阅读本文前，假设读者已经看过Android Studio Xposed模块编写（一) 相关环境已经搭建完成。本文演示案例与上文环境一致，不在赘述。
1、概述
Xposed是非常牛叉的一款hook框架，本人也是刚刚接触，在网上搜索一些资料，发现写的都不是太全面，于是搜集该框架的用法，总结出该文。如有纰漏，还请轻拍，主要内容包括
1、如何Hook静态变量
2、如何Hook构造方法
3、如何Hook复杂参数的方法
4、如何替换函数执行内容
5、如何Hook内部类中的函数
6、如何Hook匿名类的函数
7、如何获取调用对象去调用函数，或者新建新建示例去调用方法
学会这些方法，在结合逆向smail的一些知识，应该可以满足大多数java层的hook了。话不多说，上代码！
2、Hook目标程序源码
HookDemo.java
abstract class Animal{
int anonymoutInt = 500;
public abstract void eatFunc(String value);
}
public class HookDemo {
private String Tag = "HookDemo";
private static int staticInt = 100;
public int publicInt = 200;
private int privateInt = 300;
public HookDemo(){
this("NOHook");
Log.d(Tag, "HookDemo() was called|||");
}
private HookDemo(String str){
Log.d(Tag, "HookDemo(String str) was called|||" + str);
}
public void hookDemoTest(){
Log.d(Tag, "staticInt = " + staticInt);
Log.d(Tag, "PublicInt = " + publicInt);
Log.d(Tag, "privateInt = " + privateInt);
publicFunc("NOHook");
Log.d(Tag, "PublicInt = " + publicInt);
Log.d(Tag, "privateInt = " + privateInt);
privateFunc("NOHook");
staticPrivateFunc("NOHook");
String[][] str = new String[1][2];
Map map = new HashMap<String, String>();
map.put("key", "value");
ArrayList arrayList = new ArrayList();
arrayList.add("listValue");
complexParameterFunc("NOHook", str, map, arrayList);
repleaceFunc();
anonymousInner(new Animal() {
@Override
public void eatFunc(String value) {
Log.d(Tag, "eatFunc(String value) was called|||" + value);
Log.d(Tag, "anonymoutInt = " + anonymoutInt);
}
}, "NOHook");
InnerClass innerClass = new InnerClass();
innerClass.InnerFunc("NOHook");
}
public void publicFunc(String value){
Log.d(Tag, "publicFunc(String value) was called|||" + value);
}
private void privateFunc(String value){
Log.d(Tag, "privateFunc(String value) was called|||" + value);
}
static private void staticPrivateFunc(String value){
Log.d("HookDemo", "staticPrivateFunc(Strin value) was called|||" + value);
}
private void complexParameterFunc(String value, String[][] str, Map<String,String> map, ArrayList arrayList)
{
Log.d("HookDemo", "complexParameter(Strin value) was called|||" + value);
}
private void repleaceFunc(){
Log.d(Tag, "repleaceFunc will be replace|||");
}
public void anonymousInner(Animal dog, String value){
Log.d(Tag, "anonymousInner was called|||" + value);
dog.eatFunc("NOHook");
}
private void hideFunc(String value){
Log.d(Tag, "hideFunc was called|||" + value);
}
class InnerClass{
public int innerPublicInt = 10;
private int innerPrivateInt = 20;
public InnerClass(){
Log.d(Tag, "InnerClass constructed func was called");
}
public void InnerFunc(String value){
Log.d(Tag, "InnerFunc(String value) was called|||" + value);
Log.d(Tag, "innerPublicInt = " + innerPublicInt);
Log.d(Tag, "innerPrivateInt = " + innerPrivateInt);
}
}
}
3、XposedHook程序源码
public class XposedHook implements IXposedHookLoadPackage {
@Override
public void handleLoadPackage(XC_LoadPackage.LoadPackageParam loadPackageParam) throws Throwable {
if (loadPackageParam.packageName.equals("com.example.xposedhooktarget")) {
final Class<?> clazz = XposedHelpers.findClass("com.example.xposedhooktarget.HookDemo", loadPackageParam.classLoader);
//getClassInfo(clazz);
//不需要获取类对象，即可直接修改类中的私有静态变量staticInt
XposedHelpers.setStaticIntField(clazz, "staticInt", 99);
//Hook无参构造函数，啥也不干。。。。
XposedHelpers.findAndHookConstructor(clazz, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
XposedBridge.log("Haha, HookDemo constructed was hooked" );
