If PMK and PTK are not set do not store keys to NVM

On border router do not allocate new supplicant data to NVM if both
PTK and PMK are not set.

source/6LoWPAN/ws/ws_pae_key_storage.c

@@ -360,7 +360,17 @@ int8_t ws_pae_key_storage_supp_write(const void *instance, supp_entry_t *pae_sup
     uint8_t *eui_64 = pae_supp->addr.eui_64;
 
     key_storage_array_t *key_storage_array;
-    sec_prot_keys_storage_t *key_storage = ws_pae_key_storage_get(instance, eui_64, &key_storage_array, true);
+    // Check if entry exists
+    sec_prot_keys_storage_t *key_storage = ws_pae_key_storage_get(instance, eui_64, &key_storage_array, false);
+    if (key_storage == NULL) {
+        // Do not allocate new storage if PMK and PTK are not set
+        if (!pae_supp->sec_keys.pmk_set && !pae_supp->sec_keys.ptk_set) {
+            tr_info("KeyS PMK and PTK not set, skip storing, eui64: %s", tr_array(eui_64, 8));
+            return -1;
+        }
+        // Allocate new empty entry
+        key_storage = ws_pae_key_storage_get(instance, eui_64, &key_storage_array, true);
+    }
 
     // If cannot find existing or empty storage and there is room for storages tries to allocate more storage
     if (key_storage == NULL && key_storage_params.storages_empty > 0) {