Valid SSL certificates for local development

A few weeks ago I bumped into mkcert, a tool written by Filippo, the same guy behind the popular heartbleed test tool.

The tool in question answers one simple need:

By creating a local root CA file that gets installed in your system, making all certificates issued by mkcert trusted:

After downloading the latest release from Github you can simply “install” it by running mkcert -install. Once that is done, you can create your first, trusted (by your own system) certificate:

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$ mkcert somedomain.local

Using the local CA at "/home/alex/.local/share/mkcert" ✨

Created a new certificate valid for the following names 📜
 - "somedomain.local"

The certificate is at "./somedomain.local.pem" and the key at "./somedomain.local-key.pem" ✅

For example, here’s how it would look like if you had to boot a node server with SSL support:

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const fs = require('fs')

const options = {
  key: fs.readFileSync(__dirname + '/somedomain.local-key.pem'),
  cert: fs.readFileSync(__dirname + '/somedomain.local.pem')
};

require('https').createServer(options, (req, res) => {
  res.writeHead(200)
  res.end(`Got SSL?`)
}).listen(443)

Pretty neat, ah? What mkcert does is to simply add another CA file in your system (I guess under /etc/ssl/certs/ca-certificates.crt, but I’m not entirely sure) so that browsers consider these certificates trusted — a nice workaround to trick any HTTP client.

Adios!