Question: is there a way to view the client public key presented to server?

[fhtino]

I am new to NetMQ. I am playing with curve key-pairs and they work fine.
On the client side, I have to give the server public key and client public+secret.
On the server, is there a way to see/extract the public key presented by the client connecting to the server?
On the server I would like to have a list of allowed clients, so a list of public client keys allowed to connect .
It there a way to do that?