Validation settings, certificate store

PdfForQtViewer/pdfforqtviewer.qrc

@@ -50,5 +50,6 @@
         <file>resources/result-information.svg</file>
         <file>resources/result-ok.svg</file>
         <file>resources/result-warning.svg</file>
+        <file>resources/signature.svg</file>
     </qresource>
 </RCC>

PdfForQtViewer/pdfsidebarwidget.cpp

@@ -18,6 +18,8 @@
 #include "pdfsidebarwidget.h"
 #include "ui_pdfsidebarwidget.h"
 
+#include "pdfviewersettings.h"
+
 #include "pdfwidgetutils.h"
 #include "pdftexttospeech.h"
 
@@ -45,11 +47,17 @@ constexpr const char* STYLESHEET =
         "QWidget#speechPage { background-color: #F0F0F0 }"
         "QWidget#PDFSidebarWidget { background-color: #404040; background: green;}";
 
-PDFSidebarWidget::PDFSidebarWidget(pdf::PDFDrawWidgetProxy* proxy, PDFTextToSpeech* textToSpeech, QWidget* parent) :
+PDFSidebarWidget::PDFSidebarWidget(pdf::PDFDrawWidgetProxy* proxy,
+                                   PDFTextToSpeech* textToSpeech,
+                                   pdf::PDFCertificateStore* certificateStore,
+                                   PDFViewerSettings* settings,
+                                   QWidget* parent) :
     QWidget(parent),
     ui(new Ui::PDFSidebarWidget),
     m_proxy(proxy),
     m_textToSpeech(textToSpeech),
+    m_certificateStore(certificateStore),
+    m_settings(settings),
     m_outlineTreeModel(nullptr),
     m_thumbnailsModel(nullptr),
     m_optionalContentTreeModel(nullptr),
@@ -114,6 +122,9 @@ PDFSidebarWidget::PDFSidebarWidget(pdf::PDFDrawWidgetProxy* proxy, PDFTextToSpee
                                  ui->speechRateValueLabel, ui->speechPitchValueLabel, ui->speechVolumeValueLabel,
                                  ui->speechActualTextEdit);
 
+    ui->signatureTreeWidget->setContextMenuPolicy(Qt::CustomContextMenu);
+    connect(ui->signatureTreeWidget, &QTreeWidget::customContextMenuRequested, this, &PDFSidebarWidget::onSignatureCustomContextMenuRequested);
+
     selectPage(Invalid);
     updateButtons();
 }
@@ -342,11 +353,18 @@ void PDFSidebarWidget::updateSignatures(const std::vector<pdf::PDFSignatureVerif
     ui->signatureTreeWidget->setUpdatesEnabled(false);
     ui->signatureTreeWidget->clear();
 
+    m_certificateInfos.clear();
+
     QIcon okIcon(":/resources/result-ok.svg");
     QIcon errorIcon(":/resources/result-error.svg");
     QIcon warningIcon(":/resources/result-warning.svg");
     QIcon infoIcon(":/resources/result-information.svg");
 
+    if (m_settings->getSettings().m_signatureTreatWarningsAsErrors)
+    {
+        warningIcon = errorIcon;
+    }
+
     for (const pdf::PDFSignatureVerificationResult& signature : signatures)
     {
         const pdf::PDFCertificateInfos& certificateInfos = signature.getCertificateInfos();
@@ -401,6 +419,13 @@ void PDFSidebarWidget::updateSignatures(const std::vector<pdf::PDFSignatureVerif
                 QTreeWidgetItem* certRoot = new QTreeWidgetItem(certChainRoot, QStringList(currentCertificateInfo.getName(pdf::PDFCertificateInfo::CommonName)));
                 certRoot->setIcon(0, infoIcon);
 
