Reverse SSH Tunnel – when you cannot SSH to your host

Sometimes you need a workaround for SSH to an host. On my case, i cannot SSH to a ppp connected Raspberry Pi, but he can SSH to every other host. Solution is simple: ppp-Pi will SSH to a remote SSH server leaving a door open. Then i can SSH to my host, and login to my Pi. Confused? I know.

There’s a pretty good explanation on StackExchange.

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3G to WiFi Raspberry Pi gateway

[Edit]: Thanks Hackaday for the highlight! Part two of the hack – having a 77 year old learning how to use an Android phone – is ongoing. Proof of success: her instagram account.

After building my DIY 16.5 dBi (probably with pornographic levels of VSWR – hopefully i can get an antenna analyzer on that by the next few weeks) and proofing the concept of a feasible 3G gateway, i had to put everything inside a nice IP65 box and set it up outside. Initially i was aiming at using a modded WR703N with Rooter firmware and a Huawei E3131. After burning both of them, i had to resort to a Raspberry Pi Zero.

Principle of operation: Raspberry Pi handles the PPP session from the USB modem, creates an WiFi network via hostapd and uses iptables for the rest.

Notes on weatherproofing something

Basics first:

  • water + electronics = bad. Solution?
    • Sealed box.
  • heat + electronics = bad. Solution?
    • Sealed box with ventilation.
  • Sealed box with ventilation + electronics = moisture during low temperature. Solution?
    • Heat it when it’s cold.
  • 230VAC outside = bad idea. Solution?
    • Industrial grade 230VAC to 5VDC PSU – i used this one from Mean Well – RS-35-5 (link to manufacturer) placing it within the attic and routing 5m of 2×0.75mm2 cable outside – 6m total, minimum voltage drop.

So, this is not a trivial problem to solve. My solution? IP65 grade box (IP rating table right here) with a breathing hole, DHT22 sensor inside, DS18B20 outside, python measuring things. More details below…

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Temperature control (DS18B20 + DHT22) with the Raspberry Pi

In order to know what’s happening inside a semi sealed box, i used a small piece of perf board and added the DHT22 and DS18B20 with 10k pullups. I also added a small push button for safely powering off the Pi if needed. It looks something like this:

My take on a temperature HAT for DS18B20 and DHT22

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DIY 2100MHz / 3G Yagi Antenna

Part of my family lives in a very remote location. There’s only AM and FM radio, i need to boost DVB-T signals from a repeater 40km away, and the phone landline fails around a week a month (trees falling and stuff).

So i had the idea to build a 3G/Wifi gateway. I didn’t wanted to spend 30€ on a comercial antenna to check if i had the required signal so i built my own.

It’s important to state that this was a trial: this build was never intended as a final product since this yagi wouldn’t stand a chance to strong winds.

Finished v1.0 build.

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[Tutorial] Your own private anonymizing proxy – Raspberry Pi / TOR based

This howto uses the Raspberry Pi as the base system (tutorial is based on Debian), and Tor as the SOCKS5 Proxy.

The Objective: be anonymous on the internet, using the Raspberry Pi as a transparent SOCKS 5 proxy.

I didn’t intended this to be a completely exhaustive tutorial, but i feel it’s complete enough for the novice user to follow.

As a bonus, i’ve added info on how to use Tor as a Socks Proxy for your iPhone/iPad – no need to jailbreak.

If in any doubt following this guide, please leave a comment!


Sometimes, you need to anonymize yourself in the internet. Or you’re just paranoid and don’t want to be followed around.

Either way, a proxy is a great way to stay anonymous in the internet.

If you just want to browse around, you can download a full featured package with Tor, and its own stripped down version of Firefox called TorBrowser. There are versions for Linux, OS X, and Windows, and you’re ready to go.

But if you don’t want to install anything in every device you own, or you want to be anonymous on your iPhone or Android device, then, this tutorial is for you.


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[Tutorial] Web based SSH terminal for the Raspberry Pi

So, the other day, i wrote about Onion Terminal. Despite this is a great Terminal, it relies on Onion lib, and this has a lot of dependencies to it: libcairo-dev, libxml2, libpng++-dev, …

Then, i discovered GateOne – a full featured HTML5 based web terminal for SSH access.

Despite this tutorial is for the Raspberry Pi, this will work without much changes in any Debian based system, such as Ubuntu and others.

GateOne in action


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