/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.commons.xml.secure;
  
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  
  import java.io.ByteArrayInputStream;
  import java.io.InputStream;
  import java.nio.charset.StandardCharsets;
  
  import javax.xml.bind.JAXBContext;
  import javax.xml.bind.Unmarshaller;
  import javax.xml.bind.annotation.XmlRootElement;
  import javax.xml.parsers.SAXParserFactory;
  import javax.xml.stream.XMLInputFactory;
  import javax.xml.stream.XMLStreamReader;
  import javax.xml.transform.sax.SAXSource;
  
  import org.junit.jupiter.api.Test;
  import org.xml.sax.InputSource;
  import org.xml.sax.XMLReader;
  
  /**
   * Tests JAXB integration.
   * <p>
   * This class' two public methods serve as examples for the Javadoc {@code overview.html} file.
   * </p>
   */
  public class JaxbTest {
  
      @XmlRootElement
      static class MyJaxbModel {
          // JAXB model fields and methods
      }
  
      @Test
      void testUnmarshalSecurelyWithSax() throws Exception {
          try (InputStream xmlStream = new ByteArrayInputStream("<myJaxbModel/>".getBytes(StandardCharsets.UTF_8))) {
              assertNotNull(new JaxbTest().unmarshalSecurelyWithSax(xmlStream));
          }
      }
  
      @Test
      void testUnmarshalSecurelyWithStax() throws Exception {
          try (InputStream xmlStream = new ByteArrayInputStream("<myJaxbModel/>".getBytes(StandardCharsets.UTF_8))) {
              assertNotNull(new JaxbTest().unmarshalSecurelyWithStax(xmlStream));
          }
      }
  
      public MyJaxbModel unmarshalSecurelyWithSax(final InputStream xmlStream) throws Exception {
          final JAXBContext context = JAXBContext.newInstance(MyJaxbModel.class);
          final Unmarshaller unmarshaller = context.createUnmarshaller();
          // Create a secure SAXParserFactory via Apache Commons Secure XML
          final SAXParserFactory spf = SecureSAXParserFactory.newDefaultNSInstance();
          // Generate a hardened XMLReader and wrap the input source
          final XMLReader xmlReader = spf.newSAXParser().getXMLReader();
          final SAXSource source = new SAXSource(xmlReader, new InputSource(xmlStream));
          // With the default resolver configuration, external DTDs and entities are prevented from being fetched or resolved, protecting against XXE attacks, protecting against XXE attacks.
          // Entity-expansion limits use FEATURE_SECURE_PROCESSING on JDK parsers;
          // Android support is implementation-dependent and best-effort.
          return (MyJaxbModel) unmarshaller.unmarshal(source);
      }
  
      public MyJaxbModel unmarshalSecurelyWithStax(final InputStream xmlStream) throws Exception {
          final JAXBContext context = JAXBContext.newInstance(MyJaxbModel.class);
          final Unmarshaller unmarshaller = context.createUnmarshaller();
          // Create a secure XMLInputFactory via Apache Commons Secure XML
          final XMLInputFactory xif = SecureXMLInputFactory.newDefaultFactory();
          // Create a hardened cursor reader
          final XMLStreamReader xmlReader = xif.createXMLStreamReader(xmlStream);
          try {
              // With the default resolver configuration, external DTDs and entities are prevented from being fetched or resolved, protecting against XXE attacks, protecting against XXE attacks.
              // Entity-expansion protection is implementation-dependent and best-effort
              // because StAX exposes no secure-processing feature.
              return (MyJaxbModel) unmarshaller.unmarshal(xmlReader);
          } finally {
              xmlReader.close();
          }
      }
  }