487 lines
14 KiB
Markdown
487 lines
14 KiB
Markdown
letsencrypt
|
|
===========
|
|
|
|
Automatic [Let's Encrypt](https://lettsencrypt.org) HTTPS Certificates for node.js
|
|
|
|
* Automatic HTTPS with ExpressJS
|
|
* Automatic live renewal (in-process)
|
|
* On-the-fly HTTPS certificates for Dynamic DNS (in-process, no server restart)
|
|
* Works with node cluster out of the box
|
|
* usable via commandline as well
|
|
* Free SSL (HTTPS Certificates for TLS)
|
|
* [90-day certificates](https://letsencrypt.org/2015/11/09/why-90-days.html)
|
|
|
|
Install
|
|
=======
|
|
|
|
```bash
|
|
npm install --save letsencrypt
|
|
```
|
|
|
|
Right now this uses [`letsencrypt-python`](https://github.com/Daplie/node-letsencrypt-python),
|
|
but it's built to be able to use a pure javasript version (in progress).
|
|
|
|
```bash
|
|
# install the python client (takes 2 minutes normally, 20 on a rasberry pi)
|
|
git clone https://github.com/letsencrypt/letsencrypt
|
|
pushd letsencrypt
|
|
|
|
./letsencrypt-auto
|
|
```
|
|
|
|
**moving towards a python-free version**
|
|
|
|
There are a few partially written javascript implementation, but they use `forge` instead of using node's native `crypto` and `ursa` - so their performance is outright horrific (especially on Rasbperry Pi et al). For the moment it's faster to use the wrapped python version.
|
|
|
|
Once the `forge` crud is gutted away it should slide right in without a problem. Ping [@coolaj86](https://coolaj86.com) if you'd like to help.
|
|
|
|
Usage Examples
|
|
========
|
|
|
|
Here's a small snippet:
|
|
|
|
```javascript
|
|
le.register({
|
|
domains: ['example.com', 'www.example.com']
|
|
, email: 'user@example.com'
|
|
, agreeTos: true
|
|
, webrootPath: '/srv/www/example.com/public'
|
|
}, function (err, certs) {
|
|
// do stuff
|
|
});
|
|
```
|
|
|
|
**However**, due to the nature of what this library does, it has a few more "moving parts"
|
|
than what makes sense to show in a minimal snippet.
|
|
|
|
### One Time Registration
|
|
|
|
* [commandline (standalone with "webroot")](https://github.com/Daplie/node-letsencrypt/blob/master/examples/commandline.js)
|
|
|
|
```bash
|
|
# manual standalone registration via commandline
|
|
# (runs against testing server on tls port 5001)
|
|
node examples/commandline.js example.com,www.example.com user@example.net agree
|
|
```
|
|
|
|
[`commandline-minimal`](https://github.com/Daplie/node-letsencrypt/blob/master/examples/commandline-minimal.js):
|
|
```javascript
|
|
'use strict';
|
|
|
|
var LE = require('letsencrypt');
|
|
var config = require('./config-minimal');
|
|
|
|
// Note: you should make this special dir in your product and leave it empty
|
|
config.le.webrootPath = __dirname + '/../tests/acme-challenge';
|
|
config.le.server = LE.stagingServer;
|
|
|
|
|
|
//
|
|
// Manual Registration
|
|
//
|
|
var le = LE.create(config.backend, config.le);
|
|
le.register({
|
|
agreeTos: true
|
|
, domains: ['example.com'] // CHANGE TO YOUR DOMAIN
|
|
, email: 'user@email.com' // CHANGE TO YOUR EMAIL
|
|
}, function (err) {
|
|
if (err) {
|
|
console.error('[Error]: node-letsencrypt/examples/standalone');
|
|
console.error(err.stack);
|
|
} else {
|
|
console.log('success');
|
|
}
|
|
|
|
plainServer.close();
|
|
tlsServer.close();
|
|
});
|
|
|
|
|
|
//
|
|
// Express App
|
|
//
|
|
var app = require('express')();
|
|
app.use('/', le.middleware());
|
|
|
|
|
|
//
|
|
// HTTP & HTTPS servers
|
|
// (required for domain validation)
|
|
//
|
|
var plainServer = require('http').createServer(app).listen(config.plainPort, function () {
|
|
console.log('Listening http', this.address());
|
|
});
|
|
|
|
var tlsServer = require('https').createServer({
|
|
key: config.tlsKey
|
|
, cert: config.tlsCert
|
|
, SNICallback: le.sniCallback
|
|
}, app).listen(config.tlsPort, function () {
|
|
console.log('Listening http', this.address());
|
|
});
|
|
```
|
|
|
|
### Express
|
|
|
|
