add initial IL gossip verification

beacon_node/beacon_chain/src/inclusion_list_verification.rs

@@ -0,0 +1,104 @@
+use crate::{BeaconChain, BeaconChainError, BeaconChainTypes};
+
+use slot_clock::SlotClock;
+use strum::AsRefStr;
+use types::{Domain, EthSpec, SignedInclusionList, SignedRoot, Slot};
+
+#[derive(Debug, AsRefStr)]
+pub enum GossipInclusionListError {
+    FutureSlot {
+        message_slot: Slot,
+        latest_permissible_slot: Slot,
+    },
+    PastSlot {
+        message_slot: Slot,
+        earliest_permissible_slot: Slot,
+    },
+    InvalidCommitteeRoot,
+    ValidatorNotInCommittee,
+    TooManyTransactions,
+    InvalidSignature,
+    BeaconChainError(BeaconChainError),
+    // TODO: equivocation e.g. PriorInclusionListKnown
+}
+
+impl From<BeaconChainError> for GossipInclusionListError {
+    fn from(value: BeaconChainError) -> Self {
+        Self::BeaconChainError(value)
+    }
+}
+
+pub struct GossipVerifiedInclusionList<T: BeaconChainTypes> {
+    signed_il: SignedInclusionList<T::EthSpec>,
+}
+
+impl<T: BeaconChainTypes> GossipVerifiedInclusionList<T> {
+    pub fn verify(
+        signed_il: &SignedInclusionList<T::EthSpec>,
+        chain: &BeaconChain<T>,
+    ) -> Result<Self, GossipInclusionListError> {
+        // the slot is equal to the previous slot or the current slot
+        let message_slot = signed_il.message.slot;
+        let earliest_permissible_slot = chain
+            .slot_clock
+            .now_with_past_tolerance(chain.spec.maximum_gossip_clock_disparity())
+            .ok_or(BeaconChainError::UnableToReadSlot)?;
+        if message_slot < earliest_permissible_slot {
+            return Err(GossipInclusionListError::PastSlot {
+                message_slot,
+                earliest_permissible_slot,
+            });
+        }
+        let latest_permissible_slot = chain
+            .slot_clock
+            .now_with_future_tolerance(chain.spec.maximum_gossip_clock_disparity())
+            .ok_or(BeaconChainError::UnableToReadSlot)?;
+        if message_slot > latest_permissible_slot {
+            return Err(GossipInclusionListError::FutureSlot {
+                message_slot,
+                latest_permissible_slot,
+            });
+        }
+
+        // TODO: the slot is equal to the current slot or the previous slot and the current time is
+        // not past the attestation deadline
+
+        // TODO: the IL committee root is equal to the hash tree root of the expected committee
+
+        // TODO: the validator index is contained in the committee corresponding to the committee
+        // root
+
+        // the transaction length is less than or equal to the specified maximum
+        if signed_il.message.transactions.len() > T::EthSpec::max_transactions_per_inclusion_list()
+        {
+            return Err(GossipInclusionListError::TooManyTransactions);
+        }
+
+        // TODO: the message is the first or second valid message received from the validator
+        // corresponding to the validator index
+
+        // the signature is valid w.r.t. the validator index
+        let epoch = chain.epoch()?;
+        let fork = chain.spec.fork_at_epoch(epoch);
+        let genesis_validators_root = chain.genesis_validators_root;
+        let domain = chain.spec.get_domain(
+            epoch,
+            Domain::InclusionListCommittee,
+            &fork,
+            genesis_validators_root,
+        );
+        let message = signed_il.message.signing_root(domain);
+        let validator_index = signed_il.message.validator_index as usize;
+        let pubkey = chain.validator_pubkey(validator_index)?;
+        let Some(pubkey) = pubkey else {
+            return Err(GossipInclusionListError::BeaconChainError(
+                BeaconChainError::ValidatorIndexUnknown(validator_index),
+            ));
+        };
+        signed_il.signature.verify(&pubkey, message);
+
+        Ok(Self {
+            signed_il: signed_il.clone(),
+        })
+    }
+}

beacon_node/beacon_chain/src/lib.rs

@@ -34,6 +34,7 @@ pub mod fork_revert;
 pub mod graffiti_calculator;
 mod head_tracker;
 pub mod historical_blocks;
+pub mod inclusion_list_verification;
 pub mod kzg_utils;
 pub mod light_client_finality_update_verification;
 pub mod light_client_optimistic_update_verification;