changeset 22991:ed73cb1663a5

8034087: XML parser may overwrite element content if that content falls onto the border of an entity scanner buffer Reviewed-by: alanb, joehw Contributed-by: steffen.schreiber@sap.com
author simonis
date Thu, 20 Feb 2014 10:40:58 +0100
parents daa64fcb5ba7
children e7fcc52b1b29
files jdk/test/javax/xml/jaxp/parsers/8027359/FragmentScannerBufferLimitTest.java
diffstat 1 files changed, 159 insertions(+), 0 deletions(-) [+]
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/xml/jaxp/parsers/8027359/FragmentScannerBufferLimitTest.java	Thu Feb 20 10:40:58 2014 +0100
@@ -0,0 +1,159 @@
+/*
+ * Copyright 2014, SAP AG. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8034087 8027359
+ * @summary XML parser may overwrite element content if that content falls onto the border of an entity scanner buffer
+ * @run main FragmentScannerBufferLimitTest
+ */
+import java.io.*;
+
+import javax.xml.parsers.*;
+import javax.xml.transform.*;
+import org.w3c.dom.*;
+import org.xml.sax.*;
+
+/**
+ * Test for overwriting of XML element content by the XML parser when reading over buffer
+ * limits.
+ *
+ * We create a simple XML document of the form:
+ *
+ * <?xml version=\"1.1\"?>
+ * <ROOT>
+ *    <FILLER>ffffffff...fffff</FILLER>
+ *    <TEST>content</TEST><TEST2>content2</TEST2>
+ *    <FILLER>ffffffff...fffffffff</FILLER>
+ * </ROOT>
+ *
+ * What's important here is, that the test content is at the border of an entity scanner
+ * buffer (XMLEntityScanner uses 8192 byte buffers). That's why there are filler elements
+ * of sufficient length that ensure there is a buffer break inside the test content
+ * and there is enough to read to require another buffer read after the content has been
+ * read.
+ *
+ * With the faulty implementation, the test content gets overwritten with characters
+ * read from the next buffer, i.e. 'f's.
+ *
+ * @author steffen.schreiber@sap.com
+ */
+public class FragmentScannerBufferLimitTest {
+
+    static int errCount = 0;
+
+    /**
+     * Check the test content.
+     */
+    public static void main(String[] args) throws ParserConfigurationException,
+            SAXException, IOException, TransformerConfigurationException,
+            TransformerException, TransformerFactoryConfigurationError {
+
+        String testString = "<TEST>content</TEST><TEST2>content2</TEST2>";
+
+        for (int i = 0; i < testString.length(); i++) {
+            test(createDocument(testString.toString(), i), ""+ i);
+        }
+
+        if (errCount == 0) {
+            System.out.println("OK");
+        }
+        else {
+            System.out.println("ERROR");
+            throw new RuntimeException("Parsing error: element content has been overwritten");
+        }
+    }
+
+    /**
+     * Create the test XML document.
+     * @param testString the test content string
+     * @param bufferLimitPosition the position in the string where the buffer should break
+     * @return the document
+     */
+    private static String createDocument(String testString, int bufferLimitPosition) throws UnsupportedEncodingException {
+        StringBuilder result = new StringBuilder();
+        result.append("<?xml version=\"1.1\"?>");
+        result.append("<ROOT>");
+
+        int fillerLength = 8192 - bufferLimitPosition;
+        createFiller(result, fillerLength);
+
+        result.append(testString);
+
+        createFiller(result, 9000);
+        result.append("</ROOT>");
+        return result.toString();
+    }
+
+    /**
+     * Create the filler element of the given length.
+     * @param buffer the output buffer
+     * @param length the required length of the element, including the element tags
+     */
+    private static void createFiller(StringBuilder buffer, int length) {
+        buffer.append("<FILLER>");
+        int fillLength = length - "<FILLER></FILLER>".length();
+        for (int i=0; i<fillLength; i++) {
+            buffer.append('f');
+        }
+        buffer.append("</FILLER>");
+    }
+
+
+    private static void test(String document, String testName) throws SAXException, IOException, ParserConfigurationException {
+        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+        DocumentBuilder builder = factory.newDocumentBuilder();
+
+        Document doc = builder.parse(new ByteArrayInputStream(document.getBytes("UTF-8")));
+
+        // check that there is the root node
+        NodeList roots = doc.getElementsByTagName("ROOT");
+        assert roots.getLength() == 1;
+        Node root = roots.item(0);
+
+        // check that root has children "FILLER" and "TEST"
+        NodeList children = root.getChildNodes();
+        assert children.getLength() == 4;
+        assert children.item(0).getNodeName().equals("FILLER");
+        assert children.item(1).getNodeName().equals("TEST");
+        assert children.item(2).getNodeName().equals("TEST2");
+        assert children.item(3).getNodeName().equals("FILLER");
+
+        // check that the test node has content "content"
+        checkContent(children.item(1).getTextContent(), "content", document);
+        checkContent(children.item(2).getTextContent(), "content2", document);
+    }
+
+    private static void checkContent(String found, String expected, String document) {
+        if (! (found.equals(expected))) {
+            errCount++;
+            int bufferStart = "<?xml version=\"1.1\"?><ROOT>".length() +1;
+            int bufferStart2 = bufferStart + 8192;
+            System.err.println("\nError:: expected \"" + expected
+                    + "\", but found \"" + found + "\"!");
+            System.err.println("Buffer was (probably): [ ... "
+                    + document.substring(bufferStart2 - 20, bufferStart2) + "] ["
+                    + document.substring(bufferStart2, bufferStart2 + 30) + " ... ]");
+        }
+    }
+}