Well explained videos about digital certificates by Dave Crabbe: https://www.youtube.com/watch?v=qXLD2UHq2vk https://www.youtube.com/watch?v=heacxYUnFHA To add a self-signed .crt to trusted store in Fedora: https://docs.fedoraproject.org/en-US/quick-docs/using-shared-system-certificates/#proc_managing-trusted-system-certificates