Internet Engineering Task Force (IETF) P. Yee
Request for Comments: 6818 AKAYLA
Updates: 5280 January 2013
Category: Standards Track
ISSN: 2070-1721
Internet Engineering Task Force (IETF) P. Yee
Request for Comments: 6818 AKAYLA
Updates: 5280 January 2013
Category: Standards Track
ISSN: 2070-1721
Updates to the Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile
Internet X.509公钥基础结构证书和证书吊销列表（CRL）配置文件的更新
Abstract
摘要
This document updates RFC 5280, the "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile". This document changes the set of acceptable encoding methods for the explicitText field of the user notice policy qualifier and clarifies the rules for converting internationalized domain name labels to ASCII. This document also provides some clarifications on the use of self-signed certificates, trust anchors, and some updated security considerations.
本文档更新了RFC 5280，即“Internet X.509公钥基础设施证书和证书吊销列表（CRL）配置文件”。本文档更改了用户通知策略限定符的explicitText字段的可接受编码方法集，并澄清了将国际化域名标签转换为ASCII的规则。本文档还对自签名证书的使用、信任锚以及一些更新的安全注意事项进行了说明。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见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 http://www.rfc-editor.org/info/rfc6818.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc6818.
Copyright Notice
版权公告
Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2013 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 (http://trustee.ietf.org/license-info) 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. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)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。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction ....................................................2
1.1. Terminology ................................................3
2. Update to RFC 5280, Section 3.2: "Certification Paths and Trust" 3
3. Update to RFC 5280, Section 4.2.1.4: "Certificate Policies" .....3
4. Update to RFC 5280, Section 6.2: "Using the Path Validation
Algorithm" ......................................................4
5. Update to RFC 5280, Section 7.3: "Internationalized
Domain Names in Distinguished Names" ............................5
6. Security Considerations .........................................5
7. Update to RFC 5280, Section 11.1: "Normative References" ........7
8. Update to RFC 5280, Section 11.2: "Informative References" ......7
9. References ......................................................7
9.1. Normative References .......................................7
9.2. Informative References .....................................7
10. Acknowledgements ................................................8
1. Introduction ....................................................2
1.1. Terminology ................................................3
2. Update to RFC 5280, Section 3.2: "Certification Paths and Trust" 3
3. Update to RFC 5280, Section 4.2.1.4: "Certificate Policies" .....3
4. Update to RFC 5280, Section 6.2: "Using the Path Validation
Algorithm" ......................................................4
5. Update to RFC 5280, Section 7.3: "Internationalized
Domain Names in Distinguished Names" ............................5
6. Security Considerations .........................................5
7. Update to RFC 5280, Section 11.1: "Normative References" ........7
8. Update to RFC 5280, Section 11.2: "Informative References" ......7
9. References ......................................................7
9.1. Normative References .......................................7
9.2. Informative References .....................................7
10. Acknowledgements ................................................8
This document updates the "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile" [RFC5280].
本文档更新了“Internet X.509公钥基础设施证书和证书吊销列表（CRL）配置文件”[RFC5280]。
This document makes a recommendation that self-signed certificates used to convey trust anchor data be marked as certificate authority (CA) certificates, which is not always current practice.
本文档建议将用于传递信任锚数据的自签名证书标记为证书颁发机构（CA）证书，这并不总是当前的做法。
The use of self-signed certificates as trust anchors in Section 6.2 of [RFC5280] is clarified. While it is optional to use additional information in these certificates in the path validation process, [RFC5937] is noted as providing guidance in that regard.
[RFC5280]第6.2节澄清了自签名证书作为信任锚的使用。虽然在路径验证过程中使用这些证书中的附加信息是可选的，但[RFC5937]在这方面提供了指导。
The acceptable and unacceptable encodings for the explicitText field of the user notice policy qualifier are updated to bring them in line with existing practice.
将更新用户通知策略限定符的explicitText字段的可接受和不可接受编码，以使其与现有实践保持一致。
The rules in Section 7.3 of [RFC5280] for ASCII encoding of Internationalized Domain Names (IDNs) as Distinguished Names are aligned with the rules in Section 7.2 of that document that govern IDN encoding as GeneralNames.
[RFC5280]第7.3节中关于将国际域名（IDN）作为可分辨名称进行ASCII编码的规则与该文件第7.2节中关于将IDN编码作为一般名称的规则一致。
In light of some observed attacks [Prins], the Security Considerations section now gives added depth to the consequences of CA key compromise. This section additionally notes that collision resistance is not a required property of one-way hash functions when used to generate key identifiers.
