Use proper messages for ValidatorSets/InInstructions pallet

Provides a DST, and associated metadata as beneficial.

Also utilizes MuSig's context to session-bind. Since set_keys_messages also
binds to set, this is semi-redundant, yet that's appreciated.

Cargo.lock

@@ -8780,6 +8780,7 @@ dependencies = [
  "ciphersuite",
  "dalek-ff-group",
  "dkg",
+ "dleq",
  "flexible-transcript",
  "minimal-ed448",
  "monero-generators",
@@ -10998,8 +10999,6 @@ dependencies = [
 name = "validator-sets-pallet"
 version = "0.1.0"
 dependencies = [
- "ciphersuite",
- "dkg",
  "frame-support",
  "frame-system",
  "hashbrown 0.13.2",
@@ -11015,11 +11014,14 @@ dependencies = [
 name = "validator-sets-primitives"
 version = "0.1.0"
 dependencies = [
+ "ciphersuite",
+ "dkg",
  "parity-scale-codec",
  "scale-info",
  "serai-primitives",
  "serde",
  "sp-core",
+ "sp-std 5.0.0",
  "zeroize",
 ]
 

crypto/dkg/Cargo.toml

@@ -37,7 +37,20 @@ rand_core = { version = "0.6", default-features = false, features = ["getrandom"
 ciphersuite = { path = "../ciphersuite", version = "0.3", default-features = false, features = ["ristretto"] }
 
 [features]
-std = ["thiserror", "rand_core/std", "std-shims/std", "ciphersuite/std", "multiexp/[batch, std]", "schnorr/std", "dleq/serialize"]
+std = [
+  "thiserror",
+  "rand_core/std",
+
+  "std-shims/std",
+
+  "ciphersuite/std",
+
+  "multiexp/batch",
+  "multiexp/std",
+
+  "schnorr/std",
+  "dleq/serialize"
+]
 serde = ["dep:serde"]
 tests = ["rand_core/getrandom"]
 default = ["std"]

processor/src/substrate_signer.rs

@@ -20,7 +20,7 @@ use log::{info, debug, warn};
 
 use serai_client::{
   primitives::BlockHash,
-  in_instructions::primitives::{Batch, SignedBatch},
+  in_instructions::primitives::{Batch, SignedBatch, batch_message},
 };
 
 use messages::{sign::SignId, coordinator::*};
@@ -253,7 +253,8 @@ impl<D: Db> SubstrateSigner<D> {
           Err(e) => todo!("malicious signer: {:?}", e),
         };
 
-        let (machine, share) = match machine.sign(preprocesses, &self.signable[&id.id].encode()) {
+        let (machine, share) =
+          match machine.sign(preprocesses, &batch_message(&self.signable[&id.id])) {
             Ok(res) => res,
             Err(e) => todo!("malicious signer: {:?}", e),
           };

processor/src/tests/substrate_signer.rs

@@ -9,7 +9,6 @@ use frost::{
   dkg::tests::{key_gen, clone_without},
 };
 
-use scale::Encode;
 use sp_application_crypto::{RuntimePublic, sr25519::Public};
 
 use serai_db::{DbTxn, Db, MemDb};
@@ -143,7 +142,7 @@ async fn test_substrate_signer() {
     {
       assert_eq!(signed_batch.batch, batch);
       assert!(Public::from_raw(actual_id.key.clone().try_into().unwrap())
-        .verify(&batch.encode(), &signed_batch.signature));
+        .verify(&batch_message(&batch), &signed_batch.signature));
     } else {
       panic!("didn't get signed batch back");
     }

substrate/client/tests/common/in_instructions.rs

@@ -1,12 +1,10 @@
-use scale::Encode;
-
 use sp_core::Pair;
 
