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Content-Digest header

From: Chris Newman <chrisn+@cmu.edu>
Date: Wed, 15 Nov 1995 14:47:36 -0500 (EST)
To: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
Cc: Chris Newman <chrisn+@cmu.edu>
Message-Id: <816464856.21313.0@nifty.andrew.cmu.edu>
I believe the proposal draft-demailly-cd-header-00 is extremely
counter-productive.

My concerns:

1) Creating a new mechanism to provide an existing service (Content-MD5)
would cause user agents to be more complex with no gain in functionality.

2) Allowing more than one digest algorithm is harmful to interoperability.

3) Content-MD5 is a widely deployed Draft Standard protocol.  It works well
in practice.  It is unlikely the IETF will permit an incompatible method for
doing the same thing to be standardized, and I will certainly encourage them
to oppose this proposal.

To address the complaints with Content-MD5:

1) You have to digest _something_ and it is important that that something is
well specified.  Thus canonical format discussions are absolutely necessary.
The canonical format for http is whatever data is sent over the wire
as the "body".

2) What's the big deal of converting between base64 and hex coding?  It's
a few lines of code, and is only an aesthetic consideration.

3) If MD5 is too computationally intensive for some situation, then there
probably shouldn't be any digest in that situation to get reasonable
performance.
-----
Chris Newman <chrisn+@cmu.edu>, http://www.contrib.andrew.cmu.edu/~nifty/
The worst thing about censorship is: [censored]
Received on Wednesday, 15 November 1995 11:57:39 EST

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