get_device_fingerprint.js

function (user, context, callback) {

  var deviceFingerPrint = getDeviceFingerPrint();
  user.app_metadata = user.app_metadata || {};
    
  if (user.app_metadata.lastLoginDeviceFingerPrint !== deviceFingerPrint) {

    user.app_metadata.lastLoginDeviceFingerPrint = deviceFingerPrint;

    context.multifactor = {
      allowRememberBrowser: false,
      provider: 'guardian'
    };
    
    auth0.users.updateAppMetadata(user.user_id, user.app_metadata)
    .then( function() {
      callback(null, user, context);
    })
    .catch( function(err) {
      callback(err);
    }); 
  } else {
    callback(null, user, context);
  }

  function getDeviceFingerPrint() {

    var shasum = crypto.createHash('sha1');
    shasum.update(context.request.userAgent);
    shasum.update(context.request.ip);
    return shasum.digest('hex');

  }
}