* Upstream GBP, divisor, circuit abstraction, and EC gadgets from FCMP++
* Initial eVRF implementation
Not quite done yet. It needs to communicate the resulting points and proofs to
extract them from the Pedersen Commitments in order to return those, and then
be tested.
* Add the openings of the PCs to the eVRF as necessary
* Add implementation of secq256k1
* Make DKG Encryption a bit more flexible
No longer requires the use of an EncryptionKeyMessage, and allows pre-defined
keys for encryption.
* Make NUM_BITS an argument for the field macro
* Have the eVRF take a Zeroizing private key
* Initial eVRF-based DKG
* Add embedwards25519 curve
* Inline the eVRF into the DKG library
Due to how we're handling share encryption, we'd either need two circuits or to
dedicate this circuit to the DKG. The latter makes sense at this time.
* Add documentation to the eVRF-based DKG
* Add paragraph claiming robustness
* Update to the new eVRF proof
* Finish routing the eVRF functionality
Still needs errors and serialization, along with a few other TODOs.
* Add initial eVRF DKG test
* Improve eVRF DKG
Updates how we calculcate verification shares, improves performance when
extracting multiple sets of keys, and adds more to the test for it.
* Start using a proper error for the eVRF DKG
* Resolve various TODOs
Supports recovering multiple key shares from the eVRF DKG.
Inlines two loops to save 2**16 iterations.
Adds support for creating a constant time representation of scalars < NUM_BITS.
* Ban zero ECDH keys, document non-zero requirements
* Implement eVRF traits, all the way up to the DKG, for secp256k1/ed25519
* Add Ristretto eVRF trait impls
* Support participating multiple times in the eVRF DKG
* Only participate once per key, not once per key share
* Rewrite processor key-gen around the eVRF DKG
Still a WIP.
* Finish routing the new key gen in the processor
Doesn't touch the tests, coordinator, nor Substrate yet.
`cargo +nightly fmt && cargo +nightly-2024-07-01 clippy --all-features -p serai-processor`
does pass.
* Deduplicate and better document in processor key_gen
* Update serai-processor tests to the new key gen
* Correct amount of yx coefficients, get processor key gen test to pass
* Add embedded elliptic curve keys to Substrate
* Update processor key gen tests to the eVRF DKG
* Have set_keys take signature_participants, not removed_participants
Now no one is removed from the DKG. Only `t` people publish the key however.
Uses a BitVec for an efficient encoding of the participants.
* Update the coordinator binary for the new DKG
This does not yet update any tests.
* Add sensible Debug to key_gen::[Processor, Coordinator]Message
* Have the DKG explicitly declare how to interpolate its shares
Removes the hack for MuSig where we multiply keys by the inverse of their
lagrange interpolation factor.
* Replace Interpolation::None with Interpolation::Constant
Allows the MuSig DKG to keep the secret share as the original private key,
enabling deriving FROST nonces consistently regardless of the MuSig context.
* Get coordinator tests to pass
* Update spec to the new DKG
* Get clippy to pass across the repo
* cargo machete
* Add an extra sleep to ensure expected ordering of `Participation`s
* Update orchestration
* Remove bad panic in coordinator
It expected ConfirmationShare to be n-of-n, not t-of-n.
* Improve documentation on functions
* Update TX size limit
We now no longer have to support the ridiculous case of having 49 DKG
participations within a 101-of-150 DKG. It does remain quite high due to
needing to _sign_ so many times. It'd may be optimal for parties with multiple
key shares to independently send their preprocesses/shares (despite the
overhead that'll cause with signatures and the transaction structure).
* Correct error in the Processor spec document
* Update a few comments in the validator-sets pallet
* Send/Recv Participation one at a time
Sending all, then attempting to receive all in an expected order, wasn't working
even with notable delays between sending messages. This points to the mempool
not working as expected...
* Correct ThresholdKeys serialization in modular-frost test
* Updating existing TX size limit test for the new DKG parameters
* Increase time allowed for the DKG on the GH CI
* Correct construction of signature_participants in serai-client tests
Fault identified by akil.
* Further contextualize DkgConfirmer by ValidatorSet
Caught by a safety check we wouldn't reuse preprocesses across messages. That
raises the question of we were prior reusing preprocesses (reusing keys)?
Except that'd have caused a variety of signing failures (suggesting we had some
staggered timing avoiding it in practice but yes, this was possible in theory).
* Add necessary calls to set_embedded_elliptic_curve_key in coordinator set rotation tests
* Correct shimmed setting of a secq256k1 key
* cargo fmt
* Don't use `[0; 32]` for the embedded keys in the coordinator rotation test
The key_gen function expects the random values already decided.
* Big-endian secq256k1 scalars
Also restores the prior, safer, Encryption::register function.
Makes RemoveParticipantDueToDkg a voted-on event instead of a Provided.
This removes the requirement for offline parties to be able to fully validate
blame, yet unfortunately lets an dishonest supermajority have an honest node
label any arbitrary node as dishonest.
Corrects a variety of `.i(...)` calls which panicked when they shouldn't have.
Cleans up a couple no-longer-used storage values.
With a DKG removal comes a reduction in the amount of participants which was
ignored by re-attempts.
Now, we determine n/i based on the parties removed, and deterministically
obtain the context of who was removd.
* 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
* Update ValidatorSets with a remove_participant call
* Add DkgRemoval, a sign machine for producing the relevant MuSig signatures
* Don't use position-dependent u8s yet Public when removing validators from the DKG
* Add DkgRemovalPreprocess, DkgRemovalShares
Implementation is via a new publish_tributary_tx lambda.
