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Fonts blocking question

Posted: Wed Apr 10, 2019 1:33 pm
by randomnoscriptuser
Hi,

I'm blocking fonts with Noscript in Firefox 66.0.2 but this site knows how many fonts are installed on my pc:

http://ip-check.info/?lang=en

In Tor Browser this site can't regonize how many fonts I actually have.

Re: Fonts blocking question

Posted: Wed Apr 10, 2019 1:50 pm
by barbaz
Moving to NoScript General.

NoScript's font blocking blocks REMOTE fonts, i.e. fonts that are downloaded from a web server and used 'on-the-fly'. It doesn't block fonts that are already on your computer; you've already decided you trust those fonts enough to install them system-wide, there's no security benefit to blocking them.

Re: Fonts blocking question

Posted: Wed Apr 10, 2019 1:54 pm
by Giorgio Maone
randomnoscriptuser wrote: Wed Apr 10, 2019 1:33 pm In Tor Browser this site can't regonize how many fonts I actually have.
In facts, the Tor Browser prevents web pages from using any system-installed font except the most common 4 (one for each "family") from being used by any page, in order to make its users more difficult to tell apart.
However you need scripts in order to enumerate the local fonts.
This however has nothing to do with blocking remote typefaces, which is what the "font" permission does in NoScript.

Re: Fonts blocking question

Posted: Sat Apr 13, 2019 9:53 am
by randomnoscriptuser
Oh, You're right, it seems I misunderstood this function :)

I have "regural" Firefox and Tor Browser (both with NoScript) and I got different results at ip-check.info. I thought that NoScript blocks pages from using system-installed fonts to avoid fingerprinting. Is there any way to do this with NoScript?

Re: Fonts blocking question

Posted: Sat Apr 13, 2019 11:40 am
by Giorgio Maone
randomnoscriptuser wrote: Sat Apr 13, 2019 9:53 am Is there any way to do this with NoScript?
Other than disabling scripts, none.
Preventing the rendering engine from using local fonts requires forcibly "blinding" the browser about them: something which is in reach of a Firefox fork (like the Tor Browser) but not of an extension.