Sample Votifier Protocol v2 clients

votifier2.js

var crypto = require('crypto');
var net = require('net');

function createMessage(header, vote) {
    var data = header.split(' ');

    if (data.length != 3) {
        throw new Error("Not a Votifier v2 protocol server");
    }

    vote['challenge'] = data[2].substring(0, data[2].length - 1);
    var voteAsJson = JSON.stringify(vote);
    var digest = crypto.createHmac('sha256', options.token);
    digest.update(voteAsJson);
    var sig = digest.digest('base64');

    var message = JSON.stringify({payload: JSON.stringify(vote), signature: sig});
    var messageBuffer = new Buffer(message.length + 4);
    messageBuffer.writeUInt16BE(0x733a);
    messageBuffer.writeUInt16BE(message.length, 2);
    messageBuffer.write(message, 4);
    return messageBuffer;
}

module.exports = exports = function vote(options, cb) {
    if (!options.host || !options.port || !options.token || !options.vote) {
        return cb(new Error("missing host, port, token, or vote in 'server'"));
    }
    var vote = options.vote;
    if (!vote.username || !vote.address || !vote.timestamp || !vote.serviceName) {
        return cb(new Error("missing username, address, timestamp, or serviceName in 'vote'"));
    }

    var socket = net.createConnection(options.port, options.host);
    socket.once('data', function (buf) {
        var returnError = function () {
            cb(new Error('Unexpected error'));
        };
        socket.once('end', returnError);
        socket.write(createMessage(buf.toString(), vote));
        socket.once('data', function (respBuf) {
            var resp = JSON.parse(respBuf.toString());
            socket.removeListener('end', returnError);
            socket.end();
            if (resp.status == 'error') {
                cb(new Error(resp.cause + ': ' + resp.errorMessage));
            } else {
                cb(null);
            }
        });
    });
};

votifier2.py

import socket
import struct
import json
import time
import base64
import argparse
import sys
import hmac
import hashlib

def send(server, vote, token, debug=False):
  sock = socket.create_connection(server)
  header = sock.recv(40)

  vote["challenge"] = header.split(" ")[2][:-1]
  res = json.dumps(vote)
  signature = base64.b64encode(hmac.new(token, res, hashlib.sha256).digest())

  payload = {"signature": signature, "payload": res}
  res2 = json.dumps(payload)

  if debug:
    print("Sending: " + res2 + " (length: " + str(len(res2)) + ")")

  amt = struct.pack('>H', len(res2))
  magic = struct.pack('>H', 0x733A)
  sock.send(magic + amt + res2)

  result = sock.recv(512)
  return json.loads(result)

if __name__ == "__main__":
  parser = argparse.ArgumentParser()
  parser.add_argument("-s", "--service-name", help="specify the service name to use when sending the vote (default: TestService)", default="TestService")
  parser.add_argument("-t", "--token", help="specify the server's token", required=True)
  parser.add_argument("-d", "--timestamp", help="specify the timestamp")
  parser.add_argument("-u", "--username", help="specify a custom username (default: VotifierUser)", default="VotifierUser")
  parser.add_argument("server", help="the backend Votifier server")
  args = parser.parse_args()

  server_parts = args.server.split(":")
  if len(server_parts) != 2:
    print "invalid server:port"
    sys.exit(1)

  server = (server_parts[0], int(server_parts[1]))
  if args.timestamp:
    timestamp = int(args.timestamp)
  else:
    timestamp = int(time.time()*10)

  response = send(server, {'username': args.username, 'address': '127.0.0.1', 'timestamp': timestamp, 'serviceName': args.service_name}, args.token, debug=True)
  print(str(response))