Difference between revisions of "Tor"

Revision as of 04:27, 9 September 2013

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Tor is an open source implementation of 2nd generation onion routing that provides free access to an anonymous proxy network. Its primary goal is to enable online anonymity by protecting against traffic analysis attacks.

Introduction

Users of the Tor network run an onion proxy on their machine. This software connects out to Tor, periodically negotiating a virtual circuit through the Tor network. Tor employs cryptography in a layered manner (hence the 'onion' analogy), ensuring perfect forward secrecy between routers. At the same time, the onion proxy software presents a SOCKS interface to its clients. SOCKS-aware applications may be pointed at Tor, which then multiplexes the traffic through a Tor virtual circuit.

Warning: Tor by itself is not all you need to maintain your anonymity. There are several major pitfalls to watch out for (see: Want Tor to really work?).

Through this process the onion proxy manages networking traffic for end-user anonymity. It keeps a user anonymous by encrypting traffic, sending it through other nodes of the Tor network, and decrypting it at the last node to receive your traffic before forwarding it to the server you specified. One trade off that has to be made for the anonymity Tor provides is that it can be considerably slower than a regular direct connection, due to the large amount of traffic re-routing. Additionally, although Tor provides protection against traffic analysis it cannot prevent traffic confirmation at the boundaries of the Tor network (i.e. the traffic entering and exiting the network).

Template:Wikipedia

Installation

Install tor, available in the official repositories.

Additionally, there is a Qt frontend for Tor in package vidalia. In addition to controlling the Tor process, Vidalia allows you to view and configure the status of Tor, monitor bandwidth usage, and view, filter, and search log messages.

Configuration

To get a better understanding of Tor review the /etc/tor/torrc configuration file. The configuration options are explained in man tor and the Tor website. The default configuration should work fine for most Tor users.

You can set custom file descriptor ulimits for Tor in /etc/conf.d/tor using the TOR_MAX_FD variable. This sets a limit on the maximum number of open files.

By default Tor logs to stdout with a log-level of "notice". If system logging is enabled in the torrc configuration file, it will default to /usr/local/var/log/tor/.

The "RunAsDaemon" setting conflicts with the default runtype of "simple" in the service file. You should not need to enable it. systemd handles the daemonization of tor. If you do enable it for whatever reason, you will need to override the service file to change the runtype to "Type=forking" so systemd allows tor to fork itself.

Running Tor in a Chroot

For security purposes, it may be desirable to run Tor in a chroot. The following script will create an appropriate chroot in /opt/torchroot:

~/torchroot-setup.sh

#!/bin/bash
export TORCHROOT=/opt/torchroot

mkdir -p $TORCHROOT
mkdir -p $TORCHROOT/etc/tor
mkdir -p $TORCHROOT/dev
mkdir -p $TORCHROOT/usr/bin
mkdir -p $TORCHROOT/usr/lib
mkdir -p $TORCHROOT/var/lib

ln -s /usr/lib  $TORCHROOT/lib
cp /etc/hosts           $TORCHROOT/etc/
cp /etc/host.conf       $TORCHROOT/etc/
cp /etc/localtime       $TORCHROOT/etc/
cp /etc/nsswitch.conf   $TORCHROOT/etc/
cp /etc/resolv.conf     $TORCHROOT/etc/
cp /etc/tor/torrc       $TORCHROOT/etc/tor/

cp /usr/bin/tor         $TORCHROOT/usr/bin/
cp /lib/libnss* /lib/libnsl* /lib/ld-linux.so* /lib/libresolv* /lib/libgcc_s.so* $TORCHROOT/usr/lib/
cp $(ldd /usr/bin/tor | awk '{print $3}'|grep --color=never "^/") $TORCHROOT/usr/lib/
cp -r /var/lib/tor      $TORCHROOT/var/lib/
chown -R tor:tor $TORCHROOT/var/lib/tor

sh -c "grep --color=never ^tor /etc/passwd > $TORCHROOT/etc/passwd"
sh -c "grep --color=never ^tor /etc/group > $TORCHROOT/etc/group"

mknod -m 644 $TORCHROOT/dev/random c 1 8
mknod -m 644 $TORCHROOT/dev/urandom c 1 9
mknod -m 666 $TORCHROOT/dev/null c 1 3

if [[ "$(uname -m)" == "x86_64" ]]; then
  cp /usr/lib/ld-linux-x86-64.so* $TORCHROOT/usr/lib/.
  ln -s /usr/lib64 $TORCHROOT/lib64
  ln -s $TORCHROOT/usr/lib ${TORCHROOT}/usr/lib64
fi

After running the script as root, Tor can be launched in the chroot with the command: # chroot --userspec=tor:tor /opt/torchroot /usr/bin/tor

Usage

Start tor daemon from command line. Enable systemd service if you wish to have it running since boot.

Alternatively, you can launch it from the vidalia interface.

To use a program over tor, configure it to use 127.0.0.1 or localhost as a SOCKS5 proxy, with port 9050 (plain tor with standard settings) or port 9051 (configuration with vidalia, standard settings). To check if Tor is functioning properly visit the Tor, Harvard or Xenobite.eu websites.

