Re: Remove paths from CSP?

On Tue, Jun 3, 2014 at 11:32 AM, Sigbjørn Vik <sigbjorn@opera.com> wrote:

> Images can normally be served static from a site, so is not the main
>  problem, and no different than the existing problem. For documents, the
> question is if the "blank" page can be distinguished from the normal
> login page.


Leaving images aside (because you're right, they prove too much) the sorts
of attacks detailed in
http://www.contextis.com/documents/2/Browser_Timing_Attacks.pdf would still
worry me.


> For a suitable definition of "blank", this should be hard,
> and it should be possible for webmasters to make their login pages look
> just like the "blank" page to further minimize that chance.
>

I think I'm missing this point. A blank login page would be not
particularly useful. What does "blank" mean to you? :)


> One of my concerns is that we will open a new hole which webmasters
> cannot close. A solution might be to add a CSP HTTP header when doing
> cross-domain requests which may be used for redirection detection. This
> would enable webmasters so inclined to detect such requests, and always
> give the same response.


Interesting. How does this work?

Assume that `evil.com` triggers a request to `example.com/loggedin` (which
redirects to `accounts.example.com`). What would be sent in the header
along with the request to `example.com`? The active policy of the page
requesting the resource?

Does that have properties significantly different from the `Referer` or
`Origin` headers?

-mike