code: function base64(text, operation) {
    operation = operation || 'encode';
    if (operation === 'decode') {
      return (new Buffer(text, 'base64')).toString();
    } else {
      return (new Buffer(text)).toString('base64');
    }
  }
docs: Base64 encode and decode
  @function $crypt~base64
  @param {string} string  - String to encode or decode
  @param {string} [operation=encode] - Operation to perform. Allowed values: 'encode', 'decode'
  @returns {string} - Base64 encoded or decoded value
  @example
  // Encode binary text
  $crypt.base64('hello');
  // => 'aGVsbG8='
  @example
  // Decode base64 encoded text
  $crypt.base64('aGVsbG8=', 'decode');
  // => 'hello'