Add password support for protected certificates

Introduces UI and logic to handle password-protected certificate files. The CertViewerControl now prompts for a password if needed, and attempts to reload the certificate with the provided password. Refactored certificate loading flow to support this feature.

QuickLook.Plugin/QuickLook.Plugin.CertViewer/CertLoadResult.cs

@@ -8,15 +8,17 @@ internal sealed class CertLoadResult
     public X509Certificate2 Certificate { get; }
     public string Message { get; }
     public string RawContent { get; }
+    public bool NeedsPassword { get; }
 
-    public CertLoadResult(bool success, X509Certificate2 certificate, string message, string rawContent)
+    public CertLoadResult(bool success, X509Certificate2 certificate, string message, string rawContent, bool needsPassword = false)
     {
         Success = success;
         Certificate = certificate;
         Message = message;
         RawContent = rawContent;
+        NeedsPassword = needsPassword;
     }
 
-    public static CertLoadResult From(bool success, X509Certificate2 certificate, string message, string rawContent)
-        => new CertLoadResult(success, certificate, message, rawContent);
+    public static CertLoadResult From(bool success, X509Certificate2 certificate, string message, string rawContent, bool needsPassword = false)
+        => new CertLoadResult(success, certificate, message, rawContent, needsPassword);
 }

QuickLook.Plugin/QuickLook.Plugin.CertViewer/CertUtils.cs

@@ -14,7 +14,7 @@ internal static class CertUtils
     /// - Message: an informational or error message
     /// - RawContent: original file text or hex when parsing failed
     /// </summary>
-    public static CertLoadResult TryLoadCertificate(string path)
+    public static CertLoadResult TryLoadCertificate(string path, string password = null)
     {
         try
         {
@@ -24,12 +24,16 @@ internal static class CertUtils
             {
                 try
                 {
-                    var cert = new X509Certificate2(path);
+                    var cert = !string.IsNullOrEmpty(password)
+                        ? new X509Certificate2(path, password)
+                        : new X509Certificate2(path);
                     return new CertLoadResult(true, cert, string.Empty, null);
                 }
                 catch (Exception ex)
                 {
-                    return new CertLoadResult(false, null, "Failed to load PFX/P12: " + ex.Message, null);
+                    var isPasswordError = ex is System.Security.Cryptography.CryptographicException ||
+                                          (ex.Message?.IndexOf("password", StringComparison.OrdinalIgnoreCase) >= 0);
+                    return new CertLoadResult(false, null, "Failed to load PFX/P12: " + ex.Message, null, isPasswordError);
                 }
             }
 

QuickLook.Plugin/QuickLook.Plugin.CertViewer/CertViewerControl.xaml

@@ -12,29 +12,41 @@
             <ColumnDefinition Width="*" />
         </Grid.ColumnDefinitions>
         <Grid.RowDefinitions>
+            <RowDefinition Height="Auto" />
             <RowDefinition Height="*" />
         </Grid.RowDefinitions>
 
-        <DataGrid x:Name="PropertyList"
-                  Grid.Column="0"
-                  Margin="8"
-                  AutoGenerateColumns="False"
-                  IsReadOnly="True"
-                  HeadersVisibility="Column"
-                  RowHeaderWidth="0">
-            <DataGrid.Columns>
-                <DataGridTextColumn Header="Field" Binding="{Binding Key}" Width="150" />
-                <DataGridTextColumn Header="Value" Binding="{Binding Value}" Width="*" />
-            </DataGrid.Columns>
-        </DataGrid>
+        <!-- Password panel (hidden by default) -->
+        <StackPanel x:Name="PasswordPanel" Grid.Row="0" Grid.ColumnSpan="2" Orientation="Horizontal" Margin="8" Visibility="Collapsed" VerticalAlignment="Center">
+            <TextBlock Text="This certificate appears to be password-protected. Enter password:" VerticalAlignment="Center" Margin="0,0,8,0" />
+            <PasswordBox x:Name="InlinePasswordBox" Width="220" Margin="0,0,8,0" />
+            <Button x:Name="LoadWithPasswordButton" Content="Load" Width="80" Margin="0,0,8,0" Click="LoadWithPasswordButton_Click" />
+            <Button x:Name="CancelPasswordButton" Content="Cancel" Width="80" Click="CancelPasswordButton_Click" />
+        </StackPanel>
 
