base.py 文件源码

def add_extension(self, extension, critical):
        if not isinstance(extension, ExtensionType):
            raise TypeError("extension must be an ExtensionType")

        extension = Extension(extension.oid, critical, extension)

        # TODO: This is quadratic in the number of extensions
        for e in self._extensions:
            if e.oid == extension.oid:
                raise ValueError('This extension has already been set.')
        return RevokedCertificateBuilder(
            self._serial_number, self._revocation_date,
            self._extensions + [extension]
        )