* Move logic for evaluating if a cosign should occur to its own file
Cleans it up and makes it more robust.
* Have expected_next_batch return an error instead of retrying
While convenient to offer an error-free implementation, it potentially caused
very long lived lock acquisitions in handle_processor_message.
* Unify and clean DkgConfirmer and DkgRemoval
Does so via adding a new file for the common code, SigningProtocol.
Modifies from_cache to return the preprocess with the machine, as there's no
reason not to. Also removes an unused Result around the type.
Clarifies the security around deterministic nonces, removing them for
saved-to-disk cached preprocesses. The cached preprocesses are encrypted as the
DB is not a proper secret store.
Moves arguments always present in the protocol from function arguments into the
struct itself.
Removes the horribly ugly code in DkgRemoval, fixing multiple issues present
with it which would cause it to fail on use.
* Set SeraiBlockNumber in cosign.rs as it's used by the cosigning protocol
* Remove unnecessary Clone from lambdas in coordinator
* Remove the EventDb from Tributary scanner
We used per-Transaction DB TXNs so on error, we don't have to rescan the entire
block yet only the rest of it. We prevented scanning multiple transactions by
tracking which we already had.
This is over-engineered and not worth it.
* Implement borsh for HasEvents, removing the manual encoding
* Merge DkgConfirmer and DkgRemoval into signing_protocol.rs
Fixes a bug in DkgConfirmer which would cause it to improperly handle indexes
if any validator had multiple key shares.
* Strictly type DataSpecification's Label
* Correct threshold_i_map_to_keys_and_musig_i_map
It didn't include the participant's own index and accordingly was offset.
* Create TributaryBlockHandler
This struct contains all variables prior passed to handle_block and stops them
from being passed around again and again.
This also ensures fatal_slash is only called while handling a block, as needed
as it expects to operate under perfect consensus.
* Inline accumulate, store confirmation nonces with shares
Inlining accumulate makes sense due to the amount of data accumulate needed to
be passed.
Storing confirmation nonces with shares ensures that both are available or
neither. Prior, one could be yet the other may not have been (requiring an
assert in runtime to ensure we didn't bungle it somehow).
* Create helper functions for handling DkgRemoval/SubstrateSign/Sign Tributary TXs
* Move Label into SignData
All of our transactions which use SignData end up with the same common usage
pattern for Label, justifying this.
Removes 3 transactions, explicitly de-duplicating their handlers.
* Remove CurrentlyCompletingKeyPair for the non-contextual DkgKeyPair
* Remove the manual read/write for TributarySpec for borsh
This struct doesn't have any optimizations booned by the manual impl. Using
borsh reduces our scope.
* Use temporary variables to further minimize LoC in tributary handler
* Remove usage of tuples for non-trivial Tributary transactions
* Remove serde from dkg
serde could be used to deserialize intenrally inconsistent objects which could
lead to panics or faults.
The BorshDeserialize derives have been replaced with a manual implementation
which won't produce inconsistent objects.
* Abstract Future generics using new trait definitions in coordinator
* Move published_signed_transaction to tributary/mod.rs to reduce the size of main.rs
* Split coordinator/src/tributary/mod.rs into spec.rs and transaction.rs
* coordinator/src/db.rs db macro implimentation
* fixed fmt errors
* converted txn functions to get/set counterparts
* use take_signed_transaction function
* fix for two fo the tests
* Misc tweaks
* Minor tweaks
---------
Co-authored-by: Luke Parker <lukeparker5132@gmail.com>
* Remove NetworkId from processor-messages
Because intent binds to the sender/receiver, it's not needed for intent.
The processor knows what the network is.
The coordinator knows which to use because it's sending this message to the
processor for that network.
Also removes the unused zeroize.
* ProcessorMessage::Completed use Session instead of key
* Move SubstrateSignId to Session
* Finish replacing key with session
* Update the coordinator to give key shares based on weight, not based on existence
Participants are now identified by their starting index. While this compiles,
the following is unimplemented:
1) A conversion for DKG `i` values. It assumes the threshold `i` values used
will be identical for the MuSig signature used to confirm the DKG.
2) Expansion from compressed values to full values before forwarding to the
processor.
