From 21ff3e33ff7c6c768d178544108172f6b76c39fb Mon Sep 17 00:00:00 2001
From: Timofey Luin <timofey.luin@gmail.com>
Date: Mon, 25 Sep 2023 19:40:22 +0200
Subject: [PATCH] fix attested state source

---
 lightclient-circuits/src/witness/sync.rs | 5 -----
 preprocessor/src/sync.rs                 | 8 ++++++--
 2 files changed, 6 insertions(+), 7 deletions(-)

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,
     };