draft-ietf-httpbis-legally-restricted-status-01.txt   draft-ietf-httpbis-legally-restricted-status-02.txt 
HTTP Working Group T. Bray HTTP Working Group T. Bray
Internet-Draft Textuality Internet-Draft Textuality
Updates: 2616 (if approved) June 28, 2015 Intended status: Standards Track August 31, 2015
Intended status: Standards Track Expires: March 3, 2016
Expires: December 30, 2015
An HTTP Status Code to Report Legal Obstacles An HTTP Status Code to Report Legal Obstacles
draft-ietf-httpbis-legally-restricted-status-01 draft-ietf-httpbis-legally-restricted-status-02
Abstract Abstract
This document specifies a Hypertext Transfer Protocol (HTTP) status This document specifies a Hypertext Transfer Protocol (HTTP) status
code for use when resource access is denied as a consequence of legal code for use when resource access is denied as a consequence of legal
demands. demands.
Editorial Note (To be removed by RFC Editor before publication) Editorial Note (To be removed by RFC Editor before publication)
Discussion of this draft takes place on the HTTPBIS working group Discussion of this draft takes place on the HTTPBIS working group
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 30, 2015. This Internet-Draft will expire on March 3, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 2
3. 451 Unavailable For Legal Reasons . . . . . . . . . . . . . . 2 3. 451 Unavailable For Legal Reasons . . . . . . . . . . . . . . 2
4. Security Considerations . . . . . . . . . . . . . . . . . . . 3 4. Identifying Blocking Entities . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. Normative References . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 4 7. Normative References . . . . . . . . . . . . . . . . . . . . 4
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction 1. Introduction
This document specifies a Hypertext Transfer Protocol (HTTP) status This document specifies a Hypertext Transfer Protocol (HTTP) status
code for use when a server operator has a received a legal demand to code for use when a server operator has a received a legal demand to
deny access to a resource. deny access to a resource.
This status code may be used to provide transparency in circumstances This status code can be used to provide transparency in circumstances
where issues of law or public policy affect server operations. This where issues of law or public policy affect server operations. This
transparency may be beneficial both to these operators and to end transparency may be beneficial both to these operators and to end
users. users.
[RFC4924] discusses the forces working against transparent operation [RFC4924] discusses the forces working against transparent operation
of the Internet; these clearly include legal interventions to of the Internet; these clearly include legal interventions to
restrict access to content. As that document notes, and as Section 4 restrict access to content. As that document notes, and as Section 4
of [RFC4084] states, such restrictions should be made explicit. of [RFC4084] states, such restrictions should be made explicit.
Feedback should occur on the ietf-http-wg@w3.org mailing list. Feedback should occur on the ietf-http-wg@w3.org mailing list.
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
3. 451 Unavailable For Legal Reasons 3. 451 Unavailable For Legal Reasons
This status code indicates that the server is denying access to the This status code indicates that the server is denying access to the
resource as a consequence of a legal demand. resource as a consequence of a legal demand.
The server in question may not be an origin server. This type of The server in question might not be an origin server. This type of
legal demand typically most directly affects the operations of ISPs legal demand typically most directly affects the operations of ISPs
and search engines. and search engines.
Responses using this status code SHOULD include an explanation, in Responses using this status code SHOULD include an explanation, in
the response body, of the details of the legal demand: the party the response body, of the details of the legal demand: the party
making it, the applicable legislation or regulation, and what classes making it, the applicable legislation or regulation, and what classes
of person and resource it applies to. For example: of person and resource it applies to. For example:
HTTP/1.1 451 Unavailable For Legal Reasons HTTP/1.1 451 Unavailable For Legal Reasons
Content-Type: text/html Content-Type: text/html
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is possible that if the legal demands were removed, a request for the is possible that if the legal demands were removed, a request for the
resource still might not succeed. resource still might not succeed.
Note that in many cases clients can still access the denied resource Note that in many cases clients can still access the denied resource
by using technical countermeasures such as a VPN or the Tor network. by using technical countermeasures such as a VPN or the Tor network.
A 451 response is cacheable by default; i.e., unless otherwise A 451 response is cacheable by default; i.e., unless otherwise
indicated by the method definition or explicit cache controls; see indicated by the method definition or explicit cache controls; see
[RFC7234]. [RFC7234].
4. Security Considerations 4. Identifying Blocking Entities
4.1. 451 Unavailable for Legal Reasons 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 which could choose to deny access, for example ISPs,
cache providers, and DNS servers.
It is useful, when legal blockages occur, to be able to identify the
entities actually implementing the blocking.
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".
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.
5. Security Considerations
5.1. 451 Unavailable for Legal Reasons
The 451 status code is optional; clients cannot rely upon its use. The 451 status code is optional; clients cannot rely upon its use.
It is possible that certain legal authorities may wish to avoid It is possible that certain legal authorities might wish to avoid
transparency, and not only demand the restriction of access to transparency, and not only demand the restriction of access to
certain resources, but also avoid disclosing that the demand was certain resources, but also avoid disclosing that the demand was
made. made.
5. IANA Considerations 6. IANA Considerations
The HTTP Status Codes Registry should be updated with the following The HTTP Status Codes Registry should be updated with the following
entries: entry:
o Code: 451 o Code: 451
o Description: Unavailable for Legal Reasons o Description: Unavailable for Legal Reasons
o Specification: [ this document ] o Specification: [ this document ]
6. Normative References 7. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/ Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
RFC2119, March 1997, RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <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>.
[RFC4084] Klensin, J., "Terminology for Describing Internet [RFC4084] Klensin, J., "Terminology for Describing Internet
Connectivity", BCP 104, RFC 4084, DOI 10.17487/RFC4084, Connectivity", BCP 104, RFC 4084, DOI 10.17487/RFC4084,
May 2005, <http://www.rfc-editor.org/info/rfc4084>. May 2005, <http://www.rfc-editor.org/info/rfc4084>.
[RFC4924] Aboba, B. and E. Davies, "Reflections on Internet [RFC4924] Aboba, B., Ed. and E. Davies, "Reflections on Internet
Transparency", RFC 4924, DOI 10.17487/RFC4924, July 2007, Transparency", RFC 4924, DOI 10.17487/RFC4924, July 2007,
<http://www.rfc-editor.org/info/rfc4924>. <http://www.rfc-editor.org/info/rfc4924>.
[RFC7234] Fielding, R., Nottingham, M., and J. Reschke, "Hypertext [RFC5988] Nottingham, M., "Web Linking", RFC 5988, DOI 10.17487/
Transfer Protocol (HTTP/1.1): Caching", RFC 7234, DOI RFC5988, October 2010,
10.17487/RFC7234, June 2014, <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>. <http://www.rfc-editor.org/info/rfc7234>.
Appendix A. Acknowledgements Appendix A. Acknowledgements
Thanks to Terence Eden, who observed that the existing status code Thanks to Terence Eden, who observed that the existing status code
403 was not really suitable for this situation, and suggested the 403 was not really suitable for this situation, and suggested the
creation of a new status code. creation of a new status code.
Thanks also to Ray Bradbury. Thanks also to Ray Bradbury.
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