use core::ops::Deref;
use std::collections::HashMap;
use zeroize::Zeroizing;
use rand_core::OsRng;
use ciphersuite::{group::GroupEncoding, Ciphersuite, Ristretto};
use frost::dkg::Participant;
use scale::{Encode, Decode};
use serai_client::{Signature, validator_sets::primitives::KeyPair};
use tributary::{Signed, TransactionKind, TransactionTrait};
use processor_messages::{
key_gen::{self, KeyGenId},
coordinator::{self, SubstrateSignableId, SubstrateSignId},
sign::{self, SignId},
};
use serai_db::*;
use crate::{
processors::Processors,
tributary::{
*,
signing_protocol::DkgConfirmer,
scanner::{
RecognizedIdType, RIDTrait, PublishSeraiTransaction, PTTTrait, TributaryBlockHandler,
},
},
P2p,
};
pub fn dkg_confirmation_nonces(
key: &Zeroizing<<Ristretto as Ciphersuite>::F>,
spec: &TributarySpec,
txn: &mut impl DbTxn,
attempt: u32,
) -> [u8; 64] {
DkgConfirmer::new(key, spec, txn, attempt)
.expect("getting DKG confirmation nonces for unknown attempt")
.preprocess()
}
pub fn generated_key_pair<D: Db>(
txn: &mut D::Transaction<'_>,
key: &Zeroizing<<Ristretto as Ciphersuite>::F>,
spec: &TributarySpec,
key_pair: &KeyPair,
attempt: u32,
) -> Result<[u8; 32], Participant> {
DkgKeyPair::set(txn, spec.genesis(), attempt, key_pair);
KeyToDkgAttempt::set(txn, key_pair.0 .0, &attempt);
let preprocesses = ConfirmationNonces::get(txn, spec.genesis(), attempt).unwrap();
DkgConfirmer::new(key, spec, txn, attempt)
.expect("claiming to have generated a key pair for an unrecognized attempt")
.share(preprocesses, key_pair)
}
fn unflatten(
spec: &TributarySpec,
removed: &[<Ristretto as Ciphersuite>::G],
data: &mut HashMap<Participant, Vec<u8>>,
) {
for (validator, _) in spec.validators() {
let Some(range) = spec.i(removed, validator) else { continue };
let Some(all_segments) = data.remove(&range.start) else {
continue;
};
let mut data_vec = Vec::<_>::decode(&mut all_segments.as_slice()).unwrap();
for i in u16::from(range.start) .. u16::from(range.end) {
let i = Participant::new(i).unwrap();
data.insert(i, data_vec.remove(0));
}
}
}
impl<
D: Db,
T: DbTxn,
Pro: Processors,
PST: PublishSeraiTransaction,
PTT: PTTTrait,
RID: RIDTrait,
P: P2p,
> TributaryBlockHandler<'_, D, T, Pro, PST, PTT, RID, P>
{
fn accumulate(
&mut self,
removed: &[<Ristretto as Ciphersuite>::G],
data_spec: &DataSpecification,
signer: <Ristretto as Ciphersuite>::G,
data: &Vec<u8>,
) -> Accumulation {
log::debug!("accumulating entry for {:?} attempt #{}", &data_spec.topic, &data_spec.attempt);
let genesis = self.spec.genesis();
if DataDb::get(self.txn, genesis, data_spec, &signer.to_bytes()).is_some() {
panic!("accumulating data for a participant multiple times");
}
let signer_shares = {
let Some(signer_i) = self.spec.i(removed, signer) else {
log::warn!("accumulating data from {} who was removed", hex::encode(signer.to_bytes()));
return Accumulation::NotReady;
};
u16::from(signer_i.end) - u16::from(signer_i.start)
};
