Is slashable block rpc endpoint implementation (#5765)

* is slashable block rpc endpoint implementation

* add span

* raul feedback

* fix error

Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

beacon-chain/core/blocks/block_operations.go

@@ -203,16 +203,16 @@ func ProcessBlockHeader(
 	}
 
 	// Verify proposer signature.
-	if err := VerifyBlockHeaderSignature(beaconState, block); err != nil {
+	if err := VerifyBlockSignature(beaconState, block); err != nil {
 		return nil, err
 	}
 
 	return beaconState, nil
 }
 
-// VerifyBlockHeaderSignature verifies the proposer signature of a beacon block.
-func VerifyBlockHeaderSignature(beaconState *stateTrie.BeaconState, block *ethpb.SignedBeaconBlock) error {
-	proposer, err := beaconState.ValidatorAtIndexReadOnly(block.Block.ProposerIndex)
+// VerifyBlockSignature verifies the proposer signature of a beacon block.
+func VerifyBlockSignature(beaconState *stateTrie.BeaconState, block *ethpb.SignedBeaconBlock) error {
+	proposer, err := beaconState.ValidatorAtIndex(block.Block.ProposerIndex)
 	if err != nil {
 		return err
 	}
@@ -222,7 +222,7 @@ func VerifyBlockHeaderSignature(beaconState *stateTrie.BeaconState, block *ethpb
 	if err != nil {
 		return err
 	}
-	proposerPubKey := proposer.PublicKey()
+	proposerPubKey := proposer.PublicKey
 	return helpers.VerifyBlockSigningRoot(block.Block, proposerPubKey[:], block.Signature, domain)
 }
 

beacon-chain/core/helpers/signing_root.go

@@ -98,6 +98,28 @@ func VerifyBlockSigningRoot(blk *ethpb.BeaconBlock, pub []byte, signature []byte
 	return nil
 }
 
+// VerifyBlockHeaderSigningRoot verifies the signing root of a block header given it's public key, signature and domain.
+func VerifyBlockHeaderSigningRoot(blkHdr *ethpb.BeaconBlockHeader, pub []byte, signature []byte, domain []byte) error {
+	publicKey, err := bls.PublicKeyFromBytes(pub)
+	if err != nil {
+		return errors.Wrap(err, "could not convert bytes to public key")
+	}
+	sig, err := bls.SignatureFromBytes(signature)
+	if err != nil {
+		return errors.Wrap(err, "could not convert bytes to signature")
+	}
+	root, err := signingRoot(func() ([32]byte, error) {
+		return stateutil.BlockHeaderRoot(blkHdr)
+	}, domain)
+	if err != nil {
+		return errors.Wrap(err, "could not compute signing root")
+	}
+	if !sig.Verify(root[:], publicKey) {
+		return ErrSigFailedToVerify
+	}
+	return nil
+}
+
 // ComputeDomain returns the domain version for BLS private key to sign and verify with a zeroed 4-byte
 // array as the fork version.
 //

beacon-chain/sync/validate_beacon_blocks.go

@@ -111,7 +111,7 @@ func (r *Service) validateBeaconBlockPubSub(ctx context.Context, pid peer.ID, ms
 			return false
 		}
 
-		if err := blocks.VerifyBlockHeaderSignature(parentState, blk); err != nil {
+		if err := blocks.VerifyBlockSignature(parentState, blk); err != nil {
 			log.WithError(err).WithField("blockSlot", blk.Block.Slot).Warn("Could not verify block signature")
 			return false
 		}

