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. Each node in a virtual
circuit knows its predecessor and successor nodes, but no other nodes.
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, including web
traffic, ftp, ssh, etc., around the network, so that recipients, observers,
and even the relays themselves have difficulty tracking the source of the
stream.
Note
By default, tor acts as a client only. To help the network
by providing bandwidth as a relay, change the ORPort configuration
option as mentioned below. Please also consult the documentation on the Tor
Project’s website.
COMMAND-LINE OPTIONS¶
Tor has a powerful command-line interface. This section lists
optional arguments you can specify at the command line using the tor
command.
Configuration options can be specified on the command line in the
format --OptionName OptionValue, on the command line in
the format OptionName OptionValue, or in a configuration file.
For instance, you can tell Tor to start listening for SOCKS connections on
port 9999 by passing either --SocksPort 9999 or SocksPort 9999
on the command line, or by specifying SocksPort 9999 in the
configuration file. On the command line, quote option values that contain
spaces. For instance, if you want Tor to log all debugging messages to
debug.log, you must specify --Log "debug file
debug.log".
Note
Configuration options on the command line override those in
configuration files. See THE CONFIGURATION FILE FORMAT for more
information.
The following options in this section are only recognized on the
tor command line, not in a configuration file.
-h, --help
Display a short help message and exit.
-f, --torrc-file 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
Allow the configuration file specified by -f to be
missing, if the defaults-torrc file (see below) is accessible.
--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
Specify 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
Generate a hashed password for control port access.
--list-fingerprint [key type]
Generate your keys and output your nickname and
fingerprint. Optionally, you can specify the key type as rsa (default) or
ed25519.
--verify-config
Verify whether the configuration file is valid.
--dump-config short|full
Write a list of Tor’s configured options to
standard output. When the short flag is selected, only write the options that
are different from their default values. When full is selected, write every
option.
--service install [--options command-line
options]
--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.)
--list-modules
List whether each optional module has been compiled into
Tor. (Any module not listed is not optional in this version of Tor.)
--version
Display Tor version and exit. The output is a single line
of the format "Tor version [version number]." (The version number
format is as specified in version-spec.txt.)
--quiet|--hush
Override the default console logging behavior. 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. These options override the
default console logging behavior. Use the --hush option if you want Tor
to log only warnings and errors to the console, or use the --quiet
option if you want 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. When Tor asks you for a passphrase and
you don’t want to encrypt the master key, just don’t enter any
passphrase when asked.
Use the --newpass option 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 passphrase (if any), and the
new passphrase (if any).
Note
When generating a master key, you may want to use
--DataDirectory to
control where the keys and certificates will be stored, and
--SigningKeyLifetime to control their lifetimes. See SERVER OPTIONS to
learn more about the behavior of these options. 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
File descriptor 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. If the file
descriptor is not specified, the passphrase is read from the terminal by
default.
--key-expiration [purpose] [--format
iso8601|timestamp]
The
purpose specifies which type of key
certificate to determine the expiration of. The only currently recognised
purpose is "sign".
Running tor --key-expiration sign will attempt to find your
signing key certificate and will output, both in the logs as well as to
stdout. The optional --format argument lets you specify the time
format. Currently, iso8601 and timestamp are supported. If
--format is not specified, the signing key certificate’s
expiration time will be in ISO-8601 format. For example, the output sent to
stdout will be of the form: "signing-cert-expiry: 2017-07-25 08:30:15
UTC". If --format timestamp is specified, the signing key
certificate’s expiration time will be in Unix timestamp format. For
example, the output sent to stdout will be of the form:
"signing-cert-expiry: 1500971415".
--dbg-...
Tor may support other options beginning with the string
"dbg". These are intended for use by developers to debug and test
Tor. They are not supported or guaranteed to be stable, and you should
probably not use them.
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.
Configuration options can be imported from files or folders using
the %include option with the value being a path. This path can have
wildcards. Wildcards are expanded first, then sorted using lexical order.
Then, for each matching file or folder, the following rules are followed: if
the path is a file, the options from the file will be parsed as if they were
written where the %include option is. If the path is a folder, all files on
that folder will be parsed following lexical order. Files starting with a
dot are ignored. Files in subfolders are ignored. The %include option can be
used recursively. New configuration files or directories cannot be added to
already running Tor instance if Sandbox is enabled.
The supported wildcards are * meaning any number of characters
including none and ? meaning exactly one character. These characters can be
escaped by preceding them with a backslash, except on Windows. Files
starting with a dot are not matched when expanding wildcards unless the
starting dot is explicitly in the pattern, except on Windows.
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¶
AccelDir DIR
Specify this option if using dynamic hardware
acceleration and the engine implementation library resides somewhere other
than the OpenSSL default. Can not be changed while tor is running.
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. Can
not be changed while tor is running.
If the engine name is prefixed with a "!", then Tor will
exit if the engine cannot be loaded.
AlternateBridgeAuthority [nickname] [flags]
ipv4address:port fingerprint,
AlternateDirAuthority [nickname] [flags]
ipv4address: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.
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)
BandwidthBurst N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
Limit the maximum token bucket size (also known as the
burst) to the given number of bytes in each direction. (Default: 1
GByte)
BandwidthRate N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
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)
Note that this option, and other bandwidth-limiting options, apply
to TCP data only: They do not count TCP headers or DNS traffic.
Tor uses powers of two, not powers of ten, so 1 GByte is
1024*1024*1024 bytes as opposed to 1 billion bytes.
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. Case doesn’t matter. 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.
CacheDirectory DIR
Store cached directory data in DIR. Can not be changed
while tor is running. (Default: uses the value of DataDirectory.)
CacheDirectoryGroupReadable
0|1|auto
If this option is set to 0, don’t allow the
filesystem group to read the CacheDirectory. If the option is set to 1, make
the CacheDirectory readable by the default GID. If the option is
"auto", then we use the setting for DataDirectoryGroupReadable when
the CacheDirectory is the same as the DataDirectory, and 0 otherwise.
(Default: auto)
CircuitPriorityHalflife NUM
If this value is set, we override the default algorithm
for choosing which circuit’s cell to deliver or relay next. It is
delivered first to the circuit that has the lowest weighted cell count, where
cells are weighted exponentially according to this value (in seconds). If the
value is -1, it is taken from the consensus if possible else it will fallback
to the default value of 30. Minimum: 1, Maximum: 2147483647. This can be
defined as a float value. This is an advanced option; you generally
shouldn’t have to mess with it. (Default: -1)
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". (IPv4 addresses should written as-is; IPv6 addresses
should be wrapped in square brackets.) 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. (Default: none)
ConfluxEnabled 0|1|auto
If this option is set to 1, general purpose traffic will
use Conflux which is traffic splitting among multiple legs (circuits). Onion
services are not supported at the moment. Default value is set to
"auto" meaning the consensus is used to decide unless set. (Default:
auto)
ConfluxClientUX
throughput|latency|throughput_lowmem|latency_lowmem
This option configures the user experience that the
client requests from the exit, for data that the exit sends to the client. The
default is "throughput", which maximizes throughput.
"Latency" will tell the exit to only use the circuit with lower
latency for all data. The lowmem versions minimize queue usage memory at the
client. (Default: "throughput")
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.
Tor relays need thousands of sockets, to connect to every other
relay. If you are running a private bridge, you can reduce the number of
sockets that Tor uses. For example, to limit Tor to 500 sockets, run
"ulimit -n 500" in a shell. Then start tor in the same shell, with
ConnLimit 500. You may also need to set DisableOOSCheck 0.
Unless you have severely limited sockets, you probably
don’t need to adjust ConnLimit itself. It has no effect on
Windows, since that platform lacks getrlimit(). (Default: 1000)
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
[address:]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. You can specify this directive multiple times, to bind to multiple
address/port pairs. 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.
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)
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".
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.) (Default: 0)
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)
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.)
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)
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)
DataDirectory DIR
Store working data in DIR. Can not be changed while tor
is running. (Default: ~/.tor if your home directory is not /; otherwise,
/var/lib/tor. On Windows, the default is your ApplicationData folder.)
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)
DirAuthority [nickname] [flags]
ipv4address:dirport 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=orport" 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=[ipv6address]: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 ipv4address to download
directory documents. Clients always use the ORPort. Relays usually use the
DirPort, but will use the ORPort in some circumstances. If an IPv6 ORPort is
supplied, clients will also download directory documents at the IPv6 ORPort,
if they are configured to use IPv6.
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. The default is less than 1, to reduce load on authorities.
(Default: 0.1)
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.
Can not be changed while tor is running. (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)
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. Tor will
make still certain network-related calls (like DNS lookups) as a part of its
configuration process, even if DisableNetwork is set. (Default: 0)
ExtendByEd25519ID 0|1|auto
If this option is set to 1, we always try to include a
relay’s Ed25519 ID when telling the preceding relay in a circuit to
extend to it. If this option is set to 0, we never include Ed25519 IDs when
extending circuits. If the option is set to "auto", we obey a
parameter in the consensus document. (Default: auto)
ExtORPort
[address:]port|auto
Open this port to listen for Extended ORPort connections
from your pluggable transports.
(Default: DataDirectory/extended_orport_auth_cookie)
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)
FallbackDir ipv4address:dirport
orport=orport id=fingerprint [weight=num]
[ipv6=[ipv6address]:orport]
When tor is unable to connect to any directory cache for
directory info (usually because it doesn’t know about any yet) it tries
a hard-coded directory. Relays try one directory authority at a time. Clients
try multiple directory authorities and FallbackDirs, to avoid hangs on startup
if a hard-coded directory is down. Clients wait for a few seconds between each
attempt, and retry FallbackDirs more often than directory authorities, to
reduce the load on the directory authorities.
FallbackDirs should be stable relays with stable IP addresses,
ports, and identity keys. They must have a DirPort.
