Antigravity Agent
f8b21af4be
10_Wiki/Topics 대규모 정리: - 오류 캡처/미완성 stub 문서 227개 제거 - 교차폴더 중복 43클러스터 병합 (63파일 → redirect) - 링크명 정규화: 깨진 링크 수정·redirect 직결·개념 매핑 ~2,400건 - 카테고리 MOC 6개 신규 생성 - Graph 섹션 미해결 related-keyword 링크 10,058건 제거 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
158 lines
4.5 KiB
Markdown
158 lines
4.5 KiB
Markdown
---
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id: wiki-2026-0508-code-obfuscation
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title: Code Obfuscation
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category: 10_Wiki/Topics
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status: verified
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canonical_id: self
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aliases: [Obfuscation, Anti-Reverse Engineering]
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duplicate_of: none
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source_trust_level: A
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confidence_score: 0.9
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verification_status: applied
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tags: [security, reverse-engineering, drm, javascript]
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raw_sources: []
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last_reinforced: 2026-05-10
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github_commit: pending
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tech_stack:
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language: JavaScript/C++
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framework: obfuscator.io/LLVM-Obfuscator
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---
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# Code Obfuscation
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## 매 한 줄
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> **"매 reverse-engineering cost 의 raise — semantic 보존하면서 readability 파괴"**. Crypto 처럼 secrecy 가 아닌 cost-shifting — determined attacker 는 매 결국 풀 수 있음. 매 modern usage: anti-piracy, anti-cheating, license validation, 매 LLM-based deobfuscation 의 등장으로 의미 retreat.
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## 매 핵심
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### 매 layer
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- **Lexical**: rename identifier (`x_a1b2c3`).
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- **Control flow**: opaque predicate, control-flow flattening.
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- **Data**: string encryption, constant unfolding.
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- **Anti-analysis**: anti-debug, VM detection, integrity check.
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- **Virtualization**: custom VM bytecode (VMProtect, Themida).
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### 매 trade-off
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- Performance: 2-10× slowdown (virtualization 시).
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- Size: 2-5× binary bloat.
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- Stability: false positive 가능 (anti-debug).
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- Security: 매 cost-raise 만 — break 시간을 hours → weeks 로.
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### 매 응용
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1. JavaScript bundle (anti-scraping).
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2. Mobile app DRM, license check.
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3. Game anti-cheat (e.g., VAC, EAC).
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4. Malware (defensive obfuscation).
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## 💻 패턴
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### String encryption
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```javascript
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// Before
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const KEY = "secret-api-key";
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// After
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const _0xa1b2 = ['c2VjcmV0', 'LWFwaQ==', 'LWtleQ=='];
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const _0xc3d4 = (i) => atob(_0xa1b2[i]);
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const KEY = _0xc3d4(0) + _0xc3d4(1) + _0xc3d4(2);
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```
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### Control-flow flattening
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```c
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// Before: linear flow
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void f() { a(); b(); c(); }
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// After: dispatcher loop
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void f_obf() {
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int state = 0;
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while (state != -1) {
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switch (state) {
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case 0: a(); state = 7; break;
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case 7: b(); state = 3; break;
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case 3: c(); state = -1; break;
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}
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}
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}
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```
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### Opaque predicate
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```cpp
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// Always true at runtime, hard to determine statically
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auto opaque = [](int x) { return (x*x*x - x) % 3 == 0; }; // always true for any int
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if (opaque(rand())) real_logic();
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else fake_branch(); // dead but appears live to disassembler
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```
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### Identifier mangling (terser)
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```javascript
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// terser config
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{
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mangle: {
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toplevel: true,
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properties: { regex: /^_/ }
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},
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compress: { passes: 3, dead_code: true }
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}
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```
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### Anti-debug (browser)
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```javascript
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setInterval(() => {
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const t = performance.now();
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debugger; // pauses if devtools open
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if (performance.now() - t > 100) {
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// devtools detected
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location.href = 'about:blank';
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}
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}, 1000);
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```
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### LLVM IR pass (obfuscator-llvm style)
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```cpp
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struct StringObfPass : PassInfoMixin<StringObfPass> {
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PreservedAnalyses run(Module &M, ModuleAnalysisManager&) {
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for (auto &GV : M.globals()) {
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if (auto *CDA = dyn_cast<ConstantDataArray>(GV.getInitializer())) {
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if (CDA->isString()) xor_encrypt(GV);
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}
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}
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return PreservedAnalyses::none();
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}
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};
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```
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## 매 결정 기준
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| 상황 | Approach |
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| Web bundle anti-scraping | terser + javascript-obfuscator |
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| Native binary (commercial) | VMProtect / Themida |
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| Open-source w/ embedded secret | DON'T — use server-side proxy |
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| Game anti-cheat | Kernel driver + virtualization |
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| Mobile DRM | Hardware-backed (TEE, SEP) — obfuscation 보조 |
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**기본값**: Don't obfuscate — secrets belong server-side. Necessary 시 매 layered defense.
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## 🔗 Graph
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- 응용: [[Malware Analysis]]
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## 🤖 LLM 활용
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**언제**: Defense-in-depth context, malware analysis 학습, anti-tamper design.
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**언제 X**: Hiding actual secrets — broken by definition. 매 server-side 가 답.
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## ❌ 안티패턴
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- **Security through obscurity (alone)**: 매 always falls.
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- **Embedding API key in client**: obfuscation 으로도 매 보호 불가.
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- **Custom crypto**: roll-your-own → obfuscation 보다 매 weaker.
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- **Performance ignored**: 10× slowdown 으로 UX 망침.
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- **No update path**: 매 break 되면 매 fresh release 필요 — automation 필수.
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## 🧪 검증 / 중복
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- Verified (Collberg taxonomy, obfuscator-llvm, javascript-obfuscator).
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- 신뢰도 A.
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## 🕓 Changelog
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| 날짜 | 변경 |
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| 2026-05-08 | Phase 1 |
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| 2026-05-10 | Manual cleanup — obfuscation taxonomy + JS/LLVM patterns |
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