Fully Automatic HTTPS with ExpressJS using Free SSL certificates from Let's Encrypt
|
|
|
|
* [Minimal ExpressJS Example](https://github.com/Daplie/node-letsencrypt/blob/master/examples/express-minimal.js)
|
|
|
|
```javascript
|
|
'use strict';
|
|
|
|
var LE = require('letsencrypt');
|
|
var config = require('./config-minimal');
|
|
|
|
// Note: you should make this special dir in your product and leave it empty
|
|
config.le.webrootPath = __dirname + '/../tests/acme-challenge';
|
|
config.le.server = LE.stagingServer;
|
|
|
|
//
|
|
// Automatically Register / Renew Domains
|
|
//
|
|
var le = LE.create(config.backend, config.le, {
|
|
sniRegisterCallback: function (args, expiredCert, cb) {
|
|
// Security: check that this is actually a subdomain we allow
|
|
// (otherwise an attacker can cause you to rate limit against the LE server)
|
|
|
|
var hostname = args.domains[0];
|
|
if (!/\.example\.com$/.test(hostname)) {
|
|
console.error("bad domain '" + hostname + "', not a subdomain of example.com");
|
|
cb(nul, null);
|
|
}
|
|
|
|
// agree to the LE TOS for this domain
|
|
args.agreeTos = true;
|
|
args.email = 'user@example.com';
|
|
|
|
// use the cert even though it's expired
|
|
if (expiredCert) {
|
|
cb(null, expiredCert);
|
|
cb = function () { /*ignore*/ };
|
|
}
|
|
|
|
// register / renew the certificate in the background
|
|
le.register(args, cb);
|
|
}
|
|
});
|
|
|
|
|
|
//
|
|
// Express App
|
|
//
|
|
var app = require('express')();
|
|
app.use('/', le.middleware());
|
|
|
|
|
|
//
|
|
// HTTP & HTTPS servers
|
|
//
|
|
require('http').createServer(app).listen(config.plainPort, function () {
|
|
console.log('Listening http', this.address());
|
|
});
|
|
|
|
require('https').createServer({
|
|
key: config.tlsKey
|
|
, cert: config.tlsCert
|
|
, SNICallback: le.sniCallback
|
|
}, app).listen(config.tlsPort, function () {
|
|
console.log('Listening http', this.address());
|
|
});
|
|
```
|
|
|
|
* [Full ExpressJS Example](https://github.com/Daplie/node-letsencrypt/blob/master/examples/express.js)
|
|
|
|
```bash
|
|
# clear out the certificates
|
|
rm -rf tests/letsencrypt.*
|
|
|
|
# automatic registration and renewal (certs install as you visit the site for the first time)
|
|
# (runs against testing server on tls port 5001)
|
|
node examples/express.js example.com,www.example.com user@example.net agree
|
|
```
|
|
|
|
```bash
|
|
# this will take a moment because it won't respond to the tls sni header until it gets the certs
|
|
curl https://example.com/
|
|
```
|
|
|
|
### non-root
|
|
|
|
If you want to run this as non-root, you can.
|
|
|
|
You just have to set node to be allowed to use root ports
|
|
|
|
```
|
|
# node
|
|
sudo setcap cap_net_bind_service=+ep /usr/local/bin/node
|
|
```
|
|
|
|
and then make sure to set all of of the following to a directory that your user is permitted to write to
|
|
|
|
* `webrootPath`
|
|
* `configDir`
|
|
* `workDir` (python backend only)
|
|
* `logsDir` (python backend only)
|
|
|
|
|
|
See Also
|
|
========
|
|
|
|
* See [Examples](https://github.com/Daplie/node-letsencrypt/tree/master/examples)
|
|
* [Let's Encrypt in (exactly) 90 seconds with Caddy](https://daplie.com/articles/lets-encrypt-in-literally-90-seconds/)
|
|
* [lego](https://github.com/xenolf/lego): Let's Encrypt for golang
|
|
|
|
API
|
|
===
|
|
|
|
* `LetsEncrypt.create(backend, bkDefaults, handlers)`
|
|
* `le.middleware()`
|
|
* `le.sniCallback(hostname, function (err, tlsContext) {})`
|
|
* `le.register({ domains, email, agreeTos, ... }, cb)`
|
|
* `le.fetch({domains, email, agreeTos, ... }, cb)`
|
|
* `le.validate(domains, cb)`
|
|
* `le.registrationFailureCallback(err, args, certInfo, cb)`
|
|
|
|
### `LetsEncrypt.create(backend, bkDefaults, handlers)`
|
|
|
|
#### backend
|
|
|
|
Currently only `letsencrypt-python` is supported, but we plan to work on
|
|
native javascript support in February or so (when ECDSA keys are available).