Web browsing

The Tor Project currently only supports web browsing with tor through the Tor Browser Bundle, which can be downloaded from the AUR (tor-browser-en^AUR). It is built with a patched version of the Firefox extended support releases. Tor can also be used with regular Firefox, Chromium and other browsers, but this is not recommended by the Tor Project.

Tip: For makepkg to verify the signature on the AUR source tarball download for TBB, signing keys from the Tor Project (currently 0x63FEE659) must be downloaded from the keyservers and added to the user gpg keyring with:

$ gpg --recv-keys 0x63FEE659

Firefox

In Preferences > Advanced > Network tab > Settings manually set Firefox to use the SOCKS proxy localhost with port 9050. Then you must type about:config into the address bar and void your warranty. Change network.proxy.socks_remote_dns to true and restart the browser. This channels all DNS requests through TOR's socks proxy.

Chromium

You can simply run:

$ chromium --proxy-server="socks://localhost:9050"

Just as with Firefox, you can setup a fast switch for example through Proxy SwitchySharp.

Once installed enter in its configuration page. Under the tab Proxy Profiles add a new profile Tor, if ticked untick the option Use the same proxy server for all protocols, then add localhost as SOCKS Host, 9050 to the respective port and select SOCKS v5.

Optionally you can enable the quick switch under the General tab to be able to switch beetween normal navigation and Tor network just by left-clicking on the Proxy SwitchySharp's icon.

Luakit

You can simply run:

$ torify luakit

HTTP proxy

Tor can be used with an HTTP proxy like Polipo or Privoxy, however the Tor dev team recommends using the SOCKS5 library since browsers directly support it.

Firefox

The FoxyProxy add-on allows you to specify multiple proxies for different URLs or for all your browsing. After restarting Firefox manually set Firefox to port 8118 on localhost, which is where Polipo or Privoxy are running. These settings can be access under Add > Standard proxy type. Select a proxy label (e.g Tor) and enter the port and host into the HTTP Proxy and SSL Proxy fields. To check if Tor is functioning properly visit the Tor Check website and toggle Tor.

Polipo

The Tor Project has created a custom Polipo configuration file to prevent potential problems with Polipo as well to provide better anonymity.

Keep in mind that Polipo is not required if you can use a SOCKS 5 proxy, which Tor starts automatically on port 9050. If you want to use Chromium with Tor, you do not need the Polipo package (see: #Chromium).

Privoxy

You can also use this setup in other applications like messaging (e.g. Jabber, IRC). Applications that support HTTP proxies you can connect to Privoxy (i.e. 127.0.0.1:8118). To use SOCKS proxy directly, you can point your application at Tor (i.e. 127.0.0.1:9050). A problem with this method though is that applications doing DNS resolves by themselves may leak information. Consider using Socks4A (e.g. with Privoxy) instead.

Instant messaging

In order to use an IM client with tor, we do not need an http proxy like polipo/privoxy. We will be using tor's daemon directly which listens to port 9050 by default.

Pidgin

You can set up Pidgin to use Tor globally, or per account. To use Tor globally, go to Tools -> Preferences -> Proxy. To use Tor for specific accounts, go to Accounts > Manage Accounts, select the desired account, click Modify, then go to the Proxy tab. The proxy settings are as follows:

Proxy type 	SOCKS5
Host 	        127.0.0.1
Port 	        9150

Note that some time in 2013 the Port has changed from 9050 to 9150 if you use the Tor Browser Bundle. Try the other value if you receive a "Connection refused" message.

Irssi

Freenode does not recommend that you use Privoxy with Irssi. Instead they recommend using the mapaddress approach and running torify irssi to start it up. Therefore, add the following to /etc/tor/torrc:

mapaddress  10.40.40.40 p4fsi4ockecnea7l.onion

Freenode requires charybdis and ircd-seven's SASL mechanism for identifying to nickserv during connection. Download cap_sasl.pl, which enables SASL in Irssi, from the Freenode website (i.e. http://www.freenode.net/sasl/cap_sasl.pl) and save it to ~/.irssi/scripts/cap_sasl.pl

Then install perl-crypt-openssl-bignum, perl-crypt-blowfish and then perl-crypt-dh^AUR from the AUR.

Alternatively, you can install the modules using perl:

$ perl -MCPAN -e 'install Crypt::OpenSSL::Bignum Crypt::DH Crypt::Blowfish'

Start irssi

$ torify irssi

Load the script that will employ the SASL mechanism.

/script load cap_sasl.pl

Set your identification to nickserv, which will be read when connecting. Supported mechanisms are PLAIN and DH-BLOWFISH.

/sasl set network username password mechanism

Connect to Freenode:

/connect -network network 10.40.40.40

For more information check Accessing freenode Via Tor and the SASL README at freenode.net or the IRC/SILC Wiki article at torproject.org.

If you are receiving errors check the Cannot Connect to Freenode IRC using Irssi & Tor thread on the Arch Linux forums.

Pacman

Pacman download operations (repository DBs, packages, and public keys) can be done using the Tor network. Though relatively extreme, this measure is useful to prevent an adversary (most likely at one's LAN or the mirror) from knowing a subset of the packages you have installed, at the cost of longer latency, lower throughput, possible suspicion, and possible failure (if Tor is being filtered via the current connection).

