yubioath-flutter/lib/fido/views/pin_dialog.dart

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../app/models.dart';
import '../../app/state.dart';
import '../../app/views/responsive_dialog.dart';
import '../models.dart';
import '../state.dart';

class FidoPinDialog extends ConsumerStatefulWidget {
  final DevicePath devicePath;
  final FidoState state;
  const FidoPinDialog(this.devicePath, this.state, {Key? key})
      : super(key: key);

  @override
  ConsumerState<ConsumerStatefulWidget> createState() => _FidoPinDialogState();
}

class _FidoPinDialogState extends ConsumerState<FidoPinDialog> {
  String _currentPin = '';
  String _newPin = '';
  String _confirmPin = '';
  String? _currentPinError;
  String? _newPinError;

  @override
  Widget build(BuildContext context) {
    // If current device changes, we need to pop back to the main Page.
    ref.listen<DeviceNode?>(currentDeviceProvider, (previous, next) {
      Navigator.of(context).pop();
    });

    final minPinLength = widget.state.minPinLength;
    final hasPin = widget.state.hasPin;

    return ResponsiveDialog(
      title: Text(hasPin ? 'Change PIN' : 'Set PIN'),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          if (hasPin) ...[
            Text(
              'Current PIN',
              style: Theme.of(context).textTheme.headline6,
            ),
            TextFormField(
              initialValue: _currentPin,
              autofocus: true,
              obscureText: true,
              decoration: InputDecoration(
                border: const OutlineInputBorder(),
                labelText: 'Current PIN',
                errorText: _currentPinError,
              ),
              onChanged: (value) {
                setState(() {
                  _currentPin = value;
                });
              },
            ),
          ],
          Text(
            'New PIN',
            style: Theme.of(context).textTheme.headline6,
          ),
          TextFormField(
            initialValue: _newPin,
            autofocus: !hasPin,
            obscureText: true,
            decoration: InputDecoration(
              border: const OutlineInputBorder(),
              labelText: 'New password',
              enabled: !hasPin || _currentPin.isNotEmpty,
              errorText: _newPinError,
            ),
            onChanged: (value) {
              setState(() {
                _newPin = value;
              });
            },
          ),
          TextFormField(
            initialValue: _confirmPin,
            obscureText: true,
            decoration: InputDecoration(
              border: const OutlineInputBorder(),
              labelText: 'Confirm password',
              enabled: _newPin.isNotEmpty,
            ),
            onChanged: (value) {
              setState(() {
                _confirmPin = value;
              });
            },
          ),
        ]
            .map((e) => Padding(
                  padding: const EdgeInsets.symmetric(vertical: 8.0),
                  child: e,
                ))
            .toList(),
      ),
      actions: [
        TextButton(
          child: const Text('Save'),
          onPressed: _newPin.isNotEmpty &&
                  _newPin == _confirmPin &&
                  (!hasPin || _currentPin.isNotEmpty)
              ? () async {
                  final oldPin = _currentPin.isNotEmpty ? _currentPin : null;
                  if (_newPin.length < minPinLength) {
                    setState(() {
                      _newPinError =
                          'New PIN must be at least $minPinLength characters';
                    });
                    return;
                  }
                  final result = await ref
                      .read(fidoStateProvider(widget.devicePath).notifier)
                      .setPin(_newPin, oldPin: oldPin);
                  result.when(success: () {
                    Navigator.of(context).pop(true);
                    ScaffoldMessenger.of(context).showSnackBar(
                      const SnackBar(
                        content: Text('PIN set'),
                        duration: Duration(seconds: 2),
                      ),
                    );
                  }, failed: (retries, authBlocked) {
                    setState(() {
                      if (authBlocked) {
                        _currentPinError =
                            'PIN has been blocked until the YubiKey is removed and reinserted';
                      } else {
                        _currentPinError =
                            'Wrong PIN ($retries tries remaining)';
                      }
                    });
                  });
                }
              : null,
        ),
      ],
    );
  }
}