fix: response checking from RequestManager for blobs

beacon_chain/spec/helpers.nim

@@ -10,6 +10,7 @@
 # Uncategorized helper functions from the spec
 
 import
+  std/sequtils,
   # Status libraries
   stew/[byteutils, endians2, objects],
   nimcrypto/sha2,

beacon_chain/sync/request_manager.nim

@@ -18,6 +18,7 @@ import
   "."/sync_protocol, "."/sync_manager,
   ../gossip_processing/block_processor
 
+from std/algorithm import binarySearch
 from ../beacon_clock import GetBeaconTimeFn
 export block_quarantine, sync_manager
 
@@ -102,21 +103,33 @@ proc checkResponse(roots: openArray[Eth2Digest],
       checks.del(res)
   true
 
+func cmpSidecarIdentifier(x: BlobIdentifier | DataColumnIdentifier,
+                          y: ref BlobSidecar | ref DataColumnSidecar): int =
+  cmp(x.index, y.index)
+
 proc checkResponse(idList: seq[BlobIdentifier],
                    blobs: openArray[ref BlobSidecar]): bool =
-  if len(blobs) > len(idList):
+  if blobs.len > idList.len:
     return false
-  for blob in blobs:
-    let block_root = hash_tree_root(blob.signed_block_header.message)
-    var found = false
-    for id in idList:
-      if id.block_root == block_root and id.index == blob.index:
-        found = true
-        break
-    if not found:
+  var i = 0
+  while i < blobs.len:
+    let
+      block_root = hash_tree_root(blobs[i].signed_block_header.message)
+      id = idList[i]
+
+    # Check if the blob response is a subset
+    if binarySearch(idList, blobs[i], cmpSidecarIdentifier) == -1:
+      i = if i != blobs.len - 1: i + 2 else: i + 1
+      continue
+
+    # Verify block_root and index match
+    if id.block_root != block_root or id.index != blobs[i].index:
       return false
-    blob[].verify_blob_sidecar_inclusion_proof().isOkOr:
+
+    # Verify inclusion proof
+    blobs[i][].verify_blob_sidecar_inclusion_proof().isOkOr:
       return false
+    inc i
   true
 
 proc requestBlocksByRoot(rman: RequestManager, items: seq[Eth2Digest]) {.async: (raises: [CancelledError]).} =