In order for Slider and Knox to work securely it must be possible to setup a trust relationship between the two. This is commonly done in other Hadoop ecosystem components using a combination of Kerberos/SPNego and a doas URL query parameter. This provides a mechanism for AM to strongly authenticate Knox as a trusted proxy, ensuring that it can trust the identity assertions made via the doas query parameter. The links below provide some information describing how this is done for core Hadoop. Also note that most components utilize Hadoop core's reusable hadoop-auth module to implement this functionality.