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Re: Peter's RE: Irvine Minutes and ost-FTF syntax proposal

From: John Boyer <jboyer@uwi.com>
Date: Thu, 9 Sep 1999 16:02:43 -0700
To: "Peter Norman" <pnorman@mediaone.net>, <w3c-ietf-xmldsig@w3.org>
Message-ID: <NDBBLAOMJKOFPMBCHJOIEECDCBAA.jboyer@uwi.com>
<Peter> All I'd like to add to this is that the processing instructions are
merely labels and don't have any direct semantic effect. While it would be
reasonable to start at a start and end at an end, with Xptr you could start
three elements past an end and end two elements before a start if you were
so perverse. While we've been saying 'remove' about dsig target PIs, we may
want to be neutral between 'remove' and 'ignore for hashing'.
</Peter>

<John>
'Ignore for hashing' *is the same as* 'remove' with respect to my comments
in the letter to Don and the group.
</John>

<Peter> I did in fact intend that dsig target PIs NOT be substantive. They
should be ignored for signature purposes and carry no semantics other than
location. Anything within a dsig target PI (from <? to ?> inclusive) should
be unsigned by definition.
</Peter>

<John>
Can you please comment on how to achieve document closure by this method
(please note my comments in the letter to Don and the group)?  In
particular, how can this method prevent arbitrary content from being added
between the signed regions?  Further, can you explain how this method would
sign parts of externally stored resources, esp. when the signer does not
have write access to those resources to put the unsigned PIs in place?

A single properly used XPointer solves all of these problems.

Finally, Don's email seemed to make use of XPointer to indicate the target
PIs anyway.  Is this your view as well?  If so, then this discussion is not
about whether to support XPointer but rather how to apply it.

Either way, given the problems I've pointed out, would you agree that we
should not use target PIs, target elements, or dsig:exclude attributes to
solve the problems related to partial document?

John Boyer
Software Development Manager
UWI.Com -- The Internet Forms Company
</John>
Received on Thursday, 9 September 1999 19:04:39 GMT

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