* Add a fn to the DkgConfirmer to convert `i` values as needed
Also removes TODOs regarding Serai ensuring validator key uniqueness +
validity. The current infra achieves both.
* Have the Tributary DB track participation by shares, not by count
* Prevent a node from obtaining 34% of the maximum amount of key shares
This is actually mainly intended to set a bound on message sizes in the
coordinator. Message sizes are amplified by the amount of key shares held, so
setting an upper bound on said amount lets it determine constants. While that
upper bound could be 150, that'd be unreasonable and increase the potential for
DoS attacks.
* Correct the mechanism to detect if sufficient accumulation has occured
It used to check if the latest accumulation hit the required threshold. Now,
accumulations may jump past the required threshold. The required mechanism is
to check the threshold wasn't prior met and is now met.
* Finish updating the coordinator to handle a multiple key share per validator environment
* Adjust stategy re: preventing noce reuse in DKG Confirmer
* Add TODOs regarding dropped transactions, add possible TODO fix
* Update tests/coordinator
This doesn't add new multi-key-share tests, it solely updates the existing
single key-share tests to compile and run, with the necessary fixes to the
coordinator.
* Update processor key_gen to handle generating multiple key shares at once
* Update SubstrateSigner
* Update signer, clippy
* Update processor tests
* Update processor docker tests
Replaces plan IDs with key + ID, letting the coordinator determine the sessions
for the plans.
Properly scopes which plan IDs are set on which tributaries, and ensures we
have the necessary tributaries at time of handling.
Adds Event::SetRetired to validator-sets.
Emit TributaryRetired.
Replaces is_active_set, which made multiple network requests, with
is_retired_tributary, a DB read.
Performs most of the removals necessary upon TributaryRetired.
Still needs to clean up the actual Tributary/Tendermint tasks.
* Revert "Correct the prior documented TOCTOU"
This reverts commit d50fe87801.
* Correct the prior documented TOCTOU
d50fe87801 edited the challenge for the Batch to
fix it. This won't produce Batch n+1 until Batch n is successfully published
and verified. It's an alternative strategy able to be reviewed, with a much
smaller impact to scope.
The new set publishing a `Batch` completes the handover protocol. The new set
should only publish a `Batch` once it believes the old set has completed all of
its on-external-chain activity, marking it honest and finite.
With the handover comes the acceptance of liability, hence the requirement for
all of the on-Serai-chain activity also needing verification. While most
activity would be verified in-real-time (upon ::Batch messages), the new set
will now explicitly verify the complete set of `Batch`s before beginning its
preprocess for its own `Batch` (the one accepting the handover).
Renames Update to SignedBatch.
Checks Batch equality via a hash of the InInstructions. That prevents needing
to keep the Batch in node state or TX introspect.
This is a possibility under the new deterministic nonce scheme.
While there is a concern of us never creating a transaction with a nonce,
blocking everything, we should always create transactions. We'll always publish
preprocesses, and while we'll only publish shares if everyone else does, we
only allocate for shares once everyone else does.
The initial TODO was simply to use one ExternalBlock per all batches in the
block. This would require publishing ExternalBlock after the last batch,
requiring knowing the last batch. While we could add such a pipeline, it'd
require:
1) Initial preprocesses using a distinct message from BatchPreprocess
2) An additional message sent after all BatchPreprocess are sent
Unfortunately, both would require tweaks to the SubstrateSigner which aren't
worth the complexity compared to the solution here, at least, not at this time.
While this will cause, if a Tributary is signing a block whose total batch data
exceeds 25 kB, to use multiple transactions which could be optimized out by
'better' local data pipelining, that's an extreme edge case. Given the temporal
nature of each Tributary, it's also an acceptable edge.
This does no longer achieve synchrony over external blocks accordingly. While
signed batches have synchrony, as they embed their block hash, batches being
signed don't have cryptographic synchrony on their contents. This means
validators who are eclipsed may produce invalid shares, as they sign a
different batch. This will be introduced in a follow-up commit.
add_active_tributary writes the spec to disk before it returns, so even if the
VecDeque it pushes to isn't popped, the tributary will still be loaded on boot.
