# quicssh-rs

> :smile: **quicssh-rs** is a QUIC proxy that allows to use QUIC to connect to an SSH server without needing to patch the client or the server.

`quicssh-rs` is [quicssh](https://github.com/moul/quicssh) rust implementation. It is based on [quinn](https://github.com/quinn-rs/quinn) and [tokio](https://github.com/tokio-rs/tokio)

Why use QUIC? Because SSH is vulnerable in TCP connection environments, and most SSH packets are actually small, so it is only necessary to maintain the SSH connection to use it in any network environment. QUIC is a good choice because it has good weak network optimization and an important feature called connection migration. This means that I can switch Wi-Fi networks freely when remote, ensuring a stable SSH connection.

## Demo

https://user-images.githubusercontent.com/39181969/235409750-234de94a-1189-4288-93c2-45f62a9dfc48.mp4

## Why not mosh?

Because the architecture of mosh requires the opening of many ports to support control and data connections, which is not very user-friendly in many environments. In addition, vscode remote development does not support mosh.

## Architecture

Standard SSH connection

```
┌───────────────────────────────────────┐             ┌───────────────────────┐
│                  bob                  │             │         wopr          │
│ ┌───────────────────────────────────┐ │             │ ┌───────────────────┐ │
│ │           ssh user@wopr           │─┼────tcp──────┼▶│       sshd        │ │
│ └───────────────────────────────────┘ │             │ └───────────────────┘ │
└───────────────────────────────────────┘             └───────────────────────┘
```

---

SSH Connection proxified with QUIC

```
┌───────────────────────────────────────┐             ┌───────────────────────┐
│                  bob                  │             │         wopr          │
│ ┌───────────────────────────────────┐ │             │ ┌───────────────────┐ │
│ │ssh -o ProxyCommand "quicssh-rs    │ │             │ │       sshd        │ │
│ │ client quic://%h:4433             │ │             │ └───────────────────┘ │
│ │       user@wopr                   │ │             │           ▲           │
│ └───────────────────────────────────┘ │             │           │           │
│                   │                   │             │           │           │
│                process                │             │  tcp to localhost:22  │
│                   │                   │             │           │           │
│                   ▼                   │             │           │           │
│ ┌───────────────────────────────────┐ │             │┌─────────────────────┐│
│ │  quicssh-rs client wopr:4433      │─┼─quic (udp)──▶│   quicssh-rs server ││
│ └───────────────────────────────────┘ │             │└─────────────────────┘│
└───────────────────────────────────────┘             └───────────────────────┘
```

## Usage

```console
$ quicssh-rs -h
A simple ssh server based on quic protocol

Usage: quicssh-rs <COMMAND>

Commands:
  server  Server
  client  Client
  help    Print this message or the help of the given subcommand(s)

Options:
      --log <LOG_FILE>         Location of log, Default if
      --log-level <LOG_LEVEL>  Log level, Default Error
  -h, --help                   Print help
  -V, --version                Print version
```

### Client

```console
$ quicssh-rs client -h
Client

Usage: quicssh-rs client [OPTIONS] <URL>

Arguments:
  <URL>  Server address

Options:
  -b, --bind <BIND_ADDR>  Client address
  -h, --help              Print help
  -V, --version           Print version
```

#### Client SSH Config

```console
╰─$ cat ~/.ssh/config
Host test
    HostName test.test
    User root
    Port 22333
    ProxyCommand /Users/ouyangjun/code/quicssh-rs/target/release/quicssh-rs client quic://%h:%p

╰─$ ssh test
Last login: Mon May  1 13:32:15 2023 from 127.0.0.1
```

### Server

```console
$ quicssh-rs server -h
Server

Usage: quicssh-rs server [OPTIONS]

Options:
  -l, --listen <LISTEN>        Address to listen on [default: 0.0.0.0:4433]
  -p, --proxy-to <PROXY_TO>  Address of the ssh server [default: 127.0.0.1:22]
  -h, --help                   Print help
  -V, --version                Print version
```