fix up faulty slasher ticker

* Move necessary functions beacon-chain/core/time -> time/slots

* Fix fuzz

* Fix build

* Update slot_epoch.go

.buildkite-bazelrc

@@ -10,7 +10,7 @@
 
 # Prysm specific remote-cache properties.
 #build:remote-cache --disk_cache=
-build:remote-cache --remote_download_minimal
+build:remote-cache --remote_download_toplevel
 build:remote-cache --remote_cache=grpc://bazel-remote-cache:9092
 build:remote-cache --experimental_remote_downloader=grpc://bazel-remote-cache:9092
 build:remote-cache --remote_local_fallback
@@ -46,4 +46,4 @@ test:fuzz --flaky_test_attempts=1
 
 # Better caching
 build:nostamp --nostamp
-build:nostamp --workspace_status_command=./hack/workspace_status_ci.sh
+build:nostamp --workspace_status_command=./hack/workspace_status_ci.sh

WORKSPACE

@@ -197,7 +197,7 @@ filegroup(
     url = "https://github.com/eth2-clients/slashing-protection-interchange-tests/archive/b8413ca42dc92308019d0d4db52c87e9e125c4e9.tar.gz",
 )
 
-consensus_spec_version = "v1.1.0-beta.4"
+consensus_spec_version = "v1.1.0"
 
 bls_test_version = "v0.1.1"
 
@@ -213,7 +213,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    sha256 = "d2d501453cf29777896a5f9ae52e93921f34330e57fcc5b55e4982d4795236b9",
+    sha256 = "0f58ec1c8995ab2c0a3aada873e1a02f333c8659fdacaa1c76fbdce28b6177dc",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )
 
@@ -229,7 +229,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    sha256 = "b152f1f03a4fdacd1882fe867bdfbd5067e74ed3c532bd01d81e7adf6cc3737a",
+    sha256 = "d2eeadef3f8885748f769a06eb916bea60fb00112a90cec3288ea78db5557df3",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )
 
@@ -245,7 +245,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    sha256 = "6046f89c679a9ffda217dee6f021eb7c4fe91aad6ff940fae4d2cf894cc61cbb",
+    sha256 = "bbc345432f4eaa4babe2619e16fcf3f607113ede82d1bd0fff2633c1376419f7",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )
 
@@ -260,7 +260,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    sha256 = "26a0a2c3022a3c5354f3204c7e441580df2e585dbde22a43a1d43f885b3a221c",
+    sha256 = "787a50c2a03bebab92f089333f598780ca7b4849b36a4897e6603ddd3e86ec24",
     strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
     url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )

api/gateway/apimiddleware/api_middleware.go

@@ -59,8 +59,8 @@ type CustomHandler = func(m *ApiProxyMiddleware, endpoint Endpoint, w http.Respo
 
 // HookCollection contains hooks that can be used to amend the default request/response cycle with custom logic for a specific endpoint.
 type HookCollection struct {
-	OnPreDeserializeRequestBodyIntoContainer      func(endpoint Endpoint, w http.ResponseWriter, req *http.Request) (RunDefault, ErrorJson)
-	OnPostDeserializeRequestBodyIntoContainer     func(endpoint Endpoint, w http.ResponseWriter, req *http.Request) ErrorJson
+	OnPreDeserializeRequestBodyIntoContainer      func(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) (RunDefault, ErrorJson)
+	OnPostDeserializeRequestBodyIntoContainer     func(endpoint *Endpoint, w http.ResponseWriter, req *http.Request) ErrorJson
 	OnPreDeserializeGrpcResponseBodyIntoContainer func([]byte, interface{}) (RunDefault, ErrorJson)
 	OnPreSerializeMiddlewareResponseIntoJson      func(interface{}) (RunDefault, []byte, ErrorJson)
 }
@@ -170,7 +170,7 @@ func (m *ApiProxyMiddleware) handleApiPath(gatewayRouter *mux.Router, path strin
 func deserializeRequestBodyIntoContainerWrapped(endpoint *Endpoint, req *http.Request, w http.ResponseWriter) ErrorJson {
 	runDefault := true
 	if endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer != nil {
-		run, errJson := endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer(*endpoint, w, req)
+		run, errJson := endpoint.Hooks.OnPreDeserializeRequestBodyIntoContainer(endpoint, w, req)
 		if errJson != nil {
 			return errJson
 		}
@@ -184,7 +184,7 @@ func deserializeRequestBodyIntoContainerWrapped(endpoint *Endpoint, req *http.Re
 		}
 	}
 	if endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer != nil {
-		if errJson := endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer(*endpoint, w, req); errJson != nil {
+		if errJson := endpoint.Hooks.OnPostDeserializeRequestBodyIntoContainer(endpoint, w, req); errJson != nil {
 			return errJson
 		}
 	}

api/gateway/apimiddleware/process_request.go

@@ -10,12 +10,22 @@ import (
 	"strings"
 	"time"
 
+	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/api/grpc"
 )
 
 // DeserializeRequestBodyIntoContainer deserializes the request's body into an endpoint-specific struct.
 func DeserializeRequestBodyIntoContainer(body io.Reader, requestContainer interface{}) ErrorJson {
-	if err := json.NewDecoder(body).Decode(&requestContainer); err != nil {
+	decoder := json.NewDecoder(body)
+	decoder.DisallowUnknownFields()
+	if err := decoder.Decode(&requestContainer); err != nil {
+		if strings.Contains(err.Error(), "json: unknown field") {
+			e := errors.Wrap(err, "could not decode request body")
+			return &DefaultErrorJson{
+				Message: e.Error(),
+				Code:    http.StatusBadRequest,
+			}
+		}
 		return InternalServerErrorWithMessage(err, "could not decode request body")
 	}
 	return nil

api/gateway/apimiddleware/process_request_test.go

@@ -83,6 +83,15 @@ func TestDeserializeRequestBodyIntoContainer(t *testing.T) {
 		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not decode request body"))
 		assert.Equal(t, http.StatusInternalServerError, errJson.StatusCode())
 	})
+
+	t.Run("unknown field", func(t *testing.T) {
+		var bodyJson bytes.Buffer
+		bodyJson.Write([]byte("{\"foo\":\"foo\"}"))
+		errJson := DeserializeRequestBodyIntoContainer(&bodyJson, &testRequestContainer{})
+		require.NotNil(t, errJson)
+		assert.Equal(t, true, strings.Contains(errJson.Msg(), "could not decode request body"))
+		assert.Equal(t, http.StatusBadRequest, errJson.StatusCode())
+	})
 }
 
 func TestProcessRequestContainerFields(t *testing.T) {

beacon-chain/blockchain/BUILD.bazel

@@ -23,17 +23,20 @@ go_library(
     visibility = [
         "//beacon-chain:__subpackages__",
         "//testing/fuzz:__pkg__",
+        "//testing/slasher/simulator:__pkg__",
     ],
     deps = [
         "//async:go_default_library",
+        "//async/event:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositcache:go_default_library",
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/epoch/precompute:go_default_library",
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filters:go_default_library",

beacon-chain/blockchain/chain_info.go

@@ -182,7 +182,7 @@ func (s *Service) HeadValidatorsIndices(ctx context.Context, epoch types.Epoch)
 	if !s.hasHeadState() {
 		return []types.ValidatorIndex{}, nil
 	}
-	return helpers.ActiveValidatorIndices(s.headState(ctx), epoch)
+	return helpers.ActiveValidatorIndices(ctx, s.headState(ctx), epoch)
 }
 
 // HeadSeed returns the seed from the head view of a given epoch.
@@ -293,7 +293,9 @@ func (s *Service) ChainHeads() ([][32]byte, []types.Slot) {
 func (s *Service) HeadPublicKeyToValidatorIndex(ctx context.Context, pubKey [48]byte) (types.ValidatorIndex, bool) {
 	s.headLock.RLock()
 	defer s.headLock.RUnlock()
-
+	if !s.hasHeadState() {
+		return 0, false
+	}
 	return s.headState(ctx).ValidatorIndexByPubkey(pubKey)
 }
 
@@ -301,7 +303,9 @@ func (s *Service) HeadPublicKeyToValidatorIndex(ctx context.Context, pubKey [48]
 func (s *Service) HeadValidatorIndexToPublicKey(_ context.Context, index types.ValidatorIndex) ([48]byte, error) {
 	s.headLock.RLock()
 	defer s.headLock.RUnlock()
-
+	if !s.hasHeadState() {
+		return [48]byte{}, nil
+	}
 	v, err := s.headValidatorAtIndex(index)
 	if err != nil {
 		return [48]byte{}, err

beacon-chain/blockchain/chain_info_test.go

@@ -313,6 +313,20 @@ func TestService_HeadPublicKeyToValidatorIndex(t *testing.T) {
 	require.Equal(t, types.ValidatorIndex(0), i)
 }
 
+func TestService_HeadPublicKeyToValidatorIndexNil(t *testing.T) {
+	c := &Service{}
+	c.head = nil
+
+	idx, e := c.HeadPublicKeyToValidatorIndex(context.Background(), [48]byte{})
+	require.Equal(t, false, e)
+	require.Equal(t, types.ValidatorIndex(0), idx)
+
+	c.head = &head{state: nil}
+	i, e := c.HeadPublicKeyToValidatorIndex(context.Background(), [48]byte{})
+	require.Equal(t, false, e)
+	require.Equal(t, types.ValidatorIndex(0), i)
+}
+
 func TestService_HeadValidatorIndexToPublicKey(t *testing.T) {
 	s, _ := util.DeterministicGenesisState(t, 10)
 	c := &Service{}
@@ -326,3 +340,17 @@ func TestService_HeadValidatorIndexToPublicKey(t *testing.T) {
 
 	require.Equal(t, bytesutil.ToBytes48(v.PublicKey), p)
 }
+
+func TestService_HeadValidatorIndexToPublicKeyNil(t *testing.T) {
+	c := &Service{}
+	c.head = nil
+
+	p, err := c.HeadValidatorIndexToPublicKey(context.Background(), 0)
+	require.NoError(t, err)
+	require.Equal(t, [48]byte{}, p)
+
+	c.head = &head{state: nil}
+	p, err = c.HeadValidatorIndexToPublicKey(context.Background(), 0)
+	require.NoError(t, err)
+	require.Equal(t, [48]byte{}, p)
+}

beacon-chain/blockchain/head.go

@@ -7,10 +7,10 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/features"
@@ -141,7 +141,7 @@ func (s *Service) saveHead(ctx context.Context, headRoot [32]byte) error {
 				NewHeadBlock: headRoot[:],
 				OldHeadState: oldStateRoot,
 				NewHeadState: newStateRoot,
-				Epoch:        core.SlotToEpoch(newHeadSlot),
+				Epoch:        slots.ToEpoch(newHeadSlot),
 			},
 		})
 
@@ -298,7 +298,7 @@ func (s *Service) cacheJustifiedStateBalances(ctx context.Context, justifiedRoot
 		return errors.New("justified state can't be nil")
 	}
 
-	epoch := core.CurrentEpoch(justifiedState)
+	epoch := time.CurrentEpoch(justifiedState)
 
 	justifiedBalances := make([]uint64, justifiedState.NumValidators())
 	if err := justifiedState.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
@@ -336,15 +336,15 @@ func (s *Service) notifyNewHeadEvent(
 	currentDutyDependentRoot := s.genesisRoot[:]
 
 	var previousDutyEpoch types.Epoch
-	currentDutyEpoch := core.SlotToEpoch(newHeadSlot)
+	currentDutyEpoch := slots.ToEpoch(newHeadSlot)
 	if currentDutyEpoch > 0 {
 		previousDutyEpoch = currentDutyEpoch.Sub(1)
 	}
-	currentDutySlot, err := core.StartSlot(currentDutyEpoch)
+	currentDutySlot, err := slots.EpochStart(currentDutyEpoch)
 	if err != nil {
 		return errors.Wrap(err, "could not get duty slot")
 	}
-	previousDutySlot, err := core.StartSlot(previousDutyEpoch)
+	previousDutySlot, err := slots.EpochStart(previousDutyEpoch)
 	if err != nil {
 		return errors.Wrap(err, "could not get duty slot")
 	}
@@ -366,7 +366,7 @@ func (s *Service) notifyNewHeadEvent(
 			Slot:                      newHeadSlot,
 			Block:                     newHeadRoot,
 			State:                     newHeadStateRoot,
-			EpochTransition:           core.IsEpochEnd(newHeadSlot),
+			EpochTransition:           slots.IsEpochStart(newHeadSlot),
 			PreviousDutyDependentRoot: previousDutyDependentRoot,
 			CurrentDutyDependentRoot:  currentDutyDependentRoot,
 		},

beacon-chain/blockchain/head_sync_committee_info.go

@@ -8,13 +8,14 @@ import (
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/async"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // Initialize the state cache for sync committees.
@@ -61,14 +62,14 @@ func (s *Service) HeadSyncContributionProofDomain(ctx context.Context, slot type
 // rather than for the range
 // [compute_start_slot_at_epoch(epoch), compute_start_slot_at_epoch(epoch) + SLOTS_PER_EPOCH)
 func (s *Service) HeadSyncCommitteeIndices(ctx context.Context, index types.ValidatorIndex, slot types.Slot) ([]types.CommitteeIndex, error) {
-	nextSlotEpoch := core.SlotToEpoch(slot + 1)
-	currentEpoch := core.SlotToEpoch(slot)
+	nextSlotEpoch := slots.ToEpoch(slot + 1)
+	currentEpoch := slots.ToEpoch(slot)
 
 	switch {
-	case core.SyncCommitteePeriod(nextSlotEpoch) == core.SyncCommitteePeriod(currentEpoch):
+	case slots.SyncCommitteePeriod(nextSlotEpoch) == slots.SyncCommitteePeriod(currentEpoch):
 		return s.headCurrentSyncCommitteeIndices(ctx, index, slot)
 	// At sync committee period boundary, validator should sample the next epoch sync committee.
-	case core.SyncCommitteePeriod(nextSlotEpoch) == core.SyncCommitteePeriod(currentEpoch)+1:
+	case slots.SyncCommitteePeriod(nextSlotEpoch) == slots.SyncCommitteePeriod(currentEpoch)+1:
 		return s.headNextSyncCommitteeIndices(ctx, index, slot)
 	default:
 		// Impossible condition.
@@ -104,11 +105,11 @@ func (s *Service) HeadSyncCommitteePubKeys(ctx context.Context, slot types.Slot,
 		return nil, err
 	}
 
-	nextSlotEpoch := core.SlotToEpoch(headState.Slot() + 1)
-	currEpoch := core.SlotToEpoch(headState.Slot())
+	nextSlotEpoch := slots.ToEpoch(headState.Slot() + 1)
+	currEpoch := slots.ToEpoch(headState.Slot())
 
 	var syncCommittee *ethpb.SyncCommittee
-	if currEpoch == nextSlotEpoch || core.SyncCommitteePeriod(currEpoch) == core.SyncCommitteePeriod(nextSlotEpoch) {
+	if currEpoch == nextSlotEpoch || slots.SyncCommitteePeriod(currEpoch) == slots.SyncCommitteePeriod(nextSlotEpoch) {
 		syncCommittee, err = headState.CurrentSyncCommittee()
 		if err != nil {
 			return nil, err
@@ -129,7 +130,7 @@ func (s *Service) domainWithHeadState(ctx context.Context, slot types.Slot, doma
 	if err != nil {
 		return nil, err
 	}
-	return helpers.Domain(headState.Fork(), core.SlotToEpoch(headState.Slot()), domain, headState.GenesisValidatorRoot())
+	return signing.Domain(headState.Fork(), slots.ToEpoch(headState.Slot()), domain, headState.GenesisValidatorRoot())
 }
 
 // returns the head state that is advanced up to `slot`. It utilizes the cache `syncCommitteeHeadState` by retrieving using `slot` as key.

beacon-chain/blockchain/head_sync_committee_info_test.go

@@ -6,13 +6,13 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	dbtest "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 func TestService_headSyncCommitteeFetcher_Errors(t *testing.T) {
@@ -122,7 +122,7 @@ func TestService_HeadSyncCommitteeDomain(t *testing.T) {
 	c := &Service{}
 	c.head = &head{state: s}
 
-	wanted, err := helpers.Domain(s.Fork(), core.SlotToEpoch(s.Slot()), params.BeaconConfig().DomainSyncCommittee, s.GenesisValidatorRoot())
+	wanted, err := signing.Domain(s.Fork(), slots.ToEpoch(s.Slot()), params.BeaconConfig().DomainSyncCommittee, s.GenesisValidatorRoot())
 	require.NoError(t, err)
 
 	d, err := c.HeadSyncCommitteeDomain(context.Background(), 0)
@@ -136,7 +136,7 @@ func TestService_HeadSyncContributionProofDomain(t *testing.T) {
 	c := &Service{}
 	c.head = &head{state: s}
 
-	wanted, err := helpers.Domain(s.Fork(), core.SlotToEpoch(s.Slot()), params.BeaconConfig().DomainContributionAndProof, s.GenesisValidatorRoot())
+	wanted, err := signing.Domain(s.Fork(), slots.ToEpoch(s.Slot()), params.BeaconConfig().DomainContributionAndProof, s.GenesisValidatorRoot())
 	require.NoError(t, err)
 
 	d, err := c.HeadSyncContributionProofDomain(context.Background(), 0)
@@ -150,7 +150,7 @@ func TestService_HeadSyncSelectionProofDomain(t *testing.T) {
 	c := &Service{}
 	c.head = &head{state: s}
 
-	wanted, err := helpers.Domain(s.Fork(), core.SlotToEpoch(s.Slot()), params.BeaconConfig().DomainSyncCommitteeSelectionProof, s.GenesisValidatorRoot())
+	wanted, err := signing.Domain(s.Fork(), slots.ToEpoch(s.Slot()), params.BeaconConfig().DomainSyncCommitteeSelectionProof, s.GenesisValidatorRoot())
 	require.NoError(t, err)
 
 	d, err := c.HeadSyncSelectionProofDomain(context.Background(), 0)

beacon-chain/blockchain/head_test.go

@@ -8,7 +8,6 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	mock "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
 	"github.com/prysmaticlabs/prysm/config/features"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -18,6 +17,7 @@ import (
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )
 
@@ -187,9 +187,9 @@ func Test_notifyNewHeadEvent(t *testing.T) {
 			},
 			genesisRoot: genesisRoot,
 		}
-		epoch1Start, err := core.StartSlot(1)
+		epoch1Start, err := slots.EpochStart(1)
 		require.NoError(t, err)
-		epoch2Start, err := core.StartSlot(1)
+		epoch2Start, err := slots.EpochStart(1)
 		require.NoError(t, err)
 		require.NoError(t, bState.SetSlot(epoch1Start))
 
@@ -206,7 +206,7 @@ func Test_notifyNewHeadEvent(t *testing.T) {
 			Slot:                      epoch2Start,
 			Block:                     newHeadRoot[:],
 			State:                     newHeadStateRoot[:],
-			EpochTransition:           false,
+			EpochTransition:           true,
 			PreviousDutyDependentRoot: genesisRoot[:],
 			CurrentDutyDependentRoot:  make([]byte, 32),
 		}

beacon-chain/blockchain/log.go

@@ -5,12 +5,12 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/config/params"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/block"
 	"github.com/prysmaticlabs/prysm/runtime/version"
 	prysmTime "github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"github.com/sirupsen/logrus"
 )
 
@@ -44,7 +44,7 @@ func logStateTransitionData(b block.BeaconBlock) {
 }
 
 func logBlockSyncStatus(block block.BeaconBlock, blockRoot [32]byte, finalized *ethpb.Checkpoint, receivedTime time.Time, genesisTime uint64) error {
-	startTime, err := core.SlotToTime(genesisTime, block.Slot())
+	startTime, err := slots.ToTime(genesisTime, block.Slot())
 	if err != nil {
 		return err
 	}
@@ -52,7 +52,7 @@ func logBlockSyncStatus(block block.BeaconBlock, blockRoot [32]byte, finalized *
 		"slot":           block.Slot(),
 		"slotInEpoch":    block.Slot() % params.BeaconConfig().SlotsPerEpoch,
 		"block":          fmt.Sprintf("0x%s...", hex.EncodeToString(blockRoot[:])[:8]),
-		"epoch":          core.SlotToEpoch(block.Slot()),
+		"epoch":          slots.ToEpoch(block.Slot()),
 		"finalizedEpoch": finalized.Epoch,
 		"finalizedRoot":  fmt.Sprintf("0x%s...", hex.EncodeToString(finalized.Root)[:8]),
 	}).Info("Synced new block")

beacon-chain/blockchain/process_attestation.go

@@ -4,13 +4,13 @@ import (
 	"context"
 
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )
 
@@ -75,12 +75,12 @@ func (s *Service) onAttestation(ctx context.Context, a *ethpb.Attestation) error
 	// validate_aggregate_proof.go and validate_beacon_attestation.go
 
 	// Verify attestations can only affect the fork choice of subsequent slots.
-	if err := core.VerifySlotTime(genesisTime, a.Data.Slot+1, params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
+	if err := slots.VerifyTime(genesisTime, a.Data.Slot+1, params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
 		return err
 	}
 
 	// Use the target state to verify attesting indices are valid.
-	committee, err := helpers.BeaconCommitteeFromState(baseState, a.Data.Slot, a.Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(ctx, baseState, a.Data.Slot, a.Data.CommitteeIndex)
 	if err != nil {
 		return err
 	}

beacon-chain/blockchain/process_attestation_helpers.go

@@ -8,13 +8,13 @@ import (
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/async"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // getAttPreState retrieves the att pre state by either from the cache or the DB.
@@ -38,7 +38,7 @@ func (s *Service) getAttPreState(ctx context.Context, c *ethpb.Checkpoint) (stat
 		return nil, errors.Wrapf(err, "could not get pre state for epoch %d", c.Epoch)
 	}
 
-	epochStartSlot, err := core.StartSlot(c.Epoch)
+	epochStartSlot, err := slots.EpochStart(c.Epoch)
 	if err != nil {
 		return nil, err
 	}
@@ -63,7 +63,7 @@ func (s *Service) getAttPreState(ctx context.Context, c *ethpb.Checkpoint) (stat
 // verifyAttTargetEpoch validates attestation is from the current or previous epoch.
 func (s *Service) verifyAttTargetEpoch(_ context.Context, genesisTime, nowTime uint64, c *ethpb.Checkpoint) error {
 	currentSlot := types.Slot((nowTime - genesisTime) / params.BeaconConfig().SecondsPerSlot)
-	currentEpoch := core.SlotToEpoch(currentSlot)
+	currentEpoch := slots.ToEpoch(currentSlot)
 	var prevEpoch types.Epoch
 	// Prevents previous epoch under flow
 	if currentEpoch > 1 {

beacon-chain/blockchain/process_attestation_test.go

@@ -5,7 +5,6 @@ import (
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
 	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
@@ -18,6 +17,7 @@ import (
 	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/prysmaticlabs/prysm/testing/util"
 	"github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
@@ -251,7 +251,7 @@ func TestStore_UpdateCheckpointState(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, baseState, bytesutil.ToBytes32(newCheckpoint.Root)))
 	returned, err = service.getAttPreState(ctx, newCheckpoint)
 	require.NoError(t, err)
-	s, err := core.StartSlot(newCheckpoint.Epoch)
+	s, err := slots.EpochStart(newCheckpoint.Epoch)
 	require.NoError(t, err)
 	baseState, err = transition.ProcessSlots(ctx, baseState, s)
 	require.NoError(t, err)

beacon-chain/blockchain/process_block.go

@@ -6,20 +6,22 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	coreTime "github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/features"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/monitoring/tracing"
 	ethpbv1 "github.com/prysmaticlabs/prysm/proto/eth/v1"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/block"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )
 
@@ -106,22 +108,36 @@ func (s *Service) onBlock(ctx context.Context, signed block.SignedBeaconBlock, b
 		return err
 	}
 
