/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
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.
/**
 * 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.
 */
/*
 * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * $Id: DOMX509Data.java 1854026 2019-02-21 09:30:01Z coheigea $
 */
package org.jcp.xml.dsig.internal.dom;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.security.cert.*;
import java.util.*;

import javax.security.auth.x500.X500Principal;
import javax.xml.crypto.MarshalException;
import javax.xml.crypto.XMLStructure;
import javax.xml.crypto.dom.DOMCryptoContext;
import javax.xml.crypto.dsig.XMLSignature;
import javax.xml.crypto.dsig.keyinfo.X509Data;
import javax.xml.crypto.dsig.keyinfo.X509IssuerSerial;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

import com.sun.org.apache.xml.internal.security.utils.XMLUtils;

DOM-based implementation of X509Data.
/**
 * DOM-based implementation of X509Data.
 *
 */
//@@@ check for illegal combinations of data violating MUSTs in W3c spec
public final class DOMX509Data extends DOMStructure implements X509Data {

    private final List<Object> content;
    private CertificateFactory cf;

    
Creates a DOMX509Data.
Params:
content – a list of one or more X.509 data types. Valid types are String (subject names), byte[] (subject key ids), X509Certificate, X509CRL, or XMLStructure objects or elements from an external namespace). The list is defensively copied to protect against subsequent modification.
Throws:
NullPointerException – if content is null
IllegalArgumentException – if content is empty
ClassCastException – if content contains any entries that are not of one of the valid types mentioned above/**
     * Creates a DOMX509Data.
     *
     * @param content a list of one or more X.509 data types. Valid types are
     *    {@link String} (subject names), {@code byte[]} (subject key ids),
     *    {@link java.security.cert.X509Certificate}, {@link X509CRL},
     *    or {@link javax.xml.dsig.XMLStructure}
     *    objects or elements from an external namespace). The list is
     *    defensively copied to protect against subsequent modification.
     * @throws NullPointerException if {@code content} is {@code null}
     * @throws IllegalArgumentException if {@code content} is empty
     * @throws ClassCastException if {@code content} contains any entries
     *    that are not of one of the valid types mentioned above
     */
    public DOMX509Data(List<?> content) {
        if (content == null) {
            throw new NullPointerException("content cannot be null");
        }
        List<Object> contentCopy = new ArrayList<>(content);
        if (contentCopy.isEmpty()) {
            throw new IllegalArgumentException("content cannot be empty");
        }
        for (int i = 0, size = contentCopy.size(); i < size; i++) {
            Object x509Type = contentCopy.get(i);
            if (x509Type instanceof String) {
                new X500Principal((String)x509Type);
            } else if (!(x509Type instanceof byte[]) &&
                !(x509Type instanceof X509Certificate) &&
                !(x509Type instanceof X509CRL) &&
                !(x509Type instanceof XMLStructure)) {
                throw new ClassCastException
                    ("content["+i+"] is not a valid X509Data type");
            }
        }
        this.content = Collections.unmodifiableList(contentCopy);
    }

    
Creates a DOMX509Data from an element. 
Params:
xdElem – an X509Data element
Throws:
MarshalException – if there is an error while unmarshalling/**
     * Creates a {@code DOMX509Data} from an element.
     *
     * @param xdElem an X509Data element
     * @throws MarshalException if there is an error while unmarshalling
     */
    public DOMX509Data(Element xdElem) throws MarshalException {
        // get all children nodes
        List<Object> newContent = new ArrayList<>();
        Node firstChild = xdElem.getFirstChild();
        while (firstChild != null) {
            if (firstChild.getNodeType() == Node.ELEMENT_NODE) {
                Element childElem = (Element)firstChild;
                String localName = childElem.getLocalName();
                String namespace = childElem.getNamespaceURI();
                if ("X509Certificate".equals(localName) && XMLSignature.XMLNS.equals(namespace)) {
                    newContent.add(unmarshalX509Certificate(childElem));
                } else if ("X509IssuerSerial".equals(localName) && XMLSignature.XMLNS.equals(namespace)) {
                    newContent.add(new DOMX509IssuerSerial(childElem));
                } else if ("X509SubjectName".equals(localName) && XMLSignature.XMLNS.equals(namespace)) {
                    newContent.add(childElem.getFirstChild().getNodeValue());
                } else if ("X509SKI".equals(localName) && XMLSignature.XMLNS.equals(namespace)) {
                    String content = XMLUtils.getFullTextChildrenFromNode(childElem);
                    newContent.add(XMLUtils.decode(content));
                } else if ("X509CRL".equals(localName) && XMLSignature.XMLNS.equals(namespace)) {
                    newContent.add(unmarshalX509CRL(childElem));
                } else {
                    newContent.add(new javax.xml.crypto.dom.DOMStructure(childElem));
                }
            }
            firstChild = firstChild.getNextSibling();
        }
        this.content = Collections.unmodifiableList(newContent);
    }

    public List<Object> getContent() {
        return content;
    }

    @Override
    public void marshal(Node parent, String dsPrefix, DOMCryptoContext context)
        throws MarshalException
    {
        Document ownerDoc = DOMUtils.getOwnerDocument(parent);
        Element xdElem = DOMUtils.createElement(ownerDoc, "X509Data",
                                                XMLSignature.XMLNS, dsPrefix);

