Stunnel is a program that allows you to encrypt arbitrary TCP connections inside SSL (Secure Sockets Layer) available on both Unix and Windows. Stunnel can allow you to secure non-SSL aware daemons and protocols (like POP, IMAP, NNTP, LDAP, etc) by having Stunnel provide the encryption, requiring no changes to the daemon’s code.
You can download it from the following link: https://packetstormsecurity.com/files/download/106186/stunnel-4.45.tar.gz
Source: https://packetstormsecurity.com/files/106186/Stunnel-SSL-Wrapper-4.45.html