Refactor FIDO PIN handling.

lib/desktop/fido/state.dart

@@ -46,17 +46,11 @@ class _DesktopFidoStateNotifier extends FidoStateNotifier {
   final RpcNodeSession _session;
   _DesktopFidoStateNotifier(this._session) : super();
 
-  Future<void> refresh() async {
-    try {
+  Future<void> refresh() => updateState(() async {
         final result = await _session.command('get');
         _log.config('application status', jsonEncode(result));
-      final fidoState = FidoState.fromJson(result['data']);
-      setState(fidoState);
-    } catch (error) {
-      _log.severe('Unable to update FIDO state', jsonEncode(error));
-      setFailure('Failed to update FIDO');
-    }
-  }
+        return FidoState.fromJson(result['data']);
+      });
 
   @override
   Stream<InteractionEvent> reset() {
@@ -104,6 +98,39 @@ class _DesktopFidoStateNotifier extends FidoStateNotifier {
   }
 }
 
+final desktopFidoPinProvider = StateNotifierProvider.autoDispose
+    .family<PinNotifier, bool, DevicePath>((ref, devicePath) {
+  return _DesktopPinNotifier(ref.watch(_sessionProvider(devicePath)),
+      ref.watch(_pinProvider(devicePath).notifier));
+});
+
+class _DesktopPinNotifier extends PinNotifier {
+  final RpcNodeSession _session;
+  final StateController<String?> _pinController;
+
+  _DesktopPinNotifier(this._session, this._pinController)
+      : super(_pinController.state != null);
+
+  @override
+  Future<PinResult> unlock(String pin) async {
+    try {
+      await _session.command(
+        'verify_pin',
+        params: {'pin': pin},
+      );
+      _pinController.state = pin;
+
+      return PinResult.success();
+    } on RpcError catch (e) {
+      if (e.status == 'pin-validation') {
+        _pinController.state = null;
+        return PinResult.failed(e.body['retries'], e.body['auth_blocked']);
+      }
+      rethrow;
+    }
+  }
+}
+
 final desktopFingerprintProvider = StateNotifierProvider.autoDispose.family<
     FidoFingerprintsNotifier,
     AsyncValue<List<Fingerprint>>,
@@ -116,7 +143,7 @@ final desktopFingerprintProvider = StateNotifierProvider.autoDispose.family<
   session.setErrorHandler('auth-required', (_) async {
     final pin = ref.read(_pinProvider(devicePath));
     if (pin != null) {
-      await notifier.unlock(pin, remember: false);
+      await notifier._unlock(pin);
     }
   });
   ref.onDispose(() {
@@ -127,40 +154,33 @@ final desktopFingerprintProvider = StateNotifierProvider.autoDispose.family<
 
 class _DesktopFidoFingerprintsNotifier extends FidoFingerprintsNotifier {
   final RpcNodeSession _session;
-  final StateController<String?> _pin;
-  bool locked = true;
+  final StateController<String?> _pinNotifier;
 
-  _DesktopFidoFingerprintsNotifier(this._session, this._pin) {
-    final pin = _pin.state;
+  _DesktopFidoFingerprintsNotifier(this._session, this._pinNotifier) {
+    final pin = _pinNotifier.state;
     if (pin != null) {
-      unlock(pin, remember: false);
+      _unlock(pin);
     } else {
       state = const AsyncValue.error('locked');
     }
   }
 
-  @override
-  Future<PinResult> unlock(String pin, {bool remember = true}) async {
+  Future<void> _unlock(String pin) async {
     try {
       await _session.command(
         'unlock',
         target: ['fingerprints'],
         params: {'pin': pin},
       );
-      locked = false;
-      if (remember) {
-        _pin.state = pin;
-      }
       await _refresh();
-      return PinResult.success();
     } on RpcError catch (e) {
       if (e.status == 'pin-validation') {
-        _pin.state = null;
-        return PinResult.failed(e.body['retries'], e.body['auth_blocked']);
-      }
+        _pinNotifier.state = null;
+      } else {
         rethrow;
       }
     }
+  }
 
