Merge pull request #3995 from stevew817/feature/psa_configurable_static_ram_usage

Allow tweaking PSA_KEY_SLOT_COUNT

include/mbedtls/config.h

@@ -3687,6 +3687,17 @@
  */
 //#define MBEDTLS_PSA_HMAC_DRBG_MD_TYPE MBEDTLS_MD_SHA256
 
+/** \def MBEDTLS_PSA_KEY_SLOT_COUNT
+ * Restrict the PSA library to supporting a maximum amount of simultaneously
+ * loaded keys. A loaded key is a key stored by the PSA Crypto core as a
+ * volatile key, or a persistent key which is loaded temporarily by the
+ * library as part of a crypto operation in flight.
+ *
+ * If this option is unset, the library will fall back to a default value of
+ * 32 keys.
+ */
+//#define MBEDTLS_PSA_KEY_SLOT_COUNT 32
+
 /* SSL Cache options */
 //#define MBEDTLS_SSL_CACHE_DEFAULT_TIMEOUT       86400 /**< 1 day  */
 //#define MBEDTLS_SSL_CACHE_DEFAULT_MAX_ENTRIES      50 /**< Maximum entries in cache */

include/psa/crypto_extra.h

@@ -39,6 +39,10 @@ extern "C" {
 /* UID for secure storage seed */
 #define PSA_CRYPTO_ITS_RANDOM_SEED_UID 0xFFFFFF52
 
+/* See config.h for definition */
+#if !defined(MBEDTLS_PSA_KEY_SLOT_COUNT)
+#define MBEDTLS_PSA_KEY_SLOT_COUNT 32
+#endif
 
 /** \addtogroup attributes
  * @{