swgp

swgp-go

🐉 Simple WireGuard proxy with minimal overhead for WireGuard traffic.

Proxy modes

1. Zero overhead

• Encrypts the first 16 bytes as an AES block.
• Adds padding of random length to handshake packets, then encrypts all bytes after the first 16 using XChaCha20-Poly1305.

When to use

• ✅ Does not affect tunnel MTU.
• ✅ Minimal processing of data packets.

2. Paranoid

Packets are padded to the maximum packet size allowed by the MTU, then encrypted using XChaCha20-Poly1305.

When to use

• ✅ Full-packet AEAD.
• ✅ Hides in-tunnel packet sizes.
  • The length of a WireGuard data packet is always a multiple of 16.
  • Many IPv6 websites cap their outgoing MTU to 1280 for maximum compatibility.
• ❗️ Slight reduction of tunnel MTU.
• ❗️ Increased bandwidth usage.

Deployment

Arch Linux package

Release and VCS packages are available in the AUR:

Prebuilt binaries

Download from releases.

Container images

There are container images maintained by the community:

• vnxme/docker-swgp-go

Build from source

Build and install the latest version using Go:

go install github.com/database64128/swgp-go/cmd/swgp-go@latest

Or clone the repository and build it manually:

go build -trimpath -ldflags '-s -w' ./cmd/swgp-go

Configuration

All configuration examples and systemd unit files can be found in the docs directory.

swgp-go uses the same PSK format as WireGuard. A PSK can be generated using wg genpsk or openssl rand -base64 32.

Make sure to use the right MTU for both server and client. To encourage correct use, swgp-go disables IP fragmentation and drops packets that are bigger than expected.

1. Server

In this example, swgp-go runs a proxy server instance on port 20220. Decrypted WireGuard packets are forwarded to [::1]:20221.

{
    "servers": [
        {
            "name": "server",
            "proxyListen": ":20220",
            "proxyMode": "zero-overhead",
            "proxyPSK": "sAe5RvzLJ3Q0Ll88QRM1N01dYk83Q4y0rXMP1i4rDmI=",
            "proxyFwmark": 0,
            "wgEndpoint": "[::1]:20221",
            "wgFwmark": 0,
            "mtu": 1500
        }
    ]
}

2. Client

In this example, swgp-go runs a proxy client instance on port 20222. Encrypted proxy packets are sent to the proxy server at [2001:db8:1f74:3c86:aef9:a75:5d2a:425e]:20220.

{
    "clients": [
        {
            "name": "client",
            "wgListen": ":20222",
            "wgFwmark": 0,
            "proxyEndpoint": "[2001:db8:1f74:3c86:aef9:a75:5d2a:425e]:20220",
            "proxyMode": "zero-overhead",
            "proxyPSK": "sAe5RvzLJ3Q0Ll88QRM1N01dYk83Q4y0rXMP1i4rDmI=",
            "proxyFwmark": 0,
            "mtu": 1500
        }
    ]
}

License

AGPL-3.0-or-later