let prior_received = DataReceived::get(self.txn, genesis, data_spec).unwrap_or_default();
let now_received = prior_received + signer_shares;
DataReceived::set(self.txn, genesis, data_spec, &now_received);
DataDb::set(self.txn, genesis, data_spec, &signer.to_bytes(), data);
let received_range = (prior_received + 1) ..= now_received;
if (data_spec.label == Label::Preprocess) &&
received_range.contains(&self.spec.t()) &&
(data_spec.topic != Topic::DkgConfirmation)
{
assert_eq!(AttemptDb::attempt(self.txn, genesis, data_spec.topic), Some(data_spec.attempt));
ReattemptDb::schedule_reattempt(self.txn, genesis, self.block_number, data_spec.topic);
}
let needs_everyone =
(data_spec.topic == Topic::Dkg) || (data_spec.topic == Topic::DkgConfirmation);
let needed = if needs_everyone { self.spec.n(removed) } else { self.spec.t() };
if received_range.contains(&needed) {
log::debug!(
"accumulation for entry {:?} attempt #{} is ready",
&data_spec.topic,
&data_spec.attempt
);
let mut data = HashMap::new();
for validator in self.spec.validators().iter().map(|validator| validator.0) {
let Some(i) = self.spec.i(removed, validator) else { continue };
data.insert(
i.start,
if let Some(data) = DataDb::get(self.txn, genesis, data_spec, &validator.to_bytes()) {
data
} else {
continue;
},
);
}
assert_eq!(data.len(), usize::from(needed));
if let Some(i) = self.spec.i(removed, Ristretto::generator() * self.our_key.deref()) {
if data.remove(&i.start).is_some() {
return Accumulation::Ready(DataSet::Participating(data));
}
}
return Accumulation::Ready(DataSet::NotParticipating);
}
Accumulation::NotReady
}
fn handle_data(
&mut self,
removed: &[<Ristretto as Ciphersuite>::G],
data_spec: &DataSpecification,
bytes: &Vec<u8>,
signed: &Signed,
) -> Accumulation {
let genesis = self.spec.genesis();
let Some(curr_attempt) = AttemptDb::attempt(self.txn, genesis, data_spec.topic) else {
self.fatal_slash(signed.signer.to_bytes(), "published data for ID without an attempt");
return Accumulation::NotReady;
};
if DataDb::get(self.txn, genesis, data_spec, &signed.signer.to_bytes()).is_some() {
self.fatal_slash(signed.signer.to_bytes(), "published data multiple times");
return Accumulation::NotReady;
}
if data_spec.attempt < curr_attempt {
log::debug!(
"dated attempt published onto tributary for topic {:?} (used attempt {}, current {})",
data_spec.topic,
data_spec.attempt,
curr_attempt
);
return Accumulation::NotReady;
}
if data_spec.attempt > curr_attempt {
self.fatal_slash(
signed.signer.to_bytes(),
"published data with an attempt which hasn't started",
);
return Accumulation::NotReady;
}
self.accumulate(removed, data_spec, signed.signer, bytes)
}
fn check_sign_data_len(
&mut self,
removed: &[<Ristretto as Ciphersuite>::G],
signer: <Ristretto as Ciphersuite>::G,
len: usize,
) -> Result<(), ()> {
let Some(signer_i) = self.spec.i(removed, signer) else {
self.fatal_slash(signer.to_bytes(), "signer participated despite being removed");
Err(())?
