openssl ec --help
https://docs.openssl.org/3.0/man1/openssl-ec/
    processes EC keys

baeldung
https://www.baeldung.com/category/security
https://www.baeldung.com/java-read-pem-file-keys
    !!!
https://www.baeldung.com/java-keystore-jks-list-private-keys

samples
openssl ec -in pvt.pem -pubout -out pub.pem