   Future<void> _refresh() async {
     final result = await _session.command('fingerprints');
@@ -242,7 +262,7 @@ final desktopCredentialProvider = StateNotifierProvider.autoDispose.family<
   session.setErrorHandler('auth-required', (_) async {
     final pin = ref.read(_pinProvider(devicePath));
     if (pin != null) {
-      await notifier.unlock(pin, remember: false);
+      await notifier._unlock(pin);
     }
   });
   ref.onDispose(() {
@@ -253,40 +273,33 @@ final desktopCredentialProvider = StateNotifierProvider.autoDispose.family<
 
 class _DesktopFidoCredentialsNotifier extends FidoCredentialsNotifier {
   final RpcNodeSession _session;
-  final StateController<String?> _pin;
-  bool locked = true;
+  final StateController<String?> _pinNotifier;
 
-  _DesktopFidoCredentialsNotifier(this._session, this._pin) {
-    final pin = _pin.state;
+  _DesktopFidoCredentialsNotifier(this._session, this._pinNotifier) {
+    final pin = _pinNotifier.state;
     if (pin != null) {
-      unlock(pin, remember: false);
+      _unlock(pin);
     } else {
       state = const AsyncValue.error('locked');
     }
   }
 
-  @override
-  Future<PinResult> unlock(String pin, {bool remember = true}) async {
+  Future<void> _unlock(String pin) async {
     try {
       await _session.command(
         'unlock',
         target: ['credentials'],
         params: {'pin': pin},
       );
-      locked = false;
-      if (remember) {
-        _pin.state = pin;
-      }
       await _refresh();
-      return PinResult.success();
     } on RpcError catch (e) {
       if (e.status == 'pin-validation') {
-        _pin.state = null;
-        return PinResult.failed(e.body['retries'], e.body['auth_blocked']);
-      }
+        _pinNotifier.state = null;
+      } else {
         rethrow;
       }
     }
+  }
 
   Future<void> _refresh() async {
     final List<FidoCredential> creds = [];

lib/desktop/init.dart

@@ -100,6 +100,7 @@ Future<List<Override>> initializeAndGetOverrides(
     qrScannerProvider.overrideWithProvider(desktopQrScannerProvider),
     managementStateProvider.overrideWithProvider(desktopManagementState),
     fidoStateProvider.overrideWithProvider(desktopFidoState),
+    fidoPinProvider.overrideWithProvider(desktopFidoPinProvider),
     fingerprintProvider.overrideWithProvider(desktopFingerprintProvider),
     credentialProvider.overrideWithProvider(desktopCredentialProvider),
     currentDeviceProvider.overrideWithProvider(desktopCurrentDeviceProvider)

lib/fido/state.dart

@@ -15,10 +15,19 @@ abstract class FidoStateNotifier extends ApplicationStateNotifier<FidoState> {
   Future<PinResult> setPin(String newPin, {String? oldPin});
 }
 
+final fidoPinProvider =
+    StateNotifierProvider.autoDispose.family<PinNotifier, bool, DevicePath>(
+  (ref, devicePath) => throw UnimplementedError(),
+);
+
+abstract class PinNotifier extends StateNotifier<bool> {
+  PinNotifier(bool unlocked) : super(unlocked);
+  Future<PinResult> unlock(String pin);
+}
+
 abstract class LockedCollectionNotifier<T>
     extends StateNotifier<AsyncValue<List<T>>> {
   LockedCollectionNotifier() : super(const AsyncValue.loading());
-  Future<PinResult> unlock(String pin);
 
   @protected
   void setItems(List<T> items) {

lib/fido/views/add_fingerprint_dialog.dart

@@ -41,12 +41,15 @@ class _AddFingerprintDialogState extends ConsumerState<AddFingerprintDialog>
     super.dispose();
   }
 
