성능 최적화 (7) APK 보강 Dex 복호화, 역컴파일은 프로젝트의 주요 코드를 볼 수 없습니다.

android {
    defaultConfig {
        ...
        minSdkVersion 21 
        targetSdkVersion 28
        multiDexEnabled true
    }
    ...
}

android {
    defaultConfig {
        ...
        minSdkVersion 15 
        targetSdkVersion 28
        multiDexEnabled true
    }
    ...
}

dependencies {
  compile 'com.android.support:multidex:1.0.3'
}

//        APK  
File apkFile=new File(getApplicationInfo().sourceDir);
// apk     app_name+"_"+app_version        boot     
File versionDir = getDir(app_name+"_"+app_version,MODE_PRIVATE);
File appDir=new File(versionDir,"app");
File dexDir=new File(appDir,"dexDir");

// apk   appDir
Zip.unZip(apkFile,appDir);
//          
File[] files=appDir.listFiles();
for (File file : files) {
     String name=file.getName();
     if(name.endsWith(".dex") && !TextUtils.equals(name,"classes.dex")){
     try{
        AES.init(AES.DEFAULT_PWD);
        //      
        byte[] bytes=Utils.getBytes(file);
        //  
        byte[] decrypt=AES.decrypt(bytes);
        //       
        FileOutputStream fos=new FileOutputStream(file);
        fos.write(decrypt);
        fos.flush();
        fos.close();
        dexFiles.add(file);

     }catch (Exception e){
         e.printStackTrace();
     }
  }
}

private void loadDex(List dexFiles, File versionDir) throws Exception{
        //1.  pathlist
        Field pathListField = Utils.findField(getClassLoader(), "pathList");
        Object pathList = pathListField.get(getClassLoader());
        //2.    dexElements
        Field dexElementsField=Utils.findField(pathList,"dexElements");
        Object[] dexElements=(Object[])dexElementsField.get(pathList);
        //3.      dexElements   
        Method makeDexElements=Utils.findMethod(pathList,"makePathElements",List.class,File.class,List.class);

        ArrayList suppressedExceptions = new ArrayList();
        Object[] addElements=(Object[])makeDexElements.invoke(pathList,dexFiles,versionDir,suppressedExceptions);

        //    
        Object[] newElements= (Object[])Array.newInstance(dexElements.getClass().getComponentType(),dexElements.length+addElements.length);
        System.arraycopy(dexElements,0,newElements,0,dexElements.length);
        System.arraycopy(addElements,0,newElements,dexElements.length,addElements.length);

        //   DexPathList    element   
        dexElementsField.set(pathList,newElements);
    }

1. sdk\build-tools               dex   jar
dx --dex --output out.dex in.jar
2.    exec   
File aarFile=new File("proxy_core/build/outputs/aar/proxy_core-debug.aar");
        File aarTemp=new File("proxy_tools/temp");
        Zip.unZip(aarFile,aarTemp);
        File classesJar=new File(aarTemp,"classes.jar");
        File classesDex=new File(aarTemp,"classes.dex");
        String absolutePath = classesDex.getAbsolutePath();
        String absolutePath1 = classesJar.getAbsolutePath();
        //dx --dex --output out.dex in.jar
        //dx --dex --output //D:\Downloads\android_space\DexDEApplication\proxy_tools\temp\classes.dex //D:\Downloads\android_space\DexDEApplication\proxy_tools\temp\classes.jar
        Process process=Runtime.getRuntime().exec("cmd /c dx --dex --output "+classesDex.getAbsolutePath()
                                    +" "+classesJar.getAbsolutePath());
        process.waitFor();
        if(process.exitValue()!=0){
            throw new RuntimeException("dex error");
        }

 File apkFile=new File("app/build/outputs/apk/debug/app-debug.apk");
        File apkTemp=new File("app/build/outputs/apk/debug/temp");
        Zip.unZip(apkFile,apkTemp);
        //  dex       
        File[] dexFiles=apkTemp.listFiles(new FilenameFilter() {
            @Override
            public boolean accept(File file, String s) {
                return s.endsWith(".dex");
            }
        });
        //AES   
        AES.init(AES.DEFAULT_PWD);
        for (File dexFile : dexFiles) {
            byte[] bytes = Utils.getBytes(dexFile);
            byte[] encrypt = AES.encrypt(bytes);
            FileOutputStream fos=new FileOutputStream(new File(apkTemp,
                    "secret-"+dexFile.getName()));
            fos.write(encrypt);
            fos.flush();
            fos.close();
            dexFile.delete();
}

 File apkTemp=new File("app/build/outputs/apk/debug/temp");
        File aarTemp=new File("proxy_tools/temp");
        File classesDex=new File(aarTemp,"classes.dex");
        classesDex.renameTo(new File(apkTemp,"classes.dex"));
        File unSignedApk=new File("app/build/outputs/apk/debug/app-unsigned.apk");
        Zip.zip(apkTemp,unSignedApk);