5280]Cooper,D.,Santesson,S.,Farrell,S.,Boeyen,S.,Housley,R.,和W.Polk,“Internet X.509公钥基础设施证书和证书撤销列表(CRL)配置文件”,RFC 52802008年5月。

[X.680] ITU-T, "Information technology - Abstract Syntax Notation One (ASN.1): Specification of basic notation", ITU-T Recommendation X.680 (2002) | ISO/IEC 8824-1:2002, 2002.

[X.680]ITU-T,“信息技术-抽象语法符号1(ASN.1):基本符号规范”,ITU-T建议X.680(2002)| ISO/IEC 8824-1:2002。

Author's Address


Sean Turner IECA, Inc. 3057 Nutley Street, Suite 106 Fairfax, VA 22031 USA

Sean Turner IECA,Inc.美国弗吉尼亚州费尔法克斯市努特利街3057号106室,邮编22031