Merge branch 'master' of ssh://git.ikiwiki.info/srv/git/ikiwiki.info

doc/todo/finer_control_over___60__object___47____62__s.mdwn

@@ -27,13 +27,43 @@ For Ikiwiki, it may be nice to be able to restrict [URI's][URI] (as required by
 
 [[wishlist]]
 
-> SVG can contain embedded javascript. The spec that you link to contains
+> SVG can contain embedded javascript.
+
+>> Indeed.
+
+>> So, a more general tool (`XML::Scrubber`?) will be necessary to
+>> refine both [XHTML][] and SVG.
+
+>> … And to leave [MathML][] as is (?.)
+
+>> — [[Ivan_Shmakov]], 2010-03-12Z.
+
+> The spec that you link to contains
 > examples of objects that contain python scripts, Microsoft OLE 
 > objects, and Java. And then there's flash. I don't think ikiwiki can
 > assume all the possibilities are handled securely, particularly WRT XSS
 > attacks.
 > --[[Joey]]
 
+>> I've scanned over all the `object` examples in the specification and
+>> all of those that hold references to code (as opposed to data) have a
+>> distinguishing `classid` attribute.
+
+>> While I won't assert that it's impossible to reference code with
+>> `data` (and, thanks to `text/xhtml+xml` and `image/svg+xml`, it is
+>> *not* impossible), throwing away any of the “insecure”
+>> attributes listed above together with limiting the possible URI's
+>> (i. e., only *local* and certain `data:` ones for `data` and
+>> `usemap`) should make `object` almost as harmless as, say, `img`.
+
+>> (Though it certainly won't solve the [[SVG_problem|/todo/SVG]] being
+>> restricted in such a way.)
+
+>> Of the remaining issues I could only think of recursive
+>> `object` — the one that references its container document.
+
+>> — [[Ivan_Shmakov]], 2010-03-12Z.
+
 ## See also
 
 * [Objects, Images, and Applets in HTML documents][objects-html]
@@ -43,6 +73,8 @@ For Ikiwiki, it may be nice to be able to restrict [URI's][URI] (as required by
 * [Uniform Resource Identifier — the free encyclopedia][URI]
 
 [HTML::Scrubber]: http://search.cpan.org/~podmaster/HTML-Scrubber-0.08/Scrubber.pm
+[MathML]: http://en.wikipedia.org/wiki/MathML
 [objects-html]: http://www.w3.org/TR/1999/REC-html401-19991224/struct/objects.html
 [RFC 2397]: http://tools.ietf.org/html/rfc2397
 [URI]: http://en.wikipedia.org/wiki/Uniform_Resource_Identifier
+[XHTML]: http://en.wikipedia.org/wiki/XHTML