+                pdf::PDFCertificateInfo::KeyUsageFlags keyUsageFlags = currentCertificateInfo.getKeyUsage();
+                if (keyUsageFlags.testFlag(pdf::PDFCertificateInfo::KeyUsageCertSign))
+                {
+                    m_certificateInfos.push_back(currentCertificateInfo);
+                    certRoot->setData(0, Qt::UserRole, m_certificateInfos.size() - 1);
+                }
+
                 auto addName = [certRoot, &currentCertificateInfo, &infoIcon](pdf::PDFCertificateInfo::NameEntry nameEntry, QString caption)
                 {
                     QString text = currentCertificateInfo.getName(nameEntry);
@@ -473,7 +498,6 @@ void PDFSidebarWidget::updateSignatures(const std::vector<pdf::PDFSignatureVerif
                 }
 
                 QStringList keyUsages;
-                pdf::PDFCertificateInfo::KeyUsageFlags keyUsageFlags = currentCertificateInfo.getKeyUsage();
                 if (keyUsageFlags.testFlag(pdf::PDFCertificateInfo::KeyUsageDigitalSignature))
                 {
                     keyUsages << tr("Digital signatures");
@@ -619,6 +643,37 @@ void PDFSidebarWidget::onThumbnailClicked(const QModelIndex& index)
     }
 }
 
+void PDFSidebarWidget::onSignatureCustomContextMenuRequested(const QPoint& pos)
+{
+    if (QTreeWidgetItem* item = ui->signatureTreeWidget->itemAt(pos))
+    {
+        QVariant data = item->data(0, Qt::UserRole);
+        if (data.isValid())
+        {
+            const pdf::PDFCertificateInfo& info = m_certificateInfos.at(data.toInt());
+            if (!m_certificateStore->contains(info))
+            {
+                QMenu menu;
+                QAction* action = menu.addAction(tr("Add to trusted certificates"));
+
+                auto addCertificate = [this, info]()
+                {
+                    if (QMessageBox::question(this, tr("Add to Trusted Certificate Store"), tr("Are you sure want to add '%1' to the trusted certificate store?").arg(info.getName(pdf::PDFCertificateInfo::CommonName))) == QMessageBox::Yes)
+                    {
+                        if (!m_certificateStore->add(pdf::PDFCertificateStore::EntryType::User, info))
+                        {
+                            QMessageBox::critical(this, tr("Trusted Certificate Store Error"), tr("Failed to add certificate to the trusted certificate store."));
+                        }
+                    }
+                };
+                connect(action, &QAction::triggered, this, addCertificate);
+
+                menu.exec(ui->signatureTreeWidget->viewport()->mapToGlobal(pos));
+            }
+        }
+    }
+}
+
 void PDFSidebarWidget::paintEvent(QPaintEvent* event)
 {
     Q_UNUSED(event);

PdfForQtViewer/pdfsidebarwidget.h

@@ -35,7 +35,9 @@ namespace pdf
 {
 class PDFAction;
 class PDFDocument;
+class PDFCertificateInfo;
 class PDFDrawWidgetProxy;
+class PDFCertificateStore;
 class PDFModifiedDocument;
 class PDFThumbnailsItemModel;
 class PDFOutlineTreeItemModel;
@@ -48,13 +50,18 @@ class PDFOptionalContentTreeItemModel;
 namespace pdfviewer
 {
 class PDFTextToSpeech;
+class PDFViewerSettings;
 
 class PDFSidebarWidget : public QWidget
 {
     Q_OBJECT
 
 public:
-    explicit PDFSidebarWidget(pdf::PDFDrawWidgetProxy* proxy, PDFTextToSpeech* textToSpeech, QWidget* parent);
+    explicit PDFSidebarWidget(pdf::PDFDrawWidgetProxy* proxy,
+                              PDFTextToSpeech* textToSpeech,
+                              pdf::PDFCertificateStore* certificateStore,
+                              PDFViewerSettings* settings,
+                              QWidget* parent);
     virtual ~PDFSidebarWidget() override;
 
