stunnel is an open-source multi-platform application used to provide a universal TLS/SSL tunneling service.
stunnel can be used to provide secure encrypted connections for clients or servers that do not speak TLS or SSL natively. It runs on a variety of operating systems, including most Unix-like operating systems and Windows. stunnel relies on the OpenSSL library to implement the underlying TLS or SSL protocol.
stunnel uses public-key cryptography with X.509 digital certificates to secure the SSL connection, and clients can optionally be authenticated via a certificate.
If linked against libwrap, it can be configured to act as a proxy-firewall service as well.
stunnel is maintained by Michał Trojnara and released under the terms of the GNU General Public License (GPL) with OpenSSL exception.
Snaps are applications packaged with all their dependencies to run on all popular Linux distributions from a single build. They update automatically and roll back gracefully.
Snaps are discoverable and installable from the Snap Store, an app store with an audience of millions.
Snap is available for Linux Mint 18.2 (Sonya), Linux Mint 18.3 (Sylvia), Linux Mint 19 (Tara), Linux Mint 19.1 (Tessa) and the latest release, Linux Mint 20 (Ulyana).
You can find out which version of Linux Mint you’re running by opening System info from the Preferences menu.
On Linux Mint 20, /etc/apt/preferences.d/nosnap.pref needs to be removed before Snap can be installed. This can be accomplished from the command line: