var activedirectory = require('activedirectory');
var config = {
  url: 'ldap://example.com',                      // AD url
  baseDN: 'cn=users,dc=domain,dc=example,dc=com'  // ldap search query string
  username: 'user',                               // username for connection (can be empty, depending on AD configuration)
  passsword: 'pass'                               // pass for user (can be empty, depending on user configuration)
};

var ad = new ActiveDirectory(config);

var username = 'AUTH_USER';                       // User to be authenticated
var pass = 'AUTH_PASS';                           // Password for the user 

ad.authenticate(username, password, function(err, auth) {
  if(err) {
    console.log('ERROR: ' + JSON.stringofy(err));
    return;
  }
  
  if(auth) {
    console.log('Authenticated!');
  } else {
    console.log('Authentication failed');
  }
});