OpenSSL 3 · Keys and signing requests

Create a certificate signing request

Generate a key and a CSR to send to a certificate authority, with the domain in the subject alternative name.

openssl req -new -newkey rsa:2048 -nodes -keyout server.key -out server.csr -subj "/CN=example.com" -addext "subjectAltName=DNS:example.com,DNS:www.example.com"

Official OpenSSL 3 documentation

More keys and signing requests commands

Check the OpenSSL version
Generate an RSA private key
Generate an elliptic curve key
Inspect a CSR
Extract the public key

All keys and signing requests commands · OpenSSL 3 cheatsheet