W3C home > Mailing lists > Public > w3c-ietf-xmldsig@w3.org > July to September 2001

RE: initial Exclusive Canonicalization draft

From: John Boyer <JBoyer@PureEdge.com>
Date: Thu, 12 Jul 2001 09:48:00 -0700
Message-ID: <7874BFCCD289A645B5CE3935769F0B5219632E@tigger.PureEdge.com>
To: <vdv@dyomedea.com>, "merlin" <merlin@baltimore.ie>
Cc: "Donald E. Eastlake 3rd" <dee3@torque.pothole.com>, <w3c-ietf-xmldsig@w3.org>, <lde008@dma.isg.mot.com>

Hi Eric,

Could you explain a bit more clearly what you mean by "specify which
namespaces prefixes cannot be rewritten"?  An example to show the
behavior you would expect of such a feature would be helpful.

It is difficult to tell without more information why the regular XML
c14n does work in the following:

"If I wanted to canonicalize a XSLT template or a W3C XML Schema element
definition I would certainly like to preserve all the prefixes."

John Boyer
Senior Product Architect, Software Development
Internet Commerce System (ICS) Team
PureEdge Solutions Inc. 
Trusted Digital Relationships
v: 250-708-8047  f: 250-708-8010
1-888-517-2675   http://www.PureEdge.com <http://www.pureedge.com/>  	

-----Original Message-----
From: Eric van der Vlist [mailto:vdv@dyomedea.com]
Sent: Thursday, July 12, 2001 6:37 AM
To: merlin
Cc: Donald E. Eastlake 3rd; w3c-ietf-xmldsig@w3.org;
Subject: Re: initial Exclusive Canonicalization draft

merlin wrote:
> Hi Eric,
> r/vdv@dyomedea.com/2001.07.12/13:59:31
> >I find the idea of UnsuppressedNamespacePrefixList [1] very
> >and I wonder if a "DoNotRewriteNamespacePrefixList" that would
> >which namespaces prefixes cannot be rewritten (or a
> >"MayBeRewrittenNamespacePrefixList" that would specify which of them
> >be rewritten) couldn't solve the issue of prefix rewriting in a very
> >consensual way.
> Does rewriting anything other than all prefixes actually provide
> any benefit?
> I understand that normalizing namespace prefixes may be useful to
> applications that do not preserve this information. However, if
> we are not to normalize certain prefixes then that implies that
> the relevant application will also preserve those prefixes, which
> implies that it could preserve all prefixes?
> I presume that you have a use in mind; can you elaborate?

I was proposing this by analogy with UnsuppressedNamespacePrefixList...

If I wanted to canonicalize a XSLT template or a W3C XML Schema element
definition I would certainly like to preserve all the prefixes.

A common class of applications that will likely be using QNames are all
the applications using XPointer expressions.

The latest XPointer LC offers a way to define the namespaces within the
XPointer expression itself [1], though and these applications should now
be able to deal with NS prefixes rewriting.

I am not a great supporter of using QNames as values and I was more
concerned by finding a way to (optionally) include prefix rewriting in
the canonicalization method than by the granularity of the feature and,
you're right, a boolean parameter (RewritePrefixes or
DontRewritePrefixes) may be a better way to achieve it.

[1] http://www.w3.org/TR/2001/WD-xptr-20010108/#ns-context

> Merlin
> Baltimore Technologies plc will not be liable for direct,  special,
> or consequential  damages  arising  from  alteration of  the contents
of this
> message by a third party or as a result of any virus being passed on.
> In addition, certain Marketing collateral may be added from time to
time to
> promote Baltimore Technologies products, services, Global e-Security
> appearance at trade shows and conferences.
> This footnote confirms that this email message has been swept by
> Baltimore MIMEsweeper for Content Security threats, including
> computer viruses.
>    http://www.baltimore.com

See you at XTech in San Diego.
Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
http://xsltunit.org      http://4xt.org           http://examplotron.org
Received on Thursday, 12 July 2001 12:48:32 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:21:36 UTC