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Protocol Action: The Content-MD5 Header Field to Draft Standard

1995-07-08 12:17:49

The IESG has approved the Internet-Draft "The Content-MD5 Header Field"
<RFC1544> as a Draft Standard. This document is the product of the
Internet Message Extensions Working Group. The IESG contact persons are
John Klensin and Harald Alvestrand.

Technical Summary

This protocol defines a mechanism for computing an integrity check on a
MIME body part and then provides a header for recording that integrity
check in the message.

Working Group Summary

RFC 1544 was published as a Proposed Standard in November 1993 with
input from the then RFC822 Extensions WG (822ext). The protocol has
been implemented, is deployed and in use, and no significant problems
have been found with the protocol definition in RFC 1544.

There are four known independent interoperating implementations of this
protocol. They are:

1. mpack/munpack, by John Gardiner Meyers, both generates and
   verifies the header

2. MH 6.8.3, both generates and verifies the header

3. PMDF (as-yet unreleased), by Innosoft, both generates and verifies
   the header

4. dtmail, by Sun, generates the header

Marshall Rose, the author of RFC 1544, reports that he has not received
any comments on the document.

Protocol Quality

The protocol was reviewed for IESG by John Klensin, Applications Area
Director. The protocol is in active use and there are, as noted above,
at least four implementations which have been shown to interoperate.


Since RFC1544 was published, a minor grammatical problem in the text
was noted by one person:

   not been modified during transport. Message relays and gateways are
   expressly forbidden to alter its processing based on the presence of
   the Content-MD5 field. However, a message gateway is allowed to

the word "its" should instead be "their".

In approving this document as a Draft Standard, IESG concluded that
the RFC should be reissued with the following editorial/clarifying

(i) In the first line of section 2, change "only by" to "by only".

(ii) In the third paragraph of section 2, change "canonical form of
the data." to "canonical form of the MIME body part.  The MIME body
part definition appears in the MIME definition [1]."

(iii) In section 3, change "forbidden to alter its" to forbidden to
alter their".

(iv) Add to the end of section 5 "The IESG made clarifying and
editorial changes to the earlier RFC 1544 in advancing this document
to Draft Standard."