char *BUF_strndup(const char *str, size_t siz)
	{
	char *ret;

	if (str == NULL) return(NULL);

	ret=OPENSSL_malloc(siz+1);
	if (ret == NULL) 
		{
		BUFerr(BUF_F_BUF_STRNDUP,ERR_R_MALLOC_FAILURE);
		return(NULL);
		}
	BUF_strlcpy(ret,str,siz+1);
	return(ret);
	}