This is code is a copy-pasted mess which will need to be cleaned up.
* Only allow non-removed validators to vote for removals
Otherwise, it's risked that the remaining validators fall below 67% of the
original set.
* Correct publish_serai_tx, which was prior publish_set_keys in practice
This mirrors how Provided TXs handle topics.
Now, instead of managing a global nonce stream, we can use items such as plan
IDs as topics.
This massively benefits re-attempts, as else we'd need a NOP TX to clear unused
nonces.
* 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.
* Have processor report errors during the DKG to the coordinator
* Add RemoveParticipant, InvalidDkgShare to coordinator
* Route DKG blame around coordinator
* Allow public construction of AdditionalBlameMachine
Necessary for upcoming work on handling DKG blame in the processor and
coordinator.
Additionally fixes a publicly reachable panic when commitments parsed with one
ThresholdParams are used in a machine using another set of ThresholdParams.
Renames InvalidProofOfKnowledge to InvalidCommitments.
* Remove unused error from dleq
* Implement support for VerifyBlame in the processor
* Have coordinator send the processor share message relevant to Blame
* Remove desync between processors reporting InvalidShare and ones reporting GeneratedKeyPair
* Route blame on sign between processor and coordinator
Doesn't yet act on it in coordinator.
* Move txn usage as needed for stable Rust to build
* Correct InvalidDkgShare serialization
* 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
* initial staking pallet
* add staking pallet to runtime
* support session rotation for serai
* optimizations & cleaning
* fix deny
* add serai network to initial networks
* a few tweaks & comments
* fix some pr comments
* Rewrite validator-sets with logarithmic algorithms
Uses the fact the underlying DB is sorted to achieve sorting of potential
validators by stake.
Removes release of deallocated stake for now.
---------
Co-authored-by: Luke Parker <lukeparker5132@gmail.com>
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.
It was a piece of duplicated data used to achieve context-less
de)serialization. This new Vec code is a bit tricker to first read, yet overall
clean and removes a potential fault.
Saves 2 bytes from DkgShares messages.
See prior commit message for more info.
With the plan for the batch sign ID to be just 5 bytes (potentially 4), this
does incur a +5 bytes cost compared to the ExternalBlock system *even in the
standard case*. The simplicity remains preferred at this time.
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.
They used &mut self to prevent execution at the same time. This uses a lock
over the channel to achieve the same security, without requiring a lock over
the entire tributary.
This fixes post-provided Provided transactions. sync_block waited for the TX to
be provided, yet it never would as sync_block held a mutable reference over the
entire Tributary, preventing any other read/write operations of any scope.
A timeout increased (bc2f23f72b) due to this bug
not being identified has been decreased back, thankfully.
Also shims in basic support for Completed, which was the WIP before this bug
was identified.
* add slash tx
* ignore unsigned tx replays
* verify that provided evidence is valid
* fix clippy + fmt
* move application tx handling to another module
* partially handle the tendermint txs
* fix pr comments
* support unsigned app txs
* add slash target to the votes
* enforce provided, unsigned, signed tx ordering within a block
* bug fixes
* add unit test for tendermint txs
* bug fixes
* update tests for tendermint txs
* add tx ordering test
* tidy up tx ordering test
* cargo +nightly fmt
* Misc fixes from rebasing
* Finish resolving clippy
* Remove sha3 from tendermint-machine
* Resolve a DoS in SlashEvidence's read
Also moves Evidence from Vec<Message> to (Message, Option<Message>). That
should meet all requirements while being a bit safer.
* Make lazy_static a dev-depend for tributary
* Various small tweaks
One use of sort was inefficient, sorting unsigned || signed when unsigned was
already properly sorted. Given how the unsigned TXs were given a nonce of 0, an
unstable sort may swap places with an unsigned TX and a signed TX with a nonce
of 0 (leading to a faulty block).
The extra protection added here sorts signed, then concats.
* Fix Tributary tests I broke, start review on tendermint/tx.rs
* Finish reviewing everything outside tests and empty_signature
* Remove empty_signature
empty_signature led to corrupted local state histories. Unfortunately, the API
is only sane with a signature.
We now use the actual signature, which risks creating a signature over a
malicious message if we have ever have an invariant producing malicious
messages. Prior, we only signed the message after the local machine confirmed
it was okay per the local view of consensus.
This is tolerated/preferred over a corrupt state history since production of
such messages is already an invariant. TODOs are added to make handling of this
theoretical invariant further robust.
* Remove async_sequential for tokio::test
There was no competition for resources forcing them to be run sequentially.
* Modify block order test to be statistically significant without multiple runs
* Clean tests
---------
Co-authored-by: Luke Parker <lukeparker5132@gmail.com>
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.
Impls a LocalP2p for testing.
Moves rebroadcasting into Tendermint, since it's what knows if a message is
fully valid + original.
Removes TributarySpec::validators() HashMap, as its non-determinism caused
different instances to have different round robin schedules. It was already
prior moved to a Vec for this issue, so I'm unsure why this remnant existed.
Also renames the GH no-std workflow from the prior commit.
Necessary as our Tributary chains needed to agree when a Serai block has
occurred, and when a Monero block has occurred. Since those could happen at the
same time, some validators may put SeraiBlock before ExternalBlock and vice
versa, causing a chain halt. Now they can have distinct ordering queues.
The existing code was almost entirely applicable. It just needed to be scoped
with an ID. While the handle function is now a bit convoluted, I don't see a
better option.
