Signature plugin: sign dialog + verification

Pdf4QtViewerPlugins/SignaturePlugin/SignaturePlugin.pro

@@ -43,13 +43,15 @@ SOURCES += \
     certificatemanager.cpp \
     certificatemanagerdialog.cpp \
     createcertificatedialog.cpp \
-    signatureplugin.cpp
+    signatureplugin.cpp \
+    signdialog.cpp
 	
 HEADERS += \
     certificatemanager.h \
     certificatemanagerdialog.h \
     createcertificatedialog.h \
-    signatureplugin.h
+    signatureplugin.h \
+    signdialog.h
 
 CONFIG += force_debug_info
 
@@ -61,5 +63,6 @@ RESOURCES += \
 
 FORMS += \
     certificatemanagerdialog.ui \
-    createcertificatedialog.ui
+    createcertificatedialog.ui \
+    signdialog.ui
 

Pdf4QtViewerPlugins/SignaturePlugin/certificatemanager.cpp

@@ -132,6 +132,12 @@ void CertificateManager::createCertificate(const NewCertificateInfo& info)
     }
 }
 
+QFileInfoList CertificateManager::getCertificates()
+{
+    QDir directory(getCertificateDirectory());
+    return directory.entryInfoList(QStringList() << "*.pfx", QDir::Files | QDir::NoDotAndDotDot | QDir::Readable, QDir::Name);
+}
+
 QString CertificateManager::getCertificateDirectory()
 {
     QDir directory(QStandardPaths::standardLocations(QStandardPaths::AppDataLocation).front() + "/certificates/");
@@ -156,4 +162,32 @@ QString CertificateManager::generateCertificateFileName()
     return QString();
 }
 
+bool CertificateManager::isCertificateValid(QString fileName, QString password)
+{
+    QFile file(fileName);
+    if (file.open(QFile::ReadOnly))
+    {
+        QByteArray data = file.readAll();
+        file.close();
+
+        openssl_ptr<BIO> pksBuffer(BIO_new(BIO_s_mem()), &BIO_free_all);
+        BIO_write(pksBuffer.get(), data.constData(), data.length());
+
+        openssl_ptr<PKCS12> pkcs12(d2i_PKCS12_bio(pksBuffer.get(), nullptr), &PKCS12_free);
+        if (pkcs12)
+        {
+            const char* passwordPointer = nullptr;
+            QByteArray passwordByteArray = password.isEmpty() ? QByteArray() : password.toUtf8();
+            if (!passwordByteArray.isEmpty())
+            {
+                passwordPointer = passwordByteArray.constData();
+            }
+
+            return PKCS12_parse(pkcs12.get(), passwordPointer, nullptr, nullptr, nullptr) == 1;
+        }
+    }
+
+    return false;
+}
+
 }   // namespace pdfplugin

Pdf4QtViewerPlugins/SignaturePlugin/certificatemanager.h

@@ -19,6 +19,7 @@
 #define CERTIFICATEMANAGER_H
 
 #include <QString>
+#include <QFileInfoList>
 
 namespace pdfplugin
 {
@@ -46,8 +47,10 @@ public:
 
     void createCertificate(const NewCertificateInfo& info);
 
+    static QFileInfoList getCertificates();
     static QString getCertificateDirectory();
     static QString generateCertificateFileName();
+    static bool isCertificateValid(QString fileName, QString password);
 };
 
 } // namespace pdfplugin

Pdf4QtViewerPlugins/SignaturePlugin/signatureplugin.cpp

@@ -22,6 +22,7 @@
 #include "pdfpagecontenteditorstylesettings.h"
 #include "pdfdocumentbuilder.h"
 #include "certificatemanagerdialog.h"
+#include "signdialog.h"
 
