# Classic WoW Patcher
A World of Warcraft client patcher written in Rust that lets you run the
WoW client on your own computer and connect to a personal server at home.
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[](https://www.rust-lang.org)
[](LICENSE-APACHE)
[](LICENSE-MIT)
## Overview
Part of the [WoW Emulation project](https://github.com/wowemulation-dev).
The patcher modifies WoW executables by redirecting the login portal,
replacing cryptographic keys, and injecting a custom certificate bundle
to enable connecting to a server you control. You must own the client and
expansions you want to play.
## How It Works
The patcher modifies your WoW executable to redirect it away from Blizzard's
infrastructure and toward your own server. It achieves this by updating three
main components:
1. **Login Redirection** - Replaces the internal address `.actual.battle.net`
with `.localhost`. This tells the game client to look for your login portal on
your local network instead of over the internet.
2. **Identity Verification (RSA Modulus)** - The game uses a 256-byte RSA key
to verify that its \"Certificate Bundle\" is authentic. We replace this standard
Blizzard key with a custom one. This allows the client to trust the security
certificates you provide for your private server.
3. **Compatibility Patches** - For older clients (like those from the 1.13.2
era), we also rewrite the URL used to download these certificates at startup,
ensuring they point to your resources.
The patcher automatically detects which version of the game client you are
running and applies only the necessary patches for that specific build.
## Supported Client Builds
The patcher supports the following WoW Classic client lines:
| Client line | Recreates | Status |
| --------------------- | ---------------------------- | -------- |
| 1.13.x (2019 to 2021) | Vanilla, 2005 (v1.12) | Verified |
| 1.14.x (2021 to 2023) | Vanilla, 2005 (v1.12) | Verified |
| 2.5.x through 2.5.4 | The Burning Crusade, 2007 | Verified |
| 3.4.x through 3.4.4 | Wrath of the Lich King, 2008 | Verified |
| 4.4.x through 4.4.2 | Cataclysm, 2010 | Verified |
Build numbers are the values reported by the client at its login screen and
catalogued at [warcraft.wiki.gg][public-builds].
## Features
- No in-client memory modifications (patches files on disk)
- Supports Windows, macOS, and Linux
- Dry-run mode for previewing changes
- Automatic WoW executable detection on macOS
## Installation
### From Source
```bash
# Clone the repository
git clone https://github.com/wowemulation-dev/wow-patcher
cd wow-patcher
# Build the project
cargo build --release
# The binary will be available at target/release/wow-patcher
```
## Usage
The [runtime `launch` command](docs/retail-runtime.md) selects its strategy from
the file version. Retail 12.x and later use the new strategy; its verified
Windows x64 recipes cover **12.0.7.68887** and **12.1.0.69587**.
Run `wow-patcher --help` to see all options. The most common invocations:
```bash
# Windows
wow-patcher -l "C:\Program Files\World of Warcraft\_retail_\Wow.exe"
# macOS (auto-detects WoW location)
wow-patcher
# Linux
wow-patcher -l ./Wow.exe -o ./wow-private
# Preview changes without modifying files
wow-patcher --dry-run -l ./Wow.exe
```
Platform-specific paths
### Windows
```bash
# Custom output location
wow-patcher -l "C:\Program Files\World of Warcraft\_retail_\Wow.exe" -o "D:\Games\WowTC.exe"
# Handle paths with spaces (use quotes)
wow-patcher -l "C:\Program Files (x86)\World of Warcraft\_retail_\Wow.exe" -o "C:\My Games\Wow Private.exe"
```
#### macOS
```bash
# Auto-detect WoW and keep code signing (not recommended)
wow-patcher -s=false
# Explicit path
wow-patcher -l "/Applications/World of Warcraft/_retail_/World of Warcraft.app/Contents/MacOS/World of Warcraft"
# Custom output name
wow-patcher -o WowTrinityCore
```
#### Linux
```bash
# Basic patching with custom output
wow-patcher -l /opt/wow/Wow.exe -o /home/user/games/wow-tc
# Wine installation example
wow-patcher -l "$HOME/.wine/drive_c/Program Files/World of Warcraft/_retail_/Wow.exe" -o ./WowPrivate.exe
```
Custom server / operator options
If you run your own server with custom keys or CDN URLs:
```bash
# Custom RSA modulus from a file (256 bytes)
wow-patcher -l ./Wow.exe --rsa-file ./custom_rsa.bin
# Custom CDN URLs
wow-patcher -l ./Wow.exe --version-url "http://my-cdn.example.com/versions"
# Custom portal domain
wow-patcher -l ./Wow.exe --bgs-portal-domain bgs.corp
# Inject a custom cert bundle
wow-patcher -l ./Wow.exe --rsa-file bundle-signing-modulus.bin \
--cert-bundle data/cert-bundle/bgs-key-fingerprint
```
See [docs/src/configuration.md](docs/src/configuration.md) for details.
Requirements
This tool will only work if you:
1. Are connecting to a server with a valid TLS certificate that chains to a
trusted root CA in your system trust store
2. Are using a hostname (not an IP address) for your portal cvar setting in
`WTF/Config.wtf`
## Building from Source
### Prerequisites
- Rust 1.92.0 or higher
- Cargo (included with Rust)
## FAQ
**Q: Why does this generate an exe with the name `Arctium` by default?**
**A:** In the event your client crashes, this helps Blizzard filter out
community-server traffic from their automated client telemetry.
**Q: Do I need to remove code signing on macOS?**
**A:** Yes, the patched executable needs code signing removed to run on macOS. This is enabled by default.
**Q: macOS shows a warning that the app is damaged or from an unidentified developer. How do I fix this?**
**A:** macOS adds a quarantine attribute to downloaded files. Remove it by running:
```bash
xattr -dr com.apple.quarantine /path/to/wow-patcher
```
If you built from source this is not needed.
**Q: Can I use this with any server?**
**A:** The patcher ships with TrinityCore-compatible defaults. If your server
uses custom keys or a custom certificate bundle, use `--rsa-file`,
`--cert-bundle`, and related flags. See `wow-patcher --help` or
[docs/src/configuration.md](docs/src/configuration.md).
## Acknowledgments
- Enormous thanks to [Fabian](https://github.com/Fabi)
from [Arctium](https://arctium.io/) for the knowledge that made this possible
- The TrinityCore team for their work on the server emulator
## Support the Project
If you find this project useful, please consider
[sponsoring the project](https://github.com/sponsors/danielsreichenbach).
This is currently a nights-and-weekends effort by one person. Funding goals:
- **20 hours/week** - Sustained funding to dedicate real development time
instead of squeezing it into spare hours
- **Public CDN mirror** - Host a community mirror for World of Warcraft builds,
ensuring long-term availability of historical game data
## Contributing
See the [Contributing Guide](CONTRIBUTING.md) for development setup and
guidelines.
## License
This project is dual-licensed under either:
- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or )
- MIT license ([LICENSE-MIT](LICENSE-MIT) or )
You may choose to use either license at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall
be dual licensed as above, without any additional terms or conditions.
---
**Note**: This project is not affiliated with Blizzard Entertainment. It is
an independent implementation based on reverse engineering by the World of
Warcraft emulation community.
[public-builds]: https://warcraft.wiki.gg/wiki/Public_client_builds