From 2b3915a91fa87219b0df92388166c7b0a0e2dfe3 Mon Sep 17 00:00:00 2001
From: Chris <watk@users.noreply.github.com>
Date: Fri, 24 Apr 2020 00:28:43 +1000
Subject: [PATCH] Allow a BiometricPrompt to succeed after an initial failure
 (#791) (#847)

Previously a call to BiometricPrompt.AuthenticationCallback#OnAuthenticationFailed()
was treated as though an unrecoverable failure had occurred. However this is called on
each failed fingerprint match, for example, and is not a terminal failure. Now these
intermittent failures are ignored and a call to #OnAuthenticationError() is recognised
as an unrecoverable failure instead.
---
 src/Android/Services/DeviceActionService.cs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/Android/Services/DeviceActionService.cs b/src/Android/Services/DeviceActionService.cs
index 02cee112a..78390e741 100644
--- a/src/Android/Services/DeviceActionService.cs
+++ b/src/Android/Services/DeviceActionService.cs
@@ -446,7 +446,8 @@ namespace Bit.Droid.Services
                     new BiometricAuthenticationCallback
                     {
                         Success = authResult => result.TrySetResult(true),
-                        Failed = () => result.TrySetResult(false),
+                        Error = () => result.TrySetResult(false),
+                        Failed = () => { },
                         Help = (helpCode, helpString) => { }
                     });
                 return result.Task;
@@ -866,6 +867,7 @@ namespace Bit.Droid.Services
         private class BiometricAuthenticationCallback : BiometricPrompt.AuthenticationCallback
         {
             public Action<BiometricPrompt.AuthenticationResult> Success { get; set; }
+            public Action Error { get; set; }
             public Action Failed { get; set; }
             public Action<BiometricAcquiredStatus, Java.Lang.ICharSequence> Help { get; set; }
 
@@ -875,6 +877,12 @@ namespace Bit.Droid.Services
                 Success?.Invoke(authResult);
             }
 
+            public override void OnAuthenticationError([GeneratedEnum] BiometricErrorCode errorCode, Java.Lang.ICharSequence errString)
+            {
+                base.OnAuthenticationError(errorCode, errString);
+                Error?.Invoke();
+            }
+
             public override void OnAuthenticationFailed()
             {
                 base.OnAuthenticationFailed();