In this web content, the author explains how to pass SSH through HTTPS in order to access blocked TCP ports. The author provides specific examples of client and server configurations, including the use of the ProxyCommand directive in openssh. They also discuss other options such as the sslh project and encapsulating one protocol into another. The author highlights the unique and clever workaround of using the CONNECT method to wrap TCP payload streams into TLS host streams. They also mention the usefulness of the ServerAliveInterval openssh knob for maintaining the connection. The author concludes by emphasizing the ubiquity of HTTPS and the potential for passing data through restrictive middle boxes.
https://trofi.github.io/posts/295-ssh-over-https.html