SSL over UDP - Nginx as reverse proxy
HTTPS is HTTP using SSL/TLS security. SSL/TLS typically runs on top of TCP, but there is nothing to stop you from running it on UDP, SCTP or any other transport layer protocol. As a matter of fact HTTPS over TCP and UDP are both defined as "well known" by IANA and have reserved port numbers. tls - Is HTTPS over UDP secure? - Information Security HTTPS over UDP is secure. This is because the security of HTTPS doesn't use any of the properties of TCP except that it is a transport layer. Just like UDP, TCP is easy to spoof and manipulate. TCP is only to make things more reliable, not more secure. With UDP, packets can … Testing Sophos SSL VPN Performance - UDP or TCP? SSL VPN over UDP still attempts to connect to the VPN server on port 443, but unlike HTTPS traffic that uses TCP as a transport protocol, it uses UDP. Some firewalls and proxies may flag this as suspicious and drop the traffic. It can also be seen as peer-to-peer traffic (which it … TCP Over SSL Tunnel download | SourceForge.net
Because SSL can use TCP  to transport SSL records, and so SSL relies on TCP as a service. That is, SSL takes the user data stream, and converts it into a series of records; it then gives these records to TCP to transmit. On the other side, the receiver's TCP stack gets these records and gives it to SSL to decrypt.
Secure Sockets Layer (SSL) Protocol Overview
Can I forward UDP services over stunnel? As described thus far, no. Stunnel works with SSL, which runs only on TCP. There are ways to forward UDP packets over TCP, and in principle these should be able to work over stunnel. There are also other programs that do this natively, and could be used standalone or via stunnel, such as Zebedee.
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