根据观察到的一些攻击[Prins]，安全注意事项部分现在对CA密钥泄露的后果进行了更深入的分析。本节还注意到，当用于生成密钥标识符时，抗冲突不是单向散列函数的必需属性。
This document also adds normative and informative references for Trust Anchor formats and how they may be used to initialize the path validation inputs. These are needed as a result of the changes made in Section 4 of this document.
本文档还为信任锚格式以及如何使用它们初始化路径验证输入添加了规范性和信息性参考。由于本文件第4节中所做的更改，需要这些文件。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中所述进行解释。
Add the following paragraph to the end of RFC 5280, Section 3.2:
在RFC 5280第3.2节末尾添加以下段落：
| Consistent with Section 3.4.61 of X.509 (11/2008) [X.509], we note
| that use of self-issued certificates and self-signed certificates
| issued by entities other than CAs are outside the scope of this
| specification. Thus, for example, a web server or client might
| generate a self-signed certificate to identify itself. These
| certificates and how a relying party uses them to authenticate
| asserted identities are both outside the scope of RFC 5280.
| Consistent with Section 3.4.61 of X.509 (11/2008) [X.509], we note
| that use of self-issued certificates and self-signed certificates
| issued by entities other than CAs are outside the scope of this
| specification. Thus, for example, a web server or client might
| generate a self-signed certificate to identify itself. These
| certificates and how a relying party uses them to authenticate
| asserted identities are both outside the scope of RFC 5280.
RFC 5280, Section 4.2.1.4, the tenth paragraph says:
RFC 5280第4.2.1.4节第十段规定：
An explicitText field includes the textual statement directly in
the certificate. The explicitText field is a string with a
maximum size of 200 characters. Conforming CAs SHOULD use the
| UTF8String encoding for explicitText, but MAY use IA5String.
| Conforming CAs MUST NOT encode explicitText as VisibleString or
| BMPString. The explicitText string SHOULD NOT include any control
An explicitText field includes the textual statement directly in
the certificate. The explicitText field is a string with a
maximum size of 200 characters. Conforming CAs SHOULD use the
| UTF8String encoding for explicitText, but MAY use IA5String.
| Conforming CAs MUST NOT encode explicitText as VisibleString or
| BMPString. The explicitText string SHOULD NOT include any control
| characters (e.g., U+0000 to U+001F and U+007F to U+009F). When | the UTF8String encoding is used, all character sequences SHOULD be normalized according to Unicode normalization form C (NFC) [NFC].
|字符（例如，U+0000到U+001F和U+007F到U+009F）。当使用UTF8String编码时，所有字符序列都应根据Unicode规范化格式C（NFC）[NFC]进行规范化。
This paragraph is replaced with:
本段改为：
An explicitText field includes the textual statement directly in
the certificate. The explicitText field is a string with a
maximum size of 200 characters. Conforming CAs SHOULD use the
| UTF8String encoding for explicitText. VisibleString or BMPString
| are acceptable but less preferred alternatives. Conforming CAs
| MUST NOT encode explicitText as IA5String. The explicitText string
| SHOULD NOT include any control characters (e.g., U+0000 to U+001F
| and U+007F to U+009F). When the UTF8String or BMPString encoding
is used, all character sequences SHOULD be normalized according
to Unicode normalization form C (NFC) [NFC].
An explicitText field includes the textual statement directly in
the certificate. The explicitText field is a string with a
maximum size of 200 characters. Conforming CAs SHOULD use the
| UTF8String encoding for explicitText. VisibleString or BMPString
| are acceptable but less preferred alternatives. Conforming CAs
| MUST NOT encode explicitText as IA5String. The explicitText string
| SHOULD NOT include any control characters (e.g., U+0000 to U+001F
| and U+007F to U+009F). When the UTF8String or BMPString encoding
is used, all character sequences SHOULD be normalized according
to Unicode normalization form C (NFC) [NFC].
