use native biomatrics on Android

src/Android/Services/DeviceActionService.cs

@@ -8,9 +8,11 @@ using Android.App;
 using Android.App.Assist;
 using Android.Content;
 using Android.Content.PM;
+using Android.Hardware.Biometrics;
 using Android.Nfc;
 using Android.OS;
 using Android.Provider;
+using Android.Runtime;
 using Android.Support.V4.App;
 using Android.Support.V4.Content;
 using Android.Text;
@@ -28,6 +30,7 @@ using Bit.Core.Models.View;
 using Bit.Core.Utilities;
 using Bit.Droid.Autofill;
 using Plugin.CurrentActivity;
+using Plugin.Fingerprint;
 
 namespace Bit.Droid.Services
 {
@@ -335,11 +338,72 @@ namespace Bit.Droid.Services
                 Application.Context.PackageName, 0).VersionCode.ToString();
         }
 
-        public bool SupportsFaceId()
+        public bool SupportsFaceBiometric()
         {
             return false;
         }
 
+        public Task<bool> SupportsFaceBiometricAsync()
+        {
+            return Task.FromResult(SupportsFaceBiometric());
+        }
+
+        public async Task<bool> BiometricAvailableAsync()
+        {
+            if(UseNativeBiometric())
+            {
+                var activity = (MainActivity)CrossCurrentActivity.Current.Activity;
+                var manager = activity.GetSystemService(Context.BiometricService) as BiometricManager;
+                return manager.CanAuthenticate() == BiometricCode.Success;
+            }
+            else
+            {
+                try
+                {
+                    return await CrossFingerprint.Current.IsAvailableAsync();
+                }
+                catch
+                {
+                    return false;
+                }
+            }
+        }
+
+        public bool UseNativeBiometric()
+        {
+            return (int)Build.VERSION.SdkInt >= 28;
+        }
+
+        public Task<bool> AuthenticateBiometricAsync(string text = null)
+        {
+            if(string.IsNullOrWhiteSpace(text))
+            {
+                text = AppResources.BiometricDirection;
+            }
+
+            var activity = (MainActivity)CrossCurrentActivity.Current.Activity;
+            using(var builder = new BiometricPrompt.Builder(activity))
+            {
+                builder.SetTitle(text);
+                builder.SetConfirmationRequired(false);
+                builder.SetNegativeButton(AppResources.Cancel, activity.MainExecutor,
+                    new DialogInterfaceOnClickListener
+                    {
+                        Clicked = () => { }
+                    });
+                var prompt = builder.Build();
+                var result = new TaskCompletionSource<bool>();
+                prompt.Authenticate(new CancellationSignal(), activity.MainExecutor,
+                    new BiometricAuthenticationCallback
+                    {
+                        Success = authResult => result.TrySetResult(true),
+                        Failed = () => result.TrySetResult(false),
+                        Help = (helpCode, helpString) => { }
+                    });
+                return result.Task;
+            }
+        }
+
         public bool SupportsNfc()
         {
             var activity = (MainActivity)CrossCurrentActivity.Current.Activity;
@@ -715,5 +779,41 @@ namespace Bit.Droid.Services
                 Context.ClipboardService) as Android.Content.ClipboardManager;
             clipboardManager.Text = text;
         }
+
+        private class BiometricAuthenticationCallback : BiometricPrompt.AuthenticationCallback
+        {
+            public Action<BiometricPrompt.AuthenticationResult> Success { get; set; }
+            public Action Failed { get; set; }
+            public Action<BiometricAcquiredStatus, Java.Lang.ICharSequence> Help { get; set; }
+
+            public override void OnAuthenticationSucceeded(BiometricPrompt.AuthenticationResult authResult)
+            {
+                base.OnAuthenticationSucceeded(authResult);
+                Success?.Invoke(authResult);
+            }
+
+            public override void OnAuthenticationFailed()
+            {
+                base.OnAuthenticationFailed();
+                Failed?.Invoke();
+            }
+
+            public override void OnAuthenticationHelp([GeneratedEnum] BiometricAcquiredStatus helpCode,
+                Java.Lang.ICharSequence helpString)
+            {
+                base.OnAuthenticationHelp(helpCode, helpString);
+                Help?.Invoke(helpCode, helpString);
+            }
+        }
+
+        private class DialogInterfaceOnClickListener : Java.Lang.Object, IDialogInterfaceOnClickListener
+        {
+            public Action Clicked { get; set; }
+
+            public void OnClick(IDialogInterface dialog, int which)
+            {
+                Clicked?.Invoke();
+            }
+        }
     }
 }

src/App/Abstractions/IDeviceActionService.cs

@@ -20,7 +20,11 @@ namespace Bit.App.Abstractions
             string okButtonText = null, string cancelButtonText = null, bool numericKeyboard = false,
             bool autofocus = true);
         void RateApp();
-        bool SupportsFaceId();
+        bool SupportsFaceBiometric();
+        Task<bool> SupportsFaceBiometricAsync();
+        Task<bool> BiometricAvailableAsync();
+        bool UseNativeBiometric();
+        Task<bool> AuthenticateBiometricAsync(string text = null);
         bool SupportsNfc();
         bool SupportsCamera();
         bool SupportsAutofillService();

