A simple certificate tool.
Mostly just binding to OpenSSL and creating/inspecting certificates with the least user interaction possible. There are other tools that take a similar approach but they either do too little (only self-signed certs, no self-CA-signed ones) or too much (install themselves by default into various system certificate stores). Plus it was an interesting way to learn more about the OpenSSL APIs and certificates.
I want to finish the Rustls version.