This Confluence has been LDAP enabled, if you are an ASF Committer, please use your LDAP Credentials to login. Any problems file an INFRA jira ticket please.

Child pages
  • KIP-203: Add toLowerCase support to sasl.kerberos.principal.to.local rule
Skip to end of metadata
Go to start of metadata

This page is meant as a template for writing a KIP. To create a KIP choose Tools->Copy on this page and modify with your content and replace the heading with the next KIP number and a description of your issue. Replace anything in italics with your own description.

Status

Current state: Accepted

Discussion thread: here 

JIRA: KAFKA-5764 - Getting issue details... STATUS

Please keep the discussion on the mailing list rather than commenting on the wiki (wiki discussions get unwieldy fast).

Motivation

From Kafka documentation 

"By default, the SASL user name will be the primary part of the Kerberos principal. One can change that by
setting sasl.kerberos.principal.to.local.rules to a customized rule in server.properties. The format of
sasl.kerberos.principal.to.local.rules is a list where each rule works in the same way as
the auth_to_local in Kerberos configuration file (krb5.conf)  

Each rules starts with RULE: and contains an expression in the format [n:string](regexp)s/pattern/replacement/g."

Currently, username translations based on rules are done maintaining the case of the input principal. For example, given the rule

"RULE:[2:$1@$0](.*@EXAMPLE.COM)s/@.*//"
If the source string is joe-qa/host@EXAMPLE.COM, the result is joe-qa
If the source string is JOE-QA/host@EXAMPLE.COM, the result is JOE-QA
If the source string is Joe-QA/host@EXAMPLE.COM, the result is Joe-QA

However, this may not be desired given how different operating system handle usernames, whereas some are case-sensitive

and some are case-insensitive. For example, Linux is case-sensitive and Windows is case-insensitive.

To help with this issue, the rule can support to force the translated result to be all lower case.

Reference

  1. https://community.hortonworks.com/articles/14463/auth-to-local-rules-syntax.html

Proposed Changes

We propose to extend "sasl.kerberos.principal.to.local.rules"  config rule format/syntax by supporting an optional  "/L" (toLowerCase) at the end of the rule. Since usernames are locale insensitive strings, we propose to use Locale.ENGLISH for the case conversion

 For example, given the rules

"RULE:[2:$1@$0](joe-qa-.*@EXAMPLE.COM)s/.*/JOE-QA//L",
"RULE:[2:$1@$0](JOE-QA-.*@EXAMPLE.COM)s/.*/JOE-QA-UPPER//L",
"RULE:[2:$1@$0](.*@EXAMPLE.COM)s/@.*///L"
If the source string is joe-qa-cl1/host@EXAMPLE.COM, the result will be joe-qa
If the source string is JOE-QA-cl1/host@EXAMPLE.COM, the result will be joe-qa-upper
If the source string is joe_user/host@EXAMPLE.COM, the result will be joe_user
If the source string is JOE_USER/host@EXAMPLE.COM, the result will be joe_use

 

However, it must be noted that this does not affect how pattern matches on input and therefore that will still be case-sensitive.

Compatibility, Deprecation, and Migration Plan

  • No labels