 #include <QAction>
 #include <QToolButton>
@@ -156,6 +157,7 @@ void SignaturePlugin::setWidget(pdf::PDFWidget* widget)
     connect(clearAction, &QAction::triggered, &m_scene, &pdf::PDFPageContentScene::clear);
     connect(activateAction, &QAction::triggered, this, &SignaturePlugin::setActive);
     connect(signElectronicallyAction, &QAction::triggered, this, &SignaturePlugin::onSignElectronically);
+    connect(signDigitallyAction, &QAction::triggered, this, &SignaturePlugin::onSignDigitally);
     connect(certificatesAction, &QAction::triggered, this, &SignaturePlugin::onOpenCertificatesManager);
 
     updateActions();
@@ -305,6 +307,28 @@ void SignaturePlugin::onSignElectronically()
     }
 }
 
+void SignaturePlugin::onSignDigitally()
+{
+    // Jakub Melka: do we have certificates? If not,
+    // open certificate dialog, so the user can create
+    // a new one.
+    if (CertificateManager::getCertificates().isEmpty())
+    {
+        onOpenCertificatesManager();
+
+        if (CertificateManager::getCertificates().isEmpty())
+        {
+            return;
+        }
+    }
+
+    SignDialog dialog(m_dataExchangeInterface->getMainWindow(), m_scene.isEmpty());
+    if (dialog.exec() == SignDialog::Accepted)
+    {
+
+    }
+}
+
 void SignaturePlugin::onOpenCertificatesManager()
 {
     CertificateManagerDialog dialog(m_dataExchangeInterface->getMainWindow());
@@ -422,7 +446,7 @@ void SignaturePlugin::updateActions()
     QAction* signElectronicallyAction = m_actions[SignElectronically];
     signElectronicallyAction->setEnabled(isSceneNonempty);
     QAction* signDigitallyAction = m_actions[SignDigitally];
-    signDigitallyAction->setEnabled(isSceneNonempty);
+    signDigitallyAction->setEnabled(m_document);
 }
 
 void SignaturePlugin::updateGraphics()

Pdf4QtViewerPlugins/SignaturePlugin/signatureplugin.h

@@ -54,6 +54,7 @@ private:
     void onToolActivityChanged();
     void onSceneEditElement(const std::set<pdf::PDFInteger>& elements);
     void onSignElectronically();
+    void onSignDigitally();
     void onOpenCertificatesManager();
 
     void onPenChanged(const QPen& pen);

Pdf4QtViewerPlugins/SignaturePlugin/signdialog.cpp

@@ -0,0 +1,90 @@
+//    Copyright (C) 2022 Jakub Melka
+//
+//    This file is part of PDF4QT.
+//
+//    PDF4QT is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Lesser General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    with the written consent of the copyright owner, any later version.
+//
+//    PDF4QT is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Lesser General Public License for more details.
+//
+//    You should have received a copy of the GNU Lesser General Public License
+//    along with PDF4QT.  If not, see <https://www.gnu.org/licenses/>.
+
+#include "signdialog.h"
+#include "ui_signdialog.h"
+
+#include "certificatemanager.h"
+
+#include <openssl/pkcs7.h>
+
+#include <QMessageBox>
+
+namespace pdfplugin
+{
+
+SignDialog::SignDialog(QWidget* parent, bool isSceneEmpty) :
+    QDialog(parent),
+    ui(new Ui::SignDialog)
+{
+    ui->setupUi(this);
+
+    if (!isSceneEmpty)
+    {
+        ui->methodCombo->addItem(tr("Sign digitally"), SignDigitally);
+    }
+
+    ui->methodCombo->addItem(tr("Sign digitally (invisible signature)"), SignDigitallyInvisible);
+    ui->methodCombo->setCurrentIndex(0);
+
+    QFileInfoList certificates = CertificateManager::getCertificates();
+    for (const QFileInfo& certificateFileInfo : certificates)
+    {
+        ui->certificateCombo->addItem(certificateFileInfo.fileName(), certificateFileInfo.absoluteFilePath());
+    }
+}
+
+SignDialog::~SignDialog()
+{
+    delete ui;
+}
+
+SignDialog::SignMethod SignDialog::getSignMethod() const
+{
+    return static_cast<SignMethod>(ui->methodCombo->currentData().toInt());
+}
+
+QString SignDialog::getCertificatePath() const
+{
+    return ui->certificateCombo->currentData().toString();
+}
+
+void SignDialog::accept()
+{
+    // Check certificate
+    if (!QFile::exists(getCertificatePath()))
+    {
+        QMessageBox::critical(this, tr("Error"), tr("Certificate does not exist."));
+        ui->certificateCombo->setFocus();
+        return;
+    }
+
+    // Check we can access the certificate
+    if (!CertificateManager::isCertificateValid(getCertificatePath(), ui->certificatePasswordEdit->text()))
+    {
+        QMessageBox::critical(this, tr("Error"), tr("Password to open certificate is invalid."));
+        ui->certificatePasswordEdit->setFocus();
+        return;
+    }
+
+    QDialog::accept();
+}
+
+}   // namespace pdfplugin
+
+
+

