tor(1)
NAME
tor - The second-generation onion router
SYNOPSIS
tor [OPTION value]...
DESCRIPTION
Tor is a connection-oriented anonymizing communication service. Users
choose a source-routed path through a set of nodes, and negotiate a
"virtual circuit" through the network, in which each node knows its
predecessor and successor, but no others. Traffic flowing down the
circuit is unwrapped by a symmetric key at each node, which reveals the
downstream node.
Basically, Tor provides a distributed network of servers or relays
("onion routers"). Users bounce their TCP streams --- web traffic, ftp,
ssh, etc. --- around the network, and recipients, observers, and even the
relays themselves have difficulty tracking the source of the stream.
By default, tor will act as a client only. To help the network by
providing bandwidth as a relay, change the ORPort configuration option
--- see below. Please also consult the documentation on the Tor Project's
website.
COMMAND-LINE OPTIONS
-h, -help
Display a short help message and exit.
-f FILE
Specify a new configuration file to contain further Tor
configuration options OR pass - to make Tor read its configuration
from standard input. (Default: /etc/tor/torrc, or $HOME/.torrc if
that file is not found)
--allow-missing-torrc
Do not require that configuration file specified by -f exist if
default torrc can be accessed.
--defaults-torrc FILE
Specify a file in which to find default values for Tor options. The
contents of this file are overridden by those in the regular
configuration file, and by those on the command line. (Default:
/etc/tor/torrc-defaults.)
--ignore-missing-torrc
Specifies that Tor should treat a missing torrc file as though it
were empty. Ordinarily, Tor does this for missing default torrc
files, but not for those specified on the command line.
--hash-password PASSWORD
Generates a hashed password for control port access.
--list-fingerprint
Generate your keys and output your nickname and fingerprint.
--verify-config
Verify the configuration file is valid.
--service install [--options command-line options]
Install an instance of Tor as a Windows service, with the provided
command-line options. Current instructions can be found at
https://www.torproject.org/docs/faq#NTService
--service remove|start|stop
Remove, start, or stop a configured Tor Windows service.
--nt-service
Used internally to implement a Windows service.
--list-torrc-options
List all valid options.
--list-deprecated-options
List all valid options that are scheduled to become obsolete in a
future version. (This is a warning, not a promise.)
--version
Display Tor version and exit.
--quiet|--hush
Override the default console log. By default, Tor starts out
logging messages at level "notice" and higher to the console. It
stops doing so after it parses its configuration, if the
configuration tells it to log anywhere else. You can override this
behavior with the --hush option, which tells Tor to only send
warnings and errors to the console, or with the --quiet option,
which tells Tor not to log to the console at all.
--keygen [--newpass]
Running "tor --keygen" creates a new ed25519 master identity key
for a relay, or only a fresh temporary signing key and certificate,
if you already have a master key. Optionally you can encrypt the
master identity key with a passphrase: Tor will ask you for one. If
you don't want to encrypt the master key, just don't enter any
passphrase when asked.
The --newpass option should be used with --keygen only when you
need to add, change, or remove a passphrase on an existing ed25519
master identity key. You will be prompted for the old passphase (if
any), and the new passphrase (if any).
When generating a master key, you will probably want to use
--DataDirectory to control where the keys and certificates will be
stored, and --SigningKeyLifetime to control their lifetimes. Their
behavior is as documented in the server options section below. (You
must have write access to the specified DataDirectory.)
To use the generated files, you must copy them to the
DataDirectory/keys directory of your Tor daemon, and make sure that
they are owned by the user actually running the Tor daemon on your
system.
--passphrase-fd FILEDES
Filedescriptor to read the passphrase from. Note that unlike with
the tor-gencert program, the entire file contents are read and used
as the passphrase, including any trailing newlines. Default: read
from the terminal.
Other options can be specified on the command-line in the format
"--option value", in the format "option value", or in a configuration
file. For instance, you can tell Tor to start listening for SOCKS
connections on port 9999 by passing --SocksPort 9999 or SocksPort 9999
to it on the command line, or by putting "SocksPort 9999" in the
configuration file. You will need to quote options with spaces in them:
if you want Tor to log all debugging messages to debug.log, you will
probably need to say --Log debug file debug.log.
Options on the command line override those in configuration files. See
the next section for more information.
THE CONFIGURATION FILE FORMAT
All configuration options in a configuration are written on a single line by default. They take the form of an option name and a value, or an option name and a quoted value (option value or option "value"). Anything after a # character is treated as a comment. Options are case-insensitive. C-style escaped characters are allowed inside quoted values. To split one configuration entry into multiple lines, use a single backslash character (\) before the end of the line. Comments can be used in such multiline entries, but they must start at the beginning of a line. By default, an option on the command line overrides an option found in the configuration file, and an option in a configuration file overrides one in the defaults file. This rule is simple for options that take a single value, but it can become complicated for options that are allowed to occur more than once: if you specify four SocksPorts in your configuration file, and one more SocksPort on the command line, the option on the command line will replace all of the SocksPorts in the configuration file. If this isn't what you want, prefix the option name with a plus sign (+), and it will be appended to the previous set of options instead. For example, setting SocksPort 9100 will use only port 9100, but setting +SocksPort 9100 will use ports 9100 and 9050 (because this is the default). Alternatively, you might want to remove every instance of an option in the configuration file, and not replace it at all: you might want to say on the command line that you want no SocksPorts at all. To do that, prefix the option name with a forward slash (/). You can use the plus sign (+) and the forward slash (/) in the configuration file and on the command line.
GENERAL OPTIONS
BandwidthRate N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
A token bucket limits the average incoming bandwidth usage on this
node to the specified number of bytes per second, and the average
outgoing bandwidth usage to that same value. If you want to run a
relay in the public network, this needs to be at the very least 75
KBytes for a relay (that is, 600 kbits) or 50 KBytes for a bridge
(400 kbits) --- but of course, more is better; we recommend at least
250 KBytes (2 mbits) if possible. (Default: 1 GByte)
With this option, and in other options that take arguments in
bytes, KBytes, and so on, other formats are also supported.
Notably, "KBytes" can also be written as "kilobytes" or "kb";
"MBytes" can be written as "megabytes" or "MB"; "kbits" can be
written as "kilobits"; and so forth. Tor also accepts "byte" and
"bit" in the singular. The prefixes "tera" and "T" are also
recognized. If no units are given, we default to bytes. To avoid
confusion, we recommend writing "bytes" or "bits" explicitly, since
it's easy to forget that "B" means bytes, not bits.
BandwidthBurst N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
Limit the maximum token bucket size (also known as the burst) to
the given number of bytes in each direction. (Default: 1 GByte)
MaxAdvertisedBandwidth N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
If set, we will not advertise more than this amount of bandwidth
for our BandwidthRate. Server operators who want to reduce the
number of clients who ask to build circuits through them (since
this is proportional to advertised bandwidth rate) can thus reduce
the CPU demands on their server without impacting network
performance.
RelayBandwidthRate N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
If not 0, a separate token bucket limits the average incoming
bandwidth usage for _relayed traffic_ on this node to the specified
number of bytes per second, and the average outgoing bandwidth
usage to that same value. Relayed traffic currently is calculated
to include answers to directory requests, but that may change in
future versions. (Default: 0)
RelayBandwidthBurst N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
If not 0, limit the maximum token bucket size (also known as the
burst) for _relayed traffic_ to the given number of bytes in each
direction. (Default: 0)
PerConnBWRate N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
If set, do separate rate limiting for each connection from a
non-relay. You should never need to change this value, since a
network-wide value is published in the consensus and your relay
will use that value. (Default: 0)
PerConnBWBurst N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
If set, do separate rate limiting for each connection from a
non-relay. You should never need to change this value, since a
network-wide value is published in the consensus and your relay
will use that value. (Default: 0)
ClientTransportPlugin transport socks4|socks5 IP:PORT,
ClientTransportPlugin transport exec path-to-binary [options]
In its first form, when set along with a corresponding Bridge line,
the Tor client forwards its traffic to a SOCKS-speaking proxy on
"IP:PORT". It's the duty of that proxy to properly forward the
traffic to the bridge.
In its second form, when set along with a corresponding Bridge
line, the Tor client launches the pluggable transport proxy
executable in path-to-binary using options as its command-line
options, and forwards its traffic to it. It's the duty of that
proxy to properly forward the traffic to the bridge.
ServerTransportPlugin transport exec path-to-binary [options]
The Tor relay launches the pluggable transport proxy in
path-to-binary using options as its command-line options, and
expects to receive proxied client traffic from it.
ServerTransportListenAddr transport IP:PORT
When this option is set, Tor will suggest IP:PORT as the listening
address of any pluggable transport proxy that tries to launch
transport.
ServerTransportOptions transport k=v k=v ...
When this option is set, Tor will pass the k=v parameters to any
pluggable transport proxy that tries to launch transport.
(Example: ServerTransportOptions obfs45 shared-secret=bridgepasswd
cache=/var/lib/tor/cache)
ExtORPort [address:]port|auto
Open this port to listen for Extended ORPort connections from your
pluggable transports.
ExtORPortCookieAuthFile Path
If set, this option overrides the default location and file name
for the Extended ORPort's cookie file --- the cookie file is needed
for pluggable transports to communicate through the Extended
ORPort.
ExtORPortCookieAuthFileGroupReadable 0|1
If this option is set to 0, don't allow the filesystem group to
read the Extended OR Port cookie file. If the option is set to 1,
make the cookie file readable by the default GID. [Making the file
readable by other groups is not yet implemented; let us know if you
need this for some reason.] (Default: 0)
ConnLimit NUM
The minimum number of file descriptors that must be available to
the Tor process before it will start. Tor will ask the OS for as
many file descriptors as the OS will allow (you can find this by
"ulimit -H -n"). If this number is less than ConnLimit, then Tor
will refuse to start.
You probably don't need to adjust this. It has no effect on Windows
since that platform lacks getrlimit(). (Default: 1000)
DisableNetwork 0|1
When this option is set, we don't listen for or accept any
connections other than controller connections, and we close (and
don't reattempt) any outbound connections. Controllers sometimes
use this option to avoid using the network until Tor is fully
configured. (Default: 0)
ConstrainedSockets 0|1
If set, Tor will tell the kernel to attempt to shrink the buffers
for all sockets to the size specified in ConstrainedSockSize. This
is useful for virtual servers and other environments where system
level TCP buffers may be limited. If you're on a virtual server,
and you encounter the "Error creating network socket: No buffer
space available" message, you are likely experiencing this problem.
The preferred solution is to have the admin increase the buffer
pool for the host itself via /proc/sys/net/ipv4/tcp_mem or
equivalent facility; this configuration option is a second-resort.
The DirPort option should also not be used if TCP buffers are
scarce. The cached directory requests consume additional sockets
which exacerbates the problem.
You should not enable this feature unless you encounter the "no
buffer space available" issue. Reducing the TCP buffers affects
window size for the TCP stream and will reduce throughput in
proportion to round trip time on long paths. (Default: 0)
ConstrainedSockSize N bytes|KBytes
When ConstrainedSockets is enabled the receive and transmit buffers
for all sockets will be set to this limit. Must be a value between
2048 and 262144, in 1024 byte increments. Default of 8192 is
recommended.
ControlPort PORT|unix:path|auto [flags]
If set, Tor will accept connections on this port and allow those
connections to control the Tor process using the Tor Control
Protocol (described in control-spec.txt in torspec). Note: unless
you also specify one or more of HashedControlPassword or
CookieAuthentication, setting this option will cause Tor to allow
any process on the local host to control it. (Setting both
authentication methods means either method is sufficient to
authenticate to Tor.) This option is required for many Tor
controllers; most use the value of 9051. If a unix domain socket is
used, you may quote the path using standard C escape sequences. Set
it to "auto" to have Tor pick a port for you. (Default: 0)
Recognized flags are...
GroupWritable
Unix domain sockets only: makes the socket get created as
group-writable.
WorldWritable
Unix domain sockets only: makes the socket get created as
world-writable.
RelaxDirModeCheck
Unix domain sockets only: Do not insist that the directory that
holds the socket be read-restricted.
ControlListenAddress IP[:PORT]
Bind the controller listener to this address. If you specify a
port, bind to this port rather than the one specified in
ControlPort. We strongly recommend that you leave this alone unless
you know what you're doing, since giving attackers access to your
control listener is really dangerous. This directive can be
specified multiple times to bind to multiple addresses/ports.
(Default: 127.0.0.1)
ControlSocket Path
Like ControlPort, but listens on a Unix domain socket, rather than
a TCP socket. 0 disables ControlSocket (Unix and Unix-like systems
only.)
ControlSocketsGroupWritable 0|1
If this option is set to 0, don't allow the filesystem group to
read and write unix sockets (e.g. ControlSocket). If the option is
set to 1, make the control socket readable and writable by the
default GID. (Default: 0)
HashedControlPassword hashed_password
Allow connections on the control port if they present the password
whose one-way hash is hashed_password. You can compute the hash of
a password by running "tor --hash-password password". You can
provide several acceptable passwords by using more than one
HashedControlPassword line.
CookieAuthentication 0|1
If this option is set to 1, allow connections on the control port
when the connecting process knows the contents of a file named
"control_auth_cookie", which Tor will create in its data directory.
This authentication method should only be used on systems with good
filesystem security. (Default: 0)
CookieAuthFile Path
If set, this option overrides the default location and file name
for Tor's cookie file. (See CookieAuthentication above.)
CookieAuthFileGroupReadable 0|1
If this option is set to 0, don't allow the filesystem group to
read the cookie file. If the option is set to 1, make the cookie
file readable by the default GID. [Making the file readable by
other groups is not yet implemented; let us know if you need this
for some reason.] (Default: 0)
ControlPortWriteToFile Path
If set, Tor writes the address and port of any control port it
opens to this address. Usable by controllers to learn the actual
control port when ControlPort is set to "auto".
ControlPortFileGroupReadable 0|1
If this option is set to 0, don't allow the filesystem group to
read the control port file. If the option is set to 1, make the
control port file readable by the default GID. (Default: 0)
DataDirectory DIR
Store working data in DIR (Default: /var/lib/tor)
DataDirectoryGroupReadable 0|1
If this option is set to 0, don't allow the filesystem group to
read the DataDirectory. If the option is set to 1, make the
DataDirectory readable by the default GID. (Default: 0)
FallbackDir address:port orport=port id=fingerprint [weight=num]
[ipv6=address:orport]
When we're unable to connect to any directory cache for directory
info (usually because we don't know about any yet) we try a
directory authority. Clients also simultaneously try a FallbackDir,
to avoid hangs on client startup if a directory authority is down.
Clients retry FallbackDirs more often than directory authorities,
to reduce the load on the directory authorities. By default, the
directory authorities are also FallbackDirs. Specifying a
FallbackDir replaces Tor's default hard-coded FallbackDirs (if
any). (See the DirAuthority entry for an explanation of each flag.)
