[whatwg] Need to define same-origin policy for WebIDL operations/getters/setters
bzbarsky at MIT.EDU
Tue Jan 8 05:14:13 PST 2013
On 1/8/13 2:09 AM, Ian Hickson wrote:
> In the spec's security model, origins are never relevant for elements
> except when we're looking at the element's data.
Yes. I think the spec's security model is not viable long-term, for
what it's worth, and think we should be designing a security model that
is instead... But that's a separate discussion.
>> Is that actually needed? There are properties you can obtain on objects
>> cross-origin (like window.top) that I see no need to allow via this
>> backdoor since no content depends on it now. So I would prefer simply
>> checking whether the origin of the caller matches the origin of "this".
> Well right now "this" doesn't necessarily have an origin.
Yes, but that's a fixable problem.
> Also, consider Location. If you have a Location object and then navigate its browsing
> context and then call something on it, you need to check that the calling
> script doesn't match the origin of the new active document, not the origin
> of the Location object's Window's Document.
I'm not touching Location with a 10-foot pole. That's all Bobby. ;)
Seriously, though, fitting Location into any sort of security setup is
> Doing a check on _every_ call seems rather expensive for implementations
> that don't use Gecko's security model compared to only doing a check on
> those interfaces that matter.
Clearly I think Gecko's security model is the right one. ;)
Seriously, though, I'm very much unconvinced by the spec's security
model. But you already knew that.
> A Location object has multiple prototypes (one for each origin that
> accesses it).
That's a pretty new development, no? In any case, I agree that
specifically for Location (and perhaps Window) there needs to be weirdness.
> For Storage, the access check has to be the actual origin of the Document,
> not the effective script origin as it does for Window and Document.
That's a separate check from whether you can even touch the object, no?
Certainly that's how it works in Gecko: first there is a generic check
for whether you can touch the object at all, then for Storage a second
Note that this situation is similar to data origins for images and
whatnot: those are also checked against origins, not effective script
origins. I don't see the problem here.
> Assuming the script's effective script origin is not the same as the
> crossOriginDoc's effective script origin, it doesn't matter _what_
> myGetter points to. It should always throw, either TypeError (or some
> such) if myGetter points to something that's not on Document somehow, or
> SecurityError, if myGetter points to something that _is_ on Document.
Well, or TypeError in both cases, yes. But OK, we agree on this, good. :)
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