PDF: Allow signing documents that need password to open them

We need the password since in the middle of the signing process we need to reopen
the document we just created to do some final modifications

core/document.cpp

@@ -5516,6 +5516,7 @@ struct Okular::NewSignatureDataPrivate {
     QString certNickname;
     QString certSubjectCommonName;
     QString password;
+    QString documentPassword;
     int page;
     NormalizedRect boundingRectangle;
 };
@@ -5580,6 +5581,16 @@ void NewSignatureData::setBoundingRectangle(const NormalizedRect &rect)
     d->boundingRectangle = rect;
 }
 
+QString NewSignatureData::documentPassword() const
+{
+    return d->documentPassword;
+}
+
+void NewSignatureData::setDocumentPassword(const QString &password)
+{
+    d->documentPassword = password;
+}
+
 #undef foreachObserver
 #undef foreachObserverD
 

core/document.h

@@ -1520,6 +1520,12 @@ public:
     NormalizedRect boundingRectangle() const;
     void setBoundingRectangle(const NormalizedRect &rect);
 
+    /// @since 22.04
+    QString documentPassword() const;
+
+    /// @since 22.04
+    void setDocumentPassword(const QString &password);
+
 private:
     NewSignatureDataPrivate *const d;
 };

generators/poppler/CMakeLists.txt

@@ -55,6 +55,16 @@ int main()
 }
 " HAVE_POPPLER_21_10)
 
+check_cxx_source_compiles("
+#include <poppler-qt5.h>
+#include <poppler-form.h>
+int main()
+{
+    Poppler::PDFConverter::NewSignatureData pData;
+    pData.setDocumentOwnerPassword(QByteArray());
+}
+" HAVE_POPPLER_22_02)
+
 configure_file(
    ${CMAKE_CURRENT_SOURCE_DIR}/config-okular-poppler.h.cmake
    ${CMAKE_CURRENT_BINARY_DIR}/config-okular-poppler.h

generators/poppler/config-okular-poppler.h.cmake

@@ -13,3 +13,5 @@
 /* Defined if we have the 21.10 version of the Poppler library or later */
 #cmakedefine HAVE_POPPLER_21_10 1
 
+/* Defined if we have the 22.02 version of the Poppler library or later */
+#cmakedefine HAVE_POPPLER_22_02 1

generators/poppler/generator_pdf.cpp

@@ -1469,6 +1469,14 @@ QVariant PDFGenerator::metaData(const QString &key, const QVariant &option) cons
         return QStringLiteral("no");
 #else
         return QStringLiteral("yes");
+#endif
+    } else if (key == QLatin1String("DocumentHasPassword")) {
+        return pdfdoc->isEncrypted() ? QStringLiteral("yes") : QStringLiteral("no");
+    } else if (key == QLatin1String("CanSignDocumentWithPassword")) {
+#ifdef HAVE_POPPLER_22_02
+        return QStringLiteral("yes");
+#else
+        return QStringLiteral("no");
 #endif
     }
     return QVariant();
@@ -1920,6 +1928,10 @@ bool PDFGenerator::sign(const Okular::NewSignatureData &oData, const QString &rF
     pData.setBoundingRectangle({bRect.left, bRect.top, bRect.width(), bRect.height()});
     pData.setFontColor(Qt::black);
     pData.setBorderColor(Qt::black);
+#if HAVE_POPPLER_22_02
+    pData.setDocumentOwnerPassword(oData.documentPassword().toLatin1());
+    pData.setDocumentUserPassword(oData.documentPassword().toLatin1());
+#endif
     if (!converter->sign(pData))
         return false;
 

part/pageview.cpp

@@ -4901,6 +4901,17 @@ void PageView::slotSignature()
         return;
     }
 
+    const bool documentHasPassword = d->document->metaData(QStringLiteral("DocumentHasPassword")).toString() == QLatin1String("yes");
+    if (documentHasPassword) {
+        if (d->document->metaData(QStringLiteral("CanSignDocumentWithPassword")).toString() == QLatin1String("no")) {
+            KMessageBox::information(nullptr,
+                                     i18nc("@info", "The version of the Poppler library this Okular was compiled with does not support signing documents with passwords. Please ask your provider to update it to 22.02 or later."),
+                                     i18nc("@title:window", "Poppler library is too old"),
+                                     QStringLiteral("popplerOldSignVersion"));
+            return;
+        }
+    }
+
     const Okular::CertificateStore *certStore = d->document->certificateStore();
     bool userCancelled, nonDateValidCerts;
     const QList<Okular::CertificateInfo *> &certs = certStore->signingCertificatesForNow(&userCancelled, &nonDateValidCerts);

part/pageviewannotator.cpp

@@ -409,6 +409,15 @@ public:
             m_aborted = true;
         }
 
+        if (m_document->metaData(QStringLiteral("DocumentHasPassword")).toString() == QLatin1String("yes")) {
+            bool ok;
+            documentPassword = QInputDialog::getText(m_pageView, i18n("Enter document password"), i18n("Enter document password"), QLineEdit::Password, QString(), &ok);
+            if (!ok) {
+                passToUse.clear();
+                m_aborted = true;
+            }
+        }
+
         m_creationCompleted = false;
         clicked = false;
 
@@ -438,9 +447,11 @@ public:
         data.setCertNickname(certNicknameToUse);
         data.setCertSubjectCommonName(certCommonName);
         data.setPassword(passToUse);
+        data.setDocumentPassword(documentPassword);
         data.setPage(m_page->number());
         data.setBoundingRectangle(rect);
         passToUse.clear();
+        documentPassword.clear();
         return m_document->sign(data, newFilePath);
     }
 
@@ -448,6 +459,7 @@ private:
     QString certNicknameToUse;
     QString certCommonName;
     QString passToUse;
+    QString documentPassword;
 
     Okular::Document *m_document;
     const Okular::Page *m_page;