Anonymous SSH sessions with TOR
Posted by Vincent Wochnik on July 18th, 2009
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Installing TOR
First you should to add the TOR repository to your system. It’s only necessary if there’s no package in the default repositories.
Add the following line to your /etc/apt/sources.list file. You have to replace lenny with your distribution.
deb http://mirror.noreply.org/pub/tor lenny main
To use this repository without problems, you have to add the PGP key to your system.
apt-key adv
--recv-keys--keyserver subkeys.pgp.net 0×94C09C7F
Update your repositories and install TOR.
apt-get update && apt-get install -y tor
If you want to use TOR with OpenSSH, you have to install another program called connect-proxy.
apt-get install -y connect-proxy
Setup OpenSSH to use TOR for all connections
However, this is not recommended, but here is how it works.
Add the following block to the top of your ~/.ssh/config file.
Host *
CheckHostIP no
Comblockquotession yes
Protocol 2
ProxyCommand connect -4 -S localhost:9050 $(tor-resolve %h localhost:9050) %p
The command line syntax won’t change at all.
Setup OpenSSH to use TOR for a specific connection
I recommend using TOR only for a specific connection. All other connections won’t be affected.
Add this block to your ~/.ssh/config. You have to replace mydomain with the host domain name or IP address and myaccount with your user name.
Host mydomain
HostName mydomain.com
User myaccount
CheckHostIP no
Comblockquotession yes
Protocol 2
ProxyCommand connect -4 -S localhost:9050 $(tor-resolve %h localhost:9050) %p
Setup OpenSSH to use TOR for a bunch of connections
Instead of setting up TOR for every single connections, you can do this for a bunch of connections at once. Following example shows how it works.
Host anon_*
CheckHostIP no
Comblockquotession yes
Protocol 2
ProxyCommand connect -4 -S localhost:9050 $(tor-resolve %h localhost:9050) %p
Host anon_mydomain
HostName mydomain.com
User myaccount
Host anon_mydomain2
HostName mydomain2.com
User myaccount
Port 980
This way you know exactly if you’re using TOR or not.
Conclusion
It is very simple to anonymize your SSH sessions if you know what you’re doing. I’ve written this tutorial for legal purposes only. Using this is your own risk.
Copyright (c) Vincent Wochnik 2009
July 19th, 2009 at 9:12 pm
I assume
Comblockquotession yesshould readCompression yesAugust 1st, 2009 at 1:03 pm
Hi,
you could achive the same result and more with iptables. TOR can be used as a transparent proxy. Just bend the connections you want to the transparent proxy. E.g https://wiki.torproject.org/noreply/TheOnionRouter/TransparentProxy