Attribute invalid column proof error to correct peer (#6377)

* Attribute invalid column proof error to correct peer

* Update beacon_node/beacon_chain/src/data_availability_checker.rs

Co-authored-by: Pawan Dhananjay <pawandhananjay@gmail.com>

* fix conflicts

beacon_node/beacon_chain/src/data_availability_checker.rs

@@ -24,8 +24,8 @@ mod overflow_lru_cache;
 mod state_lru_cache;
 
 use crate::data_column_verification::{
-    verify_kzg_for_data_column_list, CustodyDataColumn, GossipVerifiedDataColumn,
-    KzgVerifiedCustodyDataColumn, KzgVerifiedDataColumn,
+    verify_kzg_for_data_column, verify_kzg_for_data_column_list, CustodyDataColumn,
+    GossipVerifiedDataColumn, KzgVerifiedCustodyDataColumn, KzgVerifiedDataColumn,
 };
 pub use error::{Error as AvailabilityCheckError, ErrorCategory as AvailabilityCheckErrorCategory};
 use types::non_zero_usize::new_non_zero_usize;
@@ -195,12 +195,15 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
             .now_duration()
             .ok_or(AvailabilityCheckError::SlotClockError)?;
 
+        // Note: currently not reporting which specific blob is invalid because we fetch all blobs
+        // from the same peer for both lookup and range sync.
+
         let verified_blobs = KzgVerifiedBlobList::new(
             Vec::from(blobs).into_iter().flatten(),
             &self.kzg,
             seen_timestamp,
         )
-        .map_err(AvailabilityCheckError::Kzg)?;
+        .map_err(AvailabilityCheckError::InvalidBlobs)?;
 
         self.availability_cache
             .put_kzg_verified_blobs(block_root, epoch, verified_blobs)
@@ -217,13 +220,15 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
     ) -> Result<(Availability<T::EthSpec>, DataColumnsToPublish<T::EthSpec>), AvailabilityCheckError>
     {
         // TODO(das): report which column is invalid for proper peer scoring
-        // TODO(das): batch KZG verification here
+        // TODO(das): batch KZG verification here, but fallback into checking each column
+        // individually to report which column(s) are invalid.
         let verified_custody_columns = custody_columns
             .into_iter()
             .map(|column| {
+                let index = column.index;
                 Ok(KzgVerifiedCustodyDataColumn::from_asserted_custody(
                     KzgVerifiedDataColumn::new(column, &self.kzg)
-                        .map_err(AvailabilityCheckError::Kzg)?,
+                        .map_err(|e| AvailabilityCheckError::InvalidColumn(index, e))?,
                 ))
             })
             .collect::<Result<Vec<_>, AvailabilityCheckError>>()?;
@@ -308,7 +313,7 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
         if self.blobs_required_for_block(&block) {
             return if let Some(blob_list) = blobs.as_ref() {
                 verify_kzg_for_blob_list(blob_list.iter(), &self.kzg)
-                    .map_err(AvailabilityCheckError::Kzg)?;
+                    .map_err(AvailabilityCheckError::InvalidBlobs)?;
                 Ok(MaybeAvailableBlock::Available(AvailableBlock {
                     block_root,
                     block,
@@ -323,13 +328,12 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
         }
         if self.data_columns_required_for_block(&block) {
             return if let Some(data_column_list) = data_columns.as_ref() {
-                verify_kzg_for_data_column_list(
+                verify_kzg_for_data_column_list_with_scoring(
                     data_column_list
                         .iter()
                         .map(|custody_column| custody_column.as_data_column()),
                     &self.kzg,
-                )
-                .map_err(AvailabilityCheckError::Kzg)?;
+                )?;
                 Ok(MaybeAvailableBlock::Available(AvailableBlock {
                     block_root,
                     block,
@@ -380,7 +384,8 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
 
         // verify kzg for all blobs at once
         if !all_blobs.is_empty() {
-            verify_kzg_for_blob_list(all_blobs.iter(), &self.kzg)?;
+            verify_kzg_for_blob_list(all_blobs.iter(), &self.kzg)
+                .map_err(AvailabilityCheckError::InvalidBlobs)?;
         }
 
         let all_data_columns = blocks
@@ -396,7 +401,8 @@ impl<T: BeaconChainTypes> DataAvailabilityChecker<T> {
 
