Public key encryption: initiate new security handler

Pdf4QtViewer/pdfencryptionsettingsdialog.cpp

@@ -21,6 +21,7 @@
 #include "pdfutils.h"
 #include "pdfwidgetutils.h"
 #include "pdfsecurityhandler.h"
+#include "pdfcertificatemanager.h"
 #include "pdfdbgheap.h"
 
 #include <QMessageBox>
@@ -40,6 +41,7 @@ PDFEncryptionSettingsDialog::PDFEncryptionSettingsDialog(QByteArray documentId,
     ui->algorithmComboBox->addItem(tr("RC4 128-bit | R4"), int(pdf::PDFSecurityHandlerFactory::RC4));
     ui->algorithmComboBox->addItem(tr("AES 128-bit | R4"), int(pdf::PDFSecurityHandlerFactory::AES_128));
     ui->algorithmComboBox->addItem(tr("AES 256-bit | R6"), int(pdf::PDFSecurityHandlerFactory::AES_256));
+    ui->algorithmComboBox->addItem(tr("Certificate Encryption"), int(pdf::PDFSecurityHandlerFactory::Certificate));
 
     ui->algorithmComboBox->setCurrentIndex(0);
 
@@ -73,6 +75,7 @@ PDFEncryptionSettingsDialog::PDFEncryptionSettingsDialog(QByteArray documentId,
     m_checkBoxToPermission[ui->permAssembleCheckBox] = pdf::PDFSecurityHandler::Permission::Assemble;
     m_checkBoxToPermission[ui->permPrintHighResolutionCheckBox] = pdf::PDFSecurityHandler::Permission::PrintHighResolution;
 
+    updateCertificates();
     updateUi();
     updatePasswordScore();
 
@@ -95,6 +98,7 @@ void PDFEncryptionSettingsDialog::updateUi()
 
     const pdf::PDFSecurityHandlerFactory::Algorithm algorithm = static_cast<const pdf::PDFSecurityHandlerFactory::Algorithm>(ui->algorithmComboBox->currentData().toInt());
     const bool encrypted = algorithm != pdf::PDFSecurityHandlerFactory::None;
+    const bool isEncryptedUsingCertificate = algorithm == pdf::PDFSecurityHandlerFactory::Certificate;
 
     switch (algorithm)
     {
@@ -108,6 +112,7 @@ void PDFEncryptionSettingsDialog::updateUi()
             ui->algorithmHintWidget->setCurrentValue(4);
             break;
         case pdf::PDFSecurityHandlerFactory::AES_256:
+        case pdf::PDFSecurityHandlerFactory::Certificate:
             ui->algorithmHintWidget->setCurrentValue(5);
             break;
 
@@ -116,20 +121,40 @@ void PDFEncryptionSettingsDialog::updateUi()
             break;
     }
 
-    ui->userPasswordEnableCheckBox->setEnabled(encrypted);
-    ui->ownerPasswordEnableCheckBox->setEnabled(false);
+    ui->certificateComboBox->setEnabled(isEncryptedUsingCertificate);
 
-    if (!encrypted)
+    if (!isEncryptedUsingCertificate)
     {
-        ui->userPasswordEnableCheckBox->setChecked(false);
-        ui->ownerPasswordEnableCheckBox->setChecked(false);
+        ui->userPasswordEnableCheckBox->setEnabled(encrypted);
+        ui->ownerPasswordEnableCheckBox->setEnabled(false);
 
-        ui->userPasswordEdit->clear();
-        ui->ownerPasswordEdit->clear();
+        if (!encrypted)
+        {
+            ui->userPasswordEnableCheckBox->setChecked(false);
+            ui->ownerPasswordEnableCheckBox->setChecked(false);
+
+            ui->userPasswordEdit->clear();
+            ui->ownerPasswordEdit->clear();
+        }
+        else
+        {
+            ui->ownerPasswordEnableCheckBox->setChecked(true);
+        }
+
+        ui->certificateComboBox->setCurrentIndex(-1);
     }
     else
     {
-        ui->ownerPasswordEnableCheckBox->setChecked(true);
+        ui->userPasswordEnableCheckBox->setEnabled(false);
+        ui->ownerPasswordEnableCheckBox->setEnabled(false);
+
+        ui->userPasswordEnableCheckBox->setChecked(true);
+        ui->ownerPasswordEnableCheckBox->setChecked(false);
+
+        if (ui->certificateComboBox->currentIndex() == -1 && ui->certificateComboBox->count() > 0)
+        {
+            ui->certificateComboBox->setCurrentIndex(0);
+        }
     }
 
     ui->userPasswordEdit->setEnabled(ui->userPasswordEnableCheckBox->isChecked());
@@ -158,6 +183,21 @@ void PDFEncryptionSettingsDialog::updateUi()
     }
 }
 