By default, the directory authorities are also FallbackDirs.
Specifying a FallbackDir replaces Tor’s default hard-coded
FallbackDirs (if any). (See DirAuthority for an explanation of each
flag.)
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 consensus flavor, and
all server descriptors and authority certificates referenced by those
consensuses, except for extra info descriptors. When this option is 1, Tor
will also keep fetching descriptors, even when idle. If set to 0, Tor will
avoid fetching useless descriptors: flavors that it is not using to build
circuits, and authority certificates it does not trust. When Tor hasn’t
built any application circuits, it will go idle, and stop fetching
descriptors. This option is useful if you’re using a tor client with an
external parser that uses a full consensus. This option fetches all documents
except extrainfo descriptors, DirCache fetches and serves all documents
except extrainfo descriptors, DownloadExtraInfo* fetches extrainfo
documents, and serves them if DirCache is on, and
UseMicrodescriptors changes the flavor of consensuses and descriptors
that is fetched and used for building circuits. (Default: 0)
HardwareAccel 0|1
If non-zero, try to use built-in (static) crypto hardware
acceleration when available. Can not be changed while tor is running.
(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.
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. (DEPRECATED: As of 0.3.1.0-alpha you should
use HTTPSProxy.)
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. (DEPRECATED: As of 0.3.1.0-alpha you should use
HTTPSProxyAuthenticator.)
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.
KeepalivePeriod NUM
To keep firewalls from expiring connections, send a
padding keepalive cell every NUM seconds on open connections that are in use.
(Default: 5 minutes)
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. Can not be changed while tor is running. (Default: auto.)
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.
Some low-level logs may be sent from signal handlers, so their
destination logs must be signal-safe. These low-level logs include
backtraces, logging function errors, and errors in code called by logging
functions. Signal-safe logs are always sent to stderr or stdout. They are
also sent to a limited number of log files that are configured to log
messages at error severity from the bug or general domains. They are never
sent as syslogs, control port log events, or to any API-based log
destinations.
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, handshake, heartbeat, channel, sched, guard, consdiff,
dos, process, pt, btrack, and mesg. 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)
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)
MaxAdvertisedBandwidth N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
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.
MaxUnparseableDescSizeToLog N
bytes|KBytes|MBytes|GBytes|TBytes
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
MBytes)
MetricsPort [address:]port
[format]
WARNING: Before enabling this, it is important to
understand that exposing tor metrics publicly is dangerous to the Tor network
users. Please take extra precaution and care when opening this port. Set a
very strict access policy with MetricsPortPolicy and consider using your
operating systems firewall features for defense in depth.
We recommend, for the prometheus format, that the only
address that can access this port should be the Prometheus server itself.
Remember that the connection is unencrypted (HTTP) hence consider using a
tool like stunnel to secure the link from this port to the server.
If set, open this port to listen for an HTTP GET request to
"/metrics". Upon a request, the collected metrics in the the tor
instance are formatted for the given format and then sent back. If this is
set, MetricsPortPolicy must be defined else every request will be
rejected.
Supported format is "prometheus" which is also the
default if not set. The Prometheus data model can be found here:
https://prometheus.io/docs/concepts/data_model/
The tor metrics are constantly collected and they solely consists
of counters. Thus, asking for those metrics is very lightweight on the tor
process. (Default: None)
As an example, here only 5.6.7.8 will be allowed to connect:
MetricsPort 1.2.3.4:9035
MetricsPortPolicy accept 5.6.7.8
MetricsPortPolicy
policy,policy,...
Set an entrance policy for the
MetricsPort, to
limit who can access it. The policies have the same form as exit policies
below, except that port specifiers are ignored. For multiple entries, this
line can be used multiple times. It is a reject all by default policy.
(Default: None)
Please, keep in mind here that if the server collecting metrics on
the MetricsPort is behind a NAT, then everything behind it can access it.
This is similar for the case of allowing localhost, every users on the
server will be able to access it. Again, strongly consider using a tool like
stunnel to secure the link or to strengthen access control.
NoExec 0|1
If this option is set to 1, then Tor will never launch
another executable, regardless of the settings of ClientTransportPlugin or
ServerTransportPlugin. Once this option has been set to 1, it cannot be set
back to 0 without restarting Tor. (Default: 0)
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. IPv6 addresses should be wrapped in square brackets.
This setting will be ignored for connections to the loopback addresses
(127.0.0.0/8 and ::1), and is not used for DNS requests as well.
OutboundBindAddressExit IP
Make all outbound exit connections originate from the IP
address specified. This option overrides OutboundBindAddress for the
same IP version. This option may be used twice, once with an IPv4 address and
once with an IPv6 address. IPv6 addresses should be wrapped in square
brackets. This setting will be ignored for connections to the loopback
addresses (127.0.0.0/8 and ::1).
OutboundBindAddressOR IP
Make all outbound non-exit (relay and other) connections
originate from the IP address specified. This option overrides
OutboundBindAddress for the same IP version. This option may be used
twice, once with an IPv4 address and once with an IPv6 address. IPv6 addresses
should be wrapped in square brackets. This setting will be ignored for
connections to the loopback addresses (127.0.0.0/8 and ::1).
__OwningControllerProcess PID
Make Tor instance periodically check for presence of a
controller process with given PID and terminate itself if this process is no
longer alive. Polling interval is 15 seconds.
PerConnBWBurst N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
If this option is set manually, or via the
"perconnbwburst" consensus field, Tor will use it for separate rate
limiting for each connection from a non-relay. (Default: 0)
PerConnBWRate N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
If this option is set manually, or via the
"perconnbwrate" consensus field, Tor will use it for separate rate
limiting for each connection from a non-relay. (Default: 0)
OutboundBindAddressPT IP
Request that pluggable transports makes all outbound
connections originate from the IP address specified. Because outgoing
connections are handled by the pluggable transport itself, it is not possible
for Tor to enforce whether the pluggable transport honors this option. This
option overrides OutboundBindAddress for the same IP version. This
option may be used twice, once with an IPv4 address and once with an IPv6
address. IPv6 addresses should be wrapped in square brackets. 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. Can not be changed while tor is running.
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)
RelayBandwidthBurst N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
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. They do not include directory fetches by the relay (from authority
or other relays), because that is considered "client" activity.
(Default: 0) RelayBandwidthBurst defaults to the value of RelayBandwidthRate
if unset.
RelayBandwidthRate N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
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. They do not
include directory fetches by the relay (from authority or other relays),
because that is considered "client" activity. (Default: 0)
RelayBandwidthRate defaults to the value of RelayBandwidthBurst if
unset.
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)
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. Can not be changed while tor is running. (Default:
0)
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. Note: Tor may
not heed this option when logging at log levels below Notice. (Default:
1)
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 only works
on Linux-based operating systems, and only when Tor has been built with the
libseccomp library. Note that this option may be incompatible with some
versions of libc, and some kernel versions. This option can not be changed
while tor is running.
When the Sandbox is 1, the following options can not be
changed when tor is running: Address, ConnLimit,
CookieAuthFile, DirPortFrontPage,
ExtORPortCookieAuthFile, Logs, ServerDNSResolvConfFile,
ClientOnionAuthDir (and any files in it won’t reload on HUP
signal).
Launching new Onion Services through the control port is not
supported with current syscall sandboxing implementation.
Tor must remain in client or server mode (some changes to
ClientOnly and ORPort are not allowed). Currently, if
Sandbox is 1, ControlPort command "GETINFO address"
will not work.
When using %include in the tor configuration files, reloading the
tor configuration is not supported after adding new configuration files or
directories.
(Default: 0)
Schedulers KIST|KISTLite|Vanilla
Specify the scheduler type that tor should use. The
scheduler is responsible for moving data around within a Tor process. This is
an ordered list by priority which means that the first value will be tried
first and if unavailable, the second one is tried and so on. It is possible to
change these values at runtime. This option mostly effects relays, and most
operators should leave it set to its default value. (Default:
KIST,KISTLite,Vanilla)
The possible scheduler types are:
KIST: Kernel-Informed Socket Transport. Tor will use TCP
information from the kernel to make informed decisions regarding how much
data to send and when to send it. KIST also handles traffic in batches (see
KISTSchedRunInterval) in order to improve traffic prioritization decisions.
As implemented, KIST will only work on Linux kernel version 2.6.39 or
higher.
KISTLite: Same as KIST but without kernel support. Tor will
use all the same mechanics as with KIST, including the batching, but its
decisions regarding how much data to send will not be as good. KISTLite will
work on all kernels and operating systems, and the majority of the benefits
of KIST are still realized with KISTLite.
Vanilla: The scheduler that Tor used before KIST was
implemented. It sends as much data as possible, as soon as possible. Vanilla
will work on all kernels and operating systems.
KISTSchedRunInterval NUM msec
If KIST or KISTLite is used in the Schedulers option,
this controls at which interval the scheduler tick is. If the value is 0 msec,
the value is taken from the consensus if possible else it will fallback to the
default 10 msec. Maximum possible value is 100 msec. (Default: 0 msec)
KISTSockBufSizeFactor NUM
If KIST is used in Schedulers, this is a multiplier of
the per-socket limit calculation of the KIST algorithm. (Default: 1.0)
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.
SyslogIdentityTag tag
When logging to syslog, adds a tag to the syslog identity
such that log entries are marked with "Tor-tag". Can not be
changed while tor is running. (Default: none)
TCPProxy protocol host:port
Tor will use the given protocol to make all its OR (SSL)
connections through a TCP proxy on host:port, 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 proxy only allows connecting to
certain ports. There is no equivalent option for directory connections,
because all Tor client versions that support this option download directory
documents via OR connections.
The only protocol supported right now 'haproxy'. This option is only for
clients. (Default: none) +
Both source IP address and source port will be set to zero.