-	// Updating next slot state cache can happen in the background. It shouldn't block rest of the process.
-	if features.Get().EnableNextSlotStateCache {
+	// If slasher is configured, forward the attestations in the block via
+	// an event feed for processing.
+	if features.Get().EnableSlasher {
+		// Feed the indexed attestation to slasher if enabled. This action
+		// is done in the background to avoid adding more load to this critical code path.
 		go func() {
-			// Use a custom deadline here, since this method runs asynchronously.
-			// We ignore the parent method's context and instead create a new one
-			// with a custom deadline, therefore using the background context instead.
-			slotCtx, cancel := context.WithTimeout(context.Background(), slotDeadline)
-			defer cancel()
-			if err := transition.UpdateNextSlotCache(slotCtx, blockRoot[:], postState); err != nil {
-				log.WithError(err).Debug("could not update next slot state cache")
+			// Using a different context to prevent timeouts as this operation can be expensive
+			// and we want to avoid affecting the critical code path.
+			ctx := context.TODO()
+			for _, att := range signed.Block().Body().Attestations() {
+				committee, err := helpers.BeaconCommitteeFromState(ctx, preState, att.Data.Slot, att.Data.CommitteeIndex)
+				if err != nil {
+					log.WithError(err).Error("Could not get attestation committee")
+					tracing.AnnotateError(span, err)
+					return
+				}
+				indexedAtt, err := attestation.ConvertToIndexed(ctx, att, committee)
+				if err != nil {
+					log.WithError(err).Error("Could not convert to indexed attestation")
+					tracing.AnnotateError(span, err)
+					return
+				}
+				s.cfg.SlasherAttestationsFeed.Send(indexedAtt)
 			}
 		}()
 	}
 
 	// Update justified check point.
-	if postState.CurrentJustifiedCheckpoint().Epoch > s.justifiedCheckpt.Epoch {
+	currJustifiedEpoch := s.justifiedCheckpt.Epoch
+	if postState.CurrentJustifiedCheckpoint().Epoch > currJustifiedEpoch {
 		if err := s.updateJustified(ctx, postState); err != nil {
 			return err
 		}
@@ -155,6 +171,27 @@ func (s *Service) onBlock(ctx context.Context, signed block.SignedBeaconBlock, b
 		},
 	})
 
+	// Updating next slot state cache can happen in the background. It shouldn't block rest of the process.
+	if features.Get().EnableNextSlotStateCache {
+		go func() {
+			// Use a custom deadline here, since this method runs asynchronously.
+			// We ignore the parent method's context and instead create a new one
+			// with a custom deadline, therefore using the background context instead.
+			slotCtx, cancel := context.WithTimeout(context.Background(), slotDeadline)
+			defer cancel()
+			if err := transition.UpdateNextSlotCache(slotCtx, blockRoot[:], postState); err != nil {
+				log.WithError(err).Debug("could not update next slot state cache")
+			}
+		}()
+	}
+
+	// Save justified check point to db.
+	if postState.CurrentJustifiedCheckpoint().Epoch > currJustifiedEpoch {
+		if err := s.cfg.BeaconDB.SaveJustifiedCheckpoint(ctx, postState.CurrentJustifiedCheckpoint()); err != nil {
+			return err
+		}
+	}
+
 	// Update finalized check point.
 	if newFinalized {
 		if err := s.updateFinalized(ctx, postState.FinalizedCheckpoint()); err != nil {
@@ -232,7 +269,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []block.SignedBeaconBlo
 			return nil, nil, err
 		}
 		// Save potential boundary states.
-		if core.IsEpochStart(preState.Slot()) {
+		if slots.IsEpochStart(preState.Slot()) {
 			boundaries[blockRoots[i]] = preState.Copy()
 			if err := s.handleEpochBoundary(ctx, preState); err != nil {
 				return nil, nil, errors.Wrap(err, "could not handle epoch boundary state")
@@ -315,7 +352,7 @@ func (s *Service) handleEpochBoundary(ctx context.Context, postState state.Beaco
 
 	if postState.Slot()+1 == s.nextEpochBoundarySlot {
 		// Update caches for the next epoch at epoch boundary slot - 1.
-		if err := helpers.UpdateCommitteeCache(postState, core.NextEpoch(postState)); err != nil {
+		if err := helpers.UpdateCommitteeCache(postState, coreTime.NextEpoch(postState)); err != nil {
 			return err
 		}
 		copied := postState.Copy()
@@ -323,7 +360,7 @@ func (s *Service) handleEpochBoundary(ctx context.Context, postState state.Beaco
 		if err != nil {
 			return err
 		}
-		if err := helpers.UpdateProposerIndicesInCache(copied); err != nil {
+		if err := helpers.UpdateProposerIndicesInCache(ctx, copied); err != nil {
 			return err
 		}
 	} else if postState.Slot() >= s.nextEpochBoundarySlot {
@@ -331,17 +368,17 @@ func (s *Service) handleEpochBoundary(ctx context.Context, postState state.Beaco
 			return err
 		}
 		var err error
-		s.nextEpochBoundarySlot, err = core.StartSlot(core.NextEpoch(postState))
+		s.nextEpochBoundarySlot, err = slots.EpochStart(coreTime.NextEpoch(postState))
 		if err != nil {
 			return err
 		}
 
 		// Update caches at epoch boundary slot.
 		// The following updates have short cut to return nil cheaply if fulfilled during boundary slot - 1.
-		if err := helpers.UpdateCommitteeCache(postState, core.CurrentEpoch(postState)); err != nil {
+		if err := helpers.UpdateCommitteeCache(postState, coreTime.CurrentEpoch(postState)); err != nil {
 			return err
 		}
-		if err := helpers.UpdateProposerIndicesInCache(postState); err != nil {
+		if err := helpers.UpdateProposerIndicesInCache(ctx, postState); err != nil {
 			return err
 		}
 	}
@@ -363,7 +400,7 @@ func (s *Service) insertBlockAndAttestationsToForkChoiceStore(ctx context.Contex
 	}
 	// Feed in block's attestations to fork choice store.
 	for _, a := range blk.Body().Attestations() {
-		committee, err := helpers.BeaconCommitteeFromState(st, a.Data.Slot, a.Data.CommitteeIndex)
+		committee, err := helpers.BeaconCommitteeFromState(ctx, st, a.Data.Slot, a.Data.CommitteeIndex)
 		if err != nil {
 			return err
 		}

beacon-chain/blockchain/process_block_helpers.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -16,12 +15,13 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/block"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )
 
 // CurrentSlot returns the current slot based on time.
 func (s *Service) CurrentSlot() types.Slot {
-	return core.CurrentSlot(uint64(s.genesisTime.Unix()))
+	return slots.CurrentSlot(uint64(s.genesisTime.Unix()))
 }
 
 // getBlockPreState returns the pre state of an incoming block. It uses the parent root of the block
@@ -45,7 +45,7 @@ func (s *Service) getBlockPreState(ctx context.Context, b block.BeaconBlock) (st
 	}
 
 	// Verify block slot time is not from the future.
-	if err := core.VerifySlotTime(preState.GenesisTime(), b.Slot(), params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
+	if err := slots.VerifyTime(preState.GenesisTime(), b.Slot(), params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
 		return nil, err
 	}
 
@@ -122,7 +122,7 @@ func (s *Service) VerifyBlkDescendant(ctx context.Context, root [32]byte) error
 // verifyBlkFinalizedSlot validates input block is not less than or equal
 // to current finalized slot.
 func (s *Service) verifyBlkFinalizedSlot(b block.BeaconBlock) error {
-	finalizedSlot, err := core.StartSlot(s.finalizedCheckpt.Epoch)
+	finalizedSlot, err := slots.EpochStart(s.finalizedCheckpt.Epoch)
 	if err != nil {
 		return err
 	}
@@ -140,7 +140,7 @@ func (s *Service) shouldUpdateCurrentJustified(ctx context.Context, newJustified
 	ctx, span := trace.StartSpan(ctx, "blockChain.shouldUpdateCurrentJustified")
 	defer span.End()
 
-	if core.SlotsSinceEpochStarts(s.CurrentSlot()) < params.BeaconConfig().SafeSlotsToUpdateJustified {
+	if slots.SinceEpochStarts(s.CurrentSlot()) < params.BeaconConfig().SafeSlotsToUpdateJustified {
 		return true, nil
 	}
 	var newJustifiedBlockSigned block.SignedBeaconBlock
@@ -159,7 +159,7 @@ func (s *Service) shouldUpdateCurrentJustified(ctx context.Context, newJustified
 	}
 
 	newJustifiedBlock := newJustifiedBlockSigned.Block()
-	jSlot, err := core.StartSlot(s.justifiedCheckpt.Epoch)
+	jSlot, err := slots.EpochStart(s.justifiedCheckpt.Epoch)
 	if err != nil {
 		return false, err
 	}
@@ -212,7 +212,7 @@ func (s *Service) updateJustified(ctx context.Context, state state.ReadOnlyBeaco
 		}
 	}
 
-	return s.cfg.BeaconDB.SaveJustifiedCheckpoint(ctx, cpt)
+	return nil
 }
 
 // This caches input checkpoint as justified for the service struct. It rotates current justified to previous justified,
@@ -348,7 +348,7 @@ func (s *Service) finalizedImpliesNewJustified(ctx context.Context, state state.
 		}
 
 		// Update justified if store justified is not in chain with finalized check point.
-		finalizedSlot, err := core.StartSlot(s.finalizedCheckpt.Epoch)
+		finalizedSlot, err := slots.EpochStart(s.finalizedCheckpt.Epoch)
 		if err != nil {
 			return err
 		}
@@ -377,7 +377,7 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, blk block.B
 	parentRoot := bytesutil.ToBytes32(blk.ParentRoot())
 	slot := blk.Slot()
 	// Fork choice only matters from last finalized slot.
-	fSlot, err := core.StartSlot(s.finalizedCheckpt.Epoch)
+	fSlot, err := slots.EpochStart(s.finalizedCheckpt.Epoch)
 	if err != nil {
 		return err
 	}

beacon-chain/blockchain/process_block_test.go

@@ -957,6 +957,14 @@ func TestOnBlock_CanFinalize(t *testing.T) {
 	}
 	require.Equal(t, types.Epoch(3), service.CurrentJustifiedCheckpt().Epoch)
 	require.Equal(t, types.Epoch(2), service.FinalizedCheckpt().Epoch)
+
+	// The update should persist in DB.
+	j, err := service.cfg.BeaconDB.JustifiedCheckpoint(ctx)
+	require.NoError(t, err)
+	require.Equal(t, j.Epoch, service.CurrentJustifiedCheckpt().Epoch)
+	f, err := service.cfg.BeaconDB.FinalizedCheckpoint(ctx)
+	require.NoError(t, err)
+	require.Equal(t, f.Epoch, service.FinalizedCheckpt().Epoch)
 }
 
 func TestInsertFinalizedDeposits(t *testing.T) {

beacon-chain/blockchain/receive_attestation.go

@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
@@ -19,10 +18,16 @@ import (
 	"go.opencensus.io/trace"
 )
 
+// AttestationStateFetcher allows for retrieving a beacon state corresponding to the block
+// root of an attestation's target checkpoint.
+type AttestationStateFetcher interface {
+	AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.BeaconState, error)
+}
+
 // AttestationReceiver interface defines the methods of chain service receive and processing new attestations.
 type AttestationReceiver interface {
+	AttestationStateFetcher
 	ReceiveAttestationNoPubsub(ctx context.Context, att *ethpb.Attestation) error
-	AttestationPreState(ctx context.Context, att *ethpb.Attestation) (state.BeaconState, error)
 	VerifyLmdFfgConsistency(ctx context.Context, att *ethpb.Attestation) error
 	VerifyFinalizedConsistency(ctx context.Context, root []byte) error
 }
@@ -43,21 +48,21 @@ func (s *Service) ReceiveAttestationNoPubsub(ctx context.Context, att *ethpb.Att
 	return nil
 }
 
-// AttestationPreState returns the pre state of attestation.
-func (s *Service) AttestationPreState(ctx context.Context, att *ethpb.Attestation) (state.BeaconState, error) {
-	ss, err := core.StartSlot(att.Data.Target.Epoch)
+// AttestationTargetState returns the pre state of attestation.
+func (s *Service) AttestationTargetState(ctx context.Context, target *ethpb.Checkpoint) (state.BeaconState, error) {
+	ss, err := slots.EpochStart(target.Epoch)
 	if err != nil {
 		return nil, err
 	}
-	if err := core.ValidateSlotClock(ss, uint64(s.genesisTime.Unix())); err != nil {
+	if err := slots.ValidateClock(ss, uint64(s.genesisTime.Unix())); err != nil {
 		return nil, err
 	}
-	return s.getAttPreState(ctx, att.Data.Target)
+	return s.getAttPreState(ctx, target)
 }
 
 // VerifyLmdFfgConsistency verifies that attestation's LMD and FFG votes are consistency to each other.
 func (s *Service) VerifyLmdFfgConsistency(ctx context.Context, a *ethpb.Attestation) error {
-	targetSlot, err := core.StartSlot(a.Data.Target.Epoch)
+	targetSlot, err := slots.EpochStart(a.Data.Target.Epoch)
 	if err != nil {
 		return err
 	}
@@ -82,7 +87,7 @@ func (s *Service) VerifyFinalizedConsistency(ctx context.Context, root []byte) e
 	}
 
 	f := s.FinalizedCheckpt()
-	ss, err := core.StartSlot(f.Epoch)
+	ss, err := slots.EpochStart(f.Epoch)
 	if err != nil {
 		return err
 	}
@@ -141,7 +146,7 @@ func (s *Service) processAttestations(ctx context.Context) {
 		// This delays consideration in the fork choice until their slot is in the past.
 		// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/fork-choice.md#validate_on_attestation
 		nextSlot := a.Data.Slot + 1
-		if err := core.VerifySlotTime(uint64(s.genesisTime.Unix()), nextSlot, params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
+		if err := slots.VerifyTime(uint64(s.genesisTime.Unix()), nextSlot, params.BeaconNetworkConfig().MaximumGossipClockDisparity); err != nil {
 			continue
 		}
 

beacon-chain/blockchain/receive_attestation_test.go

@@ -6,7 +6,6 @@ import (
 	"time"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/transition"
 	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
@@ -20,9 +19,15 @@ import (
 	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/prysmaticlabs/prysm/testing/util"
 	prysmTime "github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )
 
+var (
+	_ = AttestationReceiver(&Service{})
+	_ = AttestationStateFetcher(&Service{})
+)
+
 func TestAttestationCheckPtState_FarFutureSlot(t *testing.T) {
 	helpers.ClearCache()
 	beaconDB := testDB.SetupDB(t)
@@ -30,8 +35,8 @@ func TestAttestationCheckPtState_FarFutureSlot(t *testing.T) {
 	chainService := setupBeaconChain(t, beaconDB)
 	chainService.genesisTime = time.Now()
 
-	e := types.Epoch(core.MaxSlotBuffer/uint64(params.BeaconConfig().SlotsPerEpoch) + 1)
-	_, err := chainService.AttestationPreState(context.Background(), &ethpb.Attestation{Data: &ethpb.AttestationData{Target: &ethpb.Checkpoint{Epoch: e}}})
+	e := types.Epoch(slots.MaxSlotBuffer/uint64(params.BeaconConfig().SlotsPerEpoch) + 1)
+	_, err := chainService.AttestationTargetState(context.Background(), &ethpb.Checkpoint{Epoch: e})
 	require.ErrorContains(t, "exceeds max allowed value relative to the local clock", err)
 }
 

beacon-chain/blockchain/receive_block.go

@@ -5,12 +5,12 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/monitoring/tracing"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/block"
 	"github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"go.opencensus.io/trace"
 )
 
@@ -142,7 +142,7 @@ func (s *Service) handlePostBlockOperations(b block.BeaconBlock) error {
 // This checks whether it's time to start saving hot state to DB.
 // It's time when there's `epochsSinceFinalitySaveHotStateDB` epochs of non-finality.
 func (s *Service) checkSaveHotStateDB(ctx context.Context) error {
-	currentEpoch := core.SlotToEpoch(s.CurrentSlot())
+	currentEpoch := slots.ToEpoch(s.CurrentSlot())
 	// Prevent `sinceFinality` going underflow.
 	var sinceFinality types.Epoch
 	if currentEpoch > s.finalizedCheckpt.Epoch {

beacon-chain/blockchain/service.go

@@ -11,9 +11,9 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
+	"github.com/prysmaticlabs/prysm/async/event"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache/depositcache"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
@@ -82,6 +82,7 @@ type Config struct {
 	ForkChoiceStore         f.ForkChoicer
 	AttService              *attestations.Service
 	StateGen                *stategen.State
+	SlasherAttestationsFeed *event.Feed
 	WeakSubjectivityCheckpt *ethpb.Checkpoint
 }
 
@@ -174,7 +175,7 @@ func (s *Service) Start() {
 		s.prevFinalizedCheckpt = ethpb.CopyCheckpoint(finalizedCheckpoint)
 		s.resumeForkChoice(justifiedCheckpoint, finalizedCheckpoint)
 
-		ss, err := core.StartSlot(s.finalizedCheckpt.Epoch)
+		ss, err := slots.EpochStart(s.finalizedCheckpt.Epoch)
 		if err != nil {
 			log.Fatalf("Could not get start slot of finalized epoch: %v", err)
 		}
@@ -296,7 +297,7 @@ func (s *Service) initializeBeaconChain(
 	if err := helpers.UpdateCommitteeCache(genesisState, 0 /* genesis epoch */); err != nil {
 		return nil, err
 	}
-	if err := helpers.UpdateProposerIndicesInCache(genesisState); err != nil {
+	if err := helpers.UpdateProposerIndicesInCache(ctx, genesisState); err != nil {
 		return nil, err
 	}
 
@@ -411,7 +412,7 @@ func (s *Service) initializeChainInfo(ctx context.Context) error {
 		if err != nil {
 			return errors.Wrap(err, "could not retrieve head block")
 		}
-		headEpoch := core.SlotToEpoch(headBlock.Block().Slot())
+		headEpoch := slots.ToEpoch(headBlock.Block().Slot())
 		var epochsSinceFinality types.Epoch
 		if headEpoch > finalized.Epoch {
 			epochsSinceFinality = headEpoch - finalized.Epoch

beacon-chain/blockchain/service_test.go

@@ -10,7 +10,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/prysmaticlabs/prysm/async/event"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache/depositcache"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	b "github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
@@ -33,6 +32,7 @@ import (
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 	"google.golang.org/protobuf/proto"
 )
@@ -281,7 +281,7 @@ func TestChainService_InitializeChainInfo(t *testing.T) {
 	require.NoError(t, beaconDB.SaveState(ctx, headState, headRoot))
 	require.NoError(t, beaconDB.SaveState(ctx, headState, genesisRoot))
 	require.NoError(t, beaconDB.SaveBlock(ctx, wrapper.WrappedPhase0SignedBeaconBlock(headBlock)))
-	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: core.SlotToEpoch(finalizedSlot), Root: headRoot[:]}))
+	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{Epoch: slots.ToEpoch(finalizedSlot), Root: headRoot[:]}))
 	c := &Service{cfg: &Config{BeaconDB: beaconDB, StateGen: stategen.New(beaconDB)}}
 	require.NoError(t, c.initializeChainInfo(ctx))
 	headBlk, err := c.HeadBlock(ctx)
@@ -375,7 +375,7 @@ func TestChainService_InitializeChainInfo_HeadSync(t *testing.T) {
 	require.NoError(t, beaconDB.SaveState(ctx, headState, headRoot))
 	require.NoError(t, beaconDB.SaveHeadBlockRoot(ctx, headRoot))
 	require.NoError(t, beaconDB.SaveFinalizedCheckpoint(ctx, &ethpb.Checkpoint{
-		Epoch: core.SlotToEpoch(finalizedBlock.Block.Slot),
+		Epoch: slots.ToEpoch(finalizedBlock.Block.Slot),
 		Root:  finalizedRoot[:],
 	}))
 

beacon-chain/blockchain/testing/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing",
     visibility = [
         "//beacon-chain:__subpackages__",
+        "//testing:__subpackages__",
         "//testing/fuzz:__pkg__",
     ],
     deps = [

beacon-chain/blockchain/testing/mock.go

@@ -294,17 +294,17 @@ func (s *ChainService) ReceiveAttestationNoPubsub(context.Context, *ethpb.Attest
 	return nil
 }
 
-// AttestationPreState mocks AttestationPreState method in chain service.
-func (s *ChainService) AttestationPreState(_ context.Context, _ *ethpb.Attestation) (state.BeaconState, error) {
+// AttestationTargetState mocks AttestationTargetState method in chain service.
+func (s *ChainService) AttestationTargetState(_ context.Context, _ *ethpb.Checkpoint) (state.BeaconState, error) {
 	return s.State, nil
 }
 
 // HeadValidatorsIndices mocks the same method in the chain service.
-func (s *ChainService) HeadValidatorsIndices(_ context.Context, epoch types.Epoch) ([]types.ValidatorIndex, error) {
+func (s *ChainService) HeadValidatorsIndices(ctx context.Context, epoch types.Epoch) ([]types.ValidatorIndex, error) {
 	if s.State == nil {
 		return []types.ValidatorIndex{}, nil
 	}
-	return helpers.ActiveValidatorIndices(s.State, epoch)
+	return helpers.ActiveValidatorIndices(ctx, s.State, epoch)
 }
 
 // HeadSeed mocks the same method in the chain service.

beacon-chain/blockchain/weak_subjectivity_checks.go

@@ -4,10 +4,10 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // VerifyWeakSubjectivityRoot verifies the weak subjectivity root in the service struct.
@@ -38,7 +38,7 @@ func (s *Service) VerifyWeakSubjectivityRoot(ctx context.Context) error {
 		return fmt.Errorf("node does not have root in DB: %#x", r)
 	}
 
-	startSlot, err := core.StartSlot(s.cfg.WeakSubjectivityCheckpt.Epoch)
+	startSlot, err := slots.EpochStart(s.cfg.WeakSubjectivityCheckpt.Epoch)
 	if err != nil {
 		return err
 	}

beacon-chain/cache/committee.go

@@ -3,8 +3,11 @@
 package cache
 
 import (
+	"context"
 	"errors"
+	"math"
 	"sync"
+	"time"
 
 	lru "github.com/hashicorp/golang-lru"
 	"github.com/prometheus/client_golang/prometheus"
@@ -13,7 +16,7 @@ import (
 	lruwrpr "github.com/prysmaticlabs/prysm/cache/lru"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/container/slice"
-	"github.com/prysmaticlabs/prysm/math"
+	mathutil "github.com/prysmaticlabs/prysm/math"
 )
 
 var (
@@ -37,6 +40,7 @@ var (
 type CommitteeCache struct {
 	CommitteeCache *lru.Cache
 	lock           sync.RWMutex
+	inProgress     map[string]bool
 }
 
 // committeeKeyFn takes the seed as the key to retrieve shuffled indices of a committee in a given epoch.
@@ -52,14 +56,16 @@ func committeeKeyFn(obj interface{}) (string, error) {
 func NewCommitteesCache() *CommitteeCache {
 	return &CommitteeCache{
 		CommitteeCache: lruwrpr.New(int(maxCommitteesCacheSize)),
+		inProgress:     make(map[string]bool),
 	}
 }
 
 // Committee fetches the shuffled indices by slot and committee index. Every list of indices
 // represent one committee. Returns true if the list exists with slot and committee index. Otherwise returns false, nil.
-func (c *CommitteeCache) Committee(slot types.Slot, seed [32]byte, index types.CommitteeIndex) ([]types.ValidatorIndex, error) {
-	c.lock.RLock()
-	defer c.lock.RUnlock()
+func (c *CommitteeCache) Committee(ctx context.Context, slot types.Slot, seed [32]byte, index types.CommitteeIndex) ([]types.ValidatorIndex, error) {
+	if err := c.checkInProgress(ctx, seed); err != nil {
+		return nil, err
+	}
 
 	obj, exists := c.CommitteeCache.Get(key(seed))
 	if exists {
@@ -79,7 +85,7 @@ func (c *CommitteeCache) Committee(slot types.Slot, seed [32]byte, index types.C
 		committeeCountPerSlot = item.CommitteeCount / uint64(params.BeaconConfig().SlotsPerEpoch)
 	}
 
-	indexOffSet, err := math.Add64(uint64(index), uint64(slot.ModSlot(params.BeaconConfig().SlotsPerEpoch).Mul(committeeCountPerSlot)))
+	indexOffSet, err := mathutil.Add64(uint64(index), uint64(slot.ModSlot(params.BeaconConfig().SlotsPerEpoch).Mul(committeeCountPerSlot)))
 	if err != nil {
 		return nil, err
 	}
@@ -106,9 +112,10 @@ func (c *CommitteeCache) AddCommitteeShuffledList(committees *Committees) error
 }
 
