add blob verification function + hash validation for blob tx parsing

go.mod

@@ -69,7 +69,9 @@ require (
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/gorilla/websocket v1.5.0 // indirect
+	github.com/herumi/bls-eth-go-binary v1.28.1 // indirect
 	github.com/huandu/xstrings v1.3.2 // indirect
+	github.com/kilic/bls12-381 v0.1.1-0.20220929213557-ca162e8a70f4 // indirect
 	github.com/lispad/go-generics-tools v1.1.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.17 // indirect
@@ -93,6 +95,7 @@ require (
 	github.com/pion/webrtc/v3 v3.1.42 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/protolambda/go-kzg v0.0.0-20221224134646-c91cee5e954e // indirect
 	github.com/protolambda/ztyp v0.2.2 // indirect
 	github.com/rs/dnscache v0.0.0-20211102005908-e0241e321417 // indirect
 	github.com/valyala/fastrand v1.1.0 // indirect

go.sum

@@ -208,6 +208,8 @@ github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFb
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.5-0.20210104140557-80c98217689d h1:dg1dEPuWpEqDnvIw251EVy4zlP8gWbsGj4BsUKCRpYs=
 github.com/hashicorp/golang-lru v0.5.5-0.20210104140557-80c98217689d/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
+github.com/herumi/bls-eth-go-binary v1.28.1 h1:fcIZ48y5EE9973k05XjE8+P3YiQgjZz4JI/YabAm8KA=
+github.com/herumi/bls-eth-go-binary v1.28.1/go.mod h1:luAnRm3OsMQeokhGzpYmc0ZKwawY7o87PUEP11Z7r7U=
 github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
 github.com/holiman/uint256 v1.2.0/go.mod h1:y4ga/t+u+Xwd7CpDgZESaRcWy0I7XMlTMA25ApIH5Jw=
 github.com/holiman/uint256 v1.2.1 h1:XRtyuda/zw2l+Bq/38n5XUoEF72aSOu/77Thd9pPp2o=
@@ -224,6 +226,8 @@ github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/u
 github.com/jtolds/gls v4.2.1+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
+github.com/kilic/bls12-381 v0.1.1-0.20220929213557-ca162e8a70f4 h1:xWK4TZ4bRL05WQUU/3x6TG1l+IYAqdXpAeSLt/zZJc4=
+github.com/kilic/bls12-381 v0.1.1-0.20220929213557-ca162e8a70f4/go.mod h1:tlkavyke+Ac7h8R3gZIjI5LKBcvMlSWnXNMgT3vZXo8=
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
@@ -343,6 +347,8 @@ github.com/prometheus/procfs v0.0.0-20190117184657-bf6a532e95b1/go.mod h1:c3At6R
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
 github.com/prometheus/procfs v0.0.11/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
+github.com/protolambda/go-kzg v0.0.0-20221224134646-c91cee5e954e h1:Wed8Zc7HuSVNDJQy6ybac5/1fpRoyhMDcPvGlMjyIiY=
+github.com/protolambda/go-kzg v0.0.0-20221224134646-c91cee5e954e/go.mod h1:7EhkBJFo/qJ9sToiW5baPqbyPo/TadVHn4iNdpwEW/w=
 github.com/protolambda/ztyp v0.2.2 h1:rVcL3vBu9W/aV646zF6caLS/dyn9BN8NYiuJzicLNyY=
 github.com/protolambda/ztyp v0.2.2/go.mod h1:9bYgKGqg3wJqT9ac1gI2hnVb0STQq7p/1lapqrqY1dU=
 github.com/quasilyte/go-ruleguard/dsl v0.3.21 h1:vNkC6fC6qMLzCOGbnIHOd5ixUGgTbp3Z4fGnUgULlDA=
@@ -492,6 +498,7 @@ golang.org/x/sys v0.0.0-20200923182605-d9f96fdee20d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210112080510-489259a85091/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

types/blob_txn.go

@@ -6,16 +6,21 @@ import (
 	"fmt"
 
