From 9529c1621520750a8bee98e2058147cd399e655b Mon Sep 17 00:00:00 2001
From: Gokul Kulkarni <gokul.cs5@gmail.com>
Date: Tue, 5 Sep 2023 01:08:31 +0530
Subject: [PATCH] Added fallback mechanism for android

---
 KeychainExample/App.js                        | 23 ++++++++++++++++++-
 .../com/oblador/keychain/KeychainModule.java  | 14 ++++++++++-
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/KeychainExample/App.js b/KeychainExample/App.js
index f61c5ad6..5d1acae0 100644
--- a/KeychainExample/App.js
+++ b/KeychainExample/App.js
@@ -13,7 +13,7 @@ import SegmentedControlTab from 'react-native-segmented-control-tab';
 import * as Keychain from 'react-native-keychain';
 
 const ACCESS_CONTROL_OPTIONS = ['None', 'Passcode', 'Password'];
-const ACCESS_CONTROL_OPTIONS_ANDROID = ['None'];
+const ACCESS_CONTROL_OPTIONS_ANDROID = ['None', 'Fallback'];
 const ACCESS_CONTROL_MAP = [
   null,
   Keychain.ACCESS_CONTROL.DEVICE_PASSCODE,
@@ -22,6 +22,7 @@ const ACCESS_CONTROL_MAP = [
 ];
 const ACCESS_CONTROL_MAP_ANDROID = [
   null,
+  Keychain.ACCESS_CONTROL.BIOMETRY_ANY_OR_DEVICE_PASSCODE,
   Keychain.ACCESS_CONTROL.BIOMETRY_CURRENT_SET,
 ];
 const SECURITY_LEVEL_OPTIONS = ['Any', 'Software', 'Hardware'];
@@ -39,6 +40,13 @@ const SECURITY_STORAGE_MAP = [
   Keychain.STORAGE_TYPE.RSA,
 ];
 
+const ACCESS_CTRL_TO_AUTH_TYPE = {
+  [Keychain.ACCESS_CONTROL.BIOMETRY_ANY]:
+    Keychain.AUTHENTICATION_TYPE.BIOMETRICS,
+  [Keychain.ACCESS_CONTROL.BIOMETRY_ANY_OR_DEVICE_PASSCODE]:
+    Keychain.AUTHENTICATION_TYPE.DEVICE_PASSCODE_OR_BIOMETRICS,
+};
+
 export default class KeychainExample extends Component {
   state = {
     username: '',
@@ -94,6 +102,18 @@ export default class KeychainExample extends Component {
           cancel: 'Cancel',
         },
       };
+      if (this.state.accessControl) {
+        options.authenticationType =
+          ACCESS_CTRL_TO_AUTH_TYPE[this.state.accessControl];
+        options.accessControl = this.state.accessControl;
+      }
+      if (
+        Platform.OS === 'android' &&
+        options.authenticationType ===
+          Keychain.AUTHENTICATION_TYPE.DEVICE_PASSCODE_OR_BIOMETRICS
+      ) {
+        options.authenticationPrompt.cancel = '';
+      }
       const credentials = await Keychain.getGenericPassword(options);
       if (credentials) {
         this.setState({ ...credentials, status: 'Credentials loaded!' });
@@ -340,6 +360,7 @@ const styles = StyleSheet.create({
     fontWeight: '500',
     fontSize: 15,
     marginBottom: 5,
+    color: 'black',
   },
   input: {
     color: '#000',
diff --git a/android/src/main/java/com/oblador/keychain/KeychainModule.java b/android/src/main/java/com/oblador/keychain/KeychainModule.java
index 9413000c..49de09e6 100644
--- a/android/src/main/java/com/oblador/keychain/KeychainModule.java
+++ b/android/src/main/java/com/oblador/keychain/KeychainModule.java
@@ -52,6 +52,7 @@ public class KeychainModule extends ReactContextBaseJavaModule {
   public static final String IRIS_SUPPORTED_NAME = "Iris";
   public static final String EMPTY_STRING = "";
   public static final String WARMING_UP_ALIAS = "warmingUp";
+  public static final String AUTHENTICATION_TYPE = "authenticationType";
 
   private static final String LOG_TAG = KeychainModule.class.getSimpleName();
 
@@ -74,6 +75,13 @@ public class KeychainModule extends ReactContextBaseJavaModule {
     String BIOMETRY_CURRENT_SET_OR_DEVICE_PASSCODE = "BiometryCurrentSetOrDevicePasscode";
   }
 
+  @StringDef({AuthenticateType.BIOMETRICS
+  , AuthenticateType.DEVICE_PASSCODE_OR_BIOMETRICS})
+  @interface AuthenticateType {
+    String DEVICE_PASSCODE_OR_BIOMETRICS = "AuthenticationWithBiometricsDevicePasscode";
+    String BIOMETRICS = "AuthenticationWithBiometrics";
+  }
+
   @interface AuthPromptOptions {
     String TITLE = "title";
     String SUBTITLE = "subtitle";
@@ -618,7 +626,11 @@ private static PromptInfo getPromptInfo(@Nullable final ReadableMap options) {
     }
 
     /* PromptInfo is only used in Biometric-enabled RSA storage and can only be unlocked by a strong biometric */
-    promptInfoBuilder.setAllowedAuthenticators(BiometricManager.Authenticators.BIOMETRIC_STRONG);
+    int allowedAuthenticators = BiometricManager.Authenticators.BIOMETRIC_STRONG;
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R && options.hasKey(AUTHENTICATION_TYPE) && options.getString(AUTHENTICATION_TYPE).equals(AuthenticateType.DEVICE_PASSCODE_OR_BIOMETRICS)) {
+      allowedAuthenticators = BiometricManager.Authenticators.BIOMETRIC_STRONG | BiometricManager.Authenticators.DEVICE_CREDENTIAL;
+    }
+    promptInfoBuilder.setAllowedAuthenticators(allowedAuthenticators);
 
     /* Bypass confirmation to avoid KeyStore unlock timeout being exceeded when using passive biometrics */
     promptInfoBuilder.setConfirmationRequired(false);