de.schlichtherle.truezip.sample.file.RaesFiles Maven / Gradle / Ivy
/*
* Copyright (C) 2006-2011 Schlichtherle IT Services
*
* Licensed 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 de.schlichtherle.truezip.sample.file;
import de.schlichtherle.truezip.crypto.raes.param.KeyManagerRaesParameters;
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.file.TArchiveDetector;
import de.schlichtherle.truezip.file.TDefaultArchiveDetector;
import de.schlichtherle.truezip.file.TFile;
import de.schlichtherle.truezip.file.TFileInputStream;
import de.schlichtherle.truezip.file.TFileOutputStream;
import de.schlichtherle.truezip.key.sl.KeyManagerLocator;
import de.schlichtherle.truezip.rof.ReadOnlyFile;
import de.schlichtherle.truezip.rof.ReadOnlyFileInputStream;
import de.schlichtherle.truezip.rof.DefaultReadOnlyFile;
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
* @version $Id$
*/
public class 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, TFile.getDefaultArchiveDetector());
}
/**
* 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.
*/
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);
try {
final RaesOutputStream out = RaesOutputStream.getInstance(
new TFileOutputStream(raesFile, false),
params);
TFile.cp(in, out);
} finally {
in.close();
}
}
/**
* 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,
TFile.getDefaultArchiveDetector());
}
/**
* 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 strongAuthentication If this is {@code true}, the whole
* contents of encrypted file get authenticated, which can be a
* time consuming operation.
* Otherwise, only the key/password and the file length get
* authenticated.
*/
public static void decrypt(
final String raesFilePath,
final String plainFilePath,
final boolean strongAuthentication,
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 (strongAuthentication)
rrof.authenticate();
final InputStream in = new ReadOnlyFileInputStream(rrof);
final OutputStream out = new TFileOutputStream(plainFile, false);
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);
TFile parent = file.getParentFile();
assert null != parent : "expected non-null from context!";
return new TFile(parent, file.getName(), TDefaultArchiveDetector.NULL);
}
}