HTTP Working GroupT. Bray
Internet-DraftTextuality
Updates: 2616 (if approved)April 19, 2015
Intended status: Standards Track
Expires: October 21, 2015

An HTTP Status Code to Report Legal Obstacles
draft-ietf-httpbis-legally-restricted-status-latest

Abstract

This document specifies a Hypertext Transfer Protocol (HTTP) status code for use when resource access is denied as a consequence of legal demands.

Editorial Note (To be removed by RFC Editor before publication)

Discussion of this draft takes place on the HTTPBIS working group mailing list (ietf-http-wg@w3.org), which is archived at <https://lists.w3.org/Archives/Public/ietf-http-wg/>.

Working Group information can be found at <https://tools.ietf.org/wg/httpbis/> and <http://httpwg.github.io/>; source code and issues list for this draft can be found at <https://github.com/httpwg/http-extensions>.

Status of this Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on October 21, 2015.

Copyright Notice

Copyright © 2015 IETF Trust and the persons identified as the document authors. All rights reserved.

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.


Table of Contents

1. Introduction

This document specifies a Hypertext Transfer Protocol (HTTP) status code for use when a server operator has a received a legal demand to deny access to a resource.

This status code may 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.

[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.

Feedback should occur on the ietf-http-wg@w3.org mailing list, although this draft is NOT a work item of the IETF HTTPbis Working Group.

2. Requirements

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].

3. 451 Unavailable For Legal Reasons

This status code indicates that the server is denying access to the resource as a consequence of a legal demand.

The server in question may not be an origin server. This type of legal demand typically most directly affects the operations of ISPs and search engines.

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:

HTTP/1.1 451 Unavailable For Legal Reasons
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>

The use of the 451 status code implies neither the existence nor non-existence 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.

Note that in many cases clients can still access the denied resource by using technical countermeasures such as a VPN or the Tor network.

4. Security Considerations

4.1 451 Unavailable for Legal Reasons

The 451 status code is optional; clients cannot rely upon its use. It is possible that certain legal authorities may wish to avoid transparency, and not only demand the restriction of access to certain resources, but also avoid disclosing that the demand was made.

5. IANA Considerations

The HTTP Status Codes Registry should be updated with the following entries:

6. Normative References

[RFC2119]Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels”, BCP 14, RFC 2119, March 1997, <http://www.rfc-editor.org/info/rfc2119>.
[RFC4084]Klensin, J., “Terminology for Describing Internet Connectivity”, BCP 104, RFC 4084, May 2005, <http://www.rfc-editor.org/info/rfc4084>.
[RFC4924]Aboba, B. and E. Davies, “Reflections on Internet Transparency”, RFC 4924, July 2007, <http://www.rfc-editor.org/info/rfc4924>.

Acknowledgements

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.

Thanks also to Ray Bradbury.

The author takes all responsibility for errors and omissions.

Author's Address

Tim Bray
Textuality
EMail: tbray@textuality.com
URI: http://www.tbray.org/ongoing/