Use a MuSig signature to publish validator set key pairs to Serai

The processor/coordinator flow still has to be rewritten.

substrate/client/src/serai/in_instructions.rs

@@ -33,7 +33,7 @@ impl Serai {
       .await
   }
 
-  pub fn execute_batch(&self, batch: SignedBatch) -> Encoded {
-    self.unsigned::<InInstructions, _>(&in_instructions::Call::<Runtime>::execute_batch { batch })
+  pub fn execute_batch(batch: SignedBatch) -> Encoded {
+    Self::unsigned::<InInstructions, _>(&in_instructions::Call::<Runtime>::execute_batch { batch })
   }
 }

substrate/client/src/serai/mod.rs

@@ -269,7 +269,7 @@ impl Serai {
       .map_err(SeraiError::RpcError)
   }
 
-  fn unsigned<P: 'static, C: Encode>(&self, call: &C) -> Encoded {
+  fn unsigned<P: 'static, C: Encode>(call: &C) -> Encoded {
     // TODO: Should Serai purge the old transaction code AND set this to 0/1?
     const TRANSACTION_VERSION: u8 = 4;
 

substrate/client/src/serai/validator_sets.rs

@@ -1,10 +1,12 @@
+use sp_core::sr25519::Signature;
+
 use serai_runtime::{validator_sets, ValidatorSets, Runtime};
 pub use validator_sets::primitives;
 use primitives::{ValidatorSet, ValidatorSetData, KeyPair};
 
-use subxt::tx::Payload;
+use subxt::utils::Encoded;
 
-use crate::{primitives::NetworkId, Serai, SeraiError, Composite, scale_value, scale_composite};
+use crate::{primitives::NetworkId, Serai, SeraiError, scale_value};
 
 const PALLET: &str = "ValidatorSets";
 
@@ -20,15 +22,6 @@ impl Serai {
       .await
   }
 
-  pub async fn get_vote_events(
-    &self,
-    block: [u8; 32],
-  ) -> Result<Vec<ValidatorSetsEvent>, SeraiError> {
-    self
-      .events::<ValidatorSets, _>(block, |event| matches!(event, ValidatorSetsEvent::Vote { .. }))
-      .await
-  }
-
   pub async fn get_key_gen_events(
     &self,
     block: [u8; 32],
@@ -52,17 +45,35 @@ impl Serai {
       .await
   }
 
+  pub async fn get_validator_set_musig_key(
+    &self,
+    set: ValidatorSet,
+  ) -> Result<Option<[u8; 32]>, SeraiError> {
+    self
+      .storage(
+        PALLET,
+        "MuSigKeys",
+        Some(vec![scale_value(set)]),
+        self.get_latest_block_hash().await?,
+      )
+      .await
+  }
+
   pub async fn get_keys(&self, set: ValidatorSet) -> Result<Option<KeyPair>, SeraiError> {
     self
       .storage(PALLET, "Keys", Some(vec![scale_value(set)]), self.get_latest_block_hash().await?)
       .await
   }
 
-  pub fn vote(network: NetworkId, key_pair: KeyPair) -> Payload<Composite<()>> {
-    Payload::new(
-      PALLET,
-      "vote",
-      scale_composite(validator_sets::Call::<Runtime>::vote { network, key_pair }),
-    )
+  pub fn set_validator_set_keys(
+    network: NetworkId,
+    key_pair: KeyPair,
+    signature: Signature,
+  ) -> Encoded {
+    Self::unsigned::<ValidatorSets, _>(&validator_sets::Call::<Runtime>::set_keys {
+      network,
+      key_pair,
+      signature,
+    })
   }
 }