feat(eth-lc): handle electra fork

Author: hussein-aitlahcen

lib/beacon-api-types/src/lib.rs

@@ -63,7 +63,7 @@ use std::{
 
 use hex_literal::hex;
 use typenum::{NonZero, Unsigned};
-use unionlabs::primitives::FixedBytes;
+use unionlabs::primitives::{FixedBytes, H256};
 
 pub use crate::{
     attestation::Attestation, attestation_data::AttestationData,
@@ -368,6 +368,10 @@ consts_traits![
 mk_chain_spec!(Minimal is preset::MINIMAL);
 mk_chain_spec!(Mainnet is preset::MAINNET);
 
+pub type CurrentSyncCommitteeBranch = Vec<H256>;
+pub type NextSyncCommitteeBranch = Vec<H256>;
+pub type FinalityBranch = Vec<H256>;
+
 /// Values that are constant across all configurations.
 pub mod consts {
     use hex_literal::hex;
@@ -394,13 +398,13 @@ pub mod consts {
 
     // https://github.com/ethereum/consensus-specs/blob/dev/ssz/merkle-proofs.md
     /// `get_generalized_index(BeaconState, "finalized_checkpoint", "root")`
-    pub const FINALIZED_ROOT_INDEX: u64 = 105;
+    pub const FINALIZED_ROOT_GINDEX: u64 = 105;
     /// `get_generalized_index(BeaconState, "current_sync_committee")`
-    pub const CURRENT_SYNC_COMMITTEE_INDEX: u64 = 54;
+    pub const CURRENT_SYNC_COMMITTEE_GINDEX: u64 = 54;
     /// `get_generalized_index(BeaconState, "next_sync_committee")`
-    pub const NEXT_SYNC_COMMITTEE_INDEX: u64 = 55;
+    pub const NEXT_SYNC_COMMITTEE_GINDEX: u64 = 55;
     /// `get_generalized_index(BeaconBlockBody, "execution_payload")`
-    pub const EXECUTION_PAYLOAD_INDEX: u64 = 25;
+    pub const EXECUTION_PAYLOAD_GINDEX: u64 = 25;
 
     pub const fn default_epoch() -> u64 {
         u64::MAX

lib/beacon-api-types/src/light_client_bootstrap.rs

@@ -1,9 +1,7 @@
-use unionlabs::primitives::H256;
-
 use crate::{
-    consts::{floorlog2, CURRENT_SYNC_COMMITTEE_INDEX},
     light_client_header::LightClientHeader,
     sync_committee::SyncCommittee,
+    CurrentSyncCommitteeBranch,
 };
 
 #[derive(Debug, Clone, PartialEq)]
@@ -12,5 +10,5 @@ pub struct LightClientBootstrap {
     pub header: LightClientHeader,
     /// Current sync committee corresponding to `beacon_header.state_root`
     pub current_sync_committee: SyncCommittee,
-    pub current_sync_committee_branch: [H256; floorlog2(CURRENT_SYNC_COMMITTEE_INDEX)],
+    pub current_sync_committee_branch: CurrentSyncCommitteeBranch,
 }

lib/beacon-api-types/src/light_client_finality_update.rs

@@ -1,10 +1,4 @@
-use unionlabs::primitives::H256;
-
-use crate::{
-    consts::{floorlog2, FINALIZED_ROOT_INDEX},
-    light_client_header::LightClientHeader,
-    Slot, SyncAggregate,
-};
+use crate::{light_client_header::LightClientHeader, FinalityBranch, Slot, SyncAggregate};
 
 #[derive(Debug, Clone, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
@@ -13,7 +7,7 @@ pub struct LightClientFinalityUpdate {
     pub attested_header: LightClientHeader,
     /// Finalized header corresponding to `attested_header.state_root`
     pub finalized_header: LightClientHeader,
-    pub finality_branch: [H256; floorlog2(FINALIZED_ROOT_INDEX)],
+    pub finality_branch: FinalityBranch,
     /// Sync committee aggregate signature
     pub sync_aggregate: SyncAggregate,
     /// Slot at which the aggregate signature was created (untrusted)

lib/beacon-api-types/src/light_client_header.rs

@@ -2,7 +2,7 @@ use unionlabs::primitives::H256;
 
 use crate::{
     beacon_block_header::BeaconBlockHeader,
-    consts::{floorlog2, EXECUTION_PAYLOAD_INDEX},
+    consts::{floorlog2, EXECUTION_PAYLOAD_GINDEX},
     execution_payload_header::ExecutionPayloadHeader,
 };
 
