[PM-1249] Clear/reset password/PIN fields on login/lock screen when app is backgrounded (#2395)

* [PM-1249] Clear/reset password/PIN fields on login/lock screen when app is backgrounded

* fixes

src/App/App.xaml.cs

@@ -308,6 +308,7 @@ namespace Bit.App
         private async Task SleptAsync()
         {
             await _vaultTimeoutService.CheckVaultTimeoutAsync();
+            await ClearSensitiveFieldsAsync();
             _messagingService.Send("stopEventTimer");
         }
 
@@ -315,6 +316,7 @@ namespace Bit.App
         {
             await _stateService.CheckExtensionActiveUserAndSwitchIfNeededAsync();
             await _vaultTimeoutService.CheckVaultTimeoutAsync();
+            await ClearSensitiveFieldsAsync();
             _messagingService.Send("startEventTimer");
             await UpdateThemeAsync();
             await ClearCacheIfNeededAsync();
@@ -335,6 +337,14 @@ namespace Bit.App
             });
         }
 
+        private async Task ClearSensitiveFieldsAsync()
+        {
+            await Device.InvokeOnMainThreadAsync(() =>
+            {
+                _messagingService.Send(Constants.ClearSensitiveFields);
+            });
+        }
+
         private void SetCulture()
         {
             // Calendars are removed by linker. ref https://bugzilla.xamarin.com/show_bug.cgi?id=59077

src/App/Pages/Accounts/LockPage.xaml.cs

@@ -3,6 +3,8 @@ using System.Threading.Tasks;
 using Bit.App.Models;
 using Bit.App.Resources;
 using Bit.App.Utilities;
+using Bit.Core;
+using Bit.Core.Abstractions;
 using Bit.Core.Utilities;
 using Xamarin.Forms;
 
@@ -10,6 +12,7 @@ namespace Bit.App.Pages
 {
     public partial class LockPage : BaseContentPage
     {
+        private readonly IBroadcasterService _broadcasterService;
         private readonly AppOptions _appOptions;
         private readonly bool _autoPromptBiometric;
         private readonly LockPageViewModel _vm;
@@ -22,6 +25,7 @@ namespace Bit.App.Pages
             _appOptions = appOptions;
             _autoPromptBiometric = autoPromptBiometric;
             InitializeComponent();
+            _broadcasterService = ServiceContainer.Resolve<IBroadcasterService>();
             _vm = BindingContext as LockPageViewModel;
             _vm.Page = this;
             _vm.UnlockedAction = () => Device.BeginInvokeOnMainThread(async () => await UnlockedAsync());
@@ -64,6 +68,13 @@ namespace Bit.App.Pages
         protected override async void OnAppearing()
         {
             base.OnAppearing();
+            _broadcasterService.Subscribe(nameof(LockPage), message =>
+            {
+                if (message.Command == Constants.ClearSensitiveFields)
+                {
+                    Device.BeginInvokeOnMainThread(_vm.ResetPinPasswordFields);
+                }
+            });
             if (_appeared)
             {
                 return;
@@ -129,6 +140,7 @@ namespace Bit.App.Pages
             base.OnDisappearing();
 
             _accountAvatar?.OnDisappearing();
+            _broadcasterService.Unsubscribe(nameof(LockPage));
         }
 
         private void Unlock_Clicked(object sender, EventArgs e)

src/App/Pages/Accounts/LockPageViewModel.cs

@@ -9,6 +9,7 @@ using Bit.Core.Abstractions;
 using Bit.Core.Enums;
 using Bit.Core.Models.Domain;
 using Bit.Core.Models.Request;
+using Bit.Core.Services;
 using Bit.Core.Utilities;
 using Xamarin.CommunityToolkit.Helpers;
 using Xamarin.Forms;
@@ -32,6 +33,8 @@ namespace Bit.App.Pages
         private readonly WeakEventManager<int?> _secretEntryFocusWeakEventManager = new WeakEventManager<int?>();
 
         private string _email;
+        private string _masterPassword;
+        private string _pin;
         private bool _showPassword;
         private bool _pinLock;
         private bool _biometricLock;
@@ -70,6 +73,18 @@ namespace Bit.App.Pages
             };
         }
 