};
if len != usize::from(u16::from(signer_i.end) - u16::from(signer_i.start)) {
self.fatal_slash(
signer.to_bytes(),
"signer published a distinct amount of sign data than they had shares",
);
Err(())?;
}
Ok(())
}
pub(crate) async fn handle_application_tx(&mut self, tx: Transaction) {
let genesis = self.spec.genesis();
if let TransactionKind::Signed(_, signed) = tx.kind() {
if FatallySlashed::get(self.txn, genesis, signed.signer.to_bytes()).is_some() {
return;
}
}
match tx {
Transaction::RemoveParticipantDueToDkg { participant, signed } => {
if self.spec.i(&[], participant).is_none() {
self.fatal_slash(
participant.to_bytes(),
"RemoveParticipantDueToDkg vote for non-validator",
);
return;
}
let participant = participant.to_bytes();
let signer = signed.signer.to_bytes();
assert!(
VotedToRemove::get(self.txn, genesis, signer, participant).is_none(),
"VotedToRemove multiple times despite a single nonce being allocated",
);
VotedToRemove::set(self.txn, genesis, signer, participant, &());
let prior_votes = VotesToRemove::get(self.txn, genesis, participant).unwrap_or(0);
let signer_votes =
self.spec.i(&[], signed.signer).expect("signer wasn't a validator for this network?");
let new_votes = prior_votes + u16::from(signer_votes.end) - u16::from(signer_votes.start);
VotesToRemove::set(self.txn, genesis, participant, &new_votes);
if ((prior_votes + 1) ..= new_votes).contains(&self.spec.t()) {
self.fatal_slash(participant, "RemoveParticipantDueToDkg vote")
}
}
Transaction::DkgCommitments { attempt, commitments, signed } => {
let Some(removed) = removed_as_of_dkg_attempt(self.txn, genesis, attempt) else {
self.fatal_slash(signed.signer.to_bytes(), "DkgCommitments with an unrecognized attempt");
return;
};
let Ok(()) = self.check_sign_data_len(&removed, signed.signer, commitments.len()) else {
return;
};
let data_spec = DataSpecification { topic: Topic::Dkg, label: Label::Preprocess, attempt };
match self.handle_data(&removed, &data_spec, &commitments.encode(), &signed) {
Accumulation::Ready(DataSet::Participating(mut commitments)) => {
log::info!("got all DkgCommitments for {}", hex::encode(genesis));
unflatten(self.spec, &removed, &mut commitments);
self
.processors
.send(
self.spec.set().network,
key_gen::CoordinatorMessage::Commitments {
id: KeyGenId { session: self.spec.set().session, attempt },
commitments,
},
)
.await;
}
Accumulation::Ready(DataSet::NotParticipating) => {
assert!(
removed.contains(&(Ristretto::generator() * self.our_key.deref())),
"NotParticipating in a DkgCommitments we weren't removed for"
);
}
Accumulation::NotReady => {}
}
}
Transaction::DkgShares { attempt, mut shares, confirmation_nonces, signed } => {
let Some(removed) = removed_as_of_dkg_attempt(self.txn, genesis, attempt) else {
self.fatal_slash(signed.signer.to_bytes(), "DkgShares with an unrecognized attempt");
return;
};
let not_participating = removed.contains(&(Ristretto::generator() * self.our_key.deref()));
let Ok(()) = self.check_sign_data_len(&removed, signed.signer, shares.len()) else {
return;
};
let Some(sender_i) = self.spec.i(&removed, signed.signer) else {
self.fatal_slash(
signed.signer.to_bytes(),
"DkgShares for a DKG they aren't participating in",
);
return;
};
let sender_is_len = u16::from(sender_i.end) - u16::from(sender_i.start);
for shares in &shares {
if shares.len() != (usize::from(self.spec.n(&removed) - sender_is_len)) {
self.fatal_slash(signed.signer.to_bytes(), "invalid amount of DKG shares");
return;
}
}
for (from_offset, shares) in shares.iter().enumerate() {
let from =
Participant::new(u16::from(sender_i.start) + u16::try_from(from_offset).unwrap())
.unwrap();
for (to_offset, share) in shares.iter().enumerate() {
let mut to = u16::try_from(to_offset).unwrap() + 1;
if to >= u16::from(sender_i.start) {
to += u16::from(sender_i.end) - u16::from(sender_i.start);
}
let to = Participant::new(to).unwrap();
DkgShare::set(self.txn, genesis, from.into(), to.into(), share);
}
}
let our_shares = if let Some(our_i) =
self.spec.i(&removed, Ristretto::generator() * self.our_key.deref())
{
if sender_i == our_i {
vec![]
} else {
let mut our_i_pos = u16::from(our_i.start) - 1;
if u16::from(our_i.start) > u16::from(sender_i.start) {
our_i_pos -= sender_is_len;
}
let our_i_pos = usize::from(our_i_pos);
shares
.iter_mut()
.map(|shares| {
shares
.drain(
our_i_pos ..
