generate public key from private key openssl code example
Example: Command to create the private key and public using the openssl command :
openssl genrsa -out private.pem 2048
openssl rsa -in private_key.pem -outform PEM -pubout public.pem
openssl genrsa -out private.pem 2048
openssl rsa -in private_key.pem -outform PEM -pubout public.pem