Internet Engineering Task Force (IETF) T. Bray
Request for Comments: 7725 Textuality
Category: Standards Track February 2016
ISSN: 2070-1721
Internet Engineering Task Force (IETF) T. Bray
Request for Comments: 7725 Textuality
Category: Standards Track February 2016
ISSN: 2070-1721
An HTTP Status Code to Report Legal Obstacles
用于报告法律障碍的HTTP状态代码
Abstract
摘要
This document specifies a Hypertext Transfer Protocol (HTTP) status code for use when resource access is denied as a consequence of legal demands.
本文档指定了一个超文本传输协议（HTTP）状态代码，用于因法律要求而拒绝资源访问时使用。
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/rfc7725.
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/rfc7725.
Copyright Notice
版权公告
Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2016 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
2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 2
3. 451 Unavailable For Legal Reasons . . . . . . . . . . . . . . 2
4. Identifying Blocking Entities . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 2
3. 451 Unavailable For Legal Reasons . . . . . . . . . . . . . . 2
4. Identifying Blocking Entities . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
This document specifies a Hypertext Transfer Protocol (HTTP) status code for use when a server operator has received a legal demand to deny access to a resource or to a set of resources that includes the requested resource.
本文档指定了一个超文本传输协议（HTTP）状态代码，当服务器操作员收到拒绝访问资源或包括请求的资源的一组资源的合法请求时使用。
This status code can be used to provide transparency in circumstances where issues of law or public policy affect server operations. This transparency may be beneficial both to these operators and to end users.
此状态代码可用于在法律或公共政策问题影响服务器操作的情况下提供透明度。这种透明度可能对这些运营商和最终用户都有利。
[RFC4924] discusses the forces working against transparent operation of the Internet; these clearly include legal interventions to restrict access to content. As that document notes, and as Section 4 of [RFC4084] states, such restrictions should be made explicit.
[RFC4924]讨论了反对互联网透明运行的力量；这些措施显然包括限制内容访问的法律干预。如该文件所述，以及[RFC4084]第4节所述，此类限制应明确规定。
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 [RFC2119].
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照[RFC2119]中所述进行解释。
This status code indicates that the server is denying access to the resource as a consequence of a legal demand.
此状态代码表示由于法律要求，服务器拒绝访问资源。
The server in question might not be an origin server. This type of legal demand typically most directly affects the operations of ISPs and search engines.
有问题的服务器可能不是源服务器。这类法律要求通常最直接地影响ISP和搜索引擎的运营。
Responses using this status code SHOULD include an explanation, in the response body, of the details of the legal demand: the party making it, the applicable legislation or regulation, and what classes of person and resource it applies to. For example:
使用该身份代码的回复应包括在回复机构中解释法律要求的详细信息：提出法律要求的一方、适用的立法或法规，以及适用的人员和资源类别。例如：
HTTP/1.1 451 Unavailable For Legal Reasons
Link: <https://spqr.example.org/legislatione>; rel="blocked-by"
Content-Type: text/html
HTTP/1.1 451 Unavailable For Legal Reasons
Link: <https://spqr.example.org/legislatione>; rel="blocked-by"
Content-Type: text/html
<html>
<head><title>Unavailable For Legal Reasons</title></head>
<body>
<h1>Unavailable For Legal Reasons</h1>
<p>This request may not be serviced in the Roman Province
of Judea due to the Lex Julia Majestatis, which disallows
access to resources hosted on servers deemed to be
operated by the People's Front of Judea.</p>
</body>
</html>
<html>
<head><title>Unavailable For Legal Reasons</title></head>
<body>
<h1>Unavailable For Legal Reasons</h1>
<p>This request may not be serviced in the Roman Province
of Judea due to the Lex Julia Majestatis, which disallows
access to resources hosted on servers deemed to be
operated by the People's Front of Judea.</p>
</body>
</html>
The use of the 451 status code implies neither the existence nor nonexistence of the resource named in the request. That is to say, it is possible that if the legal demands were removed, a request for the resource still might not succeed.
使用451状态代码并不意味着请求中指定的资源存在或不存在。也就是说，如果法律要求被删除，对资源的请求可能仍然无法成功。
Note that in many cases clients can still access the denied resource by using technical countermeasures such as a VPN or the Tor network.
注意，在许多情况下，客户端仍然可以通过使用VPN或Tor网络等技术对策来访问被拒绝的资源。
A 451 response is cacheable by default, i.e., unless otherwise indicated by the method definition or explicit cache controls; see [RFC7234].
451响应在默认情况下是可缓存的，即，除非方法定义或显式缓存控件另有指示；见[RFC7234]。
As noted above, when an attempt to access a resource fails with status 451, the entity blocking access might or might not be the origin server. There are a variety of entities in the resource-access path that could choose to deny access -- for example, ISPs, cache providers, and DNS servers.