-        <TextBox x:Name="RawText"
-                 Grid.Column="1"
-                 Margin="8"
-                 AcceptsReturn="True"
-                 HorizontalScrollBarVisibility="Auto"
-                 IsReadOnly="True"
-                 TextWrapping="Wrap"
-                 VerticalScrollBarVisibility="Auto" />
+        <TabControl Grid.Row="1" Grid.ColumnSpan="2" Margin="8">
+            <TabItem Header="Details">
+                <DataGrid x:Name="PropertyList"
+                          AutoGenerateColumns="False"
+                          IsReadOnly="True"
+                          HeadersVisibility="Column"
+                          RowHeaderWidth="0"
+                          Margin="0">
+                    <DataGrid.Columns>
+                        <DataGridTextColumn Header="Field" Binding="{Binding Key}" Width="150" />
+                        <DataGridTextColumn Header="Value" Binding="{Binding Value}" Width="*" />
+                    </DataGrid.Columns>
+                </DataGrid>
+            </TabItem>
+            <TabItem Header="Raw">
+                <TextBox x:Name="RawText"
+                         AcceptsReturn="True"
+                         HorizontalScrollBarVisibility="Auto"
+                         IsReadOnly="True"
+                         TextWrapping="Wrap"
+                         VerticalScrollBarVisibility="Auto"
+                         Margin="0" />
+            </TabItem>
+        </TabControl>
     </Grid>
 </UserControl>

QuickLook.Plugin/QuickLook.Plugin.CertViewer/CertViewerControl.xaml.cs

@@ -7,13 +7,43 @@ namespace QuickLook.Plugin.CertViewer;
 
 public partial class CertViewerControl : UserControl, IDisposable
 {
+    private string _currentPath;
+
     public CertViewerControl()
     {
         InitializeComponent();
     }
 
+    /// <summary>
+    /// Load a certificate file from path. If the file appears password-protected,
+    /// the control will show an inline password input and allow the user to retry.
+    /// </summary>
+    public void LoadFromPath(string path)
+    {
+        _currentPath = path;
+
+        var result = CertUtils.TryLoadCertificate(path);
+
+        if (!result.Success && result.NeedsPassword)
+        {
+            // show password UI
+            PasswordPanel.Visibility = System.Windows.Visibility.Visible;
+            PropertyList.ItemsSource = null;
+            RawText.Text = string.Empty;
+            return;
+        }
+
+        PasswordPanel.Visibility = System.Windows.Visibility.Collapsed;
+
+        if (result.Success && result.Certificate != null)
+            LoadCertificate(result.Certificate);
+        else
+            LoadRaw(path, result.Message, result.RawContent);
+    }
+
     public void LoadCertificate(X509Certificate2 cert)
     {
+        PasswordPanel.Visibility = System.Windows.Visibility.Collapsed;
         var items = new List<KeyValuePair<string, string>>
         {
             new("Subject", cert.Subject),
@@ -32,6 +62,7 @@ public partial class CertViewerControl : UserControl, IDisposable
 
     public void LoadRaw(string path, string message, string content)
     {
+        PasswordPanel.Visibility = System.Windows.Visibility.Collapsed;
         PropertyList.ItemsSource = new List<KeyValuePair<string, string>>
         {
             new("Path", path),
@@ -44,4 +75,34 @@ public partial class CertViewerControl : UserControl, IDisposable
     public void Dispose()
     {
     }
+
+    private void LoadWithPasswordButton_Click(object sender, System.Windows.RoutedEventArgs e)
+    {
+        var pwd = InlinePasswordBox.Password;
+        if (string.IsNullOrEmpty(_currentPath))
+            return;
+
+        var result = CertUtils.TryLoadCertificate(_currentPath, pwd);
+        PasswordPanel.Visibility = System.Windows.Visibility.Collapsed;
+
+        if (result.Success && result.Certificate != null)
+        {
+            LoadCertificate(result.Certificate);
+        }
+        else
+        {
+            LoadRaw(_currentPath, result.Message, result.RawContent);
+        }
+    }
+
+    private void CancelPasswordButton_Click(object sender, System.Windows.RoutedEventArgs e)
+    {
+        // show failure/raw view
+        if (string.IsNullOrEmpty(_currentPath))
+            return;
+
+        var result = CertUtils.TryLoadCertificate(_currentPath);
+        PasswordPanel.Visibility = System.Windows.Visibility.Collapsed;
+        LoadRaw(_currentPath, result.Message, result.RawContent);
+    }
 }

QuickLook.Plugin/QuickLook.Plugin.CertViewer/Plugin.cs

@@ -56,18 +56,8 @@ public class Plugin : IViewer
 
         context.IsBusy = true;
 
-        var result = CertUtils.TryLoadCertificate(path);
-
         _control = new CertViewerControl();
-
-        if (result.Success && result.Certificate != null)
-        {
-            _control.LoadCertificate(result.Certificate);
-        }
-        else
-        {
-            _control.LoadRaw(path, result.Message, result.RawContent);
-        }
+        _control.LoadFromPath(path);
 
         context.ViewerContent = _control;
         context.Title = Path.GetFileName(path);