(our_i_pos + usize::from(u16::from(our_i.end) - u16::from(our_i.start))),
)
.collect::<Vec<_>>()
})
.collect()
}
} else {
assert!(
not_participating,
"we didn't have an i while handling DkgShares we weren't removed for"
);
vec![]
};
drop(shares);
let data_spec = DataSpecification { topic: Topic::Dkg, label: Label::Share, attempt };
let encoded_data = (confirmation_nonces.to_vec(), our_shares.encode()).encode();
match self.handle_data(&removed, &data_spec, &encoded_data, &signed) {
Accumulation::Ready(DataSet::Participating(confirmation_nonces_and_shares)) => {
log::info!("got all DkgShares for {}", hex::encode(genesis));
let mut confirmation_nonces = HashMap::new();
let mut shares = HashMap::new();
for (participant, confirmation_nonces_and_shares) in confirmation_nonces_and_shares {
let (these_confirmation_nonces, these_shares) =
<(Vec<u8>, Vec<u8>)>::decode(&mut confirmation_nonces_and_shares.as_slice())
.unwrap();
confirmation_nonces.insert(participant, these_confirmation_nonces);
shares.insert(participant, these_shares);
}
ConfirmationNonces::set(self.txn, genesis, attempt, &confirmation_nonces);
let mut expanded_shares = vec![];
for (sender_start_i, shares) in shares {
let shares: Vec<Vec<Vec<u8>>> = Vec::<_>::decode(&mut shares.as_slice()).unwrap();
for (sender_i_offset, our_shares) in shares.into_iter().enumerate() {
for (our_share_i, our_share) in our_shares.into_iter().enumerate() {
if expanded_shares.len() <= our_share_i {
expanded_shares.push(HashMap::new());
}
expanded_shares[our_share_i].insert(
Participant::new(
u16::from(sender_start_i) + u16::try_from(sender_i_offset).unwrap(),
)
.unwrap(),
our_share,
);
}
}
}
self
.processors
.send(
self.spec.set().network,
key_gen::CoordinatorMessage::Shares {
id: KeyGenId { session: self.spec.set().session, attempt },
shares: expanded_shares,
},
)
.await;
}
Accumulation::Ready(DataSet::NotParticipating) => {
assert!(not_participating, "NotParticipating in a DkgShares we weren't removed for");
}
Accumulation::NotReady => {}
}
}
Transaction::InvalidDkgShare { attempt, accuser, faulty, blame, signed } => {
let Some(removed) = removed_as_of_dkg_attempt(self.txn, genesis, attempt) else {
self
.fatal_slash(signed.signer.to_bytes(), "InvalidDkgShare with an unrecognized attempt");
return;
};
let Some(range) = self.spec.i(&removed, signed.signer) else {
self.fatal_slash(
signed.signer.to_bytes(),
"InvalidDkgShare for a DKG they aren't participating in",
);
return;
};
if !range.contains(&accuser) {
self.fatal_slash(
signed.signer.to_bytes(),
"accused with a Participant index which wasn't theirs",
);
return;
}
if range.contains(&faulty) {
self.fatal_slash(signed.signer.to_bytes(), "accused self of having an InvalidDkgShare");
return;
}
let Some(share) = DkgShare::get(self.txn, genesis, accuser.into(), faulty.into()) else {
self.fatal_slash(
signed.signer.to_bytes(),
"InvalidDkgShare had a non-existent faulty participant",
);
return;
};
self
.processors
.send(
self.spec.set().network,
key_gen::CoordinatorMessage::VerifyBlame {
id: KeyGenId { session: self.spec.set().session, attempt },
accuser,
accused: faulty,
share,
blame,
},
)
.await;
}
Transaction::DkgConfirmed { attempt, confirmation_share, signed } => {
let Some(removed) = removed_as_of_dkg_attempt(self.txn, genesis, attempt) else {
self.fatal_slash(signed.signer.to_bytes(), "DkgConfirmed with an unrecognized attempt");
return;
};
let data_spec =
