📋 Repository Overview

PckKeyChanger is a C# console application designed to change encryption keys in PCK (Perfect World Archive) files. These are archive files used by Perfect World game engine (Angelica Engine).

Key Information:

• Language: C#
• Created: June 26, 2024
• Last Updated: October 13, 2025
• Stars: 3 | Forks: 6
• Purpose: Simple software for changing encryption keys in . pck archive files

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🏗️ Architecture & Structure

Main Components:

1. Program.cs (Entry Point)

• Interactive console application
• Prompts user for:
  • Old encryption keys (KEY_1 and KEY_2) - defaults to Perfect World keys
  • Folder path containing .pck files
  • New encryption keys
  • Compression level (1-9)
• Processes multiple .pck files in parallel using Parallel.ForEach
• Real-time progress tracking with console cursor positioning
• Default keys: -1466731422 and -240896429

2. Core/ArchiveEngine/ (Archive Management)

ArchiveManager.cs - Main archive handler:

• Supports two PCK formats: V2 and V3
• Key methods:
  • ReadFileTable() - Reads file entries from archive
  • ChangeKeys() - Changes encryption keys (creates temporary .defrag file)
  • SaveFileTableChangedKeys() - Saves file table with new keys
  • GetFile() - Extracts individual files
  • Defrag() - Optimizes archive structure

ArchiveStream.cs - Low-level file I/O:

• Handles multi-part archives (. pck, .pkx, .pkx1)
• Maximum sizes:
  • PCK: 2,147,483,392 bytes (~2GB)
  • PKX: 4,294,966,784 bytes (~4GB)
• Buffer size: 16MB for performance
• Supports reading/writing across multiple files seamlessly

ArchiveKey.cs - Encryption key container:

- KEY_1, KEY_2: Main encryption keys
- ASIG_1, ASIG_2: Archive signatures
- FSIG_1, FSIG_2: File signatures

ArchiveEntryV2.cs / ArchiveEntryV3.cs - File entry structures:

• Path (260 bytes, GBK encoding)
• Offset (file location in archive)
• Size (uncompressed size)
• CSize (compressed size)

3. Core/ (Utilities)

Zlib.cs - Compression handler:

• Uses zlib library for compression/decompression
• Adaptive compression (only compresses if result is smaller)

Events.cs - Event delegates:

• Progress tracking
• Data loading notifications

4. Interfaces/

IArchiveEntry.cs - Entry abstraction IArchiveManager.cs - Manager contract

5. Helper Classes

StaticConverter.cs - String/encoding utilities:

• GBK encoding conversion (Chinese character set)
• String manipulation helpers

Utils.cs - General utilities:

• Random string generation
• File validation

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🔑 How Key Changing Works

1. Detect Archive Version: Reads version number from last 4 bytes
2. Read File Table:
   • Decrypts file table using old keys
   • XOR operations with KEY_1 and KEY_2
3. Extract All Files:
   • Decompresses each file
   • Stores in memory
4. Recompress with New Settings:
   • Uses specified compression level
   • Writes to temporary .defrag file
5. Save with New Keys:
   • Encrypts file table with new keys
   • XOR operations with new KEY_1 and KEY_2
6. Replace Original: Deletes old file, renames temp file

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🔐 Perfect World Archive Format

V2 Structure:

[Header:  FSIG_1 + Size + FSIG_2]
[Compressed Files Data]
[File Table (encrypted with KEY_1/KEY_2)]
[Footer: ASIG_1 + Version + FileTableOffset (XOR KEY_1) + Signature + ASIG_2 + FileCount]

V3 Structure:

Similar to V2 but uses 64-bit offsets instead of 32-bit

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💡 Key Features

✅ Parallel Processing - Handles multiple PCK files simultaneously
✅ Multi-part Archives - Supports .pck + .pkx + .pkx1 files
✅ Progress Tracking - Real-time console updates for each file
✅ Compression Control - User-defined compression levels (1-9)
✅ Default Keys - Pre-configured Perfect World encryption keys
✅ Error Handling - Try-catch blocks with detailed error messages
✅ Memory Efficient - 16MB buffered streams

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🎯 Use Cases

• Game Modding: Re-encrypt game archives with custom keys
• Security: Change default Perfect World encryption
• Archive Management: Recompress with different compression levels
• Data Protection: Prevent unauthorized access to game assets

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📦 Dependencies

• System.IO. Compression - For compression operations
• zlib library (via packages.config) - Core compression engine
• . NET Framework - Standard C# libraries

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This is a specialized tool for Perfect World game engine archive manipulation, focusing on encryption key modification while preserving archive integrity and file compression.