Authenticated Commands With MtGox's Streaming API

Question

I am using nodejs with socket.io-client to connect to the MtGox Streaming API described here: https://en.bitcoin.it/wiki/MtGox/API/Streaming#Authenticated_commands

The examples are written in php and I tried my best to convert them to JS but I keep getting a response from the server "Invalid call"

var sec_key_buffer = Buffer(secret_key, 'base64');
var hmac = crypto.createHmac('sha512', sec_key_buffer);
var nonce = Date.now() + "";
var id = crypto.createHash('md5').update(nonce).digest('hex');
var query = {
    "call": 'private/info',
    "id": id,
    "nonce": nonce
};
var body = JSON.stringify(query);
var sign = hmac.update(body).digest('binary');

// The 'api_key' field has already stripped of the '-' character
var callBody = new Buffer(api_key + sign + body).toString('base64');

// 'connection' is the socket.io connection to 'https://socketio.mtgox.com/mtgox'    
connection.json.send({
    "op": "call",
    "id": id,
    "call": callBody,
    "context": 'mtgox.com'
});

Any help would be appreciated.

Answer 1

Here's what seemed to work for me:

var io = require('socket.io-client');
var crypto = require('crypto');

var socket = io.connect('https://socketio.mtgox.com/mtgox');

var MTGOX_API_INFO = {
  key: '<YOUR_KEY>',
  secret: '<YOUR_SECRET>'
}

var MTGOX_CHANNELS = {
  trade: 'dbf1dee9-4f2e-4a08-8cb7-748919a71b21',
  depth: '24e67e0d-1cad-4cc0-9e7a-f8523ef460fe',
  ticker: 'd5f06780-30a8-4a48-a2f8-7ed181b4a13f'
}

// unsubscribe from depth and trade messages
socket.emit('message', {
  op: 'unsubscribe', 
  channel: MTGOX_CHANNELS.trade
});
socket.emit('message', {
  op: 'unsubscribe', 
  channel: MTGOX_CHANNELS.depth
});
socket.emit('message', {
  op: 'unsubscribe', 
  channel: MTGOX_CHANNELS.ticker
});


var getNonce = function() {
  return ((new Date()).getTime() * 1000).toString();
}

var nonce = getNonce();
var requestId = crypto.createHash('md5').update(nonce).digest('hex');
var query = {
  id: requestId,
  call: 'private/info',
  nonce: nonce
  // params: {},
  // item: 'BTC',
  // currency: 'USD'
};
var queryJSON = JSON.stringify(query);

var signedQuery = crypto.createHmac('sha512', new Buffer(MTGOX_API_INFO.secret, 'base64')).update(queryJSON).digest('binary');
var binKey = (new Buffer(MTGOX_API_INFO.key.replace(/-/g, ''), 'hex')).toString('binary');
var buffer = new Buffer(binKey + signedQuery + queryJSON, 'binary');
var call = buffer.toString('base64');

var command = {
  op: 'call',
  id: requestId,
  call: call,
  context: 'mtgox.com'
};

console.log("REQUEST:", command);

socket.emit('message', command);
socket.on('message', function(data) {
  console.log(data);
});

UPDATE: I've also abstracted it into a simple node module.