Forwarded HTTP Extension
draft-ietf-appsawg-http-forwarded-10

Network Working Group                                       A. Petersson
Internet-Draft                                                M. Nilsson
Intended status: Standards Track                          Opera Software
Expires: April 12, 2013                                  October 9, 2012

                        Forwarded HTTP Extension
                  draft-ietf-appsawg-http-forwarded-10

Abstract

   This document defines an HTTP extension header field that allows
   proxy components to disclose information lost in the proxying
   process, for example, the originating IP address of a request or IP
   address of the proxy on the user-agent-facing interface.  In a path
   of proxying components, this makes it possible to arrange it so that
   each subsequent component will have access to, for example, all IP
   addresses used in the chain of proxied HTTP requests.

   This document also specifies guidelines for a proxy administrator to
   anonymize the origin of a request.

Status of this Memo

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

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on April 12, 2013.

Copyright Notice

   Copyright (c) 2012 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

Petersson & Nilsson      Expires April 12, 2013                 [Page 1]
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   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.

Petersson & Nilsson      Expires April 12, 2013                 [Page 2]
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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Notational Conventions . . . . . . . . . . . . . . . . . . . .  5
   3.  Syntax Notations . . . . . . . . . . . . . . . . . . . . . . .  5
   4.  Forwarded HTTP Header Field  . . . . . . . . . . . . . . . . .  5
   5.  Parameters . . . . . . . . . . . . . . . . . . . . . . . . . .  6
     5.1.  Forwarded By . . . . . . . . . . . . . . . . . . . . . . .  7
     5.2.  Forwarded For  . . . . . . . . . . . . . . . . . . . . . .  7
     5.3.  Forwarded Host . . . . . . . . . . . . . . . . . . . . . .  8
     5.4.  Forwarded Proto  . . . . . . . . . . . . . . . . . . . . .  8
     5.5.  Extensions . . . . . . . . . . . . . . . . . . . . . . . .  8
   6.  Node Identifiers . . . . . . . . . . . . . . . . . . . . . . .  8
     6.1.  IPv4 and IPv6 Identifiers  . . . . . . . . . . . . . . . . 10
     6.2.  The "unknown" Identifier . . . . . . . . . . . . . . . . . 10
     6.3.  Obfuscated Identifier  . . . . . . . . . . . . . . . . . . 10
   7.  Implementation Considerations  . . . . . . . . . . . . . . . . 10
     7.1.  HTTP Lists . . . . . . . . . . . . . . . . . . . . . . . . 10
     7.2.  Header Field Preservation  . . . . . . . . . . . . . . . . 11
     7.3.  Relation to Via  . . . . . . . . . . . . . . . . . . . . . 11
     7.4.  Transition . . . . . . . . . . . . . . . . . . . . . . . . 11
     7.5.  Example Usage  . . . . . . . . . . . . . . . . . . . . . . 12
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 12
     8.1.  Header Validity and Integrity  . . . . . . . . . . . . . . 13
     8.2.  Information Leak . . . . . . . . . . . . . . . . . . . . . 13
     8.3.  Privacy Considerations . . . . . . . . . . . . . . . . . . 13
   9.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 14
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 15
     10.2. Informative References . . . . . . . . . . . . . . . . . . 16