refactor into multiple modules

src/consensus_client.rs

@@ -0,0 +1,149 @@
+use eyre::Result;
+use ssz_rs::prelude::*;
+use super::utils::*;
+use serde::de::Error;
+
+pub struct ConsensusClient {
+    rpc: String,
+}
+
+impl ConsensusClient {
+    pub fn new(rpc: &str) -> Self {
+        ConsensusClient { rpc: rpc.to_string() }
+    }
+
+    pub async fn get_bootstrap(&self, block_root: &str) -> Result<Bootstrap> {
+        let req = format!("{}/eth/v0/beacon/light_client/bootstrap/{}", self.rpc, block_root);
+        let res = reqwest::get(req).await?.json::<BootstrapResponse>().await?;
+        Ok(res.data.v)
+    }
+
+    pub async fn get_updates(&self, period: u64) -> Result<Vec<Update>> {
+        let req = format!("{}/eth/v0/beacon/light_client/updates?start_period={}&count=1000", self.rpc, period);
+        let res = reqwest::get(req).await?.json::<UpdateResponse>().await?;
+        Ok(res.data)
+    }
+
+    pub async fn get_finality_update(&self) -> Result<FinalityUpdate> {
+        let req = format!("{}/eth/v0/beacon/light_client/finality_update", self.rpc);
+        let res = reqwest::get(req).await?.json::<FinalityUpdateResponse>().await?;
+        Ok(res.data)
+    }
+}
+
+pub type BLSPubKey = Vector<u8, 48>;
+pub type Bytes32 = Vector<u8, 32>;
+
+#[derive(serde::Deserialize, Debug)]
+pub struct Bootstrap {
+    pub header: Header,
+    pub current_sync_committee: SyncCommittee,
+    #[serde(deserialize_with = "branch_deserialize")]
+    pub current_sync_committee_branch: Vec<Bytes32>,
+}
+
+#[derive(serde::Deserialize, Debug, Clone)]
+pub struct Update {
+    pub attested_header: Header,
+    pub next_sync_committee: Option<SyncCommittee>,
+    #[serde(deserialize_with = "branch_deserialize")]
+    pub next_sync_committee_branch: Vec<Bytes32>,
+    pub finalized_header: Header,
+    #[serde(deserialize_with = "branch_deserialize")]
+    pub finality_branch: Vec<Bytes32>,
+    pub sync_aggregate: SyncAggregate,
+    #[serde(deserialize_with = "u64_deserialize")]
+    pub signature_slot: u64,
+}
+
+#[derive(serde::Deserialize, Debug)]
+pub struct FinalityUpdate {
+    pub attested_header: Header,
+    pub finalized_header: Header,
+    #[serde(deserialize_with = "branch_deserialize")]
+    pub finality_branch: Vec<Bytes32>,
+    pub sync_aggregate: SyncAggregate,
+    #[serde(deserialize_with = "u64_deserialize")]
+    pub signature_slot: u64,
+}
+
+#[derive(serde::Deserialize, Debug, Clone, Default, SimpleSerialize)]
+pub struct Header {
+    #[serde(deserialize_with = "u64_deserialize")]
+    pub slot: u64,
+    #[serde(deserialize_with = "u64_deserialize")]
+    pub proposer_index: u64,
+    #[serde(deserialize_with = "bytes32_deserialize")]