4. Update to RFC 5280, Section 6.2: "Using the Path Validation Algorithm"
4. 更新至RFC 5280，第6.2节：“使用路径验证算法”
RFC 5280, Section 6.2, the third paragraph says:
RFC 5280第6.2节第三段规定：
Where a CA distributes self-signed certificates to specify trust
anchor information, certificate extensions can be used to specify
recommended inputs to path validation. For example, a policy
constraints extension could be included in the self-signed
certificate to indicate that paths beginning with this trust anchor
should be trusted only for the specified policies. Similarly, a name
constraints extension could be included to indicate that paths
beginning with this trust anchor should be trusted only for the
specified name spaces. The path validation algorithm presented in
Section 6.1 does not assume that trust anchor information is provided
in self-signed certificates and does not specify processing rules for
| additional information included in such certificates.
| Implementations that use self-signed certificates to specify trust
| anchor information are free to process or ignore such information.
Where a CA distributes self-signed certificates to specify trust
anchor information, certificate extensions can be used to specify
recommended inputs to path validation. For example, a policy
constraints extension could be included in the self-signed
certificate to indicate that paths beginning with this trust anchor
should be trusted only for the specified policies. Similarly, a name
constraints extension could be included to indicate that paths
beginning with this trust anchor should be trusted only for the
specified name spaces. The path validation algorithm presented in
Section 6.1 does not assume that trust anchor information is provided
in self-signed certificates and does not specify processing rules for
| additional information included in such certificates.
| Implementations that use self-signed certificates to specify trust
| anchor information are free to process or ignore such information.
This paragraph is replaced with:
本段改为：
Where a CA distributes self-signed certificates to specify trust anchor information, certificate extensions can be used to specify recommended inputs to path validation. For example, a policy constraints extension could be included in the self-signed certificate to indicate that paths beginning with this trust anchor should be trusted only for the specified policies. Similarly, a name constraints extension could be included to indicate that paths beginning with this trust anchor should be trusted only for the specified name spaces. The path validation algorithm presented in
当CA分发自签名证书以指定信任锚信息时，可以使用证书扩展来指定路径验证的建议输入。例如，自签名证书中可以包含一个策略约束扩展，以指示以该信任锚点开头的路径只应为指定的策略受信任。类似地，可以包括名称约束扩展，以指示以该信任锚点开头的路径只应在指定的名称空间中受信任。中介绍的路径验证算法
Section 6.1 does not assume that trust anchor information is provided
| in self-signed certificates and does not specify processing rules for
| additional information included in such certificates.
| However, [RFC5914] defines several formats for representing trust
| anchor information, including self-signed certificates, and [RFC5937]
| provides an example of how such information may be used to initialize
| the path validation inputs. Implementations are free to make use of
| any additional information that is included in a trust anchor
| representation, or to ignore such information.
Section 6.1 does not assume that trust anchor information is provided
| in self-signed certificates and does not specify processing rules for
| additional information included in such certificates.
| However, [RFC5914] defines several formats for representing trust
| anchor information, including self-signed certificates, and [RFC5937]
| provides an example of how such information may be used to initialize
| the path validation inputs. Implementations are free to make use of
| any additional information that is included in a trust anchor
| representation, or to ignore such information.
5. Update to RFC 5280, Section 7.3: "Internationalized Domain Names in Distinguished Names"
5. 更新RFC 5280，第7.3节：“专有名称中的国际化域名”
RFC 5280, Section 7.3, the first paragraph says:
RFC 5280第7.3节第一段规定：
Domain Names may also be represented as distinguished names using
domain components in the subject field, the issuer field, the
subjectAltName extension, or the issuerAltName extension. As with
the dNSName in the GeneralName type, the value of this attribute is
defined as an IA5String. Each domainComponent attribute represents a
single label. To represent a label from an IDN in the distinguished
name, the implementation MUST perform the "ToASCII" label conversion
| specified in Section 4.1 of RFC 3490. The label SHALL be considered
| a "stored string". That is, the AllowUnassigned flag SHALL NOT be
| set.
Domain Names may also be represented as distinguished names using
domain components in the subject field, the issuer field, the
subjectAltName extension, or the issuerAltName extension. As with
the dNSName in the GeneralName type, the value of this attribute is
defined as an IA5String. Each domainComponent attribute represents a
single label. To represent a label from an IDN in the distinguished
name, the implementation MUST perform the "ToASCII" label conversion
| specified in Section 4.1 of RFC 3490. The label SHALL be considered
| a "stored string". That is, the AllowUnassigned flag SHALL NOT be
| set.
