From 4456af3eb777c556260d4c73e5bf32915b0e2f47 Mon Sep 17 00:00:00 2001
From: timofey <timofey.luin@gmail.com>
Date: Mon, 25 Sep 2023 19:53:16 +0200
Subject: [PATCH] Fix attested state root source  (#15)

* fix: swap finalized and attested header stateroot

* fix attested state source

---------

Co-authored-by: ec2 <tu.eric@hotmail.com>
---
 lightclient-circuits/src/sync_step_circuit.rs | 18 +++++++++---------
 lightclient-circuits/src/witness/sync.rs      |  5 -----
 preprocessor/src/sync.rs                      |  8 ++++++--
 3 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/lightclient-circuits/src/sync_step_circuit.rs b/lightclient-circuits/src/sync_step_circuit.rs
index 587c8c58..97f74eab 100644
--- a/lightclient-circuits/src/sync_step_circuit.rs
+++ b/lightclient-circuits/src/sync_step_circuit.rs
@@ -130,6 +130,13 @@ impl<S: Spec, F: Field> SyncStepCircuit<S, F> {
 
         // Verify attestted header
         let attested_slot: HashInputChunk<_> = args.attested_header.slot.into_witness();
+        let attested_header_state_root = args
+            .attested_header
+            .state_root
+            .as_ref()
+            .iter()
+            .map(|v| thread_pool.main().load_witness(F::from(*v as u64)))
+            .collect_vec();
         let attested_header = ssz_merkleize_chunks(
             thread_pool,
             &sha256_chip,
@@ -137,7 +144,7 @@ impl<S: Spec, F: Field> SyncStepCircuit<S, F> {
                 attested_slot.clone(),
                 args.attested_header.proposer_index.into_witness(),
                 args.attested_header.parent_root.as_ref().into_witness(),
-                args.attested_header.state_root.as_ref().into_witness(),
+                attested_header_state_root.clone().into(),
                 args.attested_header.body_root.as_ref().into_witness(),
             ],
         )?;
@@ -155,13 +162,6 @@ impl<S: Spec, F: Field> SyncStepCircuit<S, F> {
             .collect_vec();
 
         let finalized_slot: HashInputChunk<_> = args.finalized_header.slot.into_witness();
-        let attested_header_state_root = args
-            .attested_header
-            .state_root
-            .as_ref()
-            .iter()
-            .map(|v| thread_pool.main().load_witness(F::from(*v as u64)))
-            .collect_vec();
 
         let finalized_header_root = ssz_merkleize_chunks(
             thread_pool,
@@ -170,7 +170,7 @@ impl<S: Spec, F: Field> SyncStepCircuit<S, F> {
                 finalized_slot.clone(),
                 args.finalized_header.proposer_index.into_witness(),
                 args.finalized_header.parent_root.as_ref().into_witness(),
-                attested_header_state_root.clone().into(),
+                args.finalized_header.state_root.as_ref().into_witness(),
                 finalized_block_body_root.clone().into(),
             ],
         )?;
diff --git a/lightclient-circuits/src/witness/sync.rs b/lightclient-circuits/src/witness/sync.rs
index e855daa4..918adc01 100644
--- a/lightclient-circuits/src/witness/sync.rs
+++ b/lightclient-circuits/src/witness/sync.rs
@@ -29,8 +29,6 @@ pub struct SyncStepArgs<S: Spec> {
 
     pub finality_branch: Vec<Vec<u8>>,
 
-    pub beacon_state_root: Vec<u8>,
-
     #[serde(skip)]
     pub _spec: PhantomData<S>,
 }
@@ -66,8 +64,6 @@ impl<S: Spec> Default for SyncStepArgs<S> {
 
         let finality_merkle_branch = vec![vec![0; 32]; S::FINALIZED_HEADER_DEPTH];
 
-        let beacon_state_root = compute_root(finalized_header, &state_merkle_branch);
-
         Self {
             signature_compressed: hex::decode("462c5acb68722355eaa568a166e6da4c46702a496586aa94c681e0b03a200394b8f4adc98d6b5a68e3caf9dae31ff7035a402aad93bdd4752e521b3b536b47dee55d129b6374177f2be8c99b6ea6618abae84b389affc5a50ad8d991f763beaa").unwrap(),
             pubkeys_uncompressed: iter::repeat(dummy_pk_bytes)
@@ -81,7 +77,6 @@ impl<S: Spec> Default for SyncStepArgs<S> {
             attested_header: BeaconBlockHeader::default(),
             finalized_header: finalized_block,
             finality_branch: finality_merkle_branch,
-            beacon_state_root,
             execution_payload_branch: execution_merkle_branch,
             execution_payload_root: execution_state_root,
             _spec: PhantomData,
diff --git a/preprocessor/src/sync.rs b/preprocessor/src/sync.rs
index aea3f3d6..1c98c36f 100644
--- a/preprocessor/src/sync.rs
+++ b/preprocessor/src/sync.rs
@@ -15,7 +15,7 @@ use tokio::fs;
 pub async fn fetch_step_args<S: Spec>(node_url: String) -> eyre::Result<SyncStepArgs<S>> {
     let client = SyncCommitteeProver::new(node_url);
     let state_id = "head";
-    let mut state = client
+    let state = client
         .fetch_beacon_state(state_id)
         .await
         .map_err(|e| eyre::eyre!("Error fetching state from node. Error: {}", e))?;
@@ -47,6 +47,11 @@ pub async fn fetch_step_args<S: Spec>(node_url: String) -> eyre::Result<SyncStep
         .map_err(|e| eyre::eyre!("Error fetching light client update. Error: {}", e))?
         .expect("Light client update should be present");
 
+    let mut state = client
+        .fetch_beacon_state(&light_client_update.attested_header.slot.to_string())
+        .await
+        .map_err(|e| eyre::eyre!("Error fetching state from node. Error: {}", e))?;
+
     let pubkeys_uncompressed = client_state
         .current_sync_committee
         .public_keys
@@ -157,7 +162,6 @@ pub async fn fetch_step_args<S: Spec>(node_url: String) -> eyre::Result<SyncStep
             .iter()
             .map(|n| n.as_bytes().to_vec())
             .collect_vec(),
-        beacon_state_root: state_root.as_bytes().to_vec(),
         _spec: PhantomData,
     };