libtinypoker has just two dependencies, GNU Transport Layer Security and GNU Scientific Library.

The next step is to get a copy of the libtinypoker source code. This can be done by checking out a fresh copy from the subversion repository or by downloading the latest release.

libtinypoker uses TLS to secure client/server communications. This is not a standard part of the Internet Poker Protocol, but it adds a layer of security that preventing players from snooping on each other with packet sniffers. See server setup for instructions on setting up a proxy server with stunnel that will allow unmodified legacy clients to connect.

For libtinypoker to work, it needs a server side certificate. You can obtain a certificate from a trusted certificate authority or you can create your own certificate authority and sign your own certificates. The example below demonstrates how to create your own certificate authority and sign your own certificates using the certtool program that comes with GNU TLS.

cn = Dummy Certificate Authority
ca
cert_signing_key

organization = Dummy Organization
cn = localhost
tls_www_server
encryption_key
signing_key
dns_name = localhost

 $ certtool --generate-privkey > ca-key.pem
 $ certtool --generate-privkey > key.pem
 $ certtool --generate-self-signed --load-privkey ca-key.pem \
       --template ca.tmpl --outfile ca.pem
 $ certtool --generate-certificate --load-privkey key.pem \
       --load-ca-certificate ca.pem --load-ca-privkey ca-key.pem \
       --template localhost.tmpl --outfile cert.pem

Several GNU TLS resources need to be allocated before network communications begin and deallocated after network connications end. Two functions are provided to accomplish this, ipp_init() and ipp_exit(). Additionally, the random number generator is allocated and freed in those functions. The one and only header file needed to use the API is tinypoker.h.

What follows is an example that simply initializes and cleans up after libtinypoker.

#include <tinypoker.h>

int main(int argc, char *argv[]) {
        ipp_init();

        ipp_exit();
        return 0;
}

Compiling a libtinypoker application is relatively simple. One simply needs to instruct the compiler to link against the library and GNU TLS.

 $ gcc -lpthread -ltinypoker -lgnutls -lgsl -lgslcblas -o test test.c

The protocol calls for a handshake to happen between the client and the server. During the handshake the client connects, the server notifies the client of the supported protocol version, the client response with a buy in request and the server responds with a welcome message.

This can be done manually with a connect, a read, a send and another read. Since the code is 25+ lines and since every client application will need to do this, libtinypoker provides a helper function (demonstrated below).

#include <tinypoker.h>

int main(int argc, char *argv[]) {
        ipp_socket *sock;

        ipp_init();

        sock = ipp_client_handshake("localhost", "ca.pem", "TEST", "ABC123", "500", NULL);
        if (!sock) {
                ipp_exit();
                return 1;
        }

        ipp_disconnect(sock);
        ipp_free_socket(sock);
        sock = NULL;

        ipp_exit();
        return 0;
}

Having access to the payload (text string) of every message that gets sent or recieved is useful for debugging. Each message could also be saved to a file for analysis and statistics gathering. Therefore, the send and read functions have a protocol logger callback. You can create your own logging function like the one below.

#include <tinypoker.h>

void protocol_logger(char *msg) {
        if (msg && msg[0]) {
                printf("%s\n", msg);
        }
}

int main(int argc, char *argv[]) {
        ipp_socket *sock;

        ipp_init();

        sock = ipp_client_handshake("localhost", "ca.pem", "TEST", "ABC123", "500", protocol_logger);
        if (!sock) {
                ipp_exit();
                return 1;
        }

        ipp_disconnect(sock);
        ipp_free_socket(sock);
        sock = NULL;

        ipp_exit();
        return 0;
}

This document is being written as tinypokerclient and tinypokerbot are being developed, so it is still very much a work in progress. If you want to go further, take a look at tinypoker.h; it is well commented and should give you and idea about the functions and structures available.