Possibility to mirror Sec-WebSocket-Protocols

[andrew-guz]

Hello.

We are using Sec-WebSocket-Protocols to send important data, that is not constant. So we can't predict subprotocol on server side.
From the other hand, we have to send something back, otherwise Browsers will not work correctly.

So, we suggest the next solution: add a possibility to return exactly the same subprotocol that was received.

[gittiver]

We are using Sec-WebSocket-Protocols to send important data, that is not constant. So we can't predict subprotocol on server side. From the other hand, we have to send something back, otherwise Browsers will not work correctly.

We can add this to Crow, but with this few informations it sounds like a strange design. You should think about if it maybe opens an attack vector or something like this.

[andrew-guz]

We are using Sec-WebSocket-Protocols to send important data, that is not constant. So we can't predict subprotocol on server side. From the other hand, we have to send something back, otherwise Browsers will not work correctly.

We can add this to Crow, but with this few informations it sounds like a strange design. You should think about if it maybe opens an attack vector or something like this.

We are using Sec-WebSocket-Protocols to send some information about client. And this data will be different for different clients. We want to get this info during onAccept, and reject, depending on this information if needed.
Since we have to send something back (https://datatracker.ietf.org/doc/html/rfc6455#section-11.3.4) this was the easiest solution for us.