DataSpecification { topic: Topic::DkgConfirmation, label: Label::Share, attempt };
match self.handle_data(&removed, &data_spec, &confirmation_share.to_vec(), &signed) {
Accumulation::Ready(DataSet::Participating(shares)) => {
log::info!("got all DkgConfirmed for {}", hex::encode(genesis));
let Some(removed) = removed_as_of_dkg_attempt(self.txn, genesis, attempt) else {
panic!(
"DkgConfirmed for everyone yet didn't have the removed parties for this attempt",
);
};
let preprocesses = ConfirmationNonces::get(self.txn, genesis, attempt).unwrap();
let key_pair = DkgKeyPair::get(self.txn, genesis, attempt).expect(
"in DkgConfirmed handling, which happens after everyone \
(including us) fires DkgConfirmed, yet no confirming key pair",
);
let mut confirmer = DkgConfirmer::new(self.our_key, self.spec, self.txn, attempt)
.expect("confirming DKG for unrecognized attempt");
let sig = match confirmer.complete(preprocesses, &key_pair, shares) {
Ok(sig) => sig,
Err(p) => {
let mut tx = Transaction::RemoveParticipantDueToDkg {
participant: self.spec.reverse_lookup_i(&removed, p).unwrap(),
signed: Transaction::empty_signed(),
};
tx.sign(&mut OsRng, genesis, self.our_key);
self.publish_tributary_tx.publish_tributary_tx(tx).await;
return;
}
};
DkgLocallyCompleted::set(self.txn, genesis, &());
self
.publish_serai_tx
.publish_set_keys(
self.db,
self.spec.set(),
removed.into_iter().map(|key| key.to_bytes().into()).collect(),
key_pair,
Signature(sig),
)
.await;
}
Accumulation::Ready(DataSet::NotParticipating) => {
panic!("wasn't a participant in DKG confirmination shares")
}
Accumulation::NotReady => {}
}
}
Transaction::CosignSubstrateBlock(hash) => {
AttemptDb::recognize_topic(
self.txn,
genesis,
Topic::SubstrateSign(SubstrateSignableId::CosigningSubstrateBlock(hash)),
);
let block_number = SeraiBlockNumber::get(self.txn, hash)
.expect("CosignSubstrateBlock yet didn't save Serai block number");
let msg = coordinator::CoordinatorMessage::CosignSubstrateBlock {
id: SubstrateSignId {
session: self.spec.set().session,
id: SubstrateSignableId::CosigningSubstrateBlock(hash),
attempt: 0,
},
block_number,
};
self.processors.send(self.spec.set().network, msg).await;
}
Transaction::Batch { block: _, batch } => {
AttemptDb::recognize_topic(
self.txn,
genesis,
Topic::SubstrateSign(SubstrateSignableId::Batch(batch)),
);
self
.recognized_id
.recognized_id(
self.spec.set(),
genesis,
RecognizedIdType::Batch,
batch.to_le_bytes().to_vec(),
)
.await;
}
Transaction::SubstrateBlock(block) => {
let plan_ids = PlanIds::get(self.txn, &genesis, block).expect(
"synced a tributary block finalizing a substrate block in a provided transaction \
despite us not providing that transaction",
);
for id in plan_ids {
AttemptDb::recognize_topic(self.txn, genesis, Topic::Sign(id));
self
.recognized_id
.recognized_id(self.spec.set(), genesis, RecognizedIdType::Plan, id.to_vec())
.await;
}
}
Transaction::SubstrateSign(data) => {
let Some(removed) =
crate::tributary::removed_as_of_set_keys(self.txn, self.spec.set(), genesis)
else {
self.fatal_slash(
data.signed.signer.to_bytes(),
"signing despite not having set keys on substrate",
);
return;
};
let signer = data.signed.signer;
let Ok(()) = self.check_sign_data_len(&removed, signer, data.data.len()) else {
return;
};
let expected_len = match data.label {
Label::Preprocess => 64,
Label::Share => 32,
};
for data in &data.data {
if data.len() != expected_len {
self.fatal_slash(
signer.to_bytes(),