 // ActiveIndices returns the active indices of a given seed stored in cache.
-func (c *CommitteeCache) ActiveIndices(seed [32]byte) ([]types.ValidatorIndex, error) {
-	c.lock.RLock()
-	defer c.lock.RUnlock()
+func (c *CommitteeCache) ActiveIndices(ctx context.Context, seed [32]byte) ([]types.ValidatorIndex, error) {
+	if err := c.checkInProgress(ctx, seed); err != nil {
+		return nil, err
+	}
 	obj, exists := c.CommitteeCache.Get(key(seed))
 
 	if exists {
@@ -127,9 +134,11 @@ func (c *CommitteeCache) ActiveIndices(seed [32]byte) ([]types.ValidatorIndex, e
 }
 
 // ActiveIndicesCount returns the active indices count of a given seed stored in cache.
-func (c *CommitteeCache) ActiveIndicesCount(seed [32]byte) (int, error) {
-	c.lock.RLock()
-	defer c.lock.RUnlock()
+func (c *CommitteeCache) ActiveIndicesCount(ctx context.Context, seed [32]byte) (int, error) {
+	if err := c.checkInProgress(ctx, seed); err != nil {
+		return 0, err
+	}
+
 	obj, exists := c.CommitteeCache.Get(key(seed))
 	if exists {
 		CommitteeCacheHit.Inc()
@@ -152,6 +161,29 @@ func (c *CommitteeCache) HasEntry(seed string) bool {
 	return ok
 }
 
+// MarkInProgress a request so that any other similar requests will block on
+// Get until MarkNotInProgress is called.
+func (c *CommitteeCache) MarkInProgress(seed [32]byte) error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	s := key(seed)
+	if c.inProgress[s] {
+		return ErrAlreadyInProgress
+	}
+	c.inProgress[s] = true
+	return nil
+}
+
+// MarkNotInProgress will release the lock on a given request. This should be
+// called after put.
+func (c *CommitteeCache) MarkNotInProgress(seed [32]byte) error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	s := key(seed)
+	delete(c.inProgress, s)
+	return nil
+}
+
 func startEndIndices(c *Committees, index uint64) (uint64, uint64) {
 	validatorCount := uint64(len(c.ShuffledIndices))
 	start := slice.SplitOffset(validatorCount, c.CommitteeCount, index)
@@ -166,3 +198,28 @@ func startEndIndices(c *Committees, index uint64) (uint64, uint64) {
 func key(seed [32]byte) string {
 	return string(seed[:])
 }
+
+func (c *CommitteeCache) checkInProgress(ctx context.Context, seed [32]byte) error {
+	delay := minDelay
+	// Another identical request may be in progress already. Let's wait until
+	// any in progress request resolves or our timeout is exceeded.
+	for {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+
+		c.lock.RLock()
+		if !c.inProgress[key(seed)] {
+			c.lock.RUnlock()
+			break
+		}
+		c.lock.RUnlock()
+
+		// This increasing backoff is to decrease the CPU cycles while waiting
+		// for the in progress boolean to flip to false.
+		time.Sleep(time.Duration(delay) * time.Nanosecond)
+		delay *= delayFactor
+		delay = math.Min(delay, maxDelay)
+	}
+	return nil
+}

beacon-chain/cache/committee_disabled.go

@@ -3,7 +3,11 @@
 // This file is used in fuzzer builds to bypass global committee caches.
 package cache
 
-import types "github.com/prysmaticlabs/eth2-types"
+import (
+	"context"
+
+	types "github.com/prysmaticlabs/eth2-types"
+)
 
 // FakeCommitteeCache is a struct with 1 queue for looking up shuffled indices list by seed.
 type FakeCommitteeCache struct {
@@ -16,7 +20,7 @@ func NewCommitteesCache() *FakeCommitteeCache {
 
 // Committee fetches the shuffled indices by slot and committee index. Every list of indices
 // represent one committee. Returns true if the list exists with slot and committee index. Otherwise returns false, nil.
-func (c *FakeCommitteeCache) Committee(slot types.Slot, seed [32]byte, index types.CommitteeIndex) ([]types.ValidatorIndex, error) {
+func (c *FakeCommitteeCache) Committee(ctx context.Context, slot types.Slot, seed [32]byte, index types.CommitteeIndex) ([]types.ValidatorIndex, error) {
 	return nil, nil
 }
 
@@ -32,12 +36,12 @@ func (c *FakeCommitteeCache) AddProposerIndicesList(seed [32]byte, indices []typ
 }
 
 // ActiveIndices returns the active indices of a given seed stored in cache.
-func (c *FakeCommitteeCache) ActiveIndices(seed [32]byte) ([]types.ValidatorIndex, error) {
+func (c *FakeCommitteeCache) ActiveIndices(ctx context.Context, seed [32]byte) ([]types.ValidatorIndex, error) {
 	return nil, nil
 }
 
 // ActiveIndicesCount returns the active indices count of a given seed stored in cache.
-func (c *FakeCommitteeCache) ActiveIndicesCount(seed [32]byte) (int, error) {
+func (c *FakeCommitteeCache) ActiveIndicesCount(ctx context.Context, seed [32]byte) (int, error) {
 	return 0, nil
 }
 
@@ -55,3 +59,13 @@ func (c *FakeCommitteeCache) ProposerIndices(seed [32]byte) ([]types.ValidatorIn
 func (c *FakeCommitteeCache) HasEntry(string) bool {
 	return false
 }
+
+// MarkInProgress is a stub.
+func (c *FakeCommitteeCache) MarkInProgress(seed [32]byte) error {
+	return nil
+}
+
+// MarkNotInProgress is a stub.
+func (c *FakeCommitteeCache) MarkNotInProgress(seed [32]byte) error {
+	return nil
+}

beacon-chain/cache/committee_fuzz_test.go

@@ -1,6 +1,7 @@
 package cache
 
 import (
+	"context"
 	"testing"
 
 	fuzz "github.com/google/gofuzz"
@@ -28,7 +29,7 @@ func TestCommitteeCache_FuzzCommitteesByEpoch(t *testing.T) {
 	for i := 0; i < 100000; i++ {
 		fuzzer.Fuzz(c)
 		require.NoError(t, cache.AddCommitteeShuffledList(c))
-		_, err := cache.Committee(0, c.Seed, 0)
+		_, err := cache.Committee(context.Background(), 0, c.Seed, 0)
 		require.NoError(t, err)
 	}
 
@@ -44,7 +45,7 @@ func TestCommitteeCache_FuzzActiveIndices(t *testing.T) {
 		fuzzer.Fuzz(c)
 		require.NoError(t, cache.AddCommitteeShuffledList(c))
 
-		indices, err := cache.ActiveIndices(c.Seed)
+		indices, err := cache.ActiveIndices(context.Background(), c.Seed)
 		require.NoError(t, err)
 		assert.DeepEqual(t, c.SortedIndices, indices)
 	}

beacon-chain/cache/committee_test.go

@@ -1,6 +1,7 @@
 package cache
 
 import (
+	"context"
 	"math"
 	"sort"
 	"strconv"
@@ -41,7 +42,7 @@ func TestCommitteeCache_CommitteesByEpoch(t *testing.T) {
 
 	slot := params.BeaconConfig().SlotsPerEpoch
 	committeeIndex := types.CommitteeIndex(1)
-	indices, err := cache.Committee(slot, item.Seed, committeeIndex)
+	indices, err := cache.Committee(context.Background(), slot, item.Seed, committeeIndex)
 	require.NoError(t, err)
 	if indices != nil {
 		t.Error("Expected committee not to exist in empty cache")
@@ -49,7 +50,7 @@ func TestCommitteeCache_CommitteesByEpoch(t *testing.T) {
 	require.NoError(t, cache.AddCommitteeShuffledList(item))
 
 	wantedIndex := types.CommitteeIndex(0)
-	indices, err = cache.Committee(slot, item.Seed, wantedIndex)
+	indices, err = cache.Committee(context.Background(), slot, item.Seed, wantedIndex)
 	require.NoError(t, err)
 
 	start, end := startEndIndices(item, uint64(wantedIndex))
@@ -60,7 +61,7 @@ func TestCommitteeCache_ActiveIndices(t *testing.T) {
 	cache := NewCommitteesCache()
 
 	item := &Committees{Seed: [32]byte{'A'}, SortedIndices: []types.ValidatorIndex{1, 2, 3, 4, 5, 6}}
-	indices, err := cache.ActiveIndices(item.Seed)
+	indices, err := cache.ActiveIndices(context.Background(), item.Seed)
 	require.NoError(t, err)
 	if indices != nil {
 		t.Error("Expected committee not to exist in empty cache")
@@ -68,7 +69,7 @@ func TestCommitteeCache_ActiveIndices(t *testing.T) {
 
 	require.NoError(t, cache.AddCommitteeShuffledList(item))
 
-	indices, err = cache.ActiveIndices(item.Seed)
+	indices, err = cache.ActiveIndices(context.Background(), item.Seed)
 	require.NoError(t, err)
 	assert.DeepEqual(t, item.SortedIndices, indices)
 }
@@ -77,13 +78,13 @@ func TestCommitteeCache_ActiveCount(t *testing.T) {
 	cache := NewCommitteesCache()
 
 	item := &Committees{Seed: [32]byte{'A'}, SortedIndices: []types.ValidatorIndex{1, 2, 3, 4, 5, 6}}
-	count, err := cache.ActiveIndicesCount(item.Seed)
+	count, err := cache.ActiveIndicesCount(context.Background(), item.Seed)
 	require.NoError(t, err)
 	assert.Equal(t, 0, count, "Expected active count not to exist in empty cache")
 
 	require.NoError(t, cache.AddCommitteeShuffledList(item))
 
-	count, err = cache.ActiveIndicesCount(item.Seed)
+	count, err = cache.ActiveIndicesCount(context.Background(), item.Seed)
 	require.NoError(t, err)
 	assert.Equal(t, len(item.SortedIndices), count)
 }
@@ -127,6 +128,6 @@ func TestCommitteeCacheOutOfRange(t *testing.T) {
 	assert.NoError(t, err)
 	_ = cache.CommitteeCache.Add(key, comms)
 
-	_, err = cache.Committee(0, seed, math.MaxUint64) // Overflow!
+	_, err = cache.Committee(context.Background(), 0, seed, math.MaxUint64) // Overflow!
 	require.NotNil(t, err, "Did not fail as expected")
 }

beacon-chain/cache/committees.go

@@ -10,9 +10,6 @@ import (
 // a Committee struct.
 var ErrNotCommittee = errors.New("object is not a committee struct")
 
-// ErrNonCommitteeKey will be returned when the committee key does not exist in cache.
-var ErrNonCommitteeKey = errors.New("committee key does not exist")
-
 // Committees defines the shuffled committees seed.
 type Committees struct {
 	CommitteeCount  uint64

beacon-chain/core/altair/BUILD.bazel

@@ -21,11 +21,12 @@ go_library(
         "//validator/client:__pkg__",
     ],
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/blocks:go_default_library",
         "//beacon-chain/core/epoch:go_default_library",
         "//beacon-chain/core/epoch/precompute:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/p2p/types:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/v2:go_default_library",
@@ -37,6 +38,7 @@ go_library(
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/attestation:go_default_library",
         "//proto/prysm/v1alpha1/block:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
@@ -60,10 +62,11 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/epoch:go_default_library",
         "//beacon-chain/core/epoch/precompute:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/p2p/types:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/v2:go_default_library",
@@ -79,6 +82,7 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_google_gofuzz//:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",

beacon-chain/core/altair/attestation.go

@@ -7,9 +7,9 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
@@ -65,7 +65,7 @@ func ProcessAttestationNoVerifySignature(
 	if err != nil {
 		return nil, err
 	}
-	committee, err := helpers.BeaconCommitteeFromState(beaconState, att.Data.Slot, att.Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(ctx, beaconState, att.Data.Slot, att.Data.CommitteeIndex)
 	if err != nil {
 		return nil, err
 	}
@@ -74,7 +74,7 @@ func ProcessAttestationNoVerifySignature(
 		return nil, err
 	}
 
-	return SetParticipationAndRewardProposer(beaconState, att.Data.Target.Epoch, indices, participatedFlags, totalBalance)
+	return SetParticipationAndRewardProposer(ctx, beaconState, att.Data.Target.Epoch, indices, participatedFlags, totalBalance)
 }
 
 // SetParticipationAndRewardProposer retrieves and sets the epoch participation bits in state. Based on the epoch participation, it rewards
@@ -99,12 +99,13 @@ func ProcessAttestationNoVerifySignature(
 //    proposer_reward = Gwei(proposer_reward_numerator // proposer_reward_denominator)
 //    increase_balance(state, get_beacon_proposer_index(state), proposer_reward)
 func SetParticipationAndRewardProposer(
+	ctx context.Context,
 	beaconState state.BeaconState,
 	targetEpoch types.Epoch,
 	indices []uint64,
 	participatedFlags map[uint8]bool, totalBalance uint64) (state.BeaconState, error) {
 	var epochParticipation []byte
-	currentEpoch := core.CurrentEpoch(beaconState)
+	currentEpoch := time.CurrentEpoch(beaconState)
 	var err error
 	if targetEpoch == currentEpoch {
 		epochParticipation, err = beaconState.CurrentEpochParticipation()
@@ -133,7 +134,7 @@ func SetParticipationAndRewardProposer(
 		}
 	}
 
-	if err := RewardProposer(beaconState, proposerRewardNumerator); err != nil {
+	if err := RewardProposer(ctx, beaconState, proposerRewardNumerator); err != nil {
 		return nil, err
 	}
 
@@ -196,11 +197,11 @@ func EpochParticipation(beaconState state.BeaconState, indices []uint64, epochPa
 //    proposer_reward_denominator = (WEIGHT_DENOMINATOR - PROPOSER_WEIGHT) * WEIGHT_DENOMINATOR // PROPOSER_WEIGHT
 //    proposer_reward = Gwei(proposer_reward_numerator // proposer_reward_denominator)
 //    increase_balance(state, get_beacon_proposer_index(state), proposer_reward)
-func RewardProposer(beaconState state.BeaconState, proposerRewardNumerator uint64) error {
+func RewardProposer(ctx context.Context, beaconState state.BeaconState, proposerRewardNumerator uint64) error {
 	cfg := params.BeaconConfig()
 	d := (cfg.WeightDenominator - cfg.ProposerWeight) * cfg.WeightDenominator / cfg.ProposerWeight
 	proposerReward := proposerRewardNumerator / d
-	i, err := helpers.BeaconProposerIndex(beaconState)
+	i, err := helpers.BeaconProposerIndex(ctx, beaconState)
 	if err != nil {
 		return err
 	}
@@ -239,7 +240,7 @@ func RewardProposer(beaconState state.BeaconState, proposerRewardNumerator uint6
 //
 //    return participation_flag_indices
 func AttestationParticipationFlagIndices(beaconState state.BeaconStateAltair, data *ethpb.AttestationData, delay types.Slot) (map[uint8]bool, error) {
-	currEpoch := core.CurrentEpoch(beaconState)
+	currEpoch := time.CurrentEpoch(beaconState)
 	var justifiedCheckpt *ethpb.Checkpoint
 	if data.Target.Epoch == currEpoch {
 		justifiedCheckpt = beaconState.CurrentJustifiedCheckpoint()

beacon-chain/core/altair/attestation_test.go

@@ -8,9 +8,10 @@ import (
 	fuzz "github.com/google/gofuzz"
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	stateAltair "github.com/prysmaticlabs/prysm/beacon-chain/state/v2"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -74,8 +75,8 @@ func TestProcessAttestations_NeitherCurrentNorPrevEpoch(t *testing.T) {
 	want := fmt.Sprintf(
 		"expected target epoch (%d) to be the previous epoch (%d) or the current epoch (%d)",
 		att.Data.Target.Epoch,
-		core.PrevEpoch(beaconState),
-		core.CurrentEpoch(beaconState),
+		time.PrevEpoch(beaconState),
+		time.CurrentEpoch(beaconState),
 	)
 	wsb, err := wrapper.WrappedAltairSignedBeaconBlock(b)
 	require.NoError(t, err)
@@ -110,7 +111,7 @@ func TestProcessAttestations_CurrentEpochFFGDataMismatches(t *testing.T) {
 	require.NoError(t, err)
 	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, want, err)
-	b.Block.Body.Attestations[0].Data.Source.Epoch = core.CurrentEpoch(beaconState)
+	b.Block.Body.Attestations[0].Data.Source.Epoch = time.CurrentEpoch(beaconState)
 	b.Block.Body.Attestations[0].Data.Source.Root = []byte{}
 	wsb, err = wrapper.WrappedAltairSignedBeaconBlock(b)
 	require.NoError(t, err)
@@ -151,8 +152,8 @@ func TestProcessAttestations_PrevEpochFFGDataMismatches(t *testing.T) {
 	require.NoError(t, err)
 	_, err = altair.ProcessAttestationsNoVerifySignature(context.Background(), beaconState, wsb)
 	require.ErrorContains(t, want, err)
-	b.Block.Body.Attestations[0].Data.Source.Epoch = core.PrevEpoch(beaconState)
-	b.Block.Body.Attestations[0].Data.Target.Epoch = core.PrevEpoch(beaconState)
+	b.Block.Body.Attestations[0].Data.Source.Epoch = time.PrevEpoch(beaconState)
+	b.Block.Body.Attestations[0].Data.Target.Epoch = time.PrevEpoch(beaconState)
 	b.Block.Body.Attestations[0].Data.Source.Root = []byte{}
 	wsb, err = wrapper.WrappedAltairSignedBeaconBlock(b)
 	require.NoError(t, err)
@@ -211,13 +212,13 @@ func TestProcessAttestations_OK(t *testing.T) {
 	cfc.Root = mockRoot[:]
 	require.NoError(t, beaconState.SetCurrentJustifiedCheckpoint(cfc))
 
-	committee, err := helpers.BeaconCommitteeFromState(beaconState, att.Data.Slot, att.Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(context.Background(), beaconState, att.Data.Slot, att.Data.CommitteeIndex)
 	require.NoError(t, err)
 	attestingIndices, err := attestation.AttestingIndices(att.AggregationBits, committee)
 	require.NoError(t, err)
 	sigs := make([]bls.Signature, len(attestingIndices))
 	for i, indice := range attestingIndices {
-		sb, err := helpers.ComputeDomainAndSign(beaconState, 0, att.Data, params.BeaconConfig().DomainBeaconAttester, privKeys[indice])
+		sb, err := signing.ComputeDomainAndSign(beaconState, 0, att.Data, params.BeaconConfig().DomainBeaconAttester, privKeys[indice])
 		require.NoError(t, err)
 		sig, err := bls.SignatureFromBytes(sb)
 		require.NoError(t, err)
@@ -269,7 +270,7 @@ func TestProcessAttestationNoVerify_SourceTargetHead(t *testing.T) {
 	p, err := beaconState.CurrentEpochParticipation()
 	require.NoError(t, err)
 
-	committee, err := helpers.BeaconCommitteeFromState(beaconState, att.Data.Slot, att.Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(context.Background(), beaconState, att.Data.Slot, att.Data.CommitteeIndex)
 	require.NoError(t, err)
 	indices, err := attestation.AttestingIndices(att.AggregationBits, committee)
 	require.NoError(t, err)
@@ -388,7 +389,6 @@ func TestFuzzProcessAttestationsNoVerify_10000(t *testing.T) {
 	fuzzer := fuzz.NewWithSeed(0)
 	state := &ethpb.BeaconStateAltair{}
 	b := &ethpb.SignedBeaconBlockAltair{Block: &ethpb.BeaconBlockAltair{}}
-	ctx := context.Background()
 	for i := 0; i < 10000; i++ {
 		fuzzer.Fuzz(state)
 		fuzzer.Fuzz(b)
@@ -399,7 +399,7 @@ func TestFuzzProcessAttestationsNoVerify_10000(t *testing.T) {
 		require.NoError(t, err)
 		wsb, err := wrapper.WrappedAltairSignedBeaconBlock(b)
 		require.NoError(t, err)
-		r, err := altair.ProcessAttestationsNoVerifySignature(ctx, s, wsb)
+		r, err := altair.ProcessAttestationsNoVerifySignature(context.Background(), s, wsb)
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and block: %v", r, err, state, b)
 		}
@@ -471,7 +471,7 @@ func TestSetParticipationAndRewardProposer(t *testing.T) {
 			beaconState, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().MaxValidatorsPerCommittee)
 			require.NoError(t, beaconState.SetSlot(params.BeaconConfig().SlotsPerEpoch))
 
-			currentEpoch := core.CurrentEpoch(beaconState)
+			currentEpoch := time.CurrentEpoch(beaconState)
 			if test.epoch == currentEpoch {
 				require.NoError(t, beaconState.SetCurrentParticipationBits(test.epochParticipation))
 			} else {
@@ -480,10 +480,10 @@ func TestSetParticipationAndRewardProposer(t *testing.T) {
 
 			b, err := helpers.TotalActiveBalance(beaconState)
 			require.NoError(t, err)
-			st, err := altair.SetParticipationAndRewardProposer(beaconState, test.epoch, test.indices, test.participatedFlags, b)
+			st, err := altair.SetParticipationAndRewardProposer(context.Background(), beaconState, test.epoch, test.indices, test.participatedFlags, b)
 			require.NoError(t, err)
 
-			i, err := helpers.BeaconProposerIndex(st)
+			i, err := helpers.BeaconProposerIndex(context.Background(), st)
 			require.NoError(t, err)
 			b, err = beaconState.BalanceAtIndex(i)
 			require.NoError(t, err)
@@ -586,8 +586,8 @@ func TestRewardProposer(t *testing.T) {
 		{rewardNumerator: 1000000000000, want: 34234377253},
 	}
 	for _, test := range tests {
-		require.NoError(t, altair.RewardProposer(beaconState, test.rewardNumerator))
-		i, err := helpers.BeaconProposerIndex(beaconState)
+		require.NoError(t, altair.RewardProposer(context.Background(), beaconState, test.rewardNumerator))
+		i, err := helpers.BeaconProposerIndex(context.Background(), beaconState)
 		require.NoError(t, err)
 		b, err := beaconState.BalanceAtIndex(i)
 		require.NoError(t, err)

beacon-chain/core/altair/block.go

@@ -1,17 +1,19 @@
 package altair
 
 import (
+	"context"
 	"errors"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	p2pType "github.com/prysmaticlabs/prysm/beacon-chain/p2p/types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // ProcessSyncAggregate verifies sync committee aggregate signature signing over the previous slot block root.
@@ -42,7 +44,7 @@ import (
 //            increase_balance(state, get_beacon_proposer_index(state), proposer_reward)
 //        else:
 //            decrease_balance(state, participant_index, participant_reward)
-func ProcessSyncAggregate(s state.BeaconStateAltair, sync *ethpb.SyncAggregate) (state.BeaconStateAltair, error) {
+func ProcessSyncAggregate(ctx context.Context, s state.BeaconStateAltair, sync *ethpb.SyncAggregate) (state.BeaconStateAltair, error) {
 	votedKeys, votedIndices, didntVoteIndices, err := FilterSyncCommitteeVotes(s, sync)
 	if err != nil {
 		return nil, err
@@ -52,7 +54,7 @@ func ProcessSyncAggregate(s state.BeaconStateAltair, sync *ethpb.SyncAggregate)
 		return nil, err
 	}
 
-	return ApplySyncRewardsPenalties(s, votedIndices, didntVoteIndices)
+	return ApplySyncRewardsPenalties(ctx, s, votedIndices, didntVoteIndices)
 }
 
 // FilterSyncCommitteeVotes filters the validator public keys and indices for the ones that voted and didn't vote.
@@ -99,8 +101,8 @@ func FilterSyncCommitteeVotes(s state.BeaconStateAltair, sync *ethpb.SyncAggrega
 
 // VerifySyncCommitteeSig verifies sync committee signature `syncSig` is valid with respect to public keys `syncKeys`.
 func VerifySyncCommitteeSig(s state.BeaconStateAltair, syncKeys []bls.PublicKey, syncSig []byte) error {
-	ps := core.PrevSlot(s.Slot())
-	d, err := helpers.Domain(s.Fork(), core.SlotToEpoch(ps), params.BeaconConfig().DomainSyncCommittee, s.GenesisValidatorRoot())
+	ps := slots.PrevSlot(s.Slot())
+	d, err := signing.Domain(s.Fork(), slots.ToEpoch(ps), params.BeaconConfig().DomainSyncCommittee, s.GenesisValidatorRoot())
 	if err != nil {
 		return err
 	}
@@ -109,7 +111,7 @@ func VerifySyncCommitteeSig(s state.BeaconStateAltair, syncKeys []bls.PublicKey,
 		return err
 	}
 	sszBytes := p2pType.SSZBytes(pbr)
-	r, err := helpers.ComputeSigningRoot(&sszBytes, d)
+	r, err := signing.ComputeSigningRoot(&sszBytes, d)
 	if err != nil {
 		return err
 	}
@@ -124,7 +126,7 @@ func VerifySyncCommitteeSig(s state.BeaconStateAltair, syncKeys []bls.PublicKey,
 }
 