UseDefaultFallbackDirs 0|1
Use Tor's default hard-coded FallbackDirs (if any). (When a
FallbackDir line is present, it replaces the hard-coded
FallbackDirs, regardless of the value of UseDefaultFallbackDirs.)
(Default: 1)
DirAuthority [nickname] [flags] address:port fingerprint
Use a nonstandard authoritative directory server at the provided
address and port, with the specified key fingerprint. This option
can be repeated many times, for multiple authoritative directory
servers. Flags are separated by spaces, and determine what kind of
an authority this directory is. By default, an authority is not
authoritative for any directory style or version unless an
appropriate flag is given. Tor will use this authority as a bridge
authoritative directory if the "bridge" flag is set. If a flag
"orport=port" is given, Tor will use the given port when opening
encrypted tunnels to the dirserver. If a flag "weight=num" is
given, then the directory server is chosen randomly with
probability proportional to that weight (default 1.0). If a flag
"v3ident=fp" is given, the dirserver is a v3 directory authority
whose v3 long-term signing key has the fingerprint fp. Lastly, if
an "ipv6=address:orport" flag is present, then the directory
authority is listening for IPv6 connections on the indicated IPv6
address and OR Port.
Tor will contact the authority at address:port (the DirPort) to
download directory documents. If an IPv6 address is supplied, Tor
will also download directory documents at the IPv6 address on the
DirPort.
If no DirAuthority line is given, Tor will use the default
directory authorities. NOTE: this option is intended for setting up
a private Tor network with its own directory authorities. If you
use it, you will be distinguishable from other users, because you
won't believe the same authorities they do.
DirAuthorityFallbackRate NUM
When configured to use both directory authorities and fallback
directories, the directory authorities also work as fallbacks. They
are chosen with their regular weights, multiplied by this number,
which should be 1.0 or less. (Default: 1.0)
AlternateDirAuthority [nickname] [flags] address:port fingerprint
AlternateBridgeAuthority [nickname] [flags] address:port fingerprint
These options behave as DirAuthority, but they replace fewer of the
default directory authorities. Using AlternateDirAuthority replaces
the default Tor directory authorities, but leaves the default
bridge authorities in place. Similarly, AlternateBridgeAuthority
replaces the default bridge authority, but leaves the directory
authorities alone.
DisableAllSwap 0|1
If set to 1, Tor will attempt to lock all current and future memory
pages, so that memory cannot be paged out. Windows, OS X and
Solaris are currently not supported. We believe that this feature
works on modern Gnu/Linux distributions, and that it should work on
*BSD systems (untested). This option requires that you start your
Tor as root, and you should use the User option to properly reduce
Tor's privileges. (Default: 0)
DisableDebuggerAttachment 0|1
If set to 1, Tor will attempt to prevent basic debugging attachment
attempts by other processes. This may also keep Tor from generating
core files if it crashes. It has no impact for users who wish to
attach if they have CAP_SYS_PTRACE or if they are root. We believe
that this feature works on modern Gnu/Linux distributions, and that
it may also work on *BSD systems (untested). Some modern Gnu/Linux
systems such as Ubuntu have the kernel.yama.ptrace_scope sysctl and
by default enable it as an attempt to limit the PTRACE scope for
all user processes by default. This feature will attempt to limit
the PTRACE scope for Tor specifically - it will not attempt to
alter the system wide ptrace scope as it may not even exist. If you
wish to attach to Tor with a debugger such as gdb or strace you
will want to set this to 0 for the duration of your debugging.
Normal users should leave it on. Disabling this option while Tor is
running is prohibited. (Default: 1)
FetchDirInfoEarly 0|1
If set to 1, Tor will always fetch directory information like other
directory caches, even if you don't meet the normal criteria for
fetching early. Normal users should leave it off. (Default: 0)
FetchDirInfoExtraEarly 0|1
If set to 1, Tor will fetch directory information before other
directory caches. It will attempt to download directory information
closer to the start of the consensus period. Normal users should
leave it off. (Default: 0)
FetchHidServDescriptors 0|1
If set to 0, Tor will never fetch any hidden service descriptors
from the rendezvous directories. This option is only useful if
you're using a Tor controller that handles hidden service fetches
for you. (Default: 1)
FetchServerDescriptors 0|1
If set to 0, Tor will never fetch any network status summaries or
server descriptors from the directory servers. This option is only
useful if you're using a Tor controller that handles directory
fetches for you. (Default: 1)
FetchUselessDescriptors 0|1
If set to 1, Tor will fetch every non-obsolete descriptor from the
authorities that it hears about. Otherwise, it will avoid fetching
useless descriptors, for example for routers that are not running.
This option is useful if you're using the contributed "exitlist"
script to enumerate Tor nodes that exit to certain addresses.
(Default: 0)
HTTPProxy host[:port]
Tor will make all its directory requests through this host:port (or
host:80 if port is not specified), rather than connecting directly
to any directory servers.
HTTPProxyAuthenticator username:password
If defined, Tor will use this username:password for Basic HTTP
proxy authentication, as in RFC 2617. This is currently the only
form of HTTP proxy authentication that Tor supports; feel free to
submit a patch if you want it to support others.
HTTPSProxy host[:port]
Tor will make all its OR (SSL) connections through this host:port
(or host:443 if port is not specified), via HTTP CONNECT rather
than connecting directly to servers. You may want to set
FascistFirewall to restrict the set of ports you might try to
connect to, if your HTTPS proxy only allows connecting to certain
ports.
HTTPSProxyAuthenticator username:password
If defined, Tor will use this username:password for Basic HTTPS
proxy authentication, as in RFC 2617. This is currently the only
form of HTTPS proxy authentication that Tor supports; feel free to
submit a patch if you want it to support others.
Sandbox 0|1
If set to 1, Tor will run securely through the use of a syscall
sandbox. Otherwise the sandbox will be disabled. The option is
currently an experimental feature. (Default: 0)
Socks4Proxy host[:port]
Tor will make all OR connections through the SOCKS 4 proxy at
host:port (or host:1080 if port is not specified).
Socks5Proxy host[:port]
Tor will make all OR connections through the SOCKS 5 proxy at
host:port (or host:1080 if port is not specified).
Socks5ProxyUsername username
Socks5ProxyPassword password
If defined, authenticate to the SOCKS 5 server using username and
password in accordance to RFC 1929. Both username and password must
be between 1 and 255 characters.
SocksSocketsGroupWritable 0|1
If this option is set to 0, don't allow the filesystem group to
read and write unix sockets (e.g. SocksSocket). If the option is
set to 1, make the SocksSocket socket readable and writable by the
default GID. (Default: 0)
KeepalivePeriod NUM
To keep firewalls from expiring connections, send a padding
keepalive cell every NUM seconds on open connections that are in
use. If the connection has no open circuits, it will instead be
closed after NUM seconds of idleness. (Default: 5 minutes)
Log minSeverity[-maxSeverity] stderr|stdout|syslog
Send all messages between minSeverity and maxSeverity to the
standard output stream, the standard error stream, or to the system
log. (The "syslog" value is only supported on Unix.) Recognized
severity levels are debug, info, notice, warn, and err. We advise
using "notice" in most cases, since anything more verbose may
provide sensitive information to an attacker who obtains the logs.
If only one severity level is given, all messages of that level or
higher will be sent to the listed destination.
Log minSeverity[-maxSeverity] file FILENAME
As above, but send log messages to the listed filename. The "Log"
option may appear more than once in a configuration file. Messages
are sent to all the logs that match their severity level.
Log [domain,...]minSeverity[-maxSeverity] ... file FILENAME
Log [domain,...]minSeverity[-maxSeverity] ... stderr|stdout|syslog
As above, but select messages by range of log severity and by a set
of "logging domains". Each logging domain corresponds to an area of
functionality inside Tor. You can specify any number of severity
ranges for a single log statement, each of them prefixed by a
comma-separated list of logging domains. You can prefix a domain
with ~ to indicate negation, and use * to indicate "all domains".
If you specify a severity range without a list of domains, it
matches all domains.
This is an advanced feature which is most useful for debugging one
or two of Tor's subsystems at a time.
The currently recognized domains are: general, crypto, net, config,
fs, protocol, mm, http, app, control, circ, rend, bug, dir,
dirserv, or, edge, acct, hist, and handshake. Domain names are
case-insensitive.
For example, "Log [handshake]debug [~net,~mm]info notice stdout"
sends to stdout: all handshake messages of any severity, all
info-and-higher messages from domains other than networking and
memory management, and all messages of severity notice or higher.
LogMessageDomains 0|1
If 1, Tor includes message domains with each log message. Every log
message currently has at least one domain; most currently have
exactly one. This doesn't affect controller log messages. (Default:
0)
MaxUnparseableDescSizeToLog N bytes|KBytes|MBytes|GBytes
Unparseable descriptors (e.g. for votes, consensuses, routers) are
logged in separate files by hash, up to the specified size in
total. Note that only files logged during the lifetime of this Tor
process count toward the total; this is intended to be used to
debug problems without opening live servers to resource exhaustion
attacks. (Default: 10 MB)
OutboundBindAddress IP
Make all outbound connections originate from the IP address
specified. This is only useful when you have multiple network
interfaces, and you want all of Tor's outgoing connections to use a
single one. This option may be used twice, once with an IPv4
address and once with an IPv6 address. This setting will be ignored
for connections to the loopback addresses (127.0.0.0/8 and ::1).
PidFile FILE
On startup, write our PID to FILE. On clean shutdown, remove FILE.
ProtocolWarnings 0|1
If 1, Tor will log with severity 'warn' various cases of other
parties not following the Tor specification. Otherwise, they are
logged with severity 'info'. (Default: 0)
PredictedPortsRelevanceTime NUM
Set how long, after the client has made an anonymized connection to
a given port, we will try to make sure that we build circuits to
exits that support that port. The maximum value for this option is
1 hour. (Default: 1 hour)
RunAsDaemon 0|1
If 1, Tor forks and daemonizes to the background. This option has
no effect on Windows; instead you should use the --service
command-line option. (Default: 0)
LogTimeGranularity NUM
Set the resolution of timestamps in Tor's logs to NUM milliseconds.
NUM must be positive and either a divisor or a multiple of 1
second. Note that this option only controls the granularity written
by Tor to a file or console log. Tor does not (for example) "batch
up" log messages to affect times logged by a controller, times
attached to syslog messages, or the mtime fields on log files.
(Default: 1 second)
TruncateLogFile 0|1
If 1, Tor will overwrite logs at startup and in response to a HUP
signal, instead of appending to them. (Default: 0)
SyslogIdentityTag tag
When logging to syslog, adds a tag to the syslog identity such that
log entries are marked with "Tor-tag". (Default: none)
SafeLogging 0|1|relay
Tor can scrub potentially sensitive strings from log messages (e.g.
addresses) by replacing them with the string [scrubbed]. This way
logs can still be useful, but they don't leave behind personally
identifying information about what sites a user might have visited.
If this option is set to 0, Tor will not perform any scrubbing, if
it is set to 1, all potentially sensitive strings are replaced. If
it is set to relay, all log messages generated when acting as a
relay are sanitized, but all messages generated when acting as a
client are not. (Default: 1)
User Username
On startup, setuid to this user and setgid to their primary group.
KeepBindCapabilities 0|1|auto
On Linux, when we are started as root and we switch our identity
using the User option, the KeepBindCapabilities option tells us
whether to try to retain our ability to bind to low ports. If this
value is 1, we try to keep the capability; if it is 0 we do not;
and if it is auto, we keep the capability only if we are configured
to listen on a low port. (Default: auto.)
HardwareAccel 0|1
If non-zero, try to use built-in (static) crypto hardware
acceleration when available. (Default: 0)
AccelName NAME
When using OpenSSL hardware crypto acceleration attempt to load the
dynamic engine of this name. This must be used for any dynamic
hardware engine. Names can be verified with the openssl engine
command.
AccelDir DIR
Specify this option if using dynamic hardware acceleration and the
engine implementation library resides somewhere other than the
OpenSSL default.
AvoidDiskWrites 0|1
If non-zero, try to write to disk less frequently than we would
otherwise. This is useful when running on flash memory or other
media that support only a limited number of writes. (Default: 0)
CircuitPriorityHalflife NUM1
If this value is set, we override the default algorithm for
choosing which circuit's cell to deliver or relay next. When the
value is 0, we round-robin between the active circuits on a
connection, delivering one cell from each in turn. When the value
is positive, we prefer delivering cells from whichever connection
has the lowest weighted cell count, where cells are weighted
exponentially according to the supplied CircuitPriorityHalflife
value (in seconds). If this option is not set at all, we use the
behavior recommended in the current consensus networkstatus. This
is an advanced option; you generally shouldn't have to mess with
it. (Default: not set)
CountPrivateBandwidth 0|1
If this option is set, then Tor's rate-limiting applies not only to
remote connections, but also to connections to private addresses
like 127.0.0.1 or 10.0.0.1. This is mostly useful for debugging
rate-limiting. (Default: 0)
CLIENT OPTIONS
The following options are useful only for clients (that is, if
SocksPort, TransPort, DNSPort, or NATDPort is non-zero):
AllowInvalidNodes entry|exit|middle|introduction|rendezvous|...
If some Tor servers are obviously not working right, the directory
authorities can manually mark them as invalid, meaning that it's
not recommended you use them for entry or exit positions in your
circuits. You can opt to use them in some circuit positions,
though. The default is "middle,rendezvous", and other choices are
not advised.
ExcludeSingleHopRelays 0|1
This option controls whether circuits built by Tor will include
relays with the AllowSingleHopExits flag set to true. If
ExcludeSingleHopRelays is set to 0, these relays will be included.
Note that these relays might be at higher risk of being seized or
observed, so they are not normally included. Also note that
relatively few clients turn off this option, so using these relays
might make your client stand out. (Default: 1)
Bridge [transport] IP:ORPort [fingerprint]
When set along with UseBridges, instructs Tor to use the relay at
"IP:ORPort" as a "bridge" relaying into the Tor network. If
"fingerprint" is provided (using the same format as for
DirAuthority), we will verify that the relay running at that
location has the right fingerprint. We also use fingerprint to look
up the bridge descriptor at the bridge authority, if it's provided
and if UpdateBridgesFromAuthority is set too.
If "transport" is provided, it must match a ClientTransportPlugin
line. We then use that pluggable transport's proxy to transfer data
to the bridge, rather than connecting to the bridge directly. Some
transports use a transport-specific method to work out the remote
address to connect to. These transports typically ignore the
"IP:ORPort" specified in the bridge line.