@@ -12,7 +12,7 @@ use crate::{
 pub struct LightClientHeader {
     pub beacon: BeaconBlockHeader,
     pub execution: ExecutionPayloadHeader,
-    pub execution_branch: [H256; floorlog2(EXECUTION_PAYLOAD_INDEX)],
+    pub execution_branch: [H256; floorlog2(EXECUTION_PAYLOAD_GINDEX)],
 }
 
 #[cfg(feature = "ssz")]
@@ -25,5 +25,5 @@ pub struct LightClientHeader {
 pub struct LightClientHeaderSsz<C: crate::BYTES_PER_LOGS_BLOOM + crate::MAX_EXTRA_DATA_BYTES> {
     pub beacon: BeaconBlockHeader,
     pub execution: crate::ExecutionPayloadHeaderSsz<C>,
-    pub execution_branch: [H256; floorlog2(EXECUTION_PAYLOAD_INDEX)],
+    pub execution_branch: [H256; floorlog2(EXECUTION_PAYLOAD_GINDEX)],
 }

lib/beacon-api-types/src/light_client_update.rs

@@ -1,13 +1,7 @@
-use unionlabs::primitives::H256;
-
 use crate::{
-    consts::{floorlog2, FINALIZED_ROOT_INDEX, NEXT_SYNC_COMMITTEE_INDEX},
-    LightClientHeader, Slot, SyncAggregate, SyncCommittee,
+    FinalityBranch, LightClientHeader, NextSyncCommitteeBranch, Slot, SyncAggregate, SyncCommittee,
 };
 
-pub type NextSyncCommitteeBranch = [H256; floorlog2(NEXT_SYNC_COMMITTEE_INDEX)];
-pub type FinalityBranch = [H256; floorlog2(FINALIZED_ROOT_INDEX)];
-
 #[derive(Debug, Clone, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct LightClientUpdate {

lib/ethereum-light-client-types/src/light_client_update.rs

@@ -1,4 +1,4 @@
-use beacon_api_types::{light_client_update::NextSyncCommitteeBranch, SyncCommittee};
+use beacon_api_types::{NextSyncCommitteeBranch, SyncCommittee};
 
 use crate::LightClientUpdateData;
 

lib/ethereum-light-client-types/src/light_client_update_data.rs

@@ -1,6 +1,5 @@
 use beacon_api_types::{
-    light_client_update::{FinalityBranch, NextSyncCommitteeBranch},
-    LightClientHeader, Slot, SyncAggregate, SyncCommittee,
+    FinalityBranch, LightClientHeader, NextSyncCommitteeBranch, Slot, SyncAggregate, SyncCommittee
 };
 
 /// Common data required for all light client updates.

lib/ethereum-sync-protocol/src/lib.rs

@@ -7,8 +7,9 @@ pub mod utils;
 
 use beacon_api_types::{
     consts::{
-        floorlog2, get_subtree_index, EXECUTION_PAYLOAD_INDEX, FINALIZED_ROOT_INDEX,
-        NEXT_SYNC_COMMITTEE_INDEX,
+        CURRENT_SYNC_COMMITTEE_GINDEX, CURRENT_SYNC_COMMITTEE_GINDEX_ELECTRA,
+        EXECUTION_PAYLOAD_GINDEX, FINALIZED_ROOT_GINDEX, FINALIZED_ROOT_GINDEX_ELECTRA,
+        NEXT_SYNC_COMMITTEE_GINDEX, NEXT_SYNC_COMMITTEE_GINDEX_ELECTRA,
     },
     light_client_update::LightClientUpdate,
     ChainSpec, DomainType, ExecutionPayloadHeaderSsz, ForkParameters, LightClientHeader, Slot,
@@ -42,6 +43,42 @@ pub trait BlsVerify {
     ) -> Result<(), Error>;
 }
 
