const char *get_gost_engine_param(int param) 
	{
	char *tmp;
	if (param <0 || param >GOST_PARAM_MAX) return NULL;
	if (gost_params[param]!=NULL) 
		{
		return gost_params[param];
		}
	tmp = getenv(gost_envnames[param]);
	if (tmp) 
		{
		if (gost_params[param]) OPENSSL_free(gost_params[param]);
		gost_params[param] = BUF_strdup(tmp);
		return gost_params[param];
		}	
	return NULL;
	}