Supporting Redirection for DNS Queries over HTTPS (DoH)
draft-btw-dprive-rfc8484-clarification-00

Document Type Active Internet-Draft (individual)
Authors Mohamed Boucadair  , Neil Cook  , Tirumaleswar Reddy.K  , Dan Wing 
Last updated 2020-08-27
Replaces draft-btw-add-rfc8484-clarification
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ADD                                                         M. Boucadair
Internet-Draft                                                    Orange
Updates: 8484 (if approved)                                      N. Cook
Intended status: Standards Track                            Open-Xchange
Expires: February 28, 2021                                      T. Reddy
                                                                  McAfee
                                                                 D. Wing
                                                                  Citrix
                                                         August 27, 2020

        Supporting Redirection for DNS Queries over HTTPS (DoH)
               draft-btw-dprive-rfc8484-clarification-00

Abstract

   This document clarifies whether DNS-over-HTTPS (DoH) redirection is
   allowed, describes potential issues with redirection in DoH, and
   proposes how DoH redirection might be performed.

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
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on February 28, 2021.

Copyright Notice

   Copyright (c) 2020 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
   (https://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

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   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Discussion  . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  RFC8484 Update  . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Issues with Redirection in DoH  . . . . . . . . . . . . . . .   4
   6.  Service-Level Redirect  . . . . . . . . . . . . . . . . . . .   6
     6.1.  Well-Known URI  . . . . . . . . . . . . . . . . . . . . .   6
   7.  Resource-Level Redirect . . . . . . . . . . . . . . . . . . .   7
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
     9.1.  resinfo Well-Known URI Suffix . . . . . . . . . . . . . .   8
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   8
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     11.1.  Normative References . . . . . . . . . . . . . . . . . .   9
     11.2.  Informative References . . . . . . . . . . . . . . . . .  10
   Appendix A.  Extending Alternative Services . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   This document clarifies the intent of DNS-over-HTTPS (DoH) [RFC8484]
   whether redirection is allowed (Section 4), potential issues with
   redirection in DoH (Section 5) and subsequently makes some proposals
   for how service-level (Section 6) and resource-level (Section 7)
   redirection might be performed.

   This document adheres to Section 4.3 of [I-D.ietf-httpbis-bcp56bis]
   which discusses the need for protocols using HTTP to specify redirect
   handling to avoid interoperability problems.

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119][RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   "A/AAAA" is used to refer to "A and/or AAAA records".

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3.  Discussion

   [RFC8484] indicates that the support of HTTP [RFC7540] redirection is
   one of DoH design goals (Section 1):
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