On Javascript Postmessage To Parent Html Iframe That Is On Local Disk

I am working on a project that involves hosting a webpage in a iframe, while the hosting parent iframe is in a HTML file on local disk, say on c:\; while the inner hosted iframe is

Solution 1:

I don't know how to specify "file", I'm guessing there is no way because it doesn't make much sense. The purpose of the origin is to prevent others (presumably malicious) pages from seeing your message, but if the origin is just any file on the hard disk, anyone could see it by creating an html file with a frame and loading your web page from your server. So specifying "file" (even if there were a way) is no more secure than specifying " * ", so just use " * " and save yourself the headache.