        // append children and preserve order
        for (int i = 0, size = content.size(); i < size; i++) {
            Object object = content.get(i);
            if (object instanceof X509Certificate) {
                marshalCert((X509Certificate)object,xdElem,ownerDoc,dsPrefix);
            } else if (object instanceof XMLStructure) {
                if (object instanceof X509IssuerSerial) {
                    ((DOMX509IssuerSerial)object).marshal
                        (xdElem, dsPrefix, context);
                } else {
                    javax.xml.crypto.dom.DOMStructure domContent =
                        (javax.xml.crypto.dom.DOMStructure)object;
                    DOMUtils.appendChild(xdElem, domContent.getNode());
                }
            } else if (object instanceof byte[]) {
                marshalSKI((byte[])object, xdElem, ownerDoc, dsPrefix);
            } else if (object instanceof String) {
                marshalSubjectName((String)object, xdElem, ownerDoc,dsPrefix);
            } else if (object instanceof X509CRL) {
                marshalCRL((X509CRL)object, xdElem, ownerDoc, dsPrefix);
            }
        }

        parent.appendChild(xdElem);
    }

    private void marshalSKI(byte[] skid, Node parent, Document doc,
                            String dsPrefix)
    {
        Element skidElem = DOMUtils.createElement(doc, "X509SKI",
                                                  XMLSignature.XMLNS, dsPrefix);
        skidElem.appendChild(doc.createTextNode(XMLUtils.encodeToString(skid)));
        parent.appendChild(skidElem);
    }

    private void marshalSubjectName(String name, Node parent, Document doc,
                                    String dsPrefix)
    {
        Element snElem = DOMUtils.createElement(doc, "X509SubjectName",
                                                XMLSignature.XMLNS, dsPrefix);
        snElem.appendChild(doc.createTextNode(name));
        parent.appendChild(snElem);
    }

    private void marshalCert(X509Certificate cert, Node parent, Document doc,
                             String dsPrefix)
        throws MarshalException
    {
        Element certElem = DOMUtils.createElement(doc, "X509Certificate",
                                                  XMLSignature.XMLNS, dsPrefix);
        try {
            certElem.appendChild(doc.createTextNode
                                 (XMLUtils.encodeToString(cert.getEncoded())));
        } catch (CertificateEncodingException e) {
            throw new MarshalException("Error encoding X509Certificate", e);
        }
        parent.appendChild(certElem);
    }

    private void marshalCRL(X509CRL crl, Node parent, Document doc,
                            String dsPrefix)
        throws MarshalException
    {
        Element crlElem = DOMUtils.createElement(doc, "X509CRL",
                                                 XMLSignature.XMLNS, dsPrefix);
        try {
            crlElem.appendChild(doc.createTextNode
                                (XMLUtils.encodeToString(crl.getEncoded())));
        } catch (CRLException e) {
            throw new MarshalException("Error encoding X509CRL", e);
        }
        parent.appendChild(crlElem);
    }

    private X509Certificate unmarshalX509Certificate(Element elem)
        throws MarshalException
    {
        try (ByteArrayInputStream bs = unmarshalBase64Binary(elem)) {
            return (X509Certificate)cf.generateCertificate(bs);
        } catch (CertificateException e) {
            throw new MarshalException("Cannot create X509Certificate", e);
        } catch (IOException e) {
            throw new MarshalException("Error closing stream", e);
        }
    }

    private X509CRL unmarshalX509CRL(Element elem) throws MarshalException {
        try (ByteArrayInputStream bs = unmarshalBase64Binary(elem)) {
            return (X509CRL)cf.generateCRL(bs);
        } catch (CRLException e) {
            throw new MarshalException("Cannot create X509CRL", e);
        } catch (IOException e) {
            throw new MarshalException("Error closing stream", e);
        }
    }

    private ByteArrayInputStream unmarshalBase64Binary(Element elem)
        throws MarshalException {
        try {
            if (cf == null) {
                cf = CertificateFactory.getInstance("X.509");
            }
            String content = XMLUtils.getFullTextChildrenFromNode(elem);
            return new ByteArrayInputStream(XMLUtils.decode(content));
        } catch (CertificateException e) {
            throw new MarshalException("Cannot create CertificateFactory", e);
        }
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }

        if (!(o instanceof X509Data)) {
            return false;
        }
        X509Data oxd = (X509Data)o;

        List<?> ocontent = oxd.getContent();
        int size = content.size();
        if (size != ocontent.size()) {
            return false;
        }

        for (int i = 0; i < size; i++) {
            Object x = content.get(i);
            Object ox = ocontent.get(i);
            if (x instanceof byte[]) {
                if (!(ox instanceof byte[]) ||
                    !Arrays.equals((byte[])x, (byte[])ox)) {
                    return false;
                }
            } else {
                if (!(x.equals(ox))) {
                    return false;
                }
            }
        }

        return true;
    }

    @Override
    public int hashCode() {
        int result = 17;
        result = 31 * result + content.hashCode();

        return result;
    }
}