         // verify kzg for all data columns at once
         if !all_data_columns.is_empty() {
-            verify_kzg_for_data_column_list(all_data_columns.iter(), &self.kzg)?;
+            // TODO: Need to also attribute which specific block is faulty
+            verify_kzg_for_data_column_list_with_scoring(all_data_columns.iter(), &self.kzg)?;
         }
 
         for block in blocks {
@@ -598,6 +604,32 @@ async fn availability_cache_maintenance_service<T: BeaconChainTypes>(
     }
 }
 
+fn verify_kzg_for_data_column_list_with_scoring<'a, E: EthSpec, I>(
+    data_column_iter: I,
+    kzg: &'a Kzg,
+) -> Result<(), AvailabilityCheckError>
+where
+    I: Iterator<Item = &'a Arc<DataColumnSidecar<E>>> + Clone,
+{
+    let Err(batch_err) = verify_kzg_for_data_column_list(data_column_iter.clone(), kzg) else {
+        return Ok(());
+    };
+
+    let data_columns = data_column_iter.collect::<Vec<_>>();
+    // Find which column is invalid. If len is 1 or 0 continue to default case below.
+    // If len > 1 at least one column MUST fail.
+    if data_columns.len() > 1 {
+        for data_column in data_columns {
+            if let Err(e) = verify_kzg_for_data_column(data_column.clone(), kzg) {
+                return Err(AvailabilityCheckError::InvalidColumn(data_column.index, e));
+            }
+        }
+    }
+
+    // len 0 should never happen
+    Err(AvailabilityCheckError::InvalidColumn(0, batch_err))
+}
+
 /// A fully available block that is ready to be imported into fork choice.
 #[derive(Clone, Debug, PartialEq)]
 pub struct AvailableBlock<E: EthSpec> {

beacon_node/beacon_chain/src/data_availability_checker/error.rs

@@ -1,10 +1,11 @@
 use kzg::{Error as KzgError, KzgCommitment};
-use types::{BeaconStateError, Hash256};
+use types::{BeaconStateError, ColumnIndex, Hash256};
 
 #[derive(Debug)]
 pub enum Error {
-    Kzg(KzgError),
-    KzgVerificationFailed,
+    InvalidBlobs(KzgError),
+    InvalidColumn(ColumnIndex, KzgError),
+    ReconstructColumnsError(KzgError),
     KzgCommitmentMismatch {
         blob_commitment: KzgCommitment,
         block_commitment: KzgCommitment,
@@ -46,11 +47,12 @@ impl Error {
             | Error::UnableToDetermineImportRequirement
             | Error::RebuildingStateCaches(_)
             | Error::SlotClockError => ErrorCategory::Internal,
-            Error::Kzg(_)
+            Error::InvalidBlobs { .. }
+            | Error::InvalidColumn { .. }
+            | Error::ReconstructColumnsError { .. }
             | Error::BlobIndexInvalid(_)
             | Error::DataColumnIndexInvalid(_)
-            | Error::KzgCommitmentMismatch { .. }
-            | Error::KzgVerificationFailed => ErrorCategory::Malicious,
+            | Error::KzgCommitmentMismatch { .. } => ErrorCategory::Malicious,
         }
     }
 }
@@ -78,9 +80,3 @@ impl From<state_processing::BlockReplayError> for Error {
         Self::BlockReplayError(value)
     }
 }
-
-impl From<KzgError> for Error {
-    fn from(value: KzgError) -> Self {
-        Self::Kzg(value)
-    }
-}

beacon_node/beacon_chain/src/data_availability_checker/overflow_lru_cache.rs

@@ -555,7 +555,8 @@ impl<T: BeaconChainTypes> DataAvailabilityCheckerInner<T> {
                     kzg,
                     pending_components.verified_data_columns.as_slice(),
                     &self.spec,
-                )?;
+                )
+                .map_err(AvailabilityCheckError::ReconstructColumnsError)?;
 
                 let data_columns_to_publish = all_data_columns
                     .iter()