# Configure Obfs4 proxy with tor

I used obfs3 as socks proxy with Openvpn and it was very easy to configure and operate.

I want to use obfs4 proxy. I am running Ubuntu 14.10, i have installed latest tor package version (Tor version 0.2.7.6 (git-605ae665009853bd)). and latest obfs4proxy version (obfs4proxy-0.0.4).

Server configuration as described in obfs4 docs and from this tor answer:

# /etc/tor/torrc in server

RunAsDaemon 1
ORPort 9001
BridgeRelay 1
ServerTransportPlugin obfs4 exec /usr/bin/obfs4proxy
ExtORPort auto


Client configurations:

# /etc/tor/torrc in client
ClientTransportPlugin obfs4 exec /usr/bin/obfs4proxy


In obfs3, i could add --dest to server and add proxy {ip:port} on client. I cannot find this arguments any more on obfs4. How could i make Openvpn use tor with obfs4 as a proxy?

Also i noticed that when i stop tor service, obfs4proxy executable don't be terminated, and from the log on /var/log/tor/log I found these lines

Jul 21 12:39:27.000 [notice] Interrupt: exiting cleanly.
Jul 21 12:39:27.000 [notice] Failed to terminate process with PID '11673' ('Permission denied').


Note: The process with PID '11673' is the obfs4proxy process.

• Did you install it as an Ubuntu package (from which package source) or from source? Could you add --enableLogging as option to your obfs4proxy call? This will probably give you a more detailed output. However the log line you posted tells that some permissions are wrong. Please check the permissions of your directories. – Jens Kubieziel Aug 4 '16 at 12:58

You probably want to have a read through the Pluggable Transport specification, they're controlled and configured through environment variables. You'll need to set them appropriately to get it to work with OpenVPN. Note that obfs4 also requires the client to have a "certificate" to be able to connect.

I'm unsure why tor cannot terminate obfs4, maybe you've assigned it capabilities or made it setuid, we need more information.

Also Ubuntu 14.10 is dead and you should no longer be running it for anything, you won't get security updates, see: "Ubuntu 14.10 (Utopic Unicorn) End of Life reached on July 23, 2015".