DNS Privacy Considerations
draft-ietf-dprive-rfc7626-bis-04

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dprive                                                     S. Bortzmeyer
Internet-Draft                                                     AFNIC
Obsoletes: 7626 (if approved)                               S. Dickinson
Intended status: Informational                                Sinodun IT
Expires: July 19, 2020                                  January 16, 2020

                       DNS Privacy Considerations
                    draft-ietf-dprive-rfc7626-bis-04

Abstract

   This document describes the privacy issues associated with the use of
   the DNS by Internet users.  It is intended to be an analysis of the
   present situation and does not prescribe solutions.  This document
   obsoletes RFC 7626.

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 July 19, 2020.

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
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Bortzmeyer & Dickinson    Expires July 19, 2020                 [Page 1]
Internet-Draft         DNS Privacy Considerations           January 2020

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Risks . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  The Alleged Public Nature of DNS Data . . . . . . . . . .   5
     3.2.  Data in the DNS Request . . . . . . . . . . . . . . . . .   6
       3.2.1.  Data in the DNS payload . . . . . . . . . . . . . . .   7
     3.3.  Cache Snooping  . . . . . . . . . . . . . . . . . . . . .   8
     3.4.  On the Wire . . . . . . . . . . . . . . . . . . . . . . .   8
       3.4.1.  Unencrypted Transports  . . . . . . . . . . . . . . .   8
       3.4.2.  Encrypted Transports  . . . . . . . . . . . . . . . .  10
     3.5.  In the Servers  . . . . . . . . . . . . . . . . . . . . .  11
       3.5.1.  In the Recursive Resolvers  . . . . . . . . . . . . .  11
       3.5.2.  In the Authoritative Name Servers . . . . . . . . . .  15
     3.6.  Re-identification and Other Inferences  . . . . . . . . .  16
     3.7.  More Information  . . . . . . . . . . . . . . . . . . . .  17
   4.  Actual "Attacks"  . . . . . . . . . . . . . . . . . . . . . .  17
   5.  Legalities  . . . . . . . . . . . . . . . . . . . . . . . . .  18
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  18
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  18
   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  18
   9.  Changelog . . . . . . . . . . . . . . . . . . . . . . . . . .  19
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  21
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  21
     10.2.  Informative References . . . . . . . . . . . . . . . . .  21
     10.3.  URIs . . . . . . . . . . . . . . . . . . . . . . . . . .  27
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  27

1.  Introduction

   This document is an analysis of the DNS privacy issues, in the spirit
   of Section 8 of [RFC6973].

   The Domain Name System (DNS) is specified in [RFC1034], [RFC1035],
   and many later RFCs, which have never been consolidated.  It is one
   of the most important infrastructure components of the Internet and
   often ignored or misunderstood by Internet users (and even by many
   professionals).  Almost every activity on the Internet starts with a
   DNS query (and often several).  Its use has many privacy implications
   and this document is an attempt at a comprehensive and accurate list.

   Let us begin with a simplified reminder of how the DNS works (See
   also [RFC8499]).  A client, the stub resolver, issues a DNS query to
   a server, called the recursive resolver (also called caching resolver