LearnCircuitBuildTimeout 0|1
If 0, CircuitBuildTimeout adaptive learning is disabled. (Default:
1)
CircuitBuildTimeout NUM
Try for at most NUM seconds when building circuits. If the circuit
isn't open in that time, give up on it. If LearnCircuitBuildTimeout
is 1, this value serves as the initial value to use before a
timeout is learned. If LearnCircuitBuildTimeout is 0, this value is
the only value used. (Default: 60 seconds)
CircuitIdleTimeout NUM
If we have kept a clean (never used) circuit around for NUM
seconds, then close it. This way when the Tor client is entirely
idle, it can expire all of its circuits, and then expire its TLS
connections. Also, if we end up making a circuit that is not useful
for exiting any of the requests we're receiving, it won't forever
take up a slot in the circuit list. (Default: 1 hour)
CircuitStreamTimeout NUM
If non-zero, this option overrides our internal timeout schedule
for how many seconds until we detach a stream from a circuit and
try a new circuit. If your network is particularly slow, you might
want to set this to a number like 60. (Default: 0)
ClientOnly 0|1
If set to 1, Tor will not run as a relay or serve directory
requests, even if the ORPort, ExtORPort, or DirPort options are
set. (This config option is mostly unnecessary: we added it back
when we were considering having Tor clients auto-promote themselves
to being relays if they were stable and fast enough. The current
behavior is simply that Tor is a client unless ORPort, ExtORPort,
or DirPort are configured.) (Default: 0)
ExcludeNodes node,node,...
A list of identity fingerprints, country codes, and address
patterns of nodes to avoid when building a circuit. Country codes
are 2-letter ISO3166 codes, and must be wrapped in braces;
fingerprints may be preceded by a dollar sign. (Example:
ExcludeNodes ABCD1234CDEF5678ABCD1234CDEF5678ABCD1234, {cc},
255.254.0.0/8)
By default, this option is treated as a preference that Tor is
allowed to override in order to keep working. For example, if you
try to connect to a hidden service, but you have excluded all of
the hidden service's introduction points, Tor will connect to one
of them anyway. If you do not want this behavior, set the
StrictNodes option (documented below).
Note also that if you are a relay, this (and the other node
selection options below) only affects your own circuits that Tor
builds for you. Clients can still build circuits through you to any
node. Controllers can tell Tor to build circuits through any node.
Country codes are case-insensitive. The code "{??}" refers to nodes
whose country can't be identified. No country code, including {??},
works if no GeoIPFile can be loaded. See also the
GeoIPExcludeUnknown option below.
ExcludeExitNodes node,node,...
A list of identity fingerprints, country codes, and address
patterns of nodes to never use when picking an exit node---that is,
a node that delivers traffic for you outside the Tor network. Note
that any node listed in ExcludeNodes is automatically considered to
be part of this list too. See the ExcludeNodes option for more
information on how to specify nodes. See also the caveats on the
"ExitNodes" option below.
GeoIPExcludeUnknown 0|1|auto
If this option is set to auto, then whenever any country code is
set in ExcludeNodes or ExcludeExitNodes, all nodes with unknown
country ({??} and possibly {A1}) are treated as excluded as well.
If this option is set to 1, then all unknown countries are treated
as excluded in ExcludeNodes and ExcludeExitNodes. This option has
no effect when a GeoIP file isn't configured or can't be found.
(Default: auto)
ExitNodes node,node,...
A list of identity fingerprints, country codes, and address
patterns of nodes to use as exit node---that is, a node that
delivers traffic for you outside the Tor network. See the
ExcludeNodes option for more information on how to specify nodes.
Note that if you list too few nodes here, or if you exclude too
many exit nodes with ExcludeExitNodes, you can degrade
functionality. For example, if none of the exits you list allows
traffic on port 80 or 443, you won't be able to browse the web.
Note also that not every circuit is used to deliver traffic outside
of the Tor network. It is normal to see non-exit circuits (such as
those used to connect to hidden services, those that do directory
fetches, those used for relay reachability self-tests, and so on)
that end at a non-exit node. To keep a node from being used
entirely, see ExcludeNodes and StrictNodes.
The ExcludeNodes option overrides this option: any node listed in
both ExitNodes and ExcludeNodes is treated as excluded.
The .exit address notation, if enabled via AllowDotExit, overrides
this option.
EntryNodes node,node,...
A list of identity fingerprints and country codes of nodes to use
for the first hop in your normal circuits. Normal circuits include
all circuits except for direct connections to directory servers.
The Bridge option overrides this option; if you have configured
bridges and UseBridges is 1, the Bridges are used as your entry
nodes.
The ExcludeNodes option overrides this option: any node listed in
both EntryNodes and ExcludeNodes is treated as excluded. See the
ExcludeNodes option for more information on how to specify nodes.
StrictNodes 0|1
If StrictNodes is set to 1, Tor will treat the ExcludeNodes option
as a requirement to follow for all the circuits you generate, even
if doing so will break functionality for you. If StrictNodes is set
to 0, Tor will still try to avoid nodes in the ExcludeNodes list,
but it will err on the side of avoiding unexpected errors.
Specifically, StrictNodes 0 tells Tor that it is okay to use an
excluded node when it is necessary to perform relay reachability
self-tests, connect to a hidden service, provide a hidden service
to a client, fulfill a .exit request, upload directory information,
or download directory information. (Default: 0)
FascistFirewall 0|1
If 1, Tor will only create outgoing connections to ORs running on
ports that your firewall allows (defaults to 80 and 443; see
FirewallPorts). This will allow you to run Tor as a client behind a
firewall with restrictive policies, but will not allow you to run
as a server behind such a firewall. If you prefer more fine-grained
control, use ReachableAddresses instead.
FirewallPorts PORTS
A list of ports that your firewall allows you to connect to. Only
used when FascistFirewall is set. This option is deprecated; use
ReachableAddresses instead. (Default: 80, 443)
ReachableAddresses ADDR[/MASK][:PORT]...
A comma-separated list of IP addresses and ports that your firewall
allows you to connect to. The format is as for the addresses in
ExitPolicy, except that "accept" is understood unless "reject" is
explicitly provided. For example, 'ReachableAddresses 99.0.0.0/8,
reject 18.0.0.0/8:80, accept *:80' means that your firewall allows
connections to everything inside net 99, rejects port 80
connections to net 18, and accepts connections to port 80
otherwise. (Default: 'accept *:*'.)
ReachableDirAddresses ADDR[/MASK][:PORT]...
Like ReachableAddresses, a list of addresses and ports. Tor will
obey these restrictions when fetching directory information, using
standard HTTP GET requests. If not set explicitly then the value of
ReachableAddresses is used. If HTTPProxy is set then these
connections will go through that proxy.
ReachableORAddresses ADDR[/MASK][:PORT]...
Like ReachableAddresses, a list of addresses and ports. Tor will
obey these restrictions when connecting to Onion Routers, using
TLS/SSL. If not set explicitly then the value of ReachableAddresses
is used. If HTTPSProxy is set then these connections will go
through that proxy.
The separation between ReachableORAddresses and
ReachableDirAddresses is only interesting when you are connecting
through proxies (see HTTPProxy and HTTPSProxy). Most proxies limit
TLS connections (which Tor uses to connect to Onion Routers) to
port 443, and some limit HTTP GET requests (which Tor uses for
fetching directory information) to port 80.
HidServAuth onion-address auth-cookie [service-name]
Client authorization for a hidden service. Valid onion addresses
contain 16 characters in a-z2-7 plus ".onion", and valid auth
cookies contain 22 characters in A-Za-z0-9+/. The service name is
only used for internal purposes, e.g., for Tor controllers. This
option may be used multiple times for different hidden services. If
a hidden service uses authorization and this option is not set, the
hidden service is not accessible. Hidden services can be configured
to require authorization using the HiddenServiceAuthorizeClient
option.
CloseHSClientCircuitsImmediatelyOnTimeout 0|1
If 1, Tor will close unfinished hidden service client circuits
which have not moved closer to connecting to their destination
hidden service when their internal state has not changed for the
duration of the current circuit-build timeout. Otherwise, such
circuits will be left open, in the hope that they will finish
connecting to their destination hidden services. In either case,
another set of introduction and rendezvous circuits for the same
destination hidden service will be launched. (Default: 0)
CloseHSServiceRendCircuitsImmediatelyOnTimeout 0|1
If 1, Tor will close unfinished hidden-service-side rendezvous
circuits after the current circuit-build timeout. Otherwise, such
circuits will be left open, in the hope that they will finish
connecting to their destinations. In either case, another
rendezvous circuit for the same destination client will be
launched. (Default: 0)
LongLivedPorts PORTS
A list of ports for services that tend to have long-running
connections (e.g. chat and interactive shells). Circuits for
streams that use these ports will contain only high-uptime nodes,
to reduce the chance that a node will go down before the stream is
finished. Note that the list is also honored for circuits (both
client and service side) involving hidden services whose virtual
port is in this list. (Default: 21, 22, 706, 1863, 5050, 5190,
5222, 5223, 6523, 6667, 6697, 8300)
MapAddress address newaddress
When a request for address arrives to Tor, it will transform to
newaddress before processing it. For example, if you always want
connections to www.example.com to exit via torserver (where
torserver is the fingerprint of the server), use "MapAddress
www.example.com www.example.com.torserver.exit". If the value is
prefixed with a "*.", matches an entire domain. For example, if you
always want connections to example.com and any if its subdomains to
exit via torserver (where torserver is the fingerprint of the
server), use "MapAddress *.example.com
*.example.com.torserver.exit". (Note the leading "*." in each part
of the directive.) You can also redirect all subdomains of a domain
to a single address. For example, "MapAddress *.example.com
www.example.com".
NOTES:
1. When evaluating MapAddress expressions Tor stops when it hits
the most recently added expression that matches the requested
address. So if you have the following in your torrc,
www.torproject.org will map to 1.1.1.1:
MapAddress www.torproject.org 2.2.2.2
MapAddress www.torproject.org 1.1.1.1
2. Tor evaluates the MapAddress configuration until it finds no
matches. So if you have the following in your torrc,
www.torproject.org will map to 2.2.2.2:
MapAddress 1.1.1.1 2.2.2.2
MapAddress www.torproject.org 1.1.1.1
3. The following MapAddress expression is invalid (and will be
ignored) because you cannot map from a specific address to a
wildcard address:
MapAddress www.torproject.org *.torproject.org.torserver.exit
4. Using a wildcard to match only part of a string (as in
*ample.com) is also invalid.
NewCircuitPeriod NUM
Every NUM seconds consider whether to build a new circuit.
(Default: 30 seconds)
MaxCircuitDirtiness NUM
Feel free to reuse a circuit that was first used at most NUM
seconds ago, but never attach a new stream to a circuit that is too
old. For hidden services, this applies to the last time a circuit
was used, not the first. Circuits with streams constructed with
SOCKS authentication via SocksPorts that have
KeepAliveIsolateSOCKSAuth ignore this value. (Default: 10 minutes)
MaxClientCircuitsPending NUM
Do not allow more than NUM circuits to be pending at a time for
handling client streams. A circuit is pending if we have begun
constructing it, but it has not yet been completely constructed.
(Default: 32)
NodeFamily node,node,...
The Tor servers, defined by their identity fingerprints, constitute
a "family" of similar or co-administered servers, so never use any
two of them in the same circuit. Defining a NodeFamily is only
needed when a server doesn't list the family itself (with
MyFamily). This option can be used multiple times; each instance
defines a separate family. In addition to nodes, you can also list
IP address and ranges and country codes in {curly braces}. See the
ExcludeNodes option for more information on how to specify nodes.
EnforceDistinctSubnets 0|1
If 1, Tor will not put two servers whose IP addresses are "too
close" on the same circuit. Currently, two addresses are "too
close" if they lie in the same /16 range. (Default: 1)
SocksPort [address:]port|unix:path|auto [flags] [isolation flags]
Open this port to listen for connections from SOCKS-speaking
applications. Set this to 0 if you don't want to allow application
connections via SOCKS. Set it to "auto" to have Tor pick a port for
you. This directive can be specified multiple times to bind to
multiple addresses/ports. If a unix domain socket is used, you may
quote the path using standard C escape sequences. (Default: 9050)
NOTE: Although this option allows you to specify an IP address
other than localhost, you should do so only with extreme caution.
The SOCKS protocol is unencrypted and (as we use it)
unauthenticated, so exposing it in this way could leak your
information to anybody watching your network, and allow anybody to
use your computer as an open proxy.
The isolation flags arguments give Tor rules for which streams
received on this SocksPort are allowed to share circuits with one
another. Recognized isolation flags are:
IsolateClientAddr
Don't share circuits with streams from a different client
address. (On by default and strongly recommended when
supported; you can disable it with NoIsolateClientAddr.
Unsupported and force-disabled when using Unix domain sockets.)
IsolateSOCKSAuth
Don't share circuits with streams for which different SOCKS
authentication was provided. (On by default; you can disable it
with NoIsolateSOCKSAuth.)
IsolateClientProtocol
Don't share circuits with streams using a different protocol.
(SOCKS 4, SOCKS 5, TransPort connections, NATDPort connections,
and DNSPort requests are all considered to be different
protocols.)
IsolateDestPort
Don't share circuits with streams targeting a different
destination port.
IsolateDestAddr
Don't share circuits with streams targeting a different
destination address.
KeepAliveIsolateSOCKSAuth
If IsolateSOCKSAuth is enabled, keep alive circuits that have
streams with SOCKS authentication set indefinitely.
SessionGroup=INT
If no other isolation rules would prevent it, allow streams on
this port to share circuits with streams from every other port
with the same session group. (By default, streams received on
different SocksPorts, TransPorts, etc are always isolated from
one another. This option overrides that behavior.)
Other recognized flags for a SocksPort are:
NoIPv4Traffic
Tell exits to not connect to IPv4 addresses in response to
SOCKS requests on this connection.
IPv6Traffic
Tell exits to allow IPv6 addresses in response to SOCKS
requests on this connection, so long as SOCKS5 is in use.
(SOCKS4 can't handle IPv6.)
PreferIPv6
Tells exits that, if a host has both an IPv4 and an IPv6
address, we would prefer to connect to it via IPv6. (IPv4 is
the default.)
NoDNSRequest
Do not ask exits to resolve DNS addresses in SOCKS5 requests.
Tor will connect to IPv4 addresses, IPv6 addresses (if
IPv6Traffic is set) and .onion addresses.
NoOnionTraffic
Do not connect to .onion addresses in SOCKS5 requests.
OnionTrafficOnly
Tell the tor client to only connect to .onion addresses in
response to SOCKS5 requests on this connection. This is
equivalent to NoDNSRequest, NoIPv4Traffic, NoIPv6Traffic. The
corresponding NoOnionTrafficOnly flag is not supported.
CacheIPv4DNS
Tells the client to remember IPv4 DNS answers we receive from
exit nodes via this connection. (On by default.)