+    pub parent_root: Bytes32,
+    #[serde(deserialize_with = "bytes32_deserialize")]
+    pub state_root: Bytes32,
+    #[serde(deserialize_with = "bytes32_deserialize")]
+    pub body_root: Bytes32,
+}
+
+#[derive(Debug, Clone, Default, SimpleSerialize, serde::Deserialize)]
+pub struct SyncCommittee {
+    #[serde(deserialize_with = "pubkeys_deserialize")]
+    pub pubkeys: Vector<BLSPubKey, 512>,
+    #[serde(deserialize_with = "pubkey_deserialize")]
+    pub aggregate_pubkey: BLSPubKey,
+}
+
+#[derive(serde::Deserialize, Debug, Clone)]
+pub struct SyncAggregate {
+    pub sync_committee_bits: String,
+    pub sync_committee_signature: String,
+}
+
+#[derive(serde::Deserialize, Debug)]
+struct UpdateResponse {
+    data: Vec<Update>,
+}
+
+#[derive(serde::Deserialize, Debug)]
+struct FinalityUpdateResponse {
+    data: FinalityUpdate,
+}
+
+#[derive(serde::Deserialize, Debug)]
+struct BootstrapResponse {
+    data: BootstrapData,
+}
+
+#[derive(serde::Deserialize, Debug)]
+struct BootstrapData {
+    v: Bootstrap,
+}
+
+fn pubkey_deserialize<'de, D>(deserializer: D) -> Result<BLSPubKey, D::Error> where D: serde::Deserializer<'de> {
+    let key: String = serde::Deserialize::deserialize(deserializer)?;
+    let key_bytes = hex_str_to_bytes(&key).map_err(D::Error::custom)?;
+    Ok(Vector::from_iter(key_bytes))
+}
+
+fn pubkeys_deserialize<'de, D>(deserializer: D) -> Result<Vector<BLSPubKey, 512>, D::Error> where D: serde::Deserializer<'de> {
+    let keys: Vec<String> = serde::Deserialize::deserialize(deserializer)?;
+    Ok(keys.iter().map(|key| {
+        let key_bytes = hex_str_to_bytes(key)?;
+        Ok(Vector::from_iter(key_bytes))
+    }).collect::<Result<Vector<BLSPubKey, 512>>>().map_err(D::Error::custom)?)
+}
+
+fn branch_deserialize<'de, D>(deserializer: D) -> Result<Vec<Bytes32>, D::Error> where D: serde::Deserializer<'de> {
+    let branch: Vec<String> = serde::Deserialize::deserialize(deserializer)?;
+    Ok(branch.iter().map(|elem| {
+        let elem_bytes = hex_str_to_bytes(elem)?;
+        Ok(Vector::from_iter(elem_bytes))
+    }).collect::<Result<_>>().map_err(D::Error::custom)?)
+}
+
+fn u64_deserialize<'de, D>(deserializer: D) -> Result<u64, D::Error> where D: serde::Deserializer<'de> {
+    let val: String = serde::Deserialize::deserialize(deserializer)?;
+    Ok(val.parse().unwrap())
+}
+
+fn bytes32_deserialize<'de, D>(deserializer: D) -> Result<Bytes32, D::Error> where D: serde::Deserializer<'de> {
+    let bytes: String = serde::Deserialize::deserialize(deserializer)?;
+    let bytes = hex::decode(bytes.strip_prefix("0x").unwrap()).unwrap();
+    Ok(bytes.to_vec().try_into().unwrap())
+}

