@ -23,14 +23,19 @@ outgoing connections, but more is possible.
-proxy=ip:port Set the proxy server. If SOCKS5 is selected (default), this proxy
server will be used to try to reach .onion addresses as well.
You need to use -noonion or -onion=0 to explicitly disable
outbound access to onion services.
-onion=ip:port Set the proxy server to use for Tor onion services. You do not
need to set this if it's the same as -proxy. You can use -no onion
need to set this if it's the same as -proxy. You can use -onion=0
to explicitly disable access to onion services.
Note: Only the -proxy option sets the proxy for DNS requests;
with -onion they will not route over Tor, so use -proxy if you
have privacy concerns.
-listen When using -proxy, listening is disabled by default. If you want
to run an onion service (see next section), you'll need to enable
it explicitly.
to manually configure an onion service (see section 3), you'll
need to enable it explicitly.
-connect=X When behind a Tor proxy, you can specify .onion addresses instead
-addnode=X of IP addresses or hostnames in these parameters. It requires
@ -40,19 +45,112 @@ outgoing connections, but more is possible.
-onlynet=onion Make outgoing connections only to .onion addresses. Incoming
connections are not affected by this option. This option can be
specified multiple times to allow multiple network types, e.g.
ipv4, ipv6, or onion.
ipv4, ipv6 or onion. If you use this option with values other
than onion you *cannot* disable onion connections; outgoing onion
connections will be enabled when you use -proxy or -onion. Use
-noonion or -onion=0 if you want to be sure there are no outbound
onion connections over the default proxy or your defined -proxy.
In a typical situation, this suffices to run behind a Tor proxy:
./bitcoind -proxy=127.0.0.1:9050
## 2. Automatically create a Bitcoin Core onion service
## 2. Manually create a Bitcoin Core onion service
Bitcoin Core makes use of Tor's control socket API to create and destroy
ephemeral onion services programmatically. This means that if Tor is running and
proper authentication has been configured, Bitcoin Core automatically creates an
onion service to listen on. The goal is to increase the number of available
onion nodes.
If you configure your Tor system accordingly, it is possible to make your node also
reachable from the Tor network. Add these lines to your /etc/tor/torrc (or equivalent
config file): *Needed for Tor version 0.2.7.0 and older versions of Tor only. For newer
versions of Tor see [Section 3 ](#3-automatically-listen-on-tor ).*
This feature is enabled by default if Bitcoin Core is listening (`-listen`) and
it requires a Tor connection to work. It can be explicitly disabled with
`-listenonion=0` . If it is not disabled, it can be configured using the
`-torcontrol` and `-torpassword` settings.
To see verbose Tor information in the bitcoind debug log, pass `-debug=tor` .
### Control Port
You may need to set up the Tor Control Port. On Linux distributions there may be
some or all of the following settings in `/etc/tor/torrc` , generally commented
out by default (if not, add them):
```
ControlPort 9051
CookieAuthentication 1
CookieAuthFileGroupReadable 1
```
Add or uncomment those, save, and restart Tor (usually `systemctl restart tor`
or `sudo systemctl restart tor` on most systemd-based systems, including recent
Debian and Ubuntu, or just restart the computer).
On some systems (such as Arch Linux), you may also need to add the following
line:
```
DataDirectoryGroupReadable 1
```
### Authentication
Connecting to Tor's control socket API requires one of two authentication
methods to be configured: cookie authentication or bitcoind's `-torpassword`
configuration option.
#### Cookie authentication
For cookie authentication, the user running bitcoind must have read access to
the `CookieAuthFile` specified in the Tor configuration. In some cases this is
preconfigured and the creation of an onion service is automatic. Don't forget to
use the `-debug=tor` bitcoind configuration option to enable Tor debug logging.
If a permissions problem is seen in the debug log, e.g. `tor: Authentication
cookie /run/tor/control.authcookie could not be opened (check permissions)`, it
can be resolved by adding both the user running Tor and the user running
bitcoind to the same Tor group and setting permissions appropriately.
