Add signature v2 format

[adriansmares]

Summary

References #976

This PR introduces a new signature format for requests, in order to avoid situations in which validator requests are fulfilled by nodes which are not targeted by the RPC.

This PR is based on #976 in order to avoid merge conflicts - only the last two commits are relevant here.

Changes

• Remove the static header check. Receptors will still keep adding it, but it is ignored from now on.
• Add v2 signature format, which also takes into account the target axon hotkey. The v2 signature ensures that the signature cannot be faked by an intermediary that is not a validator.
• Ensure that nonces cannot be replayed by disallowing equality. Allowing nonce equality renders the nonce moot.
• On chain parameters of an axon are now always updated. Previously they would be updated only on IP/port changes.

[camfairchild]

why not just up the network version itself?

edit: then use the version to decide on the parse method

[adriansmares]

why not just up the network version itself?

edit: then use the version to decide on the parse method

That wouldn't be backward compatible - new dendrites cannot talk to old axons (since old axons expect the old format). In this way there can be a transition period in which new dendrites can speak with old axons, and old axons allow traffic from old dendrites. In some future version, the v1 signature format can be completely removed and only v2 would remain.

[camfairchild]

why not just up the network version itself?

edit: then use the version to decide on the parse method

That wouldn't be backward compatible - new dendrites cannot talk to old axons (since old axons expect the old format). In this way there can be a transition period in which new dendrites can speak with old axons, and old axons allow traffic from old dendrites. In some future version, the v1 signature format can be completely removed and only v2 would remain.

I'm not suggesting you get rid of this. I'm suggesting you use the wire protocol version to do this instead of adding metadata

[adriansmares]

I'm not suggesting you get rid of this. I'm suggesting you use the wire protocol version to do this instead of adding metadata

So I've ended up doing this based on the advertised version on chain. The dendrite/receptor decides based on the endpoint version which signature to use.

Note that this is a bit awkward right now - we cannot use version 3.4.2 as a version cutoff point, since 3.4.2 axons cannot parse this signature, but also nobunaga is still on version 3.4.2, so in order to test this, one must manually bump his __version_as_int__. Unit tests do try 3.4.3 as a receiving version however.

[unconst]

LGTM

[unconst]

I think we can safely begin the review process on this PR. @eduardogr I would like your take as well.

[Eugene-hu]

Nice job! I like the new signature function. There are a few things that we need to fix before merging

[Eugene-hu]

LGTM, Nice job!

[eduardogr]

LGTM,
(commented already, i miss a couple of unit tests but everything good)

Thanks for this!

[Eugene-hu]

@adriansmares Merging this PR today, it will be released in the next version