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)
UnixSocksGroupWritable 0|1
If this option is set to 0, don’t allow the
filesystem group to read and write unix sockets (e.g. SocksPort unix:). If the
option is set to 1, make the Unix socket readable and writable by the default
GID. (Default: 0)
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)
User Username
On startup, setuid to this user and setgid to their
primary group. Can not be changed while tor is running.
CLIENT OPTIONS¶
The following options are useful only for clients (that is, if
SocksPort, HTTPTunnelPort, TransPort, DNSPort,
or NATDPort is non-zero):
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)
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).
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.
Tor passes any "key=val" settings to the pluggable
transport proxy as per-connection arguments when connecting to the bridge.
Consult the documentation of the pluggable transport for details of what
arguments it supports.
CircuitPadding 0|1
If set to 0, Tor will not pad client circuits with
additional cover traffic. Only clients may set this option. This option should
be offered via the UI to mobile users for use where bandwidth may be
expensive. If set to 1, padding will be negotiated as per the consensus and
relay support (unlike ConnectionPadding, CircuitPadding cannot be
force-enabled). (Default: 1)
ReducedCircuitPadding 0|1
If set to 1, Tor will only use circuit padding algorithms
that have low overhead. Only clients may set this option. This option should
be offered via the UI to mobile users for use where bandwidth may be
expensive. (Default: 0)
ClientBootstrapConsensusAuthorityDownloadInitialDelay
N
Initial delay in seconds 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: 6)
ClientBootstrapConsensusAuthorityOnlyDownloadInitialDelay
N
Initial delay in seconds 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)
ClientBootstrapConsensusFallbackDownloadInitialDelay
N
Initial delay in seconds 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)
ClientBootstrapConsensusMaxInProgressTries NUM
Try this many simultaneous connections to download a
consensus before waiting for one to complete, timeout, or error out. (Default:
3)
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;
it is not allowed to be set on the default network. (Default: 1)
ClientOnionAuthDir path
Path to the directory containing v3 hidden service
authorization files. Each file is for a single onion address, and the files
MUST have the suffix ".auth_private" (i.e.
"bob_onion.auth_private"). The content format MUST be:
<onion-address>:descriptor:x25519:<base32-encoded-privkey>
The <onion-address> MUST NOT have the ".onion"
suffix. The <base32-encoded-privkey> is the base32 representation of
the raw key bytes only (32 bytes for x25519). See Appendix G in the
rend-spec-v3.txt file of torspec for more information.
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)
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) (DEPRECATED: This option has had no effect for some
time.)
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)
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 an exit node
is specifically requested (for example, via a .exit hostname, or a
controller request). If true, multicast DNS hostnames for machines on the
local network (of the form *.local) are also rejected. (Default: 1)
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. For IPv6 only hosts, you need to
also set ClientUseIPv4 to 0 to disable IPv4. Note that clients
configured with an IPv6 address in a Bridge, proxy, or pluggable
transportline will try connecting over IPv6 even if ClientUseIPv6 is
set to 0. (Default: 1)
ConnectionPadding 0|1|auto
This option governs Tor’s use of padding to defend
against some forms of traffic analysis. If it is set to auto, Tor will
send padding only if both the client and the relay support it. If it is set to
0, Tor will not send any padding cells. If it is set to 1, Tor will still send
padding for client connections regardless of relay support. Only clients may
set this option. This option should be offered via the UI to mobile users for
use where bandwidth may be expensive. (Default: auto)
ReducedConnectionPadding 0|1
If set to 1, Tor will not not hold OR connections open
for very long, and will send less padding on these connections. Only clients
may set this option. This option should be offered via the UI to mobile users
for use where bandwidth may be expensive. (Default: 0)
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)
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)
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)
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)
HTTPTunnelPort
[address:]port|auto [isolation flags]
Open this port to listen for proxy connections using the
"HTTP CONNECT" protocol instead of SOCKS. Set this to 0 if you
don’t want to allow "HTTP CONNECT" 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. If multiple
entries of this option are present in your configuration file, Tor will
perform stream isolation between listeners by default. See SocksPort for an
explanation of isolation flags. (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". If the specified exit is
not available, or the exit can not connect to the site, Tor will fail any
connections to the mapped address.+
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
198.51.100.1:
MapAddress www.torproject.org 192.0.2.1
MapAddress www.torproject.org 198.51.100.1
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 203.0.113.1:
MapAddress 198.51.100.1 203.0.113.1
MapAddress www.torproject.org 198.51.100.1
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.
5.Tor maps hostnames and IP addresses separately. If you
MapAddress a DNS name, but use an IP address to connect, then Tor will ignore
the DNS name mapping.
6.MapAddress does not apply to redirects in the
application protocol. For example, HTTP redirects and alt-svc headers will
ignore mappings for the original address. You can use a wildcard mapping to
handle redirects within the same site.
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 also remain alive for
MaxCircuitDirtiness seconds after carrying the last such stream. (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)
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. If multiple
entries of this option are present in your configuration file, Tor will
perform stream isolation between listeners by default. See SocksPort for an
explanation of isolation flags.
This option is only for people who cannot use TransPort. (Default:
0)
NewCircuitPeriod NUM
Every NUM seconds consider whether to build a new
circuit. (Default: 30 seconds)
PathBiasCircThreshold NUM
PathBiasDropGuards NUM
PathBiasExtremeRate NUM
PathBiasNoticeRate NUM
PathBiasWarnRate 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.
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)
ReachableAddresses
IP[/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
IP[/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. (DEPRECATED: This option has had no
effect for some time.)
ReachableORAddresses
IP[/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.
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 SafeSocks). This helps to
determine whether an application using Tor is possibly leaking DNS requests.
(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)
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.
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. Most flags are off by default, except
where specified. Flags that are on by default can be disabled by putting
"No" before the flag name. (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.
If multiple entries of this option are present in your
configuration file, Tor will perform stream isolation between listeners by
default. 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. (For HTTPTunnelPort connections,
this option looks at the Proxy-Authorization and X-Tor-Stream-Isolation
headers. On by default; you can disable it with
NoIsolateSOCKSAuth.)
IsolateClientProtocol
Don’t share circuits with streams using a
different protocol. (SOCKS 4, SOCKS 5, HTTPTunnelPort connections, 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 while they have at least one stream with SOCKS authentication active.
After such a circuit is idle for more than MaxCircuitDirtiness seconds, it can
be closed.
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.
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, or
UseIPv6Cache or 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.
NoPreferIPv6Automap
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 IPv4 answer. (Tor prefers IPv6 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.
ExtendedErrors
Return extended error code in the SOCKS reply. So far,
the possible errors are:
X'F0' Onion Service Descriptor Can Not be Found
The requested onion service descriptor can't be found on the
hashring and thus not reachable by the client. (v3 only)
X'F1' Onion Service Descriptor Is Invalid
The requested onion service descriptor can't be parsed or
signature validation failed. (v3 only)
X'F2' Onion Service Introduction Failed
All introduction attempts failed either due to a combination of
NACK by the intro point or time out. (v3 only)
X'F3' Onion Service Rendezvous Failed
Every rendezvous circuit has timed out and thus the client is
unable to rendezvous with the service. (v3 only)
X'F4' Onion Service Missing Client Authorization
Client was able to download the requested onion service descriptor
but is unable to decrypt its content because it is missing client
authorization information. (v3 only)
X'F5' Onion Service Wrong Client Authorization
Client was able to download the requested onion service descriptor
but is unable to decrypt its content using the client
authorization information it has. This means the client access
were revoked. (v3 only)
X'F6' Onion Service Invalid Address
The given .onion address is invalid. In one of these cases this
error is returned: address checksum doesn't match, ed25519 public
key is invalid or the encoding is invalid. (v3 only)
X'F7' Onion Service Introduction Timed Out
Similar to X'F2' code but in this case, all introduction attempts
have failed due to a time out. (v3 only)
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.
TokenBucketRefillInterval NUM
[msec|second]
Set the refill delay interval of Tor’s token
bucket to NUM milliseconds. NUM must be between 1 and 1000, inclusive. When
Tor is out of bandwidth, on a connection or globally, it will wait up to this
long before it tries to use that connection again. Note that 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. Can not be changed while tor is running. (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).
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. If multiple entries of this option are present in your
configuration file, Tor will perform stream isolation between listeners by
default. 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. (Default: 0)
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. 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")
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 or Single Onion Services. In these cases, this option is
ignored. (Default: 1)
UseGuardFraction 0|1|auto
This 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)
GuardLifetime N
days|weeks|months
If UseEntryGuards is set, minimum time to keep a guard on
our guard list before picking a new one. If less than one day, we use defaults
from the consensus directory. (Default: 0)
NumDirectoryGuards NUM
If UseEntryGuards is set to 1, 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 guard-n-primary-dir-guards-to-use consensus
parameter, and default to 3 if the consensus parameter isn’t set.
(Default: 0)
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 guard-n-primary-guards-to-use consensus
parameter, and default to 1 if the consensus parameter isn’t set.
(Default: 0)
NumPrimaryGuards NUM
If UseEntryGuards is set to 1, we will try to pick NUM
routers for our primary guard list, which is the set of routers we strongly
prefer when connecting to the Tor network. If NUM is 0, we try to learn the
number from the guard-n-primary-guards consensus parameter, and default to 3
if the consensus parameter isn’t set. (Default: 0)
VanguardsLiteEnabled 0|1|auto
This option specifies whether clients should use the
vanguards-lite subsystem to protect against guard discovery attacks. If
it’s set to auto, clients will do what the
vanguards-lite-enabled consensus parameter tells them to do, and will default
to enable the subsystem if the consensus parameter isn’t set. (Default:
auto)
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. For legacy reasons,
auto is accepted, but it has the same effect as 1. (Default: auto)
VirtualAddrNetworkIPv4 IPv4Address/bits
VirtualAddrNetworkIPv6 [IPv6Address]/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 larger network (that is,
one with a 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.
