Fix constructor of PdfReader to close() the PdfTokenizer when exception thrown

Add PdfWriter/PdfReader/PdfDocument constructors to try-with-resources
Add tests to compareLinkAnnotation method and encrypt method

DEVSIX-3504

Author: Yahor Martsynkovsky

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

@@ -43,6 +43,7 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.kernel.pdf;
 
+import java.io.IOException;
 import java.io.OutputStream;
 import java.security.PrivateKey;
 import java.util.Map;
@@ -241,12 +242,15 @@ public PdfEncryptor setEncryptionProperties(EncryptionProperties properties) {
     public void encrypt(PdfReader reader, OutputStream os, Map<String, String> newInfo) {
         WriterProperties writerProperties = new WriterProperties();
         writerProperties.encryptionProperties = properties;
-        PdfWriter writer = new PdfWriter(os, writerProperties);
         StampingProperties stampingProperties = new StampingProperties();
         stampingProperties.setEventCountingMetaInfo(metaInfo);
-        PdfDocument document = new PdfDocument(reader, writer, stampingProperties);
-        document.getDocumentInfo().setMoreInfo(newInfo);
-        document.close();
+        try (PdfWriter writer = new PdfWriter(os, writerProperties);
+                PdfDocument document = new PdfDocument(reader, writer, stampingProperties)) {
+            document.getDocumentInfo().setMoreInfo(newInfo);
+        } catch (IOException e) {
+            //The close() method of OutputStream throws an exception, but we don't need to do anything in this case,
+            // because OutputStream#close() does nothing.
+        }
     }
 
     /**

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

@@ -1312,8 +1312,19 @@ private void readDecryptObj() {
      * @throws IOException if there is a problem reading the byte source
      */
     private static PdfTokenizer getOffsetTokeniser(IRandomAccessSource byteSource) throws IOException {
+        com.itextpdf.io.IOException possibleException = null;
         PdfTokenizer tok = new PdfTokenizer(new RandomAccessFileOrArray(byteSource));
-        int offset = tok.getHeaderOffset();
+        int offset;
+        try {
+            offset = tok.getHeaderOffset();
+        } catch (com.itextpdf.io.IOException ex) {
+            possibleException = ex;
+            throw possibleException;
+        } finally {
+            if (possibleException != null) {
+                tok.close();
+            }
+        }
         if (offset != 0) {
             IRandomAccessSource offsetSource = new WindowRandomAccessSource(byteSource, offset);
             tok = new PdfTokenizer(new RandomAccessFileOrArray(offsetSource));