Warning: It would be arguably simpler for an adversary, specifically one who desires to indiscriminately disseminate malware, to perform his/her activity by deploying malicious Tor exit node(s). Always use signed packages and verify new public keys by out-of-band means.

/etc/pacman.conf

...
XferCommand = /usr/bin/curl --socks5-hostname localhost:9050 -C - -f %u > %o
...

Running a Tor server

The Tor network is reliant on people contributing bandwidth. There are several ways to contribute to the network.

Running a Tor bridge

This involves making your machine an 'entry node' for people who are having trouble connecting to Tor through traditional methods.

Configuration

According to https://www.torproject.org/docs/bridges , make your torrc be just these four lines:

   SocksPort 0
   ORPort 443
   BridgeRelay 1
   Exitpolicy reject *:*

Troubleshooting

If you get "Could not bind to 0.0.0.0:443: Permission denied" errors on startup, you'll need to pick a higher ORPort (e.g. 8080), or perhaps forward the port in your router.

Running a "Middleman" relay

This means that your machine will contribute bandwidth to the 'internal' part of the network, acting as neither an entry nor exit point, merely forwarding bits to and from other Tor nodes/relays.

Configuration

You should at least share 20KiB/s:

Nickname tornickname
ORPort 9001
BandwidthRate 20 KB            # Throttle traffic to 20KB/s
BandwidthBurst 50 KB           # But allow bursts up to 50KB/s

Run Tor as middleman ( a relay):

ExitPolicy reject *:*

Running a Tor exit node

Any requests from a Tor user to the regular internet obviously need to exit the network somewhere, and exit nodes provide this vital service. To the accessed host, the request will appear as having originated from your machine. This means that running an exit node is generally considered more legally onerous than running other forms of Tor relays. Before becoming an exit relay, you may want to read Tips for Running an Exit Node With Minimal Harrasment.

Configuration

Using the torrc, you can configure which services you wish to allow through your exit node. Allow all traffic:

ExitPolicy accept	*:*

Allow only irc ports 6660-6667 to exit from node:

ExitPolicy accept *:6660-6667,reject *:* # Allow irc ports but no more

By default, Tor will block certain ports. You can use the torrc to overide this.

ExitPolicy accept *:119        # Accept nntp as well as default exit policy

TorDNS

The Tor 0.2.x series provides a built-in DNS forwarder. To enable it add the following lines to the Tor configuration file and restart the daemon:

/etc/tor/torrc

 DNSPort 9053
 AutomapHostsOnResolve 1
 AutomapHostsSuffixes .exit,.onion

This will allow Tor to accept DNS requests (listening on port 9053 in this example) like a regular DNS server, and resolve the domain via the Tor network. A downside is that it's only able to resolve DNS queries for A-records; MX and NS queries are never answered. For more information see this Debian-based introduction.

DNS queries can also be performed through a command line interface by using tor-resolve. For example:

$ tor-resolve archlinux.org
66.211.214.131

Using TorDNS for all DNS queries

It is possible to configure your system, if so desired, to use TorDNS for all queries your system makes, regardless of whether or not you eventually use Tor to connect to your final destination. To do this, configure your system to use 127.0.0.1 as its DNS server and edit the 'DNSPort' line in /etc/tor/torrc to show:

DNSPort 53

Alternatively, you can use a local caching DNS server, such as dnsmasq or pdnsd, which will also compensate for TorDNS being a little slower than traditional DNS servers. The following instructions will show how to set up dnsmasq for this purpose.

Change the tor setting to listen for the DNS request in port 9053 and install dnsmasq.

Modify its configuration file so that it contains:

/etc/dnsmasq.conf

 no-resolv
 server=127.0.0.1#9053
 listen-address=127.0.0.1

These configurations set dnsmasq to listen only for requests from the local computer, and to use TorDNS at its sole upstream provider. It is now neccessary to edit /etc/resolv.conf so that your system will query only the dnsmasq server.

/etc/resolv.conf

 nameserver 127.0.0.1

Start the dnsmasq daemon.

Finally if you use dhcpd you would need to change its settings to that it does not alter the resolv configuration file. Just add this line in the configuration file:

/etc/dhcpcd.conf

 nohook resolv.conf

If you already have an nohook line, just add resolv.conf separated with a comma.

Torify

torify will allow you use an application via the Tor network without the need to make configuration changes to the application involved. From the man page:

torify is a simple wrapper that calls tsocks with a tor specific configuration file. tsocks itself is a wrapper between the tsocks library and the application that you would like to run socksified

Usage example:

$ torify elinks checkip.dyndns.org
$ torify wget -qO- https://check.torproject.org/ | grep -i congratulations

Torify will not, however, perform DNS lookups through the Tor network. A workaround is to use it in conjunction with tor-resolve (described above). In this case, the procedure for the first of the above examples would look like this:

$ tor-resolve checkip.dyndns.org

208.78.69.70

$ torify elinks 208.78.69.70

Troubleshooting

Problem with user value

If the tor daemon failed to start, then run the following command as root (or use sudo)

# tor

If you get the following error

May 23 00:27:24.624 [warn] Error setting groups to gid 43: "Operation not permitted".
May 23 00:27:24.624 [warn] If you set the "User" option, you must start Tor as root.
May 23 00:27:24.624 [warn] Failed to parse/validate config: Problem with User value. See logs for details.
May 23 00:27:24.624 [err] Reading config failed--see warnings above.

