'Create the authentication token.
Creates the authentication token to use in the authentication header
return authentication header (Base64(username:password:random no)).
:returns: Authentication Header
:raises BrocadeZoningHttpException:'

def create_auth_token(self):

    try:
        response = self.connect(zone_constant.GET_METHOD, zone_constant.SECINFO_PAGE)
        parsed_data = self.get_parsed_data(response, zone_constant.SECINFO_BEGIN, zone_constant.SECINFO_END)
        self.random_no = self.get_nvp_value(parsed_data, zone_constant.RANDOM)
        auth_string = ((((self.switch_user + ':') + self.switch_pwd) + ':') + self.random_no)
        auth_token = base64.encode_as_text(auth_string).strip()
        auth_header = (zone_constant.AUTH_STRING + auth_token)
    except Exception as e:
        msg = (_('Error    while    creating    authentication    token:    %s') % six.text_type(e))
        LOG.error(msg)
        raise exception.BrocadeZoningHttpException(reason=msg)
    return auth_header
