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.

Homepage:
https://www.fehcom.de/ipnet/ucspi-ssl.html
