/**
 * 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
 *
 * http://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.xml.security.test.stax.encryption;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.lang.reflect.Constructor;
import java.nio.charset.StandardCharsets;
import java.security.Key;
import java.security.Provider;
import java.security.Security;
import java.util.ArrayList;
import java.util.List;

import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;

import org.apache.xml.security.encryption.XMLCipher;
import org.apache.xml.security.stax.ext.OutboundXMLSec;
import org.apache.xml.security.stax.ext.SecurePart;
import org.apache.xml.security.stax.ext.XMLSec;
import org.apache.xml.security.stax.ext.XMLSecurityConstants;
import org.apache.xml.security.stax.ext.XMLSecurityProperties;
import org.apache.xml.security.test.stax.utils.XMLSecEventAllocator;
import org.apache.xml.security.test.stax.utils.XmlReaderToWriter;
import org.apache.xml.security.utils.XMLUtils;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.Assumptions;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import static org.junit.jupiter.api.Assertions.assertEquals;

/**
 * A test to make sure that the various Symmetric Encryption algorithms are working
 */
class SymmetricEncryptionCreationTest {

    private static boolean bcInstalled;
    private final XMLInputFactory xmlInputFactory;

    @BeforeAll
    public static void setup() throws Exception {
        //
        // If the BouncyCastle provider is not installed, then try to load it
        // via reflection.
        //
        if (Security.getProvider("BC") == null) {
            Constructor<?> cons = null;
            try {
                Class<?> c = Class.forName("org.bouncycastle.jce.provider.BouncyCastleProvider");
                cons = c.getConstructor(new Class[] {});
            } catch (Exception e) {
                //ignore
            }
            if (cons != null) {
                Provider provider = (Provider)cons.newInstance();
                Security.insertProviderAt(provider, 2);
                bcInstalled = true;
            }
        }
    }

    public SymmetricEncryptionCreationTest() throws Exception {
        org.apache.xml.security.Init.init();

        xmlInputFactory = XMLInputFactory.newInstance();
        xmlInputFactory.setEventAllocator(new XMLSecEventAllocator());
    }

    @AfterAll
    public static void cleanup() throws Exception {
        Security.removeProvider("BC");
    }

    @Test
    void testAES128() throws Exception {
        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("AES");
        keygen.init(128);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2001/04/xmlenc#aes128-cbc";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 1);
    }

    @Test
    void testAES128_GCM() throws Exception {
        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("AES");
        keygen.init(128);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2009/xmlenc11#aes128-gcm";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 1);
    }

    @Test
    void testAES192() throws Exception {
        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("AES");
        keygen.init(192);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2001/04/xmlenc#aes192-cbc";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 1);
    }

    @Test
    void testAES192_GCM() throws Exception {
        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("AES");
        keygen.init(192);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2009/xmlenc11#aes192-gcm";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 1);
    }

    @Test
    void testAES256() throws Exception {
        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("AES");
        keygen.init(256);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2001/04/xmlenc#aes256-cbc";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 1);
    }

    @Test
    void testAES256_GCM() throws Exception {
        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("AES");
        keygen.init(256);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2009/xmlenc11#aes256-gcm";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 1);
    }

    @Test
    void testTRIPLE_DES() throws Exception {
        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("DESede");
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2001/04/xmlenc#tripledes-cbc";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 1);
    }

    @Test
    void testSEED_128() throws Exception {
        Assumptions.assumeTrue(bcInstalled);

        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("SEED");
        keygen.init(128);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2007/05/xmldsig-more#seed128-cbc";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
    }

    @Test
    void testCAMELLIA_128() throws Exception {
        Assumptions.assumeTrue(bcInstalled);

        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("Camellia");
        keygen.init(128);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2001/04/xmldsig-more#camellia128-cbc";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
    }

    @Test
    void testCAMELLIA_192() throws Exception {
        Assumptions.assumeTrue(bcInstalled);

        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("Camellia");
        keygen.init(192);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2001/04/xmldsig-more#camellia192-cbc";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
    }

    @Test
    void testCAMELLIA_256() throws Exception {
        Assumptions.assumeTrue(bcInstalled);

        // Set up the Configuration
        XMLSecurityProperties properties = new XMLSecurityProperties();
        List<XMLSecurityConstants.Action> actions = new ArrayList<>();
        actions.add(XMLSecurityConstants.ENCRYPTION);
        properties.setActions(actions);

        // Set the key up
        KeyGenerator keygen = KeyGenerator.getInstance("Camellia");
        keygen.init(256);
        SecretKey key = keygen.generateKey();
        properties.setEncryptionKey(key);

        String algorithm = "http://www.w3.org/2001/04/xmldsig-more#camellia256-cbc";
        properties.setEncryptionSymAlgorithm(algorithm);

        SecurePart securePart =
               new SecurePart(new QName("urn:example:po", "PaymentInfo"), SecurePart.Modifier.Element);
        properties.addEncryptionPart(securePart);

        byte[] output = process("ie/baltimore/merlin-examples/merlin-xmlenc-five/plaintext.xml", properties);
        // System.out.println("Got:\n" + new String(output, StandardCharsets.UTF_8));
        Document document;
        try (InputStream is = new ByteArrayInputStream(output)) {
            document = XMLUtils.read(is, false);
        }

        NodeList nodeList = document.getElementsByTagNameNS("urn:example:po", "PaymentInfo");
        assertEquals(nodeList.getLength(), 0);

        // Check the CreditCard encrypted ok
        nodeList = document.getElementsByTagNameNS("urn:example:po", "CreditCard");
        assertEquals(nodeList.getLength(), 0);

        nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        assertEquals(nodeList.getLength(), 1);

        // Decrypt using DOM API
        Document doc = decryptUsingDOM(algorithm, key, null, document);

        // Check the CreditCard decrypted ok
        nodeList = doc.getElementsByTagNameNS("urn:example:po", "CreditCard");
    }

    private byte[] process(String xmlFile, XMLSecurityProperties properties) throws Exception {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        OutboundXMLSec outboundXMLSec = XMLSec.getOutboundXMLSec(properties);
        XMLStreamWriter xmlStreamWriter = outboundXMLSec.processOutMessage(baos, StandardCharsets.UTF_8.name());
        try (InputStream sourceDocument = this.getClass().getClassLoader().getResourceAsStream(xmlFile)) {
            XMLStreamReader xmlStreamReader = xmlInputFactory.createXMLStreamReader(sourceDocument);
            XmlReaderToWriter.writeAllAndClose(xmlStreamReader, xmlStreamWriter);
        }
        return baos.toByteArray();
    }

    /**
     * Decrypt the document using DOM API and run some tests on the decrypted Document.
     */
    private Document decryptUsingDOM(
        String algorithm,
        SecretKey secretKey,
        Key wrappingKey,
        Document document
    ) throws Exception {
        XMLCipher cipher = XMLCipher.getInstance(algorithm);
        cipher.init(XMLCipher.DECRYPT_MODE, secretKey);
        if (wrappingKey != null) {
            cipher.setKEK(wrappingKey);
        }

        NodeList nodeList = document.getElementsByTagNameNS(
                XMLSecurityConstants.TAG_xenc_EncryptedData.getNamespaceURI(),
                XMLSecurityConstants.TAG_xenc_EncryptedData.getLocalPart()
            );
        Element ee = (Element)nodeList.item(0);
        return cipher.doFinal(document, ee);
    }

}