de.schlichtherle.truezip.fs.archive.zip.raes.ParanoidZipRaesDriver Maven / Gradle / Ivy

Go to download
/*
 * Copyright (C) 2006-2011 Schlichtherle IT Services
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package de.schlichtherle.truezip.fs.archive.zip.raes;

import de.schlichtherle.truezip.fs.FsModel;
import de.schlichtherle.truezip.fs.archive.zip.ZipArchiveEntry;
import de.schlichtherle.truezip.fs.archive.zip.ZipInputShop;
import de.schlichtherle.truezip.fs.archive.zip.ZipOutputShop;
import de.schlichtherle.truezip.key.KeyManagerProvider;
import de.schlichtherle.truezip.socket.IOPoolProvider;
import de.schlichtherle.truezip.socket.OutputShop;
import edu.umd.cs.findbugs.annotations.CheckForNull;
import edu.umd.cs.findbugs.annotations.DefaultAnnotation;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.io.IOException;
import java.io.OutputStream;
import net.jcip.annotations.Immutable;

/**
 * A paranoid archive driver which builds RAES encrypted ZIP files.
 * This driver always checks the cipher text of input archive files
 * using the RAES Message Authentication Code (MAC), which makes it slower than
 * the {@link SafeZipRaesDriver} for archive files larger than 512 KB and
 * may pause the client application on the first access to the archive file
 * for a while if the file is large.
 * Note that the CRC-32 value of the plain text ZIP file is never checked
 * because this is made redundant by the MAC verification.
 * 
 * In addition, this driver limits the number of concurrent entry output
 * streams to one, so that writing unencrypted temporary files is inhibited.
 * 
 * @see     SafeZipRaesDriver
 * @author  Christian Schlichtherle
 * @version $Id$
 */
@Immutable
@DefaultAnnotation(NonNull.class)
public class ParanoidZipRaesDriver extends ZipRaesDriver {

    public ParanoidZipRaesDriver(   IOPoolProvider ioPoolProvider,
                                    KeyManagerProvider keyManagerProvider) {
        super(ioPoolProvider, keyManagerProvider);
    }

    @Override
    public final long getAuthenticationTrigger() {
        return Long.MAX_VALUE;
    }

    /**
     * This implementation returns a new {@link ZipOutputShop}.
     * This restricts the number of concurrent output entry streams to one in
     * order to inhibit writing unencrypted temporary files for buffering the
     * written entries.
     */
    @Override
    protected OutputShop newOutputShop(
            FsModel model,
            OutputStream out,
            @CheckForNull ZipInputShop source)
    throws IOException {
        return new ZipOutputShop(this, model, out, source);
    }
}