apk文件加壳的源代码

package com.android.dexshell;  
import java.io.ByteArrayOutputStream;  
import java.io.File;  
import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.security.MessageDigest;  
import java.security.NoSuchAlgorithmException;  
import java.util.zip.Adler32;  
  
public class DexShellTool {  
    /** 
     * @param args 
     */  
    public static void main(String[] args) {  
        // TODO Auto-generated method stub  
        try {  
 	   File payloadSrcFile = new File("g:/payload.apk");  
 	   File unShellDexFile = new File("g:/unshell.dex");  
 	   byte[] payloadArray = encrpt(readFileBytes(payloadSrcFile));  
 	   byte[] unShellDexArray = readFileBytes(unShellDexFile);  
 	   int payloadLen = payloadArray.length;  
 	   int unShellDexLen = unShellDexArray.length;  
 	   int totalLen = payloadLen + unShellDexLen +4;  
 	   byte[] newdex = new byte[totalLen];  
 	   //添加解壳代码  
 	   System.arraycopy(unShellDexArray, 0, newdex, 0, unShellDexLen);  
 	   //添加加密后的解壳数据  
 	   System.arraycopy(payloadArray, 0, newdex, unShellDexLen,  
 		   payloadLen);  
 	   //添加解壳数据长度  
 	   System.arraycopy(intToByte(payloadLen), 0, newdex, totalLen-4, 4);  
 		       //修改DEX file size文件头  
 	   fixFileSizeHeader(newdex);  
 	   //修改DEX SHA1 文件头  
 	   fixSHA1Header(newdex);  
 	   //修改DEX CheckSum文件头  
 	   fixCheckSumHeader(newdex);  
  
  
 	   String str = "g:/classes.dex";  
 	   File file = new File(str);  
 	   if (!file.exists()) {  
 	       file.createNewFile();  
 	   }  
 	     
 	   FileOutputStream localFileOutputStream = new FileOutputStream(str);  
 	   localFileOutputStream.write(newdex);  
 	   localFileOutputStream.flush();  
 	   localFileOutputStream.close();  
  
  
        } catch (Exception e) {  
 	   // TODO Auto-generated catch block  
 	   e.printStackTrace();  
        }  
    }  
      
    //直接返回数据，读者可以添加自己加密方法  
    private static byte[] encrpt(byte[] srcdata){  
        return srcdata;  
    }  
  
  
    private static void fixCheckSumHeader(byte[] dexBytes) {  
        Adler32 adler = new Adler32();  
        adler.update(dexBytes, 12, dexBytes.length - 12);  
        long value = adler.getValue();  
        int va = (int) value;  
        byte[] newcs = intToByte(va);  
        byte[] recs = new byte[4];  
        for (int i = 0; i = 0; i--) {  
 	   b[i] = (byte) (number % 256);  
 	   number >>= 8;  
        }  
        return b;  
    }  
  
  
    private static void fixSHA1Header(byte[] dexBytes)  
 	   throws NoSuchAlgorithmException {  
        MessageDigest md = MessageDigest.getInstance("SHA-1");  
        md.update(dexBytes, 32, dexBytes.length - 32);  
        byte[] newdt = md.digest();  
        System.arraycopy(newdt, 0, dexBytes, 12, 20);  
        String hexstr = "";  
        for (int i = 0; i < newdt.length; i++) {  
 	   hexstr += Integer.toString((newdt[i] & 0xff) + 0x100, 16)  
 		   .substring(1);  
        }  
        System.out.println(hexstr);  
    }  
  
  
    private static void fixFileSizeHeader(byte[] dexBytes) {  
  
  
        byte[] newfs = intToByte(dexBytes.length);  
        System.out.println(Integer.toHexString(dexBytes.length));  
        byte[] refs = new byte[4];  
        for (int i = 0; i < 4; i++) {  
 	   refs[i] = newfs[newfs.length - 1 - i];  
 	   System.out.println(Integer.toHexString(newfs[i]));  
        }  
        System.arraycopy(refs, 0, dexBytes, 32, 4);  
    }  
  
  
    private static byte[] readFileBytes(File file) throws IOException {  
        byte[] arrayOfByte = new byte[1024];  
        ByteArrayOutputStream localByteArrayOutputStream = new ByteArrayOutputStream();  
        FileInputStream fis = new FileInputStream(file);  
        while (true) {  
 	   int i = fis.read(arrayOfByte);  
 	   if (i != -1) {  
 	       localByteArrayOutputStream.write(arrayOfByte, 0, i);  
 	   } else {  
 	       return localByteArrayOutputStream.toByteArray();  
 	   }  
        }  
    }  
  
  
}