SlashReport signing and signature publication

Cargo.lock

@@ -8731,6 +8731,7 @@ dependencies = [
  "rand_core",
  "serai-db",
  "serai-in-instructions-primitives",
+ "serai-primitives",
  "serai-processor-frost-attempt-manager",
  "serai-processor-messages",
  "serai-processor-primitives",

processor/messages/src/lib.rs

@@ -7,9 +7,9 @@ use borsh::{BorshSerialize, BorshDeserialize};
 use dkg::Participant;
 
 use serai_primitives::BlockHash;
-use in_instructions_primitives::{Batch, SignedBatch};
-use coins_primitives::OutInstructionWithBalance;
 use validator_sets_primitives::{Session, KeyPair, Slash};
+use coins_primitives::OutInstructionWithBalance;
+use in_instructions_primitives::{Batch, SignedBatch};
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, BorshSerialize, BorshDeserialize)]
 pub struct SubstrateContext {
@@ -84,7 +84,7 @@ pub mod sign {
   pub enum VariantSignId {
     Cosign([u8; 32]),
     Batch(u32),
-    SlashReport([u8; 32]),
+    SlashReport(Session),
     Transaction([u8; 32]),
   }
   impl fmt::Debug for VariantSignId {
@@ -94,10 +94,9 @@ pub mod sign {
           f.debug_struct("VariantSignId::Cosign").field("0", &hex::encode(cosign)).finish()
         }
         Self::Batch(batch) => f.debug_struct("VariantSignId::Batch").field("0", &batch).finish(),
-        Self::SlashReport(slash_report) => f
-          .debug_struct("VariantSignId::SlashReport")
-          .field("0", &hex::encode(slash_report))
-          .finish(),
+        Self::SlashReport(session) => {
+          f.debug_struct("VariantSignId::SlashReport").field("0", &session).finish()
+        }
         Self::Transaction(tx) => {
           f.debug_struct("VariantSignId::Transaction").field("0", &hex::encode(tx)).finish()
         }

processor/scanner/src/lib.rs

@@ -21,7 +21,7 @@ pub use lifetime::LifetimeStage;
 // Database schema definition and associated functions.
 mod db;
 use db::ScannerGlobalDb;
-pub use db::{BatchesToSign, AcknowledgedBatches, CompletedEventualities};
+pub use db::{Batches, BatchesToSign, AcknowledgedBatches, CompletedEventualities};
 // Task to index the blockchain, ensuring we don't reorganize finalized blocks.
 mod index;
 // Scans blocks for received coins.

processor/signers/Cargo.toml

@@ -31,6 +31,7 @@ frost-schnorrkel = { path = "../../crypto/schnorrkel", default-features = false
 scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["std"] }
 borsh = { version = "1", default-features = false, features = ["std", "derive", "de_strict_order"] }
 
+serai-primitives = { path = "../../substrate/primitives", default-features = false, features = ["std"] }
 serai-validator-sets-primitives = { path = "../../substrate/validator-sets/primitives", default-features = false, features = ["std"] }
 serai-in-instructions-primitives = { path = "../../substrate/in-instructions/primitives", default-features = false, features = ["std"] }
 

processor/signers/src/coordinator/mod.rs

@@ -1,14 +1,9 @@
+use scale::Decode;
 use serai_db::{DbTxn, Db};
 
 use primitives::task::ContinuallyRan;
 
-use crate::{
-  db::{
-    RegisteredKeys, CosignerToCoordinatorMessages, BatchSignerToCoordinatorMessages,
-    SlashReportSignerToCoordinatorMessages, TransactionSignerToCoordinatorMessages,
-  },
-  Coordinator,
-};
+use crate::{db::*, Coordinator};
 
 mod db;
 
@@ -30,6 +25,7 @@ impl<D: Db, C: Coordinator> ContinuallyRan for CoordinatorTask<D, C> {
     let mut iterated = false;
 
     for session in RegisteredKeys::get(&self.db).unwrap_or(vec![]) {
+      // Publish the messages generated by this key's signers
       loop {
         let mut txn = self.db.txn();
         let Some(msg) = CosignerToCoordinatorMessages::try_recv(&mut txn, session) else {
@@ -93,6 +89,26 @@ impl<D: Db, C: Coordinator> ContinuallyRan for CoordinatorTask<D, C> {
 
         txn.commit();
       }
+
+      // If this session signed its slash report, publish its signature
+      {
+        let mut txn = self.db.txn();
+        if let Some(slash_report_signature) = SlashReportSignature::try_recv(&mut txn, session) {
+          iterated = true;
+
+          self
+            .coordinator
+            .publish_slash_report_signature(
+              <_>::decode(&mut slash_report_signature.as_slice()).unwrap(),
+            )
+            .await
+            .map_err(|e| {
+              format!("couldn't send slash report signature to the coordinator: {e:?}")
+            })?;
+
+          txn.commit();
+        }
+      }
     }
 
