How can I create a self-signed cert for localhost?

chris picture chris · Nov 17, 2011 · Viewed 199.6k times · Source

I've gone through the steps detailed in How do you use https / SSL on localhost? but this sets up a self-signed cert for my machine name, and when browsing it via https://localhost I receive the IE warning.

Is there a way to create a self-signed cert for "localhost" to avoid this warning?

Answer

Ben Flynn picture Ben Flynn · Aug 23, 2015

Although this post is post is tagged for Windows, it is relevant question on OS X that I have not seen answers for elsewhere. Here are steps to create a self-signed cert for localhost on OS X:

# Use 'localhost' for the 'Common name'
openssl req -x509 -sha256 -nodes -newkey rsa:2048 -days 365 -keyout localhost.key -out localhost.crt

# Add the cert to your keychain
open localhost.crt

In Keychain Access, double-click on this new localhost cert. Expand the arrow next to "Trust" and choose to "Always trust". Chrome and Safari should now trust this cert. For example, if you want to use this cert with node.js:

var options = {
    key: fs.readFileSync('/path/to/localhost.key').toString(),
    cert: fs.readFileSync('/path/to/localhost.crt').toString(),
    ciphers: 'ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA:ECDHE-RSA-AES256-SHA384',
    honorCipherOrder: true,
    secureProtocol: 'TLSv1_2_method'
};

var server = require('https').createServer(options, app);