     virtual void paintEvent(QPaintEvent* event) override;
@@ -102,6 +109,7 @@ private:
     void onThumbnailsSizeChanged(int size);
     void onAttachmentCustomContextMenuRequested(const QPoint& pos);
     void onThumbnailClicked(const QModelIndex& index);
+    void onSignatureCustomContextMenuRequested(const QPoint &pos);
 
     struct PageInfo
     {
@@ -112,6 +120,8 @@ private:
     Ui::PDFSidebarWidget* ui;
     pdf::PDFDrawWidgetProxy* m_proxy;
     PDFTextToSpeech* m_textToSpeech;
+    pdf::PDFCertificateStore* m_certificateStore;
+    PDFViewerSettings* m_settings;
     pdf::PDFOutlineTreeItemModel* m_outlineTreeModel;
     pdf::PDFThumbnailsItemModel* m_thumbnailsModel;
     pdf::PDFOptionalContentTreeItemModel* m_optionalContentTreeModel;
@@ -120,6 +130,7 @@ private:
     pdf::PDFAttachmentsTreeItemModel* m_attachmentsTreeModel;
     std::map<Page, PageInfo> m_pageInfo;
     std::vector<pdf::PDFSignatureVerificationResult> m_signatures;
+    std::vector<pdf::PDFCertificateInfo> m_certificateInfos;
 };
 
 }   // namespace pdfviewer

PdfForQtViewer/pdfviewermainwindow.cpp

@@ -217,7 +217,7 @@ PDFViewerMainWindow::PDFViewerMainWindow(QWidget* parent) :
     m_pdfWidget->getDrawWidgetProxy()->setProgress(m_progress);
     m_textToSpeech->setProxy(m_pdfWidget->getDrawWidgetProxy());
 
-    m_sidebarWidget = new PDFSidebarWidget(m_pdfWidget->getDrawWidgetProxy(), m_textToSpeech, this);
+    m_sidebarWidget = new PDFSidebarWidget(m_pdfWidget->getDrawWidgetProxy(), m_textToSpeech, &m_certificateStore, m_settings, this);
     m_sidebarDockWidget = new QDockWidget(tr("Sidebar"), this);
     m_sidebarDockWidget->setObjectName("SidebarDockWidget");
     m_sidebarDockWidget->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
@@ -966,8 +966,14 @@ void PDFViewerMainWindow::openDocument(const QString& fileName)
         if (result.result == pdf::PDFDocumentReader::Result::OK)
         {
             // Verify signatures
+            pdf::PDFSignatureHandler::Parameters parameters;
+            parameters.store = &m_certificateStore;
+            parameters.enableVerification = m_settings->getSettings().m_signatureVerificationEnabled;
+            parameters.ignoreExpirationDate = m_settings->getSettings().m_signatureIgnoreCertificateValidityTime;
+            parameters.useSystemCertificateStore = m_settings->getSettings().m_signatureUseSystemStore;
+
             pdf::PDFForm form = pdf::PDFForm::parse(&document, document.getCatalog()->getFormObject());
-            result.signatures = pdf::PDFSignatureHandler::verifySignatures(form, reader.getSource());
+            result.signatures = pdf::PDFSignatureHandler::verifySignatures(form, reader.getSource(), parameters);
             result.document.reset(new pdf::PDFDocument(qMove(document)));
         }
 

PdfForQtViewer/pdfviewermainwindow.h

@@ -98,11 +98,8 @@ private slots:
     void on_actionRotateLeft_triggered();
     void on_actionPrint_triggered();
     void on_actionRender_to_Images_triggered();
-
     void on_actionOptimize_triggered();
-
     void on_actionSave_As_triggered();
-
     void on_actionSave_triggered();
 
 private:
@@ -180,6 +177,7 @@ private:
     QWinTaskbarButton* m_taskbarButton;
     QWinTaskbarProgress* m_progressTaskbarIndicator;
     PDFFileInfo m_fileInfo;
+    pdf::PDFCertificateStore m_certificateStore;
     std::vector<pdf::PDFSignatureVerificationResult> m_signatures;
 
