tl;dr of https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/configuring-https-ssl.html Used for many generating self-signed certificates for backend services and uploading to AWS ACM

ssl-alb

#!/bin/bash

# generate private key to create certificate signing request
# privatekey.pem
openssl genrsa 2048 >private.pem

# create a certificate signing request (CSR) 
# csr.pem
openssl req -new -key private.pem -out csr.pem

# sign the certificate (from CSR) 
# public.crt
openssl x509 -req -days 9999 -in csr.pem -signkey private.pem -out public.crt

# for windows servers - generate PFX certificate 
# public.pfx
openssl pkcs12 -export -out public.pfx -inkey private.pem -in public.crt

# Keep the private key and public certificate for later use.  
# Delete the signing request
rm csr.pem