 	"github.com/holiman/uint256"
+	"github.com/protolambda/go-kzg/eth"
 	"github.com/protolambda/ztyp/codec"
 	"github.com/protolambda/ztyp/view"
 )
 
 const (
 	FieldElementsPerBlob = 4096
 
-	BlobSize = FieldElementsPerBlob * 32 // blob size in bytes - each field element is 32 bytes
+	FieldElementSize = 32
+
+	BlobSize = FieldElementsPerBlob * FieldElementSize // blob size in bytes
 
 	ProofSize = 48 // kzg proof size
+
+	MaxBlobsPerBlock = 4
 )
 
 type BlobTxNetworkWrapper struct {
@@ -303,3 +308,51 @@ func (sig *ECDSASignature) Deserialize(dr *codec.DecodingReader) error {
 	copy(sig.S[:], data[33:len])
 	return nil
 }
+
+type blobSequence [][BlobSize]byte
+
+func (s blobSequence) At(i int) eth.Blob { return blob(s[i]) }
+func (s blobSequence) Len() int          { return len(s) }
+
+type blob [BlobSize]byte
+
+func (s blob) At(i int) [FieldElementSize]byte {
+	r := [FieldElementSize]byte{}
+	if i*FieldElementSize+FieldElementSize > len(s) {
+		return r
+	}
+	copy(r[:], s[i*FieldElementSize:i*FieldElementSize+FieldElementSize])
+	return r
+}
+func (s blob) Len() int { return len(s) / FieldElementSize }
+
+type kzgSequence [][ProofSize]byte
+
+func (s kzgSequence) At(i int) eth.KZGCommitment { return eth.KZGCommitment(s[i]) }
+func (s kzgSequence) Len() int                   { return len(s) }
+
+func VerifyBlobs(blobKZGs [][ProofSize]byte, blobs [][BlobSize]byte, kzgAggregatedProof [ProofSize]byte, blobVersionedHashes [][32]byte) error {
+	l1 := len(blobKZGs)
+	l2 := len(blobs)
+	l3 := len(blobVersionedHashes)
+	if l1 != l2 || l2 != l3 {
+		return fmt.Errorf("lengths don't match %v %v %v", l1, l2, l3)
+	}
+	if l1 > MaxBlobsPerBlock {
+		return fmt.Errorf("number of blobs exceeds max: %v", l1)
+	}
+	ok, err := eth.VerifyAggregateKZGProof(blobSequence(blobs), kzgSequence(blobKZGs), eth.KZGProof(kzgAggregatedProof))
+	if err != nil {
+		return fmt.Errorf("error during proof verification: %v", err)
+	}
+	if !ok {
+		return fmt.Errorf("failed to verify kzg")
+	}
+	for i, h := range blobVersionedHashes {
+		computed := eth.KZGToVersionedHash(eth.KZGCommitment(blobKZGs[i]))
+		if computed != h {
+			return fmt.Errorf("versioned hash %d supposedly %s but does not match computed %s", i, h, computed)
+		}
+	}
+	return nil
+}

types/blob_txn_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/protolambda/ztyp/codec"
+	"github.com/stretchr/testify/require"
 
