[SG-460] Master Password security checks (mobile) (#2312)

* [SG-886] MasterPassword Strength Indicator (#2238)

* [SG-886] Add password strength indicator control

* [SG-570] Add weak password dialog check

* [SG-886] rename enum password strength

* [SG-886] Change control scale

* [SG-886] Move calculate user inputs to IPasswordGenerationService, refactor.

* [SG-886] Move formatted string to xaml. Move minimum chars to constant

* [SG-886] String to enum converter

* [SG-886] PR fixes. Code refactor control

* [SG-886] Update UI on OS theme change.

* [SG-886] Move colors to view

* [SG-886] Fixed password strength validation

* [SG-564][SG-565] Check Exposed Password (#2239)

* [SG-886] Add password strength indicator control

* [SG-570] Add weak password dialog check

* [SG-886] rename enum password strength

* [SG-564] [SG-565] Add check for exposed password and show dialog

* code format

* [SG-886] Change control scale

* [SG-886] Move calculate user inputs to IPasswordGenerationService, refactor.

* [SG-886] Move formatted string to xaml. Move minimum chars to constant

* [SG-886] String to enum converter

* [SG-886] Remove import

* [SG-886] Update UI on OS theme change.

* [SG-886] Move colors to view

* [SG-886] Fixed password strength validation

src/App/App.csproj

@@ -143,6 +143,7 @@
     <Folder Include="Utilities\AccountManagement\" />
     <Folder Include="Controls\DateTime\" />
     <Folder Include="Controls\IconLabelButton\" />
+    <Folder Include="Controls\PasswordStrengthProgressBar\" />
   </ItemGroup>
 
   <ItemGroup>
@@ -435,5 +436,6 @@
     <None Remove="Utilities\AccountManagement\" />
     <None Remove="Controls\DateTime\" />
     <None Remove="Controls\IconLabelButton\" />
+    <None Remove="Controls\PasswordStrengthProgressBar\" />
   </ItemGroup>
 </Project>

src/App/Controls/PasswordStrengthProgressBar/IPasswordStrengthable.cs

@@ -0,0 +1,11 @@
+using System.Collections.Generic;
+
+namespace Bit.App.Controls
+{
+    public interface IPasswordStrengthable
+    {
+        string Password { get; }
+        List<string> UserInputs { get; }
+    }
+}
+

src/App/Controls/PasswordStrengthProgressBar/PasswordStrengthCategory.cs

@@ -0,0 +1,17 @@
+using Bit.Core.Attributes;
+
+namespace Bit.App.Controls
+{
+    public enum PasswordStrengthLevel
+    {
+        [LocalizableEnum("Weak")]
+        VeryWeak,
+        [LocalizableEnum("Weak")]
+        Weak,
+        [LocalizableEnum("Good")]
+        Good,
+        [LocalizableEnum("Strong")]
+        Strong
+    }
+}
+

src/App/Controls/PasswordStrengthProgressBar/PasswordStrengthProgressBar.xaml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<StackLayout
+    xmlns="http://xamarin.com/schemas/2014/forms"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:controls="clr-namespace:Bit.App.Controls"
+    xmlns:u="clr-namespace:Bit.App.Utilities"
+    x:DataType="controls:PasswordStrengthViewModel"
+    x:Class="Bit.App.Controls.PasswordStrengthProgressBar"
+    StyleClass="box">
+    
+    <StackLayout.Resources>
+        <ResourceDictionary>
+            <u:LocalizableEnumConverter x:Key="localizableEnum" />
+        </ResourceDictionary>
+    </StackLayout.Resources>
+
+    <ProgressBar
+        x:Name="_progressBar"
+        u:ProgressBarExtensions.AnimatedProgress="{Binding PasswordStrength}"
+        ScaleY="2" />
+
+    <Label
+        x:Name="_progressLabel"
+        Text="{Binding PasswordStrengthLevel, Converter={StaticResource localizableEnum}, TargetNullValue=' ' }"
+        StyleClass="box-footer-label" />
+
+</StackLayout>
+