 // ApplySyncRewardsPenalties applies rewards and penalties for proposer and sync committee participants.
-func ApplySyncRewardsPenalties(s state.BeaconStateAltair, votedIndices, didntVoteIndices []types.ValidatorIndex) (state.BeaconStateAltair, error) {
+func ApplySyncRewardsPenalties(ctx context.Context, s state.BeaconStateAltair, votedIndices, didntVoteIndices []types.ValidatorIndex) (state.BeaconStateAltair, error) {
 	activeBalance, err := helpers.TotalActiveBalance(s)
 	if err != nil {
 		return nil, err
@@ -143,7 +145,7 @@ func ApplySyncRewardsPenalties(s state.BeaconStateAltair, votedIndices, didntVot
 		earnedProposerReward += proposerReward
 	}
 	// Apply proposer rewards.
-	proposerIndex, err := helpers.BeaconProposerIndex(s)
+	proposerIndex, err := helpers.BeaconProposerIndex(ctx, s)
 	if err != nil {
 		return nil, err
 	}

beacon-chain/core/altair/block_test.go

@@ -7,9 +7,10 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	p2pType "github.com/prysmaticlabs/prysm/beacon-chain/p2p/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -17,6 +18,7 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 func TestProcessSyncCommittee_PerfectParticipation(t *testing.T) {
@@ -32,13 +34,13 @@ func TestProcessSyncCommittee_PerfectParticipation(t *testing.T) {
 	}
 	indices, err := altair.NextSyncCommitteeIndices(context.Background(), beaconState)
 	require.NoError(t, err)
-	ps := core.PrevSlot(beaconState.Slot())
+	ps := slots.PrevSlot(beaconState.Slot())
 	pbr, err := helpers.BlockRootAtSlot(beaconState, ps)
 	require.NoError(t, err)
 	sigs := make([]bls.Signature, len(indices))
 	for i, indice := range indices {
 		b := p2pType.SSZBytes(pbr)
-		sb, err := helpers.ComputeDomainAndSign(beaconState, core.CurrentEpoch(beaconState), &b, params.BeaconConfig().DomainSyncCommittee, privKeys[indice])
+		sb, err := signing.ComputeDomainAndSign(beaconState, time.CurrentEpoch(beaconState), &b, params.BeaconConfig().DomainSyncCommittee, privKeys[indice])
 		require.NoError(t, err)
 		sig, err := bls.SignatureFromBytes(sb)
 		require.NoError(t, err)
@@ -50,7 +52,7 @@ func TestProcessSyncCommittee_PerfectParticipation(t *testing.T) {
 		SyncCommitteeSignature: aggregatedSig,
 	}
 
-	beaconState, err = altair.ProcessSyncAggregate(beaconState, syncAggregate)
+	beaconState, err = altair.ProcessSyncAggregate(context.Background(), beaconState, syncAggregate)
 	require.NoError(t, err)
 
 	// Use a non-sync committee index to compare profitability.
@@ -71,7 +73,7 @@ func TestProcessSyncCommittee_PerfectParticipation(t *testing.T) {
 	require.Equal(t, true, balances[indices[0]] > balances[nonSyncIndex])
 
 	// Proposer should be more profitable than rest of the sync committee
-	proposerIndex, err := helpers.BeaconProposerIndex(beaconState)
+	proposerIndex, err := helpers.BeaconProposerIndex(context.Background(), beaconState)
 	require.NoError(t, err)
 	require.Equal(t, true, balances[proposerIndex] > balances[indices[0]])
 
@@ -106,13 +108,13 @@ func TestProcessSyncCommittee_MixParticipation_BadSignature(t *testing.T) {
 	}
 	indices, err := altair.NextSyncCommitteeIndices(context.Background(), beaconState)
 	require.NoError(t, err)
-	ps := core.PrevSlot(beaconState.Slot())
+	ps := slots.PrevSlot(beaconState.Slot())
 	pbr, err := helpers.BlockRootAtSlot(beaconState, ps)
 	require.NoError(t, err)
 	sigs := make([]bls.Signature, len(indices))
 	for i, indice := range indices {
 		b := p2pType.SSZBytes(pbr)
-		sb, err := helpers.ComputeDomainAndSign(beaconState, core.CurrentEpoch(beaconState), &b, params.BeaconConfig().DomainSyncCommittee, privKeys[indice])
+		sb, err := signing.ComputeDomainAndSign(beaconState, time.CurrentEpoch(beaconState), &b, params.BeaconConfig().DomainSyncCommittee, privKeys[indice])
 		require.NoError(t, err)
 		sig, err := bls.SignatureFromBytes(sb)
 		require.NoError(t, err)
@@ -124,7 +126,7 @@ func TestProcessSyncCommittee_MixParticipation_BadSignature(t *testing.T) {
 		SyncCommitteeSignature: aggregatedSig,
 	}
 
-	_, err = altair.ProcessSyncAggregate(beaconState, syncAggregate)
+	_, err = altair.ProcessSyncAggregate(context.Background(), beaconState, syncAggregate)
 	require.ErrorContains(t, "invalid sync committee signature", err)
 }
 
@@ -141,14 +143,14 @@ func TestProcessSyncCommittee_MixParticipation_GoodSignature(t *testing.T) {
 	}
 	indices, err := altair.NextSyncCommitteeIndices(context.Background(), beaconState)
 	require.NoError(t, err)
-	ps := core.PrevSlot(beaconState.Slot())
+	ps := slots.PrevSlot(beaconState.Slot())
 	pbr, err := helpers.BlockRootAtSlot(beaconState, ps)
 	require.NoError(t, err)
 	sigs := make([]bls.Signature, 0, len(indices))
 	for i, indice := range indices {
 		if syncBits.BitAt(uint64(i)) {
 			b := p2pType.SSZBytes(pbr)
-			sb, err := helpers.ComputeDomainAndSign(beaconState, core.CurrentEpoch(beaconState), &b, params.BeaconConfig().DomainSyncCommittee, privKeys[indice])
+			sb, err := signing.ComputeDomainAndSign(beaconState, time.CurrentEpoch(beaconState), &b, params.BeaconConfig().DomainSyncCommittee, privKeys[indice])
 			require.NoError(t, err)
 			sig, err := bls.SignatureFromBytes(sb)
 			require.NoError(t, err)
@@ -161,7 +163,7 @@ func TestProcessSyncCommittee_MixParticipation_GoodSignature(t *testing.T) {
 		SyncCommitteeSignature: aggregatedSig,
 	}
 
-	_, err = altair.ProcessSyncAggregate(beaconState, syncAggregate)
+	_, err = altair.ProcessSyncAggregate(context.Background(), beaconState, syncAggregate)
 	require.NoError(t, err)
 }
 
@@ -214,14 +216,14 @@ func Test_VerifySyncCommitteeSig(t *testing.T) {
 	}
 	indices, err := altair.NextSyncCommitteeIndices(context.Background(), beaconState)
 	require.NoError(t, err)
-	ps := core.PrevSlot(beaconState.Slot())
+	ps := slots.PrevSlot(beaconState.Slot())
 	pbr, err := helpers.BlockRootAtSlot(beaconState, ps)
 	require.NoError(t, err)
 	sigs := make([]bls.Signature, len(indices))
 	pks := make([]bls.PublicKey, len(indices))
 	for i, indice := range indices {
 		b := p2pType.SSZBytes(pbr)
-		sb, err := helpers.ComputeDomainAndSign(beaconState, core.CurrentEpoch(beaconState), &b, params.BeaconConfig().DomainSyncCommittee, privKeys[indice])
+		sb, err := signing.ComputeDomainAndSign(beaconState, time.CurrentEpoch(beaconState), &b, params.BeaconConfig().DomainSyncCommittee, privKeys[indice])
 		require.NoError(t, err)
 		sig, err := bls.SignatureFromBytes(sb)
 		require.NoError(t, err)
@@ -239,7 +241,7 @@ func Test_VerifySyncCommitteeSig(t *testing.T) {
 
 func Test_ApplySyncRewardsPenalties(t *testing.T) {
 	beaconState, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().MaxValidatorsPerCommittee)
-	beaconState, err := altair.ApplySyncRewardsPenalties(beaconState,
+	beaconState, err := altair.ApplySyncRewardsPenalties(context.Background(), beaconState,
 		[]types.ValidatorIndex{0, 1}, // voted
 		[]types.ValidatorIndex{2, 3}) // didn't vote
 	require.NoError(t, err)
@@ -248,7 +250,7 @@ func Test_ApplySyncRewardsPenalties(t *testing.T) {
 	require.Equal(t, balances[0], balances[1])
 	require.Equal(t, uint64(31999999012), balances[2])
 	require.Equal(t, balances[2], balances[3])
-	proposerIndex, err := helpers.BeaconProposerIndex(beaconState)
+	proposerIndex, err := helpers.BeaconProposerIndex(context.Background(), beaconState)
 	require.NoError(t, err)
 	require.Equal(t, uint64(32000000282), balances[proposerIndex])
 }

beacon-chain/core/altair/deposit_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	stateAltair "github.com/prysmaticlabs/prysm/beacon-chain/state/v2"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/container/trie"
@@ -119,7 +119,7 @@ func TestProcessDeposits_RepeatedDeposit_IncreasesValidatorBalance(t *testing.T)
 			Signature:             make([]byte, 96),
 		},
 	}
-	sr, err := helpers.ComputeSigningRoot(deposit.Data, bytesutil.ToBytes(3, 32))
+	sr, err := signing.ComputeSigningRoot(deposit.Data, bytesutil.ToBytes(3, 32))
 	require.NoError(t, err)
 	sig := sk.Sign(sr[:])
 	deposit.Data.Signature = sig.Marshal()

beacon-chain/core/altair/epoch_precompute.go

@@ -4,9 +4,9 @@ import (
 	"context"
 
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch/precompute"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/math"
@@ -19,8 +19,8 @@ func InitializePrecomputeValidators(ctx context.Context, beaconState state.Beaco
 	defer span.End()
 	vals := make([]*precompute.Validator, beaconState.NumValidators())
 	bal := &precompute.Balance{}
-	prevEpoch := core.PrevEpoch(beaconState)
-	currentEpoch := core.CurrentEpoch(beaconState)
+	prevEpoch := time.PrevEpoch(beaconState)
+	currentEpoch := time.CurrentEpoch(beaconState)
 	inactivityScores, err := beaconState.InactivityScores()
 	if err != nil {
 		return nil, nil, err
@@ -74,7 +74,7 @@ func ProcessInactivityScores(
 	defer span.End()
 
 	cfg := params.BeaconConfig()
-	if core.CurrentEpoch(beaconState) == cfg.GenesisEpoch {
+	if time.CurrentEpoch(beaconState) == cfg.GenesisEpoch {
 		return beaconState, vals, nil
 	}
 
@@ -85,7 +85,7 @@ func ProcessInactivityScores(
 
 	bias := cfg.InactivityScoreBias
 	recoveryRate := cfg.InactivityScoreRecoveryRate
-	prevEpoch := core.PrevEpoch(beaconState)
+	prevEpoch := time.PrevEpoch(beaconState)
 	finalizedEpoch := beaconState.FinalizedCheckpointEpoch()
 	for i, v := range vals {
 		if !precompute.EligibleForRewards(v) {
@@ -98,7 +98,10 @@ func ProcessInactivityScores(
 				v.InactivityScore -= 1
 			}
 		} else {
-			v.InactivityScore += bias
+			v.InactivityScore, err = math.Add64(v.InactivityScore, bias)
+			if err != nil {
+				return nil, nil, err
+			}
 		}
 
 		if !helpers.IsInInactivityLeak(prevEpoch, finalizedEpoch) {
@@ -179,7 +182,7 @@ func ProcessRewardsAndPenaltiesPrecompute(
 ) (state.BeaconStateAltair, error) {
 	// Don't process rewards and penalties in genesis epoch.
 	cfg := params.BeaconConfig()
-	if core.CurrentEpoch(beaconState) == cfg.GenesisEpoch {
+	if time.CurrentEpoch(beaconState) == cfg.GenesisEpoch {
 		return beaconState, nil
 	}
 
@@ -200,7 +203,10 @@ func ProcessRewardsAndPenaltiesPrecompute(
 
 		// Compute the post balance of the validator after accounting for the
 		// attester and proposer rewards and penalties.
-		balances[i] = helpers.IncreaseBalanceWithVal(balances[i], attsRewards[i])
+		balances[i], err = helpers.IncreaseBalanceWithVal(balances[i], attsRewards[i])
+		if err != nil {
+			return nil, err
+		}
 		balances[i] = helpers.DecreaseBalanceWithVal(balances[i], attsPenalties[i])
 
 		vals[i].AfterEpochTransitionBalance = balances[i]
@@ -221,7 +227,7 @@ func AttestationsDelta(beaconState state.BeaconStateAltair, bal *precompute.Bala
 	penalties = make([]uint64, numOfVals)
 
 	cfg := params.BeaconConfig()
-	prevEpoch := core.PrevEpoch(beaconState)
+	prevEpoch := time.PrevEpoch(beaconState)
 	finalizedEpoch := beaconState.FinalizedCheckpointEpoch()
 	increment := cfg.EffectiveBalanceIncrement
 	factor := cfg.BaseRewardFactor
@@ -230,7 +236,10 @@ func AttestationsDelta(beaconState state.BeaconStateAltair, bal *precompute.Bala
 	inactivityDenominator := cfg.InactivityScoreBias * cfg.InactivityPenaltyQuotientAltair
 
 	for i, v := range vals {
-		rewards[i], penalties[i] = attestationDelta(bal, v, baseRewardMultiplier, inactivityDenominator, leak)
+		rewards[i], penalties[i], err = attestationDelta(bal, v, baseRewardMultiplier, inactivityDenominator, leak)
+		if err != nil {
+			return nil, nil, err
+		}
 	}
 
 	return rewards, penalties, nil
@@ -240,11 +249,11 @@ func attestationDelta(
 	bal *precompute.Balance,
 	val *precompute.Validator,
 	baseRewardMultiplier, inactivityDenominator uint64,
-	inactivityLeak bool) (reward, penalty uint64) {
+	inactivityLeak bool) (reward, penalty uint64, err error) {
 	eligible := val.IsActivePrevEpoch || (val.IsSlashed && !val.IsWithdrawableCurrentEpoch)
 	// Per spec `ActiveCurrentEpoch` can't be 0 to process attestation delta.
 	if !eligible || bal.ActiveCurrentEpoch == 0 {
-		return 0, 0
+		return 0, 0, nil
 	}
 
 	cfg := params.BeaconConfig()
@@ -289,9 +298,12 @@ func attestationDelta(
 	// Process finality delay penalty
 	// Apply an additional penalty to validators that did not vote on the correct target or slashed
 	if !val.IsPrevEpochTargetAttester || val.IsSlashed {
-		n := effectiveBalance * val.InactivityScore
+		n, err := math.Mul64(effectiveBalance, val.InactivityScore)
+		if err != nil {
+			return 0, 0, err
+		}
 		penalty += n / inactivityDenominator
 	}
 
-	return reward, penalty
+	return reward, penalty, nil
 }

beacon-chain/core/altair/epoch_spec.go

@@ -3,8 +3,8 @@ package altair
 import (
 	"context"
 
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	log "github.com/sirupsen/logrus"
@@ -19,7 +19,7 @@ import (
 //        state.current_sync_committee = state.next_sync_committee
 //        state.next_sync_committee = get_next_sync_committee(state)
 func ProcessSyncCommitteeUpdates(ctx context.Context, beaconState state.BeaconStateAltair) (state.BeaconStateAltair, error) {
-	nextEpoch := core.NextEpoch(beaconState)
+	nextEpoch := time.NextEpoch(beaconState)
 	if nextEpoch%params.BeaconConfig().EpochsPerSyncCommitteePeriod == 0 {
 		nextSyncCommittee, err := beaconState.NextSyncCommittee()
 		if err != nil {

beacon-chain/core/altair/epoch_spec_test.go

@@ -3,13 +3,14 @@ package altair_test
 import (
 	"context"
 	"fmt"
+	"math"
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	stateAltair "github.com/prysmaticlabs/prysm/beacon-chain/state/v2"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
@@ -58,7 +59,7 @@ func TestProcessSyncCommitteeUpdates_CanRotate(t *testing.T) {
 	require.DeepEqual(t, next, c)
 
 	// Test boundary condition.
-	slot := params.BeaconConfig().SlotsPerEpoch * types.Slot(core.CurrentEpoch(s)+params.BeaconConfig().EpochsPerSyncCommitteePeriod)
+	slot := params.BeaconConfig().SlotsPerEpoch * types.Slot(time.CurrentEpoch(s)+params.BeaconConfig().EpochsPerSyncCommitteePeriod)
 	require.NoError(t, s.SetSlot(slot))
 	boundaryCommittee, err := altair.NextSyncCommittee(context.Background(), s)
 	require.NoError(t, err)
@@ -181,3 +182,16 @@ func TestProcessSlashings_SlashedLess(t *testing.T) {
 		})
 	}
 }
+
+func TestProcessSlashings_BadValue(t *testing.T) {
+	base := &ethpb.BeaconStateAltair{
+		Slot:       0,
+		Validators: []*ethpb.Validator{{Slashed: true}},
+		Balances:   []uint64{params.BeaconConfig().MaxEffectiveBalance},
+		Slashings:  []uint64{math.MaxUint64, 1e9},
+	}
+	s, err := stateAltair.InitializeFromProto(base)
+	require.NoError(t, err)
+	_, err = epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplierAltair)
+	require.ErrorContains(t, "addition overflows", err)
+}

beacon-chain/core/altair/sync_committee.go

@@ -7,8 +7,8 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	coreTime "github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -16,6 +16,7 @@ import (
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/math"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 const maxRandomByte = uint64(1<<8 - 1)
@@ -97,8 +98,8 @@ func NextSyncCommittee(ctx context.Context, s state.BeaconStateAltair) (*ethpb.S
 //        i += 1
 //    return sync_committee_indices
 func NextSyncCommitteeIndices(ctx context.Context, s state.BeaconStateAltair) ([]types.ValidatorIndex, error) {
-	epoch := core.NextEpoch(s)
-	indices, err := helpers.ActiveValidatorIndices(s, epoch)
+	epoch := coreTime.NextEpoch(s)
+	indices, err := helpers.ActiveValidatorIndices(ctx, s, epoch)
 	if err != nil {
 		return nil, err
 	}
@@ -185,15 +186,15 @@ func IsSyncCommitteeAggregator(sig []byte) (bool, error) {
 
 // ValidateSyncMessageTime validates sync message to ensure that the provided slot is valid.
 func ValidateSyncMessageTime(slot types.Slot, genesisTime time.Time, clockDisparity time.Duration) error {
-	if err := core.ValidateSlotClock(slot, uint64(genesisTime.Unix())); err != nil {
+	if err := slots.ValidateClock(slot, uint64(genesisTime.Unix())); err != nil {
 		return err
 	}
-	messageTime, err := core.SlotToTime(uint64(genesisTime.Unix()), slot)
+	messageTime, err := slots.ToTime(uint64(genesisTime.Unix()), slot)
 	if err != nil {
 		return err
 	}
-	currentSlot := core.SlotsSince(genesisTime)
-	slotStartTime, err := core.SlotToTime(uint64(genesisTime.Unix()), currentSlot)
+	currentSlot := slots.Since(genesisTime)
+	slotStartTime, err := slots.ToTime(uint64(genesisTime.Unix()), currentSlot)
 	if err != nil {
 		return err
 	}
@@ -214,8 +215,8 @@ func ValidateSyncMessageTime(slot types.Slot, genesisTime time.Time, clockDispar
 		return fmt.Errorf(
 			"sync message slot %d not within allowable range of %d to %d (current slot)",
 			slot,
-			lowerBound.Unix(),
-			upperBound.Unix(),
+			uint64(lowerBound.Unix()-genesisTime.Unix())/params.BeaconConfig().SecondsPerSlot,
+			uint64(upperBound.Unix()-genesisTime.Unix())/params.BeaconConfig().SecondsPerSlot,
 		)
 	}
 	return nil

beacon-chain/core/altair/transition.go

@@ -63,7 +63,7 @@ func ProcessEpoch(ctx context.Context, state state.BeaconStateAltair) (state.Bea
 		return nil, errors.Wrap(err, "could not process rewards and penalties")
 	}
 
-	state, err = e.ProcessRegistryUpdates(state)
+	state, err = e.ProcessRegistryUpdates(ctx, state)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process registry updates")
 	}

beacon-chain/core/altair/upgrade.go

@@ -3,8 +3,8 @@ package altair
 import (
 	"context"
 
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	statealtair "github.com/prysmaticlabs/prysm/beacon-chain/state/v2"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -63,7 +63,7 @@ import (
 //    post.next_sync_committee = get_next_sync_committee(post)
 //    return post
 func UpgradeToAltair(ctx context.Context, state state.BeaconState) (state.BeaconStateAltair, error) {
-	epoch := core.CurrentEpoch(state)
+	epoch := time.CurrentEpoch(state)
 
 	numValidators := state.NumValidators()
 	s := &ethpb.BeaconStateAltair{
@@ -103,7 +103,7 @@ func UpgradeToAltair(ctx context.Context, state state.BeaconState) (state.Beacon
 	if err != nil {
 		return nil, err
 	}
-	newState, err = TranslateParticipation(newState, prevEpochAtts)
+	newState, err = TranslateParticipation(ctx, newState, prevEpochAtts)
 	if err != nil {
 		return nil, err
 	}
@@ -137,7 +137,7 @@ func UpgradeToAltair(ctx context.Context, state state.BeaconState) (state.Beacon
 //        for index in get_attesting_indices(state, data, attestation.aggregation_bits):
 //            for flag_index in participation_flag_indices:
 //                epoch_participation[index] = add_flag(epoch_participation[index], flag_index)
-func TranslateParticipation(state *statealtair.BeaconState, atts []*ethpb.PendingAttestation) (*statealtair.BeaconState, error) {
+func TranslateParticipation(ctx context.Context, state *statealtair.BeaconState, atts []*ethpb.PendingAttestation) (*statealtair.BeaconState, error) {
 	epochParticipation, err := state.PreviousEpochParticipation()
 	if err != nil {
 		return nil, err
@@ -148,7 +148,7 @@ func TranslateParticipation(state *statealtair.BeaconState, atts []*ethpb.Pendin
 		if err != nil {
 			return nil, err
 		}
-		committee, err := helpers.BeaconCommitteeFromState(state, att.Data.Slot, att.Data.CommitteeIndex)
+		committee, err := helpers.BeaconCommitteeFromState(ctx, state, att.Data.Slot, att.Data.CommitteeIndex)
 		if err != nil {
 			return nil, err
 		}

beacon-chain/core/altair/upgrade_test.go

@@ -6,9 +6,9 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	stateAltair "github.com/prysmaticlabs/prysm/beacon-chain/state/v2"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -19,13 +19,14 @@ import (
 )
 
 func TestTranslateParticipation(t *testing.T) {
+	ctx := context.Background()
 	s, _ := util.DeterministicGenesisStateAltair(t, 64)
 	st, ok := s.(*stateAltair.BeaconState)
 	require.Equal(t, true, ok)
 	require.NoError(t, st.SetSlot(st.Slot()+params.BeaconConfig().MinAttestationInclusionDelay))
 
 	var err error
-	newState, err := altair.TranslateParticipation(st, nil)
+	newState, err := altair.TranslateParticipation(ctx, st, nil)
 	require.NoError(t, err)
 	participation, err := newState.PreviousEpochParticipation()
 	require.NoError(t, err)
@@ -50,13 +51,13 @@ func TestTranslateParticipation(t *testing.T) {
 		})
 	}
 
-	newState, err = altair.TranslateParticipation(newState, pendingAtts)
+	newState, err = altair.TranslateParticipation(ctx, newState, pendingAtts)
 	require.NoError(t, err)
 	participation, err = newState.PreviousEpochParticipation()
 	require.NoError(t, err)
 	require.DeepNotSSZEqual(t, make([]byte, 64), participation)
 
