- From: Yves Lafon <ylafon@w3.org>
- Date: Tue, 30 Jun 2009 04:37:10 -0400 (EDT)
- To: Mark Nottingham <mnot@mnot.net>
- cc: HTTP Working Group <ietf-http-wg@w3.org>, Larry Masinter <LMM@acm.org>
On Mon, 29 Jun 2009, Mark Nottingham wrote:
> a) C-MD5 applies to the bytes in the entity-body (as above), and therefore we
> need to specify what a cache does with it when it combines partial responses
> (throw it away?).
>
> b) C-MD5 applies to the *full* response body, avoiding the combination
> issues, and allowing clients to do a MIC of the full response (assuming they
> have it), but removing the ability to do a MIC on a partial response on its
> own.
>
> Anybody aware of C-MD5 being used with partial responses in the wild (I'm
> looking at you, Adobe)?
A while back, I implemented option a) as it seemed to be the most logical
interpretation of the spec.
HEAD /Distrib/jigsaw_2.2.6.zip HTTP/1.1
Host: jigsaw.w3.org
HTTP/1.1 200 OK
Content-Length: 9331520
Content-Md5: fBhlh9ttr14YAqe45Yi+xg==
------
GET /Distrib/jigsaw_2.2.6.zip HTTP/1.1
Host: jigsaw.w3.org
Range: bytes=0-1
HTTP/1.1 206 Partial Content
Content-Length: 2
Content-Md5: 1xvdIsi7k7jSh9zm9GrtJQ==
Content-Range: bytes 0-1/9331520
Caches should "throw away" the md5 (after verification of the partial body
received, and it is up to the cache to recompute the md5 sum of the bytes
served.
--
Baroula que barouleras, au tiéu toujou t'entourneras.
~~Yves
Received on Tuesday, 30 June 2009 08:37:20 UTC