KCTF Android JNI Mixed Flow

SkillWeb & browsing

Guides your agent through solving Android crackme challenges that split validation logic between Java code and native libraries.

Available today. Use it from your connected AI after setup.

Add ahel to your AI once: Claude, ChatGPT, Cursor, Claude Code or Codex. Then ask it to use this.

Then ask your AI: use the KCTF Android JNI Mixed Flow skill

About this skill

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.

What this skill tells your AI

The instructions your AI receives, as published by manyuegong33/r0crawl_skills in skills/kctf-android-jni-mixed-flow/SKILL.md and read by ahel’s review.

Workflow

  1. Identify package, activity, JNI exports, and the native library path.
  2. Separate Java-side validation from native-side validation.
  3. Trace the full path:
    • Java input
    • JNI entry
    • native state transforms
    • final success string
  4. Check for channel splits, hex/byte conversion, or fixed-size buffers before solving.
  5. Verify on the original APK or extracted sample, not on decompiled pseudocode alone.

Use this pattern

  • classes.dex + lib/*.so
  • Java_com_* JNI exports
  • even/odd or split-channel transforms
  • native anti-debug / state-machine / crypto logic

Reference

  • references/pattern.md

Signals

GitHub stars
285
Forks
100
Last commit
Sep 2026
Advanced
Catalog kind
skill
Key
kctf-android-jni-mixed-flow
Source
github.com/manyuegong33/r0crawl_skills