src/App/Controls/PasswordStrengthProgressBar/PasswordStrengthProgressBar.xaml.cs

@@ -0,0 +1,107 @@
+using System;
+using Xamarin.Forms;
+
+namespace Bit.App.Controls
+{
+    public partial class PasswordStrengthProgressBar : StackLayout
+    {
+        public static readonly BindableProperty PasswordStrengthLevelProperty = BindableProperty.Create(
+            nameof(PasswordStrengthLevel),
+            typeof(PasswordStrengthLevel),
+            typeof(PasswordStrengthProgressBar),
+            propertyChanged: OnControlPropertyChanged);
+
+        public static readonly BindableProperty VeryWeakColorProperty = BindableProperty.Create(
+            nameof(VeryWeakColor),
+            typeof(Color),
+            typeof(PasswordStrengthProgressBar),
+            propertyChanged: OnControlPropertyChanged);
+
+        public static readonly BindableProperty WeakColorProperty = BindableProperty.Create(
+            nameof(WeakColor),
+            typeof(Color),
+            typeof(PasswordStrengthProgressBar),
+            propertyChanged: OnControlPropertyChanged);
+
+        public static readonly BindableProperty GoodColorProperty = BindableProperty.Create(
+            nameof(GoodColor),
+            typeof(Color),
+            typeof(PasswordStrengthProgressBar),
+            propertyChanged: OnControlPropertyChanged);
+
+        public static readonly BindableProperty StrongColorProperty = BindableProperty.Create(
+            nameof(StrongColor),
+            typeof(Color),
+            typeof(PasswordStrengthProgressBar),
+            propertyChanged: OnControlPropertyChanged);
+
+        public PasswordStrengthLevel? PasswordStrengthLevel
+        {
+            get { return (PasswordStrengthLevel?)GetValue(PasswordStrengthLevelProperty); }
+            set { SetValue(PasswordStrengthLevelProperty, value); }
+        }
+
+        public Color VeryWeakColor
+        {
+            get { return (Color)GetValue(VeryWeakColorProperty); }
+            set { SetValue(VeryWeakColorProperty, value); }
+        }
+
+        public Color WeakColor
+        {
+            get { return (Color)GetValue(WeakColorProperty); }
+            set { SetValue(WeakColorProperty, value); }
+        }
+
+        public Color GoodColor
+        {
+            get { return (Color)GetValue(GoodColorProperty); }
+            set { SetValue(GoodColorProperty, value); }
+        }
+
+        public Color StrongColor
+        {
+            get { return (Color)GetValue(StrongColorProperty); }
+            set { SetValue(StrongColorProperty, value); }
+        }
+
+        public PasswordStrengthProgressBar()
+        {
+            InitializeComponent();
+            SetBinding(PasswordStrengthProgressBar.PasswordStrengthLevelProperty, new Binding() { Path = nameof(PasswordStrengthViewModel.PasswordStrengthLevel) });
+        }
+
+        private static void OnControlPropertyChanged(BindableObject bindable, object oldValue, object newValue)
+        {
+            (bindable as PasswordStrengthProgressBar)?.UpdateColors();
+        }
+
+        public void UpdateColors()
+        {
+            if (_progressBar == null || _progressLabel == null)
+            {
+                return;
+            }
+            _progressBar.ProgressColor = GetColorForStrength();
+            _progressLabel.TextColor = _progressBar.ProgressColor;
+        }
+
+        private Color GetColorForStrength()
+        {
+            switch (PasswordStrengthLevel)
+            {
+                case Controls.PasswordStrengthLevel.VeryWeak:
+                    return VeryWeakColor;
+                case Controls.PasswordStrengthLevel.Weak:
+                    return WeakColor;
+                case Controls.PasswordStrengthLevel.Good:
+                    return GoodColor;
+                case Controls.PasswordStrengthLevel.Strong:
+                    return StrongColor;
+                default:
+                    return Color.Transparent;
+            }
+        }
+    }
+}
+