This paragraph is replaced with:
本段改为：
Domain Names may also be represented as distinguished names using
domain components in the subject field, the issuer field, the
subjectAltName extension, or the issuerAltName extension. As with
the dNSName in the GeneralName type, the value of this attribute is
defined as an IA5String. Each domainComponent attribute represents a
single label. To represent a label from an IDN in the distinguished
name, the implementation MUST perform the "ToASCII" label conversion
| specified in Section 4.1 of RFC 3490 with the UseSTD3ASCIIRules flag
| set. The label SHALL be considered a "stored string". That is, the
| AllowUnassigned flag SHALL NOT be set. The conversion process is the
| same as is performed in step 4 in Section 7.2.
Domain Names may also be represented as distinguished names using
domain components in the subject field, the issuer field, the
subjectAltName extension, or the issuerAltName extension. As with
the dNSName in the GeneralName type, the value of this attribute is
defined as an IA5String. Each domainComponent attribute represents a
single label. To represent a label from an IDN in the distinguished
name, the implementation MUST perform the "ToASCII" label conversion
| specified in Section 4.1 of RFC 3490 with the UseSTD3ASCIIRules flag
| set. The label SHALL be considered a "stored string". That is, the
| AllowUnassigned flag SHALL NOT be set. The conversion process is the
| same as is performed in step 4 in Section 7.2.
This document modifies the Security Considerations section of RFC 5280 as follows. The fifth paragraph of the Security Considerations section of RFC 5280 says:
本文件对RFC 5280的安全注意事项部分进行了如下修改。RFC 5280安全注意事项部分的第五段指出：
The protection afforded private keys is a critical security factor.
On a small scale, failure of users to protect their private keys will
permit an attacker to masquerade as them or decrypt their personal
information. On a larger scale, compromise of a CA's private signing
| key may have a catastrophic effect. If an attacker obtains the
| private key unnoticed, the attacker may issue bogus certificates and
| CRLs. Existence of bogus certificates and CRLs will undermine
| confidence in the system. If such a compromise is detected, all
| certificates issued to the compromised CA MUST be revoked, preventing
| services between its users and users of other CAs. Rebuilding after
| such a compromise will be problematic, so CAs are advised to
| implement a combination of strong technical measures (e.g., tamper-
| resistant cryptographic modules) and appropriate management
| procedures (e.g., separation of duties) to avoid such an incident.
The protection afforded private keys is a critical security factor.
On a small scale, failure of users to protect their private keys will
permit an attacker to masquerade as them or decrypt their personal
information. On a larger scale, compromise of a CA's private signing
| key may have a catastrophic effect. If an attacker obtains the
| private key unnoticed, the attacker may issue bogus certificates and
| CRLs. Existence of bogus certificates and CRLs will undermine
| confidence in the system. If such a compromise is detected, all
| certificates issued to the compromised CA MUST be revoked, preventing
| services between its users and users of other CAs. Rebuilding after
| such a compromise will be problematic, so CAs are advised to
| implement a combination of strong technical measures (e.g., tamper-
| resistant cryptographic modules) and appropriate management
| procedures (e.g., separation of duties) to avoid such an incident.
This paragraph is replaced with:
本段改为：
The protection afforded private keys is a critical security factor.
On a small scale, failure of users to protect their private keys will
permit an attacker to masquerade as them or decrypt their personal
information. On a larger scale, compromise of a CA's private signing
key may have a catastrophic effect.
|
| If an attacker obtains the private key of a CA unnoticed, the
| attacker may issue bogus certificates and CRLs. Even if an attacker
| is unable to obtain a copy of a CA's private key, the attacker may be
| able to issue bogus certificates and CRLs by making unauthorized use
| of the CA's workstation or of an RA's workstation. Such an attack
| may be the result of an attacker obtaining unauthorized access to the
| workstation, either locally or remotely, or may be the result of
| inappropriate activity by an insider. Existence of bogus
| certificates and CRLs will undermine confidence in the system. Among
| many other possible attacks, the attacker may issue bogus
| certificates that have the same subject names as legitimate
| certificates in order impersonate legitimate certificate subjects.
| This could include bogus CA certificates in which the subject names
| in the bogus certificates match the names under which legitimate CAs
| issue certificates and CRLs. This would allow the attacker to issue
| bogus certificates and CRLs that have the same issuer names, and
| possibly the same serial numbers, as certificates and CRLs issued by
| legitimate CAs.
The protection afforded private keys is a critical security factor.