 use serai_client::{
   primitives::insecure_pair_from_name,
   validator_sets::primitives::{Session, ValidatorSet},
   in_instructions::{
-    primitives::{Batch, SignedBatch},
+    primitives::{Batch, SignedBatch, batch_message},
     InInstructionsEvent,
   },
   Serai,
@@ -32,7 +30,7 @@ pub async fn provide_batch(batch: Batch) -> [u8; 32] {
 
   let block = publish_tx(&Serai::execute_batch(SignedBatch {
     batch: batch.clone(),
-    signature: pair.sign(&batch.encode()),
+    signature: pair.sign(&batch_message(&batch)),
   }))
   .await;
 

substrate/client/tests/common/validator_sets.rs

@@ -3,18 +3,16 @@ use std::collections::HashMap;
 use zeroize::Zeroizing;
 use rand_core::OsRng;
 
-use scale::Encode;
-
 use sp_core::{Pair, sr25519::Signature};
 
 use ciphersuite::{group::GroupEncoding, Ciphersuite, Ristretto};
-use frost::dkg::musig::*;
+use frost::dkg::musig::musig;
 use schnorrkel::Schnorrkel;
 
 use serai_client::{
   primitives::insecure_pair_from_name,
   validator_sets::{
-    primitives::{ValidatorSet, KeyPair},
+    primitives::{ValidatorSet, KeyPair, musig_context, musig_key, set_keys_message},
     ValidatorSetsEvent,
   },
   Serai,
@@ -31,7 +29,7 @@ pub async fn set_validator_set_keys(set: ValidatorSet, key_pair: KeyPair) -> [u8
   let public_key = <Ristretto as Ciphersuite>::read_G::<&[u8]>(&mut public.0.as_ref()).unwrap();
   assert_eq!(
     serai.get_validator_set_musig_key(set).await.unwrap().unwrap(),
-    musig_key::<Ristretto>(&[public_key]).unwrap().to_bytes()
+    musig_key(set, &[public]).0
   );
 
   let secret_key = <Ristretto as Ciphersuite>::read_F::<&[u8]>(
@@ -39,7 +37,8 @@ pub async fn set_validator_set_keys(set: ValidatorSet, key_pair: KeyPair) -> [u8
   )
   .unwrap();
   assert_eq!(Ristretto::generator() * secret_key, public_key);
-  let threshold_keys = musig::<Ristretto>(&Zeroizing::new(secret_key), &[public_key]).unwrap();
+  let threshold_keys =
+    musig::<Ristretto>(&musig_context(set), &Zeroizing::new(secret_key), &[public_key]).unwrap();
   assert_eq!(
     serai.get_validator_set_musig_key(set).await.unwrap().unwrap(),
     threshold_keys.group_key().to_bytes()
@@ -52,7 +51,7 @@ pub async fn set_validator_set_keys(set: ValidatorSet, key_pair: KeyPair) -> [u8
       Schnorrkel::new(b"substrate"),
       &HashMap::from([(threshold_keys.params().i(), threshold_keys.into())]),
     ),
-    &key_pair.encode(),
+    &set_keys_message(&set, &key_pair),
   );
 
   // Vote in a key pair

substrate/client/tests/validator_sets.rs

@@ -2,13 +2,10 @@ use rand_core::{RngCore, OsRng};
 
 use sp_core::{sr25519::Public, Pair};
 
-use ciphersuite::{group::GroupEncoding, Ciphersuite, Ristretto};
-use frost::dkg::musig::musig_key;
-
 use serai_client::{
   primitives::{NETWORKS, NetworkId, insecure_pair_from_name},
   validator_sets::{
-    primitives::{Session, ValidatorSet},
+    primitives::{Session, ValidatorSet, musig_key},
     ValidatorSetsEvent,
   },
   Serai,
@@ -56,12 +53,7 @@ serai_test!(
     assert_eq!(participants_ref, [(public, set_data.bond)].as_ref());
     assert_eq!(
       serai.get_validator_set_musig_key(set).await.unwrap().unwrap(),
-      musig_key::<Ristretto>(&[<Ristretto as Ciphersuite>::read_G::<&[u8]>(
-        &mut public.0.as_ref()
-      )
-      .unwrap()])
-      .unwrap()
-      .to_bytes()
+      musig_key(set, &[public]).0
     );
 
