title: How to create .pem files for https web server
body: <p>I'm using the Express framework in Node.js to create a web server. I want to use ssl for the web server's connection.</p>
  <p>The code to create the https web server is as below.</p>
  <pre><code>var app = express.createServer({
    key: fs.readFileSync('./conf/key.pem'),
    cert: fs.readFileSync('./conf/cert.pem')
  });
  module.exports = app;
  </code></pre>
  <p>Question: How to create the key.pem and cert.pem required by express?</p>