Pdf4QtViewerPlugins/SignaturePlugin/signdialog.h

@@ -0,0 +1,56 @@
+//    Copyright (C) 2022 Jakub Melka
+//
+//    This file is part of PDF4QT.
+//
+//    PDF4QT is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Lesser General Public License as published by
+//    the Free Software Foundation, either version 3 of the License, or
+//    with the written consent of the copyright owner, any later version.
+//
+//    PDF4QT is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Lesser General Public License for more details.
+//
+//    You should have received a copy of the GNU Lesser General Public License
+//    along with PDF4QT.  If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef SIGNDIALOG_H
+#define SIGNDIALOG_H
+
+#include <QDialog>
+
+namespace Ui
+{
+class SignDialog;
+}
+
+namespace pdfplugin
+{
+
+class SignDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit SignDialog(QWidget* parent, bool isSceneEmpty);
+    virtual ~SignDialog() override;
+
+    virtual void accept() override;
+
+    enum SignMethod
+    {
+        SignDigitally,
+        SignDigitallyInvisible
+    };
+
+    SignMethod getSignMethod() const;
+    QString getCertificatePath() const;
+
+private:
+    Ui::SignDialog* ui;
+};
+
+}   // namespace pdfplugin
+
+#endif // SIGNDIALOG_H

Pdf4QtViewerPlugins/SignaturePlugin/signdialog.ui

@@ -0,0 +1,160 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>SignDialog</class>
+ <widget class="QDialog" name="SignDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>501</width>
+    <height>332</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Dialog</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QGroupBox" name="selectCertificateGroupBox">
+     <property name="title">
+      <string>Sign Method</string>
+     </property>
+     <layout class="QGridLayout" name="gridLayout">
+      <item row="0" column="0">
+       <widget class="QLabel" name="methodLabel">
+        <property name="text">
+         <string>Method</string>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="1">
+       <widget class="QComboBox" name="methodCombo"/>
+      </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="certificateCombo"/>
+      </item>
+      <item row="2" column="0">
+       <widget class="QLabel" name="passwordLabel">
+        <property name="text">
+         <string>Password</string>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="1">
+       <widget class="QLineEdit" name="certificatePasswordEdit">
+        <property name="echoMode">
+         <enum>QLineEdit::Password</enum>
+        </property>
+        <property name="clearButtonEnabled">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <widget class="QGroupBox" name="parametersGroupBox">
+     <property name="title">
+      <string>Parameters</string>
+     </property>
+     <layout class="QGridLayout" name="gridLayout_2">
+      <item row="0" column="0">
+       <widget class="QLabel" name="reasonLabel">
+        <property name="text">
+         <string>Reason</string>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="1">
+       <widget class="QLineEdit" name="reasonEdit">
+        <property name="clearButtonEnabled">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="0">
+       <widget class="QLabel" name="contactInfoLabel">
+        <property name="text">
+         <string>Contact Info</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="1">
+       <widget class="QLineEdit" name="contactInfoEdit">
+        <property name="clearButtonEnabled">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
+    <spacer name="verticalSpacer">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>20</width>
+       <height>40</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>SignDialog</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>SignDialog</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>