     QFuture<AsyncReadingResult> m_future;

PdfForQtViewer/pdfviewersettings.cpp

@@ -86,6 +86,13 @@ void PDFViewerSettings::readSettings(QSettings& settings, const pdf::PDFCMSSetti
     m_settings.m_formAppearanceFlags = static_cast<pdf::PDFFormManager::FormAppearanceFlags>(settings.value("formAppearance", int(pdf::PDFFormManager::getDefaultApperanceFlags())).toInt());
     settings.endGroup();
 
+    settings.beginGroup("Signature");
+    m_settings.m_signatureVerificationEnabled = settings.value("signatureVerificationEnabled", defaultSettings.m_signatureVerificationEnabled).toBool();
+    m_settings.m_signatureTreatWarningsAsErrors = settings.value("signatureTreatWarningsAsErrors", defaultSettings.m_signatureTreatWarningsAsErrors).toBool();
+    m_settings.m_signatureIgnoreCertificateValidityTime = settings.value("signatureIgnoreCertificateValidityTime", defaultSettings.m_signatureIgnoreCertificateValidityTime).toBool();
+    m_settings.m_signatureUseSystemStore = settings.value("signatureUseSystemStore", defaultSettings.m_signatureUseSystemStore).toBool();
+    settings.endGroup();
+
     emit settingsChanged();
 }
 
@@ -139,6 +146,13 @@ void PDFViewerSettings::writeSettings(QSettings& settings)
     settings.beginGroup("Forms");
     settings.setValue("formAppearance", int(m_settings.m_formAppearanceFlags));
     settings.endGroup();
+
+    settings.beginGroup("Signature");
+    settings.setValue("signatureVerificationEnabled", m_settings.m_signatureVerificationEnabled);
+    settings.setValue("signatureTreatWarningsAsErrors", m_settings.m_signatureTreatWarningsAsErrors);
+    settings.setValue("signatureIgnoreCertificateValidityTime", m_settings.m_signatureIgnoreCertificateValidityTime);
+    settings.setValue("signatureUseSystemStore", m_settings.m_signatureUseSystemStore);
+    settings.endGroup();
 }
 
 QString PDFViewerSettings::getDirectory() const
@@ -247,7 +261,11 @@ PDFViewerSettings::Settings::Settings() :
     m_magnifierZoom(2.0),
     m_maximumUndoSteps(5),
     m_maximumRedoSteps(5),
-    m_formAppearanceFlags(pdf::PDFFormManager::getDefaultApperanceFlags())
+    m_formAppearanceFlags(pdf::PDFFormManager::getDefaultApperanceFlags()),
+    m_signatureVerificationEnabled(true),
+    m_signatureTreatWarningsAsErrors(false),
+    m_signatureIgnoreCertificateValidityTime(false),
+    m_signatureUseSystemStore(true)
 {
 
 }

PdfForQtViewer/pdfviewersettings.h

@@ -83,6 +83,12 @@ public:
 
         // Form settings
         pdf::PDFFormManager::FormAppearanceFlags m_formAppearanceFlags;
+
+        // Signature settings
+        bool m_signatureVerificationEnabled;
+        bool m_signatureTreatWarningsAsErrors;
+        bool m_signatureIgnoreCertificateValidityTime;
+        bool m_signatureUseSystemStore;
     };
 
