version: "1.0.0" name: kctf-android-jni-mixed-flow description: Solve KCTF Android APKs with JNI bridges, native .so logic, channel splits, and mixed Java/native state machines. Use when the artifact includes classes.dex, lib/*.so, and the check is split across Java input, JNI dispatch, and native code.
KCTF Android JNI Mixed Flow
Workflow
- Identify package, activity, JNI exports, and the native library path.
- Separate Java-side validation from native-side validation.
- Trace the full path:
- Java input
- JNI entry
- native state transforms
- final success string
- Check for channel splits, hex/byte conversion, or fixed-size buffers before solving.
- Verify on the original APK or extracted sample, not on decompiled pseudocode alone.
Use this pattern
classes.dex + lib/*.soJava_com_* JNI exports- even/odd or split-channel transforms
- native anti-debug / state-machine / crypto logic
Reference