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RE: c14n

From: Martin J. Duerst <duerst@w3.org>
Date: Fri, 26 May 2000 15:06:12 +0900
Message-Id: <>
To: "John Boyer" <jboyer@PureEdge.com>, "Alex Milowski" <alex@milowski.com>
Cc: "\"IETF/W3C XML-DSig WG\"" <w3c-ietf-xmldsig@w3.org>
At 00/05/23 10:33 -0700, John Boyer wrote:

> > 1) Eliminate character model normalization. XML 1.0 is based on UCS.  An
> > application should not change the UCS code point values used to represent
> > characters.  Although differing UCS code point sequences may result in the
> > same character visually, the knowledge of this equivalence resides outside
> > of the XML 1.0 specification.  Further, those who actually have the
> > are likely to (and should) normalize characters during document creation.
>I think this is fine.

This is not exactly fine. First, for XML, processors may or may not
take into account equivalences, and may change UCS code point values.
Please check 'match' in XML 1.0.

Second, while the i18n WG/IG agrees that character normalization
should not be part of XML canonicalization, there are contexts
where you may want to do both, and therefore the topic of
character normalization should explicitly be discussed in
the XML c14n document.

Third, in its use in XML signatures, XML c14n should not be
used directly in combination with character normalization
as a single transform, but character normalization should be
checked (not actually done) as a separate transform. Please
see the I18N WG/IG last call comments for this.

Regards,  Martin.
Received on Friday, 26 May 2000 02:23:05 UTC

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