src/main.rs

@@ -1,6 +1,11 @@
 use eyre::Result;
 use ssz_rs::prelude::*;
 use blst::{min_pk::*, BLST_ERROR};
+use consensus_client::*;
+use utils::*;
+
+pub mod consensus_client;
+pub mod utils;
 
 #[tokio::main]
 async fn main() -> Result<()> {
@@ -16,7 +21,7 @@ async fn main() -> Result<()> {
 }
 
 struct LightClient {
-    nimbus_rpc: String,
+    consensus_client: ConsensusClient,
     store: Store,
 }
 
@@ -30,18 +35,18 @@ struct Store {
 impl LightClient {
     async fn new(nimbus_rpc: &str, checkpoint_block_root: &str) -> Result<LightClient> {
 
-        let mut bootstrap = Self::get_bootstrap(nimbus_rpc, checkpoint_block_root).await?;
+        let consensus_client = ConsensusClient::new(nimbus_rpc);
 
-        let committee_hash = bootstrap.current_sync_committee.hash_tree_root()?;
-        let root = Node::from_bytes(bootstrap.header.state_root);
-        let committee_branch = branch_to_nodes(bootstrap.current_sync_committee_branch);
+        let mut bootstrap = consensus_client.get_bootstrap(checkpoint_block_root).await?;
 
-        let committee_valid = is_valid_merkle_branch(&committee_hash, committee_branch.iter(), 5, 22, &root);
-        println!("bootstrap committee valid: {}", committee_valid);
+        let committee_valid = is_current_committee_proof_valid(
+            &bootstrap.header,
+            &mut bootstrap.current_sync_committee,
+            &bootstrap.current_sync_committee_branch
+        );
 
         let header_hash = bootstrap.header.hash_tree_root()?;
         let header_valid = header_hash.to_string() == checkpoint_block_root.to_string();
-        println!("bootstrap header valid: {}", header_valid);
 
         if !(header_valid && committee_valid) {
             return Err(eyre::eyre!("Invalid Bootstrap"));
@@ -53,23 +58,20 @@ impl LightClient {
             next_sync_committee: None,
         };
 
-        Ok(LightClient { nimbus_rpc: nimbus_rpc.to_string(), store })
+        Ok(LightClient { consensus_client, store })
     }
 
     async fn sync(&mut self) -> Result<()> {
 
         let current_period = calc_sync_period(self.store.header.slot);
-        let next_period = current_period +  0;
-
-        let updates = self.get_updates(next_period).await?;
+        let updates = self.consensus_client.get_updates(current_period).await?;
 
         for mut update in updates {
             self.verify_update(&mut update)?;
             self.apply_update(&update);
-            println!("================================");
         }
 
-        let finality_update = self.get_finality_update().await?;
+        let finality_update = self.consensus_client.get_finality_update().await?;
         let mut finality_update_generic = Update {
             attested_header: finality_update.attested_header,
             next_sync_committee: None,
@@ -95,9 +97,6 @@ impl LightClient {
         let current_period = calc_sync_period(current_slot);
         let update_period = calc_sync_period(update_slot);
 
-        println!("current period: {}", current_period);
-        println!("update period: {}", update_period);
-
         if !(update_period == current_period + 1 || update_period == current_period) {
             return Err(eyre::eyre!("Invalid Update"));
         }
@@ -106,67 +105,46 @@ impl LightClient {
             return Err(eyre::eyre!("Invalid Update"));
         }
 
-        let finality_header_hash = update.finalized_header.hash_tree_root()?;
-        let update_header_root = Node::from_bytes(update.attested_header.state_root);
-        let finality_branch = branch_to_nodes(update.finality_branch.clone());
-        let finality_branch_valid = is_valid_merkle_branch(&finality_header_hash, finality_branch.iter(), 6, 41, &update_header_root);
-        println!("finality branch valid: {}", finality_branch_valid);
+        let finality_branch_valid = is_finality_proof_valid(
+            &update.attested_header,
+            &mut update.finalized_header,
+            &update.finality_branch
+        );
+
+        if !(finality_branch_valid) {
+            return Err(eyre::eyre!("Invalid Update"));
+        }
 
         if update.next_sync_committee.is_some() {
-            let next_committee_hash = update.next_sync_committee.as_ref().unwrap().clone().hash_tree_root()?;
-            let next_committee_branch = branch_to_nodes(update.next_sync_committee_branch.clone());
-            let next_committee_branch_valid = is_valid_merkle_branch(&next_committee_hash, next_committee_branch.iter(), 5, 23, &update_header_root);
-            println!("next sync committee branch valid: {}", next_committee_branch_valid);
+            let next_committee_branch_valid = is_next_committee_proof_valid(
+                &update.attested_header,
+                &mut update.next_sync_committee.clone().unwrap(),
+                &update.next_sync_committee_branch
+            );
 
             if !next_committee_branch_valid {
                 return Err(eyre::eyre!("Invalid Update"));
             }
         }
 
