psa_key_lifetime_t

Encoding of key lifetimes. The lifetime of a key indicates where it is stored and what system actions may create and destroy it. Lifetime values have the following structure: - Bits 0-7 (#PSA_KEY_LIFETIME_GET_PERSISTENCE(\c lifetime)): persistence level. This value indicates what device management actions can cause it to be destroyed. In particular, it indicates whether the key is _volatile_ or _persistent_. See ::psa_key_persistence_t for more information. - Bits 8-31 (#PSA_KEY_LIFETIME_GET_LOCATION(\c lifetime)): location indicator. This value indicates which part of the system has access to the key material and can perform operations using the key. See ::psa_key_location_t for more information. Volatile keys are automatically destroyed when the application instance terminates or on a power reset of the device. Persistent keys are preserved until the application explicitly destroys them or until an integration-specific device management event occurs (for example, a factory reset). Persistent keys have a key identifier of type #mbedtls_svc_key_id_t. This identifier remains valid throughout the lifetime of the key, even if the application instance that created the key terminates. The application can call psa_open_key() to open a persistent key that it created previously. The default lifetime of a key is #PSA_KEY_LIFETIME_VOLATILE. The lifetime #PSA_KEY_LIFETIME_PERSISTENT is supported if persistent storage is available. Other lifetime values may be supported depending on the library configuration. Values of this type are generally constructed by macros called `PSA_KEY_LIFETIME_xxx`.