psa: Add storage implementation for files
Add new functions, psa_load_persistent_key(),
psa_free_persistent_key_data(), and psa_save_persistent_key(), for
managing persistent keys. These functions load to or save from our
internal representation of key slots. Serialization is a concern of the
storage backend implementation and doesn't abstraction-leak into the
lifetime management code.
An initial implementation for files is provided. Additional storage
backends can implement this interface for other storage types.
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index cd256c3..2190ac5 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -2617,6 +2617,31 @@
#define MBEDTLS_PSA_CRYPTO_C
/**
+ * \def MBEDTLS_PSA_CRYPTO_STORAGE_C
+ *
+ * Enable the Platform Security Architecture persistent key storage.
+ *
+ * Module: library/psa_crypto_storage.c
+ *
+ * Requires: MBEDTLS_PSA_CRYPTO_C, MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C
+ *
+ */
+#define MBEDTLS_PSA_CRYPTO_STORAGE_C
+
+/**
+ * \def MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C
+ *
+ * Enable persistent key storage over files for the
+ * Platform Security Architecture cryptography API.
+ *
+ * Module: library/psa_crypto_storage_file.c
+ *
+ * Requires: MBEDTLS_PSA_CRYPTO_C, MBEDTLS_FS_IO
+ *
+ */
+#define MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C
+
+/**
* \def MBEDTLS_RIPEMD160_C
*
* Enable the RIPEMD-160 hash algorithm.