     const Settings& getSettings() const { return m_settings; }

PdfForQtViewer/pdfviewersettingsdialog.cpp

@@ -59,6 +59,7 @@ PDFViewerSettingsDialog::PDFViewerSettingsDialog(const PDFViewerSettings::Settin
     new QListWidgetItem(QIcon(":/resources/ui.svg"), tr("UI"), ui->optionsPagesWidget, UISettings);
     new QListWidgetItem(QIcon(":/resources/speech.svg"), tr("Speech"), ui->optionsPagesWidget, SpeechSettings);
     new QListWidgetItem(QIcon(":/resources/form-settings.svg"), tr("Forms"), ui->optionsPagesWidget, FormSettings);
+    new QListWidgetItem(QIcon(":/resources/signature.svg"), tr("Signature"), ui->optionsPagesWidget, SignatureSettings);
 
     ui->renderingEngineComboBox->addItem(tr("Software"), static_cast<int>(pdf::RendererEngine::Software));
     ui->renderingEngineComboBox->addItem(tr("Hardware accelerated (OpenGL)"), static_cast<int>(pdf::RendererEngine::OpenGL));
@@ -198,6 +199,10 @@ void PDFViewerSettingsDialog::on_optionsPagesWidget_currentItemChanged(QListWidg
             ui->stackedWidget->setCurrentWidget(ui->formPage);
             break;
 
+        case SignatureSettings:
+            ui->stackedWidget->setCurrentWidget(ui->signaturePage);
+            break;
+
         default:
             Q_ASSERT(false);
             break;
@@ -327,6 +332,12 @@ void PDFViewerSettingsDialog::loadData()
     // Form Settings
     ui->formHighlightFieldsCheckBox->setChecked(m_settings.m_formAppearanceFlags.testFlag(pdf::PDFFormManager::HighlightFields));
     ui->formHighlightRequiredFieldsCheckBox->setChecked(m_settings.m_formAppearanceFlags.testFlag(pdf::PDFFormManager::HighlightRequiredFields));
+
+    // Signature Settings
+    ui->signatureVerificationEnableCheckBox->setChecked(m_settings.m_signatureVerificationEnabled);
+    ui->signatureStrictModeEnabledCheckBox->setChecked(m_settings.m_signatureTreatWarningsAsErrors);
+    ui->signatureIgnoreExpiredCheckBox->setChecked(m_settings.m_signatureIgnoreCertificateValidityTime);
+    ui->signatureUseSystemCertificateStoreCheckBox->setChecked(m_settings.m_signatureUseSystemStore);
 }
 
 void PDFViewerSettingsDialog::saveData()
@@ -514,6 +525,22 @@ void PDFViewerSettingsDialog::saveData()
     {
         m_settings.m_maximumRedoSteps = ui->maximumRedoStepsEdit->value();
     }
+    else if (sender == ui->signatureVerificationEnableCheckBox)
+    {
+        m_settings.m_signatureVerificationEnabled = ui->signatureVerificationEnableCheckBox->isChecked();
+    }
+    else if (sender == ui->signatureStrictModeEnabledCheckBox)
+    {
+        m_settings.m_signatureTreatWarningsAsErrors = ui->signatureStrictModeEnabledCheckBox->isChecked();
+    }
+    else if (sender == ui->signatureIgnoreExpiredCheckBox)
+    {
+        m_settings.m_signatureIgnoreCertificateValidityTime = ui->signatureIgnoreExpiredCheckBox->isChecked();
+    }
+    else if (sender == ui->signatureUseSystemCertificateStoreCheckBox)
+    {
+        m_settings.m_signatureUseSystemStore = ui->signatureUseSystemCertificateStoreCheckBox->isChecked();
+    }
 
     const bool loadData = !qobject_cast<const QDoubleSpinBox*>(sender) && !qobject_cast<const QSpinBox*>(sender);
     if (loadData)

