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Sample applications to demonstrate the usage of various TrueZIP module APIs. Some of these samples use rather advanced or exotic features which makes them more complex than necessary for a typical application. By design, the sample applications use all file system drivers which can be located at runtime. Location of the available file system drivers is performed by scanning the class path - see the Javaodoc for the TrueZIP Kernel class de.schlichtherle.truezip.fs.sl.FsDriverLocator for more information.

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/*
 * Copyright (C) 2005-2015 Schlichtherle IT Services.
 * All rights reserved. Use is subject to license terms.
 */
package de.schlichtherle.truezip.sample.file;

import de.schlichtherle.truezip.crypto.raes.RaesOutputStream;
import de.schlichtherle.truezip.crypto.raes.RaesParameters;
import de.schlichtherle.truezip.crypto.raes.RaesReadOnlyFile;
import de.schlichtherle.truezip.crypto.raes.param.KeyManagerRaesParameters;
import de.schlichtherle.truezip.file.*;
import de.schlichtherle.truezip.key.sl.KeyManagerLocator;
import de.schlichtherle.truezip.rof.DefaultReadOnlyFile;
import de.schlichtherle.truezip.rof.ReadOnlyFile;
import de.schlichtherle.truezip.rof.ReadOnlyFileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Saves and restores the contents of arbitrary files to and from the RAES
 * file format for encryption and decryption.
 * This class cannot get instantiated outside its package.
 * 
 * Note that this class is not intended to access RAES encrypted ZIP files -
 * use the {@link TFile} class for this task instead.
 *
 * @author  Christian Schlichtherle
 */
public class RaesFiles {

    /** You cannot instantiate this class. */
    private RaesFiles() {
    }

    /**
     * Encrypts the given plain file to the given RAES file.
     * This version uses the default TArchiveDetector to detect any archive
     * files in its parent directory path except the files themselves, which
     * are not recognized as archive files.
     */
    public static void encrypt(
            final String plainFilePath,
            final String raesFilePath)
    throws IOException {
        encrypt(plainFilePath, raesFilePath, TConfig.get().getArchiveDetector());
    }

    /**
     * Encrypts the given plain file to the given RAES file,
     * using the provided TArchiveDetector to detect any archive files in its
     * parent directory path except the files themselves, which are not
     * recognized as archive files.
     */
    @edu.umd.cs.findbugs.annotations.SuppressWarnings("OBL_UNSATISFIED_OBLIGATION")
    public static void encrypt(
            final String plainFilePath,
            final String raesFilePath,
            final TArchiveDetector detector)
    throws IOException {
        final TFile plainFile = newNonArchiveFile(plainFilePath, detector);
        final TFile raesFile = newNonArchiveFile(raesFilePath, detector);
        final RaesParameters params = new KeyManagerRaesParameters(
                KeyManagerLocator.SINGLETON,
                raesFile/*.getCanonicalFile()*/.toURI());
        final InputStream in = new TFileInputStream(plainFile);
        RaesOutputStream out = null;
        try {
            out = RaesOutputStream.getInstance(
                    new TFileOutputStream(raesFile, false),
                    params);
        } finally {
            if (null == out) // exception?
                in.close();
        }
        TFile.cp(in, out);
    }

    /**
     * Decrypts the given RAES file to the given plain file.
     * This version uses the default TArchiveDetector to detect any archive
     * files in its parent directory path except the files themselves, which
     * are not recognized as archive files.
     */
    public static void decrypt(
            final String raesFilePath,
            final String plainFilePath,
            final boolean strongAuthentication)
    throws IOException {
        decrypt(raesFilePath, plainFilePath, strongAuthentication,
                TConfig.get().getArchiveDetector());
    }

    /**
     * Decrypts the given RAES file to the given plain file,
     * using the provided TArchiveDetector to detect any archvie files in its
     * parent directory path except the files themselves, which are not
     * recognized as archive files.
     * 
     * @param authenticate If this is {@code true}, the entire contents of the
     *        encrypted file get authenticated, which can be a time consuming
     *        operation.
     *        Otherwise, only the key/password and the file length get
     *        authenticated.
     */
    @edu.umd.cs.findbugs.annotations.SuppressWarnings("OBL_UNSATISFIED_OBLIGATION")
    public static void decrypt(
            final String raesFilePath,
            final String plainFilePath,
            final boolean authenticate,
            final TArchiveDetector detector)
    throws IOException {
        final TFile raesFile = newNonArchiveFile(raesFilePath, detector);
        final TFile plainFile = newNonArchiveFile(plainFilePath, detector);
        final RaesParameters params = new KeyManagerRaesParameters(
                KeyManagerLocator.SINGLETON,
                raesFile/*.getCanonicalFile()*/.toURI());
        final ReadOnlyFile rof = new DefaultReadOnlyFile(raesFile);
        try {
            final RaesReadOnlyFile rrof
                    = RaesReadOnlyFile.getInstance(rof, params);
            if (authenticate)
                rrof.authenticate();
            final InputStream in = new ReadOnlyFileInputStream(rrof);
            OutputStream out = null;
            try {
                out = new TFileOutputStream(plainFile, false);
            } finally {
                if (null == out) // exception?
                    in.close();
            }
            TFile.cp(in, out);
        } finally {
            rof.close();
        }
    }

    /**
     * Creates a file object which uses the provided TArchiveDetector,
     * but does not recognize its own pathname as an archive file.
     * Please note that this method just creates a file object,
     * and does not actually operate on the file system.
     */
    private static TFile newNonArchiveFile(
            String path,
            TArchiveDetector detector) {
        TFile file = new TFile(path, detector);
        return new TFile(file.getParentFile(), file.getName(), TArchiveDetector.NULL);
    }
}