SecureCookieSessionInterface

The default session interface that stores sessions in signed cookies through the :mod:itsdangerous module.

Attributes

Attribute	Type	Description
salt	string = "cookie-session"	the salt that should be applied on top of the secret key for the signing of cookie based sessions.
digest_method	callable = staticmethod(_lazy_sha1)	the hash function to use for the signature.
key_derivation	string = "hmac"	the name of the itsdangerous supported key derivation.
serializer	object = session_json_serializer	A python serializer for the payload.
session_class	type = SecureCookieSession	The class used to create session objects, which defaults to SecureCookieSession.

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Constructor

Signature

def SecureCookieSessionInterface() - > null

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Methods

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get_signing_serializer()

@classmethod
def get_signing_serializer(
    app: [Flask](../app/flask.md?sid=flask_app_flask)
) - > URLSafeTimedSerializer | null

Creates and returns a serializer used to sign and verify session cookies using the application's secret keys. It incorporates fallback keys from the application configuration to ensure session continuity during key rotation.

Parameters

Name	Type	Description
app	[Flask](../app/flask.md?sid=flask_app_flask)	The Flask application instance providing the secret keys and configuration for the serializer.

Returns

Type	Description
`URLSafeTimedSerializer	null`

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open_session()

@classmethod
def open_session(
    app: [Flask](../app/flask.md?sid=flask_app_flask),
    request: [Request](../wrappers/request.md?sid=flask_wrappers_request)
) - > SecureCookieSession | null

Retrieves the session data from a signed cookie in the incoming request. If the cookie is missing or the signature is invalid, it returns a new empty session object.

Parameters

Name	Type	Description
app	[Flask](../app/flask.md?sid=flask_app_flask)	The Flask application instance used to access session lifetime settings and the signing serializer.
request	[Request](../wrappers/request.md?sid=flask_wrappers_request)	The incoming request object containing the cookies to be parsed.

Returns

Type	Description
`SecureCookieSession	null`

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save_session()

@classmethod
def save_session(
    app: [Flask](../app/flask.md?sid=flask_app_flask),
    session: [SessionMixin](sessionmixin.md?sid=flask_sessions_sessionmixin),
    response: [Response](../wrappers/response.md?sid=flask_wrappers_response)
) - > null

Saves the session data back to a signed cookie in the response or deletes the cookie if the session has been emptied. It also manages the 'Vary: Cookie' header to ensure proper downstream caching behavior.

Parameters

Name	Type	Description
app	[Flask](../app/flask.md?sid=flask_app_flask)	The Flask application instance used to determine cookie attributes like domain, path, and security flags.
session	[SessionMixin](sessionmixin.md?sid=flask_sessions_sessionmixin)	The session object containing the data to be persisted or cleared.
response	[Response](../wrappers/response.md?sid=flask_wrappers_response)	The outgoing response object where the session cookie or deletion header will be set.

Returns

Type	Description
null	Nothing is returned; the response object is modified in-place.

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