At some point we need to properly revive the functional tests:
   https://github.com/asn-d6/onionbalance/issues/46

Tor has a custom PKCS#1 padding format (does not include the
algorithmIdentifier as specified in RFC3447), so we had to monkey-patch the
padding function of Cryptodome for this to work...

Because of the change to Cryptodome we also had to change the interface of
sign_digest() to actually take the message and not the digest directly. That's
because Cryptodome wants to hash the message itself.
Co-authored-by: Federico Ceratto <federico.ceratto@gmail.com>

Co-authored-by: Federico Ceratto <federico.ceratto@gmail.com>

We are basically replicating the logic of:
   tpo/core/tor#40237
into OBv3.

to solve #19

Each with their own aesthetics and thresholds.

That's to catch issue #20.