Tor (which stands for The Onion Router), is a powerful anonymity service originally developed by the US Navy, which helps protect citizens around the world from abuse and monitoring.

Most people use Tor via the Tor Browser, which simplifies setup, and I encourage you to use that where you can. This article discusses going one step further, and routing all traffic through Tor via the use of a HTTP proxy.

In the UK, the passage of the disastrous #IPBill places everyone under suspicionless surveillance, and I have client confidentiality to consider. So, as a matter of due diligence, I wanted to ensure that when my ISP’s surveillance database was inevitably hacked, the information the Russian Mafia got was of limited use.

This was easy enough to set up.

Install and configure Tor

The first step is to install Tor; not the browser, but the software the browser talks to in order to make it’s connection. On Debian based systems, apt-get install tor.

Tor comes with a SOCKS proxy, so enable support by editing /etc/tor/torrc and uncomment the line:

If this is a network server, you may want to enable an external proxy on your network as well (for example, I have an always on Raspberry Pi running a tor proxy for all the various iOS devices on my home network).

Chain a simple HTTP Proxy

Once that’s done, you’ll have a SOCKS proxy up and running that’ll route anything it gets through Tor. Many things (e.g. the aforementioned iOS devices) won’t talk SOCKS. To solve this, I use a light weight HTTP proxy called polipo to create a HTTP proxy wrapper for Tor’s SOCKS proxy.

Install polipo: apt-get install polipo

Then configure the proxy to chain to Tor’s SOCKS proxy, modify /etc/polipo/config:

On my Raspberry Pi, I also disable the caching by adding diskCacheRoot = "" to the config, as this prevents polipo from filling up the SD card and breaking the proxy.

Restart both tor and polipo, and now you should have both a tor SOCKS and HTTP proxy.

Change your browser settings

Finally, you need to configure your browser (or your entire system) to use this proxy. This is different depending on what you’re using, but on Ubuntu you can set global proxy settings in your system settings, which will route all traffic over your new proxy (default port 8123).

iOS devices have a per-network proxy configuration found in your wireless network configuration (click on the little “i” icon).

Verify everything is working by visiting check.torproject.org.

On the Indiewebcamp wiki, there’s a page discussing HTTPS, the support for which is strongly recommended. As I’ve mentioned previously, at this stage all non-encrypted communication forms (including traditional port 80 HTTP) should be considered deprecated and dangerous.

Indieweb compatible sites are encouraged to get a higher level as possible, and thanks to some prodding, I’ve finally moved both this blog and my feed over to HTTPS only, with HSTS and forward secrecy.

This got me thinking, perhaps it would be worth adding a “Level 7” (or perhaps Level 6.5) to this, and to suggest that Indieweb sites should also be made available as .onion hidden services on Tor?

Pros

  • Anonymity. Would go a large way towards protecting communication metadata (who know’s whom), which is a goal we should move towards in a world of endemic selector based surveillance.
  • Encryption. Traffic within the tor network is end to end encrypted, and there is some discussion of whether this renders HTTPS unnecessary.

Cons

  • Tor has nothing to do with HTTPS, although it is encrypted. However, the HTTPS levels page seemed a good place to put the suggestion.
  • Could be seen as endorsing one service. Tor is Free software and is pretty much the only game in town when it comes to anonymity networks, but does that constitute a silo? Probably not, but is a point for discussion.
  • No certificates for .onion. There are currently no certificate providers available for .onion domains. But, this may not be a problem.

Anyway, just mooting this as a point for discussion.

Tor is a powerful anonymity tool that lets people communicate and share ideas without disclosing who they are or what they’re viewing to prying eyes.

One cool thing that the network lets you do is create a site as a hidden service, which is a service accessible only from within the tor network, is end to end encrypted and can be viewed entirely anonymously via a .onion domain.

I thought it could be cool to be able to run Known as a hidden service, and potentially build an entirely distributed social network, one that resists metadata surveillance as well as content surveillance. Anyway, baby steps…

Install Tor

The first thing you need to do is install tor. I don’t mean the tor browser, although you’ll need that to visit your hidden service, I mean the underlying tor program itself. On a debian based network this is really easy:

apt-get install tor

Next, you need to configure your hidden service(s) by editing the configuration in /etc/tor/torrc:

Restart tor and you will find a file containing your .onion domain name in /var/lib/tor/hidden_service/hostname. More details on configuring tor hidden services can be found on the tor project website.

Install Known

Download and install Known in the usual way.

My setup for my test onion site is Apache2 + modules + MariaDB (because I wanted to try Maria out). You of course can run nginx with mysql or mongodb, it won’t matter too much for tor.

To run through the Known installation procedure, you’ll need to visit your site via the tor browser. Find the name of your hidden service in /var/lib/tor/hidden_service/hostname (which will look something like xa7txi2q5okg36f6.onion), fire up your tor browser and visit that URL. All being well, you should see the Known installation.

Configuring Known to use tor

By default, Known will attempt to connect to web services and send webmentions directly. This will usually work if the machine you’re running your hidden service on is also directly connected to the internet, however you should consider routing this through tor since this communication could unmask your service.

So, you need to configure tor as a proxy, and then configure Known to use it.

First, edit torrc and add/uncomment the line:

Next, configure Known’s web services to use it. Add the following to your Known config.ini file:

These commands tell Known’s webservice calls to use the tor proxy to connect to the internet, and to use tor for DNS resolution in order to get access to .onion domains. This is important so that you are able to, among other things, send webmentions to other .onion sites from within the tor network. The last line disables ssl verification for HTTPS certificates (see the note below).

Note, for these settings to work you need to be running a version of Known that includes my curl settings patch.

Restart tor, and now all web service calls (which use Known’s web service library) should be sent via your tor proxy.

Known issues

There are some things you will need to consider when running Known as a hidden service:

  • The default PuSH hub is the public one at https://withknown.superfeedr.com/. This may cause unacceptable leakage of activity, so you may want to consider leaving this blank or using the Known native PuSH hub.
  • For the same reason, you may want to consider turning off emails, or sending emails through something like Mixmaster.
  • Only things that use Known’s web services libraries will use the proxy. Third party plugins (especially syndication plugins which use third party libraries, e.g. Facebook) will still try to connect directly. You may consider not using these plugins.
  • Currently there are no valid TLS certificates available for .onion domains, so you have to self sign if you want HTTPS. However, a .onion address is end to end encrypted in any case and there is some lively discussion about whether certificate authority based HTTPS is necessary or even desirable for hidden services. That you can’t get valid SSL certs for hidden services is a known problem (as opposed to a Known problem), so it’ll be resolved eventually one way or another.

Anyway, happy hacking!