Re: [NavigationTiming] navigationStart in Cross-origin redirects

On Tue, Apr 5, 2011 at 3:23 AM, Sigbjørn Vik <sigbjorn@opera.com> wrote:
> On Mon, 04 Apr 2011 19:37:50 +0200, Zhiheng Wang <zhihengw@google.com>
> wrote:
>
>>   Meanwhile, by timing iframe loading time and other techniques,
>> a malicious page can already estimate the time it takes to load a page
>> including HTTP redirects so exposing navigationStart doesn't make it worse
>> in terms of user privacy
>>
>> [4]<http://lists.w3.org/Archives/Public/public-web-perf/2010Oct/0066.html>.
>> So
>> I would propose
>> to lift the SOP constraint on navigationStart in case of redirect.
>>
>>   Thoughts and comments?
>
> I cannot immediately think of any reasons we have to block navigationStart,
> so should be fine with me.

+1

The initial Chrome implementation didn't block navigationStart for
cross origin redirects and the internal security/privacy review was
okay with that. I'm interested to hear whether IE and FF are
comfortable exposing it in this case.

>
>>   On a related note, I can't think of a real-life example where domain A
>> redirects to domain B while exposing the redirect time and count on
>> domain A is harmful, given that only HTTP redirects are considered here.
>> Any one can provide a case for it? We should include it in the
>> spec.
>
> Many sites will redirect a visitor differently depending on the user being
> logged in/having a cookie or not. There might be one extra redirection step
> to set a cookie, even before a site redirects a visitor to the final
> destination. The presence of the extra redirection step will leak
> information about a user's history. Exact redirect timings will also reveal
> if any DNS information is cached.
>
> --
> Sigbjørn Vik
> Quality Assurance
> Opera Software
>
>

Received on Tuesday, 5 April 2011 16:35:36 UTC