Frida 打印 class 中的所有变量

Question

嗨我的教授问你如何在 class 中打印变量的内容他为我们提供了一个 apk，可以用 frida 启动和分析：

package com.test_uni_apk.lib.proftest;


 public class ProfApi{


  public static class StateReady
  extends ProfApi.CallState
  {


  public CallStateReady() {}

  public CallStateReady(ProfApi.CallProc paramCallProc, 
    ProfApi.CallConnection[] paramArrayOfCallConnection, String 
     paramString, byte[] paramArrayOfByte, String[] paramArrayOfString)
   {

  this.printthis = paramArrayOfCallConnection;

  }


 }


}

我读到你可以使用 frida 挂钩 class 但我不明白如何打印 printthis 的值。

Answer 1

我假设 CallStateReady 是 com.test_uni_apk.lib.proftest.ProfApi 的内部 class 并且您想挂钩 c'tor 并打印第二个参数 #PleaseSubmitElegantCode

function printParamArrayOfCallConnection() {
    var ArrayList = Java.use("java.util.ArrayList");
    var CallConnection = Java.use("com.test_uni_apk.lib.proftest.ProfApi$CallConnection");
    Java.use("com.test_uni_apk.lib.proftest.ProfApi$CallStateReady") // dollar sign for inner class
        .$init // init represent the constructor
        // list of arguments are passed in byte code style, [B represents byte array
        // when you try to hook Frida will provide an informative error with all the possible arguments for overloading
        // copy & paste the right one which will look like this:
        .overload("Lcom..ProfApi.CallProc;", "Lcom...ProfApi.CallConnection;", "java.lang.String", "[B", "Ljava.lang.String;")
        .implementation = function(paramCallProc, paramArrayOfCallConnection, paramString, paramArrayOfByte, paramArrayOfString) {
            // first we cast to list
            var list = Java.cast(paramArrayOfCallConnection, ArrayList);
            // iterating the list
            for (var i = 0, l = list.size(); i < l; i++) {
                // casting each element to the object we created earlier
                var currentElement = Java.cast(list.get(i), CallConnection);
                // printing to terminal
                console.log(i, currentElement);
            }
            // executing original c'tor 
            this.$init(paramCallProc, paramArrayOfCallConnection, paramString, paramArrayOfByte, paramArrayOfString);
        }
}
Java.perform(printParamArrayOfCallConnection);

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