Microsoft just released support for certificate-based authentication (CBA) for the Microsoft Azure Information Protection iOS app. The app integrates with the Microsoft Authenticator app that supports the Apple iOS SafariViewController that enables access to the certificates stored on the iOS device.
This post applies to Microsoft Web Application Proxy 2012 R2. I recommend that you upgrade to Windows Server 2016 that provides a built-in function within the Web Application Proxy 2016 to perform HTTP to HTTPS direct. See more here Updated post: This post has been updated 07/32/2017. Original post: 25.