def get_subject_without_validation(jwt_bu64):
    """Extract subject from the JWT without validating the JWT.

    - The extracted subject cannot be trusted for authn or authz.

    Args:
      jwt_bu64: bytes
        JWT, encoded using a a URL safe flavor of Base64.

    Returns:
      str: The subject contained in the JWT.

    """
    try:
        jwt_dict = get_jwt_dict(jwt_bu64)
    except JwtException as e:
        return log_jwt_bu64_info(logging.error, str(e), jwt_bu64)
    try:
        return jwt_dict['sub']
    except LookupError:
        log_jwt_dict_info(logging.error, 'Missing "sub" key', jwt_dict)