fn touch_of(flag: Result<Option<UserInteractionFlag>, Error>) -> TouchExpand description
What a key’s user interaction flag says of its touch (DO D6 for signing, D7 for decrypting, D8 for authenticating: its first byte, the touch policy). A card without the flag asks for none; a flag that does not read is a touch maybe asked: said “If your key asks for a touch…”, a wrong guess costing nothing.