Padding Policy for EDNS(0)
draft-ietf-dprive-padding-policy-01

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Last updated 2017-07-03
Replaces draft-mayrhofer-dprive-padding-profile
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Network Working Group                                       A. Mayrhofer
Internet-Draft                                               nic.at GmbH
Intended status: Standards Track                            July 3, 2017
Expires: January 4, 2018

                       Padding Policy for EDNS(0)
                  draft-ietf-dprive-padding-policy-01

Abstract

   RFC 7830 specifies the EDNS0 'Padding' option, but does not specify
   the length of padding to be used in specific applications.  This memo
   lists the possible options ("Padding Policies"), discusses the
   implications of each of these options, and provides a recommended
   option.

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
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 4, 2018.

Copyright Notice

   Copyright (c) 2017 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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   described in the Simplified BSD License.

Mayrhofer                Expires January 4, 2018                [Page 1]
Internet-Draft      draft-ietf-dprive-padding-policy           July 2017

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  General Guidance  . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Padding Strategies  . . . . . . . . . . . . . . . . . . . . .   3
     4.1.  No Padding  . . . . . . . . . . . . . . . . . . . . . . .   3
     4.2.  Fixed Length Padding  . . . . . . . . . . . . . . . . . .   3
     4.3.  Block Length Padding  . . . . . . . . . . . . . . . . . .   4
     4.4.  Random Length Padding . . . . . . . . . . . . . . . . . .   4
     4.5.  Random Block Length Padding . . . . . . . . . . . . . . .   5
   5.  Recommended Strategy  . . . . . . . . . . . . . . . . . . . .   5
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   6
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   9.  Changes . . . . . . . . . . . . . . . . . . . . . . . . . . .   6
     9.1.  draft-ietf-dprive-padding-policy-01 . . . . . . . . . . .   6
     9.2.  draft-ietf-dprive-padding-policy-00 . . . . . . . . . . .   6
     9.3.  draft-mayrhofer-dprive-padding-profiles-00  . . . . . . .   6
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     10.1.  Normative References . . . . . . . . . . . . . . . . . .   6
     10.2.  Informative References . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   RFC 7830 [RFC7830] specifies the Extensions Mechanisms for DNS
   (EDNS(0)) "Padding" option, which allows DNS clients and servers to
   artificially increase the size of a DNS message by a variable number
   of bytes, hampering size-based correlation of encrypted DNS messages.

   However, RFC 7830 deliberately does not specify the actual length of
   padding to be used.  This memo discusses options regarding the actual
   size of padding, lists advantages and disadvantages of each of these
   "Padding Strategies", and provides a recommended strategy (TODO
   pending concensus of the working group!)

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
   [RFC2119].
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