CIRCUIT TIMEOUT OPTIONS¶
The following options are useful for configuring timeouts related
to building Tor circuits and using them:
CircuitsAvailableTimeout NUM
Tor will attempt to keep at least one open, unused
circuit available for this amount of time. This option governs how long idle
circuits are kept open, as well as the amount of time Tor will keep a circuit
open to each of the recently used ports. This way when the Tor client is
entirely idle, it can expire all of its circuits, and then expire its TLS
connections. Note that the actual timeout value is uniformly randomized from
the specified value to twice that amount. (Default: 30 minutes; Max: 24
hours)
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)
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)
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)
DORMANT MODE OPTIONS¶
Tor can enter dormant mode to conserve power and network
bandwidth. The following options control when Tor enters and leaves dormant
mode:
DormantCanceledByStartup 0|1
By default, Tor starts in active mode if it was active
the last time it was shut down, and in dormant mode if it was dormant. But if
this option is true, Tor treats every startup event as user activity, and Tor
will never start in Dormant mode, even if it has been unused for a long time
on previous runs. (Default: 0)
Note: Packagers and application developers should change the value
of this option only with great caution: it has the potential to create
spurious traffic on the network. This option should only be used if Tor is
started by an affirmative user activity (like clicking on an application or
running a command), and not if Tor is launched for some other reason (for
example, by a startup process, or by an application that launches itself on
every login.)
DormantClientTimeout N
minutes|hours|days|weeks
If Tor spends this much time without any client activity,
enter a dormant state where automatic circuits are not built, and directory
information is not fetched. Does not affect servers or onion services. Must be
at least 10 minutes. (Default: 24 hours)
DormantOnFirstStartup 0|1
If true, then the first time Tor starts up with a fresh
DataDirectory, it starts in dormant mode, and takes no actions until the user
has made a request. (This mode is recommended if installing a Tor client for a
user who might not actually use it.) If false, Tor bootstraps the first time
it is started, whether it sees a user request or not.
After the first time Tor starts, it begins in dormant mode if it
was dormant before, and not otherwise. (Default: 0)
DormantTimeoutDisabledByIdleStreams 0|1
If true, then any open client stream (even one not
reading or writing) counts as client activity for the purpose of
DormantClientTimeout. If false, then only network activity counts. (Default:
1)
DormantTimeoutEnabled 0|1
If false, then no amount of time without activity is
sufficient to make Tor go dormant. Setting this option to zero is only
recommended for special-purpose applications that need to use the Tor binary
for something other than sending or receiving Tor traffic. (Default: 1)
NODE SELECTION OPTIONS¶
The following options restrict the nodes that a tor client (or
onion service) can use while building a circuit. These options can weaken
your anonymity by making your client behavior different from other Tor
clients:
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.
This option can appear multiple times: the values from multiple
lines are spliced together.
The ExcludeNodes option overrides this option: any node listed in
both EntryNodes and ExcludeNodes is treated as excluded. See ExcludeNodes
for more information on how to specify nodes.
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)
This option can appear multiple times: the values from multiple
lines are spliced together.
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 ExcludeNodes for more information on how to specify nodes. See
also the caveats on the ExitNodes option below.
This option can appear multiple times: the values from multiple
lines are spliced together.
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 ExcludeNodes for more
information on how to specify nodes.
This option can appear multiple times: the values from multiple
lines are spliced together.
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 MapAddress, overrides
this option.
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)
HSLayer2Nodes node,node,...
A list of identity fingerprints, nicknames, country
codes, and address patterns of nodes that are allowed to be used as the second
hop in all client or service-side Onion Service circuits. This option
mitigates attacks where the adversary runs middle nodes and induces your
client or service to create many circuits, in order to discover your primary
guard node. (Default: Any node in the network may be used in the second hop.)
(Example: HSLayer2Nodes ABCD1234CDEF5678ABCD1234CDEF5678ABCD1234,
{cc}, 255.254.0.0/8)
This option can appear multiple times: the values from multiple
lines are spliced together.
When this is set, the resulting hidden service paths will look
like:
C - G - L2 - M - Rend
C - G - L2 - M - HSDir
C - G - L2 - M - Intro
S - G - L2 - M - Rend
S - G - L2 - M - HSDir
S - G - L2 - M - Intro
where C is this client, S is the service, G is the Guard node, L2
is a node from this option, and M is a random middle node. Rend, HSDir, and
Intro point selection is not affected by this option.
This option may be combined with HSLayer3Nodes to create paths of
the form:
C - G - L2 - L3 - Rend
C - G - L2 - L3 - M - HSDir
C - G - L2 - L3 - M - Intro
S - G - L2 - L3 - M - Rend
S - G - L2 - L3 - HSDir
S - G - L2 - L3 - Intro
ExcludeNodes have higher priority than HSLayer2Nodes, which means
that nodes specified in ExcludeNodes will not be picked.
When either this option or HSLayer3Nodes are set, the /16 subnet
and node family restrictions are removed for hidden service circuits.
Additionally, we allow the guard node to be present as the Rend, HSDir, and
IP node, and as the hop before it. This is done to prevent the adversary
from inferring information about our guard, layer2, and layer3 node choices
at later points in the path.
This option is meant to be managed by a Tor controller such as
https://github.com/mikeperry-tor/vanguards that selects and updates this set
of nodes for you. Hence it does not do load balancing if fewer than 20 nodes
are selected, and if no nodes in HSLayer2Nodes are currently available for
use, Tor will not work. Please use extreme care if you are setting this
option manually.
HSLayer3Nodes node,node,...
A list of identity fingerprints, nicknames, country
codes, and address patterns of nodes that are allowed to be used as the third
hop in all client and service-side Onion Service circuits. This option
mitigates attacks where the adversary runs middle nodes and induces your
client or service to create many circuits, in order to discover your primary
or Layer2 guard nodes. (Default: Any node in the network may be used in the
third hop.)
(Example: HSLayer3Nodes ABCD1234CDEF5678ABCD1234CDEF5678ABCD1234,
{cc}, 255.254.0.0/8)
This option can appear multiple times: the values from multiple
lines are spliced together.
When this is set by itself, the resulting hidden service paths
will look like:
C - G - M - L3 - Rend
C - G - M - L3 - M - HSDir
C - G - M - L3 - M - Intro
S - G - M - L3 - M - Rend
S - G - M - L3 - HSDir
S - G - M - L3 - Intro
where C is this client, S is the service, G is the Guard node, L2
is a node from this option, and M is a random middle node. Rend, HSDir, and
Intro point selection is not affected by this option.
While it is possible to use this option by itself, it should be
combined with HSLayer2Nodes to create paths of the form:
C - G - L2 - L3 - Rend
C - G - L2 - L3 - M - HSDir
C - G - L2 - L3 - M - Intro
S - G - L2 - L3 - M - Rend
S - G - L2 - L3 - HSDir
S - G - L2 - L3 - Intro
ExcludeNodes have higher priority than HSLayer3Nodes, which means
that nodes specified in ExcludeNodes will not be picked.
When either this option or HSLayer2Nodes are set, the /16 subnet
and node family restrictions are removed for hidden service circuits.
Additionally, we allow the guard node to be present as the Rend, HSDir, and
IP node, and as the hop before it. This is done to prevent the adversary
from inferring information about our guard, layer2, and layer3 node choices
at later points in the path.
This option is meant to be managed by a Tor controller such as
https://github.com/mikeperry-tor/vanguards that selects and updates this set
of nodes for you. Hence it does not do load balancing if fewer than 20 nodes
are selected, and if no nodes in HSLayer3Nodes are currently available for
use, Tor will not work. Please use extreme care if you are setting this
option manually.
MiddleNodes node,node,...
A list of identity fingerprints and country codes of
nodes to use for "middle" hops in your normal circuits. Normal
circuits include all circuits except for direct connections to directory
servers. Middle hops are all hops other than exit and entry.
This option can appear multiple times: the values from multiple
lines are spliced together.
This is an experimental feature that is meant to be used by
researchers and developers to test new features in the Tor network safely.
Using it without care will strongly influence your anonymity. Other tor
features may not work with MiddleNodes. This feature might get removed in
the future.
The HSLayer2Node and HSLayer3Node options override this option for onion
service circuits, if they are set. The vanguards addon will read this
option, and if set, it will set HSLayer2Nodes and HSLayer3Nodes to nodes
from this set.
The ExcludeNodes option overrides this option: any node listed in both
MiddleNodes and ExcludeNodes is treated as excluded. See
the <<ExcludeNodes,ExcludeNodes>> for more information on how to specify nodes.
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 ExcludeNodes for more information on how
to specify nodes.
StrictNodes 0|1
If StrictNodes is set to 1, Tor will treat solely the
ExcludeNodes option as a requirement to follow for all the circuits you
generate, even if doing so will break functionality for you (StrictNodes does
not apply to ExcludeExitNodes, ExitNodes, MiddleNodes, or MapAddress). 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)
SERVER OPTIONS¶
The following options are useful only for servers (that is, if
ORPort is non-zero):
AccountingMax N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
Limits the max number of bytes sent and received within a
set time period using a given calculation rule (see AccountingStart and
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 TByte, a server could
send 900 GBytes and receive 800 GBytes and continue running. It will only
hibernate once one of the two reaches 1 TByte. 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".
Note that (as also described in the Bandwidth section) Tor uses
powers of two, not powers of ten: 1 GByte is 1024*1024*1024, not one
billion. Be careful: some internet service providers might count GBytes
differently.
