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The IdP provides a number of general-purpose storage facilities that can be used by core subsystems like session management and consent. various features like sessions, consent, replay detection, CAS ticket storage, and many others, including various features provided by additional plugins.
Broadly speaking, there are two kinds of storage plugins: client-side and server-side. Client-side plugins have the advantage of requiring no additional software or configuration and make clustering very robust and simple, but they only support a subset of use cases well since the data lives only in a single user agent. Server-side plugins support all use cases (aside from the simple case of storing data in memory) support all use cases, but require additional software and configuration, and usually create additional points of failure in a clustered deployment.
Where possible, the project recommends using client-side storage whereever possible/acceptable, and in particular for session storage, which uses that approach now by default. In other cases, we suggest consideration of in-memory storage where the use case allows, or if the feature supports a more advanced approach that doesn’t require storage at all. In most cases, we default to not requiring storage when possible (e.g., CAS ticket encoding, SAML transient NameID construction, others).
The most common use case in the core software requiring persistent server-side storage, and thus some additional infrastructure, is probably consent (assuming that storing consent per-browser is not desirable).
When clustering, you should obviously take a look at the Clustering topic for a more holistic discussion of that use case. You may also wish to review the SameSite topic, as it may have implications for your storage options and/or the need to address SameSite based on your chosen options.
The IdP ships with 3 preconfigured org.opensaml.storage.StorageService beans:
shibboleth.ClientSessionStorageService (of type ClientStorageService)
Stores data in a browser session cookie or HTML local storage
shibboleth.ClientPersistentStorageService (of type ClientStorageService)
Stores data in a long-lived browser cookie or HTML local storage
shibboleth.StorageService (of type MemoryStorageService)
Stores data in server memory, does not survive restarts and is not replicated across a cluster
There are is an additional storage service plugins implementation included in the software (JPA, memcached), and at least one plugin available for JDBC, but they are not predefined. Using them requires defining beans yourself and setting various properties to point to them.
By default, the shibboleth.ClientSessionStorageService bean, which stores data in the client, is used to store IdP session data, but that can be modified via the idp.properties file:
Example changing IdP session storage to in-memory for non-clustered use:
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idp.session.StorageService = shibboleth.StorageService |
There are additional properties that can be used to change how other data is stored on a per-use case basis, but note that some components can't (or usually shouldn’t) rely on client-side storage options, and more specific documentation should will address that. This topic is the overview of how to configure storage options, but doesn’t speak to handling specific use cases.
Reference
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The ClientStorageService is an advanced, and highly strongly recommended, option that includes support for HTML Local Storage along with cookies as a fallback or alternative. It is the default mechanism for storage of sessions that allow for SSO and we recommend it for that purpose to the exclusion of the server-side options. Local Storage support is enabled by default for new installationsinstallation, but note that there are visual impacts from the use of the feature and it requires JavaScript be enabled, because reading and writing to the client requires an explicit page be rendered. Controlling this When JavaScript is enabled, the additional page appears quickly as a short-lived interstitial with a message about the loading or saving of the data to the client. In practice, it is has no material impact on the user experience and the loading page only appears when a new session with the servlet container is created. Controlling the Local Storage feature is handled by the idp.storage.htmlLocalStorage property. No additional configuration is required, but you may want to change the look and feel of the templates that are displayed to the client while data is being read or written. These pages don't require any user interaction as long as JavaScript is enabled, but they tend to be visible at least briefly, particularly the first time through. They're somewhat similar to the templates displayed when SAML messages are handed off to the browser. Much of that look is obviously controlled by style sheets and message properties, but the "visible" portions are in views/client-storage (to avoid losing your changes on upgrades). As to why you would use Local Storage vs. just allowing use of cookies with this storage implementation, there are really two main reasons:
The main reason for this feature is to enable the IdP's session manager to track and index the sessions created with SPs, and that information does not fit reliably in a cookie. That makes the single-logout feature unusable with client-side sessions unless Local Storage is enabled, since the IdP doesn't know what SPs to communicate with. Enabling the Local Storage feature is necessary but not sufficient to allow at least some form of single logout to work without moving session storage to the server. You also will need to ensure a couple of additional session management properties (idp.session.trackSPSessions and idp.session.secondaryServiceIndex) are enabled, and they are also on by default in new installs. There are two properties because the latter is more a SAML-specific need that may not extend to other protocols in the future. The consent feature is very limited when cookies are used because the number of records it can store is extremely small. If Local Storage is available, that limit is essentially ignored. If you're comfortable with tracking consent per-device, this is a much more practical simpler way to deploy it at most sites than with a database. Of course, many deployers are not comfortable with per-device consent, but those same deployers may become a lot more comfortable with it after enough database connection failures due to the nearly universally poor quality of JDBC networking code. |
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Requirements: memcached v1.4.14 or later The memcached-based storage service is based on the spymemcached library, which has a number of features for HA deployments:
The failover facility merits further discussion. Failover is enabled by specifying multiple memcached hosts and Bear in mind that different storage use cases have different failover properties. While the replay cache would be similarly unimpacted, the artifact map failing to retrieve a previously stored artifact mapping would result in a failed login to the service to which the artifact was sent. The following architecture is strongly recommended suggested for HA deployments using memcache: Thus every IdP node runs a memcached service and the Java process running the IdP software connects to every memcached service. The following configuration example assumes the recommended architecture above and should be placed in conf/global.xml . MemcachedStorageService Configuration
Once a MemcachedStorageService bean has been defined as above, it can be used with subsystems that require a StorageService component. The following configuration snippet from conf/idp.properties indicates how to use memcached for session storage. Memcached for IdP Sessions
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