     let block = set_validator_set_keys(set, key_pair.clone()).await;

substrate/in-instructions/pallet/Cargo.toml

@@ -23,7 +23,7 @@ sp-runtime = { git = "https://github.com/serai-dex/substrate", default-features
 frame-system = { git = "https://github.com/serai-dex/substrate", default-features = false }
 frame-support = { git = "https://github.com/serai-dex/substrate", default-features = false }
 
-serai-primitives = { path = "../..//primitives", default-features = false }
+serai-primitives = { path = "../../primitives", default-features = false }
 in-instructions-primitives = { path = "../primitives", default-features = false }
 
 tokens-pallet = { path = "../../tokens/pallet", default-features = false }

substrate/in-instructions/pallet/src/lib.rs

@@ -9,7 +9,7 @@ use sp_runtime::RuntimeDebug;
 use serai_primitives::{BlockHash, NetworkId};
 
 pub use in_instructions_primitives as primitives;
-use primitives::{InInstruction, InInstructionWithBalance, SignedBatch};
+use primitives::*;
 
 #[derive(Clone, Copy, Encode, RuntimeDebug)]
 #[cfg_attr(feature = "std", derive(scale::Decode, thiserror::Error))]
@@ -141,7 +141,7 @@ pub mod pallet {
         }
       };
 
-      if !key.verify(&batch.batch.encode(), &batch.signature) {
+      if !key.verify(&batch_message(&batch.batch), &batch.signature) {
         Err(InvalidTransaction::BadProof)?;
       }
 

substrate/in-instructions/primitives/Cargo.toml

@@ -22,7 +22,7 @@ sp-application-crypto = { git = "https://github.com/serai-dex/substrate", defaul
 sp-std = { git = "https://github.com/serai-dex/substrate", default-features = false }
 sp-runtime = { git = "https://github.com/serai-dex/substrate", default-features = false }
 
-serai-primitives = { path = "../..//primitives", default-features = false }
+serai-primitives = { path = "../../primitives", default-features = false }
 tokens-primitives = { path = "../../tokens/primitives", default-features = false }
 
 [features]

substrate/in-instructions/primitives/src/lib.rs

@@ -79,3 +79,8 @@ impl Zeroize for SignedBatch {
     self.signature.as_mut().zeroize();
   }
 }
+
+/// The message for the batch signature.
+pub fn batch_message(batch: &Batch) -> Vec<u8> {
+  [b"InInstructions-batch".as_ref(), &batch.encode()].concat()
+}

substrate/tokens/pallet/Cargo.toml

@@ -20,7 +20,7 @@ frame-support = { git = "https://github.com/serai-dex/substrate", default-featur
 
 pallet-assets = { git = "https://github.com/serai-dex/substrate", default-features = false }
 
-serai-primitives = { path = "../..//primitives", default-features = false }
+serai-primitives = { path = "../../primitives", default-features = false }
 tokens-primitives = { path = "../primitives", default-features = false }
 
 [features]

substrate/tokens/primitives/Cargo.toml

@@ -18,7 +18,7 @@ scale-info = { version = "2", default-features = false, features = ["derive"] }
 
 serde = { version = "1", features = ["derive"], optional = true }
 
-serai-primitives = { path = "../..//primitives", default-features = false }
+serai-primitives = { path = "../../primitives", default-features = false }
 
 [dev-dependencies]
 sp-runtime = { git = "https://github.com/serai-dex/substrate", default-features = false }

substrate/validator-sets/pallet/Cargo.toml

@@ -14,9 +14,6 @@ rustdoc-args = ["--cfg", "docsrs"]
 [dependencies]
 hashbrown = { version = "0.13", default-features = false }
 