slasher/beaconclient/chain_data.go

@@ -27,21 +27,25 @@ func (bs *Service) ChainHead(
 	return res, nil
 }
 
-// GenesisValidatorsRoot requests the beacon chain genesis validators
-// root via gRPC.
+// GenesisValidatorsRoot requests or fetch from memory the beacon chain genesis
+// validators root via gRPC.
 func (bs *Service) GenesisValidatorsRoot(
 	ctx context.Context,
 ) ([]byte, error) {
 	ctx, span := trace.StartSpan(ctx, "beaconclient.GenesisValidatorsRoot")
 	defer span.End()
-	res, err := bs.nodeClient.GetGenesis(ctx, &ptypes.Empty{})
-	if err != nil {
-		return nil, errors.Wrap(err, "Could not retrieve genesis data")
-	}
-	if res == nil {
-		return nil, errors.Wrap(err, " genesis data")
+
+	if bs.genesisValidatorRoot == nil {
+		res, err := bs.nodeClient.GetGenesis(ctx, &ptypes.Empty{})
+		if err != nil {
+			return nil, errors.Wrap(err, "could not retrieve genesis data")
+		}
+		if res == nil {
+			return nil, errors.Wrap(err, "nil genesis data")
+		}
+		bs.genesisValidatorRoot = res.GenesisValidatorsRoot
 	}
-	return res.GenesisValidatorsRoot, nil
+	return bs.genesisValidatorRoot, nil
 }
 
 // Poll the beacon node every syncStatusPollingInterval until the node

slasher/beaconclient/chain_data_test.go

@@ -56,6 +56,14 @@ func TestService_GenesisValidatorsRoot(t *testing.T) {
 	if !bytes.Equal(res, wanted.GenesisValidatorsRoot) {
 		t.Errorf("Wanted %#x, received %#x", wanted.GenesisValidatorsRoot, res)
 	}
+	// test next fetch uses memory and not the rpc call.
+	res, err = bs.GenesisValidatorsRoot(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(res, wanted.GenesisValidatorsRoot) {
+		t.Errorf("Wanted %#x, received %#x", wanted.GenesisValidatorsRoot, res)
+	}
 }
 
 func TestService_QuerySyncStatus(t *testing.T) {

slasher/beaconclient/service.go

@@ -58,6 +58,7 @@ type Service struct {
 	receivedAttestationsBuffer  chan *ethpb.IndexedAttestation
 	collectedAttestationsBuffer chan []*ethpb.IndexedAttestation
 	publicKeyCache              *cache.PublicKeyCache
+	genesisValidatorRoot        []byte
 }
 
 // Config options for the beaconclient service.

slasher/detection/proposals/detector.go

@@ -46,5 +46,8 @@ func (dd *ProposeDetector) DetectDoublePropose(
 		}
 		return ps, nil
 	}
+	if err := dd.slasherDB.SaveBlockHeader(ctx, incomingBlk); err != nil {
+		return nil, err
+	}
 	return nil, nil
 }

slasher/rpc/BUILD.bazel

@@ -70,7 +70,9 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/state/stateutil:go_default_library",
         "//shared/bls:go_default_library",
+        "//shared/bytesutil:go_default_library",
         "//shared/mock:go_default_library",
         "//shared/p2putils:go_default_library",
         "//shared/params:go_default_library",

