KAFKA-15878: KIP-768 - Extend support for opaque (i.e. non-JWT) tokens in SASL/OAUTHBEARER

[jcme]

Overview

• This change pertains to SASL/OAUTHBEARER mechanism of Kafka authentication.
• Kafka clients can use SASL/OAUTHBEARER mechanism by overriding the custom call back handlers .
• KIP-768 available from v3.1 further extends the mechanism with a production grade implementation.
• Kafka's SASL/OAUTHBEARER mechanism currently rejects the non-JWT (i.e. opaque) tokens. This is because of a more restrictive set of characters than what RFC-6750 recommends.
• This JIRA can be considered an extension of KIP-768 to support the opaque tokens as well apart from the JWT tokens.

Solution

• Have updated the regex in the the offending class to be compliant with the RFC-6750
• Have provided a supporting test case that includes the possible character set defined in RFC-6750

[kirktrue]

@jcme—I wrote and implemented KIP-768, so I'll take a look at this.

Also, are you able to assign the Jira to yourself? Thanks!

[kirktrue]

@jcme—Can you trigger a rebuild of the CI job? It looks like the last run didn't work.

[omkreddy]

@jcme Thanks for the PR. Can you pls rebase the PR to latest trunk?

[philomathanuj]

Thanks very much @kirktrue, @omkreddy for reviewing the PR. Could you help with merging the PR please?