mirror of
https://gitlab.torproject.org/tpo/core/tor.git
synced 2024-11-10 21:23:58 +01:00
59 lines
2.0 KiB
Plaintext
59 lines
2.0 KiB
Plaintext
|
|
Special Hostnames in Tor
|
|
Nick Mathewson
|
|
|
|
1. Overview
|
|
|
|
Most of the time, Tor treats user-specified hostnames as opaque: When
|
|
the user connects to www.torproject.org, Tor picks an exit node and uses
|
|
that node to connect to "www.torproject.org". Some hostnames, however,
|
|
can be used to override Tor's default behavior and circuit-building
|
|
rules.
|
|
|
|
These hostnames can be passed to Tor as the address part of a SOCKS4a or
|
|
SOCKS5 request. If the application is connected to Tor using an IP-only
|
|
method (such as SOCKS4, TransPort, or NatdPort), these hostnames can be
|
|
substituted for certain IP addresses using the MapAddress configuration
|
|
option or the MAPADDRESS control command.
|
|
|
|
2. .exit
|
|
|
|
SYNTAX: [hostname].[name-or-digest].exit
|
|
[name-or-digest].exit
|
|
|
|
Hostname is a valid hostname; [name-or-digest] is either the nickname of a
|
|
Tor node or the hex-encoded digest of that node's public key.
|
|
|
|
When Tor sees an address in this format, it uses the specified hostname as
|
|
the exit node. If no "hostname" component is given, Tor defaults to the
|
|
published IPv4 address of the exit node.
|
|
|
|
It is valid to try to resolve hostnames, and in fact upon success Tor
|
|
will cache an internal mapaddress of the form
|
|
"www.google.com.foo.exit=64.233.161.99.foo.exit" to speed subsequent
|
|
lookups.
|
|
|
|
The .exit notation is disabled by default as of Tor 0.2.2.1-alpha, due
|
|
to potential application-level attacks.
|
|
|
|
EXAMPLES:
|
|
www.example.com.exampletornode.exit
|
|
|
|
Connect to www.example.com from the node called "exampletornode".
|
|
|
|
exampletornode.exit
|
|
|
|
Connect to the published IP address of "exampletornode" using
|
|
"exampletornode" as the exit.
|
|
|
|
3. .onion
|
|
|
|
SYNTAX: [digest].onion
|
|
|
|
The digest is the first eighty bits of a SHA1 hash of the identity key for
|
|
a hidden service, encoded in base32.
|
|
|
|
When Tor sees an address in this format, it tries to look up and connect to
|
|
the specified hidden service. See rend-spec.txt for full details.
|
|
|