On a small scale, failure of users to protect their private keys will
permit an attacker to masquerade as them or decrypt their personal
information. On a larger scale, compromise of a CA's private signing
key may have a catastrophic effect.
|
| If an attacker obtains the private key of a CA unnoticed, the
| attacker may issue bogus certificates and CRLs. Even if an attacker
| is unable to obtain a copy of a CA's private key, the attacker may be
| able to issue bogus certificates and CRLs by making unauthorized use
| of the CA's workstation or of an RA's workstation. Such an attack
| may be the result of an attacker obtaining unauthorized access to the
| workstation, either locally or remotely, or may be the result of
| inappropriate activity by an insider. Existence of bogus
| certificates and CRLs will undermine confidence in the system. Among
| many other possible attacks, the attacker may issue bogus
| certificates that have the same subject names as legitimate
| certificates in order impersonate legitimate certificate subjects.
| This could include bogus CA certificates in which the subject names
| in the bogus certificates match the names under which legitimate CAs
| issue certificates and CRLs. This would allow the attacker to issue
| bogus certificates and CRLs that have the same issuer names, and
| possibly the same serial numbers, as certificates and CRLs issued by
| legitimate CAs.
The following text is added to the end of the Security Considerations section of 5280:
5280安全注意事项章节末尾添加了以下内容：
| One-way hash functions are commonly used to generate key identifier
| values (AKI and SKI), e.g., as described in Sections 4.1.1 and 4.1.2.
| However, none of the security properties of such functions are
| required for this context.
| One-way hash functions are commonly used to generate key identifier
| values (AKI and SKI), e.g., as described in Sections 4.1.1 and 4.1.2.
| However, none of the security properties of such functions are
| required for this context.
[RFC5914] Housley, R., Ashmore, S., and C. Wallace, "Trust Anchor Format", RFC 5914, June 2010.
[RFC5914]Housley，R.，Ashmore，S.，和C.Wallace，“信任锚格式”，RFC 59142010年6月。
[RFC5937] Ashmore, S. and C. Wallace, "Using Trust Anchor Constraints during Certification Path Processing", RFC 5937, August 2010.
[RFC5937]Ashmore，S.和C.Wallace，“在认证路径处理期间使用信任锚约束”，RFC 5937，2010年8月。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[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。
[RFC5914] Housley, R., Ashmore, S., and C. Wallace, "Trust Anchor Format", RFC 5914, June 2010.
[RFC5914]Housley，R.，Ashmore，S.，和C.Wallace，“信任锚格式”，RFC 59142010年6月。
[X.509] ITU-T Recommendation X.509 (2008) | ISO/IEC 9594-8:2008, Information Technology - Open Systems Interconnection - The Directory: Public-key and attribute certificate frameworks.
[X.509]ITU-T建议X.509（2008）| ISO/IEC 9594-8:2008，信息技术-开放系统互连-目录：公钥和属性证书框架。
[RFC5937] Ashmore, S. and C. Wallace, "Using Trust Anchor Constraints during Certification Path Processing", RFC 5937, August 2010.
[RFC5937]Ashmore，S.和C.Wallace，“在认证路径处理期间使用信任锚约束”，RFC 5937，2010年8月。
[Prins] Prins, J. R., "DigiNotar Certificate Authority breach 'Operation Black Tulip'", September 2011, <http://www.rijksoverheid.nl/bestanden/ documenten-en-publicaties/rapporten/2011/ 09/05/diginotar-public-report-version-1/ rapport-fox-it-operation-black-tulip-v1-0.pdf>.
[Prins]Prins，J.R.，“DigiNotar证书颁发机构违反‘黑郁金香行动’”，2011年9月<http://www.rijksoverheid.nl/bestanden/ documenten publications/reporten/2011/09/05/diginotar-public-report-version-1/report-fox-it-operation-black-tulip-v1-0.pdf>。
[NFC] Davis, M. and M. Duerst, "Unicode Standard Annex #15: Unicode Normalization Forms", October 2006, <http://www.unicode.org/reports/tr15/>.
[NFC]Davis，M.和M.Duerst，“Unicode标准附件#15：Unicode规范化格式”，2006年10月<http://www.unicode.org/reports/tr15/>.
David Cooper is acknowledged for his fine work in editing previous versions of this document.
David Cooper因其在编辑本文档以前版本方面的出色工作而受到认可。
Author's Address
作者地址
Peter E. Yee AKAYLA 7150 Moorland Drive Clarksville, MD 21029 USA EMail: peter@akayla.com
Peter E.Yee AKAYLA美国马里兰州克拉克斯维尔摩尔兰大道7150号邮编：21029电子邮件：peter@akayla.com