src/App/Controls/PasswordStrengthProgressBar/PasswordStrengthViewModel.cs

@@ -0,0 +1,67 @@
+using System.Collections.Generic;
+using Bit.Core.Abstractions;
+using Bit.Core.Utilities;
+using Xamarin.Forms;
+
+namespace Bit.App.Controls
+{
+    public class PasswordStrengthViewModel : ExtendedViewModel
+    {
+        private readonly IPasswordGenerationService _passwordGenerationService;
+        private readonly IPasswordStrengthable _passwordStrengthable;
+        private double _passwordStrength;
+        private Color _passwordColor;
+        private PasswordStrengthLevel? _passwordStrengthLevel;
+
+        public PasswordStrengthViewModel(IPasswordStrengthable passwordStrengthable)
+        {
+            _passwordGenerationService = ServiceContainer.Resolve<IPasswordGenerationService>();
+            _passwordStrengthable = passwordStrengthable;
+        }
+
+        public double PasswordStrength
+        {
+            get => _passwordStrength;
+            set => SetProperty(ref _passwordStrength, value);
+        }
+
+        public PasswordStrengthLevel? PasswordStrengthLevel
+        {
+            get => _passwordStrengthLevel;
+            set => SetProperty(ref _passwordStrengthLevel, value);
+        }
+
+        public List<string> GetPasswordStrengthUserInput(string email) => _passwordGenerationService.GetPasswordStrengthUserInput(email);
+
+        public void CalculatePasswordStrength()
+        {
+            if (string.IsNullOrEmpty(_passwordStrengthable.Password))
+            {
+                PasswordStrength = 0;
+                PasswordStrengthLevel = null;
+                return;
+            }
+
+            var passwordStrength = _passwordGenerationService.PasswordStrength(_passwordStrengthable.Password, _passwordStrengthable.UserInputs);
+            // The passwordStrength.Score is 0..4, convertion was made to be used as a progress directly by the control 0..1 
+            PasswordStrength = (passwordStrength.Score + 1f) / 5f;
+            if (PasswordStrength <= 0.4f)
+            {
+                PasswordStrengthLevel = Controls.PasswordStrengthLevel.VeryWeak;
+            }
+            else if (PasswordStrength <= 0.6f)
+            {
+                PasswordStrengthLevel = Controls.PasswordStrengthLevel.Weak;
+            }
+            else if (PasswordStrength <= 0.8f)
+            {
+                PasswordStrengthLevel = Controls.PasswordStrengthLevel.Good;
+            }
+            else
+            {
+                PasswordStrengthLevel = Controls.PasswordStrengthLevel.Strong;
+            }
+        }
+    }
+}
+

src/App/Pages/Accounts/BaseChangePasswordViewModel.cs

@@ -4,6 +4,8 @@ using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using Bit.App.Abstractions;
 using Bit.App.Resources;
+using Bit.App.Utilities;
+using Bit.Core;
 using Bit.Core.Abstractions;
 using Bit.Core.Models.Domain;
 using Bit.Core.Utilities;
@@ -147,8 +149,8 @@ namespace Bit.App.Pages
             }
             if (IsPolicyInEffect)
             {
-                var userInput = await GetPasswordStrengthUserInput();
-                var passwordStrength = _passwordGenerationService.PasswordStrength(MasterPassword, userInput);
+                var userInputs = _passwordGenerationService.GetPasswordStrengthUserInput(await _stateService.GetEmailAsync());
+                var passwordStrength = _passwordGenerationService.PasswordStrength(MasterPassword, userInputs);
                 if (!await _policyService.EvaluateMasterPassword(passwordStrength.Score, MasterPassword, Policy))
                 {
                     await _platformUtilsService.ShowDialogAsync(AppResources.MasterPasswordPolicyValidationMessage,
@@ -158,7 +160,7 @@ namespace Bit.App.Pages
             }
             else
             {
-                if (MasterPassword.Length < 8)
+                if (MasterPassword.Length < Constants.MasterPasswordMinimumChars)
                 {
                     await _platformUtilsService.ShowDialogAsync(AppResources.MasterPasswordLengthValMessage,
                         AppResources.MasterPasswordPolicyValidationTitle, AppResources.Ok);
@@ -174,19 +176,5 @@ namespace Bit.App.Pages
 
             return true;
         }
-
-        private async Task<List<string>> GetPasswordStrengthUserInput()
-        {
-            var email = await _stateService.GetEmailAsync();
-            List<string> userInput = null;
-            var atPosition = email.IndexOf('@');
-            if (atPosition > -1)
-            {
-                var rx = new Regex("/[^A-Za-z0-9]/", RegexOptions.Compiled);
-                var data = rx.Split(email.Substring(0, atPosition).Trim().ToLower());
-                userInput = new List<string>(data);
-            }
-            return userInput;
-        }
     }
 }

