From e7cbe8ed85bb1a0660ced1dee4b34c8cd2bfb9e3 Mon Sep 17 00:00:00 2001
From: Duc Nguyen <ductri.nguyen@sandboxquantum.com>
Date: Fri, 8 Sep 2023 16:18:06 -0400
Subject: [PATCH] add a check so we don't overwrite data

---
 src/sig_stfl/xmss/sig_stfl_xmss_secret_key_functions.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/sig_stfl/xmss/sig_stfl_xmss_secret_key_functions.c b/src/sig_stfl/xmss/sig_stfl_xmss_secret_key_functions.c
index d4dfb4fd1c..de7c6fac54 100644
--- a/src/sig_stfl/xmss/sig_stfl_xmss_secret_key_functions.c
+++ b/src/sig_stfl/xmss/sig_stfl_xmss_secret_key_functions.c
@@ -30,6 +30,12 @@ OQS_STATUS OQS_SECRET_KEY_XMSS_deserialize_key(OQS_SIG_STFL_SECRET_KEY *sk, cons
 		return OQS_ERROR;
 	}
 
+	if (sk->secret_key_data) {
+		// Key data already present
+		// We dont want to trample over data
+		return OQS_ERROR;
+	}
+
 	memcpy(sk->secret_key_data, sk_buf, sk_len);
 
 	return OQS_SUCCESS;