LPIC-3 Security

An engineer needs to automate the issuance and renewal of publicly trusted TLS certificates for a web server without manually generating CSRs each time. According to the LPIC-3 cryptography objectives, which combination of technologies should the engineer study for this task?

A web administrator is configuring Apache HTTPD 2.4 with mod_ssl to reduce the number of round trips clients make when validating a server certificate's revocation status against an OCSP responder. Which mod_ssl feature addresses this goal?