反 逆 向 工 程A n t i - D e c o m p i l e r

黃 思 齊 Suki Huang H O L I E S T A R S T U D I O

VoiceTube – Android Engineer

NUTC – Information Management

Gogolook – Android Intern

Microsoft Student Partner

[ _____________ ] 專業版 去廣告破解下載

[ _____________ ] 無廣告 金錢道具無限破解版下載

從前從前有支 APP 進入大陸地區後

出現了各種變形版本

盜版充斥

Manifest 修改權限抽換廣告

無廣告版本 公開原始碼

Server API 安全性

你的 APK 安全嗎 ?

敏感資料

程式碼廣告 ID

分析平台 ID

Server API 接口驗證碼

基礎保護混淆 (Proguard)

底層 (NDK)

加密服務

基礎保護

基礎保護

Package Name

權限偵錯模式

模擬器

混淆P r o g u a r d

public class MyClass { private boolean isRain=false; private int typhoonLevel=5; private int priceVegetable=10;

private String getAction(){ if(isRain && typhoonLevel>=5){ priceVegetable++; String action="Go white water rafting"; return action; } }}

Before Proguard

After Proguard

public class a { private boolean a=false; private int b=5; private int c=10;

private String a(){ if(a && b>=5){ c++; String d="Go white water rafting"; return d; } }}

Proguard

Class Name

Method

Variables

buildTypes {

release { //minifyEnabled false minifyEnabled true proguardFiles getDefaultProguardFile

('proguard-android.txt'),'proguard-rules.pro' }

}

優 化混 淆壓 縮

P r o g u a r d

C r a s h

try { //May throw exceptions} catch (Exception e) { //Report crash info to ……}

底層(Native Development Kit, NDK)

After Proguard

public class a { private boolean a=false; private int b=5; private int c=10;

private String a(){ if(a && b>=5){ c++; String d="Go white water rafting"; return d; } }}

Android NDK

The Android NDK is a toolset that lets you implement

parts of your app using native-code languages such as C

and C++. For certain types of apps, this can help you

reuse existing code libraries written in those

languages.

public class MyActivity extends Activity {  /**  * Native method implemented in C/C++  */  public native void computeFoo();}

NDKNormal

public class NativeMethod { static { System.loadLibrary("HelloWorld"); } public native static String getkey();}

JNIEXPORT jstring Java_com_test_constants_NativeMethod_getKey(JNIEnv* env,jobject obj) { return env->NewStringUTF("ABCD");}

com.test.constants.NativeMethod.java

HelloWorld.cpp

Ke y S t o r e

if(isKeyStorePassed(context)){ return env->NewStringUTF("ABCD");}else{ return env->NewStringUTF("-----")}

Java_com_test_constants_NativeMthod_getKey

ABCD

ASCII Code

A n d r o i d T a i p e i

65 110 100 114 111 105 100 84 97 105 112 101 105

66 111 101 115 112 106 101 85 98 106 113 102 106

B o e s p j e U b j q f j

Java_com_test_constants_NativeMthod_getKey

com.test.constants.NativeMethod.java

public class NativeMethod { static { System.loadLibrary("HelloWorld"); } public native static String getKey();

}

Java_com_test_constants_NativeMthod_a_____

com.test.constants.NativeMethod.java

public class NativMethod { static { System.loadLibrary("HelloWorld"); } public native static String a(); public static String getKey(){ return a(); }}

Java_com_test_constants_NativeMthod_a_____

Java_com_test_constants_NativeMthod_b_____

Java_com_test_constants_NativeMthod_c_____

Java_com_test_constants_NativeMthod_d_____

Java_com_test_constants_NativeMthod_e____

After Proguard

public class a { private boolean a=false; private int b=5; private int c=10;

private String a(){ if(a && b>=5){ c++; String d=NativeMethod.a(); return d; } }}

加密服務

Core

Apk

Shell

沒 有 絕 對 防 禦

只 有 增 加 破 解 成 本

Thanks for your attention

反 逆 向 工 程