-  Animation<Color?> _animateColor(Color color, {Function? atPeak}) {
+  Animation<Color?> _animateColor(Color color,
+      {Function? atPeak, bool reverse = true}) {
     final animation =
         ColorTween(begin: Colors.black, end: color).animate(_animator);
     _animator.forward().then((_) {
+      if (reverse) {
         atPeak?.call();
         _animator.reverse();
+      }
     });
     return animation;
   }
@@ -72,7 +75,7 @@ class _AddFingerprintDialogState extends ConsumerState<AddFingerprintDialog>
               _samples += 1;
               _remaining = remaining;
             });
-          });
+          }, reverse: remaining > 0);
         }, complete: (fingerprint) {
           _remaining = 0;
           _fingerprint = fingerprint;

lib/fido/views/credential_page.dart

@@ -2,11 +2,11 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import '../../app/models.dart';
+import '../../app/views/app_failure_screen.dart';
 import '../models.dart';
 import '../state.dart';
 import 'delete_credential_dialog.dart';
 import 'rename_credential_dialog.dart';
-import 'unlock_view.dart';
 
 class CredentialPage extends ConsumerWidget {
   final DeviceNode node;
@@ -18,13 +18,7 @@ class CredentialPage extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     return ref.watch(credentialProvider(node.path)).when(
           loading: () => const Center(child: CircularProgressIndicator()),
-          error: (error, _) => UnlockView(
-            onUnlock: (pin) async {
-              return ref
-                  .read(credentialProvider(node.path).notifier)
-                  .unlock(pin);
-            },
-          ),
+          error: (error, _) => AppFailureScreen('$error'),
           data: (credentials) => ListView(
             children: [
               ListTile(

lib/fido/views/fingerprint_page.dart

@@ -2,12 +2,12 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import '../../app/models.dart';
+import '../../app/views/app_failure_screen.dart';
 import '../models.dart';
 import '../state.dart';
 import 'add_fingerprint_dialog.dart';
 import 'delete_fingerprint_dialog.dart';
 import 'rename_fingerprint_dialog.dart';
-import 'unlock_view.dart';
 
 class FingerprintPage extends ConsumerWidget {
   final DeviceNode node;
@@ -19,13 +19,7 @@ class FingerprintPage extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     return ref.watch(fingerprintProvider(node.path)).when(
           loading: () => const Center(child: CircularProgressIndicator()),
-          error: (error, _) => UnlockView(
-            onUnlock: (pin) async {
-              return ref
-                  .read(fingerprintProvider(node.path).notifier)
-                  .unlock(pin);
-            },
-          ),
+          error: (error, _) => AppFailureScreen('$error'),
           data: (fingerprints) => ListView(
             children: [
               ListTile(

lib/fido/views/main_page.dart

@@ -1,11 +1,14 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import '../../app/models.dart';
 import '../models.dart';
+import '../state.dart';
 import 'pin_dialog.dart';
+import 'pin_entry_dialog.dart';
 import 'reset_dialog.dart';
 
-class FidoMainPage extends StatelessWidget {
+class FidoMainPage extends ConsumerWidget {
   final DeviceNode node;
   final FidoState state;
   final Function(SubPage page) setSubPage;
@@ -14,8 +17,21 @@ class FidoMainPage extends StatelessWidget {
       {required this.setSubPage, Key? key})
       : super(key: key);
 
+  _openLockedPage(BuildContext context, WidgetRef ref, SubPage subPage) async {
+    final unlocked = ref.read(fidoPinProvider(node.path));
+    if (unlocked) {
+      setSubPage(subPage);
+    } else {
+      final result = await showDialog(
+          context: context, builder: (context) => PinEntryDialog(node.path));
+      if (result == true) {
+        setSubPage(subPage);
+      }
+    }
+  }
+
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
     return ListView(
       children: [
         ListTile(
@@ -41,7 +57,7 @@ class FidoMainPage extends StatelessWidget {
                 ? 'Fingerprints have been registered'
                 : 'No fingerprints registered'),
             onTap: () {
-              setSubPage(SubPage.fingerprints);
+              _openLockedPage(context, ref, SubPage.fingerprints);
             },
           ),
         if (state.credMgmt)
@@ -50,14 +66,13 @@ class FidoMainPage extends StatelessWidget {
               child: Icon(Icons.account_box),
             ),
             title: const Text('Credentials'),
+            enabled: state.hasPin,
             subtitle: Text(state.hasPin
                 ? 'Manage stored credentials on key'
                 : 'Set a PIN to manage credentials'),
-            onTap: state.hasPin
-                ? () {
-                    setSubPage(SubPage.credentials);
-                  }
-                : null,
+            onTap: () {
+              _openLockedPage(context, ref, SubPage.credentials);
+            },
           ),
         ListTile(
           leading: const CircleAvatar(

