[KAFKA-10556] NPE if sasl.mechanism is unrecognized

• Type: Task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.7.0
• Assignee: Ron Dagostino
• Reporter: Ron Dagostino
• Created: 30/Sep/20 15:38
• Updated: 22/Nov/23 14:12
• Resolved: 01/Oct/20 13:39

Description

If a client sets an unknown sasl.mechanism value (e.g. mistakenly setting "PLAN" instead of "PLAIN") the client sees a NullPointerException that only indirectly indicates the nature of the problem. For example:

java.lang.NullPointerException
at org.apache.kafka.common.security.authenticator.SaslClientAuthenticator.sendSaslClientToken(SaslClientAuthenticator.java:430)

It is better to see an exception that directly states what the issue is. For example, the initial version of this PR would provide the following information:

Caused by: org.apache.kafka.common.errors.SaslAuthenticationException: Failed to create SaslClient with mechanism PLAN

Issue Links

• is duplicated by: KAFKA-9497 Brokers start up even if SASL provider is not loaded and throw NPE when clients connect
• is duplicated by: KAFKA-7631 NullPointerException when SCRAM is allowed bu ScramLoginModule is not in broker's jaas.conf
• links to: GitHub Pull Request #9356
• links to: GitHub Pull Request #9372