Hi folks, I’d like to get feedback on how Polaris should carry richer authentication-derived inputs into authorization. Today, Polaris passes a single PolarisPrincipal into authorization, and I think PolarisPrincipal should remain the canonical resolved identity Polaris authorizes as. At the same time, an authorizer may need additional inputs derived during authentication, such as subject information distinct from the acting client, or provenance/delegation information. This feels increasingly relevant as the Iceberg community discusses features such as ReadRestrictions [1], where the acting client and the end user may be distinct and policies may evolve to inspect both.
One option is to enhance PolarisPrincipal with additional well-known fields for concepts like subject or provenance. The alternative I am considering is to keep PolarisPrincipal focused on canonical identity and introduce a separate AuthorizationContext that an Authenticator can optionally produce and a PolarisAuthorizer can optionally consume. In that model, polaris-core would be a passthrough but would not interpret or normalize the contents, and specific authorizer implementations such as OpaPolarisAuthorizer could project them as needed to its policy decision point. The idea is that the Authenticator could inspect a PolarisCredential attribute via getToken() [2] and populate the AuthorizationContext. Before I push further on implementation, I’d like community feedback on which direction seems more appropriate. Should Polaris standardize these concepts in PolarisPrincipal, or should it stay generic and use a separate AuthorizationContext instead? And if the separate-context direction is preferred, would evolving the Authenticator SPI to return PolarisPrincipal plus optional context be a reasonable next step? Cheers, and looking forward to your feedback on this idea. Sung [1] https://lists.apache.org/thread/hvsyrmpvok4wdp6prdkyp78l98v6o95c [2] https://github.com/apache/polaris/blob/f39a9a38c6b6d08b26f2f90713e54808f4062218/runtime/service/src/main/java/org/apache/polaris/service/auth/PolarisCredential.java#L64
