I think you're misunderstanding something here, with onion services traffic is e2e encrypted and self-authenticated, as Matt explains:
> When you connect to an onion service, how do you know no one is MitM'ing you? Easy. It's impossible. The bad guy would have to be in your browser (more accurately: between the browser part of Tor Browser and the Tor process it runs in the background) or between the Tor process the onion service operator is running and the webserver it's pointing at. If you assume your Tor Browser hasn't been compromised, and you assume the onion service is being run intelligently, then a MitM attack is impossible. (And if the onion service isn't being run intelligently, can you really trust its operator to do HTTPS intelligently?) > > https://matt.traudt.xyz/posts/dont-https-your-o44SnkW2.html