de.rub.syssec.saaf.analysis.steps.extract.ApkUnzipper.java Source code

Introduction

Here is the source code for de.rub.syssec.saaf.analysis.steps.extract.ApkUnzipper.java

Source

/* SAAF: A static analyzer for APK files.
 * Copyright (C) 2013  syssec.rub.de
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package de.rub.syssec.saaf.analysis.steps.extract;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import org.apache.commons.io.FileUtils;
import org.apache.log4j.Logger;

public class ApkUnzipper {

    private static final Logger LOGGER = Logger.getLogger(ApkUnzipper.class);

    /**
     * Extracts the given archive into the given destination directory
     * 
     * @param archive
     *            - the file to extract
     * @param dest
     *            - the destination directory
     * @throws Exception
     */
    public static void extractArchive(File archive, File destDir) throws IOException {

        if (!destDir.exists()) {
            destDir.mkdir();
        }

        ZipFile zipFile = new ZipFile(archive);
        Enumeration<? extends ZipEntry> entries = zipFile.entries();

        byte[] buffer = new byte[16384];
        int len;
        while (entries.hasMoreElements()) {
            ZipEntry entry = entries.nextElement();

            String entryFileName = entry.getName();

            File dir = buildDirectoryHierarchyFor(entryFileName, destDir);
            if (!dir.exists()) {
                dir.mkdirs();
            }

            if (!entry.isDirectory()) {

                File file = new File(destDir, entryFileName);

                BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file));

                BufferedInputStream bis = new BufferedInputStream(zipFile.getInputStream(entry));

                while ((len = bis.read(buffer)) > 0) {
                    bos.write(buffer, 0, len);
                }

                bos.flush();
                bos.close();
                bis.close();
            }
        }
        zipFile.close();
    }

    /**
     * Copies the given file into the given destination directory
     * 
     * @param archive
     *            - the file to copy
     * @param dest
     *            - the destination directory
     * @throws IOException
     */
    public static void copyApk(File archive, File dest) throws IOException {

        File destination = new File(dest, archive.getName());
        FileUtils.copyFile(archive, destination);
    }

    /**
     * Extracts the given apk into the given destination directory
     * 
     * @param archive
     *            - the file to extract
     * @param dest
     *            - the destination directory
     * @throws IOException
     */
    public static void extractApk(File archive, File dest) throws IOException {

        @SuppressWarnings("resource") // Closing it later results in an error
        ZipFile zipFile = new ZipFile(archive);
        Enumeration<? extends ZipEntry> entries = zipFile.entries();
        BufferedOutputStream bos = null;
        BufferedInputStream bis = null;

        while (entries.hasMoreElements()) {
            ZipEntry entry = entries.nextElement();

            String entryFileName = entry.getName();

            byte[] buffer = new byte[16384];
            int len;

            File dir = buildDirectoryHierarchyFor(entryFileName, dest);// destDir
            if (!dir.exists()) {
                dir.mkdirs();
            }

            if (!entry.isDirectory()) {
                if (entry.getSize() == 0) {
                    LOGGER.warn("Found ZipEntry \'" + entry.getName() + "\' with size 0 in " + archive.getName()
                            + ". Looks corrupted.");
                    continue;
                }

                try {
                    bos = new BufferedOutputStream(new FileOutputStream(new File(dest, entryFileName)));// destDir,...

                    bis = new BufferedInputStream(zipFile.getInputStream(entry));

                    while ((len = bis.read(buffer)) > 0) {
                        bos.write(buffer, 0, len);
                    }
                    bos.flush();
                } catch (IOException ioe) {
                    LOGGER.warn("Failed to extract entry \'" + entry.getName() + "\' from archive. Results for "
                            + archive.getName() + " may not be accurate");
                } finally {
                    if (bos != null)
                        bos.close();
                    if (bis != null)
                        bis.close();
                    // if (zipFile != null) zipFile.close();
                }
            }

        }

    }

    private static File buildDirectoryHierarchyFor(String entryName, File destDir) {
        int lastIndex = entryName.lastIndexOf('/');

        String internalPathToEntry = entryName.substring(0, lastIndex + 1);
        return new File(destDir, internalPathToEntry);
    }
}