Scan ports for my onion bitcoin node and RPC calls

Question

I'm getting to work my first bitcoin node, it is running P2P through Tor network.

1: How can it be scanned? how can I see if its exposing any port, or port 8333?

2: How can I make RPC calls through Tor?.... maybe this is not the best way because of security for the RPC API and calls in plain data...

Thank you!

Prayank · Accepted Answer · 2021-02-23 16:27:25Z

1: How can it be scanned? how can I see if its exposing any port, or port 8333?

Use getnetworkinfo RPC and results should have one onion address and port number mentioned if onion service is created for Bitcoin Core:

localaddresses": [
  {
    "address": "omy7kj7zwvfg5luayideh73uqb2latkoyyy5h65y4atv3fymnlxlzwqd.onion",
    "port": 8333,
    "score": 4
  }
]

2: How can I make RPC calls through Tor?.... maybe this is not the best way because of security for the RPC API and calls in plain data.

ieatpizza · Accepted Answer · 2021-02-23 15:49:55Z

This seems to be more a question about Tor than a Bitcoin specific question, but:

If your bitcoind is set up to use a Tor socks proxy, by default, it will not listen for incoming connections (because by doing so, you'd be listening on your real IP address, which defeats the security you'd gain from Tor). However, if you really want to help the Bitcoin network by making your Tor-protected bitcoind available on port 8333, you will need to configure it as a hidden service. Refer here for information about this: https://en.bitcoin.it/wiki/Setting_up_a_Tor_hidden_service
You should set up a hidden service for your RPC port if you wish to make RPC calls through Tor, then from the computer sending RPC commands, send those commands through a local Tor SOCKS proxy. Set up your bitcoind to allow RPC calls only from 127.0.0.1 port 8332 (this will ensure your bitcoind will only accept RPC calls made through Tor), then set up a hidden service for port 8332.

2 Answers 2