From: Laurent Demailly <dl@hplyot.obspm.fr>
Date: Wed, 4 Oct 95 15:39:36 PDT
To: Alan Barrett <barrett@iafrica.com>
Subject: Re: New version of my privacy enhanced www proxy is out
In-Reply-To: <9510042024.AA16962@hplyot.obspm.fr>
Message-ID: <9510042239.AA17348@hplyot.obspm.fr>
MIME-Version: 1.0
Content-Type: text/plain


(BCCed to aproxy list, to avoid followup troubles)
Alan Barrett writes:
 > > The proxy now issue  "Content-Checksums: md5=xxxxxx"
Btw i typoed, I use "Content-Checksum: md5=<hexa/ascii-output>"
like in "Content-Checksum: md5=0246be185424cc79b61f4a55b73362c1"
like does the "md5" and md5sum (pgp's contrib dir) programs
 > > headers for its stuff, I 'invented' that  syntax, any www guru to tell
 > > me if it already exists under another form ? (i checked the
 > > http docs at w3.org, found nothing)
 > 
 > RFC 1544 specifies the Content-MD5 header field for use with 
 > MIME-conformant messages.  It looks like this:
 > 
 >                Content-MD5:  Q2hlY2sgSW50ZWdyaXR5IQ==
Thanks very much for pointing out,

I don't like the fact they somehow hard wired the checksum/digest
algorithm in the keyword name, it is imo a bad idea, when you will want to
use another algorithm, also the rfc state that the checksum applies to
"canonical" form, the one I want applies to the "Content-Length" bytes
you read, whatever they are (no interpretation), and I don't like the
use of base64 which is not nice if you want to check with existing
md5,md5sum programs what you get.

I stepped meanwhile on a draft on authorization scheme using digest, 
which might be interesting... when implemented client side... more on
this later (ref:
http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-digest-aa-01.txt
see also
http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-mda-00.txt
for a "mediated digest" authentification/security scheme)

dl
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