src/App/Pages/Accounts/LockPageViewModel.cs

@@ -126,7 +126,8 @@ namespace Bit.App.Pages
 
             if(FingerprintLock)
             {
-                FingerprintButtonText = _deviceActionService.SupportsFaceId() ? AppResources.UseFaceIDToUnlock :
+                var supportsFace = await _deviceActionService.SupportsFaceBiometricAsync();
+                FingerprintButtonText = supportsFace ? AppResources.UseFaceIDToUnlock :
                     AppResources.UseFingerprintToUnlock;
                 if(autoPromptFingerprint)
                 {
@@ -266,7 +267,7 @@ namespace Bit.App.Pages
             {
                 return;
             }
-            var success = await _platformUtilsService.AuthenticateFingerprintAsync(null,
+            var success = await _platformUtilsService.AuthenticateBiometricAsync(null,
             PinLock ? AppResources.PIN : AppResources.MasterPassword, () =>
             {
                 var page = Page as LockPage;

src/App/Pages/Settings/SettingsPage/SettingsPage.xaml.cs

@@ -142,8 +142,8 @@ namespace Bit.App.Pages
                 var fingerprintName = AppResources.Fingerprint;
                 if(Device.RuntimePlatform == Device.iOS)
                 {
-                    fingerprintName = _deviceActionService.SupportsFaceId() ?
+                    var supportsFace = await _deviceActionService.SupportsFaceBiometricAsync();
-                        AppResources.FaceID : AppResources.TouchID;
+                    fingerprintName = supportsFace ? AppResources.FaceID : AppResources.TouchID;
                 }
                 if(item.Name == string.Format(AppResources.UnlockWith, fingerprintName))
                 {

src/App/Pages/Settings/SettingsPage/SettingsPageViewModel.cs

@@ -62,7 +62,7 @@ namespace Bit.App.Pages
 
         public async Task InitAsync()
         {
-            _supportsFingerprint = await _platformUtilsService.SupportsFingerprintAsync();
+            _supportsFingerprint = await _platformUtilsService.SupportsBiometricAsync();
             var lastSync = await _syncService.GetLastSyncAsync();
             if(lastSync != null)
             {
@@ -255,9 +255,9 @@ namespace Bit.App.Pages
             {
                 _fingerprint = false;
             }
-            else if(await _platformUtilsService.SupportsFingerprintAsync())
+            else if(await _platformUtilsService.SupportsBiometricAsync())
             {
-                _fingerprint = await _platformUtilsService.AuthenticateFingerprintAsync(null,
+                _fingerprint = await _platformUtilsService.AuthenticateBiometricAsync(null,
                     _deviceActionService.DeviceType == Core.Enums.DeviceType.Android ? "." : null);
             }
             if(_fingerprint == current)
@@ -328,8 +328,8 @@ namespace Bit.App.Pages
                 var fingerprintName = AppResources.Fingerprint;
                 if(Device.RuntimePlatform == Device.iOS)
                 {
-                    fingerprintName = _deviceActionService.SupportsFaceId() ?
+                    fingerprintName = _deviceActionService.SupportsFaceBiometric() ? AppResources.FaceID :
-                        AppResources.FaceID : AppResources.TouchID;
+                        AppResources.TouchID;
                 }
                 var item = new SettingsPageListItem
                 {

src/App/Resources/AppResources.Designer.cs

@@ -537,6 +537,15 @@ namespace Bit.App.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Use biometrics to verify..
+        /// </summary>
+        public static string BiometricDirection {
+            get {
+                return ResourceManager.GetString("BiometricDirection", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Bitwarden.
         /// </summary>

src/App/Resources/AppResources.resx

@@ -1578,4 +1578,7 @@
   <data name="LoginExpired" xml:space="preserve">
     <value>Your login session has expired.</value>
   </data>
+  <data name="BiometricDirection" xml:space="preserve">
+    <value>Use biometrics to verify.</value>
+  </data>
 </root>

src/App/Services/MobilePlatformUtilsService.cs

@@ -197,45 +197,45 @@ namespace Bit.App.Services
             return await Clipboard.GetTextAsync();
         }
 
