...

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:  ["Under Discussion"] Accepted

Discussion thread: here [Change the link from the KIP proposal email archive to your own email thread]
 

JIRA:

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

...

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

"RULE:[12:$1@$0](.*@EXAMPLE.COM)s/@.*//"

If the source string is joe-qa@EXAMPLEqa/host@EXAMPLE.COM, the result is joe-qa
If the source string is JOE-QA@EXAMPLEQA/host@EXAMPLE.COM, the result is JOE-QA
If the source string is Joe-QA@EXAMPLEQA/host@EXAMPLE.COM, the result is Joe-QA

However, this may not be desired given how different operating system handle usernames, whereas where 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. However, it must be noted that this does not affect how pattern matches on input and therefore that will still be case-sensitive. Since usernames are locale insensitive strings, we propose to use Locale.ENGLISH for the case conversion

 For example, given the rules

"RULE:[2

RULE:[1:$1@$0](joe-qa-.*@EXAMPLE.COM)s/.*/JOE-QA//L",
"RULE:[12:$1@$0](JOE-QA-.*@EXAMPLE.COM)s/.*/JOE-QA-UPPER//L",
"RULE:[12:$1@$0](.*@EXAMPLE.COM)s/@.*///L"

If the source string is joe-qa-cl1@EXAMPLEcl1/host@EXAMPLE.COM, the result iswill be joe-qa
If the source string is JOE-QA-cl1@EXAMPLEcl1/host@EXAMPLE.COM, the result iswill be joe-qa-upper
If the source string is joe_user@EXAMPLEuser/host@EXAMPLE.COM, the result iswill be joe_user
If the source string is JOE_USER@EXAMPLEUSER/host@EXAMPLE.COM, the result iswill 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

• This is an extension to the existing sasl.kerberos.principal.to.local.rules format and there will be no impact on existing users.

Rejected Alternatives

...

• .