kernel/src/main/java/com/itextpdf/kernel/utils/CompareTool.java

@@ -0,0 +1,90 @@
+/*
+    This file is part of the iText (R) project.
+    Copyright (c) 1998-2021 iText Group NV
+    Authors: iText Software.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License version 3
+    as published by the Free Software Foundation with the addition of the
+    following permission added to Section 15 as permitted in Section 7(a):
+    FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
+    ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
+    OF THIRD PARTY RIGHTS
+
+    This program 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 Affero General Public License for more details.
+    You should have received a copy of the GNU Affero General Public License
+    along with this program; if not, see http://www.gnu.org/licenses or write to
+    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+    Boston, MA, 02110-1301 USA, or download the license from the following URL:
+    http://itextpdf.com/terms-of-use/
+
+    The interactive user interfaces in modified source and object code versions
+    of this program must display Appropriate Legal Notices, as required under
+    Section 5 of the GNU Affero General Public License.
+
+    In accordance with Section 7(b) of the GNU Affero General Public License,
+    a covered work must retain the producer line in every PDF that is created
+    or manipulated using iText.
+
+    You can be released from the requirements of the license by purchasing
+    a commercial license. Buying such a license is mandatory as soon as you
+    develop commercial activities involving the iText software without
+    disclosing the source code of your own applications.
+    These activities include: offering paid services to customers as an ASP,
+    serving PDFs on the fly in a web application, shipping iText with a closed
+    source product.
+
+    For more information, please contact iText Software Corp. at this
+    address: [email protected]
+ */
+package com.itextpdf.kernel.pdf;
+
+import com.itextpdf.test.ExtendedITextTest;
+import com.itextpdf.test.annotations.type.IntegrationTest;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.junit.rules.ExpectedException;
+
+@Category(IntegrationTest.class)
+public class PdfEncryptorTest extends ExtendedITextTest {
+
+    public static final String SOURCE_FOLDER = "./src/test/resources/com/itextpdf/kernel/pdf/PdfEncryptorTest/";
+    public static final String DESTINATION_FOLDER = "./target/test/com/itextpdf/kernel/pdf/PdfEncryptorTest/";
+
+
+    @BeforeClass
+    public static void beforeClass() {
+        createDestinationFolder(DESTINATION_FOLDER);
+    }
+
+    @Test
+    public void encryptFileTest() throws IOException {
+        String outFileName = DESTINATION_FOLDER + "encryptFileTest.pdf";
+        String initialFileName = SOURCE_FOLDER + "initial.pdf";
+        PdfEncryptor encryptor = new PdfEncryptor();
+        EncryptionProperties encryptionProperties = new EncryptionProperties();
+        encryptionProperties.setStandardEncryption(new byte[16], new byte[16], 0, 0);
+        encryptor.setEncryptionProperties(encryptionProperties);
+
+        try (PdfReader initialFile = new PdfReader(initialFileName);
+                FileOutputStream outputStream = new FileOutputStream(outFileName)) {
+            encryptor.encrypt(initialFile, outputStream);
+        }
+
+        ReaderProperties readerProperties = new ReaderProperties();
+        readerProperties.setPassword(new byte[16]);
+        PdfReader outFile = new PdfReader(outFileName, readerProperties);
+        PdfDocument doc = new PdfDocument(outFile);
+        doc.close();
+        Assert.assertTrue(outFile.isEncrypted());
+    }
+}

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

@@ -43,14 +43,26 @@ This file is part of the iText (R) project.
 package com.itextpdf.kernel.utils;
 
 import com.itextpdf.io.IoExceptionMessage;
+import com.itextpdf.io.font.constants.StandardFonts;
 import com.itextpdf.io.util.GhostscriptHelper;
 import com.itextpdf.io.util.SystemUtil;
+import com.itextpdf.kernel.font.PdfFontFactory;
+import com.itextpdf.kernel.geom.Rectangle;
+import com.itextpdf.kernel.pdf.PdfArray;
+import com.itextpdf.kernel.pdf.PdfDocument;
+import com.itextpdf.kernel.pdf.PdfPage;
+import com.itextpdf.kernel.pdf.PdfWriter;
+import com.itextpdf.kernel.pdf.annot.PdfLinkAnnotation;
+import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
+import com.itextpdf.kernel.pdf.navigation.PdfExplicitDestination;
 import com.itextpdf.test.ExtendedITextTest;
 import com.itextpdf.test.annotations.LogMessage;
 import com.itextpdf.test.annotations.LogMessages;
 import com.itextpdf.test.annotations.type.IntegrationTest;
 
 import java.io.File;
+import java.io.IOException;
+import javax.xml.parsers.ParserConfigurationException;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Rule;
@@ -59,9 +71,6 @@ This file is part of the iText (R) project.
 import org.junit.rules.ExpectedException;
 import org.xml.sax.SAXException;
 
-import javax.xml.parsers.ParserConfigurationException;
-import java.io.IOException;
-
 @Category(IntegrationTest.class)
 public class CompareToolTest extends ExtendedITextTest {
 
