wiki:doc/TorifyHOWTO

Version 235 (modified by trac, 10 years ago) (diff)

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## Copyright (c) 2004 Thomas Sjogren. ## Distributed under the MIT license, ## See ./LegalStuff for a full text ##Original version available at http://www.northernsecurity.net/articles/torify.html [:../:up to Tor]

TORifying software HOWTO

Note that this is a very brief document on how to make various programs use Tor as a proxy; you should read the documentation at freehaven/tor first. Since most programs use similar locations for various settings, the following examples will get you going most of the time. If you're using anything that needs some exotic workarounds, or your distribution doesn't use SysV (/etc/init.d/ startup scripts), for example, this guide currently won't help you a lot, since it is a bit bash and Debian specific. Feel free to edit this page; it's a Wiki, after all.

0. Basic Configuration Issues

0.1 Unix and Linux Configuration

Under Unix and GNU/Linux, most HTTP capable applications, like lynx, wget and curl, will honor the value of the http_proxy environment variable. Some applications use all lower case, some all upper, so specify both to be safe.

Add the following lines to your $HOME/.bash_profile, $HOME/.bashrc, or env settings:

http_proxy=http://127.0.0.1:8118/
HTTP_PROXY=$http_proxy
export http_proxy HTTP_PROXY

Anchor(DNSNote)?

0.2 About DNS and tsocks

tsocks correctly replaces connect(2) calls with calls to your SOCKS proxy (Tor), but it doesn't do anything about requests to your DNS server. This means that if you refer to any machines by hostname when you're using tsocks, you'll be sending that hostname over the network, perhaps leaking the fact that you are about to connect to the corresponding server.

Other applications that use SOCKS 4 or SOCKS 5 directly often have the same shortcoming.

Tor 0.0.8 (or later) has a workaround for this problem; until we can hack tsocks (or a work-alike) to support DNS, instead of using a hostname directly, first use tor-resolve to resolve the hostname into an IP (via Tor) and then use that IP address with your tsocks-ified application.

See [:TheOnionRouter/TorFAQ#SOCKSAndDNS: the FAQ] for more information.

0.3 About socat

socat is a multipurpose relay for bidirectional data transfer. It is possible to use socat as a general means by which programs agnostic of SOCKS can use Tor by connecting to a local TCP port.

Socat (for SOcket CAT) establishes two bidirectional byte streams and transfers data between them. Data channels may be files, pipes, devices (terminal or modem, etc.), or sockets (Unix, IPv4, IPv6, raw, UDP, TCP, SSL). It provides forking, logging and tracing, different modes for interprocess communication and many more options.

It can be used, for example, as a TCP relay (one-shot or daemon), as an external socksifier, as a shell interface to Unix sockets, as an IPv6 relay, as a netcat and rinetd replacement, to redirect TCP-oriented programs to a serial line, or to establish a relatively secure environment (su and chroot) for running client or server shell scripts inside network connections.

What interests us most for Tor is that it supports socks4a redirection, allowing your client to connect to an hidden service. Assuming you want to join to an hidden irc server running on foo.onion on port 6667.

You might want to start a local tunnel that forwards connection for local port 4242 to this service using Tor.

socat TCP4-LISTEN:4242,fork SOCKS4A:localhost:foo.onion:6667,socksport=9050

In this example, connecting to localhost, port 4242, would be equivalent to connecting to foo.onion, port 6667, via Tor.

Warning: socat versions up to and including 1.3.2.2 had a bug that would use SOCKS4A only when a direct DNS resolution attempt failed, thus possibly revealing which DNS names you accessed through socat. See this post tor-dev for details.

1. Web browsers

1.1 Konqueror

Settings -> Configure Konqueror -> Proxy -> Manually Specify the proxy settings -> Setup

HTTP/S Proxy: 127.0.0.1 port 8118

Or edit $HOME/.kde/share/config/kioslaverc:

...
ProxyType=1
...
NoProxyFor=127.0.0.1,localhost
...
httpProxy=http://127.0.0.1:8118
httpsProxy=http://127.0.0.1:8118

Setup -> Network Options

HTTP Proxy:  127.0.0.1 port 8118

Or edit /etc/links.cfg (system-wide) or $HOME/.links/links.cfg (per-user):

...
http_proxy "127.0.0.1:8118"
...