-        if !(finality_branch_valid) {
-            return Err(eyre::eyre!("Invalid Update"));
-        }
-
         let sync_committee = if current_period == update_period {
             &self.store.current_sync_committee
         } else {
             self.store.next_sync_committee.as_ref().unwrap()
         };
 
-        let bytes = hex::decode(update.sync_aggregate.sync_committee_bits.strip_prefix("0x").unwrap())?;
-        let mut bits = String::new();
-        let mut count = 0;
-        for byte in bytes {
-            let byte_str = format!("{:08b}", byte);
-            byte_str.chars().for_each(|b| if b == '1' { count += 1 });
-            bits.push_str(&byte_str.chars().rev().collect::<String>());
-        }
-
-        let mut pks: Vec<PublicKey> = Vec::new();
-        bits.chars().enumerate().for_each(|(i, bit)| {
-            if bit == '1' {
-                let pk = sync_committee.pubkeys[i].clone();
-                let pk = PublicKey::from_bytes(&pk).unwrap();
-                pks.push(pk)
-            }
-        });
+        let pks = get_participating_keys(sync_committee, &update.sync_aggregate.sync_committee_bits)?;
         let pks: Vec<&PublicKey> = pks.iter().map(|pk| pk).collect();
 
-        let committee_quorum = count as f64 > 2.0 / 3.0 * 512.0;
-        println!("sync committee quorum: {}", committee_quorum);
-
+        let committee_quorum = pks.len() as f64 > 2.0 / 3.0 * 512.0;
         if !committee_quorum {
             return Err(eyre::eyre!("Invalid Update"));
         }
 
         let header_root = bytes_to_bytes32(update.attested_header.hash_tree_root()?.as_bytes());
         let signing_root = compute_committee_sign_root(header_root)?;
-
-        let sig_bytes = hex::decode(update.sync_aggregate.sync_committee_signature.strip_prefix("0x").unwrap())?;
-        let sig = Signature::from_bytes(&sig_bytes).unwrap();
-        let dst: &[u8] = b"BLS_SIG_BLS12381G2_XMD:SHA-256_SSWU_RO_POP_";
-        let is_valid_sig = sig.fast_aggregate_verify(true, signing_root.as_bytes(), dst, &pks) == BLST_ERROR::BLST_SUCCESS;
-        println!("committee signature valid: {}", is_valid_sig);
+        let sig_bytes = hex_str_to_bytes(&update.sync_aggregate.sync_committee_signature)?;
+        let is_valid_sig = is_aggregate_valid(sig_bytes, signing_root.as_bytes(), &pks);
 
         if !is_valid_sig {
             return Err(eyre::eyre!("Invalid Update"));
@@ -189,37 +167,124 @@ impl LightClient {
             self.store.next_sync_committee = Some(update.next_sync_committee.as_ref().unwrap().clone());
         }
     }
-
-    async fn get_bootstrap(rpc: &str, block_root: &str) -> Result<Bootstrap> {
-        let req = format!("{}/eth/v0/beacon/light_client/bootstrap/{}", rpc, block_root);
-        let res = reqwest::get(req).await?.json::<BootstrapResponse>().await?;
-        Ok(res.data.v)
 }
 
-    async fn get_updates(&self, period: u64) -> Result<Vec<Update>> {
-        let req = format!("{}/eth/v0/beacon/light_client/updates?start_period={}&count=1000", self.nimbus_rpc, period);
-        let res = reqwest::get(req).await?.json::<UpdateResponse>().await?;
-        Ok(res.data)
+fn get_participating_keys(committee: &SyncCommittee, bitfield: &str) -> Result<Vec<PublicKey>> {
+        let bytes = hex_str_to_bytes(bitfield)?;
+        let mut pks: Vec<PublicKey> = Vec::new();
+        bytes.iter().enumerate().for_each(|(i, byte)| {
+            format!("{:08b}", byte).chars().rev().enumerate().for_each(|(j, bit)| {
+                if bit == '1' {
+                    let index = 8 * i + j;
+                    let pk = &committee.pubkeys[index];
+                    let pk = PublicKey::from_bytes(&pk).unwrap();
+                    pks.push(pk);
+                }
+            });
+        });
+
+        Ok(pks)
 }
 
