generate JWT RSA256 key pair using openssl

generate_jwtRSA256_key_pair.sh

# This RSA256 key is of 2048 bits long (valid between 1024-4096)
openssl genrsa -out jwtRSA256.private.key 2048
openssl rsa -in jwtRSA256.private.key -pubout -out jwtRSA256.public.key
# no need to input passphrase

cat jwtRSA256.private.key
cat jwtRSA256.public.key

# notice the jwtRSA256.public.key is in ssh-rsa format

NOTICE for PEM public key

For generating PEM public key, use this
-outform PEM

openssl rsa -in jwtRSA256.private.key -outform PEM -pubout -out jwtRSA256.public.key