Generate public and private key pair

keygen.sh

#!/usr/bin/env bash

# generate a 2048-bit RSA private key
openssl genrsa -out private_tmp_key.pem 2048

# convert private Key to PKCS#8 format (so Java can read it)
openssl pkcs8 -topk8 -inform PEM -in private_tmp_key.pem -out private_key.pem -nocrypt

# generate a public key from the private one
openssl rsa -pubout -in private_tmp_key.pem -out public_key.pem

# cleanup
rm private_tmp_key.pem