Then it means that the problem is with the User value, which likely means that one or more files or directories in your /var/lib/tor directory is not owned by tor. This can be determined by using the following find command:

find /var/lib/tor/ ! -user tor

Any files or directories listed in the output from this command needs to have its ownership changed. This can be done individually for each file like so:

chown tor:tor /var/lib/tor/filename

Or to change everything listed by the above find example, modify the command to this:

find /var/lib/tor/ ! -user tor -exec chown tor:tor {} \;

Tor should now start up correctly.

Still if you cannot start the tor service, run the service using root (this will switch back to the tor user). To do this, change the user name in the /etc/tor/torrc file:

User tor

Now modify the systemd's tor service file /usr/lib/systemd/system/tor.service as follows

[Service]
User=root
Group=root
Type=simple

The process will be run as tor user. For this purpose change user and group ID to tor and also make it writable:

# chown -R tor:tor /var/lib/tor/
# chmod -R 755 /var/lib/tor

Now save changes and run the daemon:

# systemctl --system daemon-reload
# systemctl start tor.service

Daemon fails on restart

This article or section is out of date.

Reason: rc.d? (Discuss in Talk:Tor#)

If after issuing a daemon restart you have log entries similar to

Interrupt: we have stopped accepting new connections, and will shut down in 30 seconds. Interrupt again to exit now

and the daemon fails to start back up, a simple workaround is to open /etc/rc.d/tor in your favourite editor and increase the time waited between the shutting down and starting up again of the daemon. For example:

/etc/rc.d/tor

    ;;
  restart)
    $0 stop
    sleep 35
    $0 start
    ;;

This will allow Tor to shutdown cleanly, and restart after a safe period of time. Remember that this file may be overwritten by upgrades.