CacheIPv6DNS
Tells the client to remember IPv6 DNS answers we receive from
exit nodes via this connection.
GroupWritable
Unix domain sockets only: makes the socket get created as
group-writable.
WorldWritable
Unix domain sockets only: makes the socket get created as
world-writable.
CacheDNS
Tells the client to remember all DNS answers we receive from
exit nodes via this connection.
UseIPv4Cache
Tells the client to use any cached IPv4 DNS answers we have
when making requests via this connection. (NOTE: This option,
along UseIPv6Cache and UseDNSCache, can harm your anonymity,
and probably won't help performance as much as you might
expect. Use with care!)
UseIPv6Cache
Tells the client to use any cached IPv6 DNS answers we have
when making requests via this connection.
UseDNSCache
Tells the client to use any cached DNS answers we have when
making requests via this connection.
PreferIPv6Automap
When serving a hostname lookup request on this port that should
get automapped (according to AutomapHostsOnResolve), if we
could return either an IPv4 or an IPv6 answer, prefer an IPv6
answer. (On by default.)
PreferSOCKSNoAuth
Ordinarily, when an application offers both "username/password
authentication" and "no authentication" to Tor via SOCKS5, Tor
selects username/password authentication so that
IsolateSOCKSAuth can work. This can confuse some applications,
if they offer a username/password combination then get confused
when asked for one. You can disable this behavior, so that Tor
will select "No authentication" when IsolateSOCKSAuth is
disabled, or when this option is set.
Flags are processed left to right. If flags conflict, the last flag on the
line is used, and all earlier flags are ignored. No error is issued for
conflicting flags.
SocksListenAddress IP[:PORT]
Bind to this address to listen for connections from Socks-speaking
applications. (Default: 127.0.0.1) You can also specify a port
(e.g. 192.168.0.1:9100). This directive can be specified multiple
times to bind to multiple addresses/ports. (DEPRECATED: As of
0.2.3.x-alpha, you can now use multiple SocksPort entries, and
provide addresses for SocksPort entries, so SocksListenAddress no
longer has a purpose. For backward compatibility,
SocksListenAddress is only allowed when SocksPort is just a port
number.)
SocksPolicy policy,policy,...
Set an entrance policy for this server, to limit who can connect to
the SocksPort and DNSPort ports. The policies have the same form as
exit policies below, except that port specifiers are ignored. Any
address not matched by some entry in the policy is accepted.
SocksTimeout NUM
Let a socks connection wait NUM seconds handshaking, and NUM
seconds unattached waiting for an appropriate circuit, before we
fail it. (Default: 2 minutes)
TokenBucketRefillInterval NUM [msec|second]
Set the refill interval of Tor's token bucket to NUM milliseconds.
NUM must be between 1 and 1000, inclusive. Note that the configured
bandwidth limits are still expressed in bytes per second: this
option only affects the frequency with which Tor checks to see
whether previously exhausted connections may read again. (Default:
100 msec)
TrackHostExits host,.domain,...
For each value in the comma separated list, Tor will track recent
connections to hosts that match this value and attempt to reuse the
same exit node for each. If the value is prepended with a '.', it
is treated as matching an entire domain. If one of the values is
just a '.', it means match everything. This option is useful if you
frequently connect to sites that will expire all your
authentication cookies (i.e. log you out) if your IP address
changes. Note that this option does have the disadvantage of making
it more clear that a given history is associated with a single
user. However, most people who would wish to observe this will
observe it through cookies or other protocol-specific means anyhow.
TrackHostExitsExpire NUM
Since exit servers go up and down, it is desirable to expire the
association between host and exit server after NUM seconds. The
default is 1800 seconds (30 minutes).
UpdateBridgesFromAuthority 0|1
When set (along with UseBridges), Tor will try to fetch bridge
descriptors from the configured bridge authorities when feasible.
It will fall back to a direct request if the authority responds
with a 404. (Default: 0)
UseBridges 0|1
When set, Tor will fetch descriptors for each bridge listed in the
"Bridge" config lines, and use these relays as both entry guards
and directory guards. (Default: 0)
UseEntryGuards 0|1
If this option is set to 1, we pick a few long-term entry servers,
and try to stick with them. This is desirable because constantly
changing servers increases the odds that an adversary who owns some
servers will observe a fraction of your paths. Entry Guards can not
be used by Directory Authorities, Single Onion Services, and
Tor2web clients. In these cases, the this option is ignored.
(Default: 1)
UseEntryGuardsAsDirGuards 0|1
If this option is set to 1, and UseEntryGuards is also set to 1, we
try to use our entry guards as directory guards, and failing that,
pick more nodes to act as our directory guards. This helps prevent
an adversary from enumerating clients. It's only available for
clients (non-relay, non-bridge) that aren't configured to download
any non-default directory material. It doesn't currently do
anything when we lack a live consensus. (Default: 1)
GuardfractionFile FILENAME
V3 authoritative directories only. Configures the location of the
guardfraction file which contains information about how long relays
have been guards. (Default: unset)
UseGuardFraction 0|1|auto
This torrc option specifies whether clients should use the
guardfraction information found in the consensus during path
selection. If it's set to auto, clients will do what the
UseGuardFraction consensus parameter tells them to do. (Default:
auto)
NumEntryGuards NUM
If UseEntryGuards is set to 1, we will try to pick a total of NUM
routers as long-term entries for our circuits. If NUM is 0, we try
to learn the number from the NumEntryGuards consensus parameter,
and default to 3 if the consensus parameter isn't set. (Default: 0)
NumDirectoryGuards NUM
If UseEntryGuardsAsDirectoryGuards is enabled, we try to make sure
we have at least NUM routers to use as directory guards. If this
option is set to 0, use the value from the NumDirectoryGuards
consensus parameter, falling back to the value from NumEntryGuards
if the consensus parameter is 0 or isn't set. (Default: 0)
GuardLifetime N days|weeks|months
If nonzero, and UseEntryGuards is set, minimum time to keep a guard
before picking a new one. If zero, we use the GuardLifetime
parameter from the consensus directory. No value here may be less
than 1 month or greater than 5 years; out-of-range values are
clamped. (Default: 0)
SafeSocks 0|1
When this option is enabled, Tor will reject application
connections that use unsafe variants of the socks protocol --- ones
that only provide an IP address, meaning the application is doing a
DNS resolve first. Specifically, these are socks4 and socks5 when
not doing remote DNS. (Default: 0)
TestSocks 0|1
When this option is enabled, Tor will make a notice-level log entry
for each connection to the Socks port indicating whether the
request used a safe socks protocol or an unsafe one (see above
entry on SafeSocks). This helps to determine whether an application
using Tor is possibly leaking DNS requests. (Default: 0)
WarnUnsafeSocks 0|1
When this option is enabled, Tor will warn whenever a request is
received that only contains an IP address instead of a hostname.
Allowing applications to do DNS resolves themselves is usually a
bad idea and can leak your location to attackers. (Default: 1)
VirtualAddrNetworkIPv4 Address/bits
VirtualAddrNetworkIPv6 [Address]/bits
When Tor needs to assign a virtual (unused) address because of a
MAPADDRESS command from the controller or the AutomapHostsOnResolve
feature, Tor picks an unassigned address from this range.
(Defaults: 127.192.0.0/10 and [FE80::]/10 respectively.)
When providing proxy server service to a network of computers using
a tool like dns-proxy-tor, change the IPv4 network to
"10.192.0.0/10" or "172.16.0.0/12" and change the IPv6 network to
"[FC00::]/7". The default VirtualAddrNetwork address ranges on a
properly configured machine will route to the loopback or
link-local interface. The maximum number of bits for the network
prefix is set to 104 for IPv6 and 16 for IPv4. However, a wider
network - smaller prefix length
* is preferable since it reduces the chances for an attacker to
guess the used IP. For local use, no change to the default
VirtualAddrNetwork setting is needed.
AllowNonRFC953Hostnames 0|1
When this option is disabled, Tor blocks hostnames containing
illegal characters (like @ and :) rather than sending them to an
exit node to be resolved. This helps trap accidental attempts to
resolve URLs and so on. (Default: 0)
AllowDotExit 0|1
If enabled, we convert "www.google.com.foo.exit" addresses on the
SocksPort/TransPort/NATDPort into "www.google.com" addresses that
exit from the node "foo". Disabled by default since attacking
websites and exit relays can use it to manipulate your path
selection. (Default: 0)
FastFirstHopPK 0|1|auto
When this option is disabled, Tor uses the public key step for the
first hop of creating circuits. Skipping it is generally safe since
we have already used TLS to authenticate the relay and to establish
forward-secure keys. Turning this option off makes circuit building
a little slower. Setting this option to "auto" takes advice from
the authorities in the latest consensus about whether to use this
feature.
Note that Tor will always use the public key step for the first hop
if it's operating as a relay, and it will never use the public key
step if it doesn't yet know the onion key of the first hop.
(Default: auto)
TransPort [address:]port|auto [isolation flags]
Open this port to listen for transparent proxy connections. Set
this to 0 if you don't want to allow transparent proxy connections.
Set the port to "auto" to have Tor pick a port for you. This
directive can be specified multiple times to bind to multiple
addresses/ports. See SOCKSPort for an explanation of isolation
flags.
TransPort requires OS support for transparent proxies, such as
BSDs' pf or Linux's IPTables. If you're planning to use Tor as a
transparent proxy for a network, you'll want to examine and change
VirtualAddrNetwork from the default setting. You'll also want to
set the TransListenAddress option for the network you'd like to
proxy. (Default: 0)
TransListenAddress IP[:PORT]
Bind to this address to listen for transparent proxy connections.
(Default: 127.0.0.1). This is useful for exporting a transparent
proxy server to an entire network. (DEPRECATED: As of
0.2.3.x-alpha, you can now use multiple TransPort entries, and
provide addresses for TransPort entries, so TransListenAddress no
longer has a purpose. For backward compatibility,
TransListenAddress is only allowed when TransPort is just a port
number.)
TransProxyType default|TPROXY|ipfw|pf-divert
TransProxyType may only be enabled when there is transparent proxy
listener enabled.
Set this to "TPROXY" if you wish to be able to use the TPROXY Linux
module to transparently proxy connections that are configured using
the TransPort option. This setting lets the listener on the
TransPort accept connections for all addresses, even when the
TransListenAddress is configured for an internal address. Detailed
information on how to configure the TPROXY feature can be found in
the Linux kernel source tree in the file
Documentation/networking/tproxy.txt.
Set this option to "ipfw" to use the FreeBSD ipfw interface.
On *BSD operating systems when using pf, set this to "pf-divert" to
take advantage of divert-to rules, which do not modify the packets
like rdr-to rules do. Detailed information on how to configure pf
to use divert-to rules can be found in the pf.conf(5) manual page.
On OpenBSD, divert-to is available to use on versions greater than
or equal to OpenBSD 4.4.
Set this to "default", or leave it unconfigured, to use regular
IPTables on Linux, or to use pf rdr-to rules on *BSD systems.
(Default: "default".)
NATDPort [address:]port|auto [isolation flags]
Open this port to listen for connections from old versions of ipfw
(as included in old versions of FreeBSD, etc) using the NATD
protocol. Use 0 if you don't want to allow NATD connections. Set
the port to "auto" to have Tor pick a port for you. This directive
can be specified multiple times to bind to multiple
addresses/ports. See SocksPort for an explanation of isolation
flags.
This option is only for people who cannot use TransPort. (Default:
0)
NATDListenAddress IP[:PORT]
Bind to this address to listen for NATD connections. (DEPRECATED:
As of 0.2.3.x-alpha, you can now use multiple NATDPort entries, and
provide addresses for NATDPort entries, so NATDListenAddress no
longer has a purpose. For backward compatibility, NATDListenAddress
is only allowed when NATDPort is just a port number.)
AutomapHostsOnResolve 0|1
When this option is enabled, and we get a request to resolve an
address that ends with one of the suffixes in AutomapHostsSuffixes,
we map an unused virtual address to that address, and return the
new virtual address. This is handy for making ".onion" addresses
work with applications that resolve an address and then connect to
it. (Default: 0)
AutomapHostsSuffixes SUFFIX,SUFFIX,...
A comma-separated list of suffixes to use with
AutomapHostsOnResolve. The "." suffix is equivalent to "all
addresses." (Default: .exit,.onion).
DNSPort [address:]port|auto [isolation flags]
If non-zero, open this port to listen for UDP DNS requests, and
resolve them anonymously. This port only handles A, AAAA, and PTR
requests---it doesn't handle arbitrary DNS request types. Set the
port to "auto" to have Tor pick a port for you. This directive can
be specified multiple times to bind to multiple addresses/ports.
See SocksPort for an explanation of isolation flags. (Default: 0)
DNSListenAddress IP[:PORT]
Bind to this address to listen for DNS connections. (DEPRECATED: As
of 0.2.3.x-alpha, you can now use multiple DNSPort entries, and
provide addresses for DNSPort entries, so DNSListenAddress no
longer has a purpose. For backward compatibility, DNSListenAddress
is only allowed when DNSPort is just a port number.)
ClientDNSRejectInternalAddresses 0|1
If true, Tor does not believe any anonymously retrieved DNS answer
that tells it that an address resolves to an internal address (like
127.0.0.1 or 192.168.0.1). This option prevents certain
browser-based attacks; don't turn it off unless you know what
you're doing. (Default: 1)
ClientRejectInternalAddresses 0|1
If true, Tor does not try to fulfill requests to connect to an
internal address (like 127.0.0.1 or 192.168.0.1) unless a exit node
is specifically requested (for example, via a .exit hostname, or a
controller request). (Default: 1)
DownloadExtraInfo 0|1
If true, Tor downloads and caches "extra-info" documents. These
documents contain information about servers other than the
information in their regular server descriptors. Tor does not use
this information for anything itself; to save bandwidth, leave this
option turned off. (Default: 0)
WarnPlaintextPorts port,port,...
Tells Tor to issue a warnings whenever the user tries to make an
anonymous connection to one of these ports. This option is designed
to alert users to services that risk sending passwords in the
clear. (Default: 23,109,110,143)
RejectPlaintextPorts port,port,...
Like WarnPlaintextPorts, but instead of warning about risky port
uses, Tor will instead refuse to make the connection. (Default:
None)
AllowSingleHopCircuits 0|1
When this option is set, the attached Tor controller can use relays
that have the AllowSingleHopExits option turned on to build one-hop
Tor connections. (Default: 0)
OptimisticData 0|1|auto
When this option is set, and Tor is using an exit node that
supports the feature, it will try optimistically to send data to
the exit node without waiting for the exit node to report whether
the connection succeeded. This can save a round-trip time for
protocols like HTTP where the client talks first. If OptimisticData
is set to auto, Tor will look at the UseOptimisticData parameter in
the networkstatus. (Default: auto)
Tor2webMode 0|1
When this option is set, Tor connects to hidden services
non-anonymously. This option also disables client connections to
non-hidden-service hostnames through Tor. It must only be used when
running a tor2web Hidden Service web proxy. To enable this option
the compile time flag --enable-tor2web-mode must be specified.
