ra, ok := r.(io.ReaderAt)
	if !ok {
		return nil, codesign.CodeSigCmd{}, false
	}
	f, err := macho.NewFile(ra)
	if err != nil {
		return nil, codesign.CodeSigCmd{}, false
	}
	cmd, ok := codesign.FindCodeSigCmd(f)
	return f, cmd, ok

	Cmd      uint32 // LC_CODE_SIGNATURE
	Cmdsize  uint32 // sizeof this command (16)
	Dataoff  uint32 // file offset of data in __LINKEDIT segment
	Datasize uint32 // file size of data in __LINKEDIT segment
}

func FindCodeSigCmd(f *macho.File) (CodeSigCmd, bool) {
	get32 := f.ByteOrder.Uint32
	for _, l := range f.Loads {
		data := l.Raw()
		cmd := get32(data)
		if cmd == LC_CODE_SIGNATURE {
			return CodeSigCmd{
				cmd,