On Debian-derived systems, the Tor group will likely be `debian-tor` and one way
to verify could be to list the groups and grep for a "tor" group name:
```
getent group | cut -d: -f1 | grep -i tor
```
You can also check the group of the cookie file. On most Linux systems, the Tor
auth cookie will usually be `/run/tor/control.authcookie` :
```
stat -c '%G' /run/tor/control.authcookie
```
Once you have determined the `${TORGROUP}` and selected the `${USER}` that will
run bitcoind, run this as root:
```
usermod -a -G ${TORGROUP} ${USER}
```
Then restart the computer (or log out) and log in as the `${USER}` that will run
bitcoind.
#### `torpassword` authentication
For the `-torpassword=password` option, the password is the clear text form that
was used when generating the hashed password for the `HashedControlPassword`
option in the Tor configuration file.
The hashed password can be obtained with the command `tor --hash-password
password` (refer to the [Tor Dev
Manual](https://2019.www.torproject.org/docs/tor-manual.html.en) for more
details).
## 3. Manually create a Bitcoin Core onion service
You can also manually configure your node to be reachable from the Tor network.
Add these lines to your `/etc/tor/torrc` (or equivalent config file):
HiddenServiceDir /var/lib/tor/bitcoin-service/
HiddenServicePort 8333 127.0.0.1:8334
@ -106,44 +204,10 @@ for normal IPv4/IPv6 communication, use:
./bitcoind -onion=127.0.0.1:9050 -externalip=7zvj7a2imdgkdbg4f2dryd5rgtrn7upivr5eeij4cicjh65pooxeshid.onion -discover
## 3. Automatically create a Bitcoin Core onion service
Starting with Tor version 0.2.7.1 it is possible, through Tor's control socket
API, to create and destroy 'ephemeral' onion services programmatically.
Bitcoin Core has been updated to make use of this.
This means that if Tor is running (and proper authentication has been configured),
Bitcoin Core automatically creates an onion service to listen on. This will positively
affect the number of available .onion nodes.
This new feature is enabled by default if Bitcoin Core is listening (`-listen`), and
requires a Tor connection to work. It can be explicitly disabled with `-listenonion=0`
and, if not disabled, configured using the `-torcontrol` and `-torpassword` settings.
To show verbose debugging information, pass `-debug=tor` .
Connecting to Tor's control socket API requires one of two authentication methods to be
configured. It also requires the control socket to be enabled, e.g. put `ControlPort 9051`
in `torrc` config file. For cookie authentication the user running bitcoind must have read
access to the `CookieAuthFile` specified in Tor configuration. In some cases this is
preconfigured and the creation of an onion service is automatic. If permission problems
are seen with `-debug=tor` they can be resolved by adding both the user running Tor and
the user running bitcoind to the same group and setting permissions appropriately. On
Debian-based systems the user running bitcoind can be added to the debian-tor group,
which has the appropriate permissions. Before starting bitcoind you will need to re-login
to allow debian-tor group to be applied. Otherwise you will see the following notice: "tor:
Authentication cookie /run/tor/control.authcookie could not be opened (check permissions)"
on debug.log.
An alternative authentication method is the use
of the `-torpassword=password` option. The `password` is the clear text form that
was used when generating the hashed password for the `HashedControlPassword` option
in the tor configuration file. The hashed password can be obtained with the command
`tor --hash-password password` (read the tor manual for more details).
## 4. Privacy recommendations
- Do not add anything but Bitcoin Core ports to the onion service created in section 2 .
- Do not add anything but Bitcoin Core ports to the onion service created in section 3.
If you run a web service too, create a new onion service for that.
Otherwise it is trivial to link them, which may reduce privacy. Onion
services created automatically (as in section 3 ) always have only one port
services created automatically (as in section 2) always have only one port
open.
MarcoFalke
4 years ago