Since Tor2webMode is non-anonymous, you can not run an anonymous
Hidden Service on a tor version compiled with Tor2webMode.
(Default: 0)
Tor2webRendezvousPoints node,node,...
A list of identity fingerprints, nicknames, country codes and
address patterns of nodes that are allowed to be used as RPs in HS
circuits; any other nodes will not be used as RPs. (Example:
Tor2webRendezvousPoints Fastyfasty,
ABCD1234CDEF5678ABCD1234CDEF5678ABCD1234, {cc}, 255.254.0.0/8)
This feature can only be used if Tor2webMode is also enabled.
ExcludeNodes have higher priority than Tor2webRendezvousPoints,
which means that nodes specified in ExcludeNodes will not be picked
as RPs.
If no nodes in Tor2webRendezvousPoints are currently available for
use, Tor will choose a random node when building HS circuits.
UseMicrodescriptors 0|1|auto
Microdescriptors are a smaller version of the information that Tor
needs in order to build its circuits. Using microdescriptors makes
Tor clients download less directory information, thus saving
bandwidth. Directory caches need to fetch regular descriptors and
microdescriptors, so this option doesn't save any bandwidth for
them. If this option is set to "auto" (recommended) then it is on
for all clients that do not set FetchUselessDescriptors. (Default:
auto)
PathBiasCircThreshold NUM
PathBiasNoticeRate NUM
PathBiasWarnRate NUM
PathBiasExtremeRate NUM
PathBiasDropGuards NUM
PathBiasScaleThreshold NUM
These options override the default behavior of Tor's (currently
experimental) path bias detection algorithm. To try to find broken
or misbehaving guard nodes, Tor looks for nodes where more than a
certain fraction of circuits through that guard fail to get built.
The PathBiasCircThreshold option controls how many circuits we need
to build through a guard before we make these checks. The
PathBiasNoticeRate, PathBiasWarnRate and PathBiasExtremeRate
options control what fraction of circuits must succeed through a
guard so we won't write log messages. If less than
PathBiasExtremeRate circuits succeed and PathBiasDropGuards is set
to 1, we disable use of that guard.
When we have seen more than PathBiasScaleThreshold circuits through
a guard, we scale our observations by 0.5 (governed by the
consensus) so that new observations don't get swamped by old ones.
By default, or if a negative value is provided for one of these
options, Tor uses reasonable defaults from the networkstatus
consensus document. If no defaults are available there, these
options default to 150, .70, .50, .30, 0, and 300 respectively.
PathBiasUseThreshold NUM
PathBiasNoticeUseRate NUM
PathBiasExtremeUseRate NUM
PathBiasScaleUseThreshold NUM
Similar to the above options, these options override the default
behavior of Tor's (currently experimental) path use bias detection
algorithm.
Where as the path bias parameters govern thresholds for
successfully building circuits, these four path use bias parameters
govern thresholds only for circuit usage. Circuits which receive no
stream usage are not counted by this detection algorithm. A used
circuit is considered successful if it is capable of carrying
streams or otherwise receiving well-formed responses to RELAY
cells.
By default, or if a negative value is provided for one of these
options, Tor uses reasonable defaults from the networkstatus
consensus document. If no defaults are available there, these
options default to 20, .80, .60, and 100, respectively.
ClientUseIPv4 0|1
If this option is set to 0, Tor will avoid connecting to directory
servers and entry nodes over IPv4. Note that clients with an IPv4
address in a Bridge, proxy, or pluggable transport line will try
connecting over IPv4 even if ClientUseIPv4 is set to 0. (Default:
1)
ClientUseIPv6 0|1
If this option is set to 1, Tor might connect to directory servers
or entry nodes over IPv6. Note that clients configured with an IPv6
address in a Bridge, proxy, or pluggable transport line will try
connecting over IPv6 even if ClientUseIPv6 is set to 0. (Default:
0)
ClientPreferIPv6DirPort 0|1|auto
If this option is set to 1, Tor prefers a directory port with an
IPv6 address over one with IPv4, for direct connections, if a given
directory server has both. (Tor also prefers an IPv6 DirPort if
IPv4Client is set to 0.) If this option is set to auto, clients
prefer IPv4. Other things may influence the choice. This option
breaks a tie to the favor of IPv6. (Default: auto)
ClientPreferIPv6ORPort 0|1|auto
If this option is set to 1, Tor prefers an OR port with an IPv6
address over one with IPv4 if a given entry node has both. (Tor
also prefers an IPv6 ORPort if IPv4Client is set to 0.) If this
option is set to auto, Tor bridge clients prefer the configured
bridge address, and other clients prefer IPv4. Other things may
influence the choice. This option breaks a tie to the favor of
IPv6. (Default: auto)
PathsNeededToBuildCircuits NUM
Tor clients don't build circuits for user traffic until they know
about enough of the network so that they could potentially
construct enough of the possible paths through the network. If this
option is set to a fraction between 0.25 and 0.95, Tor won't build
circuits until it has enough descriptors or microdescriptors to
construct that fraction of possible paths. Note that setting this
option too low can make your Tor client less anonymous, and setting
it too high can prevent your Tor client from bootstrapping. If this
option is negative, Tor will use a default value chosen by the
directory authorities. If the directory authorities do not choose a
value, Tor will default to 0.6. (Default: -1.)
ClientBootstrapConsensusAuthorityDownloadSchedule N,N,...
Schedule for when clients should download consensuses from
authorities if they are bootstrapping (that is, they don't have a
usable, reasonably live consensus). Only used by clients fetching
from a list of fallback directory mirrors. This schedule is
advanced by (potentially concurrent) connection attempts, unlike
other schedules, which are advanced by connection failures.
(Default: 10, 11, 3600, 10800, 25200, 54000, 111600, 262800)
ClientBootstrapConsensusFallbackDownloadSchedule N,N,...
Schedule for when clients should download consensuses from fallback
directory mirrors if they are bootstrapping (that is, they don't
have a usable, reasonably live consensus). Only used by clients
fetching from a list of fallback directory mirrors. This schedule
is advanced by (potentially concurrent) connection attempts, unlike
other schedules, which are advanced by connection failures.
(Default: 0, 1, 4, 11, 3600, 10800, 25200, 54000, 111600, 262800)
ClientBootstrapConsensusAuthorityOnlyDownloadSchedule N,N,...
Schedule for when clients should download consensuses from
authorities if they are bootstrapping (that is, they don't have a
usable, reasonably live consensus). Only used by clients which
don't have or won't fetch from a list of fallback directory
mirrors. This schedule is advanced by (potentially concurrent)
connection attempts, unlike other schedules, which are advanced by
connection failures. (Default: 0, 3, 7, 3600, 10800, 25200, 54000,
111600, 262800)
ClientBootstrapConsensusMaxDownloadTries NUM
Try this many times to download a consensus while bootstrapping
using fallback directory mirrors before giving up. (Default: 7)
ClientBootstrapConsensusAuthorityOnlyMaxDownloadTries NUM
Try this many times to download a consensus while bootstrapping
using authorities before giving up. (Default: 4)
ClientBootstrapConsensusMaxInProgressTries NUM
Try this many simultaneous connections to download a consensus
before waiting for one to complete, timeout, or error out.
(Default: 4)
SERVER OPTIONS
The following options are useful only for servers (that is, if ORPort
is non-zero):
Address address
The IP address or fully qualified domain name of this server (e.g.
moria.mit.edu). You can leave this unset, and Tor will guess your
IP address. This IP address is the one used to tell clients and
other servers where to find your Tor server; it doesn't affect the
IP that your Tor client binds to. To bind to a different address,
use the *ListenAddress and OutboundBindAddress options.
AllowSingleHopExits 0|1
This option controls whether clients can use this server as a
single hop proxy. If set to 1, clients can use this server as an
exit even if it is the only hop in the circuit. Note that most
clients will refuse to use servers that set this option, since most
clients have ExcludeSingleHopRelays set. (Default: 0)
AssumeReachable 0|1
This option is used when bootstrapping a new Tor network. If set to
1, don't do self-reachability testing; just upload your server
descriptor immediately. If AuthoritativeDirectory is also set, this
option instructs the dirserver to bypass remote reachability
testing too and list all connected servers as running.
BridgeRelay 0|1
Sets the relay to act as a "bridge" with respect to relaying
connections from bridge users to the Tor network. It mainly causes
Tor to publish a server descriptor to the bridge database, rather
than to the public directory authorities.
ContactInfo email_address
Administrative contact information for this relay or bridge. This
line can be used to contact you if your relay or bridge is
misconfigured or something else goes wrong. Note that we archive
and publish all descriptors containing these lines and that Google
indexes them, so spammers might also collect them. You may want to
obscure the fact that it's an email address and/or generate a new
address for this purpose.
ExitRelay 0|1|auto
Tells Tor whether to run as an exit relay. If Tor is running as a
non-bridge server, and ExitRelay is set to 1, then Tor allows
traffic to exit according to the ExitPolicy option (or the default
ExitPolicy if none is specified).
If ExitRelay is set to 0, no traffic is allowed to exit, and the
ExitPolicy option is ignored.
If ExitRelay is set to "auto", then Tor behaves as if it were set
to 1, but warns the user if this would cause traffic to exit. In a
future version, the default value will be 0. (Default: auto)
ExitPolicy policy,policy,...
Set an exit policy for this server. Each policy is of the form
"accept[6]|reject[6] ADDR[/MASK][:PORT]". If /MASK is omitted then
this policy just applies to the host given. Instead of giving a
host or network you can also use "*" to denote the universe
(0.0.0.0/0 and ::/128), or *4 to denote all IPv4 addresses, and *6
to denote all IPv6 addresses. PORT can be a single port number, an
interval of ports "FROM_PORT-TO_PORT", or "*". If PORT is omitted,
that means "*".
For example, "accept 18.7.22.69:*,reject 18.0.0.0/8:*,accept *:*"
would reject any IPv4 traffic destined for MIT except for
web.mit.edu, and accept any other IPv4 or IPv6 traffic.
Tor also allows IPv6 exit policy entries. For instance, "reject6
[FC00::]/7:*" rejects all destinations that share 7 most
significant bit prefix with address FC00::. Respectively, "accept6
[C000::]/3:*" accepts all destinations that share 3 most
significant bit prefix with address C000::.
accept6 and reject6 only produce IPv6 exit policy entries. Using an
IPv4 address with accept6 or reject6 is ignored and generates a
warning. accept/reject allows either IPv4 or IPv6 addresses. Use *4
as an IPv4 wildcard address, and *6 as an IPv6 wildcard address.
accept/reject * expands to matching IPv4 and IPv6 wildcard address
rules.
To specify all IPv4 and IPv6 internal and link-local networks
(including 0.0.0.0/8, 169.254.0.0/16, 127.0.0.0/8, 192.168.0.0/16,
10.0.0.0/8, 172.16.0.0/12, [::]/8, [FC00::]/7, [FE80::]/10,
[FEC0::]/10, [FF00::]/8, and [::]/127), you can use the "private"
alias instead of an address. ("private" always produces rules for
IPv4 and IPv6 addresses, even when used with accept6/reject6.)
Private addresses are rejected by default (at the beginning of your
exit policy), along with any configured primary public IPv4 and
IPv6 addresses. These private addresses are rejected unless you set
the ExitPolicyRejectPrivate config option to 0. For example, once
you've done that, you could allow HTTP to 127.0.0.1 and block all
other connections to internal networks with "accept
127.0.0.1:80,reject private:*", though that may also allow
connections to your own computer that are addressed to its public
(external) IP address. See RFC 1918 and RFC 3330 for more details
about internal and reserved IP address space. See
ExitPolicyRejectLocalInterfaces if you want to block every address
on the relay, even those that aren't advertised in the descriptor.
This directive can be specified multiple times so you don't have to
put it all on one line.
Policies are considered first to last, and the first match wins. If
you want to allow the same ports on IPv4 and IPv6, write your rules
using accept/reject *. If you want to allow different ports on IPv4
and IPv6, write your IPv6 rules using accept6/reject6 *6, and your
IPv4 rules using accept/reject *4. If you want to _replace_ the
default exit policy, end your exit policy with either a reject *:*
or an accept *:*. Otherwise, you're _augmenting_ (prepending to)
the default exit policy. The default exit policy is:
reject *:25
reject *:119
reject *:135-139
reject *:445
reject *:563
reject *:1214
reject *:4661-4666
reject *:6346-6429
reject *:6699
reject *:6881-6999
accept *:*
Since the default exit policy uses accept/reject *, it applies to both
IPv4 and IPv6 addresses.
ExitPolicyRejectPrivate 0|1
Reject all private (local) networks, along with the relay's
advertised public IPv4 and IPv6 addresses, at the beginning of your
exit policy. See above entry on ExitPolicy. (Default: 1)
ExitPolicyRejectLocalInterfaces 0|1
Reject all IPv4 and IPv6 addresses that the relay knows about, at
the beginning of your exit policy. This includes any
OutboundBindAddress, the bind addresses of any port options, such
as ControlPort or DNSPort, and any public IPv4 and IPv6 addresses
on any interface on the relay. (If IPv6Exit is not set, all IPv6
addresses will be rejected anyway.) See above entry on ExitPolicy.
This option is off by default, because it lists all public relay IP
addresses in the ExitPolicy, even those relay operators might
prefer not to disclose. (Default: 0)
IPv6Exit 0|1
If set, and we are an exit node, allow clients to use us for IPv6
traffic. (Default: 0)
MaxOnionQueueDelay NUM [msec|second]
If we have more onionskins queued for processing than we can
process in this amount of time, reject new ones. (Default: 1750
msec)
MyFamily node,node,...
Declare that this Tor server is controlled or administered by a
group or organization identical or similar to that of the other
servers, defined by their identity fingerprints. When two servers
both declare that they are in the same 'family', Tor clients will
not use them in the same circuit. (Each server only needs to list
the other servers in its family; it doesn't need to list itself,
but it won't hurt.) Do not list any bridge relay as it would
compromise its concealment.
When listing a node, it's better to list it by fingerprint than by
nickname: fingerprints are more reliable.
Nickname name
Set the server's nickname to 'name'. Nicknames must be between 1
and 19 characters inclusive, and must contain only the characters
[a-zA-Z0-9].
NumCPUs num
How many processes to use at once for decrypting onionskins and
other parallelizable operations. If this is set to 0, Tor will try
to detect how many CPUs you have, defaulting to 1 if it can't tell.
