I have a site on A.com and an iframe on B.com which reads info from A.com. I realize that there is some problems with third party cookies, iframes and P3P - particularly in Safari [my problem]
Is it possible to instead, use AJAX or a hidden iFrame to pass the cookie information from A.com to B.com which will then "recreate" another cookie with the same information on the iframe in B.com.
I am trying to do this for authenication - i.e. a user is logged in on A.com and then goes to b.com and the iframe is also logged in ?
I was hoping to perhaps pass the data in a hidden iframe and "recreate" the cookie in the iframe on B.com using JavaScript? Is this possible ? Security issues ? What about HTTPS?
I'm afraid you're out of luck. In Safari and IE8, it's impossible to set a cookie in a domain which is not the primary document's domain.
So, in other words, you can only set cookies for a domain which is visible in the address bar. There are no tricks to get around this problem.
来源：https://stackoverflow.com/questions/2948130/iframes-and-cookies