@@ Line 1: / Line 1: @@
 [[Category:Internet Applications]]
 [[Category:Proxy servers]]
-[[Category:Daemons and system services]]
 [[es:Tor]]
 [[ru:Tor]]
@@ Line 13: / Line 12: @@
 {{Article summary heading|Related}}
 {{Article summary wiki|Gnunet}}
+{{Article summary wiki|I2P}}
+{{Article summary wiki|Freenet}}
 {{Article summary end}}
 '''Tor''' is an open source implementation of 2nd generation [[Wikipedia:Onion routing|onion routing]] that provides free access to an anonymous proxy network. Its primary goal is to enable [[Wikipedia:internet anonymity|online anonymity]] by protecting against [[Wikipedia:Traffic analysis|traffic analysis]] attacks.
-==Introduction==
+== Introduction ==
 Users of the Tor network run an onion proxy on their machine. This software connects out to Tor, periodically negotiating a virtual circuit through the Tor network. Tor employs cryptography in a layered manner (hence the 'onion' analogy), ensuring perfect forward secrecy between routers. At the same time, the onion proxy software presents a SOCKS interface to its clients. SOCKS-aware applications may be pointed at Tor, which then multiplexes the traffic through a Tor virtual circuit.
@@ Line 26: / Line 28: @@
 {{Wikipedia|Tor (anonymity network)}}
-==Installation==
+== Installation ==
 [[pacman|Install]] {{Pkg|tor}}, available in the [[official repositories]].
 Additionally, there is a [[Qt]] frontend for Tor in package {{Pkg|vidalia}}. In addition to controlling the Tor process, Vidalia allows you to view and configure the status of Tor, monitor bandwidth usage, and view, filter, and search log messages.
-==Configuration==
+== Configuration ==
 To get a better understanding of Tor review the {{ic|/etc/tor/torrc}} configuration file. The configuration options are explained in {{Ic|man tor}} and the [https://torproject.org/docs/tor-manual.html.en Tor website]. The default configuration should work fine for most Tor users.
@@ Line 38: / Line 42: @@
 By default Tor logs to [[Wikipedia:Stdout#Standard output (stdout)|stdout]] with a log-level of "notice". If system logging is enabled in the {{ic|torrc}} configuration file, it will default to {{Ic|/usr/local/var/log/tor/}}.
-==Usage==
+The "RunAsDaemon" setting conflicts with the default runtype of "simple" in the service file. You should not need to enable it. systemd handles the daemonization of tor. If you do enable it for whatever reason, you will need to override the service file to change the runtype to "Type=forking" so systemd allows tor to fork itself.
+== Running Tor in a Chroot ==
+For security purposes, it may be desirable to run Tor in a [[chroot]]. The following script will create an appropriate chroot in /opt/torchroot:
+{{hc|~/torchroot-setup.sh|2=<nowiki>
+#!/bin/bash
+export TORCHROOT=/opt/torchroot
+mkdir -p $TORCHROOT
+mkdir -p $TORCHROOT/etc/tor
+mkdir -p $TORCHROOT/dev
+mkdir -p $TORCHROOT/usr/bin
+mkdir -p $TORCHROOT/usr/lib
+mkdir -p $TORCHROOT/var/lib
+ln -s /usr/lib  $TORCHROOT/lib
+cp /etc/hosts           $TORCHROOT/etc/
+cp /etc/host.conf       $TORCHROOT/etc/
+cp /etc/localtime       $TORCHROOT/etc/
+cp /etc/nsswitch.conf   $TORCHROOT/etc/
+cp /etc/resolv.conf     $TORCHROOT/etc/
+cp /etc/tor/torrc       $TORCHROOT/etc/tor/
+cp /usr/bin/tor         $TORCHROOT/usr/bin/
+cp /lib/libnss* /lib/libnsl* /lib/ld-linux.so* /lib/libresolv* /lib/libgcc_s.so* $TORCHROOT/usr/lib/
+cp $(ldd /usr/bin/tor | awk '{print $3}'|grep --color=never "^/") $TORCHROOT/usr/lib/
+cp -r /var/lib/tor      $TORCHROOT/var/lib/
+chown -R tor:tor $TORCHROOT/var/lib/tor
+sh -c "grep --color=never ^tor /etc/passwd > $TORCHROOT/etc/passwd"
+sh -c "grep --color=never ^tor /etc/group > $TORCHROOT/etc/group"
+mknod -m 644 $TORCHROOT/dev/random c 1 8
+mknod -m 644 $TORCHROOT/dev/urandom c 1 9
+mknod -m 666 $TORCHROOT/dev/null c 1 3
-Tor runs as a [[daemon]]. To launch it, use:
+if [[ "$(uname -m)" == "x86_64" ]]; then
+  cp /usr/lib/ld-linux-x86-64.so* $TORCHROOT/usr/lib/.
+  ln -s /usr/lib64 $TORCHROOT/lib64
+  ln -s $TORCHROOT/usr/lib ${TORCHROOT}/usr/lib64
+fi
-'''SysV'''
+</nowiki>}}
- /etc/rc.d/tor start
-(add it to the {{ic|DAEMONS}} array to have it launch at startup)
-'''systemd'''
+After running the script as root, Tor can be launched in the [[chroot]] with the command: {{ic|# chroot --userspec&#61;tor:tor /opt/torchroot /usr/bin/tor}}
- systemctl start tor
-(use ''systemctl enable tor'' to have it launch at startup)
+== Usage ==
+Start '''tor''' [[daemon]] from command line. Enable [[systemd]] service if you wish to have it running since boot.
 Alternatively, you can launch it from the vidalia interface.
@@ Line 55: / Line 98: @@
 To check if Tor is functioning properly visit the [https://check.torproject.org/ Tor],  [http://serifos.eecs.harvard.edu/cgi-bin/ipaddr.pl?tor=1 Harvard] or [https://torcheck.xenobite.eu/ Xenobite.eu] websites.
-==Web browsing==
+== Web browsing ==
-Tor primarily supports [[Firefox]], but can also be used with [[Chromium]] and other browsers.
+The Tor Project currently only supports web browsing with tor through the Tor Browser Bundle, which can be downloaded from the AUR ({{aur|tor-browser-en}}). It is built with a patched version of the Firefox extended support releases. Tor can also be used with regular [[Firefox]], [[Chromium]] and other browsers, but this is [https://www.torproject.org/docs/faq.html.en#TBBOtherBrowser not recommended] by the Tor Project.
+{{Tip|For makepkg to verify the signature on the AUR source tarball download for TBB, [https://www.torproject.org/docs/signing-keys.html.en signing keys from the Tor Project] (currently 0x63FEE659) must be downloaded from the keyservers and added to the user gpg keyring with:
+ $ gpg --recv-keys 0x63FEE659
+}}
+=== Firefox ===
-===Firefox===