PdfForQtViewer/pdfviewersettingsdialog.h

@@ -71,7 +71,8 @@ public:
         SecuritySettings,
         UISettings,
         SpeechSettings,
-        FormSettings
+        FormSettings,
+        SignatureSettings
     };
 
     const PDFViewerSettings::Settings& getSettings() const { return m_settings; }

PdfForQtViewer/pdfviewersettingsdialog.ui

@@ -26,7 +26,7 @@
      <item>
       <widget class="QStackedWidget" name="stackedWidget">
        <property name="currentIndex">
-        <number>1</number>
+        <number>10</number>
        </property>
        <widget class="QWidget" name="enginePage">
         <layout class="QVBoxLayout" name="enginePageLayout">
@@ -1176,6 +1176,156 @@
          </item>
         </layout>
        </widget>
+       <widget class="QWidget" name="signaturePage">
+        <layout class="QVBoxLayout" name="signaturePageLayout">
+         <property name="leftMargin">
+          <number>0</number>
+         </property>
+         <property name="topMargin">
+          <number>0</number>
+         </property>
+         <property name="rightMargin">
+          <number>0</number>
+         </property>
+         <property name="bottomMargin">
+          <number>0</number>
+         </property>
+         <item>
+          <widget class="QGroupBox" name="signatureGroupBox">
+           <property name="title">
+            <string>Digital Signature Verification</string>
+           </property>
+           <layout class="QVBoxLayout" name="signatureGroupBoxLayout">
+            <item>
+             <layout class="QGridLayout" name="signatureWidgetsLayout">
+              <item row="2" column="0">
+               <widget class="QLabel" name="signatureIgnoreExpiredLabel">
+                <property name="text">
+                 <string>Ignore expired certificates</string>
+                </property>
+               </widget>
+              </item>
+              <item row="0" column="0">
+               <widget class="QLabel" name="signatureVerificationLabel">
+                <property name="text">
+                 <string>Signature verification</string>
+                </property>
+               </widget>
+              </item>
+              <item row="1" column="0">
+               <widget class="QLabel" name="signatureStrictModeLabel">
+                <property name="text">
+                 <string>Strict mode</string>
+                </property>
+               </widget>
+              </item>
+              <item row="0" column="1">
+               <widget class="QCheckBox" name="signatureVerificationEnableCheckBox">
+                <property name="text">
+                 <string>Enable</string>
+                </property>
+               </widget>
+              </item>
+              <item row="1" column="1">
+               <widget class="QCheckBox" name="signatureStrictModeEnabledCheckBox">
+                <property name="text">
+                 <string>Enable</string>
+                </property>
+               </widget>
+              </item>
+              <item row="3" column="0">
+               <widget class="QLabel" name="signatureUseSystemCertificateStoreLabel">
+                <property name="text">
+                 <string>Use system certificate store</string>
+                </property>
+               </widget>
+              </item>
+              <item row="2" column="1">
+               <widget class="QCheckBox" name="signatureIgnoreExpiredCheckBox">
+                <property name="text">
+                 <string>Enable</string>
+                </property>
+               </widget>
+              </item>
+              <item row="3" column="1">
+               <widget class="QCheckBox" name="signatureUseSystemCertificateStoreCheckBox">
+                <property name="text">
+                 <string>Enable</string>
+                </property>
+               </widget>
+              </item>
+             </layout>
+            </item>
+            <item>
+             <widget class="Line" name="line">
+              <property name="orientation">
+               <enum>Qt::Horizontal</enum>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QLabel" name="signatureCertificatesTableLabel">
+              <property name="text">
+               <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;&lt;span style=&quot; font-weight:600;&quot;&gt;Trusted certificate store&lt;/span&gt;&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QTableWidget" name="trustedCertificateStoreTableWidget"/>
+            </item>
+            <item>
+             <layout class="QHBoxLayout" name="trustedCertificateStoreButtonsLayout">
+              <item>
+               <spacer name="trustedCertificateStoreButtonsSpacer">
+                <property name="orientation">
+                 <enum>Qt::Horizontal</enum>
+                </property>
+                <property name="sizeHint" stdset="0">
+                 <size>
+                  <width>40</width>
+                  <height>20</height>
+                 </size>
+                </property>
+               </spacer>
+              </item>
+              <item>
+               <widget class="QPushButton" name="removeCertificateButton">
+                <property name="text">
+                 <string>Remove</string>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <widget class="QPushButton" name="trustedCertificateStoreDownloadEUTLButton">
+                <property name="text">
+                 <string>Download EUTL</string>
+                </property>
+               </widget>
+              </item>
+             </layout>
+            </item>
+            <item>
+             <widget class="Line" name="line_2">
+              <property name="orientation">
+               <enum>Qt::Horizontal</enum>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QLabel" name="signatureInfoLabel">
+              <property name="text">
+               <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Settings for verification of digital signatures. Digital signatures are verified as strict, as possible, to avoid any malicious content or signature manipulation. Verification can also be turned off, if it is not wanted. When &lt;span style=&quot; font-weight:600;&quot;&gt;Strict mode&lt;/span&gt; is turned on, every warning is treated as error. You can also ignore certificate expiration date, but do this only, if you know what you are doing, because it is dangerous. For verification, list of trusted certificates is used. System certificates can be inserted into the list, and also you can manage your own list of trusted certificates. Also, certificates from EUTL (EU trusted list) can be downloaded into the trusted certificate storage.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+              </property>
+              <property name="wordWrap">
+               <bool>true</bool>
+              </property>
+             </widget>
+            </item>
+           </layout>
+          </widget>
+         </item>
+        </layout>
+       </widget>
       </widget>
      </item>
     </layout>

