sslserver and sslclient are command-line tools for building SSL client-server applications.
They conform to the UNIX Client-Server Program Interface, UCSPI.
sslserver listens for connections, and runs a program for each connection it accepts.
The program environment includes variables that hold the local and remote host names, IP
addresses, and port numbers. sslserver offers a concurrency limit on acceptance of new
connections, and selective handling of connections based on client identity.
sslclient requests a connection to a TCP socket, and runs a program. The program
environment includes the same variables as for sslserver.