+In ''Preferences > Advanced > Network tab > Settings'' manually set Firefox to use the SOCKS proxy {{ic|localhost}} with port {{ic|9050}}. Then you must type {{ic|about:config}} into the address bar and ''void your warranty''. Change {{ic|network.proxy.socks_remote_dns}} to {{ic|true}} and restart the browser. This channels all DNS requests through TOR's socks proxy.
-In ''Preferences > Advanced > Network tab > Settings'' manually set Firefox to use the SOCKS proxy {{ic|localhost}} with port {{ic|9050}}.
-Alternatively, install the Tor Browser Bundle (i.e. {{aur|tor-browser-en}}). This will allow you to toggle very easily between Tor navigation and normal navigation instead of changing the preferences.
+=== Chromium ===
-===Chromium===
 You can simply run:
   $ chromium --proxy-server="socks://localhost:9050"
-As for Firefox you can setup a fast switch for example through [https://chrome.google.com/webstore/detail/dpplabbmogkhghncfbfdeeokoefdjegm Proxy SwitchySharp].
+Just as with Firefox, you can setup a fast switch for example through [https://chrome.google.com/webstore/detail/dpplabbmogkhghncfbfdeeokoefdjegm Proxy SwitchySharp].
 Once installed enter in its configuration page. Under the tab ''Proxy Profiles'' add a new profile ''Tor'', if ticked untick the option ''Use the same proxy server for all protocols'', then add ''localhost'' as SOCKS Host, ''9050'' to the respective port and select ''SOCKS v5''.
@@ Line 73: / Line 121: @@
 Optionally you can enable the quick switch under the ''General'' tab to be able to switch beetween normal navigation and Tor network just by left-clicking on the Proxy SwitchySharp's icon.
-==HTTP Proxy==
+=== Luakit ===
-Tor can be used with an HTTP proxy like [[Polipo]] or [[Privoxy]].
-{{note|Polipo is recommended over Privoxy by the Tor dev team. [https://trac.torproject.org/projects/tor/wiki/doc/TorFAQ#WhydoweneedPolipoorPrivoxywithTorWhichisbetter]}}
+You can simply run:
+ $ torify luakit
+== HTTP proxy ==
+Tor can be used with an HTTP proxy like [[Polipo]] or [[Privoxy]], however the Tor dev team recommends using the SOCKS5 library since browsers directly support it.
+=== Firefox ===
-===Firefox===
 The [https://addons.mozilla.org/en-us/firefox/addon/foxyproxy-standard/ FoxyProxy] add-on  allows you to specify multiple proxies for different URLs or for all your browsing. After restarting Firefox manually set Firefox to port {{ic|8118}} on {{ic|localhost}}, which is where [[Polipo]] or [[Privoxy]] are running. These settings can be access under ''Add > Standard proxy type''. Select a proxy label (e.g Tor) and enter the port and host into the ''HTTP Proxy'' and ''SSL Proxy'' fields. To check if Tor is functioning properly visit the [https://check.torproject.org/ Tor Check] website and toggle Tor.
-===Polipo===
+=== Polipo ===
 The Tor Project has created a custom [https://gitweb.torproject.org/torbrowser.git/blob_plain/HEAD:/build-scripts/config/polipo.conf Polipo configuration file] to prevent potential problems with Polipo as well to provide better anonymity.
 Keep in mind that Polipo is not required if you can use a SOCKS 5 proxy, which Tor starts automatically on port 9050. If you want to use [[Chromium]] with Tor, you do not need the Polipo package (see: [[#Chromium]]).
-===Privoxy===
+=== Privoxy ===
 You can also use this setup in other applications like messaging (e.g. Jabber, IRC). Applications that support HTTP proxies you can connect to Privoxy (i.e. {{ic|127.0.0.1:8118}}). To use SOCKS proxy directly, you can point your application at Tor (i.e. {{ic|127.0.0.1:9050}}). A problem with this method though is that applications doing DNS resolves by themselves may leak information. Consider using Socks4A (e.g. with Privoxy) instead.
-==Instant Messaging==
+== Instant messaging ==
 In order to use an IM client with tor, we do not need an http proxy like [[polipo]]/[[privoxy]]. We will be using tor's daemon directly which listens to port 9050 by default.
-===Pidgin===
+=== Pidgin ===
-Browse through preferences -> proxy and edit it to look like
+You can set up Pidgin to use Tor globally, or per account. To use Tor globally, go to Tools -> Preferences -> Proxy. To use Tor for specific accounts, go to ''Accounts > Manage Accounts'', select the desired account, click Modify, then go to the Proxy tab. The proxy settings are as follows:
   Proxy type 	SOCKS5
   Host 	        127.0.0.1
-  Port 	        9050
+  Port 	        9150
+Note that [https://trac.torproject.org/projects/tor/ticket/8135 some time in 2013] the Port has changed from 9050 to 9150 if you use the Tor Browser Bundle. Try the other value if you receive a "Connection refused" message.
-From now on [[pidgin]] will be using Tor. In some cases, depending on how different accounts are configured in IM services you have set up, you might want to change their proxy settings. Go to Accounts -> Manage Accounts and modify the account you wish, in Proxy tab to read
+== Irssi ==
- Proxy type 	Use Global Proxy Settings
-==Irssi==
 Freenode does not recommend that you use Privoxy with [[Irssi]]. Instead they recommend using the {{Ic|mapaddress}} approach and running {{Ic|torify irssi}} to start it up. Therefore, add the following to {{ic|/etc/tor/torrc}}:
   mapaddress  10.40.40.40 p4fsi4ockecnea7l.onion
@@ Line 120: / Line 178: @@
 Set your identification to nickserv, which will be read when connecting. Supported mechanisms are PLAIN and DH-BLOWFISH.
-  /sasl set <network> <username> <password> <mechanism>
+  /sasl set ''network'' ''username'' ''password'' ''mechanism''
 Connect to Freenode:
-  /connect -network <network> 10.40.40.40
+  /connect -network ''network'' 10.40.40.40
