Apache Pulsar allows an administrator to require end-to-end message encryption for all topics in...

Apache Pulsar allows an administrator to require end-to-end message encryption for all topics in a namespace by setting the encryption_required namespace policy. When this policy is set, the broker rejects messages that are published without encryption.

When the broker loads a persistent topic, it reads the namespace policies and the topic-level policies as part of topic initialization. If a step of this initialization fails, for example because of an error reading from the metadata store, a failure loading the topic-level policies or a failure in a later initialization step, the broker logs a warning, disables the encryption requirement for that topic, and completes the topic load as if it had succeeded. The topic is then served with encryption_required not enforced, even though the namespace policy requires it. Topic-level policies that could not be loaded are also not applied.

While the encryption requirement is not enforced, an authenticated client with permission to produce to the affected topic can publish messages that are not encrypted, and the broker accepts and stores them. This applies both to producers created after the topic was loaded and to producers that were already connected. Messages published with encryption remain encrypted; the issue does not expose the content of encrypted messages or the encryption keys.

The condition is not limited to transient failures. If the cause of the initialization failure persists, the encryption requirement is disabled aga…