add blob verification function, hash validation for blob tx parsing, …

…and test tweaks (#5)

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=
@@ -345,6 +349,8 @@ github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+Gx
 github.com/prometheus/procfs v0.0.11/go.mod h1:lV6e/gmhEcM9IjHGsFOCxxuZ+z1YqCvr4OA4YeYWdaU=
 github.com/quasilyte/go-ruleguard/dsl v0.3.22 h1:wd8zkOhSNr+I+8Qeciml08ivDt1pSXe60+5DqOpCjPE=
 github.com/quasilyte/go-ruleguard/dsl v0.3.22/go.mod h1:KeCP03KrjuSO0H1kTuZQCWlQPulDV6YMIXmpQss17rU=
+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=
@@ -494,6 +500,7 @@ 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
+}