(Default: 0)
ORPort [address:]PORT|auto [flags]
Advertise this port to listen for connections from Tor clients and
servers. This option is required to be a Tor server. Set it to
"auto" to have Tor pick a port for you. Set it to 0 to not run an
ORPort at all. This option can occur more than once. (Default: 0)
Tor recognizes these flags on each ORPort:
**NoAdvertise**::
By default, we bind to a port and tell our users about it. If
NoAdvertise is specified, we don't advertise, but listen anyway. This
can be useful if the port everybody will be connecting to (for
example, one that's opened on our firewall) is somewhere else.
**NoListen**::
By default, we bind to a port and tell our users about it. If
NoListen is specified, we don't bind, but advertise anyway. This
can be useful if something else (for example, a firewall's port
forwarding configuration) is causing connections to reach us.
**IPv4Only**::
If the address is absent, or resolves to both an IPv4 and an IPv6
address, only listen to the IPv4 address.
**IPv6Only**::
If the address is absent, or resolves to both an IPv4 and an IPv6
address, only listen to the IPv6 address.
For obvious reasons, NoAdvertise and NoListen are mutually exclusive, and
IPv4Only and IPv6Only are mutually exclusive.
ORListenAddress IP[:PORT]
Bind to this IP address to listen for connections from Tor clients
and servers. If you specify a port, bind to this port rather than
the one specified in ORPort. (Default: 0.0.0.0) This directive can
be specified multiple times to bind to multiple addresses/ports.
This option is deprecated; you can get the same behavior with ORPort now
that it supports NoAdvertise and explicit addresses.
PortForwarding 0|1
Attempt to automatically forward the DirPort and ORPort on a NAT
router connecting this Tor server to the Internet. If set, Tor will
try both NAT-PMP (common on Apple routers) and UPnP (common on
routers from other manufacturers). (Default: 0)
PortForwardingHelper filename|pathname
If PortForwarding is set, use this executable to configure the
forwarding. If set to a filename, the system path will be searched
for the executable. If set to a path, only the specified path will
be executed. (Default: tor-fw-helper)
PublishServerDescriptor 0|1|v3|bridge,...
This option specifies which descriptors Tor will publish when
acting as a relay. You can choose multiple arguments, separated by
commas.
If this option is set to 0, Tor will not publish its descriptors to
any directories. (This is useful if you're testing out your server,
or if you're using a Tor controller that handles directory
publishing for you.) Otherwise, Tor will publish its descriptors of
all type(s) specified. The default is "1", which means "if running
as a server, publish the appropriate descriptors to the
authorities".
ShutdownWaitLength NUM
When we get a SIGINT and we're a server, we begin shutting down: we
close listeners and start refusing new circuits. After NUM seconds,
we exit. If we get a second SIGINT, we exit immediately. (Default:
30 seconds)
SSLKeyLifetime N minutes|hours|days|weeks
When creating a link certificate for our outermost SSL handshake,
set its lifetime to this amount of time. If set to 0, Tor will
choose some reasonable random defaults. (Default: 0)
HeartbeatPeriod N minutes|hours|days|weeks
Log a heartbeat message every HeartbeatPeriod seconds. This is a
log level notice message, designed to let you know your Tor server
is still alive and doing useful things. Settings this to 0 will
disable the heartbeat. Otherwise, it must be at least 30 minutes.
(Default: 6 hours)
AccountingMax N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits|TBytes
Limits the max number of bytes sent and received within a set time
period using a given calculation rule (see: AccountingStart,
AccountingRule). Useful if you need to stay under a specific
bandwidth. By default, the number used for calculation is the max
of either the bytes sent or received. For example, with
AccountingMax set to 1 GByte, a server could send 900 MBytes and
receive 800 MBytes and continue running. It will only hibernate
once one of the two reaches 1 GByte. This can be changed to use the
sum of the both bytes received and sent by setting the
AccountingRule option to "sum" (total bandwidth in/out). When the
number of bytes remaining gets low, Tor will stop accepting new
connections and circuits. When the number of bytes is exhausted,
Tor will hibernate until some time in the next accounting period.
To prevent all servers from waking at the same time, Tor will also
wait until a random point in each period before waking up. If you
have bandwidth cost issues, enabling hibernation is preferable to
setting a low bandwidth, since it provides users with a collection
of fast servers that are up some of the time, which is more useful
than a set of slow servers that are always "available".
AccountingRule sum|max|in|out
How we determine when our AccountingMax has been reached (when we
should hibernate) during a time interval. Set to "max" to calculate
using the higher of either the sent or received bytes (this is the
default functionality). Set to "sum" to calculate using the sent
plus received bytes. Set to "in" to calculate using only the
received bytes. Set to "out" to calculate using only the sent
bytes. (Default: max)
AccountingStart day|week|month [day] HH:MM
Specify how long accounting periods last. If month is given, each
accounting period runs from the time HH:MM on the dayth day of one
month to the same day and time of the next. (The day must be
between 1 and 28.) If week is given, each accounting period runs
from the time HH:MM of the dayth day of one week to the same day
and time of the next week, with Monday as day 1 and Sunday as day
7. If day is given, each accounting period runs from the time HH:MM
each day to the same time on the next day. All times are local, and
given in 24-hour time. (Default: "month 1 0:00")
RefuseUnknownExits 0|1|auto
Prevent nodes that don't appear in the consensus from exiting using
this relay. If the option is 1, we always block exit attempts from
such nodes; if it's 0, we never do, and if the option is "auto",
then we do whatever the authorities suggest in the consensus (and
block if the consensus is quiet on the issue). (Default: auto)
ServerDNSResolvConfFile filename
Overrides the default DNS configuration with the configuration in
filename. The file format is the same as the standard Unix
"resolv.conf" file (7). This option, like all other ServerDNS
options, only affects name lookups that your server does on behalf
of clients. (Defaults to use the system DNS configuration.)
ServerDNSAllowBrokenConfig 0|1
If this option is false, Tor exits immediately if there are
problems parsing the system DNS configuration or connecting to
nameservers. Otherwise, Tor continues to periodically retry the
system nameservers until it eventually succeeds. (Default: 1)
ServerDNSSearchDomains 0|1
If set to 1, then we will search for addresses in the local search
domain. For example, if this system is configured to believe it is
in "example.com", and a client tries to connect to "www", the
client will be connected to "www.example.com". This option only
affects name lookups that your server does on behalf of clients.
(Default: 0)
ServerDNSDetectHijacking 0|1
When this option is set to 1, we will test periodically to
determine whether our local nameservers have been configured to
hijack failing DNS requests (usually to an advertising site). If
they are, we will attempt to correct this. This option only affects
name lookups that your server does on behalf of clients. (Default:
1)
ServerDNSTestAddresses address,address,...
When we're detecting DNS hijacking, make sure that these valid
addresses aren't getting redirected. If they are, then our DNS is
completely useless, and we'll reset our exit policy to "reject
*:*". This option only affects name lookups that your server does
on behalf of clients. (Default: "www.google.com, www.mit.edu,
www.yahoo.com, www.slashdot.org")
ServerDNSAllowNonRFC953Hostnames 0|1
When this option is disabled, Tor does not try to resolve hostnames
containing illegal characters (like @ and :) rather than sending
them to an exit node to be resolved. This helps trap accidental
attempts to resolve URLs and so on. This option only affects name
lookups that your server does on behalf of clients. (Default: 0)
BridgeRecordUsageByCountry 0|1
When this option is enabled and BridgeRelay is also enabled, and we
have GeoIP data, Tor keeps a per-country count of how many client
addresses have contacted it so that it can help the bridge
authority guess which countries have blocked access to it.
(Default: 1)
ServerDNSRandomizeCase 0|1
When this option is set, Tor sets the case of each character
randomly in outgoing DNS requests, and makes sure that the case
matches in DNS replies. This so-called "0x20 hack" helps resist
some types of DNS poisoning attack. For more information, see
"Increased DNS Forgery Resistance through 0x20-Bit Encoding". This
option only affects name lookups that your server does on behalf of
clients. (Default: 1)
GeoIPFile filename
A filename containing IPv4 GeoIP data, for use with by-country
statistics.
GeoIPv6File filename
A filename containing IPv6 GeoIP data, for use with by-country
statistics.
TLSECGroup P224|P256
What EC group should we try to use for incoming TLS connections?
P224 is faster, but makes us stand out more. Has no effect if we're
a client, or if our OpenSSL version lacks support for ECDHE.
(Default: P256)
CellStatistics 0|1
Relays only. When this option is enabled, Tor collects statistics
about cell processing (i.e. mean time a cell is spending in a
queue, mean number of cells in a queue and mean number of processed
cells per circuit) and writes them into disk every 24 hours. Onion
router operators may use the statistics for performance monitoring.
If ExtraInfoStatistics is enabled, it will published as part of
extra-info document. (Default: 0)
DirReqStatistics 0|1
Relays and bridges only. When this option is enabled, a Tor
directory writes statistics on the number and response time of
network status requests to disk every 24 hours. Enables relay and
bridge operators to monitor how much their server is being used by
clients to learn about Tor network. If ExtraInfoStatistics is
enabled, it will published as part of extra-info document.
(Default: 1)
EntryStatistics 0|1
Relays only. When this option is enabled, Tor writes statistics on
the number of directly connecting clients to disk every 24 hours.
Enables relay operators to monitor how much inbound traffic that
originates from Tor clients passes through their server to go
further down the Tor network. If ExtraInfoStatistics is enabled, it
will be published as part of extra-info document. (Default: 0)
ExitPortStatistics 0|1
Exit relays only. When this option is enabled, Tor writes
statistics on the number of relayed bytes and opened stream per
exit port to disk every 24 hours. Enables exit relay operators to
measure and monitor amounts of traffic that leaves Tor network
through their exit node. If ExtraInfoStatistics is enabled, it will
be published as part of extra-info document. (Default: 0)
ConnDirectionStatistics 0|1
Relays only. When this option is enabled, Tor writes statistics on
the amounts of traffic it passes between itself and other relays to
disk every 24 hours. Enables relay operators to monitor how much
their relay is being used as middle node in the circuit. If
ExtraInfoStatistics is enabled, it will be published as part of
extra-info document. (Default: 0)
HiddenServiceStatistics 0|1
Relays only. When this option is enabled, a Tor relay writes
obfuscated statistics on its role as hidden-service directory,
introduction point, or rendezvous point to disk every 24 hours. If
ExtraInfoStatistics is also enabled, these statistics are further
published to the directory authorities. (Default: 1)
ExtraInfoStatistics 0|1
When this option is enabled, Tor includes previously gathered
statistics in its extra-info documents that it uploads to the
directory authorities. (Default: 1)
ExtendAllowPrivateAddresses 0|1
When this option is enabled, Tor will connect to relays on
localhost, RFC1918 addresses, and so on. In particular, Tor will
make direct OR connections, and Tor routers allow EXTEND requests,
to these private addresses. (Tor will always allow connections to
bridges, proxies, and pluggable transports configured on private
addresses.) Enabling this option can create security issues; you
should probably leave it off. (Default: 0)
MaxMemInQueues N bytes|KB|MB|GB
This option configures a threshold above which Tor will assume that
it needs to stop queueing or buffering data because it's about to
run out of memory. If it hits this threshold, it will begin killing
circuits until it has recovered at least 10% of this memory. Do not
set this option too low, or your relay may be unreliable under
load. This option only affects some queues, so the actual process
size will be larger than this. If this option is set to 0, Tor will
try to pick a reasonable default based on your system's physical
memory. (Default: 0)
DisableOOSCheck 0|1
This option disables the code that closes connections when Tor
notices that it is running low on sockets. Right now, it is on by
default, since the existing out-of-sockets mechanism tends to kill
OR connections more than it should. (Default: 1)
SigningKeyLifetime N days|weeks|months
For how long should each Ed25519 signing key be valid? Tor uses a
permanent master identity key that can be kept offline, and
periodically generates new "signing" keys that it uses online. This
option configures their lifetime. (Default: 30 days)
OfflineMasterKey 0|1
If non-zero, the Tor relay will never generate or load its master
secret key. Instead, you'll have to use "tor --keygen" to manage
the permanent ed25519 master identity key, as well as the
corresponding temporary signing keys and certificates. (Default: 0)
DIRECTORY SERVER OPTIONS
The following options are useful only for directory servers (that is,
if DirPort is non-zero):
DirPortFrontPage FILENAME
When this option is set, it takes an HTML file and publishes it as
"/" on the DirPort. Now relay operators can provide a disclaimer
without needing to set up a separate webserver. There's a sample
disclaimer in contrib/operator-tools/tor-exit-notice.html.
DirPort [address:]PORT|auto [flags]
If this option is nonzero, advertise the directory service on this
port. Set it to "auto" to have Tor pick a port for you. This option
can occur more than once, but only one advertised DirPort is
supported: all but one DirPort must have the NoAdvertise flag set.
(Default: 0)
The same flags are supported here as are supported by ORPort.
DirListenAddress IP[:PORT]
Bind the directory service to this address. If you specify a port,
bind to this port rather than the one specified in DirPort.
(Default: 0.0.0.0) This directive can be specified multiple times
to bind to multiple addresses/ports.
This option is deprecated; you can get the same behavior with DirPort now
that it supports NoAdvertise and explicit addresses.
DirPolicy policy,policy,...
Set an entrance policy for this server, to limit who can connect to
the directory ports. The policies have the same form as exit
policies above, except that port specifiers are ignored. Any
address not matched by some entry in the policy is accepted.
DirCache 0|1
When this option is set, Tor caches all current directory documents
and accepts client requests for them. Setting DirPort is not
required for this, because clients connect via the ORPort by
default. Setting either DirPort or BridgeRelay and setting DirCache
to 0 is not supported. (Default: 1)
DIRECTORY AUTHORITY SERVER OPTIONS
The following options enable operation as a directory authority, and
control how Tor behaves as a directory authority. You should not need
to adjust any of them if you're running a regular relay or exit server
on the public Tor network.
AuthoritativeDirectory 0|1
When this option is set to 1, Tor operates as an authoritative
directory server. Instead of caching the directory, it generates
its own list of good servers, signs it, and sends that to the
clients. Unless the clients already have you listed as a trusted
directory, you probably do not want to set this option.
V3AuthoritativeDirectory 0|1
When this option is set in addition to AuthoritativeDirectory, Tor
generates version 3 network statuses and serves descriptors, etc as
described in dir-spec.txt file of torspec (for Tor clients and
servers running at least 0.2.0.x).
VersioningAuthoritativeDirectory 0|1
When this option is set to 1, Tor adds information on which
versions of Tor are still believed safe for use to the published
directory. Each version 1 authority is automatically a versioning
authority; version 2 authorities provide this service optionally.
See RecommendedVersions, RecommendedClientVersions, and
RecommendedServerVersions.
