smartssh/readme.md

# @push.rocks/smartssh

Secure SSH configuration, key management, and remote machine control for modern TypeScript projects. `@push.rocks/smartssh` gives you two things in one focused package: safe local OpenSSH config/key orchestration and a promise-first SSH client for executing commands, opening shells, transferring files, and forwarding ports.

Built on top of the pure JavaScript `ssh2` engine, it keeps the low-level protocol details out of your application while still exposing the control you need for serious automation.

## Issue Reporting and Security

For reporting bugs, issues, or security vulnerabilities, please visit [community.foss.global/](https://community.foss.global/). This is the central community hub for all issue reporting. Developers who sign and comply with our contribution agreement and go through identification can also get a [code.foss.global/](https://code.foss.global/) account to submit Pull Requests directly.

## Install

```bash
pnpm add @push.rocks/smartssh
```

## What It Does

- Manage SSH keys as typed `SshKey` objects.
- Generate OpenSSH-compatible config files with secure defaults.
- Read managed key material back from disk.
- Connect to remote machines with `SshClient`.
- Execute commands and collect stdout, stderr, exit code, and signal.
- Stream long-running commands or start interactive shells.
- Use SFTP for uploads, downloads, file reads, writes, stats, permissions, and directory operations.
- Forward TCP connections through SSH.
- Verify host keys by SHA256 or MD5 fingerprints, with explicit opt-out for disposable test systems.

## Quick Start

```typescript
import { SshClient, SshKey } from '@push.rocks/smartssh';

const privateKey = SshKey.fromFile('/home/deploy/.ssh/id_ed25519');

const sshClient = await SshClient.connect({
  host: 'server.example.com',
  username: 'deploy',
  privateKey,
  trustedHostFingerprints: ['SHA256:replaceWithYourKnownHostFingerprint'],
});

const result = await sshClient.exec('uname -a');

console.log(result.code);
console.log(result.stdout);
console.error(result.stderr);

await sshClient.close();
```

## Secure Defaults

`smartssh` is intentionally conservative:

- SSH config generation writes `StrictHostKeyChecking yes` by default.
- `SshClient.connect()` requires host validation by default.
- Private key files are written with `0600` permissions.
- Public key files are written with `0644` permissions.
- SSH directories are created with `0700` permissions.
- Host aliases are validated before they are used as filenames or config entries.

For local throwaway test servers you can explicitly opt out of host checking:

```typescript
const sshClient = await SshClient.connect({
  host: '127.0.0.1',
  username: 'tester',
  password: 'secret',
  strictHostKeyChecking: false,
});
```

Do not disable host checking for production infrastructure unless another trust layer is already enforcing host identity.

## Key Management

Create keys in memory:

```typescript
import { SshKey } from '@push.rocks/smartssh';

const githubKey = new SshKey({
  host: 'github.com',
  private: process.env.GITHUB_PRIVATE_KEY,
  public: process.env.GITHUB_PUBLIC_KEY,
});

console.log(githubKey.type); // 'duplex', 'private', 'public', or undefined
console.log(githubKey.privKeyBase64);
```

Load keys from files:

```typescript
const deployKey = SshKey.fromFile('/home/deploy/.ssh/id_ed25519');

const combinedKey = SshKey.fromFiles({
  host: 'production-app',
  privateKeyPath: '/home/deploy/.ssh/production-app',
  publicKeyPath: '/home/deploy/.ssh/production-app.pub',
});
```

Store keys safely:

```typescript
await combinedKey.store('/home/deploy/.ssh');
```

## OpenSSH Config Management

Use `SshInstance` when you want to manage a whole SSH directory and config file.

```typescript
import { SshInstance, SshKey } from '@push.rocks/smartssh';

const sshInstance = new SshInstance({
  sshDirPath: '/home/deploy/.ssh',
  strictHostKeyChecking: true,
});

sshInstance.addKey(
  new SshKey({
    host: 'git.example.com',
    private: process.env.GIT_PRIVATE_KEY,
    public: process.env.GIT_PUBLIC_KEY,
  })
);

sshInstance.writeToDisk();
```