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#finalized_root_gindex_at_slot
+pub fn finalized_root_gindex_at_slot<C: ChainSpec>(
+    fork_parameters: &ForkParameters,
+    slot: Slot,
+) -> u64 {
+    let epoch = compute_epoch_at_slot::<C>(slot);
+    if epoch >= fork_parameters.electra.epoch {
+        return FINALIZED_ROOT_GINDEX_ELECTRA;
+    }
+    FINALIZED_ROOT_GINDEX
+}
+
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#current_sync_committee_gindex_at_slot
+pub fn current_sync_committee_gindex_at_slot<C: ChainSpec>(
+    fork_parameters: &ForkParameters,
+    slot: Slot,
+) -> u64 {
+    let epoch = compute_epoch_at_slot::<C>(slot);
+    if epoch >= fork_parameters.electra.epoch {
+        return CURRENT_SYNC_COMMITTEE_GINDEX_ELECTRA;
+    }
+    CURRENT_SYNC_COMMITTEE_GINDEX
+}
+
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/light-client/sync-protocol.md#next_sync_committee_gindex_at_slot
+pub fn next_sync_committee_gindex_at_slot<C: ChainSpec>(
+    fork_parameters: &ForkParameters,
+    slot: Slot,
+) -> u64 {
+    let epoch = compute_epoch_at_slot::<C>(slot);
+    if epoch >= fork_parameters.electra.epoch {
+        return NEXT_SYNC_COMMITTEE_GINDEX_ELECTRA;
+    }
+    NEXT_SYNC_COMMITTEE_GINDEX
+}
+
 /// Verifies if the light client `update` is valid.
 ///
 /// * `update`: The light client update we want to verify.
@@ -169,8 +206,7 @@ pub fn validate_light_client_update<C: ChainSpec, V: BlsVerify>(
     validate_merkle_branch(
         &update.finalized_header.beacon.tree_hash_root(),
         &update.finality_branch,
-        floorlog2(FINALIZED_ROOT_INDEX),
-        get_subtree_index(FINALIZED_ROOT_INDEX),
+        finalized_root_gindex_at_slot::<C>(fork_parameters, update_attested_slot),
         &update.attested_header.beacon.state_root,
     )?;
 
@@ -188,14 +224,17 @@ pub fn validate_light_client_update<C: ChainSpec, V: BlsVerify>(
                 },
             )?;
         }
+
         // This validates the given next sync committee against the attested header's state root.
         validate_merkle_branch(
             &TryInto::<SyncCommitteeSsz<C>>::try_into(next_sync_committee.clone())
                 .unwrap()
                 .tree_hash_root(),
-            &update.next_sync_committee_branch.unwrap_or_default(),
-            floorlog2(NEXT_SYNC_COMMITTEE_INDEX),
-            get_subtree_index(NEXT_SYNC_COMMITTEE_INDEX),
+            &update
+                .next_sync_committee_branch
+                .clone()
+                .unwrap_or_default()[..],
+            next_sync_committee_gindex_at_slot::<C>(fork_parameters, update_attested_slot),
             &update.attested_header.beacon.state_root,
         )?;
     }
@@ -245,19 +284,17 @@ pub fn get_lc_execution_root<C: ChainSpec>(
     header: &LightClientHeader,
 ) -> H256 {
     let epoch = compute_epoch_at_slot::<C>(header.beacon.slot);
+    // Now new field in electra
+    if epoch >= fork_parameters.electra.epoch {
+        return TryInto::<ExecutionPayloadHeaderSsz<C>>::try_into(header.execution.clone())
+            .unwrap()
+            .tree_hash_root();
+    }
     if epoch >= fork_parameters.deneb.epoch {
         return TryInto::<ExecutionPayloadHeaderSsz<C>>::try_into(header.execution.clone())
             .unwrap()
             .tree_hash_root();
     }
-
-    // TODO: Figure out what to do here
-    // if epoch >= fork_parameters.capella.epoch {
-    //     return CapellaExecutionPayloadHeader::from(header.execution.clone())
-    //         .tree_hash_root()
-    //         .into();
-    // }
-
     H256::default()
 }
 
