Andreas independent of the C14N aspect, with Axiom if you read a doc and write it back out the XML will be different. Is that what we want the default behavior to be?
The spec has a convoluted set of guidelines on when its ok to drop stuff .. I will try to give you a concrete example but I think the above question is far simpler. Sanjiva. On Tue, Nov 22, 2011 at 6:36 PM, Andreas Veithen <[email protected]>wrote: > Well, the problem is that that specification actually contradicts what > you are saying. You can find the relevant quote in section 2.1 "Data > Model": > > "An element E has namespace nodes that represent its namespace > declarations as well as any namespace declarations made by its > ancestors that have not been overridden in E's declarations, the > default namespace if it is non-empty, and the declaration of the > prefix xml." > > Removing a redundant namespace declaration therefore doesn't change > the data model because that declaration is "restored" by virtue of the > second part of that definition. Therefore the output of the > canonicalization (and hence the signature) doesn't change. > > Andreas > > Note: the superfluous namespace declarations implied by this > definition are eliminated by the following rule specified in section > 2.3 "Processing Model": > > "A namespace node N is ignored if the nearest ancestor element of the > node's parent element that is in the node-set has a namespace node in > the node-set with the same local name and value as N. Otherwise, > process the namespace node N in the same way as an attribute node, > except assign the local name xmlns to the default namespace node if it > exists (in XPath, the default namespace node has an empty URI and > local name)." > > On Tue, Nov 22, 2011 at 13:31, Sanjiva Weerawarana > <[email protected]> wrote: > > http://www.w3.org/TR/xml-c14n > > > > On Tue, Nov 22, 2011 at 5:59 PM, Sanjiva Weerawarana < > [email protected]> > > wrote: > >> > >> Please look at the C14N spec. > >> > >> On Tue, Nov 22, 2011 at 4:00 PM, Andreas Veithen > >> <[email protected]> wrote: > >>> > >>> Sanjiva, > >>> > >>> Can you substantiate these claims by references to the spec or > >>> concrete examples? > >>> > >>> Andreas > >>> > >>> On Tue, Nov 22, 2011 at 03:51, Sanjiva Weerawarana > >>> <[email protected]> wrote: > >>> > Thanks for the clear writeup Andreas. > >>> > On Tue, Nov 22, 2011 at 12:41 AM, Andreas Veithen > >>> > <[email protected]> wrote: > >>> >> > >>> >> removal of redundant namespace declarations? I don't know the C14N > >>> >> specs well enough to answer that question, but I've seen that these > >>> >> specs make provisions to preserve the namespace context of the > element > >>> >> and also define an algorithm to remove redundant namespace > >>> >> declarations (search for "superfluous" or "unnecessary" namespace > >>> >> declarations through the specs). > >>> > > >>> > Simple answer is that yes the spec is sensitive to any nodes being > >>> > removed, > >>> > including seemingly redundant namespace nodes. As Alek noted, with > the > >>> > advent of XPath, its now possible for a namespace declaration that > >>> > looks > >>> > redundant to an XML parser to actually be required. However this case > >>> > is > >>> > simpler- the element is signed and removing the node breaks the > >>> > signature. > >>> > I think we need to have a way to say "don't mess with the XML > >>> > serialization > >>> > AT ALL" .. that is what we want in the case of Synapse is not just an > >>> > infoset preserving serialization but rather the EXACT serialization. > >>> > Sanjiva. > >>> > -- > >>> > Sanjiva Weerawarana, Ph.D. > >>> > Founder, Director & Chief Scientist; Lanka Software Foundation; > >>> > http://www.opensource.lk/ > >>> > Founder, Chairman & CEO; WSO2; http://wso2.com/ > >>> > Founder & Director; Thinkcube Systems; http://www.thinkcube.com/ > >>> > Member; Apache Software Foundation; http://www.apache.org/ > >>> > Visiting Lecturer; University of Moratuwa; http://www.cse.mrt.ac.lk/ > >>> > > >>> > Blog: http://sanjiva.weerawarana.org/ > >>> > > >>> > >>> --------------------------------------------------------------------- > >>> To unsubscribe, e-mail: [email protected] > >>> For additional commands, e-mail: [email protected] > >>> > >> > >> > >> > >> -- > >> Sanjiva Weerawarana, Ph.D. > >> Founder, Director & Chief Scientist; Lanka Software Foundation; > >> http://www.opensource.lk/ > >> Founder, Chairman & CEO; WSO2; http://wso2.com/ > >> Founder & Director; Thinkcube Systems; http://www.thinkcube.com/ > >> Member; Apache Software Foundation; http://www.apache.org/ > >> Visiting Lecturer; University of Moratuwa; http://www.cse.mrt.ac.lk/ > >> > >> Blog: http://sanjiva.weerawarana.org/ > > > > > > > > -- > > Sanjiva Weerawarana, Ph.D. > > Founder, Director & Chief Scientist; Lanka Software Foundation; > > http://www.opensource.lk/ > > Founder, Chairman & CEO; WSO2; http://wso2.com/ > > Founder & Director; Thinkcube Systems; http://www.thinkcube.com/ > > Member; Apache Software Foundation; http://www.apache.org/ > > Visiting Lecturer; University of Moratuwa; http://www.cse.mrt.ac.lk/ > > > > Blog: http://sanjiva.weerawarana.org/ > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > -- Sanjiva Weerawarana, Ph.D. Founder, Director & Chief Scientist; Lanka Software Foundation; http://www.opensource.lk/ Founder, Chairman & CEO; WSO2; http://wso2.com/ Founder & Director; Thinkcube Systems; http://www.thinkcube.com/ Member; Apache Software Foundation; http://www.apache.org/ Visiting Lecturer; University of Moratuwa; http://www.cse.mrt.ac.lk/ Blog: http://sanjiva.weerawarana.org/
