Mark Andrews
INTERNET DRAFT                                                     CSIRO
Expires: September 1996                                       March                                         May 1996
Updates RFC-1035

                    ASCII Encoding for Domain Names

                     draft-andrews-dns-ascii-00.txt

                     draft-andrews-dns-ascii-01.txt

1. Status of This Memo

   This document is an Internet Draft.  Internet Drafts are working
   documents of the Internet Engineering Task Force (IETF), its Areas,
   and its Working Groups.  Note that other groups may also distribute
   working documents as Internet Drafts.

   Internet Drafts are draft documents valid for a maximum of six
   months.  Internet Drafts may be updated, replaced, or obsoleted by
   other documents at any time.  It is not appropriate to use Internet
   Drafts as reference material or to cite them other than as a "working
   draft" or "work in progress."

   Please check the 1id-abstracts.txt listing contained in the internet-
   drafts Shadow Directories to learn the current status of any Internet
   Draft.

2. Abstract

   At the protocol level, DNS domain names and records may contain
   arbitrary binary data.  There is not however a standard way of
   representing these domains as ASCII strings. This RFC

   [RFC 1035 Section 5.1] describes how to encode domain names as a single
   character strings. It however allows non printable characters to be
   used. It also allows for encodings of text files which would not
   survive intact ftp ASCII string containing no white
   space. mode transfers, different end of line
   conventions. This document addresses these problems by stating where
   octal escapes MUST be used.

   While a applications MUST continue to read the full range as
   expressed by [RFC 1035 5.1]. They MUST emit only this selected
   subset.

3. Encoding

   Octets within the follow ranges are encoded as backslash followed by
   three octal digits, 0x00 - 0x08, 0x0b - 0x0c, 0x0e - 0x1f, 0x20, 0x7f - 0xff.

           e.g.
                   0x00, \000
                   0x1f, \177
                   0xff, \377

   Period (".") when NOT used as a domain separator is encoded as the
   sequence backslash period, e.g. "\.". Un-escaped periods indicate
   label separators.

   Backslash ("\") is encoded as two consecutive backslashes, e.g. "\\".

   The follow are special encoding for particular characters.

           0x09, "\t", Horizontal Tab
           0x0a, "\n", Newline
           0x0d, "\r", Carriage Return
           0x20, "\s",

   Double quotes ('"') should always be represented as backslash quote
   as a common nameserver implementation mis-parses strings containing
   quotes, e.g. '\"'.

   Semi-colon (";") should always be encoded as backslash semi-colon
   otherwise it will be interpreted as a comment. e.g. "\;".

   Space may be a literal space when the string is enclosed by double
   quotes.

   All other characters represent their literal ASCII encoding eighth
   bit not set.

4. Security

   This draft introduces no known security problems. It may however
   remove some latent security problems in applications where the
   encoding is NOT reversible leading to unexpected changes in domain
   names.

5.

4. References

   [RFC-1035]
      P. Mockapetris, ``DOMAIN NAMES - IMPLEMENTATION AND
      SPECIFICATION'', RFC-1035, ISI, November 1987.

6. Author's Address

   Mark Andrews
   CSIRO
   Division of Mathematics and Statistics
   Locked Bag 17
   North Ryde NSW 2113
   AUSTRALIA

   Mark.Andrews@dms.csiro.au [MA88]