message: Improve tor documentation
diff: @@ -105,3 +105,68 @@ a connection to Tor can be made. It can be configured with the `-listenonion`,
  `-torcontrol` and `-torpassword` settings. To show verbose debugging
  information, pass `-debug=tor`.
  +In more practical way this what you need to do to actually setting tor to operate
  +in this new configuration. Firstly you need to be sure that the user under which
  +bitcoind is going to be executed has write permission on tor system directories
  +(e.g. /var/run/tor/control.authcookie). On Debian and Ubuntu system add such user
  +to the `debian-tor` group should be enough (i.e. `sudo adduser $USER debian-tor`)
  +
  +Then add these lines to `/etc/tor/torrc` (i.e `sudo nano /etc/tor/torrc`)
  +
  + ControlPort 9051
  + CookieAuthentication 1
  + HashedControlPassword <TheHashOfYourTorPassword>
  +
  +to get the hash of your Tor password just use this command
  +
  + tor --hash-password <YourTorPassword>
  +
  +Next you have to restart the Tor service:
  +
  + sudo service tor restart
  +
  +Add these lines to your `bitcoin.conf` file
  +
  + proxy=127.0.0.1:9050
  + listen=1
  + onlynet=onion
  + listenonion=1
  + discover=0
  + torcontrol=127.0.0.1:9051
  + torpassword=<TheHashOfYourTorPassword>
  +
  +Then issue this command to get the url of your onion hidden service
  +
  + bitcoin-cli getnetworkinfo | grep -w addr
  +
  +you should get an output like this one
  +
  + "address": "k3a23xgpg2jugxjr.onion"
  +
  +Pick the onion domain and verify on bitnodes.21.co if you it is
  +reachable.
  +
  +If you want to leverage the nature of tor and stop a DDoS attack to your
  +node, firstly stop your node:
  +
  + bitcoin-cli stop
  +
  +Remove your peer file and tor private key from bitcoin data directory
  +
  + cd ~/.bitcoin
  + rm onion_private_key
  + rm peers.dat
  +
  +Removing the `onion_private_key` serves the aim of having a new onion URL for
  +your bitcoin node, in such a way your attacker won't be able to harm you
  +again in the near term cause the prev URL is not valid any more.
  +
  +Removing `peer.dat` will let you fetch a bunch of new peers from the seeder
  +this somewhat reduce the risk of peering again with your attacker.
  +
  +If you want to maintain the same onion URL across reboot avoid to delete
  +the onion private key file.
  +
  +Restart your node:
  +
  + bitcoind -daemon
  