--- type: toolset title: Bezetacil Toolset — Electron Runtime Introspection description: Pipeline ASAR, deobfuscation, harness runtime, debugger spy, CDP extraction tags: [claude-desktop, electron, asar, reverse-engineering, harness, toolset] timestamp: 2026-06-24 --- # Bezetacil Toolset — Electron Runtime Introspection Toolset for reverse engineering, patching, and runtime introspection of Electron apps (developed for Claude Desktop). ## Overview ``` ┌─────────────────────────────────────────────────────────┐ │ 1. ASAR Pipeline │ Extract → Patch → Repack → Sign │ │ 2. Deobfuscation │ webcrack → deloom → analysis │ │ 3. Bezetacil Harness │ Runtime injection + hot reload │ │ 4. Debugger Spy │ Network capture + WebSocket │ │ 5. CDP Tools │ Python PEP 723 scripts │ │ 6. Bridge Server │ Bidirectional TCP Python ↔ Node │ └─────────────────────────────────────────────────────────┘ ``` --- ## 1. ASAR Pipeline ### Tools ```bash # Install npm install -g @electron/asar deloom webcrack # Binary locations ~/.hermes/node/bin/asar ~/.hermes/node/bin/deloom ~/.hermes/node/bin/webcrack ``` ### Complete Pipeline ```bash # 1. Backup cp /Applications/Claude.app/Contents/Resources/app.asar /tmp/app.asar.backup # 2. Extract (with symlink to unpacked) ln -sf /Applications/Claude.app/Contents/Resources/app.asar.unpacked /tmp/app.asar.backup.unpacked asar extract /tmp/app.asar.backup /tmp/extracted/ # 3. Patch (Python) python3 -c " with open('/tmp/extracted/.vite/build/index.js') as f: content = f.read() content = content.replace('old', 'new') with open('/tmp/extracted/.vite/build/index.js', 'w') as f: f.write(content) " # 4. Repack (Node.js API — preserves native binaries) cat > /tmp/build.mjs << 'EOF' import { createPackageWithOptions, getRawHeader } from '@electron/asar/lib/asar.js'; import { createHash } from 'crypto'; const src = '/tmp/extracted', dest = '/tmp/app.asar.patched'; await createPackageWithOptions(src, dest, { unpack: '{*.{node,dylib},spawn-helper}' }); const hash = createHash('SHA256').update(getRawHeader(dest).headerString).digest('hex'); console.log('Hash:', hash); EOF node /tmp/build.mjs # 5. Update Info.plist (9 files!) with header hash python3 -c " import plistlib, os HASH = '...' for p in [list of 9 plists]: with open(p,'rb') as f: pl = plistlib.load(f) pl['ElectronAsarIntegrity'] = {'Resources/app.asar': {'algorithm': 'SHA256', 'hash': HASH}} with open(p,'wb') as f: plistlib.dump(pl, f) " # 6. Deploy + Sign cp /tmp/app.asar.patched /Applications/Claude.app/Contents/Resources/app.asar cp -r /tmp/app.asar.patched.unpacked/* /Applications/Claude.app/Contents/Resources/app.asar.unpacked/ sudo codesign --remove-signature /Applications/Claude.app sudo codesign -s - /Applications/Claude.app --deep --force --entitlements /tmp/entitlements.plist ``` ### Lessons Learned - **`--unpack-dir` CLI only accepts 1 value** → use glob `{...}` or Node.js API - **9 copies of `ElectronAsarIntegrity`** spread across Info.plist files - **Hash is SHA256 of `headerString`** (JSON), not the entire file - **`--unpack` CLI is buggy for `.node`** → use API `createPackageWithOptions({unpack})` - **Native binaries** (`.node`, `.dylib`, `spawn-helper`) must stay in `unpacked/` - **Code signing**: remove original signature, re-sign ad-hoc with entitlements - **Minimum entitlements**: `com.apple.security.virtualization`, `com.apple.security.device.audio-input`, `com.apple.security.cs.allow-jit` ### Applied Patches (V17c final) | # | Patch | Purpose | |---|-------|-----------| | 1 | `function Uy(A){return false}` | 1p mode — claude.ai voice UI | | 2 | `voice:{buildGate:()=>!0}` | Enable voice feature | | 3 | `if(false)return{...entitlement_missing...