src/App/Pages/Accounts/RegisterPage.xaml

@@ -25,7 +25,7 @@
     </ContentPage.ToolbarItems>
 
     <ScrollView>
-        <StackLayout Spacing="20">
+        <StackLayout Spacing="10">
             <StackLayout StyleClass="box">
                 <StackLayout StyleClass="box-row">
                     <Label
@@ -72,8 +72,19 @@
                         AutomationProperties.HelpText="{Binding PasswordVisibilityAccessibilityText}"/>
                 </Grid>
                 <Label
-                    Text="{u:I18n MasterPasswordDescription}"
-                    StyleClass="box-footer-label" />
+                    StyleClass="box-sub-label"
+                    Margin="0,0,0,10">
+                        <Label.FormattedText>
+                            <FormattedString>
+                                <Span Text="{u:I18n Important}" TextColor="{DynamicResource InfoColor}"/>
+                                <Span Text=": " TextColor="{DynamicResource InfoColor}"/>
+                                <Span Text="{Binding MasterPasswordMininumCharactersDescription}" TextColor="{DynamicResource MutedColor}"/>
+                            </FormattedString>
+                        </Label.FormattedText>
+                </Label>
+                <controls:PasswordStrengthProgressBar
+                    BindingContext="{Binding PasswordStrengthViewModel}"
+                    Margin="0,0"/>
             </StackLayout>
             <StackLayout StyleClass="box">
                 <Grid StyleClass="box-row">
@@ -126,6 +137,17 @@
                     StyleClass="box-footer-label" />
             </StackLayout>
             <StackLayout StyleClass="box">
+                <StackLayout StyleClass="box-row, box-row-switch">
+                    <Switch
+                        IsToggled="{Binding CheckExposedMasterPassword}"
+                        StyleClass="box-value"
+                        HorizontalOptions="Start"
+                        Margin="0, 0, 10, 0"/>
+                    <Label
+                        Text="{u:I18n CheckKnownDataBreachesForThisPassword}"
+                        StyleClass="box-footer-label"
+                        VerticalOptions="Center"/>
+                </StackLayout>
                 <StackLayout StyleClass="box-row, box-row-switch"
                             IsVisible="{Binding ShowTerms}">
                     <Switch

src/App/Pages/Accounts/RegisterPageViewModel.cs

@@ -1,28 +1,36 @@
 using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 using System.Windows.Input;
 using Bit.App.Abstractions;
+using Bit.App.Controls;
 using Bit.App.Resources;
+using Bit.App.Utilities;
 using Bit.Core;
 using Bit.Core.Abstractions;
 using Bit.Core.Enums;
 using Bit.Core.Exceptions;
 using Bit.Core.Models.Request;
+using Bit.Core.Services;
 using Bit.Core.Utilities;
 using Xamarin.Forms;
 
 namespace Bit.App.Pages
 {
-    public class RegisterPageViewModel : CaptchaProtectedViewModel
+    public class RegisterPageViewModel : CaptchaProtectedViewModel, IPasswordStrengthable
     {
         private readonly IDeviceActionService _deviceActionService;
         private readonly II18nService _i18nService;
         private readonly IEnvironmentService _environmentService;
+        private readonly IAuditService _auditService;
         private readonly IApiService _apiService;
         private readonly ICryptoService _cryptoService;
         private readonly IPlatformUtilsService _platformUtilsService;
+        private string _email;
+        private string _masterPassword;
         private bool _showPassword;
         private bool _acceptPolicies;
+        private bool _checkExposedMasterPassword;
 
         public RegisterPageViewModel()
         {
@@ -32,12 +40,14 @@ namespace Bit.App.Pages
             _platformUtilsService = ServiceContainer.Resolve<IPlatformUtilsService>("platformUtilsService");
             _i18nService = ServiceContainer.Resolve<II18nService>("i18nService");
             _environmentService = ServiceContainer.Resolve<IEnvironmentService>("environmentService");
+            _auditService = ServiceContainer.Resolve<IAuditService>();
 
