[zeromq-dev] ZMQPP and metadata in ZAP reply

David Jelenc david.jelenc at fri.uni-lj.si
Fri Apr 29 15:39:11 CEST 2016

According to http://rfc.zeromq.org/spec:27, the ZAP reply contains 
several fields, including the metadata filed that can be used to store 
additional data regarding the authenticating clients.

I’d like to use this filed to store some authorization data: the idea is 
that, using ZAP, my server queries an AAA server that either accepts or 
rejects the the connecting client. If the client is accepted, the AAA 
also provides a list of actions the accepted client is allowed to 
perform. I’d like to store this actions in the metadata field of the ZAP 

I’m using zmqpp C++ bindings, where the metadata is currently hardcoded 
to be empty 
However, this is easily addressed.

My main concern is now on the server side: where and how do I process 
this metadata?

The API is such that if the ZAP reply contains status code 200 and a OK 
message, the client is allowed to connect. However, I see no way for 
accessing the additional parts of the ZAP reply on my server.

I sense, this part has to be addressed in libzmq and not in zmqpp, but 
I’m not sure where.

Any help would be greatly appreciated.


More information about the zeromq-dev mailing list