Update XMSS-SM3

XMSS is in developing, not fully tested

include/gmssl/hash256.h

@@ -0,0 +1,28 @@
+/*
+ *  Copyright 2014-2025 The GmSSL Project. All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the License); you may
+ *  not use this file except in compliance with the License.
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+#ifndef GMSSL_HASH256_H
+#define GMSSL_HASH256_H
+
+
+#include <stdint.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+typedef uint8_t hash256_t[32];
+
+
+#ifdef __cplusplus
+}
+#endif
+#endif