Method get_signing_serializer

src/flask/sessions.py:303–321

(self, app: Flask)

    session_class = SecureCookieSession

    def get_signing_serializer(self, app: Flask) -> URLSafeTimedSerializer | None:
        if not app.secret_key:
            return None

        keys: list[str | bytes] = []

        if fallbacks := app.config["SECRET_KEY_FALLBACKS"]:
            keys.extend(fallbacks)

        keys.append(app.secret_key)  # itsdangerous expects current key at top
        return URLSafeTimedSerializer(
            keys,  # type: ignore[arg-type]
            salt=self.salt,
            serializer=self.serializer,
            signer_kwargs={
                "key_derivation": self.key_derivation,
                "digest_method": self.digest_method,
            },
        )

    def open_session(self, app: Flask, request: Request) -> SecureCookieSession | None:
        s = self.get_signing_serializer(app)