* 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
* chore: implement create_db for substrate (fix broken branch)
* Correct rebase artifacts
* chore: remove todo statement
* chore: rename BlockDb to NextBlock
* chore: return empty tuple instead of empty array for event storage
* Finish rebasing
* .Minor tweaks to remove leftover variables
These may be rebase artifacts.
---------
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
The coordinator already had one of these, albeit implemented much worse than
the one now properly introduced. It had to either be sending or receiving,
whereas the new one can do both at the same time.
This replaces said instance and enables pleasant patterns when implementing the
processor/coordinator.
* Add a function to deterministically decide which Serai blocks should be co-signed
Has a 5 minute latency between co-signs, also used as the maximal latency
before a co-sign is started.
* Get all active tributaries we're in at a specific block
* Add and route CosignSubstrateBlock, a new provided TX
* Split queued cosigns per network
* Rename BatchSignId to SubstrateSignId
* Add SubstrateSignableId, a meta-type for either Batch or Block, and modularize around it
* Handle the CosignSubstrateBlock provided TX
* Revert substrate_signer.rs to develop (and patch to still work)
Due to SubstrateSigner moving when the prior multisig closes, yet cosigning
occurring with the most recent key, a single SubstrateSigner can be reused.
We could manage multiple SubstrateSigners, yet considering the much lower
specifications for cosigning, I'd rather treat it distinctly.
* Route cosigning through the processor
* Add note to rename SubstrateSigner post-PR
I don't want to do so now in order to preserve the diff's clarity.
* Implement cosign evaluation into the coordinator
* Get tests to compile
* Bug fixes, mark blocks without cosigners available as cosigned
* Correct the ID Batch preprocesses are saved under, add log statements
* Create a dedicated function to handle cosigns
* Correct the flow around Batch verification/queueing
Verifying `Batch`s could stall when a `Batch` was signed before its
predecessors/before the block it's contained in was cosigned (the latter being
inevitable as we can't sign a block containing a signed batch before signing
the batch).
Now, Batch verification happens on a distinct async task in order to not block
the handling of processor messages. This task is the sole caller of verify in
order to ensure last_verified_batch isn't unexpectedly mutated.
When the processor message handler needs to access it, or needs to queue a
Batch, it associates the DB TXN with a lock preventing the other task from
doing so.
This lock, as currently implemented, is a poor and inefficient design. It
should be modified to the pattern used for cosign management. Additionally, a
new primitive of a DB-backed channel may be immensely valuable.
Fixes a standing potential deadlock and a deadlock introduced with the
cosigning protocol.
* Working full-stack tests
After the last commit, this only required extending a timeout.
* Replace "co-sign" with "cosign" to make finding text easier
* Update the coordinator tests to support cosigning
* Inline prior_batch calculation to prevent panic on rotation
Noticed when doing a final review of the branch.
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.
Prior, we only supported a single Tributary per network, and spawned a task to
handled Processor messages per Tributary. Now, we handle Processor messages per
network, yet we still only supported a single Tributary in that handling
function.
Now, when we handle a message, we load the Tributary which is relevant. Once we
know it, we ensure we have it (preventing race conditions), and then proceed.
We do need work to check if we should have a Tributary, or if we're not
participating. We also need to check if a Tributary has been retired, meaning
we shouldn't handle any transactions related to them, and to clean up retired
Tributaries.
