[WIP] Demo batch verification function

part of #614

blssig/aggregation.go

@@ -131,6 +131,6 @@ func (v *Verifier) Aggregate(pubkeys []gpbft.PubKey) (_agg gpbft.Aggregate, _err
 	}
 	return &aggregation{
 		mask:   cmask,
-		scheme: v.scheme,
+		scheme: v.bdnScheme,
 	}, nil
 }

blssig/verifier.go

@@ -10,17 +10,20 @@ import (
 	"github.com/drand/kyber"
 	bls12381 "github.com/drand/kyber-bls12381"
 	"github.com/drand/kyber/pairing"
+	"github.com/drand/kyber/sign"
 	"github.com/drand/kyber/sign/bdn"
+	"github.com/drand/kyber/sign/bls"
 	"go.opentelemetry.io/otel/metric"
 
 	"github.com/filecoin-project/go-f3/gpbft"
 	"github.com/filecoin-project/go-f3/internal/measurements"
 )
 
 type Verifier struct {
-	suite    pairing.Suite
-	scheme   *bdn.Scheme
-	keyGroup kyber.Group
+	suite     pairing.Suite
+	bdnScheme *bdn.Scheme
+	blsScheme sign.AggregatableScheme
+	keyGroup  kyber.Group
 
 	mu         sync.RWMutex
 	pointCache map[string]kyber.Point
@@ -29,9 +32,9 @@ type Verifier struct {
 func VerifierWithKeyOnG1() *Verifier {
 	suite := bls12381.NewBLS12381Suite()
 	return &Verifier{
-		suite:    suite,
-		scheme:   bdn.NewSchemeOnG2(suite),
-		keyGroup: suite.G1(),
+		suite:     suite,
+		bdnScheme: bdn.NewSchemeOnG2(suite),
+		keyGroup:  suite.G1(),
 	}
 }
 
@@ -103,5 +106,43 @@ func (v *Verifier) Verify(pubKey gpbft.PubKey, msg, sig []byte) (_err error) {
 		return fmt.Errorf("unarshalling public key: %w", err)
 	}
 
-	return v.scheme.Verify(point, msg, sig)
+	return v.bdnScheme.Verify(point, msg, sig)
+}
+
+func (v *Verifier) BatchVerify(pubKeys []gpbft.PubKey, msgs [][]byte, sigs [][]byte) (_err error) {
+	defer func() {
+		status := measurements.AttrStatusSuccess
+		if _err != nil {
+			status = measurements.AttrStatusError
+		}
+		if perr := recover(); perr != nil {
+			_err = fmt.Errorf("panicked validating batch signature: %v\n%s",
+				perr, string(debug.Stack()))
+			log.Error(_err)
+			status = measurements.AttrStatusPanic
+		}
+		metrics.verify.Add(context.TODO(), 1, metric.WithAttributes(status))
+	}()
+	if len(msgs) != len(sigs) {
+		return fmt.Errorf("number of signatures must match the number of messages")
+	}
+
+	if len(pubKeys) != len(sigs) {
+		return fmt.Errorf("number of public keys must match the number of messages")
+	}
+
+	points := make([]kyber.Point, len(msgs))
+	for i, pubKey := range pubKeys {
+		var err error
+		points[i], err = v.pubkeyToPoint(pubKey)
+		if err != nil {
+			return fmt.Errorf("unarshalling public key: %w", err)
+		}
+	}
+	aggSig, err := v.blsScheme.AggregateSignatures(sigs...)
+	if err != nil {
+		return fmt.Errorf("aggregating signatures: %w", err)
+	}
+
+	return bls.BatchVerify(v.suite, points, msgs, aggSig)
 }