This article explains how to create RSA public and private key pairs in PKCS#8 format.
This might be required if an upstream supplier asks you for the public in PKCS#8 format.
The key to achieving this is basically a three-step process:
1. Create key pair
openssl genrsa -out keypair.pem 2048
2. Extract public part
openssl rsa -in keypair.pem -pubout -out publickey.crt
At this point you have your public key called
3. Extract private part
openssl pkcs8 -topk8 -inform PEM -outform PEM -nocrypt -in keypair.pem -out pkcs8.key
At this point, you have your private key and it’s called