[Tor] Towards Whonix & Tails

[kiminuo]

Contributes to #12848

This PR adds --UseOnlyRunningTor command line option and its purpose is to use only a pre-running Tor instance to which we can connect. The purpose is then:

• WW2 should be compatible with Whonix or Tails¹ then because it is not possible to spin up a new Tor instance in these distributions because Tor-over-Tor problem would occur.
• To facilitate this, --UseOnlyRunningTor does not rely on Tor control port².

How to test

On master branch, start WW, disable "terminate Tor on exit" in settings, start WW again and turn it off -> you should have a Tor process running on port 37150

On the PR's branch, connect to TorSocksPort=37150 and set a made up port for TorControlPort to make sure it CANNOT be used.

dotnet build && dotnet run --framework net8.0 -- --TorSocksPort=37150 --TorControlPort=63999 --UseOnlyRunningTor=true

You should be able to do a coinjoin or just use your wallet normally without a hiccup.

Footnotes

1. That was a goal for a long time. ↩

2. It seems it works but the cost is that we do not use TorMonitor. ↩

[yahiheb]

Tested, LGTM.

If UseTor is false and UseOnlyRunningTor is used and set to true, should the wallet use an already running Tor?

[kiminuo]

If UseTor is false and UseOnlyRunningTor is used and set to true, should the wallet use an already running Tor?

This is a good point. I believe I can make sure that UseOnlyRunningTor=true leads to UseTor=true (whatever its value was).

Thinking about it a bit more, I think we could modify code to support:

UseTor=True|False|OnlyRunning

WDYT?

[yahiheb]

Thinking about it a bit more, I think we could modify code to support:

UseTor=True|False|OnlyRunning

WDYT?

It seems good to me.

In such case if UseTor=OnlyRunning and no Tor is already running we fall back to UseTor=True?

[kiminuo]

@yahiheb FYI, this was wrong it was if (TorControlAvailable) so we could report exceptions when we shouldn't. That's probably what you reported over Slack.

[kiminuo]

Thinking about it a bit more, I think we could modify code to support:
UseTor=True|False|OnlyRunning
WDYT?

It seems good to me.

In such case if UseTor=OnlyRunning and no Tor is already running we fall back to UseTor=True?

I created an alternative PR #12991 for this where you can use:

• UseTor=False (backward compatibility)
• UseTor=True (backward compatibility)
• UseTor=Disabled
• UseTor=Enabled
• UseTor=EnabledOnlyRunning (used to be OnlyRunning)

The names are not that great as I would like to preserve backward compatibility ...

[kiminuo]

Replaced with #12991