[KAFKA-3166] Disable SSL client authentication for SASL_SSL security protocol

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.0.0
• Fix Version/s: 0.9.0.1
• Component/s: security
• Assignee: Ismael Juma
• Reporter: Ismael Juma
• Reviewer: sriharsha chintalapani
• Created: 28/Jan/16 20:15
• Updated: 29/Jan/16 13:09
• Resolved: 29/Jan/16 13:09

Description

A useful scenario is for a broker to require clients to authenticate either via SSL or via SASL (with SASL_SSL security protocol). With the current code, this is not possible to achieve. If we set `ssl.client.auth` to `required`, then it will be required for both SSL and SASL.

I suggest we hardcode `ssl.client.auth` to `none` for the `SASL_SSL` case.