[iOS Only] Support Passcode Fallback Natively

README.md

@@ -59,7 +59,7 @@ There's excellent documentation on how to do this in the [React Native Docs](htt
 
 iOS and Android differ slightly in their TouchID authentication.
 
-On Android you can customize the title and color of the pop-up by passing in the **optional config object** with a color and title key to the `authenticate` method. Even if you pass in the config object, iOS **does not** allow you change the color nor the title of the pop-up.
+On Android you can customize the title and color of the pop-up by passing in the **optional config object** with a color and title key to the `authenticate` method. Even if you pass in the config object, iOS **does not** allow you change the color nor the title of the pop-up. iOS does support `passcodeFallback` as an option, which when set to `true` will allow users to use their device pin - useful for people with Face / Touch ID disabled.
 
 Error handling is also different between the platforms, with iOS currently providing much more descriptive error codes.
 
@@ -151,6 +151,7 @@ __Arguments__
   - `cancelText` - **Android** - cancel button text
   - `fallbackLabel` - **iOS** - by default specified 'Show Password' label. If set to empty string label is invisible.
   - `unifiedErrors` - return unified error messages (see below) (default = false)
+  - `passcodeFallback` - **iOS** - by default set to false. If set to true, will allow use of keypad passcode.
 
 
 __Examples__
@@ -161,7 +162,8 @@ const optionalConfigObject = {
   sensorDescription: "Touch sensor", // Android
   cancelText: "Cancel", // Android
   fallbackLabel: "Show Passcode", // iOS (if empty, then label is hidden)
-  unifiedErrors: false // use unified error messages (default false)
+  unifiedErrors: false, // use unified error messages (default false)
+  passcodeFallback: false // iOS
 }
 
 TouchID.authenticate('to demo this react-native component', optionalConfigObject)

TouchID.ios.js

@@ -29,7 +29,8 @@ export default {
   authenticate(reason, config) {
     const DEFAULT_CONFIG = {
       fallbackLabel: null,
-      unifiedErrors: false
+      unifiedErrors: false,
+      passcodeFallback: false
     };
     const authReason = reason ? reason : ' ';
     const authConfig = Object.assign({}, DEFAULT_CONFIG, config);

TouchID.m

@@ -13,8 +13,12 @@ @implementation TouchID
 
     if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {
         callback(@[[NSNull null], [self getBiometryType:context]]);
-        // Device does not support TouchID
-    } else {
+
+    } else if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthentication error:&error]) {
+        callback(@[[NSNull null], [self getBiometryType:context]]);
+    }
+    // Device does not support FaceID / TouchID / Pin
+    else {
         callback(@[RCTMakeError(@"RCTTouchIDNotSupported", nil, nil)]);
         return;
     }
@@ -24,6 +28,7 @@ @implementation TouchID
                   options:(NSDictionary *)options
                   callback: (RCTResponseSenderBlock)callback)
 {
+    NSNumber *passcodeFallback = [NSNumber numberWithBool:false];
     LAContext *context = [[LAContext alloc] init];
     NSError *error;
 
@@ -32,75 +37,98 @@ @implementation TouchID
         context.localizedFallbackTitle = fallbackLabel;
     }
 