             PageTitle = AppResources.CreateAccount;
             TogglePasswordCommand = new Command(TogglePassword);
             ToggleConfirmPasswordCommand = new Command(ToggleConfirmPassword);
             SubmitCommand = new Command(async () => await SubmitAsync());
             ShowTerms = !_platformUtilsService.IsSelfHost();
+            PasswordStrengthViewModel = new PasswordStrengthViewModel(this);
         }
 
         public ICommand PoliciesClickCommand => new Command<string>((url) =>
@@ -61,6 +71,34 @@ namespace Bit.App.Pages
             get => _acceptPolicies;
             set => SetProperty(ref _acceptPolicies, value);
         }
+
+        public bool CheckExposedMasterPassword
+        {
+            get => _checkExposedMasterPassword;
+            set => SetProperty(ref _checkExposedMasterPassword, value);
+        }
+
+        public string MasterPassword
+        {
+            get => _masterPassword;
+            set
+            {
+                SetProperty(ref _masterPassword, value);
+                PasswordStrengthViewModel.CalculatePasswordStrength();
+            }
+        }
+
+        public string Email
+        {
+            get => _email;
+            set => SetProperty(ref _email, value);
+        }
+
+        public string Password => MasterPassword;
+        public List<string> UserInputs => PasswordStrengthViewModel.GetPasswordStrengthUserInput(Email);
+        public string MasterPasswordMininumCharactersDescription => string.Format(AppResources.YourMasterPasswordCannotBeRecoveredIfYouForgetItXCharactersMinimum,
+                                                                            Constants.MasterPasswordMinimumChars);
+        public PasswordStrengthViewModel PasswordStrengthViewModel { get; }
         public bool ShowTerms { get; set; }
         public Command SubmitCommand { get; }
         public Command TogglePasswordCommand { get; }
@@ -68,13 +106,10 @@ namespace Bit.App.Pages
         public string ShowPasswordIcon => ShowPassword ? BitwardenIcons.EyeSlash : BitwardenIcons.Eye;
         public string PasswordVisibilityAccessibilityText => ShowPassword ? AppResources.PasswordIsVisibleTapToHide : AppResources.PasswordIsNotVisibleTapToShow;
         public string Name { get; set; }
-        public string Email { get; set; }
-        public string MasterPassword { get; set; }
         public string ConfirmMasterPassword { get; set; }
         public string Hint { get; set; }
         public Action RegistrationSuccess { get; set; }
         public Action CloseAction { get; set; }
-
         protected override II18nService i18nService => _i18nService;
         protected override IEnvironmentService environmentService => _environmentService;
         protected override IDeviceActionService deviceActionService => _deviceActionService;
@@ -110,7 +145,7 @@ namespace Bit.App.Pages
                     AppResources.Ok);
                 return;
             }
-            if (MasterPassword.Length < 8)
+            if (MasterPassword.Length < Constants.MasterPasswordMinimumChars)
             {
                 await _platformUtilsService.ShowDialogAsync(AppResources.MasterPasswordLengthValMessage,
                     AppResources.AnErrorHasOccurred, AppResources.Ok);
@@ -128,8 +163,10 @@ namespace Bit.App.Pages
                     AppResources.AnErrorHasOccurred, AppResources.Ok);
                 return;
             }
-
-            // TODO: Password strength check?
+            if (await IsPasswordWeakOrExposed())
+            {
+                return;
+            }
 
             if (showLoading)
             {
@@ -160,6 +197,7 @@ namespace Bit.App.Pages
                 },
                 CaptchaResponse = _captchaToken,
             };
+
             // TODO: org invite?
 