-	committee, err := helpers.BeaconCommitteeFromState(st, pendingAtts[0].Data.Slot, pendingAtts[0].Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(ctx, st, pendingAtts[0].Data.Slot, pendingAtts[0].Data.CommitteeIndex)
 	require.NoError(t, err)
 	indices, err := attestation.AttestingIndices(pendingAtts[0].AggregationBits, committee)
 	require.NoError(t, err)
@@ -108,7 +109,7 @@ func TestUpgradeToAltair(t *testing.T) {
 	require.DeepSSZEqual(t, &ethpb.Fork{
 		PreviousVersion: st.Fork().CurrentVersion,
 		CurrentVersion:  params.BeaconConfig().AltairForkVersion,
-		Epoch:           core.CurrentEpoch(st),
+		Epoch:           time.CurrentEpoch(st),
 	}, f)
 	csc, err := aState.CurrentSyncCommittee()
 	require.NoError(t, err)

beacon-chain/core/blocks/BUILD.bazel

@@ -21,11 +21,12 @@ go_library(
         "//testing/fuzz:__pkg__",
         "//testing/spectest:__subpackages__",
         "//testing/util:__pkg__",
-        "//validator/accounts:__pkg__",
+        "//validator:__subpackages__",
     ],
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/validators:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/params:go_default_library",
@@ -42,6 +43,7 @@ go_library(
         "//proto/prysm/v1alpha1/block:go_default_library",
         "//proto/prysm/v1alpha1/slashings:go_default_library",
         "//runtime/version:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
@@ -73,8 +75,9 @@ go_test(
     embed = [":go_default_library"],
     shard_count = 2,
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/validators:go_default_library",
         "//beacon-chain/p2p/types:go_default_library",
         "//beacon-chain/state:go_default_library",
@@ -91,6 +94,7 @@ go_test(
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_google_gofuzz//:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",

beacon-chain/core/blocks/attestation.go

@@ -6,8 +6,9 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -51,8 +52,8 @@ func VerifyAttestationNoVerifySignature(
 	if err := helpers.ValidateNilAttestation(att); err != nil {
 		return err
 	}
-	currEpoch := core.CurrentEpoch(beaconState)
-	prevEpoch := core.PrevEpoch(beaconState)
+	currEpoch := time.CurrentEpoch(beaconState)
+	prevEpoch := time.PrevEpoch(beaconState)
 	data := att.Data
 	if data.Target.Epoch != prevEpoch && data.Target.Epoch != currEpoch {
 		return fmt.Errorf(
@@ -96,7 +97,7 @@ func VerifyAttestationNoVerifySignature(
 			params.BeaconConfig().SlotsPerEpoch,
 		)
 	}
-	activeValidatorCount, err := helpers.ActiveValidatorCount(beaconState, att.Data.Target.Epoch)
+	activeValidatorCount, err := helpers.ActiveValidatorCount(ctx, beaconState, att.Data.Target.Epoch)
 	if err != nil {
 		return err
 	}
@@ -105,12 +106,12 @@ func VerifyAttestationNoVerifySignature(
 		return fmt.Errorf("committee index %d >= committee count %d", att.Data.CommitteeIndex, c)
 	}
 
-	if err := helpers.VerifyAttestationBitfieldLengths(beaconState, att); err != nil {
+	if err := helpers.VerifyAttestationBitfieldLengths(ctx, beaconState, att); err != nil {
 		return errors.Wrap(err, "could not verify attestation bitfields")
 	}
 
 	// Verify attesting indices are correct.
-	committee, err := helpers.BeaconCommitteeFromState(beaconState, att.Data.Slot, att.Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(ctx, beaconState, att.Data.Slot, att.Data.CommitteeIndex)
 	if err != nil {
 		return err
 	}
@@ -136,10 +137,10 @@ func ProcessAttestationNoVerifySignature(
 		return nil, err
 	}
 
-	currEpoch := core.CurrentEpoch(beaconState)
+	currEpoch := time.CurrentEpoch(beaconState)
 	data := att.Data
 	s := att.Data.Slot
-	proposerIndex, err := helpers.BeaconProposerIndex(beaconState)
+	proposerIndex, err := helpers.BeaconProposerIndex(ctx, beaconState)
 	if err != nil {
 		return nil, err
 	}
@@ -169,7 +170,7 @@ func VerifyAttestationSignature(ctx context.Context, beaconState state.ReadOnlyB
 	if err := helpers.ValidateNilAttestation(att); err != nil {
 		return err
 	}
-	committee, err := helpers.BeaconCommitteeFromState(beaconState, att.Data.Slot, att.Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(ctx, beaconState, att.Data.Slot, att.Data.CommitteeIndex)
 	if err != nil {
 		return err
 	}
@@ -203,7 +204,7 @@ func VerifyIndexedAttestation(ctx context.Context, beaconState state.ReadOnlyBea
 	if err := attestation.IsValidAttestationIndices(ctx, indexedAtt); err != nil {
 		return err
 	}
-	domain, err := helpers.Domain(
+	domain, err := signing.Domain(
 		beaconState.Fork(),
 		indexedAtt.Data.Target.Epoch,
 		params.BeaconConfig().DomainBeaconAttester,

beacon-chain/core/blocks/attestation_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -40,13 +41,13 @@ func TestProcessAggregatedAttestation_OverlappingBits(t *testing.T) {
 	require.NoError(t, beaconState.SetCurrentJustifiedCheckpoint(cfc))
 	require.NoError(t, beaconState.AppendCurrentEpochAttestations(&ethpb.PendingAttestation{}))
 
-	committee, err := helpers.BeaconCommitteeFromState(beaconState, att1.Data.Slot, att1.Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(context.Background(), beaconState, att1.Data.Slot, att1.Data.CommitteeIndex)
 	require.NoError(t, err)
 	attestingIndices1, err := attestation.AttestingIndices(att1.AggregationBits, committee)
 	require.NoError(t, err)
 	sigs := make([]bls.Signature, len(attestingIndices1))
 	for i, indice := range attestingIndices1 {
-		sb, err := helpers.ComputeDomainAndSign(beaconState, 0, att1.Data, params.BeaconConfig().DomainBeaconAttester, privKeys[indice])
+		sb, err := signing.ComputeDomainAndSign(beaconState, 0, att1.Data, params.BeaconConfig().DomainBeaconAttester, privKeys[indice])
 		require.NoError(t, err)
 		sig, err := bls.SignatureFromBytes(sb)
 		require.NoError(t, err)
@@ -62,13 +63,13 @@ func TestProcessAggregatedAttestation_OverlappingBits(t *testing.T) {
 		AggregationBits: aggBits2,
 	}
 
-	committee, err = helpers.BeaconCommitteeFromState(beaconState, att2.Data.Slot, att2.Data.CommitteeIndex)
+	committee, err = helpers.BeaconCommitteeFromState(context.Background(), beaconState, att2.Data.Slot, att2.Data.CommitteeIndex)
 	require.NoError(t, err)
 	attestingIndices2, err := attestation.AttestingIndices(att2.AggregationBits, committee)
 	require.NoError(t, err)
 	sigs = make([]bls.Signature, len(attestingIndices2))
 	for i, indice := range attestingIndices2 {
-		sb, err := helpers.ComputeDomainAndSign(beaconState, 0, att2.Data, params.BeaconConfig().DomainBeaconAttester, privKeys[indice])
+		sb, err := signing.ComputeDomainAndSign(beaconState, 0, att2.Data, params.BeaconConfig().DomainBeaconAttester, privKeys[indice])
 		require.NoError(t, err)
 		sig, err := bls.SignatureFromBytes(sb)
 		require.NoError(t, err)
@@ -227,7 +228,7 @@ func TestConvertToIndexed_OK(t *testing.T) {
 			Signature:        att.Signature,
 		}
 
-		committee, err := helpers.BeaconCommitteeFromState(state, att.Data.Slot, att.Data.CommitteeIndex)
+		committee, err := helpers.BeaconCommitteeFromState(context.Background(), state, att.Data.Slot, att.Data.CommitteeIndex)
 		require.NoError(t, err)
 		ia, err := attestation.ConvertToIndexed(context.Background(), att, committee)
 		require.NoError(t, err)
@@ -304,7 +305,7 @@ func TestVerifyIndexedAttestation_OK(t *testing.T) {
 	for _, tt := range tests {
 		var sig []bls.Signature
 		for _, idx := range tt.attestation.AttestingIndices {
-			sb, err := helpers.ComputeDomainAndSign(state, tt.attestation.Data.Target.Epoch, tt.attestation.Data, params.BeaconConfig().DomainBeaconAttester, keys[idx])
+			sb, err := signing.ComputeDomainAndSign(state, tt.attestation.Data.Target.Epoch, tt.attestation.Data, params.BeaconConfig().DomainBeaconAttester, keys[idx])
 			require.NoError(t, err)
 			validatorSig, err := bls.SignatureFromBytes(sb)
 			require.NoError(t, err)
@@ -405,7 +406,7 @@ func TestVerifyAttestations_HandlesPlannedFork(t *testing.T) {
 		PreviousVersion: params.BeaconConfig().GenesisForkVersion,
 	}))
 
-	comm1, err := helpers.BeaconCommitteeFromState(st, 1 /*slot*/, 0 /*committeeIndex*/)
+	comm1, err := helpers.BeaconCommitteeFromState(context.Background(), st, 1 /*slot*/, 0 /*committeeIndex*/)
 	require.NoError(t, err)
 	att1 := util.HydrateAttestation(&ethpb.Attestation{
 		AggregationBits: bitfield.NewBitlist(uint64(len(comm1))),
@@ -413,9 +414,9 @@ func TestVerifyAttestations_HandlesPlannedFork(t *testing.T) {
 			Slot: 1,
 		},
 	})
-	prevDomain, err := helpers.Domain(st.Fork(), st.Fork().Epoch-1, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorRoot())
+	prevDomain, err := signing.Domain(st.Fork(), st.Fork().Epoch-1, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorRoot())
 	require.NoError(t, err)
-	root, err := helpers.ComputeSigningRoot(att1.Data, prevDomain)
+	root, err := signing.ComputeSigningRoot(att1.Data, prevDomain)
 	require.NoError(t, err)
 	var sigs []bls.Signature
 	for i, u := range comm1 {
@@ -424,7 +425,7 @@ func TestVerifyAttestations_HandlesPlannedFork(t *testing.T) {
 	}
 	att1.Signature = bls.AggregateSignatures(sigs).Marshal()
 
-	comm2, err := helpers.BeaconCommitteeFromState(st, 1*params.BeaconConfig().SlotsPerEpoch+1 /*slot*/, 1 /*committeeIndex*/)
+	comm2, err := helpers.BeaconCommitteeFromState(context.Background(), st, 1*params.BeaconConfig().SlotsPerEpoch+1 /*slot*/, 1 /*committeeIndex*/)
 	require.NoError(t, err)
 	att2 := util.HydrateAttestation(&ethpb.Attestation{
 		AggregationBits: bitfield.NewBitlist(uint64(len(comm2))),
@@ -433,9 +434,9 @@ func TestVerifyAttestations_HandlesPlannedFork(t *testing.T) {
 			CommitteeIndex: 1,
 		},
 	})
-	currDomain, err := helpers.Domain(st.Fork(), st.Fork().Epoch, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorRoot())
+	currDomain, err := signing.Domain(st.Fork(), st.Fork().Epoch, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorRoot())
 	require.NoError(t, err)
-	root, err = helpers.ComputeSigningRoot(att2.Data, currDomain)
+	root, err = signing.ComputeSigningRoot(att2.Data, currDomain)
 	require.NoError(t, err)
 	sigs = nil
 	for i, u := range comm2 {
@@ -464,7 +465,7 @@ func TestRetrieveAttestationSignatureSet_VerifiesMultipleAttestations(t *testing
 	require.NoError(t, st.SetSlot(5))
 	require.NoError(t, st.SetValidators(validators))
 
-	comm1, err := helpers.BeaconCommitteeFromState(st, 1 /*slot*/, 0 /*committeeIndex*/)
+	comm1, err := helpers.BeaconCommitteeFromState(context.Background(), st, 1 /*slot*/, 0 /*committeeIndex*/)
 	require.NoError(t, err)
 	att1 := util.HydrateAttestation(&ethpb.Attestation{
 		AggregationBits: bitfield.NewBitlist(uint64(len(comm1))),
@@ -472,9 +473,9 @@ func TestRetrieveAttestationSignatureSet_VerifiesMultipleAttestations(t *testing
 			Slot: 1,
 		},
 	})
-	domain, err := helpers.Domain(st.Fork(), st.Fork().Epoch, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorRoot())
+	domain, err := signing.Domain(st.Fork(), st.Fork().Epoch, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorRoot())
 	require.NoError(t, err)
-	root, err := helpers.ComputeSigningRoot(att1.Data, domain)
+	root, err := signing.ComputeSigningRoot(att1.Data, domain)
 	require.NoError(t, err)
 	var sigs []bls.Signature
 	for i, u := range comm1 {
@@ -483,7 +484,7 @@ func TestRetrieveAttestationSignatureSet_VerifiesMultipleAttestations(t *testing
 	}
 	att1.Signature = bls.AggregateSignatures(sigs).Marshal()
 
-	comm2, err := helpers.BeaconCommitteeFromState(st, 1 /*slot*/, 1 /*committeeIndex*/)
+	comm2, err := helpers.BeaconCommitteeFromState(context.Background(), st, 1 /*slot*/, 1 /*committeeIndex*/)
 	require.NoError(t, err)
 	att2 := util.HydrateAttestation(&ethpb.Attestation{
 		AggregationBits: bitfield.NewBitlist(uint64(len(comm2))),
@@ -492,7 +493,7 @@ func TestRetrieveAttestationSignatureSet_VerifiesMultipleAttestations(t *testing
 			CommitteeIndex: 1,
 		},
 	})
-	root, err = helpers.ComputeSigningRoot(att2.Data, domain)
+	root, err = signing.ComputeSigningRoot(att2.Data, domain)
 	require.NoError(t, err)
 	sigs = nil
 	for i, u := range comm2 {
@@ -528,7 +529,7 @@ func TestRetrieveAttestationSignatureSet_AcrossFork(t *testing.T) {
 	require.NoError(t, st.SetValidators(validators))
 	require.NoError(t, st.SetFork(&ethpb.Fork{Epoch: 1, CurrentVersion: []byte{0, 1, 2, 3}, PreviousVersion: []byte{0, 1, 1, 1}}))
 
-	comm1, err := helpers.BeaconCommitteeFromState(st, 1 /*slot*/, 0 /*committeeIndex*/)
+	comm1, err := helpers.BeaconCommitteeFromState(ctx, st, 1 /*slot*/, 0 /*committeeIndex*/)
 	require.NoError(t, err)
 	att1 := util.HydrateAttestation(&ethpb.Attestation{
 		AggregationBits: bitfield.NewBitlist(uint64(len(comm1))),
@@ -536,9 +537,9 @@ func TestRetrieveAttestationSignatureSet_AcrossFork(t *testing.T) {
 			Slot: 1,
 		},
 	})
-	domain, err := helpers.Domain(st.Fork(), st.Fork().Epoch, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorRoot())
+	domain, err := signing.Domain(st.Fork(), st.Fork().Epoch, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorRoot())
 	require.NoError(t, err)
-	root, err := helpers.ComputeSigningRoot(att1.Data, domain)
+	root, err := signing.ComputeSigningRoot(att1.Data, domain)
 	require.NoError(t, err)
 	var sigs []bls.Signature
 	for i, u := range comm1 {
@@ -547,7 +548,7 @@ func TestRetrieveAttestationSignatureSet_AcrossFork(t *testing.T) {
 	}
 	att1.Signature = bls.AggregateSignatures(sigs).Marshal()
 
-	comm2, err := helpers.BeaconCommitteeFromState(st, 1 /*slot*/, 1 /*committeeIndex*/)
+	comm2, err := helpers.BeaconCommitteeFromState(ctx, st, 1 /*slot*/, 1 /*committeeIndex*/)
 	require.NoError(t, err)
 	att2 := util.HydrateAttestation(&ethpb.Attestation{
 		AggregationBits: bitfield.NewBitlist(uint64(len(comm2))),
@@ -556,7 +557,7 @@ func TestRetrieveAttestationSignatureSet_AcrossFork(t *testing.T) {
 			CommitteeIndex: 1,
 		},
 	})
-	root, err = helpers.ComputeSigningRoot(att2.Data, domain)
+	root, err = signing.ComputeSigningRoot(att2.Data, domain)
 	require.NoError(t, err)
 	sigs = nil
 	for i, u := range comm2 {

beacon-chain/core/blocks/attester_slashing.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -15,6 +14,7 @@ import (
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/slashings"
 	"github.com/prysmaticlabs/prysm/runtime/version"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // ProcessAttesterSlashings is one of the operations performed
@@ -50,7 +50,7 @@ func ProcessAttesterSlashings(
 		sort.SliceStable(slashableIndices, func(i, j int) bool {
 			return slashableIndices[i] < slashableIndices[j]
 		})
-		currentEpoch := core.SlotToEpoch(beaconState.Slot())
+		currentEpoch := slots.ToEpoch(beaconState.Slot())
 		var err error
 		var slashedAny bool
 		var val state.ReadOnlyValidator
@@ -65,7 +65,7 @@ func ProcessAttesterSlashings(
 				if beaconState.Version() == version.Altair {
 					slashingQuotient = cfg.MinSlashingPenaltyQuotientAltair
 				}
-				beaconState, err = slashFunc(beaconState, types.ValidatorIndex(validatorIndex), slashingQuotient, cfg.ProposerRewardQuotient)
+				beaconState, err = slashFunc(ctx, beaconState, types.ValidatorIndex(validatorIndex), slashingQuotient, cfg.ProposerRewardQuotient)
 				if err != nil {
 					return nil, errors.Wrapf(err, "could not slash validator index %d",
 						validatorIndex)

beacon-chain/core/blocks/attester_slashing_test.go

@@ -6,7 +6,7 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	v "github.com/prysmaticlabs/prysm/beacon-chain/core/validators"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -108,9 +108,9 @@ func TestProcessAttesterSlashings_AppliesCorrectStatus(t *testing.T) {
 		},
 		AttestingIndices: []uint64{0, 1},
 	})
-	domain, err := helpers.Domain(beaconState.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, beaconState.GenesisValidatorRoot())
+	domain, err := signing.Domain(beaconState.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, beaconState.GenesisValidatorRoot())
 	require.NoError(t, err)
-	signingRoot, err := helpers.ComputeSigningRoot(att1.Data, domain)
+	signingRoot, err := signing.ComputeSigningRoot(att1.Data, domain)
 	assert.NoError(t, err, "Could not get signing root of beacon block header")
 	sig0 := privKeys[0].Sign(signingRoot[:])
 	sig1 := privKeys[1].Sign(signingRoot[:])
@@ -120,7 +120,7 @@ func TestProcessAttesterSlashings_AppliesCorrectStatus(t *testing.T) {
 	att2 := util.HydrateIndexedAttestation(&ethpb.IndexedAttestation{
 		AttestingIndices: []uint64{0, 1},
 	})
-	signingRoot, err = helpers.ComputeSigningRoot(att2.Data, domain)
+	signingRoot, err = signing.ComputeSigningRoot(att2.Data, domain)
 	assert.NoError(t, err, "Could not get signing root of beacon block header")
 	sig0 = privKeys[0].Sign(signingRoot[:])
 	sig1 = privKeys[1].Sign(signingRoot[:])
@@ -177,9 +177,9 @@ func TestProcessAttesterSlashings_AppliesCorrectStatusAltair(t *testing.T) {
 		},
 		AttestingIndices: []uint64{0, 1},
 	})
-	domain, err := helpers.Domain(beaconState.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, beaconState.GenesisValidatorRoot())
+	domain, err := signing.Domain(beaconState.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, beaconState.GenesisValidatorRoot())
 	require.NoError(t, err)
-	signingRoot, err := helpers.ComputeSigningRoot(att1.Data, domain)
+	signingRoot, err := signing.ComputeSigningRoot(att1.Data, domain)
 	assert.NoError(t, err, "Could not get signing root of beacon block header")
 	sig0 := privKeys[0].Sign(signingRoot[:])
 	sig1 := privKeys[1].Sign(signingRoot[:])
@@ -189,7 +189,7 @@ func TestProcessAttesterSlashings_AppliesCorrectStatusAltair(t *testing.T) {
 	att2 := util.HydrateIndexedAttestation(&ethpb.IndexedAttestation{
 		AttestingIndices: []uint64{0, 1},
 	})
-	signingRoot, err = helpers.ComputeSigningRoot(att2.Data, domain)
+	signingRoot, err = signing.ComputeSigningRoot(att2.Data, domain)
 	assert.NoError(t, err, "Could not get signing root of beacon block header")
 	sig0 = privKeys[0].Sign(signingRoot[:])
 	sig1 = privKeys[1].Sign(signingRoot[:])

beacon-chain/core/blocks/block_operations_fuzz_test.go

@@ -125,7 +125,7 @@ func TestFuzzProcessBlockHeaderNoVerify_10000(t *testing.T) {
 		fuzzer.Fuzz(block)
 		s, err := v1.InitializeFromProtoUnsafe(state)
 		require.NoError(t, err)
-		_, err = ProcessBlockHeaderNoVerify(s, block.Slot, block.ProposerIndex, block.ParentRoot, []byte{})
+		_, err = ProcessBlockHeaderNoVerify(context.Background(), s, block.Slot, block.ProposerIndex, block.ParentRoot, []byte{})
 		_ = err
 	}
 }

beacon-chain/core/blocks/block_regression_test.go

@@ -6,7 +6,7 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	v "github.com/prysmaticlabs/prysm/beacon-chain/core/validators"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -44,9 +44,9 @@ func TestProcessAttesterSlashings_RegressionSlashableIndices(t *testing.T) {
 		AttestingIndices: setA,
 		Signature:        make([]byte, 96),
 	}
-	domain, err := helpers.Domain(beaconState.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, beaconState.GenesisValidatorRoot())
+	domain, err := signing.Domain(beaconState.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, beaconState.GenesisValidatorRoot())
 	require.NoError(t, err)
-	signingRoot, err := helpers.ComputeSigningRoot(att1.Data, domain)
+	signingRoot, err := signing.ComputeSigningRoot(att1.Data, domain)
 	require.NoError(t, err, "Could not get signing root of beacon block header")
 	var aggSigs []bls.Signature
 	for _, index := range setA {
@@ -64,7 +64,7 @@ func TestProcessAttesterSlashings_RegressionSlashableIndices(t *testing.T) {
 		AttestingIndices: setB,
 		Signature:        make([]byte, 96),
 	}
-	signingRoot, err = helpers.ComputeSigningRoot(att2.Data, domain)
+	signingRoot, err = signing.ComputeSigningRoot(att2.Data, domain)
 	assert.NoError(t, err, "Could not get signing root of beacon block header")
 	aggSigs = []bls.Signature{}
 	for _, index := range setB {

beacon-chain/core/blocks/deposit.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/container/trie"
@@ -99,7 +100,7 @@ func ProcessDeposits(
 // BatchVerifyDepositsSignatures batch verifies deposit signatures.
 func BatchVerifyDepositsSignatures(ctx context.Context, deposits []*ethpb.Deposit) (bool, error) {
 	var err error
-	domain, err := helpers.ComputeDomain(params.BeaconConfig().DomainDeposit, nil, nil)
+	domain, err := signing.ComputeDomain(params.BeaconConfig().DomainDeposit, nil, nil)
 	if err != nil {
 		return false, err
 	}
@@ -169,7 +170,7 @@ func ProcessDeposit(beaconState state.BeaconState, deposit *ethpb.Deposit, verif
 	index, ok := beaconState.ValidatorIndexByPubkey(bytesutil.ToBytes48(pubKey))
 	if !ok {
 		if verifySignature {
-			domain, err := helpers.ComputeDomain(params.BeaconConfig().DomainDeposit, nil, nil)
+			domain, err := signing.ComputeDomain(params.BeaconConfig().DomainDeposit, nil, nil)
 			if err != nil {
 				return nil, newValidator, err
 			}
@@ -266,7 +267,7 @@ func verifyDepositDataWithDomain(ctx context.Context, deps []*ethpb.Deposit, dom
 			WithdrawalCredentials: dep.Data.WithdrawalCredentials,
 			Amount:                dep.Data.Amount,
 		}
-		sr, err := helpers.ComputeSigningRoot(depositMessage, domain)
+		sr, err := signing.ComputeSigningRoot(depositMessage, domain)
 		if err != nil {
 			return err
 		}