Generated config example:

```sshconfig
Host git.example.com
  HostName git.example.com
  IdentityFile /home/deploy/.ssh/git.example.com
  StrictHostKeyChecking yes
```

Read keys back from disk:

```typescript
const existingSsh = new SshInstance({
  sshDirPath: '/home/deploy/.ssh',
});

existingSsh.readFromDisk();

const key = existingSsh.getKey('git.example.com');
console.log(key?.pubKey);
```

## Remote Command Execution

`exec()` waits for the remote command to finish and returns a structured result.

```typescript
const result = await sshClient.exec('systemctl is-active nginx', {
  timeout: 10_000,
});

if (result.code !== 0) {
  throw new Error(result.stderr);
}

console.log(result.stdout.trim());
```

Send input to a command:

```typescript
const result = await sshClient.exec('cat > /tmp/message.txt', {
  input: 'hello from smartssh\n',
});
```

Abort or time-limit a command:

```typescript
const abortController = new AbortController();

setTimeout(() => abortController.abort(), 5_000);

await sshClient.exec('sleep 60', {
  signal: abortController.signal,
});
```

## Streaming Commands and Shells

Use `stream()` for long-running commands where you want to handle output as it arrives.

```typescript
const stream = await sshClient.stream('tail -f /var/log/syslog');

stream.on('data', (chunk) => {
  process.stdout.write(chunk);
});

stream.stderr.on('data', (chunk) => {
  process.stderr.write(chunk);
});
```

Start an interactive shell:

```typescript
const shell = await sshClient.shell({
  window: {
    rows: 40,
    cols: 120,
    term: 'xterm-256color',
  },
});

shell.write('whoami\n');
shell.write('exit\n');
```

## SFTP

Create an SFTP client from an active SSH connection:

```typescript
const sftp = await sshClient.sftp();
```

Upload and download files:

```typescript
await sftp.upload({
  localPath: './dist/app.tar.gz',
  remotePath: '/tmp/app.tar.gz',
});

await sftp.download({
  remotePath: '/var/log/app.log',
  localPath: './app.log',
});
```

Read and write remote files:

```typescript
const osRelease = await sftp.readFile('/etc/os-release', 'utf8');

await sftp.writeFile('/tmp/deploy.json', JSON.stringify({
  version: '1.2.3',
}));
```

Inspect and manage remote paths:

```typescript
const files = await sftp.readdir('/var/www');
const stats = await sftp.stat('/var/www/app');

await sftp.mkdir('/tmp/smartssh');
await sftp.chmod('/tmp/smartssh', 0o755);
await sftp.rename('/tmp/old-name', '/tmp/new-name');
await sftp.remove('/tmp/new-name');
```

## Port Forwarding

Open a direct TCP channel through the SSH server:

```typescript
const channel = await sshClient.forwardOut({
  destinationHost: '127.0.0.1',
  destinationPort: 5432,
});

channel.write('raw tcp payload');
```

Ask the remote SSH server to listen and forward incoming TCP connections:

```typescript
const forward = await sshClient.forwardIn({
  remoteHost: '127.0.0.1',
  remotePort: 0,
});

console.log(`Remote port: ${forward.remotePort}`);

await forward.close();
```

## API Overview

### `SshClient`

- `SshClient.connect(profile)` creates and connects a client in one step.
- `connect()` opens the SSH connection for an existing instance.
- `exec(command, options)` runs a command and returns `ISshExecResult`.
- `stream(command, options)` opens a command channel for streaming output.
- `shell(options)` starts an interactive shell channel.
- `sftp()` returns a typed `SshSftpClient`.
- `forwardOut(options)` opens a direct TCP channel through SSH.
- `forwardIn(options)` creates a remote listener and returns a closeable handle.
- `close()` ends the connection.
- `fingerprintSha256(key)` and `fingerprintMd5(key)` generate comparable host key fingerprints.