+    if (RCTNilIfNull([options objectForKey:@"passcodeFallback"]) != nil) {
+        passcodeFallback = [RCTConvert NSNumber:options[@"passcodeFallback"]];
+    }
+
     // Device has TouchID
     if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {
         // Attempt Authentification
         [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
                 localizedReason:reason
                           reply:^(BOOL success, NSError *error)
          {
-             if (success) { // Authentication Successful
-                 callback(@[[NSNull null], @"Authenticated with Touch ID."]);
-             } else if (error) { // Authentication Error
-                 NSString *errorReason;
-
-                 switch (error.code) {
-                     case LAErrorAuthenticationFailed:
-                         errorReason = @"LAErrorAuthenticationFailed";
-                         break;
-
-                     case LAErrorUserCancel:
-                         errorReason = @"LAErrorUserCancel";
-                         break;
-
-                     case LAErrorUserFallback:
-                         errorReason = @"LAErrorUserFallback";
-                         break;
-
-                     case LAErrorSystemCancel:
-                         errorReason = @"LAErrorSystemCancel";
-                         break;
-
-                     case LAErrorPasscodeNotSet:
-                         errorReason = @"LAErrorPasscodeNotSet";
-                         break;
-
-                     case LAErrorTouchIDNotAvailable:
-                         errorReason = @"LAErrorTouchIDNotAvailable";
-                         break;
-
-                     case LAErrorTouchIDNotEnrolled:
-                         errorReason = @"LAErrorTouchIDNotEnrolled";
-                         break;
-
-                     default:
-                         errorReason = @"RCTTouchIDUnknownError";
-                         break;
-                 }
-
-                 NSLog(@"Authentication failed: %@", errorReason);
-                 callback(@[RCTMakeError(errorReason, nil, nil)]);
-             } else { // Authentication Failure
-                 callback(@[RCTMakeError(@"LAErrorAuthenticationFailed", nil, nil)]);
-             }
+             [self handleAttemptToUseDeviceIDWithSuccess:success error:error callback:callback];
          }];
 
-        // Device does not support TouchID
-    } else {
+        // Device does not support TouchID but user wishes to use passcode fallback
+    } else if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthentication error:&error] && [passcodeFallback boolValue]) {
+        // Attempt Authentification
+        [context evaluatePolicy:LAPolicyDeviceOwnerAuthentication
+                localizedReason:reason
+                          reply:^(BOOL success, NSError *error)
+         {
+             [self handleAttemptToUseDeviceIDWithSuccess:success error:error callback:callback];
+         }];
+    }
+    else {
         callback(@[RCTMakeError(@"RCTTouchIDNotSupported", nil, nil)]);
         return;
     }
 }
 
+- (void)handleAttemptToUseDeviceIDWithSuccess:(BOOL)success error:(NSError *)error callback:(RCTResponseSenderBlock)callback {
+    if (success) { // Authentication Successful
+        callback(@[[NSNull null], @"Authenticated with Touch ID."]);
+    } else if (error) { // Authentication Error
+        NSString *errorReason;
+
+        switch (error.code) {
+            case LAErrorAuthenticationFailed:
+                errorReason = @"LAErrorAuthenticationFailed";
+                break;
+
+            case LAErrorUserCancel:
+                errorReason = @"LAErrorUserCancel";
+                break;
+
+            case LAErrorUserFallback:
+                errorReason = @"LAErrorUserFallback";
+                break;
+
+            case LAErrorSystemCancel:
+                errorReason = @"LAErrorSystemCancel";
+                break;
+
+            case LAErrorPasscodeNotSet:
+                errorReason = @"LAErrorPasscodeNotSet";
+                break;
+
+            case LAErrorTouchIDNotAvailable:
+                errorReason = @"LAErrorTouchIDNotAvailable";
+                break;
+
+            case LAErrorTouchIDNotEnrolled:
+                errorReason = @"LAErrorTouchIDNotEnrolled";
+                break;
+
+            default:
+                errorReason = @"RCTTouchIDUnknownError";
+                break;
+        }
+
+        NSLog(@"Authentication failed: %@", errorReason);
+        callback(@[RCTMakeError(errorReason, nil, nil)]);
+    } else { // Authentication Failure
+        callback(@[RCTMakeError(@"LAErrorAuthenticationFailed", nil, nil)]);
+    }
+}
+
 - (NSString *)getBiometryType:(LAContext *)context
 {
     if (@available(iOS 11, *)) {
-        return (context.biometryType == LABiometryTypeFaceID) ? @"FaceID" : @"TouchID";
+        if (context.biometryType == LABiometryTypeFaceID) {
+            return @"FaceID";
+        }
+        else if (context.biometryType == LABiometryTypeTouchID) {
+            return @"TouchID";
+        }
+        else if (context.biometryType == LABiometryNone) {
+            return @"None";
+        }
     }
 
     return @"TouchID";
 }
 
 @end
-
-