beacon-chain/core/blocks/deposit_test.go

@@ -6,7 +6,7 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/container/trie"
@@ -142,7 +142,7 @@ func TestProcessDeposits_RepeatedDeposit_IncreasesValidatorBalance(t *testing.T)
 			Signature:             make([]byte, 96),
 		},
 	}
-	sr, err := helpers.ComputeSigningRoot(deposit.Data, bytesutil.ToBytes(3, 32))
+	sr, err := signing.ComputeSigningRoot(deposit.Data, bytesutil.ToBytes(3, 32))
 	require.NoError(t, err)
 	sig := sk.Sign(sr[:])
 	deposit.Data.Signature = sig.Marshal()
@@ -351,7 +351,7 @@ func TestProcessDeposit_RepeatedDeposit_IncreasesValidatorBalance(t *testing.T)
 			Signature:             make([]byte, 96),
 		},
 	}
-	sr, err := helpers.ComputeSigningRoot(deposit.Data, bytesutil.ToBytes(3, 32))
+	sr, err := signing.ComputeSigningRoot(deposit.Data, bytesutil.ToBytes(3, 32))
 	require.NoError(t, err)
 	sig := sk.Sign(sr[:])
 	deposit.Data.Signature = sig.Marshal()

beacon-chain/core/blocks/exit.go

@@ -6,12 +6,13 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	v "github.com/prysmaticlabs/prysm/beacon-chain/core/validators"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // ValidatorAlreadyExitedMsg defines a message saying that a validator has already exited.
@@ -44,7 +45,7 @@ var ValidatorCannotExitYetMsg = "validator has not been active long enough to ex
 //    # Initiate exit
 //    initiate_validator_exit(state, voluntary_exit.validator_index)
 func ProcessVoluntaryExits(
-	_ context.Context,
+	ctx context.Context,
 	beaconState state.BeaconState,
 	exits []*ethpb.SignedVoluntaryExit,
 ) (state.BeaconState, error) {
@@ -59,7 +60,7 @@ func ProcessVoluntaryExits(
 		if err := VerifyExitAndSignature(val, beaconState.Slot(), beaconState.Fork(), exit, beaconState.GenesisValidatorRoot()); err != nil {
 			return nil, errors.Wrapf(err, "could not verify exit %d", idx)
 		}
-		beaconState, err = v.InitiateValidatorExit(beaconState, exit.Exit.ValidatorIndex)
+		beaconState, err = v.InitiateValidatorExit(ctx, beaconState, exit.Exit.ValidatorIndex)
 		if err != nil {
 			return nil, err
 		}
@@ -102,13 +103,13 @@ func VerifyExitAndSignature(
 	if err := verifyExitConditions(validator, currentSlot, exit); err != nil {
 		return err
 	}
-	domain, err := helpers.Domain(fork, exit.Epoch, params.BeaconConfig().DomainVoluntaryExit, genesisRoot)
+	domain, err := signing.Domain(fork, exit.Epoch, params.BeaconConfig().DomainVoluntaryExit, genesisRoot)
 	if err != nil {
 		return err
 	}
 	valPubKey := validator.PublicKey()
-	if err := helpers.VerifySigningRoot(exit, valPubKey[:], signed.Signature, domain); err != nil {
-		return helpers.ErrSigFailedToVerify
+	if err := signing.VerifySigningRoot(exit, valPubKey[:], signed.Signature, domain); err != nil {
+		return signing.ErrSigFailedToVerify
 	}
 	return nil
 }
@@ -134,7 +135,7 @@ func VerifyExitAndSignature(
 //    # Initiate exit
 //    initiate_validator_exit(state, voluntary_exit.validator_index)
 func verifyExitConditions(validator state.ReadOnlyValidator, currentSlot types.Slot, exit *ethpb.VoluntaryExit) error {
-	currentEpoch := core.SlotToEpoch(currentSlot)
+	currentEpoch := slots.ToEpoch(currentSlot)
 	// Verify the validator is active.
 	if !helpers.IsActiveValidatorUsingTrie(validator, currentEpoch) {
 		return errors.New("non-active validator cannot exit")

beacon-chain/core/blocks/exit_test.go

@@ -5,9 +5,10 @@ import (
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -112,7 +113,7 @@ func TestProcessVoluntaryExits_AppliesCorrectStatus(t *testing.T) {
 	require.NoError(t, err)
 	val.PublicKey = priv.PublicKey().Marshal()
 	require.NoError(t, state.UpdateValidatorAtIndex(0, val))
-	exits[0].Signature, err = helpers.ComputeDomainAndSign(state, core.CurrentEpoch(state), exits[0].Exit, params.BeaconConfig().DomainVoluntaryExit, priv)
+	exits[0].Signature, err = signing.ComputeDomainAndSign(state, time.CurrentEpoch(state), exits[0].Exit, params.BeaconConfig().DomainVoluntaryExit, priv)
 	require.NoError(t, err)
 
 	b := util.NewBeaconBlock()

beacon-chain/core/blocks/header.go

@@ -39,7 +39,7 @@ import (
 //    proposer = state.validators[block.proposer_index]
 //    assert not proposer.slashed
 func ProcessBlockHeader(
-	_ context.Context,
+	ctx context.Context,
 	beaconState state.BeaconState,
 	block block.SignedBeaconBlock,
 ) (state.BeaconState, error) {
@@ -50,7 +50,7 @@ func ProcessBlockHeader(
 	if err != nil {
 		return nil, err
 	}
-	beaconState, err = ProcessBlockHeaderNoVerify(beaconState, block.Block().Slot(), block.Block().ProposerIndex(), block.Block().ParentRoot(), bodyRoot[:])
+	beaconState, err = ProcessBlockHeaderNoVerify(ctx, beaconState, block.Block().Slot(), block.Block().ProposerIndex(), block.Block().ParentRoot(), bodyRoot[:])
 	if err != nil {
 		return nil, err
 	}
@@ -92,6 +92,7 @@ func ProcessBlockHeader(
 //    proposer = state.validators[block.proposer_index]
 //    assert not proposer.slashed
 func ProcessBlockHeaderNoVerify(
+	ctx context.Context,
 	beaconState state.BeaconState,
 	slot types.Slot, proposerIndex types.ValidatorIndex,
 	parentRoot, bodyRoot []byte,
@@ -99,7 +100,7 @@ func ProcessBlockHeaderNoVerify(
 	if beaconState.Slot() != slot {
 		return nil, fmt.Errorf("state slot: %d is different than block slot: %d", beaconState.Slot(), slot)
 	}
-	idx, err := helpers.BeaconProposerIndex(beaconState)
+	idx, err := helpers.BeaconProposerIndex(ctx, beaconState)
 	if err != nil {
 		return nil, err
 	}

beacon-chain/core/blocks/header_test.go

@@ -5,9 +5,10 @@ import (
 	"io/ioutil"
 	"testing"
 
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	p2ptypes "github.com/prysmaticlabs/prysm/beacon-chain/p2p/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -47,20 +48,20 @@ func TestProcessBlockHeader_ImproperBlockSlot(t *testing.T) {
 	latestBlockSignedRoot, err := state.LatestBlockHeader().HashTreeRoot()
 	require.NoError(t, err)
 
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	priv, err := bls.RandKey()
 	require.NoError(t, err)
-	pID, err := helpers.BeaconProposerIndex(state)
+	pID, err := helpers.BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	block := util.NewBeaconBlock()
 	block.Block.ProposerIndex = pID
 	block.Block.Slot = 10
 	block.Block.Body.RandaoReveal = bytesutil.PadTo([]byte{'A', 'B', 'C'}, 96)
 	block.Block.ParentRoot = latestBlockSignedRoot[:]
-	block.Signature, err = helpers.ComputeDomainAndSign(state, currentEpoch, block.Block, params.BeaconConfig().DomainBeaconProposer, priv)
+	block.Signature, err = signing.ComputeDomainAndSign(state, currentEpoch, block.Block, params.BeaconConfig().DomainBeaconProposer, priv)
 	require.NoError(t, err)
 
-	proposerIdx, err := helpers.BeaconProposerIndex(state)
+	proposerIdx, err := helpers.BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	validators[proposerIdx].Slashed = false
 	validators[proposerIdx].PublicKey = priv.PublicKey().Marshal()
@@ -82,7 +83,7 @@ func TestProcessBlockHeader_WrongProposerSig(t *testing.T) {
 	lbhdr, err := beaconState.LatestBlockHeader().HashTreeRoot()
 	require.NoError(t, err)
 
-	proposerIdx, err := helpers.BeaconProposerIndex(beaconState)
+	proposerIdx, err := helpers.BeaconProposerIndex(context.Background(), beaconState)
 	require.NoError(t, err)
 
 	block := util.NewBeaconBlock()
@@ -90,7 +91,7 @@ func TestProcessBlockHeader_WrongProposerSig(t *testing.T) {
 	block.Block.Slot = 10
 	block.Block.Body.RandaoReveal = bytesutil.PadTo([]byte{'A', 'B', 'C'}, 96)
 	block.Block.ParentRoot = lbhdr[:]
-	block.Signature, err = helpers.ComputeDomainAndSign(beaconState, 0, block.Block, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx+1])
+	block.Signature, err = signing.ComputeDomainAndSign(beaconState, 0, block.Block, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx+1])
 	require.NoError(t, err)
 
 	_, err = blocks.ProcessBlockHeader(context.Background(), beaconState, wrapper.WrappedPhase0SignedBeaconBlock(block))
@@ -119,12 +120,12 @@ func TestProcessBlockHeader_DifferentSlots(t *testing.T) {
 
 	lbhsr, err := state.LatestBlockHeader().HashTreeRoot()
 	require.NoError(t, err)
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 
 	priv, err := bls.RandKey()
 	require.NoError(t, err)
 	sszBytes := p2ptypes.SSZBytes("hello")
-	blockSig, err := helpers.ComputeDomainAndSign(state, currentEpoch, &sszBytes, params.BeaconConfig().DomainBeaconProposer, priv)
+	blockSig, err := signing.ComputeDomainAndSign(state, currentEpoch, &sszBytes, params.BeaconConfig().DomainBeaconProposer, priv)
 	require.NoError(t, err)
 	validators[5896].PublicKey = priv.PublicKey().Marshal()
 	block := util.HydrateSignedBeaconBlock(&ethpb.SignedBeaconBlock{
@@ -158,14 +159,14 @@ func TestProcessBlockHeader_PreviousBlockRootNotSignedRoot(t *testing.T) {
 	bh := state.LatestBlockHeader()
 	bh.Slot = 9
 	require.NoError(t, state.SetLatestBlockHeader(bh))
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	priv, err := bls.RandKey()
 	require.NoError(t, err)
 	sszBytes := p2ptypes.SSZBytes("hello")
-	blockSig, err := helpers.ComputeDomainAndSign(state, currentEpoch, &sszBytes, params.BeaconConfig().DomainBeaconProposer, priv)
+	blockSig, err := signing.ComputeDomainAndSign(state, currentEpoch, &sszBytes, params.BeaconConfig().DomainBeaconProposer, priv)
 	require.NoError(t, err)
 	validators[5896].PublicKey = priv.PublicKey().Marshal()
-	pID, err := helpers.BeaconProposerIndex(state)
+	pID, err := helpers.BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	block := util.NewBeaconBlock()
 	block.Block.Slot = 10
@@ -199,15 +200,15 @@ func TestProcessBlockHeader_SlashedProposer(t *testing.T) {
 	require.NoError(t, state.SetLatestBlockHeader(bh))
 	parentRoot, err := state.LatestBlockHeader().HashTreeRoot()
 	require.NoError(t, err)
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	priv, err := bls.RandKey()
 	require.NoError(t, err)
 	sszBytes := p2ptypes.SSZBytes("hello")
-	blockSig, err := helpers.ComputeDomainAndSign(state, currentEpoch, &sszBytes, params.BeaconConfig().DomainBeaconProposer, priv)
+	blockSig, err := signing.ComputeDomainAndSign(state, currentEpoch, &sszBytes, params.BeaconConfig().DomainBeaconProposer, priv)
 	require.NoError(t, err)
 
 	validators[12683].PublicKey = priv.PublicKey().Marshal()
-	pID, err := helpers.BeaconProposerIndex(state)
+	pID, err := helpers.BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	block := util.NewBeaconBlock()
 	block.Block.Slot = 10
@@ -243,22 +244,22 @@ func TestProcessBlockHeader_OK(t *testing.T) {
 	latestBlockSignedRoot, err := state.LatestBlockHeader().HashTreeRoot()
 	require.NoError(t, err)
 
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	priv, err := bls.RandKey()
 	require.NoError(t, err)
-	pID, err := helpers.BeaconProposerIndex(state)
+	pID, err := helpers.BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	block := util.NewBeaconBlock()
 	block.Block.ProposerIndex = pID
 	block.Block.Slot = 10
 	block.Block.Body.RandaoReveal = bytesutil.PadTo([]byte{'A', 'B', 'C'}, 96)
 	block.Block.ParentRoot = latestBlockSignedRoot[:]
-	block.Signature, err = helpers.ComputeDomainAndSign(state, currentEpoch, block.Block, params.BeaconConfig().DomainBeaconProposer, priv)
+	block.Signature, err = signing.ComputeDomainAndSign(state, currentEpoch, block.Block, params.BeaconConfig().DomainBeaconProposer, priv)
 	require.NoError(t, err)
 	bodyRoot, err := block.Block.Body.HashTreeRoot()
 	require.NoError(t, err, "Failed to hash block bytes got")
 
-	proposerIdx, err := helpers.BeaconProposerIndex(state)
+	proposerIdx, err := helpers.BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	validators[proposerIdx].Slashed = false
 	validators[proposerIdx].PublicKey = priv.PublicKey().Marshal()
@@ -302,19 +303,19 @@ func TestBlockSignatureSet_OK(t *testing.T) {
 	latestBlockSignedRoot, err := state.LatestBlockHeader().HashTreeRoot()
 	require.NoError(t, err)
 
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	priv, err := bls.RandKey()
 	require.NoError(t, err)
-	pID, err := helpers.BeaconProposerIndex(state)
+	pID, err := helpers.BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	block := util.NewBeaconBlock()
 	block.Block.Slot = 10
 	block.Block.ProposerIndex = pID
 	block.Block.Body.RandaoReveal = bytesutil.PadTo([]byte{'A', 'B', 'C'}, 96)
 	block.Block.ParentRoot = latestBlockSignedRoot[:]
-	block.Signature, err = helpers.ComputeDomainAndSign(state, currentEpoch, block.Block, params.BeaconConfig().DomainBeaconProposer, priv)
+	block.Signature, err = signing.ComputeDomainAndSign(state, currentEpoch, block.Block, params.BeaconConfig().DomainBeaconProposer, priv)
 	require.NoError(t, err)
-	proposerIdx, err := helpers.BeaconProposerIndex(state)
+	proposerIdx, err := helpers.BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	validators[proposerIdx].Slashed = false
 	validators[proposerIdx].PublicKey = priv.PublicKey().Marshal()

beacon-chain/core/blocks/proposer_slashing.go

@@ -6,16 +6,18 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/runtime/version"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	"google.golang.org/protobuf/proto"
 )
 
-type slashValidatorFunc func(st state.BeaconState, vid types.ValidatorIndex, penaltyQuotient, proposerRewardQuotient uint64) (state.BeaconState, error)
+type slashValidatorFunc func(ctx context.Context, st state.BeaconState, vid types.ValidatorIndex, penaltyQuotient, proposerRewardQuotient uint64) (state.BeaconState, error)
 
 // ProcessProposerSlashings is one of the operations performed
 // on each processed beacon block to slash proposers based on
@@ -43,7 +45,7 @@ type slashValidatorFunc func(st state.BeaconState, vid types.ValidatorIndex, pen
 //
 //    slash_validator(state, header_1.proposer_index)
 func ProcessProposerSlashings(
-	_ context.Context,
+	ctx context.Context,
 	beaconState state.BeaconState,
 	slashings []*ethpb.ProposerSlashing,
 	slashFunc slashValidatorFunc,
@@ -61,7 +63,7 @@ func ProcessProposerSlashings(
 		if beaconState.Version() == version.Altair {
 			slashingQuotient = cfg.MinSlashingPenaltyQuotientAltair
 		}
-		beaconState, err = slashFunc(beaconState, slashing.Header_1.Header.ProposerIndex, slashingQuotient, cfg.ProposerRewardQuotient)
+		beaconState, err = slashFunc(ctx, beaconState, slashing.Header_1.Header.ProposerIndex, slashingQuotient, cfg.ProposerRewardQuotient)
 		if err != nil {
 			return nil, errors.Wrapf(err, "could not slash proposer index %d", slashing.Header_1.Header.ProposerIndex)
 		}
@@ -71,7 +73,7 @@ func ProcessProposerSlashings(
 
 // VerifyProposerSlashing verifies that the data provided from slashing is valid.
 func VerifyProposerSlashing(
-	beaconState state.BeaconState,
+	beaconState state.ReadOnlyBeaconState,
 	slashing *ethpb.ProposerSlashing,
 ) error {
 	if slashing.Header_1 == nil || slashing.Header_1.Header == nil || slashing.Header_2 == nil || slashing.Header_2.Header == nil {
@@ -92,12 +94,12 @@ func VerifyProposerSlashing(
 	if err != nil {
 		return err
 	}
-	if !helpers.IsSlashableValidatorUsingTrie(proposer, core.CurrentEpoch(beaconState)) {
+	if !helpers.IsSlashableValidatorUsingTrie(proposer, time.CurrentEpoch(beaconState)) {
 		return fmt.Errorf("validator with key %#x is not slashable", proposer.PublicKey())
 	}
 	headers := []*ethpb.SignedBeaconBlockHeader{slashing.Header_1, slashing.Header_2}
 	for _, header := range headers {
-		if err := helpers.ComputeDomainVerifySigningRoot(beaconState, pIdx, core.SlotToEpoch(hSlot),
+		if err := signing.ComputeDomainVerifySigningRoot(beaconState, pIdx, slots.ToEpoch(hSlot),
 			header.Header, params.BeaconConfig().DomainBeaconProposer, header.Signature); err != nil {
 			return errors.Wrap(err, "could not verify beacon block header")
 		}

beacon-chain/core/blocks/proposer_slashing_test.go

@@ -6,9 +6,8 @@ import (
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	v "github.com/prysmaticlabs/prysm/beacon-chain/core/validators"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
@@ -19,6 +18,7 @@ import (
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 func TestProcessProposerSlashings_UnmatchedHeaderSlots(t *testing.T) {
@@ -150,7 +150,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatus(t *testing.T) {
 		}),
 	}
 	var err error
-	header1.Signature, err = helpers.ComputeDomainAndSign(beaconState, 0, header1.Header, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx])
+	header1.Signature, err = signing.ComputeDomainAndSign(beaconState, 0, header1.Header, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx])
 	require.NoError(t, err)
 
 	header2 := util.HydrateSignedBeaconHeader(&ethpb.SignedBeaconBlockHeader{
@@ -159,7 +159,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatus(t *testing.T) {
 			StateRoot:     bytesutil.PadTo([]byte("B"), 32),
 		},
 	})
-	header2.Signature, err = helpers.ComputeDomainAndSign(beaconState, 0, header2.Header, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx])
+	header2.Signature, err = signing.ComputeDomainAndSign(beaconState, 0, header2.Header, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx])
 	require.NoError(t, err)
 
 	slashings := []*ethpb.ProposerSlashing{
@@ -198,7 +198,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatusAltair(t *testing.T) {
 		}),
 	}
 	var err error
-	header1.Signature, err = helpers.ComputeDomainAndSign(beaconState, 0, header1.Header, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx])
+	header1.Signature, err = signing.ComputeDomainAndSign(beaconState, 0, header1.Header, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx])
 	require.NoError(t, err)
 
 	header2 := util.HydrateSignedBeaconHeader(&ethpb.SignedBeaconBlockHeader{
@@ -207,7 +207,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatusAltair(t *testing.T) {
 			StateRoot:     bytesutil.PadTo([]byte("B"), 32),
 		},
 	})
-	header2.Signature, err = helpers.ComputeDomainAndSign(beaconState, 0, header2.Header, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx])
+	header2.Signature, err = signing.ComputeDomainAndSign(beaconState, 0, header2.Header, params.BeaconConfig().DomainBeaconProposer, privKeys[proposerIdx])
 	require.NoError(t, err)
 
 	slashings := []*ethpb.ProposerSlashing{
@@ -329,15 +329,15 @@ func TestVerifyProposerSlashing(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 
 			sk := sks[tt.args.slashing.Header_1.Header.ProposerIndex]
-			d, err := helpers.Domain(tt.args.beaconState.Fork(), core.SlotToEpoch(tt.args.slashing.Header_1.Header.Slot), params.BeaconConfig().DomainBeaconProposer, tt.args.beaconState.GenesisValidatorRoot())
+			d, err := signing.Domain(tt.args.beaconState.Fork(), slots.ToEpoch(tt.args.slashing.Header_1.Header.Slot), params.BeaconConfig().DomainBeaconProposer, tt.args.beaconState.GenesisValidatorRoot())
 			require.NoError(t, err)
 			if tt.args.slashing.Header_1.Signature == nil {
-				sr, err := helpers.ComputeSigningRoot(tt.args.slashing.Header_1.Header, d)
+				sr, err := signing.ComputeSigningRoot(tt.args.slashing.Header_1.Header, d)
 				require.NoError(t, err)
 				tt.args.slashing.Header_1.Signature = sk.Sign(sr[:]).Marshal()
 			}
 			if tt.args.slashing.Header_2.Signature == nil {
-				sr, err := helpers.ComputeSigningRoot(tt.args.slashing.Header_2.Header, d)
+				sr, err := signing.ComputeSigningRoot(tt.args.slashing.Header_2.Header, d)
 				require.NoError(t, err)
 				tt.args.slashing.Header_2.Signature = sk.Sign(sr[:]).Marshal()
 			}

beacon-chain/core/blocks/randao.go

@@ -4,12 +4,12 @@ import (
 	"context"
 
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/hash"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/block"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // ProcessRandao checks the block proposer's
@@ -27,7 +27,7 @@ import (
 //    mix = xor(get_randao_mix(state, epoch), hash(body.randao_reveal))
 //    state.randao_mixes[epoch % EPOCHS_PER_HISTORICAL_VECTOR] = mix
 func ProcessRandao(
-	_ context.Context,
+	ctx context.Context,
 	beaconState state.BeaconState,
 	b block.SignedBeaconBlock,
 ) (state.BeaconState, error) {
@@ -35,7 +35,7 @@ func ProcessRandao(
 		return nil, err
 	}
 	body := b.Block().Body()
-	buf, proposerPub, domain, err := randaoSigningData(beaconState)
+	buf, proposerPub, domain, err := randaoSigningData(ctx, beaconState)
 	if err != nil {
 		return nil, err
 	}
@@ -63,7 +63,7 @@ func ProcessRandaoNoVerify(
 	beaconState state.BeaconState,
 	randaoReveal []byte,
 ) (state.BeaconState, error) {
-	currentEpoch := core.SlotToEpoch(beaconState.Slot())
+	currentEpoch := slots.ToEpoch(beaconState.Slot())
 	// If block randao passed verification, we XOR the state's latest randao mix with the block's
 	// randao and update the state's corresponding latest randao mix value.
 	latestMixesLength := params.BeaconConfig().EpochsPerHistoricalVector

beacon-chain/core/blocks/randao_test.go

@@ -6,9 +6,10 @@ import (
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/config/params"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/wrapper"
@@ -20,12 +21,12 @@ import (
 func TestProcessRandao_IncorrectProposerFailsVerification(t *testing.T) {
 	beaconState, privKeys := util.DeterministicGenesisState(t, 100)
 	// We fetch the proposer's index as that is whom the RANDAO will be verified against.
-	proposerIdx, err := helpers.BeaconProposerIndex(beaconState)
+	proposerIdx, err := helpers.BeaconProposerIndex(context.Background(), beaconState)
 	require.NoError(t, err)
 	epoch := types.Epoch(0)
 	buf := make([]byte, 32)
 	binary.LittleEndian.PutUint64(buf, uint64(epoch))
-	domain, err := helpers.Domain(beaconState.Fork(), epoch, params.BeaconConfig().DomainRandao, beaconState.GenesisValidatorRoot())
+	domain, err := signing.Domain(beaconState.Fork(), epoch, params.BeaconConfig().DomainRandao, beaconState.GenesisValidatorRoot())
 	require.NoError(t, err)
 	root, err := (&ethpb.SigningData{ObjectRoot: buf, Domain: domain}).HashTreeRoot()
 	require.NoError(t, err)
@@ -46,7 +47,7 @@ func TestProcessRandao_IncorrectProposerFailsVerification(t *testing.T) {
 func TestProcessRandao_SignatureVerifiesAndUpdatesLatestStateMixes(t *testing.T) {
 	beaconState, privKeys := util.DeterministicGenesisState(t, 100)
 
