backend.py 文件源码

def _create_x509_extension(self, handlers, extension):
        if isinstance(extension.value, x509.UnrecognizedExtension):
            obj = _txt2obj_gc(self, extension.oid.dotted_string)
            value = _encode_asn1_str_gc(
                self, extension.value.value, len(extension.value.value)
            )
            return self._lib.X509_EXTENSION_create_by_OBJ(
                self._ffi.NULL,
                obj,
                1 if extension.critical else 0,
                value
            )
        else:
            try:
                encode = handlers[extension.oid]
            except KeyError:
                raise NotImplementedError(
                    'Extension not supported: {0}'.format(extension.oid)
                )

            ext_struct = encode(self, extension.value)
            nid = self._lib.OBJ_txt2nid(
                extension.oid.dotted_string.encode("ascii")
            )
            backend.openssl_assert(nid != self._lib.NID_undef)
            return self._lib.X509V3_EXT_i2d(
                nid, 1 if extension.critical else 0, ext_struct
            )