### `SshSftpClient`

- `upload({ localPath, remotePath })`
- `download({ remotePath, localPath })`
- `readFile(remotePath, encoding?)`
- `writeFile(remotePath, data)`
- `readdir(remotePath)`
- `stat(remotePath)` and `lstat(remotePath)`
- `mkdir(remotePath, attributes?)`
- `chmod(remotePath, mode)`
- `rename(sourcePath, destinationPath)`
- `remove(remotePath)` and `rmdir(remotePath)`

### `SshKey`

- Construct with `{ host, private, public, authorized }`.
- Read and write private/public key strings.
- Encode and decode key material with `privKeyBase64` and `pubKeyBase64`.
- Load keys from disk with `fromFile()` or `fromFiles()`.
- Store keys to disk with safe permissions via `store()`.
- Inspect `type` as `duplex`, `private`, `public`, or `undefined`.

### `SshInstance`

- `addKey(key)`, `removeKey(key)`, and `replaceKey(oldKey, newKey)` manage key collections.
- `getKey(host)` retrieves a managed key by host alias.
- `sshKeys` exposes the current key array.
- `writeToDisk(dirPath?)` writes keys and config.
- `readFromDisk(dirPath?)` reads key files from an SSH directory.
- `sshSync: true` keeps disk state in sync on key changes.

### `SshConfig`

- `store(dirPath)` writes an OpenSSH config file.
- `read(dirPath)` reads the config file.
- `parse(dirPath)` parses host blocks from a config file.
- `SshConfig.parse(configString)` parses host blocks from a string.

## Types You Will Usually Import

```typescript
import type {
  ISshProfile,
  ISshExecOptions,
  ISshExecResult,
  ISshUploadOptions,
  ISshDownloadOptions,
  ISshForwardInHandle,
  ISshForwardInOptions,
  ISshForwardOutOptions,
  ISshShellOptions,
  TSshHostVerifier,
} from '@push.rocks/smartssh';
```

## Real-World Flow

```typescript
import { SshClient, SshKey } from '@push.rocks/smartssh';

const key = SshKey.fromFile('/home/deploy/.ssh/production');

const server = await SshClient.connect({
  host: 'app-01.example.com',
  username: 'deploy',
  privateKey: key,
  trustedHostFingerprints: ['SHA256:replaceWithTheRealFingerprint'],
  keepaliveInterval: 30_000,
});

try {
  const sftp = await server.sftp();

  await sftp.upload({
    localPath: './release.tar.gz',
    remotePath: '/tmp/release.tar.gz',
  });

  const deploy = await server.exec([
    'set -e',
    'mkdir -p /srv/app',
    'tar -xzf /tmp/release.tar.gz -C /srv/app',
    'systemctl restart app',
  ].join(' && '), {
    timeout: 120_000,
  });

  if (deploy.code !== 0) {
    throw new Error(deploy.stderr);
  }
} finally {
  await server.close();
}
```

## Notes

- The package is ESM-first and intended for TypeScript projects.
- `ssh2` is used directly as the SSH protocol engine.
- Config generation is intentionally simple and focused on managed host/key entries.
- `readFromDisk()` reads key files from the SSH directory; it does not attempt to preserve or rewrite arbitrary user-managed config comments.
- Host aliases are intentionally restricted to filename-safe values to avoid path traversal and config injection.

## License and Legal Information

This repository contains open-source code licensed under the MIT License. A copy of the license can be found in the [license](./license) file.

**Please note:** The MIT License does not grant permission to use the trade names, trademarks, service marks, or product names of the project, except as required for reasonable and customary use in describing the origin of the work and reproducing the content of the NOTICE file.

### Trademarks

This project is owned and maintained by Task Venture Capital GmbH. The names and logos associated with Task Venture Capital GmbH and any related products or services are trademarks of Task Venture Capital GmbH or third parties, and are not included within the scope of the MIT license granted herein.

Use of these trademarks must comply with Task Venture Capital GmbH's Trademark Guidelines or the guidelines of the respective third-party owners, and any usage must be approved in writing. Third-party trademarks used herein are the property of their respective owners and used only in a descriptive manner, e.g. for an implementation of an API or similar.

### Company Information

Task Venture Capital GmbH  
Registered at District Court Bremen HRB 35230 HB, Germany

For any legal inquiries or further information, please contact us via email at hello@task.vc.

By using this repository, you acknowledge that you have read this section, agree to comply with its terms, and understand that the licensing of the code does not imply endorsement by Task Venture Capital GmbH of any derivative works.