Greenlock™ for Express.js

An easy-to-use ACME client for Free SSL and Automated HTTPS.

| Sponsored by ppl | Greenlock™ for cli, cluster, Express.js, Koa, hapi

Features

• Automatic HTTPS
  • Free SSL
  • Free Wildcard SSL
  • Multiple domain support (up to 100 altnames per SAN)
  • Dynamic Virtual Hosting (vhost)
  • Automatical renewal (10 to 14 days before expiration)
• Great ACME support
  • ACME draft 11
  • Let's Encrypt v2
  • Let's Encrypt v1
• Full node.js support
  • core https module
  • Express.js
  • Koa
  • hapi
• Extensible Plugin Support
  • AWS (S3, Route53)
  • Azure
  • CloudFlare
  • Digital Ocean
  • etcd
  • Redis

Install

npm install --save greenlock-express@2.x

become a communityMember

If you're the kind of person that likes the kinds of stuff that I do, well, I want to do more of it and I'd like to get you involved.

When you set the communityMember option to true I save your email and I'm able to inform you when there are mandatory updates (such as with Let's Encrypt v2), notify you of important security issues, give you early access to similar projects, and get your feedback from time to time.

I'll also get a hash of domain names that receive and renew certificates, which is a metric that has long interested me and may help me in getting non-developers involved in this and future projects.

QuickStart

Screencast

Watch the QuickStart demonstration: https://youtu.be/e8vaR4CEZ5s

• 0:00 - Intro
• 2:22 - Demonstrating QuickStart Example
• 6:37 - Troubleshooting / Gotchas

Working Example Code

Here's a completely working example that will get you started.

git clone https://git.coolaj86.com/coolaj86/greenlock-express.js.git
pushd greenlock-express.js
  npm install
popd

# edit 'email' and 'approveDomains' in
# greenlock-express.js/examples/simple.js

node greenlock-express.js/examples/simple.js

All you have to do is start the webserver and then visit it at its domain name.

app.js:

'use strict';

require('greenlock-express').create({

  // Let's Encrypt v2 is ACME draft 11
  version: 'draft-11'

  // You MUST change 'acme-staging-v02' to 'acme-v02' in production
, server: 'https://acme-staging-v02.api.letsencrypt.org/directory'  // staging

  // You MUST change this to a valid email address
, email: 'john.doe@example.com'

  // You MUST NOT build clients that accept the ToS without asking the user
, agreeTos: true

  // You MUST change these to valid domains
  // NOTE: all domains will validated and listed on the certificate
, approveDomains: [ 'example.com', 'www.example.com' ]

  // You MUST have access to write to directory where certs are saved
  // ex: /home/foouser/acme/etc
, configDir: require('path').join(require('os').homedir(), 'acme', 'etc')

, app: require('express')().use('/', function (req, res) {
    res.setHeader('Content-Type', 'text/html; charset=utf-8')
    res.end('Hello, World!\n\n💚 🔒.js');
  })

  // Join the community to get notified of important updates and help me make greenlock better
, communityMember: true

//, debug: true

}).listen(80, 443);

What if the example didn't work?

Double check the following:

• Public Facing IP for http-01 challenges
  • Are you running this as a public-facing webserver (good)? or localhost (bad)?
  • Does ifconfig show a public address (good)? or a private one - 10.x, 192.168.x, etc (bad)?
  • If you're on a non-public server, are you using the dns-01 challenge?
• correct ACME version
  • Let's Encrypt v2 (ACME v2) must use version: 'draft-11'
  • Let's Encrypt v1 must use version: 'v01'
• valid email
  • You MUST set email to a valid address
  • MX records must validate (dig MX example.com for 'john@example.com')
• valid DNS records
  • You MUST set approveDomains to real domains
  • Must have public DNS records (test with dig +trace A example.com; dig +trace www.example.com for [ 'example.com', 'www.example.com' ])
• write access
  • You MUST set configDir to a writeable location (test with touch ~/acme/etc/tmp.tmp)
• port binding privileges
  • You MUST be able to bind to ports 80 and 443
  • You can do this via sudo or setcap
• API limits
  • You MUST NOT exceed the API usage limits per domain, certificate, IP address, etc
• Red Lock, Untrusted
  • You MUST change the server value in production
  • Shorten the 'acme-staging-v02' part of the server URL to 'acme-v02'

Get it working in staging first!

There are a number of common problems related to system configuration - firewalls, ports, permissions, etc - that you are likely to run up against when using greenlock for your first time.

In order to avoid being blocked by hitting rate limits with bad requests, you should always test against the staging server (https://acme-staging-v02.api.letsencrypt.org/directory) first.

Plugins

IMPORTANT: Community plugins may or may not be maintained and working. Please try with the defaults before switching to community plugins.