 For more information check [http://freenode.net/irc_servers.shtml#tor Accessing freenode Via Tor] and the [http://freenode.net/sasl/README.txt SASL README] at freenode.net or the [https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO/IrcSilc IRC/SILC Wiki article] at torproject.org.
@@ Line 129: / Line 187: @@
 If you are receiving errors check the ''[https://bbs.archlinux.org/viewtopic.php?pid=956467 Cannot Connect to Freenode IRC using Irssi & Tor]'' thread on the Arch Linux forums.
-==Pacman==
+== Pacman ==
 Pacman download operations (repository DBs, packages, and public keys) can be done using the Tor network. Though relatively extreme, this measure is useful to prevent an adversary (most likely at one's LAN or the mirror) from knowing a subset of the packages you have installed, at the cost of longer latency, lower throughput, possible suspicion, and possible failure (if Tor is being filtered via the current connection).
@@ Line 139: / Line 198: @@
 ...}}
-==Running a Tor Server==
+== Running a Tor server ==
 The Tor network is reliant on people contributing bandwidth. There are several ways to contribute to the network.
-===Running a Tor bridge===
+=== Running a Tor bridge ===
 This involves making your machine an 'entry node' for people who are having trouble connecting to Tor through traditional methods.
-====Configuration====
+==== Configuration ====
 According to https://www.torproject.org/docs/bridges , make your torrc be just these four lines:
@@ Line 155: / Line 215: @@
      Exitpolicy reject *:*
-====Troubleshooting====
+==== Troubleshooting ====
 If you get "Could not bind to 0.0.0.0:443: Permission denied" errors on startup, you'll need to pick a higher ORPort (e.g. 8080), or perhaps [http://www.portforward.com/ forward the port] in your router.
-===Running a "Middleman" relay===
+=== Running a "Middleman" relay ===
 This means that your machine will contribute bandwidth to the 'internal' part of the network, acting as neither an entry nor exit point, merely forwarding bits to and from other Tor nodes/relays.
-====Configuration====
+==== Configuration ====
-You should at least share 20kb/s:
-  Nickname <tornickname>
+You should at least share 20KiB/s:
+  Nickname ''tornickname''
   ORPort 9001
   BandwidthRate 20 KB            # Throttle traffic to 20KB/s
@@ Line 172: / Line 234: @@
   ExitPolicy reject *:*
-===Running a Tor Exit Node===
+=== Running a Tor exit node ===
 Any requests from a Tor user to the regular internet obviously need to exit the network somewhere, and exit nodes provide this vital service. To the accessed host, the request will appear as having originated from your machine. This means that running an exit node is generally considered more legally onerous than running other forms of Tor relays. Before becoming an exit relay, you may want to read [https://blog.torproject.org/running-exit-node Tips for Running an Exit Node With Minimal Harrasment].
-====Configuration====
+==== Configuration ====
-Using the torrc, you can configure which services you wish allow through your exit node.
+Using the torrc, you can configure which services you wish to allow through your exit node.
 Allow all traffic:
   ExitPolicy accept	*:*
@@ Line 188: / Line 250: @@
   ExitPolicy accept *:119        # Accept nntp as well as default exit policy
-==TorDNS==
+== TorDNS ==
-The Tor 0.2.x series provides a built-in DNS forwarder. To enable it add the following lines to the Tor configuration file:
+The Tor 0.2.x series provides a built-in DNS forwarder. To enable it add the following lines to the Tor configuration file and restart the daemon:
 {{hc|/etc/tor/torrc|
   DNSPort 9053
@@ Line 195: / Line 258: @@
   AutomapHostsSuffixes .exit,.onion
 }}
-And restart Tor to load the updated configuration file:
- # rc.d restart tor
 This will allow Tor to accept DNS requests (listening on port 9053 in this example) like a regular DNS server, and resolve the domain via the Tor network. A downside is that it's only able to resolve DNS queries for A-records; MX and NS queries are never answered. For more information see this [https://techstdout.boum.org/TorDns/ Debian-based introduction].
@@ Line 206: / Line 267: @@
 }}
-===Using TorDNS for all DNS queries===
+=== Using TorDNS for all DNS queries ===
-Since TorDNS might be little slow to use TorDNS for all queries it is advised using '''dnsmasq''' to cache the results. So install '''dnsmasq''' and modify its configuration file so that it contains:
+It is possible to configure your system, if so desired, to use TorDNS for ''all'' queries your system makes, regardless of whether or not you eventually use Tor to connect to your final destination. To do this, configure your system to use 127.0.0.1 as its DNS server and edit the 'DNSPort' line in {{ic|/etc/tor/torrc}} to show:
+ DNSPort 53
+Alternatively, you can use a local caching DNS server, such as [[dnsmasq]] or [[pdnsd]], which will also compensate for TorDNS being a little slower than traditional DNS servers. The following instructions will show how to set up ''dnsmasq'' for this purpose.
+Change the tor setting to listen for the DNS request in port 9053 and install {{Pkg|dnsmasq}}.
+Modify its configuration file so that it contains:
 {{hc|/etc/dnsmasq.conf|
   no-resolv
@@ Line 214: / Line 281: @@
   listen-address&#61;127.0.0.1
 }}
-This configuration file sets '''dnsmasq''' so that listen only the local computer and uses only the TorDNS service. It is now needed to edit ''resolv.conf'' so that it uses only the dnsmasq server.
+These configurations set dnsmasq to listen only for requests from the local computer, and to use TorDNS at its sole upstream provider. It is now neccessary to edit {{ic|/etc/resolv.conf}} so that your system will query only the dnsmasq server.
 {{hc|/etc/resolv.conf|
   nameserver 127.0.0.1
 }}
-Start the dns server with
+Start the '''dnsmasq''' daemon.
- # rc.d start dnsmasq
