Stunnel is designed to work as an SSL encryption wrapper between remote client and local (
inetd-startable) or remote server. It can be used to add SSL functionality to commonly used
inetd daemons like POP2, POP3, and IMAP servers without any changes in the programs' code. Stunnel uses OpenSSL or SSLeay libraries for cryptography, so it supports whatever cryptographic algorithms you compiled
...Licence : GPL