//大坑，此时对象还没有建立，即不能获取对象，也不能修改非静态变量的值
//XposedHelpers.setIntField(param.thisObject, "publicInt", 199);
//XposedHelpers.setIntField(param.thisObject, "privateInt", 299);
}
});
//Hook有参构造函数，修改参数
XposedHelpers.findAndHookConstructor(clazz, String.class, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
param.args[0] = "Haha, HookDemo(str) are hooked";
}
});
//Hook有参构造函数，修改参数------不能使用XC_MethodReplacement()替换构造函数内容，
//XposedHelpers.findAndHookConstructor(clazz, String.class, new XC_MethodReplacement() {
// @Override
// protected Object replaceHookedMethod(MethodHookParam methodHookParam) throws Throwable {
// Log.d("HookDemo" , "HookDemo(str) was replace");
// }
//});
//Hook公有方法publicFunc，
// 1、修改参数
// 2、修改下publicInt和privateInt的值
// 3、再顺便调用一下隐藏函数hideFunc
//XposedHelpers.findAndHookMethod("com.example.xposedhooktarget.HookDemo", clazz.getClassLoader(), "publicFunc", String.class, new XC_MethodHook()
XposedHelpers.findAndHookMethod(clazz, "publicFunc", String.class, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
param.args[0] = "Haha, publicFunc are hooked";
XposedHelpers.setIntField(param.thisObject, "publicInt", 199);
XposedHelpers.setIntField(param.thisObject, "privateInt", 299);
// 让hook的对象本身去执行流程
Method md = clazz.getDeclaredMethod("hideFunc", String.class);
md.setAccessible(true);
//md.invoke(param.thisObject, "Haha, hideFunc was hooked");
XposedHelpers.callMethod(param.thisObject, "hideFunc", "Haha, hideFunc was hooked");
//实例化对象，然后再调用HideFunc方法
//Constructor constructor = clazz.getConstructor();
//XposedHelpers.callMethod(constructor.newInstance(), "hideFunc", "Haha, hideFunc was hooked");
}
});
//Hook私有方法privateFunc，修改参数
//XposedHelpers.findAndHookMethod("com.example.xposedhooktarget.HookDemo", clazz.getClassLoader(), "privateFunc", String.class, new XC_MethodHook()
XposedHelpers.findAndHookMethod(clazz, "privateFunc", String.class, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
param.args[0] = "Haha, privateFunc are hooked";
}
});
//Hook私有静态方法staticPrivateFunc, 修改参数
XposedHelpers.findAndHookMethod(clazz, "staticPrivateFunc", String.class, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
param.args[0] = "Haha, staticPrivateFunc are hooked";
}
});
//Hook复杂参数函数complexParameterFunc
Class fclass1 = XposedHelpers.findClass("java.util.Map", loadPackageParam.classLoader);
Class fclass2 = XposedHelpers.findClass("java.util.ArrayList", loadPackageParam.classLoader);
XposedHelpers.findAndHookMethod(clazz, "complexParameterFunc", String.class,
"[[Ljava.lang.String;", fclass1, fclass2, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
param.args[0] = "Haha, complexParameterFunc are hooked";
}
});
//Hook私有方法repleaceFunc, 替换打印内容
XposedHelpers.findAndHookMethod(clazz, "repleaceFunc", new XC_MethodReplacement() {
@Override
protected Object replaceHookedMethod(MethodHookParam methodHookParam) throws Throwable {
Log.d("HookDemo", "Haha, repleaceFunc are replaced");
return null;
}
});
//Hook方法, anonymousInner， 参数是抽象类，先加载所需要的类即可
Class animalClazz = loadPackageParam.classLoader.loadClass("com.example.xposedhooktarget.Animal");
XposedHelpers.findAndHookMethod(clazz, "anonymousInner", animalClazz, String.class, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
XposedBridge.log("HookDemo This is test");
param.args[1] = "Haha, anonymousInner are hooked";
}
});
//Hook匿名类的eatFunc方法，修改参数，顺便修改类中的anonymoutInt变量
XposedHelpers.findAndHookMethod("com.example.xposedhooktarget.HookDemo$1", clazz.getClassLoader(),