-    async fn get_finality_update(&self) -> Result<FinalityUpdate> {
-        let req = format!("{}/eth/v0/beacon/light_client/finality_update", self.nimbus_rpc);
-        let res = reqwest::get(req).await?.json::<FinalityUpdateResponse>().await?;
-        Ok(res.data)
+fn is_aggregate_valid(sig_bytes: Vec<u8>, msg: &[u8], pks: &[&PublicKey]) -> bool {
+    let dst: &[u8] = b"BLS_SIG_BLS12381G2_XMD:SHA-256_SSWU_RO_POP_";
+    let sig_res = Signature::from_bytes(&sig_bytes);
+    match sig_res {
+        Ok(sig) => sig.fast_aggregate_verify(true, msg, dst, &pks) == BLST_ERROR::BLST_SUCCESS,
+        Err(_) => false,
     }
 }
 
+fn is_finality_proof_valid(attested_header: &Header, finality_header: &mut Header, finality_branch: &Vec<Bytes32>) -> bool {
+        let finality_header_hash_res = finality_header.hash_tree_root();
+        if finality_header_hash_res.is_err() {
+            return false;
+        }
+
+        let attested_header_state_root_res = bytes32_to_node(&attested_header.state_root);
+        if attested_header_state_root_res.is_err() {
+            return false;
+        }
+
+        let finality_branch_res = branch_to_nodes(finality_branch.clone());
+        if finality_branch_res.is_err() {
+            return false;
+        }
+
+        is_valid_merkle_branch(
+            &finality_header_hash_res.unwrap(),
+            finality_branch_res.unwrap().iter(),
+            6,
+            41,
+            &attested_header_state_root_res.unwrap()
+        )
+}
+
+fn is_next_committee_proof_valid(
+    attested_header: &Header,
+    next_committee: &mut SyncCommittee,
+    next_committee_branch: &Vec<Bytes32>
+) -> bool {
+    let next_committee_hash_res = next_committee.hash_tree_root();
+    if next_committee_hash_res.is_err() {
+        return false;
+    }
+
+    let attested_header_state_root_res = bytes32_to_node(&attested_header.state_root);
+    if attested_header_state_root_res.is_err() {
+        return false;
+    }
+
+    let next_committee_branch_res = branch_to_nodes(next_committee_branch.clone());
+    if next_committee_branch_res.is_err() {
+        return false;
+    }
+
+    is_valid_merkle_branch(
+        &next_committee_hash_res.unwrap(),
+        next_committee_branch_res.unwrap().iter(),
+        5,
+        23,
+        &attested_header_state_root_res.unwrap()
+    )
+}
+
+fn is_current_committee_proof_valid(
+    attested_header: &Header,
+    current_committee: &mut SyncCommittee,
+    current_committee_branch: &Vec<Bytes32>
+) -> bool {
+    let next_committee_hash_res = current_committee.hash_tree_root();
+    if next_committee_hash_res.is_err() {
+        return false;
+    }
+
+    let attested_header_state_root_res = bytes32_to_node(&attested_header.state_root);
+    if attested_header_state_root_res.is_err() {
+        return false;
+    }
+
+    let next_committee_branch_res = branch_to_nodes(current_committee_branch.clone());
+    if next_committee_branch_res.is_err() {
+        return false;
+    }
+
+    is_valid_merkle_branch(
+        &next_committee_hash_res.unwrap(),
+        next_committee_branch_res.unwrap().iter(),
+        5,
+        22,
+        &attested_header_state_root_res.unwrap()
+    )
+}
+
 fn calc_sync_period(slot: u64) -> u64 {
     let epoch = slot / 32;
     epoch / 256
 }
 
