Add tests for encryption on stamping, encryption of docs with xrefstream

Author: yulian-gaponenko

kernel/src/main/java/com/itextpdf/kernel/pdf/EncryptionConstants.java

@@ -79,7 +79,9 @@ public class EncryptionConstants implements Serializable {
     /**
      * Add this to the mode to keep encrypt only the embedded files.
      */
-    public static final int EMBEDDED_FILES_ONLY = 24;    /**
+    public static final int EMBEDDED_FILES_ONLY = 24;
+
+    /**
      * The operation permitted when the document is opened with the user password.
      */
     public static final int ALLOW_PRINTING = 4 + 2048;

kernel/src/test/java/com/itextpdf/kernel/pdf/PdfEncryptionTest.java

@@ -60,7 +60,6 @@ This file is part of the iText (R) project.
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.junit.Assert;
 import org.junit.BeforeClass;
-import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
@@ -412,14 +411,69 @@ public void encryptWithPasswordAes128EmbeddedFilesOnly() throws IOException, Gen
     public void encryptAes256Pdf2NotEncryptMetadata() throws InterruptedException, IOException, XMPException {
         String filename = "encryptAes256Pdf2NotEncryptMetadata.pdf";
         int encryptionType = EncryptionConstants.ENCRYPTION_AES_256 | EncryptionConstants.DO_NOT_ENCRYPT_METADATA;
-        encryptWithPassword(filename, encryptionType, CompressionConstants.DEFAULT_COMPRESSION);
+        encryptWithPassword(filename, encryptionType, CompressionConstants.DEFAULT_COMPRESSION, true);
+    }
+
+    @Test
+    public void encryptAes256EncryptedStampingPreserve() throws InterruptedException, IOException, XMPException {
+        String filename = "encryptAes256EncryptedStampingPreserve.pdf";
+        String src = sourceFolder + "encryptedWithPlainMetadata.pdf";
+        String out = destinationFolder + filename;
+
+        PdfDocument pdfDoc = new PdfDocument(
+                new PdfReader(src, new ReaderProperties().setPassword(OWNER)),
+                new PdfWriter(out, new WriterProperties()),
+                new StampingProperties().preserveEncryption());
+
+        pdfDoc.close();
+
+        CompareTool compareTool = new CompareTool().enableEncryptionCompare();
+        String compareResult = compareTool.compareByContent(out, sourceFolder + "cmp_" + filename, destinationFolder, "diff_", USER, USER);
+        if (compareResult != null) {
+            Assert.fail(compareResult);
+        }
+    }
+
+    @Test
+    public void encryptAes256EncryptedStampingUpdate() throws InterruptedException, IOException, XMPException {
+        String filename = "encryptAes256EncryptedStampingUpdate.pdf";
+        String src = sourceFolder + "encryptedWithPlainMetadata.pdf";
+        String out = destinationFolder + filename;
+
+        PdfDocument pdfDoc = new PdfDocument(
+                new PdfReader(src, new ReaderProperties().setPassword(OWNER)),
+                new PdfWriter(out, new WriterProperties()
+                        .setStandardEncryption(USER, OWNER, EncryptionConstants.ALLOW_PRINTING, EncryptionConstants.STANDARD_ENCRYPTION_40)),
+                new StampingProperties());
+
+        pdfDoc.close();
+
+        CompareTool compareTool = new CompareTool().enableEncryptionCompare();
+        String compareResult = compareTool.compareByContent(out, sourceFolder + "cmp_" + filename, destinationFolder, "diff_", USER, USER);
+        if (compareResult != null) {
+            Assert.fail(compareResult);
+        }
+    }
+
+    @Test
+    public void encryptAes256FullCompression() throws InterruptedException, IOException, XMPException {
+        String filename = "encryptAes256FullCompression.pdf";
+        int encryptionType = EncryptionConstants.ENCRYPTION_AES_256;
+        encryptWithPassword(filename, encryptionType, CompressionConstants.DEFAULT_COMPRESSION, true);
     }
 
     public void encryptWithPassword(String filename, int encryptionType, int compression) throws XMPException, IOException, InterruptedException {
+        encryptWithPassword(filename, encryptionType, compression, false);
+    }
+
+    public void encryptWithPassword(String filename, int encryptionType, int compression, boolean fullCompression) throws XMPException, IOException, InterruptedException {
         String outFileName = destinationFolder + filename;
         int permissions = EncryptionConstants.ALLOW_SCREENREADERS;
         PdfWriter writer = new PdfWriter(outFileName,
-                new WriterProperties().setStandardEncryption(USER, OWNER, permissions, encryptionType).addXmpMetadata());
+                new WriterProperties()
+                        .setStandardEncryption(USER, OWNER, permissions, encryptionType)
+                        .addXmpMetadata()
+                        .setFullCompressionMode(fullCompression));
         writer.setCompressionLevel(compression);
         PdfDocument document = new PdfDocument(writer);
         document.getDocumentInfo().setAuthor(author).