Support has been added for TLS channel binding tokens for Negotiate/Kerberos authentication over HTTPS through javax.net.HttpsURLConnection.

Channel binding tokens are increasingly required as an enhanced form of security. They work by communicating from a client to a server the client's understanding of the binding between connection security (as represented by a TLS server cert) and higher level authentication credentials (such as a username and password). The server can then detect if the client has been fooled by a MITM and shutdown the session/connection.

The feature is controlled through a new system property `jdk.https.negotiate.cbt` which is described fully at the following page: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/net/doc-files/net-properties.html#jdk.https.negotiate.cbt