@@ -218,4 +227,66 @@ public void compareVisuallyDiffTestTest() throws IOException, InterruptedExcepti
         Assert.assertTrue(new File(destinationFolder + "diff_1.png").exists());
         Assert.assertTrue(new File(destinationFolder + "diff_2.png").exists());
     }
+
+    @Test
+    public void compareDiffFilesWithSameLinkAnnotationTest() throws IOException {
+        String firstPdf = destinationFolder + "firstPdf.pdf";
+        String secondPdf = destinationFolder + "secondPdf.pdf";
+        PdfDocument firstDocument = new PdfDocument(new PdfWriter(firstPdf));
+
+        PdfPage page1FirstDocument = firstDocument.addNewPage();
+        PdfCanvas canvas = new PdfCanvas(page1FirstDocument);
+        canvas.beginText();
+        canvas.setFontAndSize(PdfFontFactory.createFont(StandardFonts.COURIER_BOLD), 14);
+        canvas.moveText(100, 600);
+        canvas.showText("Page 1");
+        canvas.moveText(0, -30);
+        canvas.showText("Link to page 1. Click here!");
+        canvas.endText();
+        canvas.release();
+        page1FirstDocument.addAnnotation(new PdfLinkAnnotation(new Rectangle(100, 560, 260, 25)).setDestination(
+                PdfExplicitDestination.createFit(page1FirstDocument)).setBorder(new PdfArray(new float[] {0, 0, 1})));
+        page1FirstDocument.flush();
+        firstDocument.close();
+
+        PdfDocument secondDocument = new PdfDocument(new PdfWriter(secondPdf));
+        PdfPage page1secondDocument = secondDocument.addNewPage();
+        canvas = new PdfCanvas(page1secondDocument);
+        canvas.beginText();
+        canvas.setFontAndSize(PdfFontFactory.createFont(StandardFonts.COURIER_BOLD), 14);
+        canvas.moveText(100, 600);
+        canvas.showText("Page 1 wit different Text");
+        canvas.moveText(0, -30);
+        canvas.showText("Link to page 1. Click here!");
+        canvas.endText();
+        canvas.release();
+        page1secondDocument.addAnnotation(new PdfLinkAnnotation(new Rectangle(100, 560, 260, 25)).setDestination(
+                PdfExplicitDestination.createFit(page1secondDocument)).setBorder(new PdfArray(new float[] {0, 0, 1})));
+        page1secondDocument.flush();
+        secondDocument.close();
+
+        Assert.assertNull(new CompareTool().compareLinkAnnotations(firstPdf, secondPdf));
+    }
+
+    @Test
+    public void compareFilesWithDiffLinkAnnotationTest() throws IOException {
+        String firstPdf = destinationFolder + "outPdf.pdf";
+        String secondPdf = destinationFolder + "secondPdf.pdf";
+        PdfDocument firstDocument = new PdfDocument(new PdfWriter(firstPdf));
+        PdfDocument secondDocument = new PdfDocument(new PdfWriter(secondPdf));
+
+        PdfPage page1FirstDocument = firstDocument.addNewPage();
+        page1FirstDocument.addAnnotation(new PdfLinkAnnotation(new Rectangle(100, 560, 400, 50)).setDestination(
+                PdfExplicitDestination.createFit(page1FirstDocument)).setBorder(new PdfArray(new float[] {0, 0, 1})));
+        page1FirstDocument.flush();
+        firstDocument.close();
+
+        PdfPage page1SecondDocument = secondDocument.addNewPage();
+        page1SecondDocument.addAnnotation(new PdfLinkAnnotation(new Rectangle(100, 560, 260, 25)).setDestination(
+                PdfExplicitDestination.createFit(page1SecondDocument)).setBorder(new PdfArray(new float[] {0, 0, 1})));
+        page1SecondDocument.flush();
+        secondDocument.close();
+
+        Assert.assertNotNull(new CompareTool().compareLinkAnnotations(firstPdf, secondPdf));
+    }
 }

kernel/src/test/java/com/itextpdf/kernel/utils/CompareToolTest.java

@@ -292,13 +292,15 @@ public void switchToPreviousRevision() throws IOException, GeneralSecurityExcept
         List<String> names = sgnUtil.getSignatureNames();
         if (names.size() > 1) {
             signatureName = names.get(names.size() - 2);
-            document = new PdfDocument(new PdfReader(sgnUtil.extractRevision(signatureName)), new DocumentProperties().setEventCountingMetaInfo(metaInfo));
+            try (PdfReader readerTmp = new PdfReader(sgnUtil.extractRevision(signatureName))) {
+            document = new PdfDocument(readerTmp, new DocumentProperties().setEventCountingMetaInfo(metaInfo));
             this.acroForm = PdfAcroForm.getAcroForm(document, true);
             this.sgnUtil = new SignatureUtil(document);
             names = sgnUtil.getSignatureNames();
             signatureName = names.get(names.size() - 1);
             pkcs7 = coversWholeDocument();
             LOGGER.info(MessageFormatUtil.format("Checking {0}signature {1}", pkcs7.isTsp() ? "document-level timestamp " : "", signatureName));
+            }
         }
         else {
             LOGGER.info("No signatures in revision");