+void PDFEncryptionSettingsDialog::updateCertificates()
+{
+    QFileInfoList certificates = pdf::PDFCertificateManager::getCertificates();
+
+    QVariant currentCertificate = ui->certificateComboBox->currentData();
+
+    ui->certificateComboBox->clear();
+    for (const QFileInfo& certificateItem : certificates)
+    {
+        ui->certificateComboBox->addItem(certificateItem.fileName(), certificateItem.absoluteFilePath());
+    }
+
+    ui->certificateComboBox->setCurrentIndex(ui->certificateComboBox->findData(currentCertificate));
+}
+
 void PDFEncryptionSettingsDialog::updatePasswordScore()
 {
     const pdf::PDFSecurityHandlerFactory::Algorithm algorithm = static_cast<const pdf::PDFSecurityHandlerFactory::Algorithm>(ui->algorithmComboBox->currentData().toInt());
@@ -188,6 +228,7 @@ void PDFEncryptionSettingsDialog::accept()
     settings.userPassword = ui->userPasswordEdit->text();
     settings.ownerPassword = ui->ownerPasswordEdit->text();
     settings.permissions = 0;
+    settings.certificateFileName = ui->certificateComboBox->currentData().toString();
 
     for (auto item : m_checkBoxToPermission)
     {

Pdf4QtViewer/pdfencryptionsettingsdialog.h

@@ -50,6 +50,7 @@ private:
     Ui::PDFEncryptionSettingsDialog* ui;
 
     void updateUi();
+    void updateCertificates();
     void updatePasswordScore();
 
     bool m_isUpdatingUi;

Pdf4QtViewer/pdfencryptionsettingsdialog.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>705</width>
-    <height>609</height>
+    <width>843</width>
+    <height>620</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -20,8 +20,8 @@
       <string>Encryption Method</string>
      </property>
      <layout class="QGridLayout" name="methodGroupBoxLayout">
-      <item row="0" column="1">
-       <widget class="QComboBox" name="algorithmComboBox"/>
+      <item row="0" column="2">
+       <widget class="pdfviewer::PDFEncryptionStrengthHintWidget" name="algorithmHintWidget" native="true"/>
       </item>
       <item row="0" column="0">
        <widget class="QLabel" name="encryptionAlgorithm">
@@ -30,19 +30,29 @@
         </property>
        </widget>
       </item>
-      <item row="0" column="2">
-       <widget class="pdfviewer::PDFEncryptionStrengthHintWidget" name="algorithmHintWidget" native="true"/>
+      <item row="0" column="1">
+       <widget class="QComboBox" name="algorithmComboBox"/>
       </item>
-      <item row="1" column="0" colspan="3">
+      <item row="2" column="0" colspan="3">
        <widget class="QLabel" name="encryptionMethodHintLabel">
         <property name="text">
-         <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Select encryption algorithm. AES-256 is strongly recommended, because older encryption algorithm can be potentially broken. Select older algorithms (as AES-128 or RC4) only, if you need backward compatibility. Also, choose a strong password to ensure strong encryption.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+         <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Select encryption algorithm. AES-256 is strongly recommended, because older encryption algorithm can be potentially broken. Select older algorithms (as AES-128 or RC4) only, if you need backward compatibility. Also, choose a strong password to ensure strong encryption.&lt;/p&gt;&lt;p&gt;Public key security using certificate is also supported. In that case, you must select a certificate with private key, and this certificate is then used to encrypt data. User, which wants to open document encrypted with certificate, must have a private key to the certificae.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
         </property>
         <property name="wordWrap">
          <bool>true</bool>
         </property>
        </widget>
       </item>
+      <item row="1" column="0">
+       <widget class="QLabel" name="certificateLabel">
+        <property name="text">
+         <string>Certificate</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="1">
+       <widget class="QComboBox" name="certificateComboBox"/>
+      </item>
      </layout>
     </widget>
    </item>

Pdf4QtViewer/pdfprogramcontroller.cpp

@@ -1202,6 +1202,12 @@ void PDFProgramController::onActionEncryptionTriggered()
     {
         pdf::PDFSecurityHandlerPointer updatedSecurityHandler = dialog.getUpdatedSecurityHandler();
 
+        if (!updatedSecurityHandler)
+        {
+            QMessageBox::critical(m_mainWindow, QApplication::applicationDisplayName(), tr("Failed to create security handler."));
+            return;
+        }
+
         // Jakub Melka: If we changed encryption (password), recheck, that user doesn't
         // forgot (or accidentally entered wrong) password. So, we require owner authentization
         // to continue.