slasher/rpc/server.go

@@ -34,6 +34,23 @@ type Server struct {
 func (ss *Server) IsSlashableAttestation(ctx context.Context, req *ethpb.IndexedAttestation) (*slashpb.AttesterSlashingResponse, error) {
 	ctx, span := trace.StartSpan(ctx, "detection.IsSlashableAttestation")
 	defer span.End()
+
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "nil request provided")
+	}
+	if req.Data == nil {
+		return nil, status.Error(codes.InvalidArgument, "nil request data provided")
+	}
+	if req.Data.Target == nil {
+		return nil, status.Error(codes.InvalidArgument, "nil request data target provided")
+	}
+	if req.Data.Source == nil {
+		return nil, status.Error(codes.InvalidArgument, "nil request data source provided")
+	}
+	if req.Signature == nil {
+		return nil, status.Error(codes.InvalidArgument, "nil signature provided")
+	}
+
 	err := attestationutil.IsValidAttestationIndices(ctx, req)
 	if err != nil {
 		return nil, err
@@ -91,5 +108,47 @@ func (ss *Server) IsSlashableAttestation(ctx context.Context, req *ethpb.Indexed
 // IsSlashableBlock returns an proposer slashing if the block submitted
 // is a double proposal.
 func (ss *Server) IsSlashableBlock(ctx context.Context, req *ethpb.SignedBeaconBlockHeader) (*slashpb.ProposerSlashingResponse, error) {
-	return nil, errors.New("unimplemented")
+	ctx, span := trace.StartSpan(ctx, "detection.IsSlashableBlock")
+	defer span.End()
+
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "nil request provided")
+	}
+	if req.Header == nil {
+		return nil, status.Error(codes.InvalidArgument, "nil header provided")
+
+	}
+	if req.Signature == nil {
+		return nil, status.Error(codes.InvalidArgument, "nil signature provided")
+	}
+	gvr, err := ss.beaconClient.GenesisValidatorsRoot(ctx)
+	if err != nil {
+		return nil, err
+	}
+	blockEpoch := helpers.SlotToEpoch(req.Header.Slot)
+	fork, err := p2putils.Fork(blockEpoch)
+	if err != nil {
+		return nil, err
+	}
+	domain, err := helpers.Domain(fork, blockEpoch, params.BeaconConfig().DomainBeaconProposer, gvr)
+	if err != nil {
+		return nil, err
+	}
+	pkMap, err := ss.beaconClient.FindOrGetPublicKeys(ctx, []uint64{req.Header.ProposerIndex})
+	if err := helpers.VerifyBlockHeaderSigningRoot(
+		req.Header, pkMap[req.Header.ProposerIndex], req.Signature, domain); err != nil {
+		return nil, err
+	}
+	slashing, err := ss.detector.DetectDoubleProposals(ctx, req)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "Could not detect proposer slashing for block: %v: %v", req, err)
+	}
+	psr := &slashpb.ProposerSlashingResponse{}
+	if slashing != nil {
+		psr = &slashpb.ProposerSlashingResponse{
+			ProposerSlashing: []*ethpb.ProposerSlashing{slashing},
+		}
+	}
+	return psr, nil
+
 }

slasher/rpc/server_test.go

@@ -7,7 +7,9 @@ import (
 	"github.com/golang/mock/gomock"
 	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stateutil"
 	"github.com/prysmaticlabs/prysm/shared/bls"
+	"github.com/prysmaticlabs/prysm/shared/bytesutil"
 	"github.com/prysmaticlabs/prysm/shared/mock"
 	"github.com/prysmaticlabs/prysm/shared/p2putils"
 	"github.com/prysmaticlabs/prysm/shared/params"
@@ -17,7 +19,7 @@ import (
 	"github.com/prysmaticlabs/prysm/slasher/detection"
 )
 
-func Test_DetectionFlow(t *testing.T) {
+func TestServer_IsSlashableAttestation(t *testing.T) {
 	db := testDB.SetupSlasherDB(t, false)
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()
@@ -94,7 +96,7 @@ func Test_DetectionFlow(t *testing.T) {
 