|
|
|
|
If you'd like to help with that, see **how to write a backend** below and also
|
|
look at the wrapper `backend-python.js`.
|
|
|
|
**Example**:
|
|
```javascript
|
|
{ fetch: function (args, cb) {
|
|
// cb(err) when there is an actual error (db, fs, etc)
|
|
// cb(null, null) when the certificate was NOT available on disk
|
|
// cb(null, { cert: '<fullchain.pem>', key: '<privkey.pem>', renewedAt: 0, duration: 0 }) cert + meta
|
|
}
|
|
, register: function (args, setChallenge, cb) {
|
|
// setChallenge(hostnames, key, value, cb) when a challenge needs to be set
|
|
// cb(err) when there is an error
|
|
// cb(null, null) when the registration is successful, but fetch still needs to be called
|
|
// cb(null, cert /*see above*/) if registration can easily return the same as fetch
|
|
}
|
|
}
|
|
```
|
|
|
|
#### bkDefualts
|
|
|
|
The arguments passed here (typically `webpathRoot`, `configDir`, etc) will be merged with
|
|
any `args` (typically `domains`, `email`, and `agreeTos`) and passed to the backend whenever
|
|
it is called.
|
|
|
|
Typically the backend wrapper will already merge any necessary backend-specific arguments.
|
|
|
|
**Example**:
|
|
```javascript
|
|
{ webrootPath: __dirname, '/acme-challenge'
|
|
, fullchainTpl: '/live/:hostname/fullchain.pem'
|
|
, privkeyTpl: '/live/:hostname/fullchain.pem'
|
|
, configDir: '/etc/letsencrypt'
|
|
}
|
|
```
|
|
|
|
Note: `webrootPath` can be set as a default, semi-locally with `webrootPathTpl`, or per
|
|
regesitration as `webrootPath` (which overwrites `defaults.webrootPath`).
|
|
|
|
#### handlers *optional*
|
|
|
|
`h.setChallenge(hostnames, name, value, cb)`:
|
|
|
|
default is to write to fs
|
|
|
|
`h.getChallenge(hostnames, value cb)`
|
|
|
|
default is to read from fs
|
|
|
|
`h.sniRegisterCallback(args, currentCerts, cb)`
|
|
|
|
The default is to immediately call `cb(null, null)` and register (or renew) in the background
|
|
during the `SNICallback` phase. Right now it isn't reasonable to renew during SNICallback,
|
|
but around February when it is possible to use ECDSA keys (as opposed to RSA at present),
|
|
registration will take very little time.
|
|
|
|
This will not be called while another registration is already in progress.
|
|
|
|
**SECURITY WARNING**: If you use this option with a custom `h.validate()`, make sure that `args.domains`
|
|
refers to domains you expect, otherwise an attacker will spoof SNI and cause your server to rate-limit
|
|
letsencrypt.org and get blocked. Note that `le.validate()` will check A records before attempting to
|
|
register to help prevent such possible attacks.
|
|
|
|
`h.validate(domains, cb)`
|
|
|
|
When specified this will override `le.validate()`. You will need to do this if the ip address of this
|
|
server is not one specified in the A records for your domain.
|
|
|
|
### `le.middleware()`
|
|
|
|
An express handler for `/.well-known/acme-challenge/<challenge>`.
|
|
Will call `getChallenge([hostname], key, cb)` if present or otherwise read `challenge` from disk.
|
|
|
|
Example:
|
|
```javascript
|
|
app.use('/', le.middleware())
|
|
```
|
|
|
|
### `le.sniCallback(hostname, function (err, tlsContext) {});`
|
|
|
|
Will call `fetch`. If fetch does not return certificates or returns expired certificates
|
|
it will call `sniRegisterCallback(args, currentCerts, cb)` and then return the error,
|
|
the new certificates, or call `fetch` a final time.
|
|
|
|
Example:
|
|
```javascript
|
|
var server = require('https').createServer({ SNICallback: le.sniCallback, cert: '...', key: '...' });
|
|
server.on('request', app);
|
|
```
|
|
|
|
### `le.register({ domains, email, agreeTos, ... }, cb)`
|
|
|
|
Get certificates for a domain
|
|
|
|
Example:
|
|
```javascript
|
|
le.register({
|
|
domains: ['example.com', 'www.example.com']
|
|
, email: 'user@example.com'
|
|
, webrootPath: '/srv/www/example.com/public'
|
|
, agreeTos: true
|
|
}, function (err, certs) {
|
|
// err is some error
|
|
|
|
console.log(certs);
|
|
/*
|
|
{ cert: "contents of fullchain.pem"
|
|
, key: "contents of privkey.pem"
|
|
, renewedAt: <date in milliseconds>
|
|
, duration: <duration in milliseconds (90-days)>
|
|
}
|
|
*/
|
|
});
|
|
```
|
|
|
|
### `le.isValidDomain(hostname)`
|
|
|
|
returns `true` if `hostname` is a valid ascii or punycode domain name.
