Star Savior Extractor

Desktop app and Python engine for extracting game data from Star Savior (Unity 6 Mono).

Overview

Star Savior uses Unity 6 with encrypted .bundle files and an inner templet encryption layer on game data tables. This toolchain handles:

1. Bundle Decryption -- XOR-decrypt 1,899 encrypted bundles from Data/eb/
2. Templet Decryption -- Decrypt inner .bytes TextAsset files (game data tables) with MD5-based XOR mask + LZ4 decompression
3. Asset Extraction -- Extract textures, sprites, and other assets via UnityPy

Encryption Details

Bundle Encryption

• 16-byte repeating XOR key derived per bundle
• Key derivation: MD5(first_32_chars_of_filename + ".bytes") -> 16-byte mask
• XOR applied to first 102,400 bytes
• Some bundles use a "Type 1" fixed key (0xFFBBCC21 repeating, 128-byte limit)
• Compressed blocks may have an additional PartialBitBlend layer

Templet Encryption (Inner Layer)

• 4-byte magic: 0x2B21DE00 + version_byte
• Version 0/1: LZ4 compressed JSON
• Version 2: MD5-based XOR mask (MD5(filename + ".bytes")) applied to LZ4-framed data, then decompressed
• Raw bytes must be read directly via obj.get_raw_data() -- UnityPy corrupts binary TextAsset data when reading as string

Project Structure

src/                  # React 19 frontend (Tauri v2 app)
  api/                # Desktop API bridge and types
  hooks/              # React hooks for extraction state
src-tauri/            # Rust backend (Tauri commands)
  src/commands/       # Tauri command handlers (decrypt, extract, process)
engine/               # Python extraction engine
  src/
    bundle_decryptor.py    # Bundle XOR decryption + block parsing
    asset_extractor.py     # UnityPy-based asset extraction
    catalog_parser.py      # Unity catalog.json parser
    extractor.py           # Frida-based live extraction
  hooks/                   # Frida JavaScript hooks (22 files)
    main.js                # Primary Mono heap scan hook
    hook_bitblend.js       # PartialBitBlend stream capture
    hook_filename.js       # FileNameMasking/MD5 key capture
    hook_banner_dates.js   # Gacha schedule/banner date extraction
    equip_substats.js      # Equipment substat hook (WIP)
    ...
  decrypt_templets_v2.py   # Standalone templet decryption script
  main.py                  # CLI entry point with all subcommands

Desktop App

Built with Tauri v2 + React 19 + TypeScript.

npm install
npx tauri dev    # dev mode
npx tauri build  # production build

Python Engine CLI

cd engine
pip install -r requirements.txt

# Check game/catalog status
python main.py status

# Decrypt all bundles (1,899 files from Data/eb/)
python main.py decrypt

# Decrypt + extract assets in one pass
python main.py decrypt-extract

# Decrypt templets (game data tables) from decrypted bundles
python decrypt_templets_v2.py

# Search catalog for keys
python main.py catalog --search "icon"

Frida Commands (game must be running)

# Live Mono heap extraction
python main.py extract --process StarSavior.exe

# Scan GC handle types
python main.py scan-types --process StarSavior.exe

# Hook PartialBitBlend stream
python main.py hook-bitblend --process StarSavior.exe

# Hook filename masking / MD5 key derivation
python main.py hook-filename --process StarSavior.exe

# Extract gacha banner dates
python main.py hook-banner-dates --process StarSavior.exe

Extraction Results

• 1,899 / 1,899 bundles decrypted successfully
• 2,156 templet files decrypted (167 MB) -- character stats, skills, equipment, localization (14 languages), etc.
• Textures: UI atlases, skill icons, stat bar images
• Sprites: UI buttons, frames, popup elements

Requirements

• Python 3.10+ with frida, UnityPy, Pillow, lz4, numpy
• Node.js 20+ and Rust toolchain for the desktop app
• Star Savior installed (default: C:\Program Files (x86)\Steam\steamapps\common\StarSavior\)

Notes

• Frida's standard Mono/Il2Cpp APIs are not available with this game's embedded Mono runtime. Only raw memory scanning via Process.enumerateModules() works. The hooks use direct pointer manipulation instead.
• Equipment substat exact values are server-side only and not available in client templet files.
• Some NPC arcana card images (Lisa, Lisette) are missing from extracted textures.