On Tue, Jan 11, 2011 at 3:33 PM, Joshua Tacoma <joshua.tacoma@gmail.com> wrote:
On 11 January 2011 15:41, Radomir Dopieralski <moinmoin@sheep.art.pl> wrote:
> On Tue, Jan 11, 2011 at 9:36 PM, Joshua Tacoma <joshua.tacoma@gmail.com> wrote:
> > - Are the security issues so obviously and deeply hairy that no one in their
> > right mind would do such a thing?
> Yes, there are security issues. Basically, the javascript on the page
> has access to the cookie (and thus the session) of the user who is
> browsing the page, and can act in that user's name on the wiki, doing
> anything the user can do.

Thanks, I was wondering about that... some ways to fix this:

- Enable the formatter only on certain pages (is this possible?), keep
restrictive ACLs on those pages, and make sure visitors and
contributors are informed about the risks of using the site.
- Enable the formatter only for localhost clients, and setup a
read-only proxy on the same machine that is accessed through a
distinct domain name, so that normal protections against cross-site
scripting block access to the wiki.
- Only generate JSON (from tables or yaml snippets) and maybe invent a
simple DSL or two that could be translated to reliably safe
javascript, for operations over the JSON data.

Creating a formatter that just spits out JSON from data in the page should be quite safe. Then you (the site owner) have some javascript code in the theme that grabs this json and does interesting things with it. 

Allowing a user to insert Javascript (or a DSL later converted to JS) in the page that is then run in a browser by whomever later comes to view that page is not a good plan. 

Matthew Nuzum
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"An investment in knowledge pays the best interest." -Benjamin Franklin