}` | Bypass entitlements verification | | 4 | Audio proxy handler in array `C` | Proxy `/v1/audio/*` → gateway | | 5 | `Sqi="localhost:8443"` | Redirect CSP to Caddy (not effective) | | 6 | `require("../../harness-bootstrap")` | Inject harness at boot | --- ## 2. Deobfuscation ### Pipeline ```bash # Deminify + unpack webpack bundle node ~/.hermes/node/bin/webcrack index.js -o /tmp/demified/ # Result: 19MB deobfuscated.js + extracted modules ls /tmp/demified/ # 333.js 486.js 515.js 747.js 823.js 949.js bundle.json deobfuscated.js ``` ### Key Code Discoveries | Symbol | Meaning | Line | |---------|-------------|-------| | `Uy()` | `deploymentModeIs3p` — returns `true` in 3p | 150368 | | `_cr` | 1p deployment mode class | 216220 | | `nk` | `app://localhost` — URL in 3p | 149817 | | `Cmn()` | Registers protocol handler `app://` | 482078 | | `k3A()` | Blocked paths checker | 481540 | | `qpn` | List of blocked paths in 3p | 481538 | | `Emn()` | API stub handler (array `C`) | 481925 | | `Sqi` | `a-api.anthropic.com` (CSP) | 144596 | | `jr.quickAccess.dictation` | Swift bridge dictation | 318974 | | `fKr()` | Initializes Swift bridge | 319000 | --- ## 3. Bezetacil Harness ### Location ``` ~/.bezetacil/ └── scripts/ └── 001-debugger-spy.js ← auto-loaded at boot ``` ### Harness Bootstrap (injected into `index.js`) ```javascript require("../../harness-bootstrap"); ``` Loads automatically when the app starts. The harness: 1. Reads `~/.bezetacil/scripts/*.js` in alphabetical order 2. Executes each script via `eval()` in the main process context 3. **Hot reload**: `fs.watch()` on directory — editing file = automatic reload 4. Exposes global API: `__HARNESS__.eval()`, `__HARNESS__.log()`, `__HARNESS__.reload()` ### Harness API ```javascript // Execute code in main process __HARNESS__.eval("require('electron').BrowserWindow.getAllWindows().length") // Manual hot reload __HARNESS__.reload() // Status __HARNESS__.status() // → { log: '/tmp/claude-harness.log', scriptsDir: '...', pid: 89917 } ``` ### Development Cycle ``` 1. Edit ~/.bezetacil/scripts/001-my-script.js 2. Save 3. ~3s later: automatic hot reload 4. Check /tmp/claude-harness.log for logs ``` **Zero repacks!** Only need to rebuild if changing the bootstrap itself. ### Naming Convention and Hot Reload **CRITICAL RULE:** Bezetacil scripts must NEVER be versioned with incremental numeric suffixes (e.g., `v001-script.js`, `v002-script.js`, `007-capture.js`). **Why:** The harness loads ALL `*.js` from the directory in alphabetical order. Each hot reload **adds** new handlers via `eval()` without removing previous ones. Versioning with incremental names causes multiple versions of the same script to coexist in memory, each registering their own event listeners — causing handler duplication, race conditions, and files generated with incorrect names. **Correct format:** Use fixed descriptive names. ``` ✅ 001-debugger-spy.js ← fixed name, rewritten when updated ✅ capture-tts-audio.js ← fixed descriptive name ✅ supports1m-autodiscovery.js ← fixed descriptive name ❌ 001-script.js, 002-script.js, 003-script.js ← NEVER do this ❌ v1-spy.js, v2-spy.js ← NEVER do this ❌ 007-capture-tts-audio.js ← NEVER do this ``` **Guard pattern:** Every script must start with a guard to prevent multiple instances after hot reload: ```javascript (function() { // Guard: prevents multiple instances after hot reload if (globalThis.__MY_SCRIPT_LOADED__) return; globalThis.