[pve-devel] [PATCH pve-flutter-frontend 1/5] console: use flutter inappwebview as webview

[Dominik Csapak <d.csapak@proxmox.com>]

instead of flutter webview. This new dependency does not have the
limitations of the "official" flutter webview. We now can ignore
https errors and even get some info on the certificate.

We use that to now show a 'do you want to trust this cert' dialog with
the fingerprint of the server, which the user can then either trust or
abort.

When pressing yes, we save that fingerprint in the shared preferences so
that we don't have to ask the next time.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
this depends on the login-manager patch to add the 'trustedFingerprints' list

 lib/widgets/pve_console_menu_widget.dart | 128 ++++++++++++++++++++---
 pubspec.lock                             |  42 ++------
 pubspec.yaml                             |   3 +-
 3 files changed, 126 insertions(+), 47 deletions(-)

diff --git a/lib/widgets/pve_console_menu_widget.dart b/lib/widgets/pve_console_menu_widget.dart
index 767a51c..243baf1 100644
--- a/lib/widgets/pve_console_menu_widget.dart
+++ b/lib/widgets/pve_console_menu_widget.dart
@@ -6,7 +6,9 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:proxmox_dart_api_client/proxmox_dart_api_client.dart';
-import 'package:webview_flutter/webview_flutter.dart';
+import 'package:proxmox_login_manager/proxmox_general_settings_model.dart';
+import 'package:flutter_inappwebview/flutter_inappwebview.dart';
+import 'package:crypto/crypto.dart';
 
 class PveConsoleMenu extends StatelessWidget {
   static const platform =
@@ -104,8 +106,7 @@ class PveConsoleMenu extends StatelessWidget {
                   "noVNC Console", // xterm.js doesn't work that well on mobile
                   style: TextStyle(fontWeight: FontWeight.bold),
                 ),
-                subtitle: const Text(
-                    "Open console view (requires trusted SSL certificate)"),
+                subtitle: const Text("Open console view"),
                 onTap: () async {
                   if (Platform.isAndroid) {
                     if (['qemu', 'lxc'].contains(type)) {
@@ -209,6 +210,8 @@ class PVEWebConsole extends StatefulWidget {
 }
 
 class PVEWebConsoleState extends State<PVEWebConsole> {
+  InAppWebViewController? webViewController;
+
   @override
   Widget build(BuildContext context) {
     final ticket = widget.apiClient.credentials.ticket!;
@@ -222,24 +225,123 @@ class PVEWebConsoleState extends State<PVEWebConsole> {
     } else {
       consoleUrl += "&console=shell";
     }
-
-    final controller = WebViewController()
-      ..setJavaScriptMode(JavaScriptMode.unrestricted)
-      ..setBackgroundColor(Theme.of(context).colorScheme.background);
+    WidgetsFlutterBinding.ensureInitialized();
 
