`AuthParamsStringCredentials` never authenticates on the native Pulsar client

[illyrianks]

Setting a credential with "type":"authParamsString" — via DEKAF_DEFAULT_PULSAR_AUTH or a session credential — makes every binary-protocol connection fail with:

PulsarClientException$AuthenticationException: Failed to authenticate

This happens regardless of the auth plugin, and regardless of whether authParams is a literal value or a file:// reference. The same broker/token works fine with "type":"jwt".

Repro:

{"type":"authParamsString","authPluginClassName":"org.apache.pulsar.client.impl.auth.AuthenticationToken","authParams":"<valid token>"}
→ fails on connect/consume/produce.
{"type":"jwt","token":"<same token>"}
→ works.

Root cause: server/src/main/scala/pulsar_auth/Client.scala, configureAuth (used by makePulsarClient, the native binary-protocol client). The AuthParamsStringCredentials case only does:
pulsarClientConfig.setAuthPluginClassName(cr.authPluginClassName)
pulsarClientConfig.setAuthParams(cr.authParams)
Unlike the Jwt/OAuth2 cases just above it, it never calls setAuthentication(...) with an actual Authentication object. Since the client is built directly via PulsarClientImpl.builder().conf(pulsarClientConfig)...build() (bypassing ClientBuilderImpl, which normally does this string→object conversion), the raw strings never become a live Authentication instance — the client connects with none attached.


Suggested fix:
case cr: AuthParamsStringCredentials =>
    pulsarClientConfig.setAuthPluginClassName(cr.authPluginClassName)
    pulsarClientConfig.setAuthParams(cr.authParams)
    pulsarClientConfig.setAuthentication(AuthenticationFactory.create(cr.authPluginClassName, cr.authParams))

[visortelle]

@illyrianks thank you for reporting this.
Could you please provide the Dekaf version you use.

We had fixes on AuthParamsStringCredentials in v1.1.1.
If you run >= v1.1.1, I'll recheck.

[illyrianks]

v1.2.1, that suggested fix would resolve also token refresh. If you can implement this and create a new release.

[visortelle]

Thanks, I'll fix it.

I'll let you know when it will be ready.