HADOOP-13381 added support to use KMS delegation token to connect to KMS server for key operations. However, the logic to check if the UGI container KMS delegation token assumes that the token must contain a service attribute. Otherwise, a KMS delegation token won't be recognized.
For delegation token obtained via non-java client such curl (http), the default DelegationTokenAuthenticationHandler only support renewer parameter and assume the client itself will add the service attribute. This makes a java client with KMSClientProvdier can't use for KMS delegation token retrieved form non-java client because the token does not contain a service attribute.
I did some investigation on this and found two solutions:
1. Similar use case exists for webhdfs, and webhdfs supports it with a "service" parameter.
We can do this similarly by allowing client to specify a service attribute in the request URL and included in the token returned like webhdfs. Even though this will change in DelegationTokenAuthenticationHandler and may affect many other web component, this seems to be a clean and low risk solution because it will be an optional parameter. Also, other components get non-java client interop support for free if they have the similar use case.
2. The other way to solve this is to release the token check in KMSClientProvider to check only the token kind instead of the service. This is an easy work around but seems less optimal to me.
cc: Xiao Chen for additional input.