-fn branch_to_nodes(branch: Vec<Bytes32>) -> Vec<Node> {
-    branch.iter().map(|elem| Node::from_bytes(*elem)).collect()
-}
-
-fn bytes_to_bytes32(bytes: &[u8]) -> [u8; 32] {
-    bytes.to_vec().try_into().unwrap()
+fn branch_to_nodes(branch: Vec<Bytes32>) -> Result<Vec<Node>> {
+    branch.iter().map(|elem| bytes32_to_node(elem)).collect::<Result<Vec<Node>>>()
 }
 
 fn compute_committee_sign_root(header: Bytes32) -> Result<Node> {
@@ -230,6 +295,18 @@ fn compute_committee_sign_root(header: Bytes32) -> Result<Node> {
     compute_signing_root(header, domain)
 }
 
+#[derive(SimpleSerialize, Default, Debug)]
+struct SigningData {
+    object_root: Bytes32,
+    domain: Bytes32
+}
+
+#[derive(SimpleSerialize, Default, Debug)]
+struct ForkData {
+    current_version: Vector<u8, 4>,
+    genesis_validator_root: Bytes32,
+}
+
 fn compute_signing_root(object_root: Bytes32, domain: Bytes32) -> Result<Node> {
     let mut data = SigningData { object_root, domain };
     Ok(data.hash_tree_root()?)
@@ -249,132 +326,3 @@ fn compute_fork_data_root(current_version: Vector<u8, 4>, genesis_validator_root
     Ok(fork_data.hash_tree_root()?)
 }
 
