/*************************************************************************
 *                                                                       *
 *  CESeCore: CE Security Core                                           *
 *                                                                       *
 *  This software is free software; you can redistribute it and/or       *
 *  modify it under the terms of the GNU Lesser General Public           *
 *  License as published by the Free Software Foundation; either         *
 *  version 2.1 of the License, or any later version.                    *
 *                                                                       *
 *  See terms of license at gnu.org.                                     *
 *                                                                       *
 *************************************************************************/
package org.cesecore.util;

import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.security.cert.Certificate;
import java.security.cert.CertificateEncodingException;
import java.security.cert.CertificateParsingException;

import org.cesecore.certificates.certificate.CertificateWrapper;

/**
 * <p>Wrapper class for transmitting certificates over remote EJB. This wrapper is needed
 * because Java will always deserialize Certificate objects using the first security provider
 * configured on the system. That does not work with Certificates that use other signature
 * algorithms than the ones that are built into Java.</p>
 * 
 * <p>This class encodes and decodes the Certificate objects lazily only when serializing or
 * deserializing. So it should have a minimal performance impact.</p>
 * 
 * <p>This implementation shouldn't be used directly, and is package-internal.
 * You can create an instance of this class through {@link org.cesecore.util.EJBTools}.</p>
 * 
 * @version $Id: CertificateSerializableWrapper.java 23173 2016-04-12 14:54:52Z samuellb $
 */
final class CertificateSerializableWrapper implements CertificateWrapper, Serializable {

    private static final long serialVersionUID = 1L;

    private byte[] certificateBytes;
    private transient Certificate certificate = null;

    /**
     * Constructor is internal. Please use {@link org.cesecore.util.EJBTools#wrap(Certificate)} to create a wrapper.
     * @param certificate Certificate, non-null.
     */
    CertificateSerializableWrapper(final Certificate certificate) {
        if (certificate == null) {
            throw new IllegalStateException("Can't wrap null certificate");
        }
        this.certificate = certificate;
        this.certificateBytes = null;
    }
    
    @Override
    public Certificate getCertificate() {
        if (certificate == null && certificateBytes != null) {
            // Lazy restore in case of deserialization
            try {
                certificate = CertTools.getCertfromByteArray(certificateBytes, Certificate.class);
            } catch (CertificateParsingException e) {
                throw new IllegalStateException(e);
            }
        }
        return certificate;
    }
    
    private void writeObject(ObjectOutputStream stream) throws IOException {
        // Lazy encode before serialization
        if (certificateBytes == null) {
            try {
                certificateBytes = certificate.getEncoded();
            } catch (CertificateEncodingException e) {
                throw new IllegalStateException(e);
            }
        }
        stream.defaultWriteObject();
    }

}