code: func parseAuthorizedKey(in []byte) (out PublicKey, comment string, err error) {
  	in = bytes.TrimSpace(in)
  
  	i := bytes.IndexAny(in, " \t")
  	if i == -1 {
  		i = len(in)
  	}
  	base64Key := in[:i]
  
  	key := make([]byte, base64.StdEncoding.DecodedLen(len(base64Key)))
  	n, err := base64.StdEncoding.Decode(key, base64Key)
  	if err != nil {
  		return nil, "", err
  	}
  	key = key[:n]
  	out, err = ParsePublicKey(key)
  	if err != nil {
  		return nil, "", err
  	}
  	comment = string(bytes.TrimSpace(in[i:]))
  	return out, comment, nil
  }
docs: // parseAuthorizedKey parses a public key in OpenSSH authorized_keys format
  // (see sshd(8) manual page) once the options and key type fields have been
  // removed.