Accepting a TLS server connection on the command line

Follow these steps for accepting a TLS server connection on the command line:

1. To accept a TLS server connection, we will use the s_server subcommand of the openssl tool. Its documentation can be found on its man page:

   $ man openssl-s_server

2. We will provide a port number, a server certificate, and the corresponding server keypair to openssl s_server. That’s how we start a TLS server:

   $ openssl s_server \
       -port 4433 \
       -key server_keypair.pem \
       -cert server_cert.pem

3. To check that our TLS server can accept connections and send and receive data over them, we can start a TLS client in another terminal window and connect to our TLS server:

   $ openssl s_client \
       -connect localhost:4433 \
       -verify_return_error \
       -verify_hostname localhost \
       -CAfile ca_cert...