             try
@@ -208,5 +246,43 @@ namespace Bit.App.Pages
             entry.Focus();
             entry.CursorPosition = String.IsNullOrEmpty(ConfirmMasterPassword) ? 0 : ConfirmMasterPassword.Length;
         }
+
+        private async Task<bool> IsPasswordWeakOrExposed()
+        {
+            try
+            {
+                var title = string.Empty;
+                var message = string.Empty;
+                var exposedPassword = CheckExposedMasterPassword ? await _auditService.PasswordLeakedAsync(MasterPassword) > 0 : false;
+                var weakPassword = PasswordStrengthViewModel.PasswordStrengthLevel <= PasswordStrengthLevel.Weak;
+
+                if (exposedPassword && weakPassword)
+                {
+                    title = AppResources.WeakAndExposedMasterPassword;
+                    message = AppResources.WeakPasswordIdentifiedAndFoundInADataBreachAlertDescription;
+                }
+                else if (exposedPassword)
+                {
+                    title = AppResources.ExposedMasterPassword;
+                    message = AppResources.PasswordFoundInADataBreachAlertDescription;
+                }
+                else if (weakPassword)
+                {
+                    title = AppResources.WeakMasterPassword;
+                    message = AppResources.WeakPasswordIdentifiedUseAStrongPasswordToProtectYourAccount;
+                }
+
+                if (exposedPassword || weakPassword)
+                {
+                    return !await _platformUtilsService.ShowDialogAsync(message, title, AppResources.Yes, AppResources.No);
+                }
+            }
+            catch (Exception ex)
+            {
+                HandleException(ex);
+            }
+
+            return false;
+        }
     }
 }

src/App/Pages/Accounts/SetPasswordPageViewModel.cs

@@ -5,6 +5,7 @@ using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using Bit.App.Abstractions;
 using Bit.App.Resources;
+using Bit.App.Utilities;
 using Bit.Core;
 using Bit.Core.Abstractions;
 using Bit.Core.Enums;
@@ -137,8 +138,8 @@ namespace Bit.App.Pages
             }
             if (IsPolicyInEffect)
             {
-                var userInput = await GetPasswordStrengthUserInput();
-                var passwordStrength = _passwordGenerationService.PasswordStrength(MasterPassword, userInput);
+                var userInputs = _passwordGenerationService.GetPasswordStrengthUserInput(await _stateService.GetEmailAsync());
+                var passwordStrength = _passwordGenerationService.PasswordStrength(MasterPassword, userInputs);
                 if (!await _policyService.EvaluateMasterPassword(passwordStrength.Score, MasterPassword, Policy))
                 {
                     await Page.DisplayAlert(AppResources.MasterPasswordPolicyValidationTitle,
@@ -148,7 +149,7 @@ namespace Bit.App.Pages
             }
             else
             {
-                if (MasterPassword.Length < 8)
+                if (MasterPassword.Length < Constants.MasterPasswordMinimumChars)
                 {
                     await Page.DisplayAlert(AppResources.MasterPasswordPolicyValidationTitle,
                         AppResources.MasterPasswordLengthValMessage, AppResources.Ok);

src/App/Pages/BaseViewModel.cs

@@ -3,6 +3,7 @@ using Bit.App.Abstractions;
 using Bit.App.Controls;
 using Bit.App.Resources;
 using Bit.Core.Abstractions;
+using Bit.Core.Exceptions;
 using Bit.Core.Services;
 using Bit.Core.Utilities;
 using Xamarin.Forms;
@@ -33,6 +34,11 @@ namespace Bit.App.Pages
 
         protected void HandleException(Exception ex, string message = null)
         {
+            if (ex is ApiException apiException && apiException.Error != null)
+            {
+                message = apiException.Error.GetSingleMessage();
+            }
+
             Xamarin.Essentials.MainThread.InvokeOnMainThreadAsync(async () =>
             {
                 await _deviceActionService.Value.HideLoadingAsync();