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 relay
will go at full speed, use all the quota you specify, then hibernate for the
rest of the period. (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")
Address address
The address of this server, or a fully qualified domain
name of this server that resolves to an address. You can leave this unset, and
Tor will try to guess your address. If a domain name is provided, Tor will
attempt to resolve it and use the underlying IPv4/IPv6 address as its publish
address (taking precedence over the ORPort configuration). The publish address
is the one used to tell clients and other servers where to find your Tor
server; it doesn’t affect the address that your server binds to. To
bind to a different address, use the ORPort and OutboundBindAddress
options.
AddressDisableIPv6 0|1
By default, Tor will attempt to find the IPv6 of the
relay if there is no IPv4Only ORPort. If set, this option disables IPv6 auto
discovery. This disables IPv6 address resolution, IPv6 ORPorts, and IPv6
reachability checks. Also, the relay won’t publish an IPv6 ORPort in
its descriptor. (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. (Default: 0)
AssumeReachableIPv6 0|1|auto
Like AssumeReachable, but affects only the
relay’s own IPv6 ORPort. If this value is set to "auto", then
Tor will look at AssumeReachable instead. (Default: auto)
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.
Note: make sure that no MyFamily lines are present in your torrc
when relay is configured in bridge mode.
BridgeDistribution string
If set along with BridgeRelay, Tor will include a new
line in its bridge descriptor which indicates to the BridgeDB service how it
would like its bridge address to be given out. Set it to "none" if
you want BridgeDB to avoid distributing your bridge address, or
"any" to let BridgeDB decide. See
https://bridges.torproject.org/info for a more up-to-date list of options.
(Default: any)
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.
ContactInfo must be set to a working address if you run
more than one relay or bridge. (Really, everybody running a relay or bridge
should set it.)
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)
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
::/0), 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.
If you want to use a reduced exit policy rather than the default
exit policy, set "ReducedExitPolicy 1". If you want to
replace the default exit policy with your custom exit policy, end
your exit policy with either a reject : or an accept :.
Otherwise, you’re augmenting (prepending to) the default or
reduced 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.
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)
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)
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, the ReducedExitPolicy
option, or the default ExitPolicy (if no other exit policy option is
specified).
If ExitRelay is set to 0, no traffic is allowed to exit, and the
ExitPolicy, ReducedExitPolicy, and IPv6Exit options are ignored.
If ExitRelay is set to "auto", then Tor checks the
ExitPolicy, ReducedExitPolicy, and IPv6Exit options. If at least one of
these options is set, Tor behaves as if ExitRelay were set to 1. If none of
these exit policy options are set, Tor behaves as if ExitRelay were set to
0. (Default: auto)
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)
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.
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)
IPv6Exit 0|1
If set, and we are an exit node, allow clients to use us
for IPv6 traffic. When this option is set and ExitRelay is auto, we act as if
ExitRelay is 1. (Default: 0)
KeyDirectory DIR
Store secret keys in DIR. Can not be changed while tor is
running. (Default: the "keys" subdirectory of DataDirectory.)
KeyDirectoryGroupReadable 0|1|auto
If this option is set to 0, don’t allow the
filesystem group to read the KeyDirectory. If the option is set to 1, make the
KeyDirectory readable by the default GID. If the option is "auto",
then we use the setting for DataDirectoryGroupReadable when the KeyDirectory
is the same as the DataDirectory, and 0 otherwise. (Default: auto)
MainloopStats 0|1
Log main loop statistics every HeartbeatPeriod
seconds. This is a log level notice message designed to help developers
instrumenting Tor’s main event loop. (Default: 0)
MaxMemInQueues N
bytes|KBytes|MBytes|GBytes
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)
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 fingerprint,fingerprint,...
Declare that this Tor relay is controlled or administered
by a group or organization identical or similar to that of the other relays,
defined by their (possibly $-prefixed) identity fingerprints. This option can
be repeated many times, for convenience in defining large families: all
fingerprints in all MyFamily lines are merged into one list. When two relays
both declare that they are in the same 'family', Tor clients will not use them
in the same circuit. (Each relay only needs to list the other servers in its
family; it doesn’t need to list itself, but it won’t hurt if it
does.) Do not list any bridge relay as it would compromise its concealment.
If you run more than one relay, the MyFamily option on each relay
must list all other relays, as described above.
Note: do not use MyFamily when configuring your Tor instance as a
bridge.
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]. If not set, Unnamed will be used. Relays can
always be uniquely identified by their identity fingerprints.
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)
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)
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.
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 relay or bridge, publish descriptors to the appropriate
authorities". Other possibilities are "v3", meaning
"publish as if you’re a relay", and "bridge",
meaning "publish as if you’re a bridge".
ReducedExitPolicy 0|1
If set, use a reduced exit policy rather than the default
one.
The reduced exit policy is an alternative to the default exit
policy. It allows as many Internet services as possible while still blocking
the majority of TCP ports. Currently, the policy allows approximately 65
ports. This reduces the odds that your node will be used for peer-to-peer
applications.
The reduced exit policy is:
accept *:20-21
accept *:22
accept *:23
accept *:43
accept *:53
accept *:79
accept *:80-81
accept *:88
accept *:110
accept *:143
accept *:194
accept *:220
accept *:389
accept *:443
accept *:464
accept *:465
accept *:531
accept *:543-544
accept *:554
accept *:563
accept *:587
accept *:636
accept *:706
accept *:749
accept *:873
accept *:902-904
accept *:981
accept *:989-990
accept *:991
accept *:992
accept *:993
accept *:994
accept *:995
accept *:1194
accept *:1220
accept *:1293
accept *:1500
accept *:1533
accept *:1677
accept *:1723
accept *:1755
accept *:1863
accept *:2082
accept *:2083
accept *:2086-2087
accept *:2095-2096
accept *:2102-2104
accept *:3128
accept *:3389
accept *:3690
accept *:4321
accept *:4643
accept *:5050
accept *:5190
accept *:5222-5223
accept *:5228
accept *:5900
accept *:6660-6669
accept *:6679
accept *:6697
accept *:8000
accept *:8008
accept *:8074
accept *:8080
accept *:8082
accept *:8087-8088
accept *:8232-8233
accept *:8332-8333
accept *:8443
accept *:8888
accept *:9418
accept *:9999
accept *:10000
accept *:11371
accept *:19294
accept *:19638
accept *:50002
accept *:64738
reject *:*
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)
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)
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)
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)
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)
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 or a localhost DNS
service in case no nameservers are found in a given configuration.)
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)
ServerDNSTestAddresses
hostname,hostname,...
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")
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. (IPv4 addresses should written
as-is; IPv6 addresses should be wrapped in square brackets.) (Default:
none)
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) (Default: none)
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. (Default: none)
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)
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)
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)
STATISTICS OPTIONS¶
Relays publish most statistics in a document called the extra-info
document. The following options affect the different types of statistics
that Tor relays collect and publish:
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. If ExtraInfoStatistics is
enabled, it will be published as part of the extra-info document. (Default:
1)
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 the 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 the 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 the
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 the 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 the extra-info
document. (Default: 0)
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. Disabling this option also removes bandwidth usage
statistics, and GeoIPFile and GeoIPv6File hashes from the extra-info file.
Bridge ServerTransportPlugin lines are always included in the extra-info file,
because they are required by BridgeDB. (Default: 1)
HiddenServiceStatistics 0|1
Relays and bridges 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 enabled, it will be published as part of the extra-info
document. (Default: 1)
OverloadStatistics 0|1*
Relays and bridges only. When this option is enabled, a
Tor relay will write an overload general line in the server descriptor if the
relay is considered overloaded. (Default: 1)
A relay is considered overloaded if at least one of these
conditions is met:
•A certain ratio of ntor onionskins are
dropped.
•The OOM was invoked.
•TCP Port exhaustion.
+
If ExtraInfoStatistics is enabled, it can also put two more specific
overload lines in the extra-info document if at least one of these
conditions is met:
- Connection rate limits have been reached (read and write side).
- File descriptors are exhausted.
PaddingStatistics 0|1
Relays and bridges only. When this option is enabled, Tor
collects statistics for padding cells sent and received by this relay, in
addition to total cell counts. These statistics are rounded, and omitted if
traffic is low. This information is important for load balancing decisions
related to padding. If ExtraInfoStatistics is enabled, it will be published as
a part of the extra-info document. (Default: 1)
DIRECTORY SERVER OPTIONS¶
The following options are useful only for directory servers.
(Relays with enough bandwidth automatically become directory servers; see
DirCache for details.)
DirCache 0|1
When this option is set, Tor caches all current directory
documents except extra info documents, and accepts client requests for them.
If DownloadExtraInfo is set, cached extra info documents are also
cached. Setting DirPort is not required for DirCache, because
clients connect via the ORPort by default. Setting either DirPort or
BridgeRelay and setting DirCache to 0 is not supported. (Default: 1)
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.
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. This
port can only be IPv4.
As of Tor 0.4.6.1-alpha, non-authoritative relays (see
AuthoritativeDirectory) will not publish the DirPort but will still listen
on it. Clients don’t use the DirPorts on relays, so it is safe for
you to remove the DirPort from your torrc configuration.
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.
MaxConsensusAgeForDiffs N
minutes|hours|days|weeks
When this option is nonzero, Tor caches will not try to
generate consensus diffs for any consensus older than this amount of time. If
this option is set to zero, Tor will pick a reasonable default from the
current networkstatus document. You should not set this option unless your
cache is severely low on disk space or CPU. If you need to set it, keeping it
above 3 or 4 hours will help clients much more than setting it to zero.
(Default: 0)
DENIAL OF SERVICE MITIGATION OPTIONS¶
Tor has a series of built-in denial of service mitigation options
that can be individually enabled/disabled and fine-tuned, but by default Tor
directory authorities will define reasonable values for the network and no
explicit configuration is required to make use of these protections.
The following is a series of configuration options for relays and
then options for onion services and how they work.
