EIP-7549: Allow multiple committee bits

proto/prysm/v1alpha1/attestation/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//crypto/bls:go_default_library",
+        "//crypto/hash:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "@com_github_pkg_errors//:go_default_library",

proto/prysm/v1alpha1/attestation/id.go

@@ -1,11 +1,12 @@
 package attestation
 
 import (
-	"fmt"
+	"strconv"
+	"strings"
 
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/hash"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 )
@@ -44,19 +45,21 @@ func NewId(att ethpb.Att, source IdSource) (Id, error) {
 		copy(id[1:], h[:])
 		return id, nil
 	case Data:
-		data := att.GetData()
+		dataHash, err := att.GetData().HashTreeRoot()
+		if err != nil {
+			return Id{}, err
+		}
+		h := dataHash
 		if att.Version() >= version.Electra {
 			committeeIndices := att.CommitteeBitsVal().BitIndices()
-			if len(committeeIndices) != 1 {
-				return Id{}, fmt.Errorf("%d committee bits are set instead of 1", len(committeeIndices))
+			if len(committeeIndices) == 0 {
+				return Id{}, errors.New("no committee bits are set")
 			}
-			dataCopy := ethpb.CopyAttestationData(att.GetData())
-			dataCopy.CommitteeIndex = primitives.CommitteeIndex(committeeIndices[0])
-			data = dataCopy
-		}
-		h, err := data.HashTreeRoot()
-		if err != nil {
-			return Id{}, err
+			stringCommitteeIndices := make([]string, len(committeeIndices))
+			for i, ix := range committeeIndices {
+				stringCommitteeIndices[i] = strconv.Itoa(ix)
+			}
+			h = hash.Hash(append(dataHash[:], []byte(strings.Join(stringCommitteeIndices, ","))...))
 		}
 		copy(id[1:], h[:])
 		return id, nil

proto/prysm/v1alpha1/attestation/id_test.go

@@ -41,6 +41,22 @@ func TestNewId(t *testing.T) {
 
 		assert.NotEqual(t, phase0Id, electraId)
 	})
+	t.Run("ID is different for different committee bits", func(t *testing.T) {
+		cb := primitives.NewAttestationCommitteeBits()
+		cb.SetBitAt(0, true)
+		cb.SetBitAt(1, true)
+		att := util.HydrateAttestationElectra(&ethpb.AttestationElectra{CommitteeBits: cb})
+		id1, err := attestation.NewId(att, attestation.Data)
+		assert.NoError(t, err)
+		cb = primitives.NewAttestationCommitteeBits()
+		cb.SetBitAt(0, true)
+		cb.SetBitAt(2, true)
+		att = util.HydrateAttestationElectra(&ethpb.AttestationElectra{CommitteeBits: cb})
+		id2, err := attestation.NewId(att, attestation.Data)
+		assert.NoError(t, err)
+
+		assert.NotEqual(t, id1, id2)
+	})
 	t.Run("invalid source", func(t *testing.T) {
 		att := util.HydrateAttestation(&ethpb.Attestation{})
 		_, err := attestation.NewId(att, 123)
@@ -50,14 +66,6 @@ func TestNewId(t *testing.T) {
 		cb := primitives.NewAttestationCommitteeBits()
 		att := util.HydrateAttestationElectra(&ethpb.AttestationElectra{CommitteeBits: cb})
 		_, err := attestation.NewId(att, attestation.Data)
-		assert.ErrorContains(t, "0 committee bits are set", err)
-	})
-	t.Run("data source Electra - multiple bits set", func(t *testing.T) {
-		cb := primitives.NewAttestationCommitteeBits()
-		cb.SetBitAt(0, true)
-		cb.SetBitAt(1, true)
-		att := util.HydrateAttestationElectra(&ethpb.AttestationElectra{CommitteeBits: cb})
-		_, err := attestation.NewId(att, attestation.Data)
-		assert.ErrorContains(t, "2 committee bits are set", err)
+		assert.ErrorContains(t, "no committee bits are set", err)
 	})
 }