The PSA specification defines multiple key locations (of type key_location_t) that specify the high-level behavior of the key. The default key location supported by all drivers is the the Primary Local Storage.

Other key locations may be supported by specific hardware accelerated ports. See the Port Layers section.

NOTE: Currently, the PSA reference implementation does not expose vendor-defined key locations. To expose NXP-defined key locations, please include the mcux_psa_defines.h header that is contained in the middleware/mbedtls3x/port/ folder.

Properly exposing vendor-defined key locations through the regular inclusion of psa/crypto.h is a work in progress.

This storage location is defined by PSA as PSA_KEY_LOCATION_LOCAL_STORAGE and is assigned the value of 0. Keys that are assigned this location are transparent, so readable in plain text.

Some drivers may define additional, driver-specific, locations that implement additional ways of handling opaque key material. Such driver-specific key locations will be documented in their respective port layer readmes.

Below is a list of supported port layers with links to their respective readmes.

• ELE_S200
• CAAM (to be added)
• Casper / Hashcrypt (to be added)
• DCP (to be added)
• ELA_CSEC (to be added)
• ELE_HSEB (to be added)
• ELE_S4XX (to be added)
• SGI (to be added)
• ELS_PKC (to be added)