kernel/src/test/resources/com/itextpdf/kernel/pdf/PdfEncryptorTest/initial.pdf

@@ -546,39 +546,40 @@ public static void createPdf(InputStream svgStream, OutputStream pdfDest, ISvgCo
         if (writerProps == null) {
             writerProps = new WriterProperties();
         }
-        PdfDocument pdfDocument = new PdfDocument(new PdfWriter(pdfDest, writerProps));
-        // Process
-        ISvgProcessorResult processorResult = process(parse(svgStream, props), props);
+        try (PdfWriter writer = new PdfWriter(pdfDest, writerProps);
+                PdfDocument pdfDocument = new PdfDocument(writer)) {
+            // Process
+            ISvgProcessorResult processorResult = process(parse(svgStream, props), props);
+
+            ResourceResolver resourceResolver = SvgConverter.getResourceResolver(processorResult, props);
+            SvgDrawContext drawContext = new SvgDrawContext(resourceResolver, processorResult.getFontProvider());
+            if (processorResult instanceof SvgProcessorResult) {
+                drawContext.setCssContext(((SvgProcessorResult) processorResult).getContext().getCssContext());
+            }
 
-        ResourceResolver resourceResolver = SvgConverter.getResourceResolver(processorResult, props);
-        SvgDrawContext drawContext = new SvgDrawContext(resourceResolver, processorResult.getFontProvider());
-        if (processorResult instanceof SvgProcessorResult) {
-            drawContext.setCssContext(((SvgProcessorResult) processorResult).getContext().getCssContext());
+            drawContext.addNamedObjects(processorResult.getNamedObjects());
+            // Add temp fonts
+            drawContext.setTempFonts(processorResult.getTempFonts());
+
+            ISvgNodeRenderer topSvgRenderer = processorResult.getRootRenderer();
+            // Extract topmost dimensions
+            checkNull(topSvgRenderer);
+            checkNull(pdfDocument);
+            float width, height;
+
+            float[] wh = extractWidthAndHeight(topSvgRenderer);
+            width = wh[0];
+            height = wh[1];
+
+            // Adjust pagesize and create new page
+            pdfDocument.setDefaultPageSize(new PageSize(width, height));
+            PdfPage page = pdfDocument.addNewPage();
+            PdfCanvas pageCanvas = new PdfCanvas(page);
+            // Add to the first page
+            PdfFormXObject xObject = convertToXObject(topSvgRenderer, pdfDocument, drawContext);
+            // Draw
+            draw(xObject, pageCanvas);
         }
-
-        drawContext.addNamedObjects(processorResult.getNamedObjects());
-        // Add temp fonts
-        drawContext.setTempFonts(processorResult.getTempFonts());
-
-        ISvgNodeRenderer topSvgRenderer = processorResult.getRootRenderer();
-        // Extract topmost dimensions
-        checkNull(topSvgRenderer);
-        checkNull(pdfDocument);
-        float width, height;
-
-        float[] wh = extractWidthAndHeight(topSvgRenderer);
-        width = wh[0];
-        height = wh[1];
-
-        // Adjust pagesize and create new page
-        pdfDocument.setDefaultPageSize(new PageSize(width, height));
-        PdfPage page = pdfDocument.addNewPage();
-        PdfCanvas pageCanvas = new PdfCanvas(page);
-        // Add to the first page
-        PdfFormXObject xObject = convertToXObject(topSvgRenderer, pdfDocument, drawContext);
-        // Draw
-        draw(xObject, pageCanvas);
-        pdfDocument.close();
     }
 
     /**