stunnel: stunnel - multiplatform SSL tunneling proxy
The stunnel program 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 libraries for cryptography, so it supports whatever cryptographic algorithms you compiled into your library.
Stunnel can benefit from FIPS 140-2 certification of the OpenSSL library, as long as the building process meets its Security Policy. A scanned FIPS 140-2 Validation Certificate document is also available for download on the NIST web page. FIPS 140-2 support is currently available (and enabled by default) in the Windows version of stunnel.
Stunnel is a free software authored by Michal Trojnara. Although distributed under GNU GPL version 2 or later with OpenSSL exception, stunnel is not a community project. We retain the copyright of the source code. Please contact us for support or non-GPL licenses.
The obsolete 3.x branch is no longer maintained. Use stunnel3 perl script as a drop-in replacement for backward compatibility.