I need to make an asynchronous call to a secure (HTTPS) URL for the same domain.
Currently the page is working with regular HTTP (non-secure).
In other word
First of all, I've +1 both questions from @missingo and @PiTheNumber.
After spending a lot of hours, I've arrived to the conclusion I'm going to switch the entire page to HTTPS. That's because:
Most moderns browsers support CORS, but Internet Explorer, starting from 8th version has a proprietary implementation (XDomainRequest object), which may be disabled in some computers (mine had cross-domain request disabled by default in Internet security zone).
Opera doesn't support CORS. 12th version will support it, but this isn't an option as users should adopt this new version first, and this won't be in 2 days.
I need to do cross-domain requests since Web client application must request a RESTful service layer located in another domain. No way.
Switching everything to HTTPS makes the service layer proxy approach work again (this is the expected behavior).
Thanks anyway because both answer have helped me a lot for arriving to this conclusion.
@Sam has added a comment that could be interesting for anyone. It's about how to get CORS in Internet Explorer 8 and 9 (see #7): http://blogs.msdn.com/b/ieinternals/archive/2010/05/13/xdomainrequest-restrictions-limitations-and-workarounds.aspx