src/App/Resources/AppResources.Designer.cs

@@ -1372,6 +1372,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Check known data breaches for this password.
+        /// </summary>
+        public static string CheckKnownDataBreachesForThisPassword {
+            get {
+                return ResourceManager.GetString("CheckKnownDataBreachesForThisPassword", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Check if password has been exposed..
         /// </summary>
@@ -2416,6 +2425,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Exposed Master Password.
+        /// </summary>
+        public static string ExposedMasterPassword {
+            get {
+                return ResourceManager.GetString("ExposedMasterPassword", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Extension activated!.
         /// </summary>
@@ -2938,6 +2956,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Good.
+        /// </summary>
+        public static string Good {
+            get {
+                return ResourceManager.GetString("Good", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Go to my vault.
         /// </summary>
@@ -3073,6 +3100,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Important.
+        /// </summary>
+        public static string Important {
+            get {
+                return ResourceManager.GetString("Important", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Import items.
         /// </summary>
@@ -4570,6 +4606,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Password found in a data breach. Use a unique password to protect your account. Are you sure you want to use an exposed password?.
+        /// </summary>
+        public static string PasswordFoundInADataBreachAlertDescription {
+            get {
+                return ResourceManager.GetString("PasswordFoundInADataBreachAlertDescription", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Password generated.
         /// </summary>
@@ -5669,6 +5714,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Strong.
+        /// </summary>
+        public static string Strong {
+            get {
+                return ResourceManager.GetString("Strong", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Submit.
         /// </summary>
@@ -6650,6 +6704,51 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Weak.
+        /// </summary>
+        public static string Weak {
+            get {
+                return ResourceManager.GetString("Weak", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Weak and Exposed Master Password.
+        /// </summary>
+        public static string WeakAndExposedMasterPassword {
+            get {
+                return ResourceManager.GetString("WeakAndExposedMasterPassword", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Weak Master Password.
+        /// </summary>
+        public static string WeakMasterPassword {
+            get {
+                return ResourceManager.GetString("WeakMasterPassword", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Weak password identified and found in a data breach. Use a strong and unique password to protect your account. Are you sure you want to use this password?.
+        /// </summary>
+        public static string WeakPasswordIdentifiedAndFoundInADataBreachAlertDescription {
+            get {
+                return ResourceManager.GetString("WeakPasswordIdentifiedAndFoundInADataBreachAlertDescription", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Weak password identified. Use a strong password to protect your account. Are you sure you want to use a weak password?.
+        /// </summary>
+        public static string WeakPasswordIdentifiedUseAStrongPasswordToProtectYourAccount {
+            get {
+                return ResourceManager.GetString("WeakPasswordIdentifiedUseAStrongPasswordToProtectYourAccount", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Website.
         /// </summary>
@@ -6767,6 +6866,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Your master password cannot be recovered if you forget it! {0} characters minimum..
+        /// </summary>
+        public static string YourMasterPasswordCannotBeRecoveredIfYouForgetItXCharactersMinimum {
+            get {
+                return ResourceManager.GetString("YourMasterPasswordCannotBeRecoveredIfYouForgetItXCharactersMinimum", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to To continue, hold your YubiKey NEO against the back of the device or insert your YubiKey into your device&apos;s USB port, then touch its button..
         /// </summary>

src/App/Resources/AppResources.resx

@@ -2515,4 +2515,40 @@ Do you want to switch to this account?</value>
   <data name="EnableCamerPermissionToUseTheScanner" xml:space="preserve">
     <value>Enable camera permission to use the scanner</value>
   </data>
+  <data name="Important" xml:space="preserve">
+    <value>Important</value>
+  </data>
+  <data name="YourMasterPasswordCannotBeRecoveredIfYouForgetItXCharactersMinimum" xml:space="preserve">
+    <value>Your master password cannot be recovered if you forget it! {0} characters minimum.</value>
+  </data>
+  <data name="WeakMasterPassword" xml:space="preserve">
+    <value>Weak Master Password</value>
+  </data>
+  <data name="WeakPasswordIdentifiedUseAStrongPasswordToProtectYourAccount" xml:space="preserve">
+    <value>Weak password identified. Use a strong password to protect your account. Are you sure you want to use a weak password?</value>
+  </data>
+  <data name="Weak" xml:space="preserve">
+    <value>Weak</value>
+  </data>
+  <data name="Good" xml:space="preserve">
+    <value>Good</value>
+  </data>
+  <data name="Strong" xml:space="preserve">
+    <value>Strong</value>
+  </data>
+  <data name="CheckKnownDataBreachesForThisPassword" xml:space="preserve">
+    <value>Check known data breaches for this password</value>
+  </data>
+  <data name="ExposedMasterPassword" xml:space="preserve">
+    <value>Exposed Master Password</value>
+  </data>
+  <data name="PasswordFoundInADataBreachAlertDescription" xml:space="preserve">
+    <value>Password found in a data breach. Use a unique password to protect your account. Are you sure you want to use an exposed password?</value>
+  </data>
+  <data name="WeakAndExposedMasterPassword" xml:space="preserve">
+    <value>Weak and Exposed Master Password</value>
+  </data>
+  <data name="WeakPasswordIdentifiedAndFoundInADataBreachAlertDescription" xml:space="preserve">
+    <value>Weak password identified and found in a data breach. Use a strong and unique password to protect your account. Are you sure you want to use this password?</value>
+  </data>
 </root>

