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/scripts/config.pl b/scripts/config.pl
index 2e4ac3b..69c6d5f 100755
--- a/scripts/config.pl
+++ b/scripts/config.pl
@@ -116,6 +116,8 @@
MBEDTLS_MEMORY_BUFFER_ALLOC_C
MBEDTLS_PLATFORM_TIME_ALT
MBEDTLS_PLATFORM_FPRINTF_ALT
+MBEDTLS_PSA_CRYPTO_STORAGE_C
+MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C
);
# Things that should be enabled in "full" even if they match @excluded