The mitigations take place at relays, and are as follows:
1.If a single client address makes too many concurrent
connections (this is configurable via DoSConnectionMaxConcurrentCount), hang
up on further connections.
2.If a single client IP address (v4 or v6) makes
circuits too quickly (default values are more than 3 per second, with an
allowed burst of 90, see DoSCircuitCreationRate and DoSCircuitCreationBurst)
while also having too many connections open (default is 3, see
DoSCircuitCreationMinConnections), tor will refuse any new circuit (CREATE
cells) for the next while (random value between 1 and 2 hours).
3.If a client asks to establish a rendezvous point to
you directly (ex: Tor2Web client), ignore the request.
These defenses can be manually controlled by torrc options, but
relays will also take guidance from consensus parameters using these same
names, so there’s no need to configure anything manually. In doubt,
do not change those values.
The values set by the consensus, if any, can be found here:
https://consensus-health.torproject.org/#consensusparams
If any of the DoS mitigations are enabled, a heartbeat message
will appear in your log at NOTICE level which looks like:
DoS mitigation since startup: 429042 circuits rejected, 17 marked addresses.
2238 connections closed. 8052 single hop clients refused.
The following options are useful only for a public relay. They
control the Denial of Service mitigation subsystem described above.
DoSCircuitCreationEnabled 0|1|auto
Enable circuit creation DoS mitigation. If set to 1
(enabled), tor will cache client IPs along with statistics in order to detect
circuit DoS attacks. If an address is positively identified, tor will activate
defenses against the address. See DoSCircuitCreationDefenseType option for
more details. This is a client to relay detection only. "auto" means
use the consensus parameter. If not defined in the consensus, the value is 0.
(Default: auto)
DoSCircuitCreationBurst NUM
The allowed circuit creation burst per client IP address.
If the circuit rate and the burst are reached, a client is marked as executing
a circuit creation DoS. "0" means use the consensus parameter. If
not defined in the consensus, the value is 90. (Default: 0)
DoSCircuitCreationDefenseTimePeriod N
seconds|minutes|hours
The base time period in seconds that the DoS defense is
activated for. The actual value is selected randomly for each activation from
N+1 to 3/2 * N. "0" means use the consensus parameter. If not
defined in the consensus, the value is 3600 seconds (1 hour). (Default:
0)
DoSCircuitCreationDefenseType NUM
This is the type of defense applied to a detected client
address. The possible values are:
1: No defense.
2: Refuse circuit creation for the
DoSCircuitCreationDefenseTimePeriod period of time.
"0" means use the consensus parameter. If not defined in
the consensus, the value is 2. (Default: 0)
DoSCircuitCreationMinConnections NUM
Minimum threshold of concurrent connections before a
client address can be flagged as executing a circuit creation DoS. In other
words, once a client address reaches the circuit rate and has a minimum of NUM
concurrent connections, a detection is positive. "0" means use the
consensus parameter. If not defined in the consensus, the value is 3.
(Default: 0)
DoSCircuitCreationRate NUM
The allowed circuit creation rate per second applied per
client IP address. If this option is 0, it obeys a consensus parameter. If not
defined in the consensus, the value is 3. (Default: 0)
DoSConnectionEnabled 0|1|auto
Enable the connection DoS mitigation. If set to 1
(enabled), for client address only, this allows tor to mitigate against large
number of concurrent connections made by a single IP address. "auto"
means use the consensus parameter. If not defined in the consensus, the value
is 0. (Default: auto)
DoSConnectionDefenseType NUM
This is the type of defense applied to a detected client
address for the connection mitigation. The possible values are:
1: No defense.
2: Immediately close new connections.
"0" means use the consensus parameter. If not defined in
the consensus, the value is 2. (Default: 0)
DoSConnectionMaxConcurrentCount NUM
The maximum threshold of concurrent connection from a
client IP address. Above this limit, a defense selected by
DoSConnectionDefenseType is applied. "0" means use the consensus
parameter. If not defined in the consensus, the value is 100. (Default:
0)
DoSConnectionConnectRate NUM
The allowed rate of client connection from a single
address per second. Coupled with the burst (see below), if the limit is
reached, the address is marked and a defense is applied
(DoSConnectionDefenseType) for a period of time defined by
DoSConnectionConnectDefenseTimePeriod. If not defined or set to 0, it is
controlled by a consensus parameter. (Default: 0)
DoSConnectionConnectBurst NUM
The allowed burst of client connection from a single
address per second. See the DoSConnectionConnectRate for more details on this
detection. If not defined or set to 0, it is controlled by a consensus
parameter. (Default: 0)
DoSConnectionConnectDefenseTimePeriod N
seconds|minutes|hours
The base time period in seconds that the client
connection defense is activated for. The actual value is selected randomly for
each activation from N+1 to 3/2 * N. If not defined or set to 0, it is
controlled by a consensus parameter. (Default: 24 hours)
DoSRefuseSingleHopClientRendezvous
0|1|auto
Refuse establishment of rendezvous points for single hop
clients. In other words, if a client directly connects to the relay and sends
an ESTABLISH_RENDEZVOUS cell, it is silently dropped. "auto" means
use the consensus parameter. If not defined in the consensus, the value is 0.
(Default: auto)
For onion services, mitigations are a work in progress and
multiple options are currently available.
The introduction point defense is a rate limit on the number of
introduction requests that will be forwarded to a service by each of its
honest introduction point routers. This can prevent some types of
overwhelming floods from reaching the service, but it will also prevent
legitimate clients from establishing new connections.
The following options are per onion service:
HiddenServiceEnableIntroDoSDefense 0|1
Enable DoS defense at the intropoint level. When this is
enabled, the rate and burst parameter (see below) will be sent to the intro
point which will then use them to apply rate limiting for introduction request
to this service.
The introduction point honors the consensus parameters except if
this is specifically set by the service operator using this option. The
service never looks at the consensus parameters in order to enable or
disable this defense. (Default: 0)
HiddenServiceEnableIntroDoSBurstPerSec NUM
The allowed client introduction burst per second at the
introduction point. If this option is 0, it is considered infinite and thus if
HiddenServiceEnableIntroDoSDefense is set, it then effectively disables
the defenses. (Default: 200)
HiddenServiceEnableIntroDoSRatePerSec NUM
The allowed client introduction rate per second at the
introduction point. If this option is 0, it is considered infinite and thus if
HiddenServiceEnableIntroDoSDefense is set, it then effectively disables
the defenses. (Default: 25)
The rate is the maximum number of clients a service will ask its
introduction points to allow every seconds. And the burst is a parameter
that allows that many within one second.
For example, the default values of 25 and 200 respectively means
that for every introduction points a service has (default 3 but can be
configured with HiddenServiceNumIntroductionPoints), 25 clients per
seconds will be allowed to reach the service and 200 at most within 1 second
as a burst. This means that if 200 clients are seen within 1 second, it will
take 8 seconds (200/25) for another client to be able to be allowed to
introduce due to the rate of 25 per second.
This might be too much for your use case or not, fine tuning these
values is hard and are likely different for each service operator.
Why is this not helping reachability of the service? Because the
defenses are at the introduction point, an attacker can easily flood all
introduction point rendering the service unavailable due to no client being
able to pass through. But, the service itself is not overwhelmed with
connetions allowing it to function properly for the few clients that were
able to go through or other any services running on the same tor
instance.
The bottom line is that this protects the network by preventing an
onion service to flood the network with new rendezvous circuits that is
reducing load on the network.
A secondary mitigation is available, based on prioritized dispatch
of rendezvous circuits for new connections. The queue is ordered based on
effort a client chooses to spend at computing a proof-of-work function.
The following options are per onion service:
HiddenServicePoWDefensesEnabled 0|1
Enable proof-of-work based service DoS mitigation. If set
to 1 (enabled), tor will include parameters for an optional client puzzle in
the encrypted portion of this hidden service’s descriptor. Incoming
rendezvous requests will be prioritized based on the amount of effort a client
chooses to make when computing a solution to the puzzle. The service will
periodically update a suggested amount of effort, based on attack load, and
disable the puzzle entirely when the service is not overloaded. (Default:
0)
HiddenServicePoWQueueRate NUM
The sustained rate of rendezvous requests to dispatch per
second from the priority queue. Has no effect when proof-of-work is disabled.
If this is set to 0 there’s no explicit limit and we will process
requests as quickly as possible. (Default: 250)
HiddenServicePoWQueueBurst NUM
The maximum burst size for rendezvous requests handled
from the priority queue at once. (Default: 2500)
These options are applicable to both onion services and their
clients:
CompiledProofOfWorkHash 0|1|auto
When proof-of-work DoS mitigation is active, both the
services themselves and the clients which connect will use a dynamically
generated hash function as part of the puzzle computation.
If this option is set to 1, puzzles will only be solved and
verified using the compiled implementation (about 20x faster) and we choose
to fail rather than using a slower fallback. If it’s 0, the compiler
will never be used. By default, the compiler is always tried if possible but
the interpreter is available as a fallback. (Default: auto)
See also --list-modules, these proof of work options have no
effect unless the "pow" module is enabled at compile time.
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.
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)
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).
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.)
AuthDirMiddleOnly AddressPattern...
Authoritative directories only. A set of address patterns
for servers that will be listed as middle-only in any network status document
this authority publishes, if AuthDirListMiddleOnly is set.
