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.
The "tls" option applies Scott Gifford's patch to implement UCSPI-TLS
in sslserver.