'What are the subject names of this certificate?
(If no version is specified, use the current version.)
:param int version: the desired version number
:returns: the subject names
:rtype: `list` of `str`
:raises .CertStorageError: if could not find cert file.'

def names(self, version=None):

    if (version is None):
        target = self.current_target('cert')
    else:
        target = self.version('cert', version)
    if (target is None):
        raise errors.CertStorageError('could    not    find    cert    file')
    with open(target) as f:
        return crypto_util.get_names_from_cert(f.read())
