torsocks.conf
- configuration file for torsocks(8)
SUMMARY
By default, torsocks will assume that it should connect to the SOCKS proxy
running at 127.0.0.1 on port 9050. This is the default address and port for
Tor's socks server on most installations. If you are running a normal Tor
installation and have no special requirements, then you should not need to
create, edit or invoke a configuration file when using torsocks.
Your installation of torsocks includes a default configuration file
that contains values sensible for use with most Tor installations. The
installation location for your default configuration file is:
/etc/torsocks.conf
In order to use a configuration file, you must set the environment variable
TORSOCKS_CONF_FILE with the location of the file.
If TORSOCKS_CONF_FILE is not set, torsocks will attempt to read the configuration
file at /etc/torsocks.conf. If that file cannot be read, torsocks will
use sensible defaults for most Tor installations, i.e. it will assume that
you want to use a SOCKS proxy running at 127.0.0.1 (localhost) on port 9050.
An example of typical usage is provided under the 'example' heading at the
end of this manual page. The script 'usewithtor' provided with your torsocks
installation will set this environment variable for you, and load the
configuration file provided with your installation.
If you want to use a custom file in a different location, you should set the
environment variable yourself and then use the torsocks command, rather than
usewithtor.
OVERVIEW
The configuration for torsocks can be anything from two lines to hundreds of
lines based on the needs at any particular site. The basic idea is to define
any networks the machine can access directly (i.e without the use of a
SOCKS server) and define one or many SOCKS servers to be used to access
other networks (including a 'default' server).
Local networks are declared using the 'local' keyword in the configuration
file. When applications attempt to connect to machines in networks marked
as local torsocks will not attempt to use a SOCKS server to negotiate the
connection.
Obviously if a connection is not to a locally accessible network it will need
to be proxied over a SOCKS server. However, many installations have several
different SOCKS servers to be used to access different internal (and external)
networks. For this reason the configuration file allows the definition of
`paths' as well as a default SOCKS server.
Paths are declared as blocks in the configuration file. That is, they begin
with a 'path {' line in the configuration file and end with a '}' line. Inside
this block directives should be used to declare a SOCKS server (as documented
later in this manual page) and 'reaches' directives should be used to declare
networks and even destination ports in those networks that this server should
be used to reach. N.B Each path MUST define a SOCKS server and contain one or
more 'reaches' directives.
SOCKS server declaration directives that are not contained within a 'path'
block define the default SOCKS server. If torsocks needs to connect to a machine
via a SOCKS server (i.e it isn't a network declared as 'local') and no 'path'
has declared it can reach that network via a 'reaches' directive this server
is used to negotiate the connection.
CONFIGURATION SYNTAX
The basic structure of all lines in the configuration file is:
<directive> = <parameters>
The exception to this is 'path' blocks which look like:
path {
<directive> = <parameters>
}
Empty lines are ignored and all input on a line after a '#' character is
ignored.
DIRECTIVES
The following directives are used in the torsocks configuration file:
server
The IP address of the SOCKS server (e.g "server = 10.1.4.253"). Only one
server may be specified per path block, or one outside a path
block (to define the default server). Unless --disable-hostnames was
specified to configure at compile time the server can be specified as
a hostname (e.g "server = socks.nec.com")
server_port
The port on which the SOCKS server receives requests. Only one server_port
may be specified per path block, or one outside a path (for the default
server). This directive is not required if the server is on the
standard port (1080).
server_type
SOCKS version used by the server. Versions 4 and 5 are supported (but both
for only the connect operation). The default is 4. Only one server_type
may be specified per path block, or one outside a path (for the default
server).
You can use the inspectorsocks utility to determine the type of server, see
the 'UTILITIES' section later in this manual page.
default_user
This specifies the default username to be used for username and password
authentication in SOCKS version 5. In order to determine the username to
use (if the socks server requires username and password authentication)
torsocks first looks for the environment variable TSOCKS_USERNAME, then
looks for this configuration option, then tries to get the local username.
This option is not valid for SOCKS version 4 servers. Only one default_user
may be specified per path block, or one outside a path (for the default
server)
default_pass
This specified the default password to be used for username and password
authentication in SOCKS version 5. In order to determine the password to
use (if the socks server requires username and password authentication)
torsocks first looks for the environment variable TSOCKS_PASSWORD, then
looks for this configuration option. This option is not valid for SOCKS
version 4 servers. Onle one default_pass may be specified per path block,
or one outside a path (for the default server)
local
An IP/Subnet pair specifying a network which may be accessed directly without
proxying through a SOCKS server (e.g "local = 10.0.0.0/255.0.0.0").
Obviously all SOCKS server IP addresses must be in networks specified as
local, otherwise torsocks would need a SOCKS server to reach SOCKS servers.
reaches
This directive is only valid inside a path block. Its parameter is formed
as IP[:startport[-endport]]/Subnet and it specifies a network (and a range
of ports on that network) that can be accessed by the SOCKS server specified
in this path block. For example, in a path block "reaches =
150.0.0.0:80-1024/255.0.0.0" indicates to torsocks that the SOCKS server
specified in the current path block should be used to access any IPs in the
range 150.0.0.0 to 150.255.255.255 when the connection request is for ports
80-1024.
tordns_enable
This enables the use of the 'tordns' feature in torsocks, which overrides the
standard C library name resolution calls to use SOCKS. The default value is
`true'.
tordns_deadpool_range
Tor hidden sites do not have real IP addresses. This specifies what range of
IP addresses will be handed to the application as "cookies" for .onion names.
Of course, you should pick a block of addresses which you aren't going to ever
need to actually connect to. The default value is '127.0.69.0/255.255.255.0'.
tordns_cache_size
This specifies the number of IP addresses looked up through SOCKS to cache.
The default value is 256. Each entry consumes 260 bytes of memory, so the
default adds 66,560 bytes of overhead to each 'torified' process. NOTE: if
the number of IP addresses in tordns_deadpool_range is less than the value
specified for tordns_cache_size, then the cache will be shrunk to fit the
deadpool range. This is to prevent duplicate deadpool addresses from ever
appearing in the cache.
UTILITIES
torsocks comes with two utilities that can be useful in creating and verifying
the torsocks configuration file.
Copyright 2009 Robert Hogan
Copyright 2000 Shaun Clowes
Renamed for use by torsocks to avoid conflict with torsocks by Robert Hogan.
torsocks and its documentation may be freely copied under the terms and
conditions of version 2 of the GNU General Public License, as published
by the Free Software Foundation (Cambridge, Massachusetts, United
States of America).
This documentation is based on the documentation for logwrites, another
shared library interceptor. One line of code from it was used in
torsocks and a lot of the documentation :) logwrites is by
adam@yggdrasil.com (Adam J. Richter) and can be had from ftp.yggdrasil.com
pub/dist/pkg