 Finally if you use ''dhcpd'' you would need to change its settings to that it does not alter the resolv configuration file. Just add this line in the configuration file:
@@ Line 227: / Line 293: @@
 If you already have an ''nohook'' line, just add '''resolv.conf''' separated with a comma.
-==Torify==
+== Torify ==
 '''torify''' will allow you use an application via the Tor network without the need to make configuration changes to the application involved. From the man page:
@@ Line 233: / Line 300: @@
 Usage example:
-{{bc|<nowiki>
-$ torify elinks checkip.dyndns.org
-$ torify wget -qO- https://check.torproject.org/ | grep -i congratulations
-</nowiki>}}
-Torify ''will not'', however, perform DNS lookups through the Tor network. A workaround is to use it in conjunction with {{Ic|<nowiki>tor-resolve</nowiki>}} (described above). In this case, the procedure for the first of the above examples would look like this:
+ $ torify elinks checkip.dyndns.org
-{{bc|
+ $ torify wget -qO- https://check.torproject.org/ | grep -i congratulations
-$ tor-resolve checkip.dyndns.org
+Torify ''will not'', however, perform DNS lookups through the Tor network. A workaround is to use it in conjunction with {{ic|<nowiki>tor-resolve</nowiki>}} (described above). In this case, the procedure for the first of the above examples would look like this:
+{{hc|$ tor-resolve checkip.dyndns.org|
 .78.69.70
-$ torify elinks 208.78.69.70
 }}
-==Troubleshooting==
+ $ torify elinks 208.78.69.70
-===Problem with User value===
+== Troubleshooting ==
+=== Problem with user value ===
 If the '''tor''' daemon failed to start, then run the following command as root (or use sudo)
@@ Line 258: / Line 327: @@
   May 23 00:27:24.624 [err] Reading config failed--see warnings above.
-Then it means that the problem is with the User value. So proceed with the following steps.
+Then it means that the problem is with the User value, which likely means that one or more files or directories in your {{ic|/var/lib/tor}} directory is not owned by tor. This can be determined by using the following find command:
-Check the permissions of the directory {{ic|/var/lib/tor}} by running
+ find /var/lib/tor/ ! -user tor
- # ls -l /var/lib/
+Any files or directories listed in the output from this command needs to have its ownership changed. This can be done individually for each file like so:
-If the permission for {{ic|/var/lib/tor}} is as shown below
+ chown tor:tor /var/lib/tor/filename
- drwx------ 2 tor    tor    4096 May 12 21:03 tor
+Or to change everything listed by the above find example, modify the command to this:
-This means that the directory is owned by the user ''tor'' and the group ''tor''.
+ find /var/lib/tor/ ! -user tor -exec chown tor:tor {} \;
-Change the owner to the user ''root'', and the group ''root'' with the command:
- # chown -R root:root /var/lib/tor
+Tor should now start up correctly.
-If you check the permissions again, it should now show
+Still if you cannot start the tor service, run the service using root (this will switch back to the tor user). To do this, change the user name in the {{ic|/etc/tor/torrc}} file:
-  drwx------ 2 root   root   4096 May 12 21:03 tor
+  User tor
-Now open {{ic|/etc/tor/torrc}} and find the following lines
+Now modify the systemd's tor service file {{ic|/usr/lib/systemd/system/tor.service}} as follows
-  ## Uncomment this to start the process in the background... or use
+  [Service]
-  ## --runasdaemon 1 on the command line.
+  User=root
-  RunAsDaemon 1
+  Group=root
- User tor
+  Type=simple
-  Group tor
-Comment out the lines ''User tor'' and ''Group tor'', so that the lines read as
+The process will be run as tor user. For this purpose change user and group ID to tor and also make it writable:
-  ## Uncomment this to start the process in the background... or use
+  # chown -R tor:tor /var/lib/tor/
- ## --runasdaemon 1 on the command line.
+  # chmod -R 755 /var/lib/tor
- RunAsDaemon 1
- #User tor
-  #Group tor
-Save the changes and restart the '''tor''' daemon, it should now work.
+Now save changes and run the daemon:
-  # rc.d restart tor
+  # systemctl --system daemon-reload
+ # systemctl start tor.service
-===Daemon fails on restart===
+=== Daemon fails on restart ===
+{{Out of date|rc.d?}}
-If after issuing {{Ic|/etc/rc.d/tor restart}} you have log entries similar to
+If after issuing a daemon restart you have log entries similar to
   Interrupt: we have stopped accepting new connections, and will shut down in 30 seconds. Interrupt again to exit now
@@ Line 314: / Line 379: @@
 This will allow Tor to shutdown cleanly, and restart after a safe period of time. Remember that this file may be overwritten by upgrades.
-==See Also==
+== See also ==
 * [https://www.torproject.org/docs/tor-doc-unix.html.en Running the Tor client on Linux/BSD/Unix]
 * [https://trac.torproject.org/projects/tor/wiki#Unixish Unix-based Tor Articles]
 * [https://trac.torproject.org/projects/tor/wiki/doc/SupportPrograms Software commonly integrated with Tor]
 * [https://www.torproject.org/docs/tor-hidden-service.html.en How to set up a Tor ''Hidden Service'']

Difference between revisions of "Tor"

Revision as of 04:27, 9 September 2013

Contents

Introduction

Installation

Configuration

Running Tor in a Chroot

Usage

Web browsing

Firefox

Chromium

Luakit

HTTP proxy

Firefox

Polipo

Privoxy

Instant messaging

Pidgin

Irssi

Pacman

Running a Tor server

Running a Tor bridge

Configuration

Troubleshooting

Running a "Middleman" relay

Configuration

Running a Tor exit node

Configuration

TorDNS

Using TorDNS for all DNS queries

Torify

Troubleshooting

Problem with user value

Daemon fails on restart

See also

Navigation menu

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