     return FutureBuilder(
-        future: WebViewCookieManager().setCookie(WebViewCookie(
+        future: CookieManager.instance().setCookie(
+          url: Uri.parse(consoleUrl),
           name: 'PVEAuthCookie',
           value: ticket,
-          domain: baseUrl.origin,
-        )),
+        ),
         builder: (context, snapshot) {
-          controller.loadRequest(Uri.parse(consoleUrl));
           return SafeArea(
-            child: WebViewWidget(
-              controller: controller,
+            child: InAppWebView(
+              onReceivedServerTrustAuthRequest: (controller, challenge) async {
+                final cert = challenge.protectionSpace.sslCertificate;
+                final certBytes = cert?.x509Certificate?.encoded;
+                final sslError = challenge.protectionSpace.sslError?.message;
+
+                String? issuedTo = cert?.issuedTo?.CName.toString();
+                String? hash = certBytes != null
+                    ? sha256.convert(certBytes).toString()
+                    : null;
+
+                final settings =
+                    await ProxmoxGeneralSettingsModel.fromLocalStorage();
+
+                bool trust = false;
+                if (hash != null && settings.trustedFingerprints != null) {
+                  trust = settings.trustedFingerprints!.contains(hash);
+                }
+
+                if (!trust) {
+                  // format hash to '01:23:...' format
+                  String? formattedHash = hash?.toUpperCase().replaceAllMapped(
+                      RegExp(r"[a-zA-Z0-9]{2}"),
+                      (match) => "${match.group(0)}:");
+                  formattedHash = formattedHash?.substring(
+                      0, formattedHash.length - 1); // remove last ':'
+
+                  if (context.mounted) {
+                    trust = await showTLSWarning(
+                        context,
+                        sslError ?? 'An unknown TLS error has occurred',
+                        issuedTo ?? 'unknown',
+                        formattedHash ?? 'unknown');
+                  }
+                }
+
+                // save Fingerprint
+                if (trust && hash != null) {
+                  await settings
+                      .rebuild((b) => b..trustedFingerprints.add(hash))
+                      .toLocalStorage();
+                  print(settings.toJson());
+                }
+
+                final action = trust
+                    ? ServerTrustAuthResponseAction.PROCEED
+                    : ServerTrustAuthResponseAction.CANCEL;
+                return ServerTrustAuthResponse(action: action);
+              },
+              onWebViewCreated: (controller) {
+                webViewController = controller;
+                controller.loadUrl(
+                    urlRequest: URLRequest(url: Uri.parse(consoleUrl)));
+              },
             ),
           );
         });
   }
+
+  Future<bool> showTLSWarning(BuildContext context, String sslError,
+      String issuedTo, String hash) async {
+    return await showDialog(
+        context: context,
+        barrierDismissible: false,
+        builder: (BuildContext context) {
+          return PopScope(
+            // prevent back button from canceling this callback
+            canPop: false,
+            child: AlertDialog(
+                title: const Text('An TLS error has occurred:'),
+                content: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    ListTile(
+                      title: const Text('Error Message:'),
+                      subtitle: Text(sslError),
+                    ),
+                    const ListTile(
+                      title: Text('Certificate Information:'),
+                    ),
+                    ListTile(
+                      title: const Text('Issued to:'),
+                      subtitle: Text(issuedTo),
+                    ),
+                    ListTile(
+                      title: const Text('Fingerprint:'),
+                      subtitle: Text(hash),
+                    ),
+                    const Text(''), // spacer
+                    const Text('Do you want to continue?'),
+                  ],
+                ),
+                actions: <Widget>[
+                  TextButton(
+                      onPressed: () {
+                        Navigator.of(context).pop(false);
+                        Navigator.of(context).pop();
+                      },
+                      child: const Text('No')),
+                  TextButton(
+                      onPressed: () {
+                        Navigator.of(context).pop(true);
+                      },
+                      child: const Text('Yes'))
+                ]),
+          );
+        });
+  }
 }
diff --git a/pubspec.lock b/pubspec.lock
index 7e39fba..94c0656 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -170,7 +170,7 @@ packages:
     source: hosted
     version: "3.1.1"
   crypto:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: crypto
       sha256: ff625774173754681d66daaf4a448684fb04b78f902da9cb3d308c19cc5e8bab
@@ -230,6 +230,14 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_inappwebview:
+    dependency: "direct main"
+    description:
+      name: flutter_inappwebview
+      sha256: d198297060d116b94048301ee6749cd2e7d03c1f2689783f52d210a6b7aba350
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.8.0"
   flutter_lints:
     dependency: "direct dev"
     description:
@@ -819,38 +827,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.4.5"
-  webview_flutter:
-    dependency: "direct main"
-    description:
-      name: webview_flutter
-      sha256: "25e1b6e839e8cbfbd708abc6f85ed09d1727e24e08e08c6b8590d7c65c9a8932"
-      url: "https://pub.dev"
-    source: hosted
-    version: "4.7.0"
-  webview_flutter_android:
-    dependency: transitive
-    description:
-      name: webview_flutter_android
-      sha256: f038ee2fae73b509dde1bc9d2c5a50ca92054282de17631a9a3d515883740934
-      url: "https://pub.dev"
-    source: hosted
-    version: "3.16.0"
-  webview_flutter_platform_interface:
-    dependency: transitive
-    description:
-      name: webview_flutter_platform_interface
-      sha256: d937581d6e558908d7ae3dc1989c4f87b786891ab47bb9df7de548a151779d8d
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.10.0"
-  webview_flutter_wkwebview:
-    dependency: transitive
-    description:
-      name: webview_flutter_wkwebview
-      sha256: f12f8d8a99784b863e8b85e4a9a5e3cf1839d6803d2c0c3e0533a8f3c5a992a7
-      url: "https://pub.dev"
-    source: hosted
-    version: "3.13.0"
   win32:
     dependency: transitive
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index 065749c..976dbb1 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -34,7 +34,6 @@ dependencies:
   url_launcher: ^6.0.17
   intl: ^0.19.0
   path_provider: ^2.0.8
-  webview_flutter: ^4.2.0
   proxmox_dart_api_client:
     path: ../proxmox_dart_api_client
   proxmox_login_manager:
@@ -42,6 +41,8 @@ dependencies:
   collection: ^1.15.0-nullsafety.4
 
   shared_preferences: any
+  flutter_inappwebview: ^5.8.0
+  crypto: ^3.0.3
 dev_dependencies:
   flutter_test:
     sdk: flutter
-- 
2.39.2