lib/fido/views/pin_entry_dialog.dart

@@ -0,0 +1,93 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../app/models.dart';
+import '../../app/state.dart';
+import '../state.dart';
+
+class PinEntryDialog extends ConsumerStatefulWidget {
+  final DevicePath _devicePath;
+  const PinEntryDialog(this._devicePath, {Key? key}) : super(key: key);
+
+  @override
+  ConsumerState<PinEntryDialog> createState() => _PinEntryDialogState();
+}
+
+class _PinEntryDialogState extends ConsumerState<PinEntryDialog> {
+  final _pinController = TextEditingController();
+  bool _blocked = false;
+  int? _retries;
+
+  void _submit() async {
+    final result = await ref
+        .read(fidoPinProvider(widget._devicePath).notifier)
+        .unlock(_pinController.text);
+    result.when(success: () {
+      Navigator.pop(context, true);
+    }, failed: (retries, authBlocked) {
+      setState(() {
+        _pinController.clear();
+        _retries = retries;
+        _blocked = authBlocked;
+      });
+    });
+  }
+
+  String? _getErrorText() {
+    if (_retries == 0) {
+      return 'PIN is blocked. Factory reset the FIDO application.';
+    }
+    if (_blocked) {
+      return 'PIN temporarily blocked, remove and reinsert your YubiKey.';
+    }
+    if (_retries != null) {
+      return 'Wrong PIN. $_retries attempts remaining.';
+    }
+    return null;
+  }
+
+  @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();
+    });
+
+    return AlertDialog(
+      scrollable: true,
+      title: const Text('Enter PIN'),
+      content: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          const Text(
+            'Enter the FIDO PIN for your YubiKey.',
+          ),
+          TextField(
+            autofocus: true,
+            obscureText: true,
+            controller: _pinController,
+            decoration: InputDecoration(
+              labelText: 'PIN',
+              errorText: _getErrorText(),
+            ),
+            onChanged: (_) => setState(() {}), // Update state on change
+            onSubmitted: (_) => _submit(),
+          ),
+        ],
+      ),
+      actions: [
+        TextButton(
+          child: const Text('Cancel'),
+          onPressed: () {
+            Navigator.of(context).pop();
+          },
+        ),
+        TextButton(
+          child: const Text('Continue'),
+          onPressed:
+              _pinController.text.isNotEmpty && !_blocked ? _submit : null,
+        ),
+      ],
+    );
+  }
+}

lib/fido/views/unlock_view.dart

@@ -1,44 +0,0 @@
-import 'package:flutter/material.dart';
-
-import '../models.dart';
-
-class UnlockView extends StatelessWidget {
-  final Future<PinResult> Function(String pin) onUnlock;
-
-  const UnlockView({required this.onUnlock, Key? key}) : super(key: key);
-
-  @override
-  Widget build(BuildContext context) {
-    return Column(
-      children: [
-        Padding(
-          padding: const EdgeInsets.all(16.0),
-          child: Column(
-            crossAxisAlignment: CrossAxisAlignment.start,
-            children: [
-              Padding(
-                padding: const EdgeInsets.symmetric(vertical: 24.0),
-                child: Text(
-                  'Enter PIN',
-                  style: Theme.of(context).textTheme.headline5,
-                ),
-              ),
-              const Text(
-                'Enter the FIDO PIN for your YubiKey. If you don\'t know your PIN, you\'ll need to reset the YubiKey.',
-              ),
-              TextField(
-                autofocus: true,
-                obscureText: true,
-                decoration: const InputDecoration(labelText: 'PIN'),
-                onSubmitted: (pin) async {
-                  // TODO: Handle wrong PIN
-                  await onUnlock(pin);
-                },
-              ),
-            ],
-          ),
-        ),
-      ],
-    );
-  }
-}