AuthDirFastGuarantee N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
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|TBytes|KBits|MBits|GBits|TBits
Authoritative directories only. If non-zero, this
advertised capacity or more is always sufficient to satisfy the bandwidth
requirement for the Guard flag. (Default: 2 MBytes)
AuthDirHasIPv6Connectivity 0|1
Authoritative directories only. When set to 0, OR ports
with an IPv6 address are not included in the authority’s votes. When
set to 1, IPv6 OR ports are tested for reachability like IPv4 OR ports. If the
reachability test succeeds, the authority votes for the IPv6 ORPort, and votes
Running for the relay. If the reachability test fails, the authority does not
vote for the IPv6 ORPort, and does not vote Running (Default: 0)
The content of the consensus depends on the number of voting authorities
that set AuthDirHasIPv6Connectivity:
If no authorities set AuthDirHasIPv6Connectivity 1, there will be no
IPv6 ORPorts in the consensus.
If a minority of authorities set AuthDirHasIPv6Connectivity 1,
unreachable IPv6 ORPorts will be removed from the consensus. But the
majority of IPv4-only authorities will still vote the relay as Running.
Reachable IPv6 ORPort lines will be included in the consensus
If a majority of voting authorities set AuthDirHasIPv6Connectivity 1,
relays with unreachable IPv6 ORPorts will not be listed as Running.
Reachable IPv6 ORPort lines will be included in the consensus
(To ensure that any valid majority will vote relays with unreachable
IPv6 ORPorts not Running, 75% of authorities must set
AuthDirHasIPv6Connectivity 1.)
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.
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.)
AuthDirListMiddleOnly 0|1
Authoritative directories only. If set to 1, this
directory has some opinion about which nodes should only be used in the middle
position. (Do not set this to 1 unless you plan to list questionable relays as
"middle only"; otherwise, you are effectively voting against
middle-only status for every relay.)
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)
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: 1)
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.
AuthDirRejectRequestsUnderLoad 0|1
If set, the directory authority will start rejecting
directory requests from non relay connections by sending a 503 error code if
it is under bandwidth pressure (reaching the configured limit if any). Relays
will always tried to be answered even if this is on. (Default: 1)
AuthDirBadExitCCs CC,...
AuthDirInvalidCCs CC,...
AuthDirMiddleOnlyCCs 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.
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)
AuthDirTestEd25519LinkKeys 0|1
Authoritative directories only. If this option is set to
0, then we treat relays as "Running" if their RSA key is correct
when we probe them, regardless of their Ed25519 key. We should only ever set
this option to 0 if there is some major bug in Ed25519 link authentication
that causes us to label all the relays as not Running. (Default: 1)
AuthDirTestReachability 0|1
Authoritative directories only. If set to 1, then we
periodically check every relay we know about to see whether it is running. If
set to 0, we vote Running for every relay, and don’t perform these
tests. (Default: 1)
AuthDirVoteGuard node,node,...
A list of identity fingerprints or country codes or
address patterns of nodes to vote Guard for regardless of their uptime and
bandwidth. See ExcludeNodes for more information on how to specify
nodes.
AuthDirVoteGuardBwThresholdFraction FRACTION
The Guard flag bandwidth performance threshold fraction
that is the fraction representing who gets the Guard flag out of all measured
bandwidth. (Default: 0.75)
AuthDirVoteGuardGuaranteeTimeKnown N
seconds|minutes|hours|days|weeks
A relay with at least this much weighted time known can
be considered familiar enough to be a guard. (Default: 8 days)
AuthDirVoteGuardGuaranteeWFU FRACTION
A level of weighted fractional uptime (WFU) is that is
sufficient to be a Guard. (Default: 0.98)
AuthDirVoteStableGuaranteeMinUptime N
seconds|minutes|hours|days|weeks
If a relay’s uptime is at least this value, then
it is always considered stable, regardless of the rest of the network.
(Default: 30 days)
AuthDirVoteStableGuaranteeMTBF N
seconds|minutes|hours|days|weeks
If a relay’s mean time between failures (MTBF) is
least this value, then it will always be considered stable. (Default: 5
days)
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)
ConsensusParams STRING
STRING is a space-separated list of key=value pairs that
Tor will include in the "params" line of its networkstatus vote.
This directive can be specified multiple times so you don’t have to put
it all on one line.
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)
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)
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)
MinUptimeHidServDirectoryV2 N
seconds|minutes|hours|days|weeks
Minimum uptime of a relay to be accepted as a hidden
service directory by directory authorities. (Default: 96 hours)
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.
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.
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.
V3AuthDistDelay N
seconds|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)
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)
V3AuthVoteDelay N
seconds|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)
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)
V3BandwidthsFile FILENAME
V3 authoritative directories only. Configures the
location of the bandwidth-authority generated file storing information on
relays' measured bandwidth capacities. To avoid inconsistent reads, bandwidth
data should be written to temporary file, then renamed to the configured
filename. (Default: unset)
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.
HIDDEN SERVICE OPTIONS¶
The following options are used to configure a hidden service. Some
options apply per service and some apply for the whole tor instance.
The next section describes the per service options that can only
be set after the HiddenServiceDir directive
PER SERVICE OPTIONS:
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)
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. If DIRECTORY does not exist, Tor
will create it. Please note that you cannot add new Onion Service to already
running Tor instance if Sandbox is enabled. (Note: in current versions
of Tor, if DIRECTORY is a relative path, it will be relative to the 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.)
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.
HiddenServiceExportCircuitID protocol
The onion service will use the given protocol to expose
the global circuit identifier of each inbound client circuit. The only
protocol supported right now 'haproxy'. This option is only for v3 services.
(Default: none)
The haproxy option works in the following way: when the feature is
enabled, the Tor process will write a header line when a client is
connecting to the onion service. The header will look like this:
"PROXY TCP6 fc00:dead:beef:4dad::ffff:ffff ::1 65535
42\r\n"
We encode the "global circuit identifier" as the last
32-bits of the first IPv6 address. All other values in the header can safely
be ignored. You can compute the global circuit identifier using the
following formula given the IPv6 address
"fc00:dead:beef:4dad::AABB:CCDD":
global_circuit_id = (0xAA << 24) + (0xBB << 16) +
(0xCC << 8) + 0xDD;
In the case above, where the last 32-bits are 0xffffffff, the
global circuit identifier would be 4294967295. You can use this value
together with Tor’s control port to terminate particular circuits
using their global circuit identifiers. For more information about this see
control-spec.txt.
The HAProxy version 1 protocol is described in detail at
https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt
HiddenServiceOnionBalanceInstance 0|1
If set to 1, this onion service becomes an OnionBalance
instance and will accept client connections destined to an OnionBalance
frontend. In this case, Tor expects to find a file named "ob_config"
inside the
HiddenServiceDir directory with content:
MasterOnionAddress <frontend_onion_address>
where <frontend_onion_address> is the onion address of the
OnionBalance frontend (e.g.
wrxdvcaqpuzakbfww5sxs6r2uybczwijzfn2ezy2osaj7iox7kl7nhad.onion).
HiddenServiceMaxStreams N
The maximum number of simultaneous streams (connections)
per rendezvous circuit. The maximum value allowed is 65535. (Setting this to 0
will allow an unlimited number of simultaneous 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)
HiddenServiceNumIntroductionPoints NUM
Number of introduction points the hidden service will
have. You can’t have more than 20. (Default: 3)
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. Note that
address-port pairs have to be comma-separated.
HiddenServiceVersion 3
A list of rendezvous service descriptor versions to
publish for the hidden service. Currently, only version 3 is supported.
(Default: 3)
PER INSTANCE OPTIONS:
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. Can not be changed while tor is running.
(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". Can not be changed while tor is
running. (Default: 0)
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)
CLIENT AUTHORIZATION¶
Service side:
To configure client authorization on the service side, the
"<HiddenServiceDir>/authorized_clients/" directory needs to exist. Each file
in that directory should be suffixed with ".auth" (i.e. "alice.auth"; the
file name is irrelevant) and its content format MUST be:
<auth-type>:<key-type>:<base32-encoded-public-key>
The supported <auth-type> are: "descriptor". The supported <key-type> are:
"x25519". The <base32-encoded-public-key> is the base32 representation of
the raw key bytes only (32 bytes for x25519).
Each file MUST contain one line only. Any malformed file will be
ignored. Client authorization will only be enabled for the service if tor
successfully loads at least one authorization file.
Note that once you've configured client authorization, anyone else with the
address won't be able to access it from this point on. If no authorization is
configured, the service will be accessible to anyone with the onion address.
Revoking a client can be done by removing their ".auth" file, however the
revocation will be in effect only after the tor process gets restarted or if
a SIGHUP takes place.
Client side:
To access a v3 onion service with client authorization as a client, make sure
you have ClientOnionAuthDir set in your torrc. Then, in the
<ClientOnionAuthDir> directory, create an .auth_private file for the onion
service corresponding to this key (i.e. 'bob_onion.auth_private'). The
contents of the <ClientOnionAuthDir>/<user>.auth_private file should look like:
<56-char-onion-addr-without-.onion-part>:descriptor:x25519:<x25519 private key in base32>
For more information, please see
https://2019.www.torproject.org/docs/tor-onion-service.html.en#ClientAuthorization
.
