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Instance Digests in HTTP (RFC3230)

IP.com Disclosure Number: IPCOM000006599D
Original Publication Date: 2002-Jan-01
Included in the Prior Art Database: 2002-Jan-16
Document File: 14 page(s) / 27K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Mogul: AUTHOR [+2]

Abstract

HTTP/1.1 defines a Content-MD5 header that allows a server to include a digest of the response body. However, this is specifically defined to cover the body of the actual message, not the contents of the full file (which might be quite different, if the response is a Content- Range, or uses a delta encoding). Also, the Content-MD5 is limited to one specific digest algorithm; other algorithms, such as SHA-1 (Secure Hash Standard), may be more appropriate in some circumstances. Finally, HTTP/1.1 provides no explicit mechanism by which a client may request a digest. This document proposes HTTP extensions that solve these problems.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 13% of the total text.

Network Working Group                                           J. Mogul

Request for Comments: 3230                                    Compaq WRL

Category: Standards Track                                    A. Van Hoff

                                                                 Marimba

                                                            January 2002

                        Instance Digests in HTTP

Status of this Memo

   This document specifies an Internet standards track protocol for the

   Internet community, and requests discussion and suggestions for

   improvements.  Please refer to the current edition of the "Internet

   Official Protocol Standards" (STD 1) for the standardization state

   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   HTTP/1.1 defines a Content-MD5 header that allows a server to include

   a digest of the response body.  However, this is specifically defined

   to cover the body of the actual message, not the contents of the full

   file (which might be quite different, if the response is a Content-

   Range, or uses a delta encoding).  Also, the Content-MD5 is limited

   to one specific digest algorithm; other algorithms, such as SHA-1

   (Secure Hash Standard), may be more appropriate in some

   circumstances.  Finally, HTTP/1.1 provides no explicit mechanism by

   which a client may request a digest.  This document proposes HTTP

   extensions that solve these problems.

Table of Contents

   1 Introduction....................................................  2

        1.1 Other limitations of HTTP/1.1............................  3

   2 Goals...........................................................  4

   3 Terminology.....................................................  5

   4 Specification...................................................  6

        4.1 Protocol parameter specifications........................  6

             4.1.1 Digest algorithms.................................  6

        4.2 Instance digests.........................................  7

        4.3 Header specifications....................................  8

             4.3.1 Want-Digest.......................................  8

             4.3.2 Digest............................................  9

   5 Negotiation of Content-MD5......................................  9

Mogul, et. al.              Standards Track                     [Page 1]

RFC 3230                Instance Digests in HTTP            January 2002

   6 IANA Considerations............................................. 10

   7 Security Considerations......................................... 10

   8 Acknowledgements................................................ 10

   9 References...................................................... 10

   10 Authors' Addresses............................................. 12

   11 Full Copyright Statement....................................... 13

1 Introduction

   Although HTTP is typically layered over a reliable transport

   protocol, such as TCP, this does not guarantee reliable transport of

   information from sender to receiver.  Various problems, including

   undetected transmission errors, programming errors, corruption of

   stored data, and malicious intervention can cause errors in the

   transmitted information.

   A common approach to the problem of data integrity in a network

   protocol or distributed syste...