__MY_SCRIPT_LOADED__ = true; // ... script ... })(); ``` **Additional conventions:** - `.js` — active script, loaded at boot - `.js.disabled` — disabled script (ignored by harness) - `.js.inject_first` — injected BEFORE normal scripts (hooks that need to be in place before initialization) - `.js.inject_last` — injected AFTER normal scripts (observers, spy, loggers) **Lifecycle:** ``` 1. Edit ~/.bezetacil/scripts/my-script.js ← always the SAME name 2. Save 3. ~3s later: automatic hot reload 4. Check /tmp/claude-harness.log for logs 5. Restart app if needed to clear old handlers from memory ``` --- ## 4. Debugger Spy ### Script: `001-debugger-spy.js` Uses `webContents.debugger` + `Fetch.enable` + `Network.enable` to capture: - **Fetch/XHR**: URL, method, headers, postData, responseBody - **WebSocket**: frames sent and received (full payload) - **Network**: all requests with URL and method ### Output - `/tmp/voice-captures.json` — array of captures with timestamp - `/tmp/claude-harness.log` — debug logs `[SPY]` ### Capture Example ```json { "ts": "2026-06-23T13:56:35.268Z", "type": "ws", "method": "Network.webSocketFrameReceived", "payload": "{\"type\": \"TranscriptText\", \"data\": \"Houston, we may have a problem.\"}" } ``` ### WebContents covered - `BrowserWindow.getAllWindows()` → main webContents - `webContents.getAllWebContents()` → ALL webContents (including WebContentsView) - `BrowserWindow.getBrowserViews()` → child views --- ## 5. CDP Tools ### Python Scripts (PEP 723 — `uv run`) Location: `/tmp/cdp-*.py` | Script | Function | |--------|--------| | `cdp-eval.py` | Execute JS in main process via CDP | | `cdp-harness.py` | Use harness API via CDP | | `cdp-fetch.py` | Load scripts from file server | | `cdp-load-scripts.py` | Orchestrate injection | ### Usage Pattern ```bash # Connect to CDP (must be active in UI) curl -s http://localhost:9229/json | jq '.[0].webSocketDebuggerUrl' # Execute via harness uv run /tmp/cdp-eval.py ``` ### File Server ```bash cd /tmp/scripts && python3 -m http.server 8765 ``` Allows loading scripts from within Electron without string escaping. --- ## 6. Bridge Server (TCP) ### Concept Bidirectional TCP connection between Python and the Electron main process for real-time commands. ### Files - `/tmp/scripts/bridge-server-v2.py` — async Python server (port 9876) - `/tmp/scripts/harness-bridge.js` — TCP client in Electron ### How It Works ``` Python (bridge-server) ←→ TCP :9876 ←→ Electron (harness-bridge) │ ├─ command: {"id":1, "code":"1+1"} └─ response: {"id":1, "result":"2"} ``` --- ## 7. Entitlements File: `/tmp/entitlements.plist` ```xml com.apple.security.cs.allow-jit com.apple.security.virtualization com.apple.security.device.audio-input com.apple.security.device.camera com.apple.security.device.bluetooth com.apple.security.device.usb com.apple.security.device.print com.apple.security.personal-information.location com.apple.security.personal-information.photos-library ``` Extracted from the original DMG at `/Users/alefita/Downloads/Claude.dmg`. --- ## 8. ASAR Versions | Version | Patches | Status | |--------|---------|--------| | V0 | Original (backup) | Clean base | | V8 | Uy=false, voice gate, entitlement, audio proxy | 3p mode, no voice UI | | V9 | V8 + Uy=false | **Stable** — 1p mode, voice works | | V15 | V9 + harness v1 | Initial harness | | V16 | V15 + Sqi localhost | Redirect attempt (not effective) | | **V17c** | V16 + harness v3 (bezetacil) | **Current** — hot reload, debugger spy | --- ## 9. Scripts Quick Reference ```bash # Full rebuild cd /tmp/claude-v17 && node /tmp/deploy-v17c.mjs # Hot reload — just edit vim ~/.bezetacil/scripts/001-debugger-spy.js # View logs tail -f /tmp/claude-harness.log # View captures cat /tmp/voice-captures.json | python3 -m json.tool | head -50 # Re-sign (after rebuild) sudo codesign --remove-signature /Applications/Claude.app sudo codesign -s - /Applications/Claude.app --deep --force --entitlements /tmp/entitlements.plist ```