# Local OpenSSH test server

Runs a minimal **`sshd`** on **127.0.0.1:2222** (configurable) with **public-key authentication** only. No Docker.

## Requirements

- OpenSSH **server** binary (`sshd`) on the machine.
  - **macOS**: enable “Remote Login” in System Settings (installs/enables `sshd`), or `brew install openssh` and set `SSHD_BINARY` to the Homebrew `sshd`.
  - **Linux**: `openssh-server` (Debian/Ubuntu: `sudo apt install openssh-server`).

## Run

```bash
cd /path/to/bare-ssh2
chmod +x scripts/openssh-test-server/run.sh
./scripts/openssh-test-server/run.sh
```

Or from the repo root:

```bash
npm run openssh:test-server
```

Environment (optional):

| Variable               | Default                         | Meaning                          |
| ---------------------- | ------------------------------- | -------------------------------- |
| `OPENSSH_TEST_PORT`    | `2222`                          | TCP port                         |
| `OPENSSH_TEST_LISTEN`  | `127.0.0.1`                     | Bind address                     |
| `OPENSSH_TEST_RUNTIME` | `scripts/openssh-test-server/runtime` | Keys + config directory   |
| `SSHD_BINARY`          | (auto)                          | Full path to `sshd` if not found |

State is stored under **`scripts/openssh-test-server/runtime/`** (gitignored): host key, client key, `authorized_keys`, `sshd_config`.

## Connect

The server authenticates **your current OS username** using the generated client key:

```bash
KEY=scripts/openssh-test-server/runtime/client_ed25519
ssh -i "$KEY" -p 2222 -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null "$(id -un)@127.0.0.1"
```

## bare-ssh2 example

```js
const { readFileSync } = require('fs')
const { Client } = require('bare-ssh2')

const client = new Client()
client
  .on('ready', () => {
    client.exec('echo hello-from-server', (err, stream) => {
      if (err) throw err
      stream.on('close', () => client.end()).on('data', (d) => process.stdout.write(d))
    })
  })
  .connect({
    host: '127.0.0.1',
    port: 2222,
    username: require('os').userInfo().username,
    privateKey: readFileSync('scripts/openssh-test-server/runtime/client_ed25519'),
  })
```

## Notes

- **Foreground only**: the script runs `sshd -D -e` so logs go to the terminal; Ctrl+C stops it.
- If `sshd` complains about permissions or PAM, try running from a normal user session and ensure `StrictModes no` in the generated config (the script sets this).
- Some managed macOS profiles block custom `sshd`; use a Linux VM or Homebrew `openssh` in that case.