javascript - Frida - 调用特定方法重载

Question

我正在探索一个 Android 程序，该程序具有多个具有相同名称和参数的方法。

我需要调用特定的方法重载。Java 代码如下

package a;
public class d
{
     public int a() {
        return 10;
    }

    public long a() {
        return 20;
    }
    public long b() {
        long ret = a();
        return ret + 1;
    }
}

我需要替换 b() 的实现并调用 (int)a() 而不是 (long)a()。请帮我修复我的 frida js 代码。

Java.perform(function () {
  Var Class_A_D = java.Use("a.d");
  Class_A_D.b.implementation = function(){
    var ret = this.(a); // need to call int implementation
    return ret;
 }
}

Answer 1

我用 Java.reflect 找到了答案

Java.perform(function () {
    var Java_lang_Object = Java.use('java.lang.Object');
    var Java_lang_String = Java.use('java.lang.String');
//This function get method reference by reflect
        function dynamic_search_method(io_object, iv_name, iv_ret_type, it_par){ 
          var lt_methods = io_object.getMethods()  ;
          var lv_found;
          for(var  lv_i=0;lv_i < lt_methods.length;lv_i++){
             if(lt_methods[lv_i].getName().toString()  == iv_name && lt_methods[lv_i].getGenericReturnType().toString() == iv_ret_type){
                var lt_par_type = lt_methods[lv_i].getParameterTypes();
                if(lt_par_type.length == it_par.length){
                  lv_found = true; 
                  for(var  lv_j=0;lv_j < lt_par_type.length && lv_found == true;lv_j++){
                    if(lt_par_type[lv_j].getName().toString() != it_par[lv_j]) lv_found = false  ; 
                  }                   
                  if(lv_found == true) return lt_methods[lv_i];
                }
             }
          }
         return null;
        }
//This function call method dynamically 
        function dynamic_invoke(io_object,io_method, it_par){
          if(io_object===null || io_method ===null ) return null;
          try{
            var lo_cast_obj = Java.cast( io_object ,Java_lang_Object);
          }catch(e){
            return null;
          }
          var lt_par = Java.array('java.lang.Object',it_par);
          return io_method.invoke(lo_cast_obj,lt_par);
        }
//example of use
  Var Class_A_D = java.Use("a.d");


  Class_A_D.b.implementation = function(){
// call method "a" of instance, with "long" return and without parameter
var lo_meth = dynamic_search_method(this.getClass(),"a","long",[]);
var lv_var= dynamic_invoke(this,lo_meth,[]);

// call method "c" of instance, with "android.content.Context" return and with 2 parameters
lo_meth = dynamic_search_method(this.getClass(),"a","class android.content.Context",['java.lang.String','java.lang.String']);
var lv_var= dynamic_invoke(this,lo_meth,[Java_lang_String.$new("Test"),Java_lang_String.$new("String")]);
// call static method
var lo_meth = dynamic_search_method(Class_A_D.class,"d","class java.lang.String",[]);
var lv_var= dynamic_invoke(Class_A_D.class,lo_meth,[]);    
};

)};