openssl genrsa -out private_key.pem 2048
openssl rsa -in private_key.pem -pubout -out public_key.pem
https://www.ibm.com/docs/en/api-connect/5.0.x?topic=profiles-generating-pkcs12-file-certificate-authority https://www.baeldung.com/openssl-self-signed-cert https://www.digitalocean.com/community/tutorials/openssl-essentials-working-with-ssl-certificates-private-keys-and-csrs