-	epoch := core.CurrentEpoch(beaconState)
+	epoch := time.CurrentEpoch(beaconState)
 	epochSignature, err := util.RandaoReveal(beaconState, epoch, privKeys)
 	require.NoError(t, err)
 
@@ -63,7 +64,7 @@ func TestProcessRandao_SignatureVerifiesAndUpdatesLatestStateMixes(t *testing.T)
 		wrapper.WrappedPhase0SignedBeaconBlock(b),
 	)
 	require.NoError(t, err, "Unexpected error processing block randao")
-	currentEpoch := core.CurrentEpoch(beaconState)
+	currentEpoch := time.CurrentEpoch(beaconState)
 	mix := newState.RandaoMixes()[currentEpoch%params.BeaconConfig().EpochsPerHistoricalVector]
 	assert.DeepNotEqual(t, params.BeaconConfig().ZeroHash[:], mix, "Expected empty signature to be overwritten by randao reveal")
 }
@@ -71,7 +72,7 @@ func TestProcessRandao_SignatureVerifiesAndUpdatesLatestStateMixes(t *testing.T)
 func TestRandaoSignatureSet_OK(t *testing.T) {
 	beaconState, privKeys := util.DeterministicGenesisState(t, 100)
 
-	epoch := core.CurrentEpoch(beaconState)
+	epoch := time.CurrentEpoch(beaconState)
 	epochSignature, err := util.RandaoReveal(beaconState, epoch, privKeys)
 	require.NoError(t, err)
 
@@ -81,7 +82,7 @@ func TestRandaoSignatureSet_OK(t *testing.T) {
 		},
 	}
 
-	set, err := blocks.RandaoSignatureSet(beaconState, block.Body.RandaoReveal)
+	set, err := blocks.RandaoSignatureSet(context.Background(), beaconState, block.Body.RandaoReveal)
 	require.NoError(t, err)
 	verified, err := set.Verify()
 	require.NoError(t, err)

beacon-chain/core/blocks/signature.go

@@ -6,8 +6,8 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -15,6 +15,7 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/block"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // retrieves the signature set from the raw data, public key,signature and domain provided.
@@ -56,7 +57,7 @@ func verifySignature(signedData, pub, signature, domain []byte) error {
 		return err
 	}
 	if !rSig.Verify(publicKey, root[:]) {
-		return helpers.ErrSigFailedToVerify
+		return signing.ErrSigFailedToVerify
 	}
 	return nil
 }
@@ -66,8 +67,8 @@ func VerifyBlockSignature(beaconState state.ReadOnlyBeaconState,
 	proposerIndex types.ValidatorIndex,
 	sig []byte,
 	rootFunc func() ([32]byte, error)) error {
-	currentEpoch := core.SlotToEpoch(beaconState.Slot())
-	domain, err := helpers.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
+	currentEpoch := slots.ToEpoch(beaconState.Slot())
+	domain, err := signing.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
 	if err != nil {
 		return err
 	}
@@ -76,19 +77,34 @@ func VerifyBlockSignature(beaconState state.ReadOnlyBeaconState,
 		return err
 	}
 	proposerPubKey := proposer.PublicKey
-	return helpers.VerifyBlockSigningRoot(proposerPubKey, sig, domain, rootFunc)
+	return signing.VerifyBlockSigningRoot(proposerPubKey, sig, domain, rootFunc)
+}
+
+// VerifyBlockHeaderSignature verifies the proposer signature of a beacon block header.
+func VerifyBlockHeaderSignature(beaconState state.BeaconState, header *ethpb.SignedBeaconBlockHeader) error {
+	currentEpoch := slots.ToEpoch(beaconState.Slot())
+	domain, err := signing.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
+	if err != nil {
+		return err
+	}
+	proposer, err := beaconState.ValidatorAtIndex(header.Header.ProposerIndex)
+	if err != nil {
+		return err
+	}
+	proposerPubKey := proposer.PublicKey
+	return signing.VerifyBlockHeaderSigningRoot(header.Header, proposerPubKey, header.Signature, domain)
 }
 
 // VerifyBlockSignatureUsingCurrentFork verifies the proposer signature of a beacon block. This differs
 // from the above method by not using fork data from the state and instead retrieving it
 // via the respective epoch.
 func VerifyBlockSignatureUsingCurrentFork(beaconState state.ReadOnlyBeaconState, blk block.SignedBeaconBlock) error {
-	currentEpoch := core.SlotToEpoch(blk.Block().Slot())
+	currentEpoch := slots.ToEpoch(blk.Block().Slot())
 	fork, err := forks.Fork(currentEpoch)
 	if err != nil {
 		return err
 	}
-	domain, err := helpers.Domain(fork, currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
+	domain, err := signing.Domain(fork, currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
 	if err != nil {
 		return err
 	}
@@ -97,7 +113,7 @@ func VerifyBlockSignatureUsingCurrentFork(beaconState state.ReadOnlyBeaconState,
 		return err
 	}
 	proposerPubKey := proposer.PublicKey
-	return helpers.VerifyBlockSigningRoot(proposerPubKey, blk.Signature(), domain, blk.Block().HashTreeRoot)
+	return signing.VerifyBlockSigningRoot(proposerPubKey, blk.Signature(), domain, blk.Block().HashTreeRoot)
 }
 
 // BlockSignatureSet retrieves the block signature set from the provided block and its corresponding state.
@@ -105,8 +121,8 @@ func BlockSignatureSet(beaconState state.ReadOnlyBeaconState,
 	proposerIndex types.ValidatorIndex,
 	sig []byte,
 	rootFunc func() ([32]byte, error)) (*bls.SignatureSet, error) {
-	currentEpoch := core.SlotToEpoch(beaconState.Slot())
-	domain, err := helpers.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
+	currentEpoch := slots.ToEpoch(beaconState.Slot())
+	domain, err := signing.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorRoot())
 	if err != nil {
 		return nil, err
 	}
@@ -115,15 +131,17 @@ func BlockSignatureSet(beaconState state.ReadOnlyBeaconState,
 		return nil, err
 	}
 	proposerPubKey := proposer.PublicKey
-	return helpers.BlockSignatureSet(proposerPubKey, sig, domain, rootFunc)
+	return signing.BlockSignatureSet(proposerPubKey, sig, domain, rootFunc)
 }
 
 // RandaoSignatureSet retrieves the relevant randao specific signature set object
 // from a block and its corresponding state.
-func RandaoSignatureSet(beaconState state.ReadOnlyBeaconState,
+func RandaoSignatureSet(
+	ctx context.Context,
+	beaconState state.ReadOnlyBeaconState,
 	reveal []byte,
 ) (*bls.SignatureSet, error) {
-	buf, proposerPub, domain, err := randaoSigningData(beaconState)
+	buf, proposerPub, domain, err := randaoSigningData(ctx, beaconState)
 	if err != nil {
 		return nil, err
 	}
@@ -135,18 +153,18 @@ func RandaoSignatureSet(beaconState state.ReadOnlyBeaconState,
 }
 
 // retrieves the randao related signing data from the state.
-func randaoSigningData(beaconState state.ReadOnlyBeaconState) ([]byte, []byte, []byte, error) {
-	proposerIdx, err := helpers.BeaconProposerIndex(beaconState)
+func randaoSigningData(ctx context.Context, beaconState state.ReadOnlyBeaconState) ([]byte, []byte, []byte, error) {
+	proposerIdx, err := helpers.BeaconProposerIndex(ctx, beaconState)
 	if err != nil {
 		return nil, nil, nil, errors.Wrap(err, "could not get beacon proposer index")
 	}
 	proposerPub := beaconState.PubkeyAtIndex(proposerIdx)
 
-	currentEpoch := core.SlotToEpoch(beaconState.Slot())
+	currentEpoch := slots.ToEpoch(beaconState.Slot())
 	buf := make([]byte, 32)
 	binary.LittleEndian.PutUint64(buf, uint64(currentEpoch))
 
-	domain, err := helpers.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainRandao, beaconState.GenesisValidatorRoot())
+	domain, err := signing.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainRandao, beaconState.GenesisValidatorRoot())
 	if err != nil {
 		return nil, nil, nil, err
 	}
@@ -169,7 +187,7 @@ func createAttestationSignatureSet(
 	msgs := make([][32]byte, len(atts))
 	for i, a := range atts {
 		sigs[i] = a.Signature
-		c, err := helpers.BeaconCommitteeFromState(beaconState, a.Data.Slot, a.Data.CommitteeIndex)
+		c, err := helpers.BeaconCommitteeFromState(ctx, beaconState, a.Data.Slot, a.Data.CommitteeIndex)
 		if err != nil {
 			return nil, err
 		}
@@ -192,7 +210,7 @@ func createAttestationSignatureSet(
 		}
 		pks[i] = aggP
 
-		root, err := helpers.ComputeSigningRoot(ia.Data, domain)
+		root, err := signing.ComputeSigningRoot(ia.Data, domain)
 		if err != nil {
 			return nil, errors.Wrap(err, "could not get signing root of object")
 		}
@@ -220,7 +238,7 @@ func AttestationSignatureSet(ctx context.Context, beaconState state.ReadOnlyBeac
 	var preForkAtts []*ethpb.Attestation
 	var postForkAtts []*ethpb.Attestation
 	for _, a := range atts {
-		if core.SlotToEpoch(a.Data.Slot) < fork.Epoch {
+		if slots.ToEpoch(a.Data.Slot) < fork.Epoch {
 			preForkAtts = append(preForkAtts, a)
 		} else {
 			postForkAtts = append(postForkAtts, a)
@@ -230,7 +248,7 @@ func AttestationSignatureSet(ctx context.Context, beaconState state.ReadOnlyBeac
 
 	// Check attestations from before the fork.
 	if fork.Epoch > 0 && len(preForkAtts) > 0 { // Check to prevent underflow and there is valid attestations to create sig set.
-		prevDomain, err := helpers.Domain(fork, fork.Epoch-1, dt, gvr)
+		prevDomain, err := signing.Domain(fork, fork.Epoch-1, dt, gvr)
 		if err != nil {
 			return nil, err
 		}
@@ -249,7 +267,7 @@ func AttestationSignatureSet(ctx context.Context, beaconState state.ReadOnlyBeac
 
 	if len(postForkAtts) > 0 {
 		// Then check attestations from after the fork.
-		currDomain, err := helpers.Domain(fork, fork.Epoch, dt, gvr)
+		currDomain, err := signing.Domain(fork, fork.Epoch, dt, gvr)
 		if err != nil {
 			return nil, err
 		}

beacon-chain/core/blocks/signature_test.go

@@ -4,8 +4,9 @@ import (
 	"testing"
 
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
 	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/crypto/bls"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/wrapper"
@@ -14,6 +15,53 @@ import (
 	"github.com/prysmaticlabs/prysm/testing/util"
 )
 
+func TestVerifyBlockHeaderSignature(t *testing.T) {
+	beaconState, err := util.NewBeaconState()
+	require.NoError(t, err)
+
+	privKey, err := bls.RandKey()
+	require.NoError(t, err)
+	validators := make([]*ethpb.Validator, 1)
+	validators[0] = &ethpb.Validator{
+		PublicKey:             privKey.PublicKey().Marshal(),
+		WithdrawalCredentials: make([]byte, 32),
+		EffectiveBalance:      params.BeaconConfig().MaxEffectiveBalance,
+	}
+	err = beaconState.SetValidators(validators)
+	require.NoError(t, err)
+
+	// Sign the block header.
+	blockHeader := util.HydrateSignedBeaconHeader(&ethpb.SignedBeaconBlockHeader{
+		Header: &ethpb.BeaconBlockHeader{
+			Slot:          0,
+			ProposerIndex: 0,
+		},
+	})
+	domain, err := signing.Domain(
+		beaconState.Fork(),
+		0,
+		params.BeaconConfig().DomainBeaconProposer,
+		beaconState.GenesisValidatorRoot(),
+	)
+	require.NoError(t, err)
+	htr, err := blockHeader.Header.HashTreeRoot()
+	require.NoError(t, err)
+	container := &ethpb.SigningData{
+		ObjectRoot: htr[:],
+		Domain:     domain,
+	}
+	require.NoError(t, err)
+	signingRoot, err := container.HashTreeRoot()
+	require.NoError(t, err)
+
+	// Set the signature in the block header.
+	blockHeader.Signature = privKey.Sign(signingRoot[:]).Marshal()
+
+	// Sig should verify.
+	err = blocks.VerifyBlockHeaderSignature(beaconState, blockHeader)
+	require.NoError(t, err)
+}
+
 func TestVerifyBlockSignatureUsingCurrentFork(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	bCfg := params.BeaconConfig()
@@ -29,9 +77,9 @@ func TestVerifyBlockSignatureUsingCurrentFork(t *testing.T) {
 		CurrentVersion:  params.BeaconConfig().AltairForkVersion,
 		PreviousVersion: params.BeaconConfig().GenesisForkVersion,
 	}
-	domain, err := helpers.Domain(fData, 100, params.BeaconConfig().DomainBeaconProposer, bState.GenesisValidatorRoot())
+	domain, err := signing.Domain(fData, 100, params.BeaconConfig().DomainBeaconProposer, bState.GenesisValidatorRoot())
 	assert.NoError(t, err)
-	rt, err := helpers.ComputeSigningRoot(altairBlk.Block, domain)
+	rt, err := signing.ComputeSigningRoot(altairBlk.Block, domain)
 	assert.NoError(t, err)
 	sig := keys[0].Sign(rt[:]).Marshal()
 	altairBlk.Signature = sig

beacon-chain/core/epoch/BUILD.bazel

@@ -9,8 +9,8 @@ go_library(
         "//testing/spectest:__subpackages__",
     ],
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/validators:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/features:go_default_library",
@@ -32,8 +32,8 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/v1:go_default_library",
         "//config/params:go_default_library",

beacon-chain/core/epoch/epoch_processing.go

@@ -5,13 +5,14 @@
 package epoch
 
 import (
+	"context"
 	"fmt"
 	"sort"
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/validators"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/features"
@@ -55,8 +56,8 @@ func (s sortableIndices) Less(i, j int) bool {
 //    Note: ``get_total_balance`` returns ``EFFECTIVE_BALANCE_INCREMENT`` Gwei minimum to avoid divisions by zero.
 //    """
 //    return get_total_balance(state, get_unslashed_attesting_indices(state, attestations))
-func AttestingBalance(state state.ReadOnlyBeaconState, atts []*ethpb.PendingAttestation) (uint64, error) {
-	indices, err := UnslashedAttestingIndices(state, atts)
+func AttestingBalance(ctx context.Context, state state.ReadOnlyBeaconState, atts []*ethpb.PendingAttestation) (uint64, error) {
+	indices, err := UnslashedAttestingIndices(ctx, state, atts)
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get attesting indices")
 	}
@@ -86,12 +87,12 @@ func AttestingBalance(state state.ReadOnlyBeaconState, atts []*ethpb.PendingAtte
 //    for index in activation_queue[:get_validator_churn_limit(state)]:
 //        validator = state.validators[index]
 //        validator.activation_epoch = compute_activation_exit_epoch(get_current_epoch(state))
-func ProcessRegistryUpdates(state state.BeaconState) (state.BeaconState, error) {
-	currentEpoch := core.CurrentEpoch(state)
+func ProcessRegistryUpdates(ctx context.Context, state state.BeaconState) (state.BeaconState, error) {
+	currentEpoch := time.CurrentEpoch(state)
 	vals := state.Validators()
 	var err error
 	ejectionBal := params.BeaconConfig().EjectionBalance
-	activationEligibilityEpoch := core.CurrentEpoch(state) + 1
+	activationEligibilityEpoch := time.CurrentEpoch(state) + 1
 	for idx, validator := range vals {
 		// Process the validators for activation eligibility.
 		if helpers.IsEligibleForActivationQueue(validator) {
@@ -105,7 +106,7 @@ func ProcessRegistryUpdates(state state.BeaconState) (state.BeaconState, error)
 		isActive := helpers.IsActiveValidator(validator, currentEpoch)
 		belowEjectionBalance := validator.EffectiveBalance <= ejectionBal
 		if isActive && belowEjectionBalance {
-			state, err = validators.InitiateValidatorExit(state, types.ValidatorIndex(idx))
+			state, err = validators.InitiateValidatorExit(ctx, state, types.ValidatorIndex(idx))
 			if err != nil {
 				return nil, errors.Wrapf(err, "could not initiate exit for validator %d", idx)
 			}
@@ -124,7 +125,7 @@ func ProcessRegistryUpdates(state state.BeaconState) (state.BeaconState, error)
 
 	// Only activate just enough validators according to the activation churn limit.
 	limit := uint64(len(activationQ))
-	activeValidatorCount, err := helpers.ActiveValidatorCount(state, currentEpoch)
+	activeValidatorCount, err := helpers.ActiveValidatorCount(ctx, state, currentEpoch)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get active validator count")
 	}
@@ -166,7 +167,7 @@ func ProcessRegistryUpdates(state state.BeaconState) (state.BeaconState, error)
 //            penalty = penalty_numerator // total_balance * increment
 //            decrease_balance(state, ValidatorIndex(index), penalty)
 func ProcessSlashings(state state.BeaconState, slashingMultiplier uint64) (state.BeaconState, error) {
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	totalBalance, err := helpers.TotalActiveBalance(state)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get total active balance")
@@ -179,7 +180,10 @@ func ProcessSlashings(state state.BeaconState, slashingMultiplier uint64) (state
 	slashings := state.Slashings()
 	totalSlashing := uint64(0)
 	for _, slashing := range slashings {
-		totalSlashing += slashing
+		totalSlashing, err = math.Add64(totalSlashing, slashing)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	// a callback is used here to apply the following actions  to all validators
@@ -210,7 +214,7 @@ func ProcessSlashings(state state.BeaconState, slashingMultiplier uint64) (state
 //    if next_epoch % EPOCHS_PER_ETH1_VOTING_PERIOD == 0:
 //        state.eth1_data_votes = []
 func ProcessEth1DataReset(state state.BeaconState) (state.BeaconState, error) {
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	nextEpoch := currentEpoch + 1
 
 	// Reset ETH1 data votes.
@@ -308,7 +312,7 @@ func ProcessEffectiveBalanceUpdates(state state.BeaconState) (state.BeaconState,
 //    # Reset slashings
 //    state.slashings[next_epoch % EPOCHS_PER_SLASHINGS_VECTOR] = Gwei(0)
 func ProcessSlashingsReset(state state.BeaconState) (state.BeaconState, error) {
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	nextEpoch := currentEpoch + 1
 
 	// Set total slashed balances.
@@ -338,7 +342,7 @@ func ProcessSlashingsReset(state state.BeaconState) (state.BeaconState, error) {
 //    # Set randao mix
 //    state.randao_mixes[next_epoch % EPOCHS_PER_HISTORICAL_VECTOR] = get_randao_mix(state, current_epoch)
 func ProcessRandaoMixesReset(state state.BeaconState) (state.BeaconState, error) {
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	nextEpoch := currentEpoch + 1
 
 	// Set RANDAO mix.
@@ -371,7 +375,7 @@ func ProcessRandaoMixesReset(state state.BeaconState) (state.BeaconState, error)
 //        historical_batch = HistoricalBatch(block_roots=state.block_roots, state_roots=state.state_roots)
 //        state.historical_roots.append(hash_tree_root(historical_batch))
 func ProcessHistoricalRootsUpdate(state state.BeaconState) (state.BeaconState, error) {
-	currentEpoch := core.CurrentEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	nextEpoch := currentEpoch + 1
 
 	// Set historical root accumulator.
@@ -460,12 +464,12 @@ func ProcessFinalUpdates(state state.BeaconState) (state.BeaconState, error) {
 //    for a in attestations:
 //        output = output.union(get_attesting_indices(state, a.data, a.aggregation_bits))
 //    return set(filter(lambda index: not state.validators[index].slashed, output))
-func UnslashedAttestingIndices(state state.ReadOnlyBeaconState, atts []*ethpb.PendingAttestation) ([]types.ValidatorIndex, error) {
+func UnslashedAttestingIndices(ctx context.Context, state state.ReadOnlyBeaconState, atts []*ethpb.PendingAttestation) ([]types.ValidatorIndex, error) {
 	var setIndices []types.ValidatorIndex
 	seen := make(map[uint64]bool)
 
 	for _, att := range atts {
-		committee, err := helpers.BeaconCommitteeFromState(state, att.Data.Slot, att.Data.CommitteeIndex)
+		committee, err := helpers.BeaconCommitteeFromState(ctx, state, att.Data.Slot, att.Data.CommitteeIndex)
 		if err != nil {
 			return nil, err
 		}

beacon-chain/core/epoch/epoch_processing_test.go

@@ -1,14 +1,16 @@
 package epoch_test
 
 import (
+	"context"
 	"fmt"
+	"math"
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -46,7 +48,7 @@ func TestUnslashedAttestingIndices_CanSortAndFilter(t *testing.T) {
 	beaconState, err := v1.InitializeFromProto(base)
 	require.NoError(t, err)
 
-	indices, err := epoch.UnslashedAttestingIndices(beaconState, atts)
+	indices, err := epoch.UnslashedAttestingIndices(context.Background(), beaconState, atts)
 	require.NoError(t, err)
 	for i := 0; i < len(indices)-1; i++ {
 		if indices[i] >= indices[i+1] {
@@ -59,7 +61,7 @@ func TestUnslashedAttestingIndices_CanSortAndFilter(t *testing.T) {
 	validators = beaconState.Validators()
 	validators[slashedValidator].Slashed = true
 	require.NoError(t, beaconState.SetValidators(validators))
-	indices, err = epoch.UnslashedAttestingIndices(beaconState, atts)
+	indices, err = epoch.UnslashedAttestingIndices(context.Background(), beaconState, atts)
 	require.NoError(t, err)
 	for i := 0; i < len(indices); i++ {
 		assert.NotEqual(t, slashedValidator, indices[i], "Slashed validator %d is not filtered", slashedValidator)
@@ -92,7 +94,7 @@ func TestUnslashedAttestingIndices_DuplicatedAttestations(t *testing.T) {
 	beaconState, err := v1.InitializeFromProto(base)
 	require.NoError(t, err)
 
-	indices, err := epoch.UnslashedAttestingIndices(beaconState, atts)
+	indices, err := epoch.UnslashedAttestingIndices(context.Background(), beaconState, atts)
 	require.NoError(t, err)
 
 	for i := 0; i < len(indices)-1; i++ {
@@ -138,7 +140,7 @@ func TestAttestingBalance_CorrectBalance(t *testing.T) {
 	beaconState, err := v1.InitializeFromProto(base)
 	require.NoError(t, err)
 