+        public string MasterPassword
+        {
+            get => _masterPassword;
+            set => SetProperty(ref _masterPassword, value);
+        }
+
+        public string Pin
+        {
+            get => _pin;
+            set => SetProperty(ref _pin, value);
+        }
+
         public bool ShowPassword
         {
             get => _showPassword;
@@ -134,8 +149,6 @@ namespace Bit.App.Pages
         public Command TogglePasswordCommand { get; }
         public string ShowPasswordIcon => ShowPassword ? BitwardenIcons.EyeSlash : BitwardenIcons.Eye;
         public string PasswordVisibilityAccessibilityText => ShowPassword ? AppResources.PasswordIsVisibleTapToHide : AppResources.PasswordIsNotVisibleTapToShow;
-        public string MasterPassword { get; set; }
-        public string Pin { get; set; }
         public Action UnlockedAction { get; set; }
         public event Action<int?> FocusSecretEntry
         {
@@ -349,6 +362,20 @@ namespace Bit.App.Pages
             }
         }
 
+        public void ResetPinPasswordFields()
+        {
+            try
+            {
+                MasterPassword = string.Empty;
+                Pin = string.Empty;
+                ShowPassword = false;
+            }
+            catch (Exception ex)
+            {
+                LoggerHelper.LogEvenIfCantBeResolved(ex);
+            }
+        }
+
         public void TogglePassword()
         {
             ShowPassword = !ShowPassword;

src/App/Pages/Accounts/LoginPage.xaml.cs

@@ -2,6 +2,7 @@
 using System.Threading.Tasks;
 using Bit.App.Models;
 using Bit.App.Utilities;
+using Bit.Core;
 using Bit.Core.Abstractions;
 using Bit.Core.Services;
 using Bit.Core.Utilities;
@@ -12,6 +13,7 @@ namespace Bit.App.Pages
 {
     public partial class LoginPage : BaseContentPage
     {
+        private readonly IBroadcasterService _broadcasterService;
         private readonly LoginPageViewModel _vm;
         private readonly AppOptions _appOptions;
 
@@ -23,6 +25,7 @@ namespace Bit.App.Pages
         {
             _appOptions = appOptions;
             InitializeComponent();
+            _broadcasterService = ServiceContainer.Resolve<IBroadcasterService>();
             _vm = BindingContext as LoginPageViewModel;
             _vm.Page = this;
             _vm.StartTwoFactorAction = () => Device.BeginInvokeOnMainThread(async () => await StartTwoFactorAsync());
@@ -70,6 +73,13 @@ namespace Bit.App.Pages
         protected override async void OnAppearing()
         {
             base.OnAppearing();
+            _broadcasterService.Subscribe(nameof(LoginPage), message =>
+            {
+                if (message.Command == Constants.ClearSensitiveFields)
+                {
+                    Device.BeginInvokeOnMainThread(_vm.ResetPasswordField);
+                }
+            });
             _mainContent.Content = _mainLayout;
             _accountAvatar?.OnAppearing();
 
@@ -104,6 +114,7 @@ namespace Bit.App.Pages
             base.OnDisappearing();
 
             _accountAvatar?.OnDisappearing();
+            _broadcasterService.Unsubscribe(nameof(LoginPage));
         }
 
         private async void LogIn_Clicked(object sender, EventArgs e)

src/App/Pages/Accounts/LoginPageViewModel.cs

@@ -255,6 +255,19 @@ namespace Bit.App.Pages
             }
         }
 
+        public void ResetPasswordField()
+        {
+            try
+            {
+                MasterPassword = string.Empty;
+                ShowPassword = false;
+            }
+            catch (Exception ex)
+            {
+                LoggerHelper.LogEvenIfCantBeResolved(ex);
+            }
+        }
+
         private async Task MoreAsync()
         {
             var buttons = IsEmailEnabled || CanRemoveAccount

src/Core/Constants.cs

@@ -47,6 +47,7 @@
         /// </summary>
         public const string LastUserShouldConnectToWatchKey = "lastUserShouldConnectToWatch";
         public const string AppLocaleKey = "appLocale";
+        public const string ClearSensitiveFields = "clearSensitiveFields";
         public const int SelectFileRequestCode = 42;
         public const int SelectFilePermissionRequestCode = 43;
         public const int SaveFileRequestCode = 44;