On Fri, Nov 22, 2002 at 11:03:07PM +0100, Michael Schierl wrote:
> Hi,
> 
> Seems that I found a rather big "hole" in fproxy's anonymity filter:
> 
> 
> when you insert a file encoded in UTF16 with a proper byteorder mark at
> the beginning (i.e. FFFE or FEFF), it is understood by most of the
> browsers.
Not any more. Fproxy now supports text/html?charset=<some charset
supported by your JVM>. If no charset is specified, it is forced in the
browser (by headers) to be ISO-8859-1, the default. It is filtered using
the charset specified. So fproxy now has proper I18N support, and it is
filtered properly too. I wanna see some wierd charset pages on freenet
now people! :)

Testing would be appreciated, as would more anon filter bugs.
> 
> (btw it is the only way I know of using national chars that don't have a
> textual entity in HTML files on Freenet at all, as charset=UTF8 meta
> tags are blocked by the anonymity filter. Allowing those would be
> better, I think.)
They are still blocked. IMHO we should allow charset specification at
the headers level, so we can filter it safely - anything else leads to
horrible ambiguity and major code bloat.
> 
> Despite that, fproxy's anonymity filter lets it go through without
> finding anything in it - e. g. images loaded from the web will pass
> without warning. 
Not any more.
> 
> I inserted two sample files at
> 
> SSK at eUBIUpjnEDHs3oUm4SlPEtQdrH0PAgM/ascii.html
This trips the filter now.
> SSK at eUBIUpjnEDHs3oUm4SlPEtQdrH0PAgM/unicode.html
This gets displayed as ISO-8859-1, so looks like crap, but is harmless.
At least in Mozilla. IE probably autodetects it and shows the hole, but
if you use IE you're wide open anyway due to the MIME type
autodetection.
> 
> Both the same "source" text, but the first one in ASCII (causes a fproxy
> warning) and the second one in UTF-16 (does not cause one).
> 
> Michael
> 

-- 
Matthew Toseland
toad at amphibian.dyndns.org
amphibian at users.sourceforge.net
Freenet/Coldstore open source hacker.
Employed full time by Freenet Project Inc. from 11/9/02 to 11/1/03
http://freenetproject.org/
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