     // Publish the Batches

processor/signers/src/db.rs

@@ -17,6 +17,7 @@ db_channel! {
   SignersGlobal {
     Cosign: (session: Session) -> (u64, [u8; 32]),
     SlashReport: (session: Session) -> Vec<Slash>,
+    SlashReportSignature: (session: Session) -> Vec<u8>,
 
     CoordinatorToCosignerMessages: (session: Session) -> CoordinatorMessage,
     CosignerToCoordinatorMessages: (session: Session) -> ProcessorMessage,

processor/signers/src/lib.rs

@@ -10,8 +10,9 @@ use zeroize::Zeroizing;
 use ciphersuite::{group::GroupEncoding, Ciphersuite, Ristretto};
 use frost::dkg::{ThresholdCore, ThresholdKeys};
 
+use serai_primitives::Signature;
 use serai_validator_sets_primitives::{Session, Slash};
-use serai_in_instructions_primitives::SignedBatch;
+use serai_in_instructions_primitives::{Batch, SignedBatch};
 
 use serai_db::{DbTxn, Db};
 
@@ -19,6 +20,7 @@ use messages::sign::{VariantSignId, ProcessorMessage, CoordinatorMessage};
 
 use primitives::task::{Task, TaskHandle, ContinuallyRan};
 use scheduler::{Transaction, SignableTransaction, TransactionFor};
+use scanner::{ScannerFeed, Scheduler};
 
 mod wrapped_schnorrkel;
 pub(crate) use wrapped_schnorrkel::WrappedSchnorrkelMachine;
@@ -31,6 +33,9 @@ use coordinator::CoordinatorTask;
 mod batch;
 use batch::BatchSignerTask;
 
+mod slash_report;
+use slash_report::SlashReportSignerTask;
+
 mod transaction;
 use transaction::TransactionSignerTask;
 
@@ -51,6 +56,12 @@ pub trait Coordinator: 'static + Send + Sync {
 
   /// Publish a `SignedBatch`.
   async fn publish_signed_batch(&mut self, batch: SignedBatch) -> Result<(), Self::EphemeralError>;
+
+  /// Publish a slash report's signature.
+  async fn publish_slash_report_signature(
+    &mut self,
+    signature: Signature,
+  ) -> Result<(), Self::EphemeralError>;
 }
 
 /// An object capable of publishing a transaction.
@@ -81,12 +92,17 @@ struct Tasks {
 
 /// The signers used by a processor.
 #[allow(non_snake_case)]
-pub struct Signers<ST: SignableTransaction> {
+pub struct Signers<S: ScannerFeed, Sch: Scheduler<S>> {
   coordinator_handle: TaskHandle,
   tasks: HashMap<Session, Tasks>,
-  _ST: PhantomData<ST>,
+  _Sch: PhantomData<Sch>,
+  _S: PhantomData<S>,
 }
 
+type CiphersuiteFor<S, Sch> =
+  <<Sch as Scheduler<S>>::SignableTransaction as SignableTransaction>::Ciphersuite;
+type SignableTransactionFor<S, Sch> = <Sch as Scheduler<S>>::SignableTransaction;
+
 /*
   This is completely outside of consensus, so the worst that can happen is:
 
@@ -99,14 +115,14 @@ pub struct Signers<ST: SignableTransaction> {
   completion comes in *before* we registered a key, the signer will hold the signing protocol in
   memory until the session is retired entirely.
 */
-impl<ST: SignableTransaction> Signers<ST> {
+impl<S: ScannerFeed, Sch: Scheduler<S>> Signers<S, Sch> {
   /// Initialize the signers.
   ///
   /// This will spawn tasks for any historically registered keys.
   pub fn new(
     mut db: impl Db,
     coordinator: impl Coordinator,
-    publisher: &impl TransactionPublisher<TransactionFor<ST>>,
+    publisher: &impl TransactionPublisher<TransactionFor<SignableTransactionFor<S, Sch>>>,
   ) -> Self {
     /*
       On boot, perform any database cleanup which was queued.
@@ -120,8 +136,7 @@ impl<ST: SignableTransaction> Signers<ST> {
       let mut txn = db.txn();
       for (session, external_key_bytes) in db::ToCleanup::get(&txn).unwrap_or(vec![]) {
         let mut external_key_bytes = external_key_bytes.as_slice();
-        let external_key =
-          <ST::Ciphersuite as Ciphersuite>::read_G(&mut external_key_bytes).unwrap();
+        let external_key = CiphersuiteFor::<S, Sch>::read_G(&mut external_key_bytes).unwrap();
         assert!(external_key_bytes.is_empty());
 
