RE: AW: Call for Implementation: Canonical XML Becomes a W3C Candidate Recommendation

Hi Kent,

It is easy enough to change the examples, but the purpose of the examples is
to show how XML can change as the result of c14n.  If one is using a
validating parser, one is expected to be able to modify the examples to
account for this.  It's really easy; you put DTD declarations into the
document until it validates, and all of your DTD declarations are removed,
so the canonical form is unchanged.

So, clearly I am most interested in your troubles with the non-validating
version of Xerces.  It certainly appears to me that Xerces does not fully
comply with XML 1.0 if it does not read attribute types and provide them to
the application for use.  It's DOM call may decide not to work, but even if
you have to implement id searching yourself, the attribute type should at
least be available for you to do this.  If not, IBM needs to do a patch for
you.

It would actually be better to get tools out there that can process the
examples as they are than it would be to let this go and have
non-interoperable signatures because even the major vendors don't follow the
spec closely enough for the ever scrutinous sha-1 hash.

John Boyer
Development Team Leader,
Distributed Processing and XML
PureEdge Solutions Inc.
Creating Binding E-Commerce
v: 250-479-8334, ext. 143  f: 250-479-3772
1-888-517-2675   http://www.PureEdge.com <http://www.pureedge.com/>


-----Original Message-----
From: w3c-ietf-xmldsig-request@w3.org
[mailto:w3c-ietf-xmldsig-request@w3.org]On Behalf Of TAMURA Kent
Sent: Friday, November 17, 2000 12:39 AM
To: w3c-ietf-xmldsig@w3.org
Subject: Re: AW: Call for Implementation: Canonical XML Becomes a W3C
Candidate Recommendation



In message "RE: AW: Call for Implementation: Canonical XML Becomes a W3C
Candidate   Recommendation"
    on 00/11/10, "John Boyer" <jboyer@PureEdge.com> writes:
> As well, your assertion that the Xerces DOM parser cannot select by id
> unless using validation seems, on the surface, to contradict IBM's
> interoperability report since they are most certainly using Xerces and yet
> were able to complete example 3.7.
>
> Moreover, if the id() function is something you have to implement, it is
not
> actually very hard to implement as long as 1) the parser correctly types
the
> id attribute when not validating, and 2) it is easy to hook your resulting
> id() function into the Xpath implementation that evaluates the expression
> given in example 3.7.  Are you saying that one of these two things isn't
> working.

The Document.getElementsById() method of Xerces-J's DOM
implementation works only with the validating parser.  while I
tested the example 3.7, the parser output many validation
errors.  Fortunately, the parser does not stop parsing and
validation on a validation error.

In general, a validating XML processor MAY stop parsing on a
validation error, and a non-validating XML processor need not
process attribute types.  We would not get correct results of
example 3.4 and 3.7 with such XML processors.  I think example
3.4 and 3.7 have to be modified so that they become valid
documents.

--
TAMURA Kent @ Tokyo Research Laboratory, IBM

Received on Friday, 17 November 2000 16:52:51 UTC