tor network

We, the Debian project and the Tor project are enabling Tor onion services for several of our sites. These sites can now be reached without leaving the Tor network, providing a new option for securely connecting to resources provided by Debian and Tor.

The freedom to use open source software may be compromised when access to that software is monitored, logged, limited, prevented, or prohibited. As a community, we acknowledge that users should not feel that their every action is trackable or observable by others. Consequently, we are pleased to announce that we have started making several of the various web services provided by both Debian and Tor available via onion services.

While onion services can be used to conceal the network location of the machine providing the service, this is not the goal here. Instead, we employ onion services because they provide end-to-end integrity and confidentiality, and they authenticate the onion service end point.

For instance, when users connect to the onion service running at http://sejnfjrq6szgca7v.onion/ using a Tor-enabled browser such as the TorBrowser, they can be certain that their connection to the Debian website cannot be read or modified by third parties, and that the website that they are visiting is indeed the Debian website. In a sense, this is similar to what using HTTPS provides. However, crucially, onion services do not rely on third-party certificate authorities (CAs). Instead, the onion service name cryptographically authenticates its cryptographic key.

In addition to the Tor and Debian websites, the Debian FTP and the Debian Security archives are available from .onion addresses, enabling Debian users to update their systems using only Tor connections. With the apt-transport-tor package installed, the following three lines can replace the normal debian mirror entries in the apt configuration file (/etc/apt/sources.list):

deb tor+http://vwakviie2ienjx6t.onion/debian jessie main
deb tor+http://vwakviie2ienjx6t.onion/debian jessie-updates main
deb tor+http://sgvtcaew4bxjd7ln.onion/debian-security jessie/updates main

Likewise, Tor's Debian package repository is available from an onion service :

deb tor+http://sdscoq7snqtznauu.onion/torproject.org jessie main

Where appropriate, we provide services redundantly from several backend machines using OnionBalance. The Debian OnionBalance package is available from the Debian backports repository.

Lists of several other new onion services offered by Debian and Tor are available from https://onion.debian.org and https://onion.torproject.org respectively. We expect to expand these lists in the near future to cover even more of Debian's and Tor's services.

Around midnight on August 4th we were notified by a few people that a large number of hidden service addresses have disappeared from the Tor Network. There are a variety of rumors about a hosting company for hidden services: that it is suddenly offline, has been breached, or attackers have placed a javascript exploit on their web site.

A Hidden service is a server – often delivering web pages – that is reachable only through the Tor network. While most people know that the Tor network with its thousands of volunteer-run nodes provides anonymity for users who don´t want to be tracked and identified on the internet, the lesser-known hidden service feature of Tor provides anonymity also for the server operator.

Anyone can run hidden services, and many do. We use them internally at The Tor Project to offer our developers anonymous access to services such as SSH, IRC, HTTP, and our bug tracker. Other organizations run hidden services to protect dissidents, activists, and protect the anonymity of users trying to find help for suicide prevention, domestic violence, and abuse-recovery. Whistleblowers and journalists use hidden services to exchange information in a secure and anonymous way and publish critical information in a way that is not easily traced back to them. The New Yorker's Strongbox is one public example.

Hidden service addresses, aka the dot onion domain, are cryptographically and automatically generated by the tor software. They look like this http://idnxcnkne4qt76tg.onion/, which is our torproject.org website as a hidden service.

There is no central repository nor registry of addresses. The dot onion address is both the name and routing address for the services hosted at the dot onion. The Tor network uses the .onion-address to direct requests to the hidden server and route back the data from the hidden server to the anonymous user. The design of the Tor network ensures that the user can not know where the server is located and the server can not find out the IP-address of the user, except by intentional malicious means like hidden tracking code embedded in the web pages delivered by the server. Additionally, the design of the Tor network, which is run by thousands of volunteers, ensures that it is impossible to censor or block certain .onion-addresses.

The person, or persons, who run Freedom Hosting are in no way affiliated or connected to The Tor Project, Inc., the organization coordinating the development of the Tor software and research. In the past, adversarial organizations have skipped trying to break Tor hidden services and instead attacked the software running at the server behind the dot onion address. Exploits for PHP, Apache, MySQL, and other software are far more common than exploits for Tor. The current news indicates that someone has exploited the software behind Freedom Hosting. From what is known so far, the breach was used to configure the server in a way that it injects some sort of javascript exploit in the web pages delivered to users. This exploit is used to load a malware payload to infect user's computers. The malware payload could be trying to exploit potential bugs in Firefox 17 ESR, on which our Tor Browser is based. We're investigating these bugs and will fix
them if we can.

As for now, one of multiple hidden service hosting companies appears to be down. There are lots of rumors and speculation as to what's happened. We're reading the same news and threads you are and don't have any insider information. We'll keep you updated as details become available.

EDIT: See our next blog post for more details about the attack.

We're excited to announce that a group of students from Wesleyan has created a new TorStatus website written in Python. Their new website is a fine addition to Kasimir Gabert's Tor Network Status page. Kasimir's page is currently the most popular website to learn about running Tor relays.

We're glad that we now have a new Python/Django-based TorStatus, as many developers in the Tor community have been working on complementary Tor Python libraries.

The new TorStatus started out as a rewrite of the old PHP-based TorStatus, so we're building from Kasimir's great ideas. The new TorStatus adds a new landing page, paged results that decrease latency, and carefully crafted graphs with a focus on aesthetics. But it's not only the features that make this code so great. We believe that many more developers will be interested in modifying and extending the codebase! At least that's much simpler now with the move to Python/Django.

The new TorStatus project was done by Norman Danner's students during their summer The Humanitarian Free and Open Source Software at Wesleyan University course. Thanks to Jeremy, Diego, and Vlad for designing, coding, and testing this new TorStatus! Thanks to Damian for co-mentoring the students on Tor's side.

What's next? Want to help out with coding on the new TorStatus? You should start by looking at the codebase and the list of open tickets. Feel free to leave a comment here or drop by #tor-dev if you have suggestions or are interested in helping out!