-#[derive(SimpleSerialize, Default, Debug)]
-struct ForkData {
-    current_version: Vector<u8, 4>,
-    genesis_validator_root: Bytes32,
-}
-
-#[derive(SimpleSerialize, Default, Debug)]
-struct SigningData {
-    object_root: Bytes32,
-    domain: Bytes32
-}
-
-#[derive(serde::Deserialize, Debug)]
-struct BootstrapResponse {
-    data: BootstrapData,
-}
-
-#[derive(serde::Deserialize, Debug)]
-struct BootstrapData {
-    v: Bootstrap,
-}
-
-#[derive(serde::Deserialize, Debug)]
-struct Bootstrap {
-    header: Header,
-    current_sync_committee: SyncCommittee,
-    #[serde(deserialize_with = "branch_deserialize")]
-    current_sync_committee_branch: Vec<Bytes32>,
-}
-
-#[derive(Debug, Clone, Default, SimpleSerialize, serde::Deserialize)]
-struct SyncCommittee {
-    #[serde(deserialize_with = "pubkeys_deserialize")]
-    pubkeys: Vector<BLSPubKey, 512>,
-    #[serde(deserialize_with = "pubkey_deserialize")]
-    aggregate_pubkey: BLSPubKey,
-}
-
-type BLSPubKey = Vector<u8, 48>;
-type Bytes32 = [u8; 32];
-
-fn pubkey_deserialize<'de, D>(deserializer: D) -> Result<BLSPubKey, D::Error> where D: serde::Deserializer<'de> {
-    let key: String = serde::Deserialize::deserialize(deserializer)?;
-    let key_bytes = hex::decode(key.strip_prefix("0x").unwrap()).unwrap();
-    Ok(Vector::from_iter(key_bytes))
-}
-
-fn pubkeys_deserialize<'de, D>(deserializer: D) -> Result<Vector<BLSPubKey, 512>, D::Error> where D: serde::Deserializer<'de> {
-    let keys: Vec<String> = serde::Deserialize::deserialize(deserializer)?;
-    Ok(keys.iter().map(|key| {
-        let key_bytes = hex::decode(key.strip_prefix("0x").unwrap()).unwrap();
-        Vector::from_iter(key_bytes)
-    }).collect::<Vector<BLSPubKey, 512>>())
-}
-
-fn branch_deserialize<'de, D>(deserializer: D) -> Result<Vec<Bytes32>, D::Error> where D: serde::Deserializer<'de> {
-    let branch: Vec<String> = serde::Deserialize::deserialize(deserializer)?;
-    Ok(branch.iter().map(|elem| {
-        let bytes = hex::decode(elem.strip_prefix("0x").unwrap()).unwrap();
-        bytes.to_vec().try_into().unwrap()
-    }).collect())
-}
-
-#[derive(serde::Deserialize, Debug, Clone, Default, SimpleSerialize)]
-struct Header {
-    #[serde(deserialize_with = "u64_deserialize")]
-    slot: u64,
-    #[serde(deserialize_with = "u64_deserialize")]
-    proposer_index: u64,
-    #[serde(deserialize_with = "bytes32_deserialize")]
-    parent_root: Bytes32,
-    #[serde(deserialize_with = "bytes32_deserialize")]
-    state_root: Bytes32,
-    #[serde(deserialize_with = "bytes32_deserialize")]
-    body_root: Bytes32,
-}
-
-fn u64_deserialize<'de, D>(deserializer: D) -> Result<u64, D::Error> where D: serde::Deserializer<'de> {
-    let val: String = serde::Deserialize::deserialize(deserializer)?;
-    Ok(val.parse().unwrap())
-}
-
-fn bytes32_deserialize<'de, D>(deserializer: D) -> Result<Bytes32, D::Error> where D: serde::Deserializer<'de> {
-    let bytes: String = serde::Deserialize::deserialize(deserializer)?;
-    let bytes = hex::decode(bytes.strip_prefix("0x").unwrap()).unwrap();
-    Ok(bytes.to_vec().try_into().unwrap())
-}
-
-#[derive(serde::Deserialize, Debug)]
-struct UpdateResponse {
-    data: Vec<Update>,
-}
-
-#[derive(serde::Deserialize, Debug, Clone)]
-struct Update {
-    attested_header: Header,
-    next_sync_committee: Option<SyncCommittee>,
-    #[serde(deserialize_with = "branch_deserialize")]
-    next_sync_committee_branch: Vec<Bytes32>,
-    finalized_header: Header,
-    #[serde(deserialize_with = "branch_deserialize")]
-    finality_branch: Vec<Bytes32>,
-    sync_aggregate: SyncAggregate,
-    #[serde(deserialize_with = "u64_deserialize")]
-    signature_slot: u64,
-}
-
-#[derive(serde::Deserialize, Debug, Clone)]
-struct SyncAggregate {
-    sync_committee_bits: String,
-    sync_committee_signature: String,
-}
-
-#[derive(serde::Deserialize, Debug)]
-struct FinalityUpdateResponse {
-    data: FinalityUpdate,
-}
-
-#[derive(serde::Deserialize, Debug)]
-struct FinalityUpdate {
-    attested_header: Header,
-    finalized_header: Header,
-    #[serde(deserialize_with = "branch_deserialize")]
-    finality_branch: Vec<Bytes32>,
-    sync_aggregate: SyncAggregate,
-    #[serde(deserialize_with = "u64_deserialize")]
-    signature_slot: u64,
-}
-

src/utils.rs

@@ -0,0 +1,16 @@
+use eyre::Result;
+use ssz_rs::{Node, Vector};
+use super::consensus_client::Bytes32;
+
+pub fn hex_str_to_bytes(s: &str) -> Result<Vec<u8>> {
+    let stripped = s.strip_prefix("0x").unwrap_or(s);
+    Ok(hex::decode(stripped)?)
+}
+
+pub fn bytes32_to_node(bytes: &Bytes32) -> Result<Node> {
+    Ok(Node::from_bytes(bytes.as_slice().try_into()?))
+}
+
+pub fn bytes_to_bytes32(bytes: &[u8]) -> Bytes32 {
+    Vector::from_iter(bytes.to_vec())
+}