ssh-key-generator

Generate OpenSSH-compatible RSA key material in Node.js.

Features

• 4096-bit RSA by default
• PEM private keys
• OpenSSH public key lines for:
  • authorized_keys
  • known_hosts
• Helpers for:
  • user/client keys
  • host keys

Install

npm install ssh-key-generator

Usage

import { writeFileSync } from 'node:fs';
import {
  createUserKeyPair,
  createHostKeyPair,
} from 'ssh-key-generator';

const userKeys = createUserKeyPair({
  comment: '[email protected]',
  passphrase: 'correct horse battery staple',
});

writeFileSync('id_rsa.pub', userKeys.publicKeyLine + '\n', { mode: 0o644 });
writeFileSync('id_rsa', userKeys.privateKeyPem, { mode: 0o600 });

const hostKeys = createHostKeyPair({
  comment: 'host.example.com',
  hosts: ['host.example.com', '192.0.2.10'],
});

writeFileSync('ssh_host_rsa_key.pub', hostKeys.publicKeyLine + '\n', { mode: 0o644 });
writeFileSync('ssh_host_rsa_key', hostKeys.privateKeyPem, { mode: 0o600 });

console.log(hostKeys.knownHostsLine);

Notes

• Host private keys are exported as unencrypted PEM PKCS#1.
• Client private keys default to PEM PKCS#8.
• Public keys are emitted in OpenSSH text format such as ssh-rsa AAAA... comment.