RecommendedVersions STRING
STRING is a comma-separated list of Tor versions currently believed
to be safe. The list is included in each directory, and nodes which
pull down the directory learn whether they need to upgrade. This
option can appear multiple times: the values from multiple lines
are spliced together. When this is set then
VersioningAuthoritativeDirectory should be set too.
RecommendedPackages PACKAGENAME VERSION URL DIGESTTYPE=DIGEST
Adds "package" line to the directory authority's vote. This
information is used to vote on the correct URL and digest for the
released versions of different Tor-related packages, so that the
consensus can certify them. This line may appear any number of
times.
RecommendedClientVersions STRING
STRING is a comma-separated list of Tor versions currently believed
to be safe for clients to use. This information is included in
version 2 directories. If this is not set then the value of
RecommendedVersions is used. When this is set then
VersioningAuthoritativeDirectory should be set too.
BridgeAuthoritativeDir 0|1
When this option is set in addition to AuthoritativeDirectory, Tor
accepts and serves server descriptors, but it caches and serves the
main networkstatus documents rather than generating its own.
(Default: 0)
MinUptimeHidServDirectoryV2 N seconds|minutes|hours|days|weeks
Minimum uptime of a v2 hidden service directory to be accepted as
such by authoritative directories. (Default: 25 hours)
RecommendedServerVersions STRING
STRING is a comma-separated list of Tor versions currently believed
to be safe for servers to use. This information is included in
version 2 directories. If this is not set then the value of
RecommendedVersions is used. When this is set then
VersioningAuthoritativeDirectory should be set too.
ConsensusParams STRING
STRING is a space-separated list of key=value pairs that Tor will
include in the "params" line of its networkstatus vote.
DirAllowPrivateAddresses 0|1
If set to 1, Tor will accept server descriptors with arbitrary
"Address" elements. Otherwise, if the address is not an IP address
or is a private IP address, it will reject the server descriptor.
Additionally, Tor will allow exit policies for private networks to
fulfill Exit flag requirements. (Default: 0)
AuthDirBadExit AddressPattern...
Authoritative directories only. A set of address patterns for
servers that will be listed as bad exits in any network status
document this authority publishes, if AuthDirListBadExits is set.
(The address pattern syntax here and in the options below is the
same as for exit policies, except that you don't need to say
"accept" or "reject", and ports are not needed.)
AuthDirInvalid AddressPattern...
Authoritative directories only. A set of address patterns for
servers that will never be listed as "valid" in any network status
document that this authority publishes.
AuthDirReject AddressPattern...
Authoritative directories only. A set of address patterns for
servers that will never be listed at all in any network status
document that this authority publishes, or accepted as an OR
address in any descriptor submitted for publication by this
authority.
AuthDirBadExitCCs CC,...
AuthDirInvalidCCs CC,...
AuthDirRejectCCs CC,...
Authoritative directories only. These options contain a
comma-separated list of country codes such that any server in one
of those country codes will be marked as a bad exit/invalid for
use, or rejected entirely.
AuthDirListBadExits 0|1
Authoritative directories only. If set to 1, this directory has
some opinion about which nodes are unsuitable as exit nodes. (Do
not set this to 1 unless you plan to list non-functioning exits as
bad; otherwise, you are effectively voting in favor of every
declared exit as an exit.)
AuthDirMaxServersPerAddr NUM
Authoritative directories only. The maximum number of servers that
we will list as acceptable on a single IP address. Set this to "0"
for "no limit". (Default: 2)
AuthDirMaxServersPerAuthAddr NUM
Authoritative directories only. Like AuthDirMaxServersPerAddr, but
applies to addresses shared with directory authorities. (Default:
5)
AuthDirFastGuarantee N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
Authoritative directories only. If non-zero, always vote the Fast
flag for any relay advertising this amount of capacity or more.
(Default: 100 KBytes)
AuthDirGuardBWGuarantee N bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
Authoritative directories only. If non-zero, this advertised
capacity or more is always sufficient to satisfy the bandwidth
requirement for the Guard flag. (Default: 250 KBytes)
AuthDirPinKeys 0|1
Authoritative directories only. If non-zero, do not allow any relay
to publish a descriptor if any other relay has reserved its
<Ed25519,RSA> identity keypair. In all cases, Tor records every
keypair it accepts in a journal if it is new, or if it differs from
the most recently accepted pinning for one of the keys it contains.
(Default: 0)
AuthDirSharedRandomness 0|1
Authoritative directories only. Switch for the shared random
protocol. If zero, the authority won't participate in the protocol.
If non-zero (default), the flag "shared-rand-participate" is added
to the authority vote indicating participation in the protocol.
(Default: 1)
BridgePassword Password
If set, contains an HTTP authenticator that tells a bridge
authority to serve all requested bridge information. Used by the
(only partially implemented) "bridge community" design, where a
community of bridge relay operators all use an alternate bridge
directory authority, and their target user audience can
periodically fetch the list of available community bridges to stay
up-to-date. (Default: not set)
V3AuthVotingInterval N minutes|hours
V3 authoritative directories only. Configures the server's
preferred voting interval. Note that voting will actually happen at
an interval chosen by consensus from all the authorities' preferred
intervals. This time SHOULD divide evenly into a day. (Default: 1
hour)
V3AuthVoteDelay N minutes|hours
V3 authoritative directories only. Configures the server's
preferred delay between publishing its vote and assuming it has all
the votes from all the other authorities. Note that the actual time
used is not the server's preferred time, but the consensus of all
preferences. (Default: 5 minutes)
V3AuthDistDelay N minutes|hours
V3 authoritative directories only. Configures the server's
preferred delay between publishing its consensus and signature and
assuming it has all the signatures from all the other authorities.
Note that the actual time used is not the server's preferred time,
but the consensus of all preferences. (Default: 5 minutes)
V3AuthNIntervalsValid NUM
V3 authoritative directories only. Configures the number of
VotingIntervals for which each consensus should be valid for.
Choosing high numbers increases network partitioning risks;
choosing low numbers increases directory traffic. Note that the
actual number of intervals used is not the server's preferred
number, but the consensus of all preferences. Must be at least 2.
(Default: 3)
V3BandwidthsFile FILENAME
V3 authoritative directories only. Configures the location of the
bandwidth-authority generated file storing information on relays'
measured bandwidth capacities. (Default: unset)
V3AuthUseLegacyKey 0|1
If set, the directory authority will sign consensuses not only with
its own signing key, but also with a "legacy" key and certificate
with a different identity. This feature is used to migrate
directory authority keys in the event of a compromise. (Default: 0)
RephistTrackTime N seconds|minutes|hours|days|weeks
Tells an authority, or other node tracking node reliability and
history, that fine-grained information about nodes can be discarded
when it hasn't changed for a given amount of time. (Default: 24
hours)
AuthDirHasIPv6Connectivity 0|1
Authoritative directories only. When set to 0, OR ports with an
IPv6 address are being accepted without reachability testing. When
set to 1, IPv6 OR ports are being tested just like IPv4 OR ports.
(Default: 0)
MinMeasuredBWsForAuthToIgnoreAdvertised N
A total value, in abstract bandwidth units, describing how much
measured total bandwidth an authority should have observed on the
network before it will treat advertised bandwidths as wholly
unreliable. (Default: 500)
HIDDEN SERVICE OPTIONS
The following options are used to configure a hidden service.
HiddenServiceDir DIRECTORY
Store data files for a hidden service in DIRECTORY. Every hidden
service must have a separate directory. You may use this option
multiple times to specify multiple services. DIRECTORY must be an
existing directory. (Note: in current versions of Tor, if DIRECTORY
is a relative path, it will be relative to current working
directory of Tor instance, not to its DataDirectory. Do not rely on
this behavior; it is not guaranteed to remain the same in future
versions.)
HiddenServicePort VIRTPORT [TARGET]
Configure a virtual port VIRTPORT for a hidden service. You may use
this option multiple times; each time applies to the service using
the most recent HiddenServiceDir. By default, this option maps the
virtual port to the same port on 127.0.0.1 over TCP. You may
override the target port, address, or both by specifying a target
of addr, port, addr:port, or unix:path. (You can specify an IPv6
target as [addr]:port. Unix paths may be quoted, and may use
standard C escapes.) You may also have multiple lines with the same
VIRTPORT: when a user connects to that VIRTPORT, one of the TARGETs
from those lines will be chosen at random.
PublishHidServDescriptors 0|1
If set to 0, Tor will run any hidden services you configure, but it
won't advertise them to the rendezvous directory. This option is
only useful if you're using a Tor controller that handles hidserv
publishing for you. (Default: 1)
HiddenServiceVersion version,version,...
A list of rendezvous service descriptor versions to publish for the
hidden service. Currently, only version 2 is supported. (Default:
2)
HiddenServiceAuthorizeClient auth-type client-name,client-name,...
If configured, the hidden service is accessible for authorized
clients only. The auth-type can either be 'basic' for a
general-purpose authorization protocol or 'stealth' for a less
scalable protocol that also hides service activity from
unauthorized clients. Only clients that are listed here are
authorized to access the hidden service. Valid client names are 1
to 16 characters long and only use characters in A-Za-z0-9+-_ (no
spaces). If this option is set, the hidden service is not
accessible for clients without authorization any more. Generated
authorization data can be found in the hostname file. Clients need
to put this authorization data in their configuration file using
HidServAuth.
HiddenServiceAllowUnknownPorts 0|1
If set to 1, then connections to unrecognized ports do not cause
the current hidden service to close rendezvous circuits. (Setting
this to 0 is not an authorization mechanism; it is instead meant to
be a mild inconvenience to port-scanners.) (Default: 0)
HiddenServiceMaxStreams N
The maximum number of simultaneous streams (connections) per
rendezvous circuit. (Setting this to 0 will allow an unlimited
number of simultanous streams.) (Default: 0)
HiddenServiceMaxStreamsCloseCircuit 0|1
If set to 1, then exceeding HiddenServiceMaxStreams will cause the
offending rendezvous circuit to be torn down, as opposed to stream
creation requests that exceed the limit being silently ignored.
(Default: 0)
RendPostPeriod N seconds|minutes|hours|days|weeks
Every time the specified period elapses, Tor uploads any rendezvous
service descriptors to the directory servers. This information is
also uploaded whenever it changes. (Default: 1 hour)
HiddenServiceDirGroupReadable 0|1
If this option is set to 1, allow the filesystem group to read the
hidden service directory and hostname file. If the option is set to
0, only owner is able to read the hidden service directory.
(Default: 0) Has no effect on Windows.
HiddenServiceNumIntroductionPoints NUM
Number of introduction points the hidden service will have. You
can't have more than 10. (Default: 3)
HiddenServiceSingleHopMode 0|1
Experimental - Non Anonymous Hidden Services on a tor instance in
HiddenServiceSingleHopMode make one-hop (direct) circuits between
the onion service server, and the introduction and rendezvous
points. (Onion service descriptors are still posted using 3-hop
paths, to avoid onion service directories blocking the service.)
This option makes every hidden service instance hosted by a tor
instance a Single Onion Service. One-hop circuits make Single Onion
servers easily locatable, but clients remain location-anonymous.
However, the fact that a client is accessing a Single Onion rather
than a Hidden Service may be statistically distinguishable.
**WARNING:** Once a hidden service directory has been used by a tor
instance in HiddenServiceSingleHopMode, it can **NEVER** be used again for
a hidden service. It is best practice to create a new hidden service
directory, key, and address for each new Single Onion Service and Hidden
Service. It is not possible to run Single Onion Services and Hidden
Services from the same tor instance: they should be run on different
servers with different IP addresses.
HiddenServiceSingleHopMode requires HiddenServiceNonAnonymousMode to be set
to 1. Since a Single Onion service is non-anonymous, you can not configure
a SOCKSPort on a tor instance that is running in
**HiddenServiceSingleHopMode**.
(Default: 0)
HiddenServiceNonAnonymousMode 0|1
Makes hidden services non-anonymous on this tor instance. Allows
the non-anonymous HiddenServiceSingleHopMode. Enables direct
connections in the server-side hidden service protocol. If you are
using this option, you need to disable all client-side services on
your Tor instance, including setting SOCKSPort to "0". (Default: 0)
TESTING NETWORK OPTIONS
The following options are used for running a testing Tor network.
TestingTorNetwork 0|1
If set to 1, Tor adjusts default values of the configuration
options below, so that it is easier to set up a testing Tor
network. May only be set if non-default set of DirAuthorities is
set. Cannot be unset while Tor is running. (Default: 0)
ServerDNSAllowBrokenConfig 1
DirAllowPrivateAddresses 1
EnforceDistinctSubnets 0
AssumeReachable 1
AuthDirMaxServersPerAddr 0
AuthDirMaxServersPerAuthAddr 0
ClientBootstrapConsensusAuthorityDownloadSchedule 0, 2,
4 (for 40 seconds), 8, 16, 32, 60
ClientBootstrapConsensusFallbackDownloadSchedule 0, 1,
4 (for 40 seconds), 8, 16, 32, 60
ClientBootstrapConsensusAuthorityOnlyDownloadSchedule 0, 1,
4 (for 40 seconds), 8, 16, 32, 60
ClientBootstrapConsensusMaxDownloadTries 80
ClientBootstrapConsensusAuthorityOnlyMaxDownloadTries 80
ClientDNSRejectInternalAddresses 0
ClientRejectInternalAddresses 0
CountPrivateBandwidth 1
ExitPolicyRejectPrivate 0
ExtendAllowPrivateAddresses 1
V3AuthVotingInterval 5 minutes
V3AuthVoteDelay 20 seconds
V3AuthDistDelay 20 seconds
MinUptimeHidServDirectoryV2 0 seconds
TestingV3AuthInitialVotingInterval 5 minutes
TestingV3AuthInitialVoteDelay 20 seconds
TestingV3AuthInitialDistDelay 20 seconds
TestingAuthDirTimeToLearnReachability 0 minutes
TestingEstimatedDescriptorPropagationTime 0 minutes
TestingServerDownloadSchedule 0, 0, 0, 5, 10, 15, 20, 30, 60
TestingClientDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
TestingServerConsensusDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
TestingClientConsensusDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
TestingBridgeDownloadSchedule 60, 30, 30, 60
TestingClientMaxIntervalWithoutRequest 5 seconds
TestingDirConnectionMaxStall 30 seconds
TestingConsensusMaxDownloadTries 80
TestingDescriptorMaxDownloadTries 80
TestingMicrodescMaxDownloadTries 80
TestingCertMaxDownloadTries 80
TestingEnableConnBwEvent 1
TestingEnableCellStatsEvent 1
TestingEnableTbEmptyEvent 1
TestingV3AuthInitialVotingInterval N minutes|hours
Like V3AuthVotingInterval, but for initial voting interval before
the first consensus has been created. Changing this requires that
TestingTorNetwork is set. (Default: 30 minutes)
TestingV3AuthInitialVoteDelay N minutes|hours
Like V3AuthVoteDelay, but for initial voting interval before the
first consensus has been created. Changing this requires that
TestingTorNetwork is set. (Default: 5 minutes)
TestingV3AuthInitialDistDelay N minutes|hours
Like V3AuthDistDelay, but for initial voting interval before the
first consensus has been created. Changing this requires that
TestingTorNetwork is set. (Default: 5 minutes)
TestingV3AuthVotingStartOffset N seconds|minutes|hours
Directory authorities offset voting start time by this much.
