yubioath-flutter/lib/oath/views/utils.dart
2022-07-06 15:22:15 +02:00

34 lines
1.0 KiB
Dart
Executable File

import 'dart:math';
import '../../widgets/utf8_utils.dart';
import '../models.dart';
import '../../core/models.dart';
/// Calculates the available space for issuer and account name.
///
/// Returns a [Pair] of the space available for the issuer and account name,
/// respectively, based on the current state of the credential.
Pair<int, int> getRemainingKeySpace(
{required OathType oathType,
required int period,
required String issuer,
required String name}) {
int remaining = 64; // The field is 64 bytes in total.
if (oathType == OathType.totp && period != defaultPeriod) {
// Non-standard TOTP periods are stored as part of this data, as a "D/"- prefix.
remaining -= '$period/'.length;
}
int issuerSpace = byteLength(issuer);
if (issuer.isNotEmpty) {
// Issuer is separated from name with a ":", if present.
issuerSpace += 1;
}
return Pair(
// Always reserve at least one character for name
remaining - 1 - max(byteLength(name), 1),
remaining - issuerSpace,
);
}