The application/zlib and application/gzip media types
draft-levine-application-gzip-00

Network Working Group                                        J.R. Levine
Internet-Draft                                      Taughannock Networks
Intended status: Informational                             February 2012
Expires: August 14, 2012

         The application/zlib and application/gzip media types
                    draft-levine-application-gzip-00

Abstract

   This document defines the 'application/gzip' and 'application/zlib'
   media types for compressed data using the gzip and zlib compression
   formats.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
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   This Internet-Draft will expire on August 14, 2012.

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1.  Introduction

   The Zlib [RFC1950] and gzip [RFC1952] formats are widely used
   compression formats.  Zlib is a stream format, while glib adds header
   and trailer fields more appropriate for a file format.  They are used
   to compress a wide variety of material, from unstructured text to
   structured data to executable code.

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2.  The Application/Zlib Media Type

   The application/zlib media type describes a block of data that is
   compressed using Zlib [RFC1950] compression.  The data is a stream of
   bytes as described in RFC 1950.

2.1.  Regsistration Details

   Type name: application

   Subtype name: zlib

   Required parameters: none

   Optional parameters: none

   Encoding considerations: needs base64 or other encoding that allows
   arbitrary binary data

   Security considerations: See section [security] below

   Interoperability considerations: none

   Published specification: [RFC1950]

   Applications that use this media type: anywhere data size is an issue

   Additional information:

      Magic number(s): first byte is usually 0x78 but can also be 0x08,
      0x18, 0x28, 0x38, 0x48, 0x58, or 0x68.
      File extension(s): none
      Macintosh file type code(s): none

   Person and email address to contact for further information: see
   http://www.zlib.net/

   Intended usage: COMMON

   Restrictions on usage: none

   Author: John Levine

   Change controller: IETF

3.  The Application/Gzip Media Type

   The application/gzip media type describes a block of data that is
   compressed using gzip [RFC1952] compression.  The data is a stream of
   bytes as described in RFC 1952.

3.1.  Regsistration Details

   Type name: application

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   Subtype name: gzip

   Required parameters: none

   Optional parameters: none

   Encoding considerations: needs base64 or other encoding that allows
   arbitrary binary data

   Security considerations: See section [security] below

   Interoperability considerations: none

   Published specification: [RFC1952]

   Applications that use this media type: anywhere data size is an issue

   Additional information:

      Magic number(s): first two bytes are 0x1f, 0x8b.
      File extension(s): gz
      Macintosh file type code(s): none

   Person and email address to contact for further information: see
   http://www.gzip.net/

   Intended usage: COMMON

   Restrictions on usage: none

   Author: John Levine

   Change controller: IETF

4.  Security Considerations

   Zlib and gzip compression can be used to compress arbitrary binary
   data such as hostile executable code.  Also, data that purports to be
   in zlib or gzip format may not be, and fields that are supposed to be
   flags, lengths, or pointers, could contain anything.  Applications
   should treat any data with due scepticism.

5.  References

   [RFC1950]  Deutsch, L.P. and J-L. Gailly, "ZLIB Compressed Data
              Format Specification version 3.3", RFC 1950, May 1996.

   [RFC1951]  Deutsch, P., "DEFLATE Compressed Data Format Specification
              version 1.3", RFC 1951, May 1996.

   [RFC1952]  Deutsch, P., Gailly, J-L., Adler, M., Deutsch, L.P. and G.
              Randers-Pehrson, "GZIP file format specification version
              4.3", RFC 1952, May 1996.

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   [RFC4288]  Freed, N. and J. Klensin, "Media Type Specifications and
              Registration Procedures", BCP 13, RFC 4288, December 2005.

Author's Address

   John Levine
   Taughannock Networks
   PO Box 727
   Trumansburg, NY 14886
   
   Phone: +1 831 480 2300
   Email: standards@taugh.com

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