【Android 逆向】【攻防世界】app1

1. apk安装到手机， 老套路了

2. jadx打开

        this.btn.setOnClickListener(new View.OnClickListener() { // from class: com.example.yaphetshan.tencentgreat.MainActivity.1
            @Override // android.view.View.OnClickListener
            public void onClick(View v) {
                try {
                    String inputString = MainActivity.this.text.getText().toString();
                    PackageInfo pinfo = MainActivity.this.getPackageManager().getPackageInfo(BuildConfig.APPLICATION_ID, 16384);
                    String versionCode = pinfo.versionName;
                    int versionName = pinfo.versionCode;
                    for (int i = 0; i < inputString.length() && i < versionCode.length(); i++) {
                        if (inputString.charAt(i) != (versionCode.charAt(i) ^ versionName)) {
                            Toast.makeText(MainActivity.this, "再接再厉，加油~", 1).show();
                            return;
                        }
                    }
                    if (inputString.length() == versionCode.length()) {
                        Toast.makeText(MainActivity.this, "恭喜开启闯关之门！", 1).show();
                        return;
                    }
                } catch (PackageManager.NameNotFoundException e) {
                }
                Toast.makeText(MainActivity.this, "年轻人不要耍小聪明噢", 1).show();
            }
        });
    }

这里要获取versionName 和versionCode，直接取AndroidManifest.xml里面找

android:versionCode="15" android:versionName="X<cP[?PHNB<P?aj"

这里要稍微转化一下,写出以下代码

version_code = 15
version_name = "X<cP[?PHNB<P?aj"
result = ""
for c in version_name:
	t_cc = ord(c)
	tt = t_cc^version_code
	print(tt)
	result += chr(tt)
	
print(result)

# 日志
W3l_T0_GAM3_0ne

成功得到flag