Question

嗨我的教授问您如何在一个班级中打印变量的内容他为我们提供了一个可以通过frida启动和分析的apk：

price

我读到frida可以钩住一个类，但我不知道如何打印printthis的值。

Answer 1

我将假设CallStateReady是com.test_uni_apk.lib.proftest.ProfApi的内部类，并且您想挂接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);

Frida打印类中的所有变量

1 个答案: