TypeOfNaN

A one-line OpenSSL command to generate a self-signed SSL certificate

Nick Scialli
December 06, 2022

ads via Carbon Unlock the power of FinOps at scale. Download O'Reilly's Cloud FinOps. ads via Carbon

Sometimes we just need to generate a self-signed SSL cert quickly with minimal fuss. In my experience, this has been helpful in development environment setup—but I’m sure there are plenty of good uses.

Here is the one-line shell script I use to:

#!/bin/bash
openssl req  -nodes -new -x509  \
    -keyout ./cert/server.key \
    -out ./cert/server.cert \
    -subj "/C=US/ST=State/L=City/O=company/OU=Com/CN=www.testserver.local"

Okay, it’s several lines because I added line breaks for clarity, but you get the idea. With this command, you don’t get prompted for any additional information; the cert and private key are simply generated.

The key and cert are output in ./cert/server.key and ./cert/server.cert, respectively. Feel free to change those directories/filenames to better suit your needs.

Nick Scialli

Nick Scialli is a senior UI engineer at Microsoft.

© 2025 Nick Scialli