"eatFunc", String.class, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
param.args[0] = "Haha, eatFunc are hooked";
XposedHelpers.setIntField(param.thisObject, "anonymoutInt", 499);
}
});
//hook内部类的构造方法失败，且会导致hook内部类的InnerFunc方法也失败，原因不明
// XposedHelpers.findAndHookConstructor(clazz1, new XC_MethodHook() {
// @Override
// protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
// XposedBridge.log("Haha, InnerClass constructed was hooked" );
// }
// });
//Hook内部类InnerClass的InnerFunc方法，修改参数，顺便修改类中的innerPublicInt和innerPrivateInt变量
final Class<?> clazz1 = XposedHelpers.findClass("com.example.xposedhooktarget.HookDemo$InnerClass", loadPackageParam.classLoader);
XposedHelpers.findAndHookMethod(clazz1, "InnerFunc", String.class, new XC_MethodHook() {
@Override
protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
param.args[0] = "Haha, InnerFunc was hooked";
XposedHelpers.setIntField(param.thisObject, "innerPublicInt", 9);
XposedHelpers.setIntField(param.thisObject, "innerPrivateInt", 19);
}
});
}
}
private void getClassInfo(Class clazz) {
//getFields()与getDeclaredFields()区别:getFields()只能访问类中声明为公有的字段,私有的字段它无法访问，
//能访问从其它类继承来的公有方法.getDeclaredFields()能访问类中所有的字段,与public,private,protect无关，
//不能访问从其它类继承来的方法
//getMethods()与getDeclaredMethods()区别:getMethods()只能访问类中声明为公有的方法,私有的方法它无法访问,
//能访问从其它类继承来的公有方法.getDeclaredFields()能访问类中所有的字段,与public,private,protect无关,
//不能访问从其它类继承来的方法
//getConstructors()与getDeclaredConstructors()区别:getConstructors()只能访问类中声明为public的构造函数
//getDeclaredConstructors()能访问类中所有的构造函数,与public,private,protect无关
//XposedHelpers.setStaticObjectField(clazz,"sMoney",110);
//Field sMoney = clazz.getDeclaredField("sMoney");
//sMoney.setAccessible(true);
Field[] fs;
Method[] md;
Constructor[] cl;
fs = clazz.getFields();
for (int i = 0; i < fs.length; i++) {
XposedBridge.log("HookDemo getFiled: " + Modifier.toString(fs[i].getModifiers()) + " " +
fs[i].getType().getName() + " " + fs[i].getName());
}
fs = clazz.getDeclaredFields();
for (int i = 0; i < fs.length; i++) {
XposedBridge.log("HookDemo getDeclaredFields: " + Modifier.toString(fs[i].getModifiers()) + " " +
fs[i].getType().getName() + " " + fs[i].getName());
}
md = clazz.getMethods();
for (int i = 0; i < md.length; i++) {
Class<?> returnType = md[i].getReturnType();
XposedBridge.log("HookDemo getMethods: " + Modifier.toString(md[i].getModifiers()) + " " +
returnType.getName() + " " + md[i].getName());
//获取参数
//Class<?> para[] = md[i].getParameterTypes();
//for (int j = 0; j < para.length; ++j) {
//System.out.print(para[j].getName() + " " + "arg" + j);
//if (j < para.length - 1) {
// System.out.print(",");
//}
//}
}
md = clazz.getDeclaredMethods();
for (int i = 0; i < md.length; i++) {
Class<?> returnType = md[i].getReturnType();
XposedBridge.log("HookDemo getDeclaredMethods: " + Modifier.toString(md[i].getModifiers()) + " " +
returnType.getName() + " " + md[i].getName());
}
cl = clazz.getConstructors();
for (int i = 0; i < cl.length; i++) {
XposedBridge.log("HookDemo getConstructors: " + Modifier.toString(cl[i].getModifiers()) + " " +
md[i].getName());
}
cl = clazz.getDeclaredConstructors();
for (int i = 0; i < cl.length; i++) {
XposedBridge.log("HookDemo getDeclaredConstructors: " + Modifier.toString(cl[i].getModifiers()) + " " +
md[i].getName());
}
}
}
4、Hook运行结果
5、源码地址
Hook目标程序源码https://github.com/Gordon0918/XposedHookTarget
Hook程序源码https://github.com/Gordon0918/XposedHook