src/App/Styles/Base.xaml

@@ -562,4 +562,15 @@
             </VisualStateGroupList>
         </Setter>
     </Style>
+    
+    <Style TargetType="controls:PasswordStrengthProgressBar">
+        <Setter Property="VeryWeakColor"
+                Value="{DynamicResource DangerColor}" />
+        <Setter Property="WeakColor"
+                Value="{DynamicResource WarningColor}" />
+        <Setter Property="GoodColor"
+                Value="{DynamicResource PrimaryColor}" />
+        <Setter Property="StrongColor"
+                Value="{DynamicResource SuccessColor}" />
+    </Style>
 </ResourceDictionary>

src/App/Utilities/ProgressBarExtensions.cs

@@ -0,0 +1,25 @@
+using Xamarin.Forms;
+
+namespace Bit.App.Utilities
+{
+    public static class ProgressBarExtensions
+    {
+        public static BindableProperty AnimatedProgressProperty =
+           BindableProperty.CreateAttached("AnimatedProgress",
+           typeof(double),
+           typeof(ProgressBar),
+           0.0d,
+           BindingMode.OneWay,
+           propertyChanged: (b, o, n) => ProgressBarProgressChanged((ProgressBar)b, (double)n));
+
+        public static double GetAnimatedProgress(BindableObject target) => (double)target.GetValue(AnimatedProgressProperty);
+        public static void SetAnimatedProgress(BindableObject target, double value) => target.SetValue(AnimatedProgressProperty, value);
+
+        private static void ProgressBarProgressChanged(ProgressBar progressBar, double progress)
+        {
+            ViewExtensions.CancelAnimations(progressBar);
+            progressBar.ProgressTo(progress, 500, Easing.SinIn);
+        }
+    }
+}
+

src/Core/Abstractions/IPasswordGenerationService.cs

@@ -2,6 +2,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Bit.Core.Models.Domain;
+using Zxcvbn;
 
 namespace Bit.Core.Abstractions
 {
@@ -16,8 +17,9 @@ namespace Bit.Core.Abstractions
         Task<(PasswordGenerationOptions, PasswordGeneratorPolicyOptions)> GetOptionsAsync();
         Task<(PasswordGenerationOptions, PasswordGeneratorPolicyOptions)>
             EnforcePasswordGeneratorPoliciesOnOptionsAsync(PasswordGenerationOptions options);
-        Zxcvbn.Result PasswordStrength(string password, List<string> userInputs = null);
+        Result PasswordStrength(string password, List<string> userInputs = null);
         Task SaveOptionsAsync(PasswordGenerationOptions options);
         void NormalizeOptions(PasswordGenerationOptions options, PasswordGeneratorPolicyOptions enforcedPolicyOptions);
+        List<string> GetPasswordStrengthUserInput(string email);
     }
 }

src/Core/Constants.cs

@@ -46,6 +46,7 @@
         public const int SaveFileRequestCode = 44;
         public const int TotpDefaultTimer = 30;
         public const int PasswordlessNotificationTimeoutInMinutes = 15;
+        public const int MasterPasswordMinimumChars = 8;
 
         public static readonly string[] AndroidAllClearCipherCacheKeys =
         {

src/Core/Services/PasswordGenerationService.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
 using Bit.Core.Abstractions;
@@ -395,6 +396,19 @@ namespace Bit.Core.Services
             return enforcedOptions;
         }
 
+        public List<string> GetPasswordStrengthUserInput(string email)
+        {
+            var atPosition = email?.IndexOf('@');
+            if (atPosition is null || atPosition < 0)
+            {
+                return null;
+            }
+            var rx = new Regex("/[^A-Za-z0-9]/", RegexOptions.Compiled);
+            var data = rx.Split(email.Substring(0, atPosition.Value).Trim().ToLower());
+
+            return new List<string>(data);
+        }
+
         private int? GetPolicyInt(Policy policy, string key)
         {
             if (policy.Data.ContainsKey(key))