op-service/sources: detect duplicate blob hashes

op-service/sources/l1_beacon_client.go

@@ -9,7 +9,6 @@ import (
 	"net/http"
 	"net/url"
 	"path"
-	"slices"
 	"strconv"
 	"sync"
 
@@ -344,9 +343,13 @@ func (cl *L1BeaconClient) beaconBlobs(ctx context.Context, slot uint64, hashes [
 			return nil, fmt.Errorf("compute blob kzg commitment: %w", err)
 		}
 		got := eth.KZGToVersionedHash(commitment)
-		idx := slices.IndexFunc(hashes, func(indexedHash eth.IndexedBlobHash) bool {
-			return got == indexedHash.Hash
-		})
+		idx := -1
+		for i, indexedHash := range hashes {
+			if got == indexedHash.Hash && blobs[i] == nil {
+				idx = i
+				break
+			}
+		}
 		if idx == -1 {
 			return nil, fmt.Errorf("received a blob hash that does not match any expected hash: %s", got)
 		}

op-service/sources/l1_beacon_client_test.go

@@ -393,3 +393,39 @@ func TestGetBlobs(t *testing.T) {
 		})
 	}
 }
+
+func TestRequestDuplicateBlobHashes(t *testing.T) {
+	ctx := context.Background()
+	p := mocks.NewBeaconClient(t)
+	p.EXPECT().BeaconGenesis(ctx).Return(eth.APIGenesisResponse{Data: eth.ReducedGenesisData{GenesisTime: 10}}, nil)
+	p.EXPECT().ConfigSpec(ctx).Return(eth.APIConfigResponse{Data: eth.ReducedConfigData{SecondsPerSlot: 2}}, nil)
+	client := NewL1BeaconClient(p, L1BeaconClientConfig{})
+	ref := eth.L1BlockRef{Time: 12}
+
+	hash0, sidecar0 := makeTestBlobSidecar(0)
+	hash1, sidecar1 := makeTestBlobSidecar(1)
+	hash2, sidecar2 := makeTestBlobSidecar(2)
+	sameHash := eth.IndexedBlobHash{
+		Index: 3,
+		Hash:  hash0.Hash,
+	}
+	sameHashSidecar := &eth.BlobSidecar{
+		Blob:          sidecar0.Blob,
+		Index:         eth.Uint64String(sameHash.Index),
+		KZGCommitment: sidecar0.KZGCommitment,
+		KZGProof:      sidecar0.KZGProof,
+	}
+	hashes := []eth.IndexedBlobHash{hash0, hash2, hash1, sameHash} // Mix up the order.
+	beaconBlobs := []*eth.Blob{&sidecar0.Blob, &sidecar1.Blob, &sidecar2.Blob, &sameHashSidecar.Blob}
+
+	invalidBlob0 := sidecar0.Blob
+	invalidBlob0[10]++
+
+	// construct the mock response for the beacon blobs call
+	beaconBlobsResponse := eth.APIBeaconBlobsResponse{Data: beaconBlobs}
+	p.EXPECT().BeaconBlobs(ctx, uint64(1), hashes).Return(beaconBlobsResponse, nil)
+
+	resp, err := client.GetBlobs(ctx, ref, hashes)
+	require.NoError(t, err)
+	require.Equal(t, []*eth.Blob{&sidecar0.Blob, &sidecar2.Blob, &sidecar1.Blob, &sameHashSidecar.Blob}, resp)
+}