Update README.md

README.md

@@ -1,2 +1,76 @@
 # letsencrypt-koa
+
 Free SSL and Automatic HTTPS for node.js with KOA and other middleware systems via Let's Encrypt
+
+* Automatic Registration via SNI (`httpsOptions.SNICallback`)
+  * **registrations** require an **approval callback** in *production*
+* Automatic Renewal (around 80 days)
+  * **renewals** are *fully automatic* and happen in the *background*, with **no downtime**
+* Automatic vhost / virtual hosting
+
+All you have to do is start the webserver and then visit it at it's domain name.
+
+## Install
+
+```
+npm install --save letsencrypt-express
+```
+
+### Part 1: Setup
+
+```javascript
+'use strict';
+
+/* Note: using staging server url, remove .testing() for production
+Using .testing() will overwrite the debug flag with true */ 
+var LEX = require('letsencrypt-express').testing();
+
+var lex = LEX.create({
+  configDir: require('os').homedir() + '/letsencrypt/etc'
+, approveRegistration: function (hostname, cb) { // leave `null` to disable automatic registration
+    // Note: this is the place to check your database to get the user associated with this domain
+    cb(null, {
+      domains: [hostname]
+    , email: 'CHANGE_ME' // user@example.com
+    , agreeTos: true
+    });
+  }
+});
+```
+
+WARNING: If you don't do any checks and simply complete `approveRegistration` callback, 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. Alternatively, You can run registration *manually*:
+
+```bash
+npm install -g letsencrypt-cli
+
+letsencrypt certonly --standalone \
+  --config-dir ~/letsencrypt/etc \
+  --agree-tos --domains example.com --email user@example.com
+  
+# Note: the '--webrootPath' option is also available if you don't want to shut down your webserver to get the cert.
+```
+
+### Part 2: Just add Koa
+
+```javascript
+var http = require('http');
+var https = require('spdy');       // Note: some have reported trouble with `http2` and success with `spdy`
+var koa = require('koa');
+var app = koa();
+var redirectHttps = koa().use(require('koa-force-ssl').callback();
+
+app.use(function *() {
+  this.body = 'Hello World';
+});
+
+var server = https.createServer(lex.httpsOptions, LEX.createAcmeResponder(lex, app.callback()));
+var redirectServer = http.createServer(LEX.createAcmeResponder(lex, redirectHttps)));
+
+server.listen(443, function () {
+ console.log('Listening at https://localhost:' + this.address().port);
+});
+
+redirectServer.listen(80, function () {
+  console.log('Redirecting insecure traffic from http://localhost:' + this.address().port + ' to https');
+});
+```