         // Drain the Batches to sign
@@ -133,7 +148,12 @@ impl<ST: SignableTransaction> Signers<ST> {
 
         // Drain the transactions to sign
         // This will be fully populated by the scheduler before retiry
-        while scheduler::TransactionsToSign::<ST>::try_recv(&mut txn, &external_key).is_some() {}
+        while scheduler::TransactionsToSign::<SignableTransactionFor<S, Sch>>::try_recv(
+          &mut txn,
+          &external_key,
+        )
+        .is_some()
+        {}
 
         // Drain the completed Eventualities
         while scanner::CompletedEventualities::try_recv(&mut txn, &external_key).is_some() {}
@@ -170,11 +190,12 @@ impl<ST: SignableTransaction> Signers<ST> {
       while !buf.is_empty() {
         substrate_keys
           .push(ThresholdKeys::from(ThresholdCore::<Ristretto>::read(&mut buf).unwrap()));
-        external_keys
-          .push(ThresholdKeys::from(ThresholdCore::<ST::Ciphersuite>::read(&mut buf).unwrap()));
+        external_keys.push(ThresholdKeys::from(
+          ThresholdCore::<CiphersuiteFor<S, Sch>>::read(&mut buf).unwrap(),
+        ));
       }
 
-      // TODO: Cosigner and slash report signers
+      // TODO: Cosigner
 
       let (batch_task, batch_handle) = Task::new();
       tokio::spawn(
@@ -187,9 +208,15 @@ impl<ST: SignableTransaction> Signers<ST> {
         .continually_run(batch_task, vec![coordinator_handle.clone()]),
       );
 
+      let (slash_report_task, slash_report_handle) = Task::new();
+      tokio::spawn(
+        SlashReportSignerTask::<_, S>::new(db.clone(), session, substrate_keys.clone())
+          .continually_run(slash_report_task, vec![coordinator_handle.clone()]),
+      );
+
       let (transaction_task, transaction_handle) = Task::new();
       tokio::spawn(
-        TransactionSignerTask::<_, ST, _>::new(
+        TransactionSignerTask::<_, SignableTransactionFor<S, Sch>, _>::new(
           db.clone(),
           publisher.clone(),
           session,
@@ -203,13 +230,13 @@ impl<ST: SignableTransaction> Signers<ST> {
         Tasks {
           cosigner: todo!("TODO"),
           batch: batch_handle,
-          slash_report: todo!("TODO"),
+          slash_report: slash_report_handle,
           transaction: transaction_handle,
         },
       );
     }
 
-    Self { coordinator_handle, tasks, _ST: PhantomData }
+    Self { coordinator_handle, tasks, _Sch: PhantomData, _S: PhantomData }
   }
 
   /// Register a set of keys to sign with.
@@ -220,7 +247,7 @@ impl<ST: SignableTransaction> Signers<ST> {
     txn: &mut impl DbTxn,
     session: Session,
     substrate_keys: Vec<ThresholdKeys<Ristretto>>,
-    network_keys: Vec<ThresholdKeys<ST::Ciphersuite>>,
+    network_keys: Vec<ThresholdKeys<CiphersuiteFor<S, Sch>>>,
   ) {
     // Don't register already retired keys
     if Some(session.0) <= db::LatestRetiredSession::get(txn).map(|session| session.0) {
@@ -246,7 +273,8 @@ impl<ST: SignableTransaction> Signers<ST> {
   /// Retire the signers for a session.
   ///
   /// This MUST be called in order, for every session (even if we didn't register keys for this
-  /// session).
+  /// session). This MUST only be called after slash report publication, or after that process
+  /// times out (not once the key is done with regards to the external network).
   pub fn retire_session(
     &mut self,
     txn: &mut impl DbTxn,
@@ -324,7 +352,7 @@ impl<ST: SignableTransaction> Signers<ST> {
     txn.commit();
 
     if let Some(tasks) = self.tasks.get(&session) {
-      tasks.cosign.run_now();
+      tasks.cosigner.run_now();
     }
   }
 
