- void *EC_KEY_get_key_method_data(EC_KEY *key,
- void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *));
- void EC_KEY_insert_key_method_data(EC_KEY *key, void *data,
- void *(*dup_func)(void *), void (*free_func)(void *), void (*clear_free_func)(void *));