-ciphersuite = { version = "0.3", path = "../../../crypto/ciphersuite", default-features = false, features = ["ristretto"] }
-dkg = { version = "0.4", path = "../../../crypto/dkg", default-features = false }
-
 scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] }
 scale-info = { version = "2", default-features = false, features = ["derive"] }
 
@@ -31,12 +28,12 @@ validator-sets-primitives = { path = "../primitives", default-features = false }
 
 [features]
 std = [
-  "ciphersuite/std",
-  "dkg/std",
-
   "scale/std",
   "scale-info/std",
 
+  "sp-core/std",
+  "sp-application-crypto/std",
+
   "frame-system/std",
   "frame-support/std",
 

substrate/validator-sets/pallet/src/lib.rs

@@ -69,23 +69,14 @@ pub mod pallet {
   #[pallet::genesis_build]
   impl<T: Config> GenesisBuild<T> for GenesisConfig<T> {
     fn build(&self) {
-      use ciphersuite::{group::GroupEncoding, Ciphersuite, Ristretto};
-
-      let hash_set = self.participants.iter().map(|key| key.0).collect::<hashbrown::HashSet<[u8; 32]>>();
-      if hash_set.len() != self.participants.len()
-      {
+      let hash_set =
+        self.participants.iter().map(|key| key.0).collect::<hashbrown::HashSet<[u8; 32]>>();
+      if hash_set.len() != self.participants.len() {
         panic!("participants contained duplicates");
       }
 
       let mut participants = Vec::new();
-      let mut keys = Vec::new();
       for participant in self.participants.clone() {
-        keys.push(
-          <Ristretto as Ciphersuite>::read_G::<&[u8]>(
-            &mut participant.0.as_ref(),
-          )
-          .expect("invalid participant"),
-        );
         participants.push((participant, self.bond));
       }
       let participants = BoundedVec::try_from(participants).unwrap();
@@ -99,7 +90,7 @@ pub mod pallet {
           Some(ValidatorSetData { bond: self.bond, network, participants: participants.clone() }),
         );
 
-        MuSigKeys::<T>::set(set, Some(Public(dkg::musig::musig_key::<Ristretto>(&keys).unwrap().to_bytes())));
+        MuSigKeys::<T>::set(set, Some(musig_key(set, &self.participants)));
         Pallet::<T>::deposit_event(Event::NewSet { set })
       }
     }
@@ -128,7 +119,7 @@ pub mod pallet {
       let Some(musig_key) = MuSigKeys::<T>::get(set) else {
         Err(Error::NonExistentValidatorSet)?
       };
-      if !musig_key.verify(&key_pair.encode(), signature) {
+      if !musig_key.verify(&set_keys_message(&set, key_pair), signature) {
         Err(Error::BadSignature)?;
       }
 
@@ -179,7 +170,9 @@ pub mod pallet {
       let set = ValidatorSet { session, network: *network };
       match Self::verify_signature(set, key_pair, signature) {
         Err(Error::AlreadyGeneratedKeys) => Err(InvalidTransaction::Stale)?,
-        Err(Error::NonExistentValidatorSet) | Err(Error::BadSignature) => Err(InvalidTransaction::BadProof)?,
+        Err(Error::NonExistentValidatorSet) | Err(Error::BadSignature) => {
+          Err(InvalidTransaction::BadProof)?
+        }
         Err(Error::__Ignore(_, _)) => unreachable!(),
         Ok(()) => (),
       }

substrate/validator-sets/primitives/Cargo.toml

@@ -14,15 +14,19 @@ rustdoc-args = ["--cfg", "docsrs"]
 [dependencies]
 zeroize = { version = "^1.5", features = ["derive"], optional = true }
 
