[zeromq-dev] Can a broker explicitly deny certain subscriptions to certain clients?

[David Jelenc]

Hi,

I'm wondering if there is a way to explicitly deny a certain client from 
subscribing to a certain topic.

I have a broker set up, where some clients publish and other subscribe.

  client                              client
PUBLISHER -------- BROKER -------- SUBSCRIBER

PUB --- (XSUB | broker  logic | XPUB) --- SUB

Since I'm using a XPUB socket on the broker, I can see all subscription 
and subscription cancellation messages. However, once these messages 
reach broker, the client is already subscribed.

Is there any way on how I can prevent a client from subscribing to 
certain topics (while allowing the same client to subscribe to some 
other) and enforce this on the broker side (in the broker logic)?

Any help would be greatly appreciated.

Best,
David