-        public async Task<bool> SupportsFingerprintAsync()
+        public async Task<bool> SupportsBiometricAsync()
         {
-            try
+            return await _deviceActionService.BiometricAvailableAsync();
+        }
+
+        public async Task<bool> AuthenticateBiometricAsync(string text = null, string fallbackText = null,
+            Action fallback = null)
+        {
+            if(_deviceActionService.UseNativeBiometric())
             {
-                return await CrossFingerprint.Current.IsAvailableAsync();
+                return await _deviceActionService.AuthenticateBiometricAsync(text);
             }
-            catch
+            else
             {
+                try
+                {
+                    if(text == null)
+                    {
+                        var supportsFace = await _deviceActionService.SupportsFaceBiometricAsync();
+                        text = supportsFace ? AppResources.FaceIDDirection : AppResources.FingerprintDirection;
+                    }
+                    var fingerprintRequest = new AuthenticationRequestConfiguration(text)
+                    {
+                        CancelTitle = AppResources.Cancel,
+                        FallbackTitle = fallbackText
+                    };
+                    var result = await CrossFingerprint.Current.AuthenticateAsync(fingerprintRequest);
+                    if(result.Authenticated)
+                    {
+                        return true;
+                    }
+                    else if(result.Status == FingerprintAuthenticationResultStatus.FallbackRequested)
+                    {
+                        fallback?.Invoke();
+                    }
+                }
+                catch { }
                 return false;
             }
         }
-
-        public async Task<bool> AuthenticateFingerprintAsync(string text = null, string fallbackText = null,
-            Action fallback = null)
-        {
-            try
-            {
-                if(text == null)
-                {
-                    text = _deviceActionService.SupportsFaceId() ? AppResources.FaceIDDirection :
-                        AppResources.FingerprintDirection;
-                }
-                var fingerprintRequest = new AuthenticationRequestConfiguration(text)
-                {
-                    CancelTitle = AppResources.Cancel,
-                    FallbackTitle = fallbackText
-                };
-                var result = await CrossFingerprint.Current.AuthenticateAsync(fingerprintRequest);
-                if(result.Authenticated)
-                {
-                    return true;
-                }
-                else if(result.Status == FingerprintAuthenticationResultStatus.FallbackRequested)
-                {
-                    fallback?.Invoke();
-                }
-            }
-            catch { }
-            return false;
-        }
     }
 }

src/Core/Abstractions/IPlatformUtilsService.cs

@@ -26,7 +26,7 @@ namespace Bit.Core.Abstractions
         void ShowToast(string type, string title, string[] text, Dictionary<string, object> options = null);
         bool SupportsU2f();
         bool SupportsDuo();
-        Task<bool> SupportsFingerprintAsync();
+        Task<bool> SupportsBiometricAsync();
-        Task<bool> AuthenticateFingerprintAsync(string text = null, string fallbackText = null, Action fallback = null);
+        Task<bool> AuthenticateBiometricAsync(string text = null, string fallbackText = null, Action fallback = null);
     }
 }

src/iOS.Core/Controllers/LockPasswordViewController.cs

@@ -216,7 +216,7 @@ namespace Bit.iOS.Core.Controllers
             {
                 return;
             }
-            var success = await _platformUtilsService.AuthenticateFingerprintAsync(null,
+            var success = await _platformUtilsService.AuthenticateBiometricAsync(null,
                 _pinLock ? AppResources.PIN : AppResources.MasterPassword,
                 () => MasterPasswordCell.TextField.BecomeFirstResponder());
             _lockService.FingerprintLocked = !success;
@@ -261,7 +261,7 @@ namespace Bit.iOS.Core.Controllers
                 {
                     if(indexPath.Row == 0)
                     {
-                        var fingerprintButtonText = _controller._deviceActionService.SupportsFaceId() ?
+                        var fingerprintButtonText = _controller._deviceActionService.SupportsFaceBiometric() ?
                             AppResources.UseFaceIDToUnlock : AppResources.UseFingerprintToUnlock;
                         var cell = new ExtendedUITableViewCell();
                         cell.TextLabel.TextColor = ThemeHelpers.PrimaryColor;

src/iOS.Core/Services/DeviceActionService.cs

@@ -15,6 +15,7 @@ using Foundation;
 using LocalAuthentication;
 using MobileCoreServices;
 using Photos;
+using Plugin.Fingerprint;
 using UIKit;
 using Xamarin.Forms;
 
@@ -243,18 +244,47 @@ namespace Bit.iOS.Core.Services
             Device.OpenUri(new Uri(uri));
         }
 
-        public bool SupportsFaceId()
+        public bool SupportsFaceBiometric()
         {
             if(SystemMajorVersion() < 11)
             {
                 return false;
             }
-            var context = new LAContext();
+            using(var context = new LAContext())
-            if(!context.CanEvaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, out NSError e))
+            {
+                if(!context.CanEvaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, out var e))
+                {
+                    return false;
+                }
+                return context.BiometryType == LABiometryType.FaceId;
+            }
+        }
+
+        public Task<bool> SupportsFaceBiometricAsync()
+        {
+            return Task.FromResult(SupportsFaceBiometric());
+        }
+
+        public async Task<bool> BiometricAvailableAsync()
+        {
+            try
+            {
+                return await CrossFingerprint.Current.IsAvailableAsync();
+            }
+            catch
             {
                 return false;
             }
-            return context.BiometryType == LABiometryType.FaceId;
+        }
+
+        public bool UseNativeBiometric()
+        {
+            return false;
+        }
+
+        public Task<bool> AuthenticateBiometricAsync(string text = null)
+        {
+            throw new NotSupportedException();
         }
 
         public bool SupportsNfc()