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Re: Blob URL Origin

From: Anne van Kesteren <annevk@annevk.nl>
Date: Mon, 19 May 2014 11:00:15 +0200
Message-ID: <CADnb78hPTea-WT4EXKcWwonF5mxgmSgb75D9S16Eo9zNerdTig@mail.gmail.com>
To: Jonas Sicking <jonas@sicking.cc>
Cc: Adam Barth <w3c@adambarth.com>, Joel Weinberger <jww@google.com>, Boris Zbarsky <bzbarsky@mit.edu>, WebApps WG <public-webapps@w3.org>
On Mon, May 19, 2014 at 10:30 AM, Jonas Sicking <jonas@sicking.cc> wrote:
> In at least Chrome and Firefox, blob: acts like filesystem: and can't
> be loaded cross-origin. Even in cases when we normally permit loading
> of cross-origin resources like in <img> and <script>.
>
> This has been to prevent websites from being able to steal data by
> guessing UUIDs (at least the Gecko UUID generator isn't guaranteed to
> produce unguessable UUIDs).
>
> So the question of <canvas> tainting doesn't really come into play,
> since you can't even load the cross-origin blob: into an image and
> draw it into the canvas.

Again fair, but do we consider that something we want to fix or do we
want to enshrine this?


-- 
http://annevankesteren.nl/
Received on Monday, 19 May 2014 09:00:45 UTC

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