connot find client.user

[expandboard]

when use Ponte as embedded in nodejs code and i want to authorize for publishing, client.user is not found in client object while publish payload in MQTT.

var authorizePublish = function(client, topic, payload, callback) {
        callback(null, client.user == topic.split('/')[1]);
    } 

client.id is Ok but about client.user it is not included and it's undefined.

you can find whole code below;

       const debug = require('debug')('iok-express:ponte');
       const ponte = require('ponte');
       var config = require('../config/ponte.js');
       var mongoose = require('mongoose');
       var Thing = require("../models/thing");

        // Accepts the connection if the username and password are valid
    var authenticate = function (client, username, password, callback) {
        Thing.findOne({clientid: client.id}, function(err, things) {
            if (err) {
                console.log('Quering thing failed.');
                console.log(err);
                callback(null, false);
                return;
            }
            if (!things) {
                console.log("ClientID Not found, Client ID:" + client.id);
                callback(null, false);
                return;
            }  
            if (username == things.config.username && password == things.config.password)   {
                console.log('Successful MQTT credintial. Client ID:' + client.id);
                callback(null, true);
                return;
            }
            else {
                console.log('Unsuccessful MQTT credintial. Client ID:' + client.id + '  ,Username:' + username + '  ,Password:' + password);
                callback(null, false);  
            }
        });
    }

    var authorizePublish = function(client, topic, payload, callback) {
        callback(null, client.id == topic.split('/')[1]);
    }

    var authorizeSubscribe = function(client, topic, callback) {
        callback(null, client.id == topic.split('/')[1]);
    }

    config.mqtt.authenticate = authenticate;
    config.mqtt.authorizePublish = authorizePublish;
    config.mqtt.authorizeSubscribe = authorizeSubscribe;

    var server = ponte(config);

    server.on("updated", function(resource, buffer) {
        console.log("Resource Updated", resource, buffer);
    });