pdf: Fix embedded files when the PDF is encrypted

When we encrypt the PDF and want to attach the ODF document to the
PDF, the PDF file would not have any attachments when opened. This
is because the encryption for the attachments and embedded files
was not done correctly. This patch fixes this issue.

Change-Id: I5bd8175f6067b8b684defa3b60746176f4314c8c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/178447
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/178771
Tested-by: Tomaž Vajngerl <quikee@gmail.com>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

2 files changed, 30 insertions, 27 deletions

diff --git a/vcl/inc/pdf/COSWriter.hxx b/vcl/inc/pdf/COSWriter.hxx
index 2142de1f846e..d63a2198a2e7 100644
--- a/vcl/inc/pdf/COSWriter.hxx
+++ b/vcl/inc/pdf/COSWriter.hxx
@@ -72,6 +72,11 @@ public:
     OStringBuffer& getLine() { return mrBuffer; }
 
     void startDict() { mrBuffer.append("<<"); }
+    void startDictWithKey(std::string_view key)
+    {
+        mrBuffer.append(key);
+        mrBuffer.append("<<");
+    }
     void endDict() { mrBuffer.append(">>\n"); }
 
     void startStream() { mrBuffer.append("stream\n"); }
diff --git a/vcl/source/gdi/pdfwriter_impl.cxx b/vcl/source/gdi/pdfwriter_impl.cxx
index faf795fa60c7..cee972efb2fe 100644
--- a/vcl/source/gdi/pdfwriter_impl.cxx
+++ b/vcl/source/gdi/pdfwriter_impl.cxx
@@ -5233,26 +5233,28 @@ bool PDFWriterImpl::emitEmbeddedFiles()
         aLine.append(" /Params ");
         appendObjectReference(nParamsObject, aLine);
         aLine.append(">>\nstream\n");
-        checkAndEnableStreamEncryption(rEmbeddedFile.m_nObject);
         if (!writeBuffer(aLine)) return false;
-        disableStreamEncryption();
         aLine.setLength(0);
 
         sal_Int64 nSize{};
         if (!rEmbeddedFile.m_aDataContainer.isEmpty())
         {
             nSize = rEmbeddedFile.m_aDataContainer.getSize();
+            checkAndEnableStreamEncryption(rEmbeddedFile.m_nObject);
             if (!writeBufferBytes(rEmbeddedFile.m_aDataContainer.getData(), rEmbeddedFile.m_aDataContainer.getSize()))
                 return false;
+            disableStreamEncryption();
         }
         else if (rEmbeddedFile.m_pStream)
         {
+            checkAndEnableStreamEncryption(rEmbeddedFile.m_nObject);
             sal_uInt64 nBegin = getCurrentFilePosition();
             css::uno::Reference<css::io::XOutputStream> xStream(new PDFStreamIf(this));
             rEmbeddedFile.m_pStream->write(xStream);
             rEmbeddedFile.m_pStream.reset();
             xStream.clear();
             nSize = sal_Int64(getCurrentFilePosition() - nBegin);
+            disableStreamEncryption();
         }
         aLine.append("\nendstream\nendobj\n\n");
         if (!writeBuffer(aLine)) return false;
@@ -5361,29 +5363,26 @@ bool PDFWriterImpl::emitCatalog()
     {
         if (!updateObject(rAttachedFile.mnObjectId))
             return false;
-        aLine.setLength( 0 );
+        aLine.setLength(0);
 
-        appendObjectID(rAttachedFile.mnObjectId, aLine);
-        aLine.append("<</Type /Filespec");
-        aLine.append("/F<");
-        COSWriter::appendUnicodeTextString(rAttachedFile.maFilename, aLine);
-        aLine.append("> ");
+        aWriter.startObject(rAttachedFile.mnObjectId);
+        aWriter.startDict();
+        aWriter.write("/Type", "/Filespec");
+        aWriter.writeKeyAndUnicodeEncrypt("/F", rAttachedFile.maFilename, rAttachedFile.mnObjectId);
         if (PDFWriter::PDFVersion::PDF_1_7 <= m_aContext.Version)
         {
-            aLine.append("/UF<");
-            COSWriter::appendUnicodeTextString(rAttachedFile.maFilename, aLine);
-            aLine.append("> ");
+            aWriter.writeKeyAndUnicodeEncrypt("/UF", rAttachedFile.maFilename, rAttachedFile.mnObjectId);
         }
         if (!rAttachedFile.maDescription.isEmpty())
         {
-            aLine.append("/Desc <");
-            COSWriter::appendUnicodeTextString(rAttachedFile.maDescription, aLine);
-            aLine.append("> ");
+            aWriter.writeKeyAndUnicodeEncrypt("/Desc", rAttachedFile.maDescription, rAttachedFile.mnObjectId);
         }
-        aLine.append("/EF <</F ");
-        appendObjectReference(rAttachedFile.mnEmbeddedFileObjectId, aLine);
-        aLine.append(">>");
-        aLine.append(">>\nendobj\n\n");
+        aLine.append("/EF");
+        aWriter.startDict();
+        aWriter.writeKeyAndReference("/F", rAttachedFile.mnEmbeddedFileObjectId);
+        aWriter.endDict();
+        aWriter.endDict();
+        aWriter.endObject();
         if (!writeBuffer(aLine)) return false;
     }
 
@@ -5408,18 +5407,17 @@ bool PDFWriterImpl::emitCatalog()
 
     if (!m_aDocumentAttachedFiles.empty())
     {
-        aLine.append("/Names ");
-        aLine.append("<</EmbeddedFiles <</Names [");
+        aWriter.startDictWithKey("/Names");
+        aWriter.startDictWithKey("/EmbeddedFiles");
+        aLine.append("/Names [");
         for (auto & rAttachedFile : m_aDocumentAttachedFiles)
         {
-            aLine.append('<');
-            COSWriter::appendUnicodeTextString(rAttachedFile.maFilename, aLine);
-            aLine.append('>');
-            aLine.append(' ');
-            appendObjectReference(rAttachedFile.mnObjectId, aLine);
+            aWriter.writeUnicodeEncrypt(rAttachedFile.maFilename, m_nCatalogObject);
+            aWriter.writeReference(rAttachedFile.mnObjectId);
         }
-        aLine.append("]>>>>");
-        aLine.append("\n" );
+        aLine.append("]");
+        aWriter.endDict();
+        aWriter.endDict();
     }
 
     if( m_aContext.PageLayout != PDFWriter::DefaultLayout )