 	incomingAtt.Signature = marshalledSig
 
-	domain, err = helpers.Domain(fork, incomingAtt.Data.Target.Epoch, params.BeaconConfig().DomainBeaconAttester, wantedGenesis.GenesisValidatorsRoot)
+	domain, err = helpers.Domain(fork, savedAttestation.Data.Target.Epoch, params.BeaconConfig().DomainBeaconAttester, wantedGenesis.GenesisValidatorsRoot)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -127,7 +129,6 @@ func Test_DetectionFlow(t *testing.T) {
 		gomock.Any(),
 		gomock.Any(),
 	).Return(wantedValidators2, nil)
-	nClient.EXPECT().GetGenesis(gomock.Any(), gomock.Any()).Return(wantedGenesis, nil)
 	slashing, err := server.IsSlashableAttestation(ctx, incomingAtt)
 	if err != nil {
 		t.Fatalf("got error while trying to detect slashing: %v", err)
@@ -136,3 +137,105 @@ func Test_DetectionFlow(t *testing.T) {
 		t.Fatalf("only one slashing should have been found. got: %v", len(slashing.AttesterSlashing))
 	}
 }
+
+func TestServer_IsSlashableBlock(t *testing.T) {
+	db := testDB.SetupSlasherDB(t, false)
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	bClient := mock.NewMockBeaconChainClient(ctrl)
+	nClient := mock.NewMockNodeClient(ctrl)
+	ctx := context.Background()
+
+	_, keys, err := testutil.DeterministicDepositsAndKeys(4)
+	if err != nil {
+		t.Fatal(err)
+	}
+	wantedValidators := &ethpb.Validators{
+		ValidatorList: []*ethpb.Validators_ValidatorContainer{
+			{
+				Index: 1, Validator: &ethpb.Validator{PublicKey: keys[1].PublicKey().Marshal()},
+			},
+		},
+	}
+	bClient.EXPECT().ListValidators(
+		gomock.Any(),
+		gomock.Any(),
+	).Return(wantedValidators, nil)
+
+	wantedGenesis := &ethpb.Genesis{
+		GenesisValidatorsRoot: []byte("I am genesis"),
+	}
+	nClient.EXPECT().GetGenesis(gomock.Any(), gomock.Any()).Return(wantedGenesis, nil)
+	savedBlock := &ethpb.SignedBeaconBlockHeader{
+		Header: &ethpb.BeaconBlockHeader{
+			Slot:          1,
+			ProposerIndex: 1,
+			BodyRoot:      bytesutil.PadTo([]byte("body root"), 32),
+		},
+	}
+	incomingBlock := &ethpb.SignedBeaconBlockHeader{
+		Header: &ethpb.BeaconBlockHeader{
+			Slot:          1,
+			ProposerIndex: 1,
+			BodyRoot:      bytesutil.PadTo([]byte("body root2"), 32),
+		},
+	}
+	cfg := &detection.Config{
+		SlasherDB: db,
+	}
+	incomingBlockEpoch := helpers.SlotToEpoch(incomingBlock.Header.Slot)
+	fork, err := p2putils.Fork(incomingBlockEpoch)
+	if err != nil {
+		t.Fatal(err)
+	}
+	domain, err := helpers.Domain(fork, incomingBlockEpoch, params.BeaconConfig().DomainBeaconProposer, wantedGenesis.GenesisValidatorsRoot)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bhr, err := stateutil.BlockHeaderRoot(incomingBlock.Header)
+	if err != nil {
+		t.Error(err)
+	}
+	root, err := helpers.ComputeSigningRoot(bhr, domain)
+	if err != nil {
+		t.Error(err)
+	}
+	blockSig := keys[incomingBlock.Header.ProposerIndex].Sign(root[:])
+	marshalledSig := blockSig.Marshal()
+	incomingBlock.Signature = marshalledSig
+
+	savedBlockEpoch := helpers.SlotToEpoch(savedBlock.Header.Slot)
+	domain, err = helpers.Domain(fork, savedBlockEpoch, params.BeaconConfig().DomainBeaconProposer, wantedGenesis.GenesisValidatorsRoot)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bhr, err = stateutil.BlockHeaderRoot(savedBlock.Header)
+	if err != nil {
+		t.Error(err)
+	}
+	root, err = helpers.ComputeSigningRoot(bhr, domain)
+	if err != nil {
+		t.Error(err)
+	}
+	blockSig = keys[savedBlock.Header.ProposerIndex].Sign(root[:])
+	marshalledSig = blockSig.Marshal()
+	savedBlock.Signature = marshalledSig
+	bcCfg := &beaconclient.Config{BeaconClient: bClient, NodeClient: nClient, SlasherDB: db}
+	bs, err := beaconclient.NewBeaconClientService(ctx, bcCfg)
+	ds := detection.NewDetectionService(ctx, cfg)
+	server := Server{ctx: ctx, detector: ds, slasherDB: db, beaconClient: bs}
+	slashings, err := server.IsSlashableBlock(ctx, savedBlock)
+	if err != nil {
+		t.Fatalf("got error while trying to detect slashing: %v", err)
+	}
+	if len(slashings.ProposerSlashing) != 0 {
+		t.Fatalf("Found slashings while no slashing should have been found on first block: %v slashing found: %v", savedBlock, slashings)
+	}
+	slashing, err := server.IsSlashableBlock(ctx, incomingBlock)
+	if err != nil {
+		t.Fatalf("got error while trying to detect slashing: %v", err)
+	}
+	if len(slashing.ProposerSlashing) != 1 {
+		t.Fatalf("only one slashing should have been found. got: %v", len(slashing.ProposerSlashing))
+	}
+}