1.3 Lynx

Lynx will respect the http_proxy enviroment variable, but you can edit /etc/lynx.cfg:

...
http_proxy:http://127.0.0.1:8118/
https_proxy:http://127.0.0.1:8118/
...
no_proxy:localhost,127.0.0.1
...

1.4 Mozilla Firefox

Edit -> Preferences -> General -> Connection Settings -> Manual proxy configuration

HTTP Proxy: 127.0.0.1 port 8118
SSL Proxy: 127.0.0.1 port 8118
SOCKS v5

To change the proxy configuration for all Firefox users on your machine, edit the /usr/lib/mozilla-firefox/greprefs/all.js file:

...
pref("network.proxy.type",                  1);
...
pref("network.proxy.http",         "127.0.0.1");
pref("network.proxy.http_port",          8118);
pref("network.proxy.ssl",          "127.0.0.1");
pref("network.proxy.ssl_port",           8118);
pref("network.proxy.socks",                 "");
pref("network.proxy.socks_port",            0);
pref("network.proxy.socks_version",         5);
pref("network.proxy.no_proxies_on",         "localhost, 127.0.0.1");
...

1.5 Wget

Wget will also respect the http_proxy enviroment variable, but you can edit /etc/wgetrc:

...
http_proxy = http://localhost:8118
use_proxy = on
...

2. Email

2.1 Fetchmail

This isn't the most elegant solution, but it works. Rename your /etc/init.d/fetchmail file to {fetchmail-orig, for example, then save the script below as /etc/init.d/fetchmail, and restart fetchmail with /etc/init.d/fetchmail restart. Your mail will now be fetched through the Tor network.

#!/bin/sh
#
# Fetchmail+Tor init script
#

set -e

# Defaults
DAEMON=/usr/bin/tsocks
FMINIT=/etc/init.d/fetchmail-orig
PATH=/sbin:/bin:/usr/sbin:/usr/bin

test -f $DAEMON || exit 0

case "$1" in
	start)
		$DAEMON $FMINIT start	
		;;
	stop)
		$DAEMON $FMINIT stop	
		;;
	force-reload|restart)
		$DAEMON $FMINIT restart
		;;
	try-restart)
		$DAEMON $FMINIT try-restart
		;;
	awaken)
		$DAEMON $FMINIT awaken
		;;
	debug-run)
		$DAEMON $FMINIT debug-run
		;;
	*)
		echo "Usage: /etc/init.d/fetchmail {start|stop|restart|force-reload|awaken|debug-run}"
		echo "  start - starts system-wide fetchmail service"
		echo "  stop  - stops system-wide fetchmail service"
		echo "  restart, force-reload - starts a new system-wide fetchmail service"
		echo "  awaken - tell system-wide fetchmail to start a poll cycle immediately"
		echo "  debug-run [strace [strace options...]] - start a debug run of the"
		echo "    system-wide fetchmail service, optionally running it under strace"
		exit 1
		;;
esac

exit 0

An alternative configuration for fetchmail for those that prefer to start it on a per-user basis. Add the following to the user's .bashrc:

CONF_FILE="$HOME/.fetchmailrc"
PID_FILE="$HOME/.fetchmail.pid"
FETCHMAIL="/usr/bin/fetchmail"
TSOCKS="/usr/bin/tsocks"

  function FetchMailAlive () {
    if test -f $CONF_FILE && test -f $FETCHMAIL; then  
      if test -f $PID_FILE; then 
        if ! kill -0 `cut -d \  -f1 $PID_FILE` 2>/dev/null; then
          eval $($TSOCKS $FETCHMAIL)
          echo New FetchMail started. >&2
        fi
      else   
        eval $($TSOCKS $FETCHMAIL)
        echo New FetchMail started. >&2
      fi
    else
      echo Fetchmail not installed or configured properly. >&2
    fi
  }

# Call it
FetchMailAlive

Then it checks for a running fetchmail daemon every time a new shell is opened and starts one if needed.

You may want to look up your mail server's IP with tor-resolve and use the IP in place of a hostname; see the note on tsocks and DNS above.

3. Instant messaging

3.1 Gaim

Preferences -> Network -> Proxy

Proxy type: Socks 5
Host: 127.0.0.1
Port: 9050

See the note on tsocks and DNS above.

