#20317: Key permissions by first-party domain instead of origin (proposal)
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Reporter: arthuredelstein | Owner: tbb-team
Type: defect | Status: new
Priority: Medium | Milestone:
Component: Applications/Tor Browser | Version:
Severity: Normal | Resolution:
Keywords: tbb-linkability | Actual Points:
Parent ID: | Points:
Reviewer: | Sponsor:
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Description changed by arthuredelstein:
Old description:
> In Firefox (and current Tor Browser), permissions are keyed by origin.
> That is a tracking vector -- for example, on Google maps, if click on the
> "Show your Location" button,
>
> [[Image(location.png)]]
>
> The browser asks "www.google.com: Would you like to Share your Location
> with this site?" If we choose "Always Share Location", then this
> permission is stored, keyed to www.google.com.
>
> [[Image(permission.png)]]
>
> Now the UI says "this site", which is, to my ear, synonymous with "first
> party domain". But now on other sites, any third-party object from
> www.google.com" (such as a Google Analytics script or a Google+ button)
> can know our location. And, further, it can expose a function call that
> any other script on the same page could call to obtain our location. So
> in practice, we have given permission for numerous domains to obtain our
> location. And the very existence of the unusual permission setting, or
> any other, helps to track us.
>
> So I would like to propose that we key every permission by first-party
> domain instead of origin domain. That means that the Permissions UI
> doesn't need to change much at all. We are still assigning each
> permission to a single domain. But this way, granting a permission to
> google.com would not leak to every other site.
>
> And I would argue that this is already the perception of most users when
> they see a permission requested for "this site". Most users are not
> knowledgeable about the subtleties of third-party scripts -- they expect
> a permission to apply to the site they are visiting (the first party).
>
> I would suggest we should write this patch for ESR52, which means using
> Origin Attributes and the pref "privacy.firstparty.isolate". Then we can
> hopefully uplift to Mozilla.
New description:
In Firefox (and current Tor Browser), permissions are keyed by origin.
That is a tracking vector -- for example, on Google maps, if click on the
"Show your Location" button,
[[Image(location.png)]]
The browser asks "www.google.com: Would you like to Share your Location
with this site?" If we choose "Always Share Location", then this
permission is stored, keyed to www.google.com.
[[Image(permission.png)]]
Now the UI says "this site", which is, to my ear, synonymous with "first
party domain". But now on other sites, any third-party iframe from
www.google.com (such as created by a Google Analytics script or a Google+
button) can know our location. And, further, it can expose a function call
(using iframe postMessage tricks) that any other script on the same page
could call to obtain our location. So in practice, we have given
permission for numerous domains to obtain our location. And the very
existence of the unusual permission setting, or any other, helps to track
us.
So I would like to propose that we key every permission by first-party
domain instead of origin domain. That means that the Permissions UI
doesn't need to change much at all. We are still assigning each permission
to a single domain. But this way, granting a permission to google.com
would not leak to every other site.
And I would argue that this is already the perception of most users when
they see a permission requested for "this site". Most users are not
knowledgeable about the subtleties of third-party scripts -- they expect a
permission to apply to the site they are visiting (the first party).
I would suggest we should write this patch for ESR52, which means using
Origin Attributes and the pref "privacy.firstparty.isolate". Then we can
hopefully uplift to Mozilla.
--
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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/20317#comment:2>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
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