ssl-auto-ref-client

ssl-auto-ref-client

This folder contains a sample client that connects to the autoRef interface of the game-controller.

Protocol

The communication is established with a bidirectional TCP connection. Messages are encoded with Protocol Buffers. Each message is preceded by an uvarint containing the message size in bytes, see https://cwiki.apache.org/confluence/display/GEODE/Delimiting+Protobuf+Messages for details.

The .proto files can be found here.

The default port is 10007. The IP to connect to can be determined using the multicast referee messages.

Connection Sequence

The connection is described in the following sequence diagram:

Source to generate the diagram: communication_autoRef.txt

Connection stability

Clients should deal with connection losts (reconnect). The game-controller may be restarted due to various reasons like crashes or other technical issues. AutoRefs should reconnect automatically after a connection lost without human interaction.

Secure Connection

The connection can optionally be secured by signing each request using a RSA key.

The private key is used on the client side to sign the complete message, excluding the signature itself. The public key must be provided to the game-controller. By default, the game-controller searches for public keys in config/trusted_keys/auto_ref with the pattern <identifier>.pub.pem.

The genKey.sh script can be used to generate a new pair of public and private key.

The controller sends a token with each reply. It must be included in the next request, when using the signature. The token is required to avoid replay attacks.

If a public key is present for the identifier provided during registration, a signature is required. Else, the signature is ignored. The controller reply indicates, if the last request could be verified.

Sample client

The sample client, that is included in this folder, can be used to test the connection. It can be run with

go run cmd/ssl-auto-ref-client/main.go

Pass it the -h parameter to get the available options.