nugget: Update nugget command usage

In order to support secure PSK provision for new platform, try to re-use
NUGGET_PARAM_GSA_KEY_PROVISION for secure PSK handshaking.

Bug: 295401370
Change-Id: I657f60a71d7324044ec21bcfd3be010941703472

1 files changed, 20 insertions, 3 deletions

diff --git a/nugget/include/app_nugget.h b/nugget/include/app_nugget.h
index 8852b18..49ca2de 100644
--- a/nugget/include/app_nugget.h
+++ b/nugget/include/app_nugget.h
@@ -462,10 +462,27 @@ struct gsa_gsc_psk_persist_storage {
 /*
  * GSA key provision command
  *
- * @param args         gsa unique public key
+ * We use the same command id to support multiple GSA-GSC PSK
+ * provision handshaking. List possible args and reply usage by
+ * each case.
+ *
+ * Non-secure PSK provision case:
+ * @param args         GSA-GSC PSK (plaintext)
  * @param arg_len      32
- * @param reply        gsc public key + sha256(pre-shared key)
- * @param reply_len    64 + 32
+ * @param reply        GSA-GSC PSK (plaintext)
+ * @param reply_len    32
+ *
+ * Ephemeral ec key handshaking case:
+ * @param args         GSA public key
+ * @param arg_len      64
+ * @param reply        GSC public key + signature
+ * @param reply_len    64 + 64
+ *
+ * Secure PSK provision case:
+ * @param args         encrypted GSA-GSC PSK (nonce + PSK + tag)
+ * @param arg_len      12 + 32 + 16
+ * @param reply        <none>
+ * @param reply_len    0
  */
 
 /**