[x3d-public] [communications] X3D DOCTYPE problem

[vmarchetti at kshell.com]

As observed at 10:20 PM EDT on 12 Sept 2020

A HTTP request to https://www.web3d.org/specifications/x3d-3.3.dtd made with the curl tool (on Mac OS) returns the 142k DTD file, appears well formed

The request to the http (unencrypted, discouraged by modern browsers) http://www.web3d.org/specifications/x3d-3.3.dtd returns a redirect HTTP response, with headers:

HTTP/1.1 302 Found
Date: Sun, 13 Sep 2020 02:15:33 GMT
Server: Apache
X-Content-Type-Options: nosniff
Location: https://www.web3d.org/specifications/x3d-3.3.dtd
Cache-Control: max-age=1209600
Expires: Sun, 27 Sep 2020 02:15:33 GMT
Content-Length: 232
Content-Type: text/html; charset=iso-8859-1


and the body of the HTTP response is an HTML-markup version of this information, so not well formed DTD.

It appears that some of the validation tools will follow the redirect and some will not.

I do not know if the server configuration has been changed recently to redirect requests to URLS  in http://www.web3d.org/specifications/* space.

Request for our webpages i.e. http://www.web3d.org/ have been redirected for some time.

Solutions to this problem would be

-- allow server to directly server requests to http://www.web3d.org/specifications/* without redirection
-- update or configure tools to follow HTTP 302 redirections

Vince Marchetti

> On Sep 12, 2020, at 7:55 PM, Don Brutzman <brutzman at nps.edu> wrote:
> 
> We noticed an emergent problem with X3D Validator about a week ago and, with difficulty, have been trying to sleuth what the root cause might be.
> 
> After multiple diagnostic efforts, we now think that the problem is on the web3d.org server, there is some issue within the DTD files themselves.  Unfortunately there is also a problem with my account which currently prevents troubleshooting further and (hopefully) fixing it.
> 
> This problem has blocked proper DTD validation, which might in turn block validation of numerous tools loading/validating X3D models.  Have confirmed that some tools work (probably due to prior caching) and other tools fail. Example failure output:
> 
>> check well-formedness
>> http://www.web3d.org/specifications/x3d-3.3.dtd:1:3: The markup declarations contained or pointed to by the document type declaration must be well-formed.
>> Could not validate document C:\x3d-code\www.web3d.org\x3d\content\examples\X3dForWebAuthors\HelloWorld.x3d: org.xml.sax.SAXParseExceptionpublicId: ISO//Web3D//DTD X3D 3.3//EN; systemId: http://www.web3d.org/specifications/x3d-3.3.dtd; lineNumber: 1; columnNumber: 3; The markup declarations contained or pointed to by the document type declaration must be well-formed.
>> C:\x3d-code\www.web3d.org\x3d\content\examples\X3dForWebAuthors\HelloWorld.x3d is not a valid XML document
> 
> Meanwhile XML Spy can validate the same model successfully.  It is both exceptionally strict and also added native X3D support a few months back.  So this approach confirms that X3D models we are testing remain unchanged and correct.
> 
> Web3D Communications Team and webmaster have been notified about the access problem preventing further troubleshooting.
> 
> The DOCTYPE problem does not appear to prevent successful X_ITE and X3DOM display of X3D models.
> 
> * https://x3dgraphics.com/examples//X3dForWebAuthors/Chapter02GeometryPrimitives/BoxExampleX_ITE.html
> * https://x3dgraphics.com/examples//X3dForWebAuthors/Chapter02GeometryPrimitives/BoxExampleX3dom.xhtml
> 
> Once this is also sorted out, will post regarding resumption of capability.  Apologies for any difficulties this problem causes tool developers and scene modelers.
> 
> all the best, Don
> -- 
> Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
> Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
> X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman
> 
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