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)
DirAllowPrivateAddresses 1
EnforceDistinctSubnets 0
AuthDirMaxServersPerAddr 0
ClientBootstrapConsensusAuthorityDownloadInitialDelay 0
ClientBootstrapConsensusFallbackDownloadInitialDelay 0
ClientBootstrapConsensusAuthorityOnlyDownloadInitialDelay 0
ClientDNSRejectInternalAddresses 0
ClientRejectInternalAddresses 0
CountPrivateBandwidth 1
ExitPolicyRejectPrivate 0
ExtendAllowPrivateAddresses 1
V3AuthVotingInterval 5 minutes
V3AuthVoteDelay 20 seconds
V3AuthDistDelay 20 seconds
TestingV3AuthInitialVotingInterval 150 seconds
TestingV3AuthInitialVoteDelay 20 seconds
TestingV3AuthInitialDistDelay 20 seconds
TestingAuthDirTimeToLearnReachability 0 minutes
MinUptimeHidServDirectoryV2 0 minutes
TestingServerDownloadInitialDelay 0
TestingClientDownloadInitialDelay 0
TestingServerConsensusDownloadInitialDelay 0
TestingClientConsensusDownloadInitialDelay 0
TestingBridgeDownloadInitialDelay 10
TestingBridgeBootstrapDownloadInitialDelay 0
TestingClientMaxIntervalWithoutRequest 5 seconds
TestingDirConnectionMaxStall 30 seconds
TestingEnableConnBwEvent 1
TestingEnableCellStatsEvent 1
TestingAuthDirTimeToLearnReachability N
seconds|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)
TestingAuthKeyLifetime N
seconds|minutes|hours|days|weeks|months
Overrides the default lifetime for a signing Ed25519 TLS
Link authentication key. (Default: 2 days)
TestingAuthKeySlop N
seconds|minutes|hours
TestingBridgeBootstrapDownloadInitialDelay N
Initial delay in seconds for how long clients should wait
before downloading a bridge descriptor for a new bridge. Changing this
requires that TestingTorNetwork is set. (Default: 0)
TestingBridgeDownloadInitialDelay N
How long to wait (in seconds) once clients have
successfully downloaded a bridge descriptor, before trying another download
for that same bridge. Changing this requires that TestingTorNetwork is
set. (Default: 10800)
TestingClientConsensusDownloadInitialDelay N
Initial delay in seconds for when clients should download
consensuses. Changing this requires that TestingTorNetwork is set.
(Default: 0)
TestingClientDownloadInitialDelay N
Initial delay in seconds for when clients should download
things in general. Changing this requires that TestingTorNetwork is
set. (Default: 0)
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)
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 ExcludeNodes for more information on how to
specify nodes.
In order for this option to have any effect,
TestingTorNetwork has to be set. See ExcludeNodes 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 ExcludeNodes 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 ExcludeNodes 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.
TestingDirConnectionMaxStall N
seconds|minutes
Let a directory connection stall this long before
expiring it. Changing this requires that TestingTorNetwork is set.
(Default: 5 minutes)
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)
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)
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)
TestingLinkKeySlop N
seconds|minutes|hours
TestingMinExitFlagThreshold N
KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
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 KBytes. (Default: 0)
TestingMinFastFlagThreshold N
bytes|KBytes|MBytes|GBytes|TBytes|KBits|MBits|GBits|TBits
Minimum value for the Fast flag. Overrides the ordinary
minimum taken from the consensus when TestingTorNetwork is set. (Default:
0.)
TestingMinTimeToReportBandwidth N
seconds|minutes|hours
Do not report our measurements for our maximum observed
bandwidth for any time period that has lasted for less than this amount of
time. Values over 1 day have no effect. (Default: 1 day)
TestingServerConsensusDownloadInitialDelay N
Initial delay in seconds for when servers should download
consensuses. Changing this requires that TestingTorNetwork is set.
(Default: 0)
TestingServerDownloadInitialDelay N
Initial delay in seconds for when servers should download
things in general. Changing this requires that TestingTorNetwork is
set. (Default: 0)
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.)
TestingV3AuthInitialDistDelay N
seconds|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)
TestingV3AuthInitialVoteDelay N
seconds|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)
TestingV3AuthInitialVotingInterval N
seconds|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)
TestingV3AuthVotingStartOffset N
seconds|minutes|hours
Directory authorities offset voting start time by this
much. Changing this requires that TestingTorNetwork is set. (Default:
0)
NON-PERSISTENT OPTIONS¶
These options are not saved to the torrc file by the
"SAVECONF" controller command. Other options of this type are
documented in control-spec.txt, section 5.4. End-users should mostly ignore
them.
__ControlPort, __DirPort, __DNSPort,
__ExtORPort, __NATDPort, __ORPort, __SocksPort,
__TransPort
These underscore-prefixed options are variants of the
regular Port options. They behave the same, except they are not saved to the
torrc file by the controller’s SAVECONF command.
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
Default location of the configuration file.
$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.
CacheDirectory/cached-certs
Contains downloaded directory key certificates that are
used to verify authenticity of documents generated by the Tor directory
authorities.
CacheDirectory/cached-consensus and/or
cached-microdesc-consensus
The most recent consensus network status document
we’ve downloaded.
CacheDirectory/cached-descriptors and
cached-descriptors.new
These files contain the 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.
CacheDirectory/cached-extrainfo and
cached-extrainfo.new
Similar to cached-descriptors, but holds
optionally-downloaded "extra-info" documents. Relays use these
documents to send inessential information about statistics, bandwidth history,
and network health to the authorities. They aren’t fetched by default.
See DownloadExtraInfo for more information.
CacheDirectory/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/state
Contains a set of persistent key-value mappings. These
include:
•the current entry guards and their status.
•the current bandwidth accounting values.
•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/sr-state
Authority only. This file is used to record
information about the current status of the shared-random-value voting
state.
CacheDirectory/diff-cache
Directory cache only. Holds older consensuses and
diffs from oldest to the most recent consensus of each type compressed in
various ways. Each file contains a set of key-value arguments describing its
contents, followed by a single NUL byte, followed by the main file
contents.
DataDirectory/bw_accounting
This file is obsolete and the data is now stored in the
state file instead. Used to track bandwidth accounting values (when the
current period starts and ends; how much has been read and written so far this
period).
DataDirectory/control_auth_cookie
This file can be used only when cookie authentication is
enabled. Used for cookie authentication with the controller. Location can be
overridden by the CookieAuthFile configuration option. Regenerated on startup.
See control-spec.txt in torspec for details.
DataDirectory/lock
This file is used to prevent two Tor instances from using
the same data directory. If access to this file is locked, data directory is
already in use by Tor.
DataDirectory/key-pinning-journal
Used by authorities. A line-based file that records
mappings between RSA1024 and Ed25519 identity keys. Authorities enforce these
mappings, so that once a relay has picked an Ed25519 key, stealing or
factoring the RSA1024 key will no longer let an attacker impersonate the
relay.
KeyDirectory/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 put it in this
file.
KeyDirectory/authority_certificate
Only directory authorities use this file. A v3 directory
authority’s certificate which authenticates the authority’s
current vote- and consensus-signing key using its master identity key.
KeyDirectory/authority_signing_key
Only directory authorities use this file. A v3 directory
authority’s signing key that is used to sign votes and consensuses.
Corresponds to the authority_certificate cert.
KeyDirectory/legacy_certificate
As authority_certificate; used only when
V3AuthUseLegacyKey is set. See documentation for V3AuthUseLegacyKey.
KeyDirectory/legacy_signing_key
As authority_signing_key: used only when
V3AuthUseLegacyKey is set. See documentation for V3AuthUseLegacyKey.
KeyDirectory/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.
KeyDirectory/ed25519_master_id_public_key
The public part of a relay’s Ed25519 permanent
identity key.
KeyDirectory/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 encrypted. If so, Tor will not be able to
generate new signing keys automatically; you’ll need to use tor
--keygen to do so.
KeyDirectory/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, which in turn authenticates other keys (and router
descriptors).
KeyDirectory/ed25519_signing_cert
The certificate which authenticates
"ed25519_signing_secret_key" as having been signed by the Ed25519
master key.
KeyDirectory/secret_onion_key and
secret_onion_key.old
A relay’s RSA1024 short-term onion key. Used to
decrypt old-style ("TAP") circuit extension requests. The
.old file holds the previously generated key, which the relay uses to
handle any requests that were made by clients that didn’t have the new
one.
KeyDirectory/secret_onion_key_ntor and
secret_onion_key_ntor.old
A relay’s Curve25519 short-term onion key. Used to
handle modern ("ntor") circuit extension requests. The .old
file holds the previously generated key, which the relay uses to handle any
requests that were made by clients that didn’t have the new one.
DataDirectory/fingerprint
Only used by servers. Contains the fingerprint of the
server’s RSA identity key.
DataDirectory/fingerprint-ed25519
Only used by servers. Contains the fingerprint of the
server’s ed25519 identity key.
DataDirectory/hashed-fingerprint
Only used by bridges. Contains the hashed fingerprint of
the bridge’s identity key. (That is, the hash of the hash of the
identity key.)
DataDirectory/approved-routers
Only used by authoritative directory servers. Each line
lists a status and an identity, separated by whitespace. Identities can be
hex-encoded RSA fingerprints, or base-64 encoded ed25519 public keys. See the
fingerprint file in a tor relay’s DataDirectory for an
example fingerprint line. If the status is !reject, then descriptors
from the given identity are rejected by this server. If it is !invalid
then descriptors are accepted, but marked in the vote as not valid. If it is
!badexit, then the authority will vote for it to receive a BadExit
flag, indicating that it shouldn’t be used for traffic leaving the Tor
network. If it is !middleonly, then the authority will vote for it to
only be used in the middle of circuits. (Neither rejected nor invalid relays
are included in the consensus.)
DataDirectory/v3-status-votes
Only for v3 authoritative directory servers. This file
contains status votes from all the authoritative directory servers.
CacheDirectory/unverified-consensus
Contains a network consensus document that has been
downloaded, but which we didn’t have the right certificates to check
yet.
CacheDirectory/unverified-microdesc-consensus
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
fair 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/stats/hidserv-stats
Only used by servers. This file is used to collect
approximate counts of what fraction of the traffic is hidden service
rendezvous traffic, and approximately how many hidden services the relay has
seen.
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.
Note
The clients will ignore any extra subdomains prepended to a hidden service
hostname. Supposing you have "xyz.onion" as your hostname, you can
ask your clients to connect to "www.xyz.onion" or
"irc.xyz.onion" for virtual-hosting purposes.
HiddenServiceDirectory/private_key
Contains the private key for this hidden service.
HiddenServiceDirectory/client_keys
Contains 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.