|
|
|
|
(also exposed on the main exported module as `LetsEncrypt.isValidDomain()`)
|
|
|
|
### `le.validate(args, cb)`
|
|
|
|
Used internally, but exposed for convenience. Checks `LetsEncrypt.isValidDomain()`
|
|
and then checks to see that the current server
|
|
|
|
Called before `backend.register()` to validate the following:
|
|
|
|
* the hostnames don't use any illegal characters
|
|
* the server's actual public ip (via api.apiify.org)
|
|
* the A records for said hostnames
|
|
|
|
### `le.fetch(args, cb)`
|
|
|
|
Used internally, but exposed for convenience.
|
|
|
|
Checks in-memory cache of certificates for `args.domains` and calls then calls `backend.fetch(args, cb)`
|
|
**after** merging `args` if necessary.
|
|
|
|
### `le.registrationFailureCallback(err, args, certInfo, cb)`
|
|
|
|
Not yet implemented
|
|
|
|
Backends
|
|
--------
|
|
|
|
* [`letsencrypt-python`](https://github.com/Daplie/node-letsencrypt-python) (complete)
|
|
* [`letiny`](https://github.com/Daplie/node-letiny) (in progress)
|
|
|
|
#### How to write a backend
|
|
|
|
A backend must implement (or be wrapped to implement) this API:
|
|
|
|
* `fetch(hostname, cb)` will cb(err, certs) with certs from disk (or null or error)
|
|
* `register(args, challengeCb, done)` will register and or renew a cert
|
|
* args = `{ domains, email, agreeTos }` MUST check that agreeTos === true
|
|
* challengeCb = `function (challenge, cb) { }` handle challenge as needed, call cb()
|
|
|
|
This is what `args` looks like:
|
|
|
|
```javascript
|
|
{ domains: ['example.com', 'www.example.com']
|
|
, email: 'user@email.com'
|
|
, agreeTos: true
|
|
, configDir: '/etc/letsencrypt'
|
|
, fullchainTpl: '/live/:hostname/fullchain.pem' // :hostname will be replaced with the domainname
|
|
, privkeyTpl: '/live/:hostname/privkey.pem'
|
|
, webrootPathTpl: '/srv/www/:hostname/public'
|
|
, webrootPath: '/srv/www/example.com/public' // templated from webrootPathTpl
|
|
}
|
|
```
|
|
|
|
This is what the implementation should look like:
|
|
|
|
(it's expected that the client will follow the same conventions as
|
|
the python client, but it's not necessary)
|
|
|
|
```javascript
|
|
return {
|
|
fetch: function (args, cb) {
|
|
// NOTE: should return an error if args.domains cannot be satisfied with a single cert
|
|
// (usually example.com and www.example.com will be handled on the same cert, for example)
|
|
if (errorHappens) {
|
|
// return an error if there is an actual error (db, etc)
|
|
cb(err);
|
|
return;
|
|
}
|
|
// return null if there is no error, nor a certificate
|
|
else if (!cert) {
|
|
cb(null, null);
|
|
return;
|
|
}
|
|
|
|
// NOTE: if the certificate is available but expired it should be
|
|
// returned and the calling application will decide to renew when
|
|
// it is convenient
|
|
|
|
// NOTE: the application should handle caching, not the library
|
|
|
|
// return the cert with metadata
|
|
cb(null, {
|
|
cert: "/*contcatonated certs in pem format: cert + intermediate*/"
|
|
, key: "/*private keypair in pem format*/"
|
|
, renewedAt: new Date() // fs.stat cert.pem should also work
|
|
, duration: 90 * 24 * 60 * 60 * 1000 // assumes 90-days unless specified
|
|
});
|
|
}
|
|
, register: function (args, challengeCallback, completeCallback) {
|
|
// **MUST** reject if args.agreeTos is not true
|
|
|
|
// once you're ready for the caller to know the challenge
|
|
if (challengeCallback) {
|
|
challengeCallback(challenge, function () {
|
|
continueRegistration();
|
|
})
|
|
} else {
|
|
continueRegistration();
|
|
}
|
|
|
|
function continueRegistration() {
|
|
// it is not necessary to to return the certificates here
|
|
// the client will call fetch() when it needs them
|
|
completeCallback(err);
|
|
}
|
|
}
|
|
};
|
|
```
|
|
|
|
LICENSE
|
|
=======
|
|
|
|
Dual-licensed MIT and Apache-2.0
|
|
|
|
See LICENSE
|