Oh I wasn't try to divert stuff with you dude .. I definitely know you well enough for that.
Neither am I at all proposing default behavior - I think the only "fix" is to have an option to serialize without losing anything. I don't see any issue with that. On the specific issue- I'm looking for clarification .. I've started a thread with James Clark (who wrote the XPath spec and helped with the NS spec and knows a lot of this stuff much better than I ever will) to get it clarified. Will report back shortly (and I'm usually wrong with him so I'm expecting there's some flaw in my logic / reading of the spec). Sanjiva. On Wed, Nov 23, 2011 at 12:52 AM, Andreas Veithen <[email protected] > wrote: > Sanjiva, > > I think that you know me well enough by now to know that neither > authority arguments nor diversions work with me. You made an assertion > and I challenge you to prove it. You are not going to get away that > easily ;-) > > Note that I think that removing a redundant namespace declaration may > indeed cause problems with canonicalization, but only if several > conditions are met. I would like to understand when this occurs and if > the case that Charith encountered is an example of this or if the > issue is caused by a broken client, a broken back-end service or an > incorrect security policy. > > To answer your question: yes, removing redundant namespace > declarations has been the default behavior in Axiom for a long time > (even before I started to work on Axiom) and it should stay the > default behavior. There are a couple of reasons for that. I will > explain them to you once you come up with a correct argument > supporting your point of view. We can then confront these arguments to > see what is the correct solution for the problem. > > Andreas > > On Tue, Nov 22, 2011 at 18:21, Sanjiva Weerawarana > <[email protected]> wrote: > > 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/ > > > > --------------------------------------------------------------------- > 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/