 	"github.com/ledgerwatch/erigon-lib/common"
 )
@@ -138,4 +139,24 @@ func TestParseBlobTxNetworkWrapper(t *testing.T) {
 	if l1 != 2 || l2 != 2 || l3 != 2 {
 		t.Errorf("Expected 2 each of kzgs / blobs / hashes, got: %v %v %v", l1, l2, l3)
 	}
+
+	// Test blob verification
+	err = VerifyBlobs(tx.BlobKZGs, tx.Blobs, tx.KZGAggregatedProof, tx.Tx.Message.BlobVersionedHashes)
+	require.NoError(t, err)
+
+	// Mangle one byte in a blob and make sure verification fails
+	oldByte := tx.Blobs[0][10]
+	tx.Blobs[0][10] = 0
+	err = VerifyBlobs(tx.BlobKZGs, tx.Blobs, tx.KZGAggregatedProof, tx.Tx.Message.BlobVersionedHashes)
+	if err == nil {
+		t.Fatal("Expected error when verifying invalid blob data, got none")
+	}
+	tx.Blobs[0][10] = oldByte
+
+	// Mangle one byte in the proof and make sure verification failse
+	tx.KZGAggregatedProof[10] = 0
+	err = VerifyBlobs(tx.BlobKZGs, tx.Blobs, tx.KZGAggregatedProof, tx.Tx.Message.BlobVersionedHashes)
+	if err == nil {
+		t.Fatal("Expected error when verifying invalid aggregated proof, got none")
+	}
 }

types/txn.go

@@ -160,7 +160,7 @@ func (ctx *TxParseContext) ParseTransaction(payload []byte, pos int, slot *TxSlo
 			// since it is SSZ format. We assume the scope ends at the last byte of the payload
 			// argument; this currently seems to always be the case, but does not seem to be
 			// mandated by this function's contract.
-			return len(payload), ctx.ParseBlobTransaction(payload[p:], slot, sender)
+			return len(payload), ctx.ParseBlobTransaction(payload[p:], slot, sender, validateHash)
 		}
 		if _, err = ctx.Keccak1.Write(payload[p : p+1]); err != nil {
 			return 0, fmt.Errorf("%w: computing IdHash (hashing type Prefix): %s", ErrParseTxn, err)
@@ -480,10 +480,15 @@ func (ctx *TxParseContext) ParseTransaction(payload []byte, pos int, slot *TxSlo
 	return p, nil
 }
 
-func (ctx *TxParseContext) ParseBlobTransaction(payload []byte, slot *TxSlot, sender []byte) error {
+func (ctx *TxParseContext) ParseBlobTransaction(payload []byte, slot *TxSlot, sender []byte, validateHash func([]byte) error) error {
 	slot.Rlp = payload // includes type byte
 	ctx.Keccak1.Write(payload)
 	ctx.Keccak1.(io.Reader).Read(slot.IDHash[:32])
+	if validateHash != nil {
+		if err := validateHash(slot.IDHash[:32]); err != nil {
+			return err
+		}
+	}
 
 	payload = payload[1:]
 	// payload should now include the SSZ encoded tx and nothing more

types/txn_test.go

@@ -35,17 +35,19 @@ func TestParseBlobTransaction(t *testing.T) {
 	ctx := NewTxParseContext(*new(uint256.Int).SetUint64(1))
 	tx, txSender := &TxSlot{}, [20]byte{}
 
-	// Prepare the payload, which is an RLP encoded string consisting of the blob tx type byte
-	// followed by the ssz encoded transaction data.
 	ssz := common.MustDecodeHex(strings.TrimSpace(blobTxNetworkWrapperHex))
-	stringLen := rlp.StringLen(len(ssz) + 1)
-	payload := make([]byte, stringLen)
-	rlp.EncodeString(append([]byte{byte(BlobTxType)}, ssz...), payload)
+	payload := append([]byte{byte(BlobTxType)}, ssz...)
 	parseEnd, err := ctx.ParseTransaction(payload, 0, tx, txSender[:], false /* hasEnvelope */, nil)
 
 	require.NoError(err)
 	require.Equal(len(payload), parseEnd)
 
+	// Same test only with an rlp tx envelope.
+	stringLen := rlp.StringLen(len(ssz) + 1)
+	payload = make([]byte, stringLen)
+	rlp.EncodeString(append([]byte{byte(BlobTxType)}, ssz...), payload)
+	parseEnd, err = ctx.ParseTransaction(payload, 0, tx, txSender[:], true /* hasEnvelope */, nil)
+
 	// TODO: test that tx fields are set properly. Need a better input transaction as this example
 	// has zeros for all fields other than the blobs.
 }