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Re: Clipboard API: remove dangerous formats from mandatory data types

From: Wez <wez@google.com>
Date: Wed, 24 Jun 2015 15:44:36 +0000
Message-ID: <CALekkJeux3W6UqZAHaUPRHnK-SzJSJR-A7zRC5wCH-3Lm6Ep9w@mail.gmail.com>
To: Hallvord Reiar Michaelsen Steen <hsteen@mozilla.com>
Cc: Daniel Cheng <dcheng@google.com>, public-webapps <public-webapps@w3.org>
Hallvord,

Yes, content would be limited to providing text, image etc data to the user
agent to place on the clipboard, and letting the user agent synthesize
whatever formats (JPEG, PNG etc) other apps require. That has the advantage
of preventing malicious content using esoteric flags or features to
compromise recipients, but conversely means that legitimate content cannot
use format-specific features, e.g. content would not be able to write a
JPEG containing a comment block, geo tags or timestamp information.



Wez


On Sat, 13 Jun 2015 at 11:57 Hallvord Reiar Michaelsen Steen <
hsteen@mozilla.com> wrote:

> On Thu, Jun 11, 2015 at 7:51 PM, Wez <wez@google.com> wrote:
>
>> Hallvord,
>>
>> The proposal isn't to remove support for copying/pasting images, but to
>> restrict web content from placing compressed image data in one of these
>> formats on the clipboard directly - there's no issue with content pasting
>> raw pixels from a canvas, for example, since scope for abusing that to
>> compromise the recipient is extremely limited by comparison to JPEG, PNG or
>> GIF.
>>
>
> Well, but as far as I can tell we don't currently *have* a way JS can
> place pixels from a canvas on the clipboard (except by putting a piece of
> data labelled as image/png or similar there). So if you're pushing back
> against the idea that JS can place random data on the clipboard and label
> it image/png, how exactly would you propose JS-triggered copy of image data
> to work? Say, from a CANVAS-based image editor?
> -Hallvord
>
>
Received on Wednesday, 24 June 2015 15:45:15 UTC

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