base.py 文件源码

def serial_number(self, number):
        """
        Sets the certificate serial number.
        """
        if not isinstance(number, six.integer_types):
            raise TypeError('Serial number must be of integral type.')
        if self._serial_number is not None:
            raise ValueError('The serial number may only be set once.')
        if number < 0:
            raise ValueError('The serial number should be non-negative.')
        if utils.bit_length(number) > 160:  # As defined in RFC 5280
            raise ValueError('The serial number should not be more than 160 '
                             'bits.')
        return CertificateBuilder(
            self._issuer_name, self._subject_name,
            self._public_key, number, self._not_valid_before,
            self._not_valid_after, self._extensions
        )