-	balance, err := epoch.AttestingBalance(beaconState, atts)
+	balance, err := epoch.AttestingBalance(context.Background(), beaconState, atts)
 	require.NoError(t, err)
 	wanted := 256 * params.BeaconConfig().MaxEffectiveBalance
 	assert.Equal(t, wanted, balance)
@@ -241,7 +243,7 @@ func TestProcessSlashings_SlashedLess(t *testing.T) {
 
 func TestProcessFinalUpdates_CanProcess(t *testing.T) {
 	s := buildState(t, params.BeaconConfig().SlotsPerHistoricalRoot-1, uint64(params.BeaconConfig().SlotsPerEpoch))
-	ce := core.CurrentEpoch(s)
+	ce := time.CurrentEpoch(s)
 	ne := ce + 1
 	require.NoError(t, s.SetEth1DataVotes([]*ethpb.Eth1Data{}))
 	balances := s.Balances()
@@ -292,7 +294,7 @@ func TestProcessRegistryUpdates_NoRotation(t *testing.T) {
 	}
 	beaconState, err := v1.InitializeFromProto(base)
 	require.NoError(t, err)
-	newState, err := epoch.ProcessRegistryUpdates(beaconState)
+	newState, err := epoch.ProcessRegistryUpdates(context.Background(), beaconState)
 	require.NoError(t, err)
 	for i, validator := range newState.Validators() {
 		assert.Equal(t, params.BeaconConfig().MaxSeedLookahead, validator.ExitEpoch, "Could not update registry %d", i)
@@ -315,8 +317,8 @@ func TestProcessRegistryUpdates_EligibleToActivate(t *testing.T) {
 	}
 	beaconState, err := v1.InitializeFromProto(base)
 	require.NoError(t, err)
-	currentEpoch := core.CurrentEpoch(beaconState)
-	newState, err := epoch.ProcessRegistryUpdates(beaconState)
+	currentEpoch := time.CurrentEpoch(beaconState)
+	newState, err := epoch.ProcessRegistryUpdates(context.Background(), beaconState)
 	require.NoError(t, err)
 	for i, validator := range newState.Validators() {
 		assert.Equal(t, currentEpoch+1, validator.ActivationEligibilityEpoch, "Could not update registry %d, unexpected activation eligibility epoch", i)
@@ -344,7 +346,7 @@ func TestProcessRegistryUpdates_ActivationCompletes(t *testing.T) {
 	}
 	beaconState, err := v1.InitializeFromProto(base)
 	require.NoError(t, err)
-	newState, err := epoch.ProcessRegistryUpdates(beaconState)
+	newState, err := epoch.ProcessRegistryUpdates(context.Background(), beaconState)
 	require.NoError(t, err)
 	for i, validator := range newState.Validators() {
 		assert.Equal(t, params.BeaconConfig().MaxSeedLookahead, validator.ExitEpoch, "Could not update registry %d, unexpected exit slot", i)
@@ -368,7 +370,7 @@ func TestProcessRegistryUpdates_ValidatorsEjected(t *testing.T) {
 	}
 	beaconState, err := v1.InitializeFromProto(base)
 	require.NoError(t, err)
-	newState, err := epoch.ProcessRegistryUpdates(beaconState)
+	newState, err := epoch.ProcessRegistryUpdates(context.Background(), beaconState)
 	require.NoError(t, err)
 	for i, validator := range newState.Validators() {
 		assert.Equal(t, params.BeaconConfig().MaxSeedLookahead+1, validator.ExitEpoch, "Could not update registry %d, unexpected exit slot", i)
@@ -393,7 +395,7 @@ func TestProcessRegistryUpdates_CanExits(t *testing.T) {
 	}
 	beaconState, err := v1.InitializeFromProto(base)
 	require.NoError(t, err)
-	newState, err := epoch.ProcessRegistryUpdates(beaconState)
+	newState, err := epoch.ProcessRegistryUpdates(context.Background(), beaconState)
 	require.NoError(t, err)
 	for i, validator := range newState.Validators() {
 		assert.Equal(t, exitEpoch, validator.ExitEpoch, "Could not update registry %d, unexpected exit slot", i)
@@ -439,3 +441,16 @@ func buildState(t testing.TB, slot types.Slot, validatorCount uint64) state.Beac
 	}
 	return s
 }
+
+func TestProcessSlashings_BadValue(t *testing.T) {
+	base := &ethpb.BeaconState{
+		Slot:       0,
+		Validators: []*ethpb.Validator{{Slashed: true}},
+		Balances:   []uint64{params.BeaconConfig().MaxEffectiveBalance},
+		Slashings:  []uint64{math.MaxUint64, 1e9},
+	}
+	s, err := v1.InitializeFromProto(base)
+	require.NoError(t, err)
+	_, err = epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplier)
+	require.ErrorContains(t, "addition overflows", err)
+}

beacon-chain/core/epoch/precompute/BUILD.bazel

@@ -16,14 +16,15 @@ go_library(
         "//testing/spectest:__subpackages__",
     ],
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/params:go_default_library",
         "//math:go_default_library",
         "//monitoring/tracing:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/attestation:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
         "@io_opencensus_go//trace:go_default_library",
@@ -41,9 +42,9 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/epoch:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/v1:go_default_library",
         "//config/params:go_default_library",

beacon-chain/core/epoch/precompute/attestation.go

@@ -6,8 +6,8 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/monitoring/tracing"
@@ -53,7 +53,7 @@ func ProcessAttestations(
 			return nil, nil, errors.Wrap(err, "could not check validator attested previous epoch")
 		}
 
-		committee, err := helpers.BeaconCommitteeFromState(state, a.Data.Slot, a.Data.CommitteeIndex)
+		committee, err := helpers.BeaconCommitteeFromState(ctx, state, a.Data.Slot, a.Data.CommitteeIndex)
 		if err != nil {
 			return nil, nil, err
 		}
@@ -71,7 +71,7 @@ func ProcessAttestations(
 
 // AttestedCurrentEpoch returns true if attestation `a` attested once in current epoch and/or epoch boundary block.
 func AttestedCurrentEpoch(s state.ReadOnlyBeaconState, a *ethpb.PendingAttestation) (bool, bool, error) {
-	currentEpoch := core.CurrentEpoch(s)
+	currentEpoch := time.CurrentEpoch(s)
 	var votedCurrentEpoch, votedTarget bool
 	// Did validator vote current epoch.
 	if a.Data.Target.Epoch == currentEpoch {
@@ -89,7 +89,7 @@ func AttestedCurrentEpoch(s state.ReadOnlyBeaconState, a *ethpb.PendingAttestati
 
 // AttestedPrevEpoch returns true if attestation `a` attested once in previous epoch and epoch boundary block and/or the same head.
 func AttestedPrevEpoch(s state.ReadOnlyBeaconState, a *ethpb.PendingAttestation) (bool, bool, bool, error) {
-	prevEpoch := core.PrevEpoch(s)
+	prevEpoch := time.PrevEpoch(s)
 	var votedPrevEpoch, votedTarget, votedHead bool
 	// Did validator vote previous epoch.
 	if a.Data.Target.Epoch == prevEpoch {

beacon-chain/core/epoch/precompute/attestation_test.go

@@ -181,7 +181,7 @@ func TestProcessAttestations(t *testing.T) {
 	pVals, _, err = precompute.ProcessAttestations(context.Background(), beaconState, pVals, &precompute.Balance{})
 	require.NoError(t, err)
 
-	committee, err := helpers.BeaconCommitteeFromState(beaconState, att1.Data.Slot, att1.Data.CommitteeIndex)
+	committee, err := helpers.BeaconCommitteeFromState(context.Background(), beaconState, att1.Data.Slot, att1.Data.CommitteeIndex)
 	require.NoError(t, err)
 	indices, err := attestation.AttestingIndices(att1.AggregationBits, committee)
 	require.NoError(t, err)
@@ -190,7 +190,7 @@ func TestProcessAttestations(t *testing.T) {
 			t.Error("Not a prev epoch attester")
 		}
 	}
-	committee, err = helpers.BeaconCommitteeFromState(beaconState, att2.Data.Slot, att2.Data.CommitteeIndex)
+	committee, err = helpers.BeaconCommitteeFromState(context.Background(), beaconState, att2.Data.Slot, att2.Data.CommitteeIndex)
 	require.NoError(t, err)
 	indices, err = attestation.AttestingIndices(att2.AggregationBits, committee)
 	require.NoError(t, err)

beacon-chain/core/epoch/precompute/justification_finalization.go

@@ -2,10 +2,11 @@ package precompute
 
 import (
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // ProcessJustificationAndFinalizationPreCompute processes justification and finalization during
@@ -25,7 +26,7 @@ import (
 //    current_target_balance = get_attesting_balance(state, current_attestations)
 //    weigh_justification_and_finalization(state, total_active_balance, previous_target_balance, current_target_balance)
 func ProcessJustificationAndFinalizationPreCompute(state state.BeaconState, pBal *Balance) (state.BeaconState, error) {
-	canProcessSlot, err := core.StartSlot(2 /*epoch*/)
+	canProcessSlot, err := slots.EpochStart(2 /*epoch*/)
 	if err != nil {
 		return nil, err
 	}
@@ -78,8 +79,8 @@ func ProcessJustificationAndFinalizationPreCompute(state state.BeaconState, pBal
 //        state.finalized_checkpoint = old_current_justified_checkpoint
 func weighJustificationAndFinalization(state state.BeaconState,
 	totalActiveBalance, prevEpochTargetBalance, currEpochTargetBalance uint64) (state.BeaconState, error) {
-	prevEpoch := core.PrevEpoch(state)
-	currentEpoch := core.CurrentEpoch(state)
+	prevEpoch := time.PrevEpoch(state)
+	currentEpoch := time.CurrentEpoch(state)
 	oldPrevJustifiedCheckpoint := state.PreviousJustifiedCheckpoint()
 	oldCurrJustifiedCheckpoint := state.CurrentJustifiedCheckpoint()
 

beacon-chain/core/epoch/precompute/new.go

@@ -7,8 +7,8 @@ import (
 	"context"
 
 	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"go.opencensus.io/trace"
@@ -24,8 +24,8 @@ func New(ctx context.Context, s state.BeaconState) ([]*Validator, *Balance, erro
 	pValidators := make([]*Validator, s.NumValidators())
 	pBal := &Balance{}
 
-	currentEpoch := core.CurrentEpoch(s)
-	prevEpoch := core.PrevEpoch(s)
+	currentEpoch := time.CurrentEpoch(s)
+	prevEpoch := time.PrevEpoch(s)
 
 	if err := s.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
 		// Was validator withdrawable or slashed

beacon-chain/core/epoch/precompute/reward_penalty.go

@@ -3,8 +3,8 @@ package precompute
 import (
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/math"
@@ -23,7 +23,7 @@ func ProcessRewardsAndPenaltiesPrecompute(
 	proRewardsFunc proposerRewardsFunc,
 ) (state.BeaconState, error) {
 	// Can't process rewards and penalties in genesis epoch.
-	if core.CurrentEpoch(state) == 0 {
+	if time.CurrentEpoch(state) == 0 {
 		return state, nil
 	}
 
@@ -47,7 +47,10 @@ func ProcessRewardsAndPenaltiesPrecompute(
 
 		// Compute the post balance of the validator after accounting for the
 		// attester and proposer rewards and penalties.
-		validatorBals[i] = helpers.IncreaseBalanceWithVal(validatorBals[i], attsRewards[i]+proposerRewards[i])
+		validatorBals[i], err = helpers.IncreaseBalanceWithVal(validatorBals[i], attsRewards[i]+proposerRewards[i])
+		if err != nil {
+			return nil, err
+		}
 		validatorBals[i] = helpers.DecreaseBalanceWithVal(validatorBals[i], attsPenalties[i])
 
 		vp[i].AfterEpochTransitionBalance = validatorBals[i]
@@ -66,7 +69,7 @@ func AttestationsDelta(state state.ReadOnlyBeaconState, pBal *Balance, vp []*Val
 	numOfVals := state.NumValidators()
 	rewards := make([]uint64, numOfVals)
 	penalties := make([]uint64, numOfVals)
-	prevEpoch := core.PrevEpoch(state)
+	prevEpoch := time.PrevEpoch(state)
 	finalizedEpoch := state.FinalizedCheckpointEpoch()
 
 	sqrtActiveCurrentEpoch := math.IntegerSquareRoot(pBal.ActiveCurrentEpoch)

beacon-chain/core/epoch/precompute/reward_penalty_test.go

@@ -7,9 +7,9 @@ import (
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -100,7 +100,7 @@ func TestAttestationDeltaPrecompute(t *testing.T) {
 	bp.PrevEpochHeadAttested = bp.PrevEpochHeadAttested * 2 / 3
 	rewards, penalties, err := AttestationsDelta(beaconState, bp, vp)
 	require.NoError(t, err)
-	attestedBalance, err := epoch.AttestingBalance(beaconState, atts)
+	attestedBalance, err := epoch.AttestingBalance(context.Background(), beaconState, atts)
 	require.NoError(t, err)
 	totalBalance, err := helpers.TotalActiveBalance(beaconState)
 	require.NoError(t, err)
@@ -246,7 +246,7 @@ func TestProcessRewardsAndPenaltiesPrecompute_SlashedInactivePenalty(t *testing.
 	rewards, penalties, err := AttestationsDelta(beaconState, bp, vp)
 	require.NoError(t, err)
 
-	finalityDelay := core.PrevEpoch(beaconState) - beaconState.FinalizedCheckpointEpoch()
+	finalityDelay := time.PrevEpoch(beaconState) - beaconState.FinalizedCheckpointEpoch()
 	for _, i := range slashedAttestedIndices {
 		base, err := baseReward(beaconState, i)
 		require.NoError(t, err, "Could not get base reward")

beacon-chain/core/epoch/precompute/slashing.go

@@ -2,8 +2,8 @@ package precompute
 
 import (
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/math"
@@ -13,7 +13,7 @@ import (
 // ProcessSlashingsPrecompute processes the slashed validators during epoch processing.
 // This is an optimized version by passing in precomputed total epoch balances.
 func ProcessSlashingsPrecompute(s state.BeaconState, pBal *Balance) error {
-	currentEpoch := core.CurrentEpoch(s)
+	currentEpoch := time.CurrentEpoch(s)
 	exitLength := params.BeaconConfig().EpochsPerSlashingsVector
 
 	// Compute the sum of state slashings

beacon-chain/core/feed/BUILD.bazel

@@ -6,6 +6,6 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/core/feed",
     visibility = [
         "//beacon-chain:__subpackages__",
-        "//shared:__subpackages__",
+        "//testing/slasher/simulator:__subpackages__",
     ],
 )

beacon-chain/core/feed/state/BUILD.bazel

@@ -7,7 +7,10 @@ go_library(
         "notifier.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state",
-    visibility = ["//beacon-chain:__subpackages__"],
+    visibility = [
+        "//beacon-chain:__subpackages__",
+        "//testing/slasher/simulator:__subpackages__",
+    ],
     deps = [
         "//async/event:go_default_library",
         "//proto/prysm/v1alpha1/block:go_default_library",

beacon-chain/core/helpers/BUILD.bazel

@@ -10,7 +10,6 @@ go_library(
         "randao.go",
         "rewards_penalties.go",
         "shuffle.go",
-        "signing_root.go",
         "sync_committee.go",
         "validators.go",
         "weak_subjectivity.go",
@@ -19,17 +18,18 @@ go_library(
     visibility = [
         "//beacon-chain:__subpackages__",
         "//contracts/deposit:__pkg__",
+        "//crypto/keystore:__pkg__",
         "//fuzz:__pkg__",
         "//network/forks:__pkg__",
+        "//proto/prysm/v1alpha1:__subpackages__",
         "//proto/prysm/v1alpha1/attestation:__pkg__",
         "//runtime/interop:__pkg__",
-        "//shared/attestationutil:__pkg__",
-        "//shared/keystore:__pkg__",
         "//slasher:__subpackages__",
         "//testing/altair:__pkg__",
         "//testing/benchmark/benchmark_files:__subpackages__",
         "//testing/endtoend/evaluators:__pkg__",
         "//testing/fuzz:__pkg__",
+        "//testing/slasher/simulator:__pkg__",
         "//testing/spectest:__subpackages__",
         "//testing/util:__pkg__",
         "//tools:__subpackages__",
@@ -37,7 +37,7 @@ go_library(
     ],
     deps = [
         "//beacon-chain/cache:go_default_library",
-        "//beacon-chain/core:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/params:go_default_library",
         "//container/slice:go_default_library",
@@ -49,8 +49,10 @@ go_library(
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/block:go_default_library",
         "//time:go_default_library",
-        "@com_github_ferranbt_fastssz//:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
@@ -67,7 +69,6 @@ go_test(
         "randao_test.go",
         "rewards_penalties_test.go",
         "shuffle_test.go",
-        "signing_root_test.go",
         "sync_committee_test.go",
         "validators_test.go",
         "weak_subjectivity_test.go",
@@ -76,7 +77,7 @@ go_test(
     shard_count = 2,
     deps = [
         "//beacon-chain/cache:go_default_library",
-        "//beacon-chain/core:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/v1:go_default_library",
         "//beacon-chain/state/v2:go_default_library",
@@ -91,7 +92,7 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time:go_default_library",
-        "@com_github_google_gofuzz//:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
     ],

beacon-chain/core/helpers/attestation.go

@@ -7,12 +7,12 @@ import (
 	"time"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
 	"github.com/prysmaticlabs/prysm/crypto/hash"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	prysmTime "github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // ValidateNilAttestation checks if any composite field of input attestation is nil.
@@ -40,7 +40,7 @@ func ValidateNilAttestation(attestation *ethpb.Attestation) error {
 // ValidateSlotTargetEpoch checks if attestation data's epoch matches target checkpoint's epoch.
 // It is recommended to run `ValidateNilAttestation` first to ensure `data.Target` can't be nil.
 func ValidateSlotTargetEpoch(data *ethpb.AttestationData) error {
-	if core.SlotToEpoch(data.Slot) != data.Target.Epoch {
+	if slots.ToEpoch(data.Slot) != data.Target.Epoch {
 		return fmt.Errorf("slot %d does not match target epoch %d", data.Slot, data.Target.Epoch)
 	}
 	return nil
@@ -121,7 +121,7 @@ func ComputeSubnetForAttestation(activeValCount uint64, att *ethpb.Attestation)
 //
 //    return uint64((committees_since_epoch_start + committee_index) % ATTESTATION_SUBNET_COUNT)
 func ComputeSubnetFromCommitteeAndSlot(activeValCount uint64, comIdx types.CommitteeIndex, attSlot types.Slot) uint64 {
-	slotSinceStart := core.SlotsSinceEpochStarts(attSlot)
+	slotSinceStart := slots.SinceEpochStarts(attSlot)
 	comCount := SlotCommitteeCount(activeValCount)
 	commsSinceStart := uint64(slotSinceStart.Mul(comCount))
 	computedSubnet := (commsSinceStart + uint64(comIdx)) % params.BeaconNetworkConfig().AttestationSubnetCount
@@ -142,14 +142,14 @@ func ComputeSubnetFromCommitteeAndSlot(activeValCount uint64, comIdx types.Commi
 //   valid_attestation_slot = 101
 // In the attestation must be within the range of 95 to 102 in the example above.
 func ValidateAttestationTime(attSlot types.Slot, genesisTime time.Time, clockDisparity time.Duration) error {
-	if err := core.ValidateSlotClock(attSlot, uint64(genesisTime.Unix())); err != nil {
+	if err := slots.ValidateClock(attSlot, uint64(genesisTime.Unix())); err != nil {
 		return err
 	}
-	attTime, err := core.SlotToTime(uint64(genesisTime.Unix()), attSlot)
+	attTime, err := slots.ToTime(uint64(genesisTime.Unix()), attSlot)
 	if err != nil {
 		return err
 	}
-	currentSlot := core.SlotsSince(genesisTime)
+	currentSlot := slots.Since(genesisTime)
 
 	// When receiving an attestation, it can be from the future.
 	// so the upper bounds is set to now + clockDisparity(SECONDS_PER_SLOT * 2).
@@ -163,7 +163,7 @@ func ValidateAttestationTime(attSlot types.Slot, genesisTime time.Time, clockDis
 	if currentSlot > params.BeaconNetworkConfig().AttestationPropagationSlotRange {
 		lowerBoundsSlot = currentSlot - params.BeaconNetworkConfig().AttestationPropagationSlotRange
 	}
-	lowerTime, err := core.SlotToTime(uint64(genesisTime.Unix()), lowerBoundsSlot)
+	lowerTime, err := slots.ToTime(uint64(genesisTime.Unix()), lowerBoundsSlot)
 	if err != nil {
 		return err
 	}
@@ -187,7 +187,7 @@ func VerifyCheckpointEpoch(c *ethpb.Checkpoint, genesis time.Time) bool {
 	now := uint64(prysmTime.Now().Unix())
 	genesisTime := uint64(genesis.Unix())
 	currentSlot := types.Slot((now - genesisTime) / params.BeaconConfig().SecondsPerSlot)
-	currentEpoch := core.SlotToEpoch(currentSlot)
+	currentEpoch := slots.ToEpoch(currentSlot)
 
 	var prevEpoch types.Epoch
 	if currentEpoch > 1 {

beacon-chain/core/helpers/attestation_test.go

@@ -1,12 +1,12 @@
 package helpers_test
 
 import (
+	"context"
 	"strconv"
 	"testing"
 	"time"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -17,12 +17,13 @@ import (
 	"github.com/prysmaticlabs/prysm/testing/require"
 	"github.com/prysmaticlabs/prysm/testing/util"
 	prysmTime "github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 func TestAttestation_IsAggregator(t *testing.T) {
 	t.Run("aggregator", func(t *testing.T) {
 		beaconState, privKeys := util.DeterministicGenesisState(t, 100)
-		committee, err := helpers.BeaconCommitteeFromState(beaconState, 0, 0)
+		committee, err := helpers.BeaconCommitteeFromState(context.Background(), beaconState, 0, 0)
 		require.NoError(t, err)
 		sig := privKeys[0].Sign([]byte{'A'})
 		agg, err := helpers.IsAggregator(uint64(len(committee)), sig.Marshal())
@@ -35,7 +36,7 @@ func TestAttestation_IsAggregator(t *testing.T) {
 		defer params.UseMainnetConfig()
 		beaconState, privKeys := util.DeterministicGenesisState(t, 2048)
 
-		committee, err := helpers.BeaconCommitteeFromState(beaconState, 0, 0)
+		committee, err := helpers.BeaconCommitteeFromState(context.Background(), beaconState, 0, 0)
 		require.NoError(t, err)
 		sig := privKeys[0].Sign([]byte{'A'})
 		agg, err := helpers.IsAggregator(uint64(len(committee)), sig.Marshal())
@@ -117,7 +118,7 @@ func TestAttestation_ComputeSubnetForAttestation(t *testing.T) {
 		},
 		Signature: []byte{'B'},
 	}
-	valCount, err := helpers.ActiveValidatorCount(state, core.SlotToEpoch(att.Data.Slot))
+	valCount, err := helpers.ActiveValidatorCount(context.Background(), state, slots.ToEpoch(att.Data.Slot))
 	require.NoError(t, err)
 	sub := helpers.ComputeSubnetForAttestation(valCount, att)
 	assert.Equal(t, uint64(6), sub, "Did not get correct subnet for attestation")

beacon-chain/core/helpers/beacon_committee.go

@@ -4,6 +4,7 @@ package helpers
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"sort"
 
@@ -11,7 +12,7 @@ import (
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/container/slice"
@@ -19,6 +20,7 @@ import (
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/math"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 var (
@@ -71,14 +73,14 @@ func SlotCommitteeCount(activeValidatorCount uint64) uint64 {
 //        index=(slot % SLOTS_PER_EPOCH) * committees_per_slot + index,
 //        count=committees_per_slot * SLOTS_PER_EPOCH,
 //    )
-func BeaconCommitteeFromState(state state.ReadOnlyBeaconState, slot types.Slot, committeeIndex types.CommitteeIndex) ([]types.ValidatorIndex, error) {
-	epoch := core.SlotToEpoch(slot)
+func BeaconCommitteeFromState(ctx context.Context, state state.ReadOnlyBeaconState, slot types.Slot, committeeIndex types.CommitteeIndex) ([]types.ValidatorIndex, error) {
+	epoch := slots.ToEpoch(slot)
 	seed, err := Seed(state, epoch, params.BeaconConfig().DomainBeaconAttester)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get seed")
 	}
 
-	committee, err := committeeCache.Committee(slot, seed, committeeIndex)
+	committee, err := committeeCache.Committee(ctx, slot, seed, committeeIndex)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not interface with committee cache")
 	}
@@ -86,12 +88,12 @@ func BeaconCommitteeFromState(state state.ReadOnlyBeaconState, slot types.Slot,
 		return committee, nil
 	}
 
-	activeIndices, err := ActiveValidatorIndices(state, epoch)
+	activeIndices, err := ActiveValidatorIndices(ctx, state, epoch)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get active indices")
 	}
 
-	return BeaconCommittee(activeIndices, seed, slot, committeeIndex)
+	return BeaconCommittee(ctx, activeIndices, seed, slot, committeeIndex)
 }
 
 // BeaconCommittee returns the beacon committee of a given slot and committee index. The
@@ -112,12 +114,13 @@ func BeaconCommitteeFromState(state state.ReadOnlyBeaconState, slot types.Slot,
 //        count=committees_per_slot * SLOTS_PER_EPOCH,