PdfForQtViewer/resources/signature.svg

@@ -0,0 +1,94 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   width="30mm"
+   height="30mm"
+   viewBox="0 0 30 30"
+   version="1.1"
+   id="svg8"
+   inkscape:version="0.92.4 (5da689c313, 2019-01-14)"
+   sodipodi:docname="signature.svg">
+  <defs
+     id="defs2">
+    <inkscape:path-effect
+       effect="spiro"
+       id="path-effect831"
+       is_visible="true" />
+  </defs>
+  <sodipodi:namedview
+     id="base"
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1.0"
+     inkscape:pageopacity="0.0"
+     inkscape:pageshadow="2"
+     inkscape:zoom="5.6"
+     inkscape:cx="166.75422"
+     inkscape:cy="113.44001"
+     inkscape:document-units="mm"
+     inkscape:current-layer="layer1"
+     showgrid="false"
+     inkscape:window-width="3840"
+     inkscape:window-height="2035"
+     inkscape:window-x="-13"
+     inkscape:window-y="-13"
+     inkscape:window-maximized="1" />
+  <metadata
+     id="metadata5">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title></dc:title>
+        <cc:license
+           rdf:resource="http://creativecommons.org/licenses/by-sa/4.0/" />
+        <dc:creator>
+          <cc:Agent>
+            <dc:title>Jakub Melka</dc:title>
+          </cc:Agent>
+        </dc:creator>
+      </cc:Work>
+      <cc:License
+         rdf:about="http://creativecommons.org/licenses/by-sa/4.0/">
+        <cc:permits
+           rdf:resource="http://creativecommons.org/ns#Reproduction" />
+        <cc:permits
+           rdf:resource="http://creativecommons.org/ns#Distribution" />
+        <cc:requires
+           rdf:resource="http://creativecommons.org/ns#Notice" />
+        <cc:requires
+           rdf:resource="http://creativecommons.org/ns#Attribution" />
+        <cc:permits
+           rdf:resource="http://creativecommons.org/ns#DerivativeWorks" />
+        <cc:requires
+           rdf:resource="http://creativecommons.org/ns#ShareAlike" />
+      </cc:License>
+    </rdf:RDF>
+  </metadata>
+  <g
+     inkscape:label="Vrstva 1"
+     inkscape:groupmode="layer"
+     id="layer1"
+     transform="translate(0,-267)">
+    <g
+       aria-label="✍"
+       style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:25.39999962px;line-height:1.25;font-family:sans-serif;-inkscape-font-specification:sans-serif;letter-spacing:0px;word-spacing:0px;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.26458332"
