I got it to work, but the solution is a bit complex, so bear with me.
In this case, when cookies are blocked, session identifier is not sent, and the target script throws a 'session not found' error.
(I've tried setting the session identifier into the form and loading it from POST variables. This would have worked, but for political reasons I couldn't do that.)
How to solve it
Create a p3p policy
(e.g. "the site is operated by ACME Ltd., it uses anonymous per-session identifiers for its operation, collects user data only if explicitly permitted and only for the following purposes, the data is stored only as long as necessary, only our company has access to it, etc. etc.").
(When editing with this tool, it's possible to view errors/omissions in the policy. Also very useful is the tab "HTML Policy": at the bottom, it has a "Policy Evaluation" - a quick check if the policy will be blocked by IE's default settings)
The Editor exports to a .p3p file, which is an XML representation of the above policy. Also, it can export a "compact version" of this policy.
Link to the policy
Then a Policy Reference file (
http://example.com/w3c/p3p.xml) was needed (an index of privacy policies the site uses):
<INCLUDE> shows all URIs that will use this policy (in my case, the whole site). The policy file I've exported from the Editor was uploaded to
Send the compact header with responses
I've set the webserver at example.com to send the compact header with responses, like this:
HTTP/1.1 200 OK
P3P: policyref="/w3c/p3p.xml", CP="IDC DSP COR IVAi IVDi OUR TST"
// ... other headers and content
policyref is a relative URI to the Policy Reference file (which in turn references the privacy policies),
In this configuration, the Evil Eye does not appear, the cookies are saved even in the IFRAME, and the application works.
Edit: What NOT to do, unless you like defending from lawsuits
Several people have suggested "just slap some tags into your P3P header, until the Evil Eye gives up".
The tags are not only a bunch of bits, they have real world meanings, and their use gives you real world responsibilities!
For example, pretending that you never collect user data might make the browser happy, but if you actually collect user data, the P3P is conflicting with reality. Plain and simple, you are purposefully lying to your users, and that might be criminal behavior in some countries. As in, "go to jail, do not collect $200".
A few examples (see p3pwriter for the full set of tags):
- NOI : "Web Site does not collected identified data." (as soon as there's any customization, a login, or any data collection (***** Analytics, anyone?), you must acknowledge it in your P3P)
STP but don't have a retention policy, you may be committing fraud. How cool is that? Not at all.)
I'm not a lawyer, but I'm not willing to go to court to see if the P3P header is really legally binding or if you can promise your users anything without actually willing to honor your promises.
You can use the IWebBrowser2::get_LocationURL method.