@@ -335,9 +363,9 @@ impl<ST: SignableTransaction> Signers<ST> {
     &mut self,
     mut txn: impl DbTxn,
     session: Session,
-    slash_report: Vec<Slash>,
+    slash_report: &Vec<Slash>,
   ) {
-    db::SlashReport::send(&mut txn, session, &slash_report);
+    db::SlashReport::send(&mut txn, session, slash_report);
     txn.commit();
 
     if let Some(tasks) = self.tasks.get(&session) {

processor/signers/src/slash_report.rs

@@ -0,0 +1,120 @@
+use core::marker::PhantomData;
+
+use ciphersuite::Ristretto;
+use frost::dkg::ThresholdKeys;
+
+use scale::Encode;
+use serai_primitives::Signature;
+use serai_validator_sets_primitives::{
+  Session, ValidatorSet, SlashReport as SlashReportStruct, report_slashes_message,
+};
+
+use serai_db::{DbTxn, Db};
+
+use messages::sign::VariantSignId;
+
+use primitives::task::ContinuallyRan;
+use scanner::ScannerFeed;
+
+use frost_attempt_manager::*;
+
+use crate::{
+  db::{
+    SlashReport, SlashReportSignature, CoordinatorToSlashReportSignerMessages,
+    SlashReportSignerToCoordinatorMessages,
+  },
+  WrappedSchnorrkelMachine,
+};
+
+// Fetches slash_reportes to sign and signs them.
+#[allow(non_snake_case)]
+pub(crate) struct SlashReportSignerTask<D: Db, S: ScannerFeed> {
+  db: D,
+  _S: PhantomData<S>,
+
+  session: Session,
+  keys: Vec<ThresholdKeys<Ristretto>>,
+
+  has_slash_report: bool,
+  attempt_manager: AttemptManager<D, WrappedSchnorrkelMachine>,
+}
+
+impl<D: Db, S: ScannerFeed> SlashReportSignerTask<D, S> {
+  pub(crate) fn new(db: D, session: Session, keys: Vec<ThresholdKeys<Ristretto>>) -> Self {
+    let attempt_manager = AttemptManager::new(
+      db.clone(),
+      session,
+      keys.first().expect("creating a slash_report signer with 0 keys").params().i(),
+    );
+
+    Self { db, _S: PhantomData, session, keys, has_slash_report: false, attempt_manager }
+  }
+}
+
+#[async_trait::async_trait]
+impl<D: Db, S: ScannerFeed> ContinuallyRan for SlashReportSignerTask<D, S> {
+  async fn run_iteration(&mut self) -> Result<bool, String> {
+    let mut iterated = false;
+
+    // Check for the slash report to sign
+    if !self.has_slash_report {
+      let mut txn = self.db.txn();
+      let Some(slash_report) = SlashReport::try_recv(&mut txn, self.session) else {
+        return Ok(false);
+      };
+      // We only commit this upon successfully signing this slash report
+      drop(txn);
+      iterated = true;
+
+      self.has_slash_report = true;
+
+      let mut machines = Vec::with_capacity(self.keys.len());
+      {
+        let message = report_slashes_message(
+          &ValidatorSet { network: S::NETWORK, session: self.session },
+          &SlashReportStruct(slash_report.try_into().unwrap()),
+        );
+        for keys in &self.keys {
+          machines.push(WrappedSchnorrkelMachine::new(keys.clone(), message.clone()));
+        }
+      }
+      let mut txn = self.db.txn();
+      for msg in self.attempt_manager.register(VariantSignId::SlashReport(self.session), machines) {
+        SlashReportSignerToCoordinatorMessages::send(&mut txn, self.session, &msg);
+      }
+      txn.commit();
+    }
+
+    // Handle any messages sent to us
+    loop {
+      let mut txn = self.db.txn();
+      let Some(msg) = CoordinatorToSlashReportSignerMessages::try_recv(&mut txn, self.session)
+      else {
+        break;
+      };
+      iterated = true;
+
+      match self.attempt_manager.handle(msg) {
+        Response::Messages(msgs) => {
+          for msg in msgs {
+            SlashReportSignerToCoordinatorMessages::send(&mut txn, self.session, &msg);
+          }
+        }
+        Response::Signature { id, signature } => {
+          let VariantSignId::SlashReport(session) = id else {
+            panic!("SlashReportSignerTask signed a non-SlashReport")
+          };
+          assert_eq!(session, self.session);
+          // Drain the channel
+          SlashReport::try_recv(&mut txn, self.session).unwrap();
+          // Send the signature
+          SlashReportSignature::send(&mut txn, session, &Signature::from(signature).encode());
+        }
+      }
+
+      txn.commit();
+    }
+
+    Ok(iterated)
+  }
+}