This is an update of the initial blog post on running rust-libp2p traffic over the Tor network. In that post we used the torut library to configure the tor onion service in code. Turns out, for some use cases, there is a more simple method. This post runs through that method.
I have created and hosted on
crate that implements a
libp2p transport, for this post I’ll be referencing code in the
repository backing that crate and also the examples directory of that
Basic networked application in Rust using libp2p
directory contains a module called
ping that implements the ping
server as we did in the first blog post, copying code from the
rust-libp2p ping example.
Configuring Tor via the runcom file
What I would like to discuss is how we configure the onion service
(formally hidden service). In v1 of this post we used torut to do so.
I have since discovered that by simple adding a few lines to the tor
runcom file (e.g.
/etc/tor/torcr) we can configure the onion service
and simplify considerably the usage of our tor transport. To the
config file we can un-comment/add the following lines:
HiddenServiceDir /var/lib/tor/hidden_service/ HiddenServicePort 7 127.0.0.1:7777
Once tor runs it will store the onion address for the service we just configured in the hidden service directory given i.e.,
cat /var/lib/tor/hidden_service/hostname 7gr3dngwhk74thi4vv6bm3v3bicaxe4apvcemoxo3hadpvsyfifjqnid.onion
We pass this address to the swarm’s dial method as one would expect to with any other multi address.
The final piece of magic that we need to provide is a mapping of onion
addresses to local port numbers. This allows the listen side of the
transport to create a TCP socket and bind it to the port that Tor is
expecting. In the above example the local process listens on port 7777
so when we call
listen_on with the onion address above this onion
address is mapped to port 7777.
BOOM! That’s it, the
Socks5TokioTcpConfig type takes care of
everything else for us and we are away - anonymous peer to peer
applications in Rust using rust-libp2p over Tor!
Thanks for reading,