"unexpected length data for substrate signing protocol",
);
return;
}
}
let data_spec = DataSpecification {
topic: Topic::SubstrateSign(data.plan),
label: data.label,
attempt: data.attempt,
};
let Accumulation::Ready(DataSet::Participating(mut results)) =
self.handle_data(&removed, &data_spec, &data.data.encode(), &data.signed)
else {
return;
};
unflatten(self.spec, &removed, &mut results);
let id = SubstrateSignId {
session: self.spec.set().session,
id: data.plan,
attempt: data.attempt,
};
let msg = match data.label {
Label::Preprocess => coordinator::CoordinatorMessage::SubstratePreprocesses {
id,
preprocesses: results.into_iter().map(|(v, p)| (v, p.try_into().unwrap())).collect(),
},
Label::Share => coordinator::CoordinatorMessage::SubstrateShares {
id,
shares: results.into_iter().map(|(v, p)| (v, p.try_into().unwrap())).collect(),
},
};
self.processors.send(self.spec.set().network, msg).await;
}
Transaction::Sign(data) => {
let Some(removed) =
crate::tributary::removed_as_of_set_keys(self.txn, self.spec.set(), genesis)
else {
self.fatal_slash(
data.signed.signer.to_bytes(),
"signing despite not having set keys on substrate",
);
return;
};
let Ok(()) = self.check_sign_data_len(&removed, data.signed.signer, data.data.len()) else {
return;
};
let data_spec = DataSpecification {
topic: Topic::Sign(data.plan),
label: data.label,
attempt: data.attempt,
};
if let Accumulation::Ready(DataSet::Participating(mut results)) =
self.handle_data(&removed, &data_spec, &data.data.encode(), &data.signed)
{
unflatten(self.spec, &removed, &mut results);
let id =
SignId { session: self.spec.set().session, id: data.plan, attempt: data.attempt };
self
.processors
.send(
self.spec.set().network,
match data.label {
Label::Preprocess => {
sign::CoordinatorMessage::Preprocesses { id, preprocesses: results }
}
Label::Share => sign::CoordinatorMessage::Shares { id, shares: results },
},
)
.await;
}
}
Transaction::SignCompleted { plan, tx_hash, first_signer, signature: _ } => {
log::info!(
"on-chain SignCompleted claims {} completes {}",
hex::encode(&tx_hash),
hex::encode(plan)
);
if AttemptDb::attempt(self.txn, genesis, Topic::Sign(plan)).is_none() {
self.fatal_slash(first_signer.to_bytes(), "claimed an unrecognized plan was completed");
return;
};
let msg = sign::CoordinatorMessage::Completed {
session: self.spec.set().session,
id: plan,
tx: tx_hash,
};
self.processors.send(self.spec.set().network, msg).await;
}
Transaction::SlashReport(points, signed) => {
let signer_range = self.spec.i(&[], signed.signer).unwrap();
let signer_len = u16::from(signer_range.end) - u16::from(signer_range.start);
if points.len() != (self.spec.validators().len() - 1) {
self.fatal_slash(
signed.signer.to_bytes(),
"submitted a distinct amount of slash points to participants",
);
return;
}
if SlashReports::get(self.txn, genesis, signed.signer.to_bytes()).is_some() {
self.fatal_slash(signed.signer.to_bytes(), "submitted multiple slash points");
return;
}
SlashReports::set(self.txn, genesis, signed.signer.to_bytes(), &points);
let prior_reported = SlashReported::get(self.txn, genesis).unwrap_or(0);
let now_reported = prior_reported + signer_len;
SlashReported::set(self.txn, genesis, &now_reported);
if (prior_reported < self.spec.t()) && (now_reported >= self.spec.t()) {
SlashReportCutOff::set(
self.txn,
genesis,
&(u64::from(self.block_number) +
((30 * 60 * 1000) / u64::from(tributary::tendermint::TARGET_BLOCK_TIME))),
);
}
}
}
}
}