+serde = { version = "1", features = ["derive"], optional = true }
+
+ciphersuite = { path = "../../../crypto/ciphersuite", version = "0.3", default-features = false, features = ["alloc", "ristretto"] }
+dkg = { path = "../../../crypto/dkg", version = "0.4", default-features = false }
+
 scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive", "max-encoded-len"] }
 scale-info = { version = "2", default-features = false, features = ["derive"] }
 
-serde = { version = "1", features = ["derive"], optional = true }
-
 sp-core = { git = "https://github.com/serai-dex/substrate", default-features = false }
+sp-std = { git = "https://github.com/serai-dex/substrate", default-features = false }
 
-serai-primitives = { path = "../..//primitives", default-features = false }
+serai-primitives = { path = "../../primitives", default-features = false }
 
 [features]
-std = ["zeroize", "scale/std", "scale-info/std", "serde", "sp-core/std", "serai-primitives/std"]
+std = ["zeroize", "serde", "ciphersuite/std", "dkg/std", "scale/std", "scale-info/std", "sp-core/std", "sp-std/std", "serai-primitives/std"]
 default = ["std"]

substrate/validator-sets/primitives/src/lib.rs

@@ -3,13 +3,17 @@
 #[cfg(feature = "std")]
 use zeroize::Zeroize;
 
-use scale::{Encode, Decode, MaxEncodedLen};
-use scale_info::TypeInfo;
-
 #[cfg(feature = "std")]
 use serde::{Serialize, Deserialize};
 
-use sp_core::{ConstU32, sr25519, bounded::BoundedVec};
+use ciphersuite::{group::GroupEncoding, Ciphersuite, Ristretto};
+
+use scale::{Encode, Decode, MaxEncodedLen};
+use scale_info::TypeInfo;
+
+use sp_core::{ConstU32, sr25519::Public, bounded::BoundedVec};
+#[cfg(not(feature = "std"))]
+use sp_std::vec::Vec;
 
 use serai_primitives::{NetworkId, Network, Amount};
 
@@ -37,13 +41,38 @@ pub struct ValidatorSetData {
 
   // Participant and their amount bonded to this set
   // Limit each set to 100 participants for now
-  pub participants: BoundedVec<(sr25519::Public, Amount), ConstU32<100>>,
+  pub participants: BoundedVec<(Public, Amount), ConstU32<100>>,
 }
 
 type MaxKeyLen = ConstU32<MAX_KEY_LEN>;
 /// The type representing a Key from an external network.
 pub type ExternalKey = BoundedVec<u8, MaxKeyLen>;
 
-/// A Validator Set's Ristretto key, used for signing InInstructions, and their key on the external
-/// network.
-pub type KeyPair = (sr25519::Public, ExternalKey);
+/// The key pair for a validator set.
+///
+/// This is their Ristretto key, used for signing Batches, and their key on the external network.
+pub type KeyPair = (Public, ExternalKey);
+
+/// The MuSig context for a validator set.
+pub fn musig_context(set: ValidatorSet) -> Vec<u8> {
+  [b"ValidatorSets-musig_key".as_ref(), &set.encode()].concat()
+}
+
+/// The MuSig public key for a validator set.
+///
+/// This function panics on invalid input.
+pub fn musig_key(set: ValidatorSet, set_keys: &[Public]) -> Public {
+  let mut keys = Vec::new();
+  for key in set_keys {
+    keys.push(
+      <Ristretto as Ciphersuite>::read_G::<&[u8]>(&mut key.0.as_ref())
+        .expect("invalid participant"),
+    );
+  }
+  Public(dkg::musig::musig_key::<Ristretto>(&musig_context(set), &keys).unwrap().to_bytes())
+}
+
+/// The message for the set_keys signature.
+pub fn set_keys_message(set: &ValidatorSet, key_pair: &KeyPair) -> Vec<u8> {
+  [b"ValidatorSets-key_pair".as_ref(), &(set, key_pair).encode()].concat()
+}