Library Call Solution

Solution

1. Follow the challenge set up guide.
2. Download the apk and library folder:
   adb pull /data/app/ruhrpott.owasp.com.vuln_app_1 .
3. Retrieve function name and namespace:
   Command: strings ./lib/x86/liblibcall.so | grep -i java
   Output: Java_ruhrpott_owasp_com_vuln_1app_11__challenges_Library_stringFromJNI
4. Create a new Android Studio project with the same namespace as the application. (ruhrpott.owasp.com.vuln_app_1)
5. Create the same class and function name in the folder challenges.
   

• Class: LibraryCall.java
• Function: stringFromJNI()

6. Load library: System.loadLibrary("libcall")
7. Place the downloaded library under /main/jniLibs/ge/.

The a working Android Studio project can be found here.

Links

• https://developer.android.com/ndk/samples/sample_hellojni.html