@@ -285,8 +322,7 @@ pub fn is_valid_light_client_header<C: ChainSpec>(
     validate_merkle_branch(
         &get_lc_execution_root::<C>(fork_parameters, header),
         &header.execution_branch,
-        floorlog2(EXECUTION_PAYLOAD_INDEX),
-        get_subtree_index(EXECUTION_PAYLOAD_INDEX),
+        EXECUTION_PAYLOAD_GINDEX,
         &header.beacon.body_root,
     )
 }

lib/ethereum-sync-protocol/src/utils.rs

@@ -1,4 +1,5 @@
 use beacon_api_types::{
+    consts::{floorlog2, get_subtree_index},
     Domain, DomainType, ForkData, ForkParameters, SigningData, Slot, Version,
     EPOCHS_PER_SYNC_COMMITTEE_PERIOD, SECONDS_PER_SLOT, SLOTS_PER_EPOCH,
 };
@@ -139,12 +140,12 @@ pub fn validate_signature_supermajority(sync_committee_bits: &[u8]) -> bool {
 pub fn validate_merkle_branch<'a>(
     leaf: &H256,
     branch: impl IntoIterator<Item = &'a H256>,
-    depth: usize,
-    index: u64,
+    gindex: u64,
     root: &H256,
 ) -> Result<(), Error> {
+    let depth = floorlog2(gindex);
+    let index = get_subtree_index(gindex);
     let branch = branch.into_iter().cloned().collect::<Vec<_>>();
-
     'block: {
         let mut value = *leaf;
 
@@ -340,8 +341,8 @@ pub fn validate_merkle_branch<'a>(
 //     //         validate_merkle_branch(
 //     //             &valid_leaf,
 //     //             &valid_branch,
-//     //             floorlog2(EXECUTION_PAYLOAD_INDEX),
-//     //             EXECUTION_PAYLOAD_INDEX,
+//     //             floorlog2(EXECUTION_PAYLOAD_GINDEX),
+//     //             EXECUTION_PAYLOAD_GINDEX,
 //     //             &valid_root,
 //     //         ),
 //     //         Ok(())
@@ -351,8 +352,8 @@ pub fn validate_merkle_branch<'a>(
 //     //     assert!(validate_merkle_branch(
 //     //         &valid_leaf,
 //     //         &valid_branch,
-//     //         floorlog2(EXECUTION_PAYLOAD_INDEX),
-//     //         EXECUTION_PAYLOAD_INDEX + 1,
+//     //         floorlog2(EXECUTION_PAYLOAD_GINDEX),
+//     //         EXECUTION_PAYLOAD_GINDEX + 1,
 //     //         &valid_root,
 //     //     )
 //     //     .is_err());
@@ -367,8 +368,8 @@ pub fn validate_merkle_branch<'a>(
 //     //     assert!(validate_merkle_branch(
 //     //         &invalid_leaf,
 //     //         &valid_branch,
-//     //         floorlog2(EXECUTION_PAYLOAD_INDEX),
-//     //         EXECUTION_PAYLOAD_INDEX,
+//     //         floorlog2(EXECUTION_PAYLOAD_GINDEX),
+//     //         EXECUTION_PAYLOAD_GINDEX,
 //     //         &valid_root,
 //     //     )
 //     //     .is_err());
@@ -383,8 +384,8 @@ pub fn validate_merkle_branch<'a>(
 //     //     assert!(validate_merkle_branch(
 //     //         &valid_leaf,
 //     //         &invalid_branch,
-//     //         floorlog2(EXECUTION_PAYLOAD_INDEX),
-//     //         EXECUTION_PAYLOAD_INDEX,
+//     //         floorlog2(EXECUTION_PAYLOAD_GINDEX),
+//     //         EXECUTION_PAYLOAD_GINDEX,
 //     //         &valid_root,
 //     //     )
 //     //     .is_err());