+       id="text837">
+      <path
+         d="m 24.320405,282.11063 h 4.7625 v 12.47675 H 2.7899365 q -0.471289,0 -0.8805664,-0.17363 -0.396875,-0.17363 -0.7069336,-0.48369 -0.29765621,-0.29766 -0.47128902,-0.70693 -0.17363281,-0.39688 -0.17363281,-0.86817 0,-0.59531 0.24804687,-1.00459 0.24804686,-0.40928 0.64492186,-0.80615 v -1.15342 l 1.5875,-1.5875 q -0.3348633,-0.47129 -0.5208984,-1.00459 -0.1736329,-0.5457 -0.1736329,-1.12861 0,-0.70693 0.2604493,-1.35186 0.2728515,-0.65732 0.7813476,-1.16582 l 5.3454101,-5.34541 q 0.5084961,-0.50849 1.1534179,-0.76894 0.657324,-0.27285 1.364258,-0.27285 h 2.827734 l 6.98252,-6.98252 4.303613,4.30361 -4.526856,4.52686 z m -0.744141,1.78593 -4.638476,-4.65088 q -0.111621,0.11163 -0.496094,0.4961 -0.37207,0.38447 -0.880566,0.89297 -0.496094,0.50849 -1.066602,1.079 -0.558105,0.57051 -1.041797,1.0542 -0.483691,0.48369 -0.818554,0.81856 -0.334864,0.32246 -0.396875,0.35966 0.384472,0.13643 0.483691,0.47129 0.111621,0.32246 0.111621,0.68213 0,0.14883 -0.0124,0.29766 0,0.13642 0,0.27285 0,0.74414 -0.285254,1.40146 -0.272852,0.64493 -0.756543,1.12862 -0.483691,0.48369 -1.141016,0.76894 -0.644922,0.27285 -1.389062,0.27285 H 7.6888622 q -0.3720703,0 -0.6945312,0.13643 -0.322461,0.14883 -0.5705078,0.38447 -0.2356446,0.24805 -0.3844727,0.57051 -0.1364258,0.32246 -0.1364258,0.69453 0,0.33486 0.1364258,0.68213 0.062012,0.0992 0.1116211,0.18604 0.049609,0.0992 0.1116211,0.19843 0.2480469,0.32246 0.6325195,0.5085 0.396875,0.19844 0.79375,0.19844 H 27.296967 v -8.90489 z m -18.566308,8.01192 0.1240234,-0.11162 q -0.1240234,-0.35967 -0.1240234,-0.76895 0,-0.5581 0.2108398,-1.0418 0.2108399,-0.48369 0.5705079,-0.84335 0.3720703,-0.37208 0.8557617,-0.58292 0.4836914,-0.21083 1.0417968,-0.21083 H 8.581831 q 3.150195,-3.1254 6.238379,-6.22598 3.100586,-3.11299 6.238379,-6.25078 l -1.785938,-1.78594 q -4.005957,4.00596 -8.024316,8.01191 -4.0183595,4.00596 -8.0119141,8.03672 v 1.77354 z m 6.238379,-13.36973 q -0.731738,0 -1.2526369,0.5209 l -5.3454101,5.35781 q -0.2480468,0.24805 -0.396875,0.58291 -0.1364257,0.32246 -0.1364257,0.68213 0,0.48369 0.2232422,0.84336 0.2356445,0.35967 0.5953124,0.64492 l 8.6196291,-8.63203 z m 9.810254,-6.23838 -1.153418,1.15342 1.785937,1.78594 1.153418,-1.15342 z"
+         style="stroke-width:0.26458332"
+         id="path839"
+         inkscape:connector-curvature="0" />
+    </g>
+  </g>
+</svg>