Our environment is Sharepoint 2010, with a web application created (and site collection on top), using claims based authentication. The first site is using port 881. It is using integrated windows authentication. Another web application is created, extending the first application, using port 882. This site is using Forms Based Authentication, the membership provider is System.Web.Security.ActiveDirectoryMembershipProvider, named admembers. I have turned off Client Integration on both sites.
When I login to the 881 site, on my corporate network, logged into the machine with the same domain account that sharepoint uses, I can open an Office file saved in a document library, and it subsequently opens in the appropriate Office application, without asking me login again. But, If I login to Sharepoint from a computer that is not on our network, or login to the computer with an account that is not a domain account, I get prompted again to login when openning an Office document. If I choose the option to save, it does not prompt, but if I choose open in the dialog window, I am forced to enter my domain credentials again.
When I login to the 882 site, which uses FBA, I experience the same problem. If I open an Office document, the appropriate Office application opens, and asks me for my credentials, by showing me a dialog window with the sign in page loaded. If I choose to save the file, then I am not prompted to login, and the file saves to a local folder.
I can't expect my users that are off site to login again everytime they open an Office document, like Work, Excel, Powerpoint, etc. I have tried numerous fixes, including disabling client integration, changing the browser handling mode (strict/permissive), changing internet explorer settings (for integrated windows authentication), changing the integrated windows authentication site to use basic authentication, even hacking the page using jquery to call the sharepoint javascript function that execute the "download a copy" function. None of them work: when choosing to "open" the Office document in the browser, the user has to login again, or just close the dialog window without logging in (as long as client integration for the zone is turned off).
I'm looking to get this accomplished using windows authentication or forms based authentication.
Help!