ssh port forwarding / ssh tunneling

I’ve always been curious on ssh port forwarding enough to experiment and learn it to be deadly enough. I currently have two machines that I’d like to test this with, both -L (local) and -R (remote).

I have a C7 host behind a router and a C8 host on the internet that I’ll be testing with.

Our set up is the following:

192.168.2.222:22 (c7 Host) <-> 192.168.2.1:* (router) <-> 159.203.99.198:22 (c8 host)

Local Forwarding

What I’m going to do is forward port 4444 on my c7 machine to connect to the c8 host on port 22 by launching the following on 192.168.2.222:

$ ssh -L 192.168.2.222:4444:159.203.99.198:22 localhost

At this point I can start a SSH session to 192.168.2.222 at port 4444. I’m prompted to log in at 159.203.99.198, and i’m good to go. As long as the command is running I maintain a connection.

To remove the login necessity I added ~/.ssh/id_rsa.pub to ~/.ssh/authorized_keys for passwordless local log in.

Remote Forwarding

Remote forwarding allows world-accessible hosts to provide access to internal hosts. In our previous scenario we forwarded from an intranetwork host to a world host. Now we’re gonna use that intranetwork host and make it so that if we SSH to the world host at port 4444 that we will be ssh-ing to our intranetwork host, bypassing the router.

On 192.168.2.222 I execute the following:

$ ssh -R 4444:localhost:22 159.203.99.198 -ldiffuser

On my world-accessible host I log in with “diffuser”, and the forwarding is set up.

On 159.203.99.198 I can ssh to localhost:4444 and connect as internaluser with ease:

$ ssh localhost -p 4444 -linternaluser

Due to how /etc/ssh/sshd_config has GatewayPorts set up by default I cannot connect with my home computer to my world-accessible host. I would have to restart sshd service after setting GatewayPorts=yes (by default it’s no)

Flash Flashcard to HTML5

One of the awesome things about hoarding old images and video from the “good old” days is having the ability to bring new life to them. In 2018 I had re-released a friends work that he did for me in April 2013 by re-posting the flash videos that were made. Little did I know that flash would go the way of the dodo bird and browsers would shun files.

As an 8th-year “octoversary” I decided to dig down into my old files and grab the original images and audio and bring new life to them. I spent a small, but worthwhile, amount of time generating some reusable code to convert flashcard-style flash presentations to HTML5. This is now done over on T.C. in 2013, and the result is somewhat magnificent.

Earlier in the course of the project we happened across a person who did voicework. She went by the name of “Shawty Luv” and was able to provide us some starter voicework with our fairs. It was initially proposed to her to do our “tutorials”, and she happily did it for 2500 rays ($175 USD at the time). She subsequently delivered goods in zip fashion on 26 Feb 2013.

I decided to compile them together and bring them new life here:

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