HTTP-01 Challenges

	Plugin
Build Your Own	le-challenge-http-SPEC
Default (fs)	le-challenge-fs
Full List	Search le-challenge- on npm
AWS S3	llun/le-challenge-s3
Digital Ocean	bmv437/le-challenge-digitalocean

DNS-01 Challenges

	Plugin
Build Your Own	le-challenge-dns-SPEC
Manual (cli)	le-challenge-fs
Full List	Search le-challenge- on npm
AWS Route 53	thadeetrompetter/le-challenge-route53
CloudFlare	buschtoens/le-challenge-cloudflare
CloudFlare	llun/le-challenge-cloudflare
Digital Ocean	bmv437/le-challenge-digitalocean
etcd	ceecko/le-challenge-etcd

Account & Certificate Storage

	Plugin
Build Your Own	le-store-SPEC
Defaults (fs)	le-store-certbot
Full List	Search le-store- on npm
AWS S3	paco3346/le-store-awss3
AWS S3	llun/le-store-s3
Azure	kolarcz/node-le-challenge-azure-storage
json (fs)	paulgrove/le-store-simple-fs
Redis	digitalbazaar/le-store-redis

Bugs: Please report bugs with the community plugins to the appropriate owner first, then here if you don't get a response.

Usage

The oversimplified example was the bait (because everyone seems to want an example that fits in 3 lines, even if it's terribly bad practices), now here's the switch.

We have another completely working example that will provides a little more to build off of.

git clone https://git.coolaj86.com/coolaj86/greenlock-express.js.git
pushd greenlock-express.js
  npm install
popd

# replace 'fooCheckDb' in
# greenlock-express.js/examples/normal.js

node greenlock-express.js/examples/normal.js

It looks a little more like this:

serve.js:

'use strict';

// returns an instance of greenlock.js with additional helper methods
var lex = require('greenlock-express').create({
  // set to https://acme-v02.api.letsencrypt.org/directory in production
  server: 'https://acme-staging-v02.api.letsencrypt.org/directory'
, version: 'draft-11' // Let's Encrypt v2 (ACME v2)

// If you wish to replace the default plugins, you may do so here
//
, challenges: { 'http-01': require('le-challenge-fs').create({ webrootPath: '/tmp/acme-challenges' }) }
, store: require('le-store-certbot').create({ webrootPath: '/tmp/acme-challenges' })

// You probably wouldn't need to replace the default sni handler
// See https://git.coolaj86.com/coolaj86/le-sni-auto if you think you do
//, sni: require('le-sni-auto').create({})

, approveDomains: approveDomains

  // Join the community to get notified of important updates and help me make greenlock better
, communityMember: true
});

The Automatic Certificate Issuance is initiated via SNI (httpsOptions.SNICallback). For security, domain validation MUST have an approval callback in production.

function approveDomains(opts, certs, cb) {
  // This is where you check your database and associated
  // email addresses with domains and agreements and such

  opts.communityMember = true;

  // The domains being approved for the first time are listed in opts.domains
  // Certs being renewed are listed in certs.altnames
  if (certs) {
    opts.domains = certs.altnames;
  }
  else {
    opts.email = 'john.doe@example.com';
    opts.agreeTos = true;
  }

  // NOTE: you can also change other options such as `challengeType` and `challenge`
  // opts.challengeType = 'http-01';
  // opts.challenge = require('le-challenge-fs').create({});

  cb(null, { options: opts, certs: certs });
}

// handles acme-challenge and redirects to https
require('http').createServer(lex.middleware(require('redirect-https')())).listen(80, function () {
  console.log("Listening for ACME http-01 challenges on", this.address());
});



var app = require('express')();
app.use('/', function (req, res) {
  res.end('Hello, World!');
});

// handles your app
require('https').createServer(lex.httpsOptions, lex.middleware(app)).listen(443, function () {
  console.log("Listening for ACME tls-sni-01 challenges and serve app on", this.address());
});

Security Warning:

If you don't do proper checks in approveDomains(opts, certs, cb) an attacker will spoof SNI packets with bad hostnames and that will cause you to be rate-limited and or blocked from the ACME server.

API

This module is an elaborate ruse (to provide an oversimplified example and to nab some SEO).

The API is actually located at greenlock.js options (because all options are simply passed through to greenlock.js proper without modification).

The only "API" consists of two options, the rest is just a wrapper around greenlock.js to take LOC from 15 to 5:

• opts.app An express app in the format function (req, res) { ... } (no next).
• lex.listen(plainPort, tlsPort) Accepts port numbers (or arrays of port numbers) to listen on.

Brief overview of some simple options for greenlock.js:

• opts.server set to https://acme-v02.api.letsencrypt.org/directory in production
• opts.version set to v01 for Let's Encrypt v1 or draft-11 for Let's Encrypt v2 (mistakenly called ACME v2)
• opts.email The default email to use to accept agreements.
• opts.agreeTos When set to true, this always accepts the LetsEncrypt TOS. When a string it checks the agreement url first.
• opts.communityMember Join the community to get notified of important updates and help make greenlock better
• opts.approveDomains can be either of:
  • An explicit array of allowed domains such as [ 'example.com', 'www.example.com' ]
  • A callback function (opts, certs, cb) { cb(null, { options: opts, certs: certs }); } for setting email, agreeTos, domains, etc (as shown in usage example above)
• opts.renewWithin is the maximum number of days (in ms) before expiration to renew a certificate.
• opts.renewBy is the minimum number of days (in ms) before expiration to renew a certificate.

Supported ACME versions

• Let's Encrypt v1 (aka v01)
• Let's Encrypt v2 (aka v02 or ACME draft 11)
• ACME draft 11 (ACME v2 is a misnomer)
• Wildcard domains (via dns-01 challenges)
  • *.example.com