Verify chunk signature (#1862)

x/dsmr/block.go

@@ -4,6 +4,9 @@
 package dsmr
 
 import (
+	"errors"
+	"fmt"
+
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/utils/crypto/bls"
 	"github.com/ava-labs/avalanchego/utils/wrappers"
@@ -16,6 +19,8 @@ import (
 
 const InitialChunkSize = 250 * 1024
 
+var ErrFailedChunkSigVerification = errors.New("failed to verify bls chunk signature")
+
 type Tx interface {
 	GetID() ids.ID
 	GetExpiry() int64
@@ -82,6 +87,35 @@ func signChunk[T Tx](
 	return newChunk(chunk, pkBytes, signature)
 }
 
+func (c *Chunk[T]) Verify(networkID uint32, chainID ids.ID) error {
+	signature, err := bls.SignatureFromBytes(c.Signature[:])
+	if err != nil {
+		return err
+	}
+
+	pk, err := bls.PublicKeyFromCompressedBytes(c.Signer[:])
+	if err != nil {
+		return err
+	}
+
+	// Construct the unsigned message from the UnsignedChunk (stripping the signature fields)
+	packer := wrappers.Packer{Bytes: make([]byte, 0, InitialChunkSize), MaxSize: consts.NetworkSizeLimit}
+	if err := codec.LinearCodec.MarshalInto(c.UnsignedChunk, &packer); err != nil {
+		return err
+	}
+
+	msg, err := warp.NewUnsignedMessage(networkID, chainID, packer.Bytes)
+	if err != nil {
+		return fmt.Errorf("failed to create unsigned warp message from chunk: %w", err)
+	}
+
+	if !bls.Verify(pk, signature, msg.Bytes()) {
+		return ErrFailedChunkSigVerification
+	}
+
+	return nil
+}
+
 // newChunk signs a chunk
 func newChunk[T Tx](
 	unsignedChunk UnsignedChunk[T],

x/dsmr/node_test.go

@@ -439,8 +439,11 @@ func TestNode_GetChunkSignature_SignValidChunk(t *testing.T) {
 			wantErr:  ErrInvalidChunk,
 		},
 		{
-			name:     "valid chunk",
-			verifier: NoVerifier[dsmrtest.Tx]{},
+			name: "valid chunk",
+			verifier: ChunkVerifier[dsmrtest.Tx]{
+				networkID: networkID,
+				chainID:   chainID,
+			},
 		},
 	}
 
@@ -514,22 +517,19 @@ func TestNode_GetChunkSignature_SignValidChunk(t *testing.T) {
 			)
 			r.NoError(err)
 
-			chunk, err := newChunk[dsmrtest.Tx](
-				UnsignedChunk[dsmrtest.Tx]{
-					Producer:    ids.GenerateTestNodeID(),
-					Beneficiary: codec.Address{123},
-					Expiry:      123,
-					Txs: []dsmrtest.Tx{
-						{
-							ID:      ids.GenerateTestID(),
-							Expiry:  456,
-							Sponsor: codec.Address{4, 5, 6},
-						},
+			unsignedChunk := UnsignedChunk[dsmrtest.Tx]{
+				Producer:    ids.GenerateTestNodeID(),
+				Beneficiary: codec.Address{123},
+				Expiry:      123,
+				Txs: []dsmrtest.Tx{
+					{
+						ID:      ids.GenerateTestID(),
+						Expiry:  456,
+						Sponsor: codec.Address{4, 5, 6},
 					},
 				},
-				[48]byte{},
-				[96]byte{},
-			)
+			}
+			chunk, err := signChunk[dsmrtest.Tx](unsignedChunk, networkID, chainID, pk, signer)
 			r.NoError(err)
 
 			packer := wrappers.Packer{MaxSize: MaxMessageSize}
@@ -1261,16 +1261,19 @@ func newTestNodes(t *testing.T, n int) []*Node[dsmrtest.Tx] {
 		require.NoError(t, err)
 		pk := bls.PublicFromSecretKey(sk)
 		signer := warp.NewSigner(sk, networkID, chainID)
-
-		chunkStorage, err := NewChunkStorage[dsmrtest.Tx](NoVerifier[dsmrtest.Tx]{}, memdb.New())
+		verifier := ChunkVerifier[dsmrtest.Tx]{networkID: networkID, chainID: chainID}
+		chunkStorage, err := NewChunkStorage[dsmrtest.Tx](verifier, memdb.New())
 		require.NoError(t, err)
 
 		getChunkHandler := &GetChunkHandler[dsmrtest.Tx]{
 			storage: chunkStorage,
 		}
 		chunkSignatureRequestHandler := acp118.NewHandler(ChunkSignatureRequestVerifier[dsmrtest.Tx]{
-			verifier: NoVerifier[dsmrtest.Tx]{},
-			storage:  chunkStorage,
+			verifier: ChunkVerifier[dsmrtest.Tx]{
+				networkID: networkID,
+				chainID:   chainID,
+			},
+			storage: chunkStorage,
 		}, signer)
 		chunkCertificateGossipHandler := ChunkCertificateGossipHandler[dsmrtest.Tx]{
 			storage: chunkStorage,

x/dsmr/p2p.go

@@ -131,6 +131,7 @@ func (c ChunkSignatureRequestVerifier[T]) Verify(
 		return ErrInvalidChunk
 	}
 
+	// check to see if this chunk was already accepted.
 	_, accepted, err := c.storage.GetChunkBytes(chunk.Expiry, chunk.id)
 	if err != nil && !errors.Is(err, database.ErrNotFound) {
 		return &common.AppError{

x/dsmr/storage.go

@@ -32,12 +32,23 @@ type Verifier[T Tx] interface {
 	Verify(chunk Chunk[T]) error
 }
 
-var _ Verifier[Tx] = (*NoVerifier[Tx])(nil)
+var _ Verifier[Tx] = (*ChunkVerifier[Tx])(nil)
 
-type NoVerifier[T Tx] struct{}
+type ChunkVerifier[T Tx] struct {
+	networkID uint32
+	chainID   ids.ID
+}
 
-func (NoVerifier[T]) Verify(Chunk[T]) error {
-	return nil
+func (c ChunkVerifier[T]) Verify(chunk Chunk[T]) error {
+	// TODO:
+	// check if the expiry of this chunk isn't in the past or too far into the future.
+
+	// TODO:
+	// check if the producer was expected to produce this chunk.
+
+	// TODO:
+	// add rate limiting for a given producer.
+	return chunk.Verify(c.networkID, c.chainID)
 }
 
 type StoredChunkSignature[T Tx] struct {