Add passphrase-protected private key support

Wire up QOpcUaClient::passwordForPrivateKeyRequired to a QML dialog,
mirroring the existing certificate trust flow (local QEventLoop + 30s
timeout).

3 files changed, 66 insertions, 0 deletions

diff --git a/demo/CMakeLists.txt b/demo/CMakeLists.txt
index 96dade8..ca39de8 100644
--- a/demo/CMakeLists.txt
+++ b/demo/CMakeLists.txt
@@ -9,6 +9,7 @@ qt_add_qml_module(
   QML_FILES
   Main.qml
   CertTrustDialog.qml
+  KeyPasswordDialog.qml
   ConnectionPage.qml
   DebugConsole.qml
   NodePage.qml
diff --git a/demo/KeyPasswordDialog.qml b/demo/KeyPasswordDialog.qml
new file mode 100644
index 0000000..4bf094c
--- /dev/null
+++ b/demo/KeyPasswordDialog.qml
@@ -0,0 +1,53 @@
+// KeyPasswordDialog.qml — Modal dialog for encrypted private-key passphrase.
+
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+import Bobink
+
+Dialog {
+    id: keyPasswordDialog
+
+    property string keyFilePath
+    property bool previousTryWasInvalid: false
+
+    anchors.centerIn: parent
+    implicitWidth: 400
+    modal: true
+    standardButtons: Dialog.Ok | Dialog.Cancel
+    title: "Private Key Password"
+
+    onAccepted: Bobink.provideKeyPassword(passwordField.text)
+    onOpened: {
+        passwordField.text = "";
+        passwordField.forceActiveFocus();
+    }
+    onRejected: Bobink.cancelKeyPassword()
+
+    ColumnLayout {
+        width: parent.width
+
+        Label {
+            Layout.fillWidth: true
+            text: "Enter the password for:\n" + keyPasswordDialog.keyFilePath
+            wrapMode: Text.Wrap
+        }
+
+        Label {
+            Layout.fillWidth: true
+            color: "red"
+            text: "Invalid password, please try again."
+            visible: keyPasswordDialog.previousTryWasInvalid
+        }
+
+        TextField {
+            id: passwordField
+
+            Layout.fillWidth: true
+            echoMode: TextInput.Password
+            placeholderText: "Password"
+
+            onAccepted: keyPasswordDialog.accept()
+        }
+    }
+}
diff --git a/demo/Main.qml b/demo/Main.qml
index 908dcbd..f0f3674 100644
--- a/demo/Main.qml
+++ b/demo/Main.qml
@@ -44,6 +44,13 @@ ApplicationWindow {
             debugConsole.appendLog("Discovering: " + Bobink.discovering);
         }
 
+        function onPrivateKeyPasswordRequired(keyFilePath,
+                                              previousTryWasInvalid) {
+            keyPasswordDialog.keyFilePath = keyFilePath;
+            keyPasswordDialog.previousTryWasInvalid = previousTryWasInvalid;
+            keyPasswordDialog.open();
+        }
+
         function onServersChanged() {
             debugConsole.appendLog("Discovered server list updated");
         }
@@ -60,6 +67,11 @@ ApplicationWindow {
 
     }
 
+    KeyPasswordDialog {
+        id: keyPasswordDialog
+
+    }
+
     ColumnLayout {
         anchors.fill: parent
         spacing: 0