3.2 Psi

Psi is a Jabber client with support for additional Jabber JEP-0027 encryption, with GnuPG and Socks 5 proxy support.

Account Setup -> Modify -> Connection -> Proxy -> Edit -> New

Properties:
Name: Tor
Type: SOCKS Version 5
Settings:
Host: 127.0.0.1
Port: 9050

See the note on tsocks and DNS above.

4. IRC/SILC

4.1 Irssi

Run Irssi with tsocks irssi. Unfortunately, Irssi's own proxy configuration options are HTTP specific.

For Gentoo and Debian users: torify irssi

You may want to look up your IRC server's IP with tor-resolve and use the IP in place of a hostname; see the [:#DNSNote: note on tsocks and DNS] above.

4.2 X-Chat

Settings-> Preferences -> Network -> Network setup -> Proxy server

Hostname: 127.0.0.1
Port: 9050
Type: Socks5 

See the note on tsocks and DNS above.

4.3 SILC

Since the SILC client is based on Irssi, you can follow the same procedure to make it use Tor. Combining Tor and SILC might be one of the safest ways to communicate with someone over the Internet. More information about SILC is available at its website.

4.4 BitchX

In order to use BitchX with tor, you first need to get ProxyChains, a *NIX-only HTTP and SOCKS proxy client. On Debian systems, install the proxychains package. Once installed, just add

socks5 127.0.0.1 9050
http localhost 8118

to the ProxyChains config file at ~/.proxychains/proxychains.conf. Now that it is configured, type proxychains bitchx at the command line.

The gentoo build of proxychains seems to be broken on x86 arch. Using tsocks BitchX or torify BitchX works well.

You may want to look up your IRC server's IP with tor-resolve and use the IP in place of a hostname; see the note on tsocks and DNS above.

5. BitTorrent

Same procedure as with BitchX, but using proxychains btdownloadcurses.

5.1 Azureus

See http://azureus.sourceforge.net/doc/AnonBT/.

6. Misc

6.1 GnuPG

Add or edit the following lines in your $HOME/.gnupg/gpg.conf:

keyserver x-hkp://yod73zr3y6wnm2sw.onion
keyserver-options honor-http-proxy broken-http-proxy

You may obviously use any public keyserver, like subkeys.pgp.net, but hidden services are preferred. At the time of this writing. only two key servers running as hidden servers are publicly available -- d3ettcpzlta6azsm.onion/ and yod73zr3y6wnm2sw.onion.

After that is done, just run

export http_proxy=http://127.0.0.1:8118/
gpg --refresh-keys

If you don't want to write the export line every time, you can add alias gpg='http_proxy=http://127.0.0.1:8118/ gpg' to your .bashrc file as well; if you have set the http_proxy environment variable, you may skip this step.

6.2 SSH --via--> Tor with connect

Method 1 - These instructions should work on most *nix systems. Tested on Mac OS X 10.3.x and Debian GNU/Linux.

1 - Upgrade your SSH to an OpenSSH version that has Socks 5 support. The OpenSSH client that is shipped with Mac OS X 10.3 (aka Panther) - OpenSSH_3.6.1p1 - will not work correctly. Download, build and install the current stable version from the OpenSSH website. If you're using Mac OS X, using fink may be easier for you.

2 - Download and build the connect source code. Connect will allow socket connections using SOCKS4/5 and HTTP tunnels. For detailed information on connect, please visit its website.

A pre-compiled version of connect for Mac OS X is available here. (md5sum: b5180cb789813fc958209c58b99039fa)

Install connect into the /usr/local/bin directory.

3 - Add the following line to your ssh_config file located at: /etc/ssh/ssh_config (system-wide) or $HOME/.ssh/config (on a per-user basis).

If you used fink to install OpenSSH, it is located at /sw/etc/ssh/ssh_config.

ProxyCommand /usr/local/bin/connect -4 -S 127.0.0.1:9050 %h %p

All SSH connections will now go through tor.

You may want to look up your SSH server's IP with tor-resolve and use the IP in place of a hostname; see the note on tsocks and DNS above.

Credits

Thomas Sjogren with Northern Security started this howto and still maintains a copy at:

http://www.northernsecurity.net/articles/torify.html

Other Contributing Authors:

  • Dave Vehrs
  • Nick Mathewson
  • Thomas Hardly