如上所述，当尝试访问资源失败且状态为451时，阻止访问的实体可能是源服务器，也可能不是。资源访问路径中有多种实体可以选择拒绝访问，例如ISP、缓存提供程序和DNS服务器。
It is useful, when legal blockages occur, to be able to identify the entities actually implementing the blocking.
当发生法律封锁时，能够识别实际实施封锁的实体非常有用。
When an entity blocks access to a resource and returns status 451, it SHOULD include a "Link" HTTP header field [RFC5988] whose value is a URI reference [RFC3986] identifying itself. When used for this purpose, the "Link" header field MUST have a "rel" parameter whose value is "blocked-by".
当实体阻止对资源的访问并返回状态451时，它应该包括一个“链接”HTTP头字段[RFC5988]，其值是标识自身的URI引用[RFC3986]。用于此目的时，“链接”标题字段必须有一个“rel”参数，其值为“blocked by”。
The intent is that the header be used to identify the entity actually implementing blockage, not any other entity mandating it. A human-readable response body, as discussed above, is the appropriate location for discussion of administrative and policy issues.
其目的是使用头来标识实际执行阻塞的实体，而不是任何其他强制执行阻塞的实体。如上所述，一个可读性强的回应机构是讨论行政和政策问题的适当场所。
Clients cannot rely upon the use of the 451 status code. It is possible that certain legal authorities might wish to avoid transparency, and not only demand the restriction of access to certain resources, but also avoid disclosing that the demand was made.
客户端不能依赖于使用451状态代码。某些法律当局可能希望避免透明度，不仅要求限制对某些资源的使用，而且还避免披露提出要求的事实。
The HTTP Status Codes Registry has been updated with the following entry:
HTTP状态代码注册表已更新为以下条目：
o Code: 451
o 代码：451
o Description: Unavailable For Legal Reasons
o 说明：由于法律原因无法使用
o Specification: RFC 7725
o 规格：RFC7725
The Link Relation Type Registry has been updated with the following entry:
链接关系类型注册表已更新为以下条目：
o Relation Name: blocked-by
o 关系名称：被阻止
o Description: Identifies the entity that blocks access to a resource following receipt of a legal demand.
o 描述：标识在收到合法请求后阻止访问资源的实体。
o Reference: RFC 7725
o 参考：RFC 7725
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <http://www.rfc-editor.org/info/rfc2119>.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，DOI 10.17487/RFC2119，1997年3月<http://www.rfc-editor.org/info/rfc2119>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, <http://www.rfc-editor.org/info/rfc3986>.
[RFC3986]Berners Lee，T.，Fielding，R.，和L.Masinter，“统一资源标识符（URI）：通用语法”，STD 66，RFC 3986，DOI 10.17487/RFC3986，2005年1月<http://www.rfc-editor.org/info/rfc3986>.
[RFC5988] Nottingham, M., "Web Linking", RFC 5988, DOI 10.17487/RFC5988, October 2010, <http://www.rfc-editor.org/info/rfc5988>.
[RFC5988]诺丁汉，M.，“网络链接”，RFC 5988，DOI 10.17487/RFC5988，2010年10月<http://www.rfc-editor.org/info/rfc5988>.
[RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching", RFC 7234, DOI 10.17487/RFC7234, June 2014, <http://www.rfc-editor.org/info/rfc7234>.
[RFC7234]Fielding，R.，Ed.，Nottingham，M.，Ed.，和J.Reschke，Ed.，“超文本传输协议（HTTP/1.1）：缓存”，RFC 7234，DOI 10.17487/RFC72342014年6月<http://www.rfc-editor.org/info/rfc7234>.
[RFC4084] Klensin, J., "Terminology for Describing Internet Connectivity", BCP 104, RFC 4084, DOI 10.17487/RFC4084, May 2005, <http://www.rfc-editor.org/info/rfc4084>.
[RFC4084]Klensin，J.，“描述互联网连接的术语”，BCP 104，RFC 4084，DOI 10.17487/RFC4084，2005年5月<http://www.rfc-editor.org/info/rfc4084>.
[RFC4924] Aboba, B., Ed. and E. Davies, "Reflections on Internet Transparency", RFC 4924, DOI 10.17487/RFC4924, July 2007, <http://www.rfc-editor.org/info/rfc4924>.
[RFC4924]Aboba，B.，Ed.和E.Davies，“关于互联网透明度的思考”，RFC 4924，DOI 10.17487/RFC4924，2007年7月<http://www.rfc-editor.org/info/rfc4924>.
Acknowledgements
致谢
Thanks to Terence Eden, who observed that the existing status code 403 was not really suitable for this situation, and suggested the creation of a new status code.
感谢特伦斯·伊登（Terence Eden），他发现现有的状态代码403并不适合这种情况，并建议创建一个新的状态代码。
Thanks also to Ray Bradbury.
也要感谢雷·布拉德伯里。
Author's Address
作者地址
Tim Bray Textuality
蒂姆·布雷
Email: tbray@textuality.com
URI: http://www.tbray.org/ongoing/
Email: tbray@textuality.com
URI: http://www.tbray.org/ongoing/