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Onion Pi Make a Raspberry Pi into a Anonymizing Tor Proxy!

Who is this good for?

If you want to browse anonymously on a netbook, tablet, phone, or other mobile or console device that cannot run Tor and does not have an Ethernet connection. If you do not want to or cannot install Tor on your work laptop or loan computer. If you have a guest or friend who wants to use Tor but doesn’t have the ability or time to run Tor on their computer, this gift will make the first step much easier.

What is Tor?

Tor is an onion routing service – every internet packet goes through 3 layers of relays before going to your destination. This makes it much harder for the server you are accessing (or anyone snooping on your Internet use) to figure out who you are and where you are coming from. It is an excellent way to allow people who are blocked from accessing websites to get around those restritions.

According to the Tor website:

Journalists use Tor to communicate more safely with whistleblowers and dissidents. Non-governmental organizations (NGOs) use Tor to allow their workers to connect to their home website while they’re in a foreign country, without notifying everybody nearby that they’re working with that organization.

Groups such as Indymedia recommend Tor for safeguarding their members’ online privacy and security. Activist groups like the Electronic Frontier Foundation (EFF) recommend Tor as a mechanism for maintaining civil liberties online. Corporations use Tor as a safe way to conduct competitive analysis, and to protect sensitive procurement patterns from eavesdroppers. They also use it to replace traditional VPNs, which reveal the exact amount and timing of communication. Which locations have employees working late? Which locations have employees consulting job-hunting websites? Which research divisions are communicating with the company’s patent lawyers?

A branch of the U.S. Navy uses Tor for open source intelligence gathering, and one of its teams used Tor while deployed in the Middle East recently. Law enforcement uses Tor for visiting or surveilling web sites without leaving government IP addresses in their web logs, and for security during sting operations.

BEFORE YOU START USING YOUR PROXY – remember that there are a lot of ways to identify you, even if your IP address is ‘randomized’. Delete & block your browser cache, history and cookies – some browsers allow “anonymous sessions”. Do not log into existing accounts with personally identifying information (unless you’re sure that’s what you want to do). Use SSL whenever available to end-to-end encrypt your communication. And read https://www.torproject.org/ for a lot more information on how to use Tor in a smart and safe way
This tutorial is a great way to make something fun and useful with your Raspberry Pi, but it is a work in progress. We can’t guarantee that it is 100% anonymous and secure! Be smart & paranoid about your Tor usage.

What you’ll need

You’ll need a few things to run this tutorial:

Chances are you’ve got a couple of these items already. If not, our Onion Pi starter pack has everything you need

raspberry_pi_onionpimini.jpg

Preparation

This tutorial assumes you have your Pi mostly set up and have followed our “Raspberry Pi as Wifi Access Point” tutorial

Please follow these tutorials in order to

Make sure to expand the filesystem to the entire disk or you may run out of space

raspberry_pi_expandFS.gif

When done you should have a Pi that is booting Raspbian, you can connect to with a USB console cable and log into the Pi via the command line interface.

When done you should be able to connect to the Pi as a WiFi access point and connect to the internet through it.

raspberry_pi_connecting.gif
It is possible to do this tutorial via ssh on the Ethernet port or using a console cable.

If using a console cable, even though the diagram on the last step shows powering the Pi via the USB console cable (red wire) we suggest not connecting the red wire and instead powering from the wall adapter. Keep the black, white and green cables connected as is.

raspberry_pi_gpio_closeup.jpg

Install Tor

Essentially, this tutorial just follows the tor “anonymizing middlebox” writeup here.

If you hate typing a lot, this script from breadk will do it all for you! Make sure to read through the script to make sure you don’t want to change anything! (More about how to use it here!) We do suggest going step by step so you can have the experience of all the upkeep tasks.

We’ll begin by installing tor – the onion routing software.

Log into your pi by Ethernet or console cable and run

 sudo apt-get update
sudo apt-get install tor

raspberry_pi_aptgettor.png
Edit the tor config file by running

 sudo nano /etc/tor/torrc

and copy and paste the text into the top of the file, right below the the FAQ notice.

Copy Code
  1. Log notice file /var/log/tor/notices.log
  2. VirtualAddrNetwork 10.192.0.0/10
  3. AutomapHostsSuffixes .onion,.exit
  4. AutomapHostsOnResolve 1
  5. TransPort 9040
  6. TransListenAddress 192.168.42.1
  7. DNSPort 53
  8. DNSListenAddress 192.168.42.1
raspberry_pi_torrc.png

Let’s edit the host access point so it is called something memorable like Onion Pi – don’t forget to set a good password, don’t use the default here!

sudo nano /etc/hostapd/hostapd.conf

(Don’t forget to do the AP setup step in “Preparation” before this!)

raspberry_pi_hostapd.png
Time to change our ip routing tables so that connections via the wifi interface (wlan0) will be routed through the tor software.
Type the following to flush the old rules from the ip NAT table

 sudo iptables -F
sudo iptables -t nat -F

If you want to be able to ssh to your Pi after this, you’ll need to add an exception for port 22 like this (not shown in the screenshot below)

 sudo iptables -t nat -A PREROUTING -i wlan0 -p tcp –dport 22 -j REDIRECT –to-ports 22

Type the following to route all DNS (UDP port 53) from interface wlan0 to internal port 53 (DNSPort in our torrc)

 sudo iptables -t nat -A PREROUTING -i wlan0 -p udp –dport 53 -j REDIRECT –to-ports 53

Type the following to route all TCP traffic from interface wlan0 to port 9040 (TransPort in our torrc)

 sudo iptables -t nat -A PREROUTING -i wlan0 -p tcp –syn -j REDIRECT –to-ports 9040

Next you can check that the ip tables are right with

 sudo iptables -t nat -L

raspberry_pi_iptables.png
If all is good, we’ll save it to our old NAT save file

 sudo sh -c “iptables-save > /etc/iptables.ipv4.nat”

It will automatically get loaded when the networking is set up on reboot (as we did in the last tutorial on making a Pi access point)

raspberry_pi_savetable.png
Next we’ll create our log file (handy for debugging) with

 sudo touch /var/log/tor/notices.log
sudo chown debian-tor /var/log/tor/notices.log
sudo chmod 644 /var/log/tor/notices.log

Check it with

 ls -l /var/log/tor

Start the tor service manually

 sudo service tor start

Check its really running (you can run this whenever you’re not sure, it something is wrong you’ll see a big FAIL notice

 sudo service tor status

Finally, make it start on boot

 sudo update-rc.d tor enable

raspberry_pi_runtor.png
That’s it, now you’re ready to test in the next step.

Test It!

OK now the fun part! It’s time to test your TOR anonymizing proxy. On a computer, check out the available wifi networks, you should see the Onion Pi network
raspberry_pi_onionpi.png
Connect to it using the password you entered into the hostapd configuration file
raspberry_pi_connecting.png
You can open up a Terminal or command prompt and ping 192.168.42.1 to check that your connection to the Pi is working. However you won’t be able to ping outside of it because ping’s are not translated through the proxy
raspberry_pi_ping192.gif
To check that the proxy is working, visit a website like http://www.ipchicken.com which will display your IP address as it sees it and also the matching domain name if available. The IP address should not be from your internet provider – in fact, if you reload the page it should change!
raspberry_pi_ipchicken.png
Your web browsing traffic is now anonymized!
BEFORE YOU START USING YOUR PROXY – remember that there are a lot of ways to identify you, even if your IP address is ‘randomized’. Delete your browser cache, history and cookies (some browsers allow “anonymous sessions”) and read https://www.torproject.org/ for a lot more information on how to use TOR in a smart and safe way