exclude_badExits/README.md

This extends nusenu's basic idea of using the stem library to dynamically exclude nodes that are likely to be bad by putting them on the ExcludeNodes or ExcludeExitNodes setting of a running Tor.

• https://github.com/nusenu/noContactInfo_Exit_Excluder
• https://github.com/TheSmashy/TorExitRelayExclude

The basic cut is to exclude Exit nodes that do not have a contact. That can be extended to nodes that do not have an email in the contact etc.

But there's a problem, and your Tor notice.log will tell you about it: you could exclude the nodes needed to access hidden services or directorues. So we need to add to the process the concept of a whitelist. In addition, we may have our own blacklist of nodes we want to exclude, or use these lists for other applications like selektor.

So we make two files that are structured in YAML:

/etc/tor/yaml/torrc-goodnodes.yaml
GoodNodes:
  Relays:
    IntroductionPoints:
      - NODEFINGERPRINT
  ...
By default all sections of the goodnodes.yaml are used as a whitelist.

/etc/tor/yaml/torrc-badnodes.yaml
BadNodes:
  ExcludeExitNodes:
    BadExit:
      # $0000000000000000000000000000000000000007

That part requires PyYAML https://github.com/yaml/pyyaml/

Right now only the ExcludeExitNodes section is used by we may add ExcludeNodes later, and by default all sub-sections of the badnodes.yaml are used as a ExcludeExitNodes but it can be customized with the lWanted commandline arg.

The original idea has also been extended to add different conditions for exclusion: the --contact commandline arg is a comma sep list of conditions:

• Empty - no contact info
• NoEmail - no @ sign in the contact', More may be added later.

Because you don't want to exclude the introduction points to any onion you want to connect to, --white_onions should whitelist the introduction points to a comma sep list of onions, but is currently broken in stem 1.8.0: see:

• https://github.com/torproject/stem/issues/96
• https://gitlab.torproject.org/legacy/trac/-/issues/25417

--torrc_output will write the torrc ExcludeNodes configuration to a file.

Now for the final part: we lookup the Contact info of every server that is currently in our Tor, and check it for its existence. If it fails to provide the well-know url, we assume its a bogus relay and add it to a list of nodes that goes on ExcludeNodes - not just exclude Exit.

If the Contact info is good we add the list of fingerprints to add to ExitNodes, a whitelist of relays to use as exits.

--proof_output will write the contact info as a ciiss dictionary to a YAML file. If the proof is uri-rsa, the well-known file of fingerprints is downloaded and the fingerprints are added on a 'fps' field we create of that fingerprint's entry of the YAML dictionary. This file is read at the beginning of the program to start with a trust database, and only new contact info from new relays are added to the dictionary.

You can expect it to take an hour or two the first time this is run:

700 domains.

For usage, do ```python3 exclude_badExits.py --help`