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   Re: [xml-dev] What is the difference between the XMLinfoset and Canonica

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XML Infoset:

The XML Information Set (or "Infoset") defines an abstract data set
whose purpose is to provide a consistent set of definitions for use in
other specifications that need to refer to the information in a
well-formed XML document. This information set is defined in terms of
"information items", which is an abstract description of a part of an
XML document that has specific properties. For example, specifications
refer to an "element information item" rather than an "element", and an
element information item has properties such as a namespace name,
attributes, parent, children, etc. See [1] for more...information.

Canonical XML:

XML documents can vary in physical representation based on syntactic
"options" that are allowed in XML. For example, attribute order is not
important, quotes can be single or double, etc. Canonical XML[2] defines
a method for generating a physical representation of an XML document -
called a "canonical form" - that accounts for these differences in
syntactic representation. If 2 XML documents have the same canonical
form, they are considered to be logically equivalent. 

For example, the generation of a digital signature over an XML document
is normally done over the canonical form of the XML document, and the
validation of the signature by the receiver is also done over the
canonical form. Since various processors may introduce incidental
changes into an XML document over the course of its processing, using
the canonical version of an XML document in this case helps ensure that
the signature processing is not affected by these incidental changes.

Kind Regards,
Joe Chiusano
Booz | Allen | Hamilton

[1] http://www.w3.org/TR/xml-infoset/
[2] http://www.w3.org/TR/xml-c14n

Jon Steeves wrote:
> Hello:
>   Can anyone give a brief explanation of the difference between the XMLinfoset and Canonical xml?
> I.e., what their differing purposes are and how they differ as specs.  This would be much appreciated.
> Cheers
> Jon Steeves
> pmc-sierra.com
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tel;work:(703) 902-6923
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adr:;;8283 Greensboro Drive;McLean;VA;22012;
title:Senior Consultant
fn:Joseph M. Chiusano


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