Internet Engineering Task Force (IETF) A. Bryan
Request for Comments: 5843 April 2010
Category: Informational
ISSN: 2070-1721

Additional Hash Algorithms for HTTP Instance Digests

Abstract

   The IANA registry named "Hypertext Transfer Protocol (HTTP) Digest
   Algorithm Values" defines values for digest algorithms used by
   Instance Digests in HTTP.  Instance Digests in HTTP provide a digest,
   also known as a checksum or hash, of an entire representation of the
   current state of a resource.  This document adds new values to the
   registry and updates previous values.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc5843.

Copyright Notice

   Copyright (c) 2010 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
   (http://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
   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.

   1. Introduction ....................................................2
      1.1. Example ....................................................2
   2. IANA Considerations .............................................2
      2.1. Previous Registrations Updated .............................2
      2.2. New Registrations ..........................................3
   3. Security Considerations .........................................3
   4. Changes Compared to RFC 3230 ....................................3
   5. Normative References ............................................4
   Appendix A. Acknowledgements and Contributors ......................5

1. Introduction

   The IANA registry named "Hypertext Transfer Protocol (HTTP) Digest
   Algorithm Values" defines values for digest algorithms used by
   Instance Digests in HTTP.

   Note: This is unrelated to HTTP Digest Authentication.  Instance
   Digests in HTTP provide a digest, also known as a checksum or hash,
   of an entire representation of the current state of a resource.

   The registry was created by [RFC3230] in 2002.  This document adds
   new values to the registry and updates previous values that had
   redundant or outdated references.

1.1. Example

   Example of Instance Digest for SHA-256:

   Digest: SHA-256=MWVkMWQxYTRiMzk5MDQ0MzI3NGU5NDEyZTk5OWY1ZGFmNzgyZTJlO
   DYzYjRjYzFhOTlmNTQwYzI2M2QwM2U2MQ==

2. IANA Considerations

   This document makes use of the IANA registry named "Hypertext
   Transfer Protocol (HTTP) Digest Algorithm Values" specified in
   [RFC3230].

2.1. Previous Registrations Updated

   Accordingly, IANA has updated the following registrations:

      Digest Algorithm: MD5

      Description: The MD5 algorithm, as specified in [RFC1321].  The
      output of this algorithm is encoded using the base64 encoding
      [RFC4648].

      Reference: [RFC1321], [RFC4648], this document.

      Digest Algorithm: SHA

      Description: The SHA-1 algorithm [FIPS-180-3].  The output of this
      algorithm is encoded using the base64 encoding [RFC4648].

      Reference: [FIPS-180-3], [RFC4648], this document.

2.2. New Registrations

   Accordingly, IANA has made the following registrations:

      Digest Algorithm: SHA-256

      Description: The SHA-256 algorithm [FIPS-180-3].  The output of
      this algorithm is encoded using the base64 encoding [RFC4648].

      Reference: [FIPS-180-3], [RFC4648], this document.

      Digest Algorithm: SHA-512

      Description: The SHA-512 algorithm [FIPS-180-3].  The output of
      this algorithm is encoded using the base64 encoding [RFC4648].

      Reference: [FIPS-180-3], [RFC4648], this document.

3. Security Considerations

Same as [RFC3230].

4. Changes Compared to RFC 3230

   The reference for base64 encoding has been updated for both MD5 and
   SHA.

   The reference for SHA has been updated.

   The SHA-256 and SHA-512 algorithms have been added to the registry.

   All other previous values to the registry are still valid.

5. Normative References

   [FIPS-180-3]  National Institute of Standards and Technology (NIST),
                 "Secure Hash Standard (SHS)", FIPS PUB 180-3,
                 October 2008.

   [RFC1321]     Rivest, R., "The MD5 Message-Digest Algorithm",
                 RFC 1321, April 1992.

   [RFC3230]     Mogul, J. and A. Van Hoff, "Instance Digests in HTTP",
                 RFC 3230, January 2002.

   [RFC4648]     Josefsson, S., "The Base16, Base32, and Base64 Data
                 Encodings", RFC 4648, October 2006.

Appendix A. Acknowledgements and Contributors

   Thanks to Mark Nottingham, Eran Hammer-Lahav, Nils Maier, Lisa
   Dusseault, Alfred Hoenes, Pasi Eronen, Gonzalo Camarillo, Radia
   Perlman, and Jeffrey Mogul.

Author's Address

   Anthony Bryan
   Pompano Beach, FL
   USA

   EMail: anthonybryan@gmail.com
   URI:   http://www.metalinker.org