Improve sudo password interaction experience

v2rayN/v2rayN.Desktop/Views/StatusBarView.axaml.cs

@@ -104,13 +104,15 @@ public partial class StatusBarView : ReactiveUserControl<StatusBarViewModel>
     {
         var dialog = new SudoPasswordInputView();
         var obj = await DialogHost.Show(dialog);
-        if (obj == null)
+
+        var password = obj?.ToString();
+        if (password.IsNullOrEmpty())
         {
             togEnableTun.IsChecked = false;
             return false;
         }
 
-        AppHandler.Instance.LinuxSudoPwd = obj.ToString() ?? string.Empty;
+        AppHandler.Instance.LinuxSudoPwd = password;
         return true;
     }
 

v2rayN/v2rayN.Desktop/Views/SudoPasswordInputView.axaml.cs

@@ -1,5 +1,6 @@
 using Avalonia.Controls;
 using Avalonia.Threading;
+using CliWrap.Buffered;
 using DialogHostAvalonia;
 
 namespace v2rayN.Desktop.Views;
@@ -12,22 +13,71 @@ public partial class SudoPasswordInputView : UserControl
 
         this.Loaded += (s, e) => txtPassword.Focus();
 
-        btnSave.Click += (_, _) =>
-        {
-            if (string.IsNullOrEmpty(txtPassword.Text))
-            {
-                txtPassword.Focus();
-                return;
-            }
-            Dispatcher.UIThread.Post(() =>
-            {
-                DialogHost.Close(null, txtPassword.Text);
-            });
-        };
+        btnSave.Click += async (_, _) => await SavePasswordAsync();
 
         btnCancel.Click += (_, _) =>
         {
             DialogHost.Close(null);
         };
     }
+
+    private async Task SavePasswordAsync()
+    {
+        if (txtPassword.Text.IsNullOrEmpty())
+        {
+            txtPassword.Focus();
+            return;
+        }
+
+        var password = txtPassword.Text;
+        btnSave.IsEnabled = false;
+
+        try
+        {
+            // Verify if the password is correct
+            if (await CheckSudoPasswordAsync(password))
+            {
+                // Password verification successful, return password and close dialog
+                await Dispatcher.UIThread.InvokeAsync(() =>
+                {
+                    DialogHost.Close(null, password);
+                });
+            }
+            else
+            {
+                // Password verification failed, display error and let user try again
+                NoticeHandler.Instance.Enqueue(ResUI.SudoIncorrectPasswordTip);
+                txtPassword.Focus();
+            }
+        }
+        catch (Exception ex)
+        {
+            Logging.SaveLog("SudoPassword", ex);
+        }
+        finally
+        {
+            btnSave.IsEnabled = true;
+        }
+    }
+
+    private async Task<bool> CheckSudoPasswordAsync(string password)
+    {
+        try
+        {
+            // Use sudo -S echo command to verify password
+            var arg = new List<string>() { "-c", "sudo -S echo SUDO_CHECK" };
+            var result = await CliWrap.Cli
+                .Wrap(Global.LinuxBash)
+                .WithArguments(arg)
+                .WithStandardInputPipe(CliWrap.PipeSource.FromString(password))
+                .ExecuteBufferedAsync();
+
+            return result.ExitCode == 0;
+        }
+        catch (Exception ex)
+        {
+            Logging.SaveLog("CheckSudoPassword", ex);
+            return false;
+        }
+    }
 }