Changing this requires that TestingTorNetwork is set. (Default: 0)
TestingAuthDirTimeToLearnReachability N minutes|hours
After starting as an authority, do not make claims about whether
routers are Running until this much time has passed. Changing this
requires that TestingTorNetwork is set. (Default: 30 minutes)
TestingEstimatedDescriptorPropagationTime N minutes|hours
Clients try downloading server descriptors from directory caches
after this time. Changing this requires that TestingTorNetwork is
set. (Default: 10 minutes)
TestingMinFastFlagThreshold N
bytes|KBytes|MBytes|GBytes|KBits|MBits|GBits
Minimum value for the Fast flag. Overrides the ordinary minimum
taken from the consensus when TestingTorNetwork is set. (Default:
0.)
TestingServerDownloadSchedule N,N,...
Schedule for when servers should download things in general.
Changing this requires that TestingTorNetwork is set. (Default: 0,
0, 0, 60, 60, 120, 300, 900, 2147483647)
TestingClientDownloadSchedule N,N,...
Schedule for when clients should download things in general.
Changing this requires that TestingTorNetwork is set. (Default: 0,
0, 60, 300, 600, 2147483647)
TestingServerConsensusDownloadSchedule N,N,...
Schedule for when servers should download consensuses. Changing
this requires that TestingTorNetwork is set. (Default: 0, 0, 60,
300, 600, 1800, 1800, 1800, 1800, 1800, 3600, 7200)
TestingClientConsensusDownloadSchedule N,N,...
Schedule for when clients should download consensuses. Changing
this requires that TestingTorNetwork is set. (Default: 0, 0, 60,
300, 600, 1800, 3600, 3600, 3600, 10800, 21600, 43200)
TestingBridgeDownloadSchedule N,N,...
Schedule for when clients should download bridge descriptors.
Changing this requires that TestingTorNetwork is set. (Default:
3600, 900, 900, 3600)
TestingClientMaxIntervalWithoutRequest N seconds|minutes
When directory clients have only a few descriptors to request, they
batch them until they have more, or until this amount of time has
passed. Changing this requires that TestingTorNetwork is set.
(Default: 10 minutes)
TestingDirConnectionMaxStall N seconds|minutes
Let a directory connection stall this long before expiring it.
Changing this requires that TestingTorNetwork is set. (Default: 5
minutes)
TestingConsensusMaxDownloadTries NUM
Try this many times to download a consensus before giving up.
Changing this requires that TestingTorNetwork is set. (Default: 8)
TestingDescriptorMaxDownloadTries NUM
Try this often to download a server descriptor before giving up.
Changing this requires that TestingTorNetwork is set. (Default: 8)
TestingMicrodescMaxDownloadTries NUM
Try this often to download a microdesc descriptor before giving up.
Changing this requires that TestingTorNetwork is set. (Default: 8)
TestingCertMaxDownloadTries NUM
Try this often to download a v3 authority certificate before giving
up. Changing this requires that TestingTorNetwork is set. (Default:
8)
TestingDirAuthVoteExit node,node,...
A list of identity fingerprints, country codes, and address
patterns of nodes to vote Exit for regardless of their uptime,
bandwidth, or exit policy. See the ExcludeNodes option for more
information on how to specify nodes.
In order for this option to have any effect, TestingTorNetwork has
to be set. See the ExcludeNodes option for more information on how
to specify nodes.
TestingDirAuthVoteExitIsStrict 0|1
If True (1), a node will never receive the Exit flag unless it is
specified in the TestingDirAuthVoteExit list, regardless of its
uptime, bandwidth, or exit policy.
In order for this option to have any effect, TestingTorNetwork has
to be set.
TestingDirAuthVoteGuard node,node,...
A list of identity fingerprints and country codes and address
patterns of nodes to vote Guard for regardless of their uptime and
bandwidth. See the ExcludeNodes option for more information on how
to specify nodes.
In order for this option to have any effect, TestingTorNetwork has
to be set.
TestingDirAuthVoteGuardIsStrict 0|1
If True (1), a node will never receive the Guard flag unless it is
specified in the TestingDirAuthVoteGuard list, regardless of its
uptime and bandwidth.
In order for this option to have any effect, TestingTorNetwork has
to be set.
TestingDirAuthVoteHSDir node,node,...
A list of identity fingerprints and country codes and address
patterns of nodes to vote HSDir for regardless of their uptime and
DirPort. See the ExcludeNodes option for more information on how to
specify nodes.
In order for this option to have any effect, TestingTorNetwork must
be set.
TestingDirAuthVoteHSDirIsStrict 0|1
If True (1), a node will never receive the HSDir flag unless it is
specified in the TestingDirAuthVoteHSDir list, regardless of its
uptime and DirPort.
In order for this option to have any effect, TestingTorNetwork has
to be set.
TestingEnableConnBwEvent 0|1
If this option is set, then Tor controllers may register for
CONN_BW events. Changing this requires that TestingTorNetwork is
set. (Default: 0)
TestingEnableCellStatsEvent 0|1
If this option is set, then Tor controllers may register for
CELL_STATS events. Changing this requires that TestingTorNetwork is
set. (Default: 0)
TestingEnableTbEmptyEvent 0|1
If this option is set, then Tor controllers may register for
TB_EMPTY events. Changing this requires that TestingTorNetwork is
set. (Default: 0)
TestingMinExitFlagThreshold N KBytes|MBytes|GBytes|KBits|MBits|GBits
Sets a lower-bound for assigning an exit flag when running as an
authority on a testing network. Overrides the usual default lower
bound of 4 KB. (Default: 0)
TestingLinkCertLifetime N seconds|minutes|hours|days|weeks|months
Overrides the default lifetime for the certificates used to
authenticate our X509 link cert with our ed25519 signing key.
(Default: 2 days)
TestingAuthKeyLifetime N seconds|minutes|hours|days|weeks|months
Overrides the default lifetime for a signing Ed25519 TLS Link
authentication key. (Default: 2 days)
TestingLinkKeySlop N seconds|minutes|hours
TestingAuthKeySlop N seconds|minutes|hours
TestingSigningKeySlop N seconds|minutes|hours
How early before the official expiration of a an Ed25519 signing
key do we replace it and issue a new key? (Default: 3 hours for
link and auth; 1 day for signing.)
SIGNALS
Tor catches the following signals:
SIGTERM
Tor will catch this, clean up and sync to disk if necessary, and
exit.
SIGINT
Tor clients behave as with SIGTERM; but Tor servers will do a
controlled slow shutdown, closing listeners and waiting 30 seconds
before exiting. (The delay can be configured with the
ShutdownWaitLength config option.)
SIGHUP
The signal instructs Tor to reload its configuration (including
closing and reopening logs), and kill and restart its helper
processes if applicable.
SIGUSR1
Log statistics about current connections, past connections, and
throughput.
SIGUSR2
Switch all logs to loglevel debug. You can go back to the old
loglevels by sending a SIGHUP.
SIGCHLD
Tor receives this signal when one of its helper processes has
exited, so it can clean up.
SIGPIPE
Tor catches this signal and ignores it.
SIGXFSZ
If this signal exists on your platform, Tor catches and ignores it.
FILES
/etc/tor/torrc
The configuration file, which contains "option value" pairs.
$HOME/.torrc
Fallback location for torrc, if /etc/tor/torrc is not found.
/var/lib/tor/
The tor process stores keys and other data here.
DataDirectory/cached-status/
The most recently downloaded network status document for each
authority. Each file holds one such document; the filenames are the
hexadecimal identity key fingerprints of the directory authorities.
Mostly obsolete.
DataDirectory/cached-certs
This file holds downloaded directory key certificates that are used
to verify authenticity of documents generated by Tor directory
authorities.
DataDirectory/cached-consensus and/or cached-microdesc-consensus
The most recent consensus network status document we've downloaded.
DataDirectory/cached-descriptors and cached-descriptors.new
These files hold downloaded router statuses. Some routers may
appear more than once; if so, the most recently published
descriptor is used. Lines beginning with @-signs are annotations
that contain more information about a given router. The ".new" file
is an append-only journal; when it gets too large, all entries are
merged into a new cached-descriptors file.
DataDirectory/cached-microdescs and cached-microdescs.new
These files hold downloaded microdescriptors. Lines beginning with
@-signs are annotations that contain more information about a given
router. The ".new" file is an append-only journal; when it gets too
large, all entries are merged into a new cached-microdescs file.
DataDirectory/cached-routers and cached-routers.new
Obsolete versions of cached-descriptors and cached-descriptors.new.
When Tor can't find the newer files, it looks here instead.
DataDirectory/state
A set of persistent key-value mappings. These are documented in the
file. These include:
* The current entry guards and their status.
* The current bandwidth accounting values (unused so far; see
below).
* When the file was last written
* What version of Tor generated the state file
* A short history of bandwidth usage, as produced in the server
descriptors.
DataDirectory/bw_accounting
Used to track bandwidth accounting values (when the current period
starts and ends; how much has been read and written so far this
period). This file is obsolete, and the data is now stored in the
'state' file as well. Only used when bandwidth accounting is
enabled.
DataDirectory/control_auth_cookie
Used for cookie authentication with the controller. Location can be
overridden by the CookieAuthFile config option. Regenerated on
startup. See control-spec.txt in torspec for details. Only used
when cookie authentication is enabled.
DataDirectory/lock
This file is used to prevent two Tor instances from using same data
directory. If access to this file is locked, data directory is
already in use by Tor.
DataDirectory/keys/*
Only used by servers. Holds identity keys and onion keys.
DataDirectory/keys/authority_identity_key
A v3 directory authority's master identity key, used to
authenticate its signing key. Tor doesn't use this while it's
running. The tor-gencert program uses this. If you're running an
authority, you should keep this key offline, and not actually put
it here.
DataDirectory/keys/authority_certificate
A v3 directory authority's certificate, which authenticates the
authority's current vote- and consensus-signing key using its
master identity key. Only directory authorities use this file.
DataDirectory/keys/authority_signing_key
A v3 directory authority's signing key, used to sign votes and
consensuses. Only directory authorities use this file. Corresponds
to the authority_certificate cert.
DataDirectory/keys/legacy_certificate
As authority_certificate: used only when V3AuthUseLegacyKey is set.
See documentation for V3AuthUseLegacyKey.
DataDirectory/keys/legacy_signing_key
As authority_signing_key: used only when V3AuthUseLegacyKey is set.
See documentation for V3AuthUseLegacyKey.
DataDirectory/keys/secret_id_key
A relay's RSA1024 permanent identity key, including private and
public components. Used to sign router descriptors, and to sign
other keys.
DataDirectory/keys/ed25519_master_id_public_key
The public part of a relay's Ed25519 permanent identity key.
DataDirectory/keys/ed25519_master_id_secret_key
The private part of a relay's Ed25519 permanent identity key. This
key is used to sign the medium-term ed25519 signing key. This file
can be kept offline, or kept encrypted. If so, Tor will not be able
to generate new signing keys itself; you'll need to use tor
--keygen yourself to do so.
DataDirectory/keys/ed25519_signing_secret_key
The private and public components of a relay's medium-term Ed25519
signing key. This key is authenticated by the Ed25519 master key,
in turn authenticates other keys (and router descriptors).
DataDirectory/keys/ed25519_signing_cert
The certificate which authenticates "ed25519_signing_secret_key" as
having been signed by the Ed25519 master key.
DataDirectory/keys/secret_onion_key
A relay's RSA1024 short-term onion key. Used to decrypt old-style
("TAP") circuit extension requests.
DataDirectory/keys/secret_onion_key_ntor
A relay's Curve25519 short-term onion key. Used to handle modern
("ntor") circuit extension requests.
DataDirectory/fingerprint
Only used by servers. Holds the fingerprint of the server's
identity key.
DataDirectory/hashed-fingerprint
Only used by bridges. Holds the hashed fingerprint of the bridge's
identity key. (That is, the hash of the hash of the identity key.)
DataDirectory/v3-status-votes
Only for v3 authoritative directory servers. This file contains
status votes from all the authoritative directory servers.
DataDirectory/unverified-consensus
This file contains a network consensus document that has been
downloaded, but which we didn't have the right certificates to
check yet.
DataDirectory/unverified-microdesc-consensus
This file contains a microdescriptor-flavored network consensus
document that has been downloaded, but which we didn't have the
right certificates to check yet.
DataDirectory/unparseable-desc
Onion server descriptors that Tor was unable to parse are dumped to
this file. Only used for debugging.
DataDirectory/router-stability
Only used by authoritative directory servers. Tracks measurements
for router mean-time-between-failures so that authorities have a
good idea of how to set their Stable flags.
DataDirectory/stats/dirreq-stats
Only used by directory caches and authorities. This file is used to
collect directory request statistics.
DataDirectory/stats/entry-stats
Only used by servers. This file is used to collect incoming
connection statistics by Tor entry nodes.
DataDirectory/stats/bridge-stats
Only used by servers. This file is used to collect incoming
connection statistics by Tor bridges.
DataDirectory/stats/exit-stats
Only used by servers. This file is used to collect outgoing
connection statistics by Tor exit routers.
DataDirectory/stats/buffer-stats
Only used by servers. This file is used to collect buffer usage
history.
DataDirectory/stats/conn-stats
Only used by servers. This file is used to collect approximate
connection history (number of active connections over time).
DataDirectory/networkstatus-bridges
Only used by authoritative bridge directories. Contains information
about bridges that have self-reported themselves to the bridge
authority.
HiddenServiceDirectory/hostname
The <base32-encoded-fingerprint>.onion domain name for this hidden
service. If the hidden service is restricted to authorized clients
only, this file also contains authorization data for all clients.
HiddenServiceDirectory/private_key
The private key for this hidden service.
HiddenServiceDirectory/client_keys
Authorization data for a hidden service that is only accessible by
authorized clients.
HiddenServiceDirectory/onion_service_non_anonymous
This file is present if a hidden service key was created in
HiddenServiceNonAnonymousMode.
SEE ALSO
torsocks(1), torify(1) https://www.torproject.org/ torspec: https://spec.torproject.org
BUGS
Plenty, probably. Tor is still in development. Please report them at https://trac.torproject.org/.
AUTHORS
Roger Dingledine [arma at mit.edu], Nick Mathewson [nickm at alum.mit.edu].
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