add proper check for valid qr code to prevent 500s

verification/ios/Podfile.lock

@@ -14,7 +14,7 @@ PODS:
   - Reachability (3.2)
   - shared_preferences_ios (0.0.1):
     - Flutter
-  - url_launcher (0.0.1):
+  - url_launcher_ios (0.0.1):
     - Flutter
 
 DEPENDENCIES:
@@ -24,7 +24,7 @@ DEPENDENCIES:
   - path_provider_ios (from `.symlinks/plugins/path_provider_ios/ios`)
   - qr_code_scanner (from `.symlinks/plugins/qr_code_scanner/ios`)
   - shared_preferences_ios (from `.symlinks/plugins/shared_preferences_ios/ios`)
-  - url_launcher (from `.symlinks/plugins/url_launcher/ios`)
+  - url_launcher_ios (from `.symlinks/plugins/url_launcher_ios/ios`)
 
 SPEC REPOS:
   trunk:
@@ -44,8 +44,8 @@ EXTERNAL SOURCES:
     :path: ".symlinks/plugins/qr_code_scanner/ios"
   shared_preferences_ios:
     :path: ".symlinks/plugins/shared_preferences_ios/ios"
-  url_launcher:
-    :path: ".symlinks/plugins/url_launcher/ios"
+  url_launcher_ios:
+    :path: ".symlinks/plugins/url_launcher_ios/ios"
 
 SPEC CHECKSUMS:
   connectivity: c4130b2985d4ef6fd26f9702e886bd5260681467
@@ -56,8 +56,8 @@ SPEC CHECKSUMS:
   qr_code_scanner: bb67d64904c3b9658ada8c402e8b4d406d5d796e
   Reachability: 33e18b67625424e47b6cde6d202dce689ad7af96
   shared_preferences_ios: aef470a42dc4675a1cdd50e3158b42e3d1232b32
-  url_launcher: b6e016d912f04be9f5bf6e8e82dc599b7ba59649
+  url_launcher_ios: 02f1989d4e14e998335b02b67a7590fa34f971af
 
 PODFILE CHECKSUM: aafe91acc616949ddb318b77800a7f51bffa2a4c
 
-COCOAPODS: 1.10.0
+COCOAPODS: 1.11.2

verification/lib/home_page.dart

 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
+import 'dart:typed_data';
 
 import 'package:connectivity/connectivity.dart';
 import 'package:digital_3g_common/backend_switcher.dart';
@@ -468,6 +470,13 @@ class _HomePageState extends State<HomePage> {
     controller.scannedDataStream.listen((scanData) {
       if ((scanData.code?.isNotEmpty ?? false) && !_disconnected) {
         if (_lastResult != scanData.code) {
+          // check for valid base64 or else cancel
+          try {
+            final Uint8List decoded = base64.decode(scanData.code!);
+            if (decoded.isEmpty) return;
+          } catch (e) {
+            return;
+          }
           _qrResult = scanData;
           _lastResult = _qrResult!.code!;
           _bloc!.onAdd(_lastResult);

verification/lib/verification_bloc.dart

@@ -52,9 +52,10 @@ class VerificationBloc extends Bloc<VerificationEvent, VerificationState> {
             _verification = response;
             await _verificationStore!.writeAsString(json.encode(_verification!.toMap));
             yield VerificationState.verified;
-          } else if ((((await Connectivity().checkConnectivity()) == ConnectivityResult.none) &&
-                  (_verificationStore?.existsSync() ?? false)) ||
-              ((response?.hasError ?? false) && response!.error == VerificationErrorType.server)) {
+          } else if (((((await Connectivity().checkConnectivity()) == ConnectivityResult.none) ||
+                  ((response?.hasError ?? false) &&
+                      response!.error == VerificationErrorType.server)) &&
+              (_verificationStore?.existsSync() ?? false))) {
             // get verification from local storage
             final loaded =
                 VerificationResponse.fromMap(json.decode(await _verificationStore!.readAsString()));

verification/pubspec.lock

@@ -213,7 +213,7 @@ packages:
       name: path_provider_android
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.0.9"
   path_provider_ios:
     dependency: transitive
     description:
@@ -234,7 +234,7 @@ packages:
       name: path_provider_macos
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.3"
+    version: "2.0.4"
   path_provider_platform_interface:
     dependency: transitive
     description:
@@ -255,7 +255,7 @@ packages:
       name: platform
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.2"
+    version: "3.1.0"
   plugin_platform_interface:
     dependency: transitive
     description:
@@ -297,7 +297,7 @@ packages:
       name: shared_preferences_android
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.0.9"
   shared_preferences_ios:
     dependency: transitive
     description:
@@ -379,7 +379,21 @@ packages:
       name: url_launcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "6.0.15"
+    version: "6.0.17"
+  url_launcher_android:
+    dependency: transitive
+    description:
+      name: url_launcher_android
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "6.0.13"
+  url_launcher_ios:
+    dependency: transitive
+    description:
+      name: url_launcher_ios
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "6.0.13"
   url_launcher_linux:
     dependency: transitive
     description:
@@ -407,7 +421,7 @@ packages:
       name: url_launcher_web
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.4"
+    version: "2.0.5"
   url_launcher_windows:
     dependency: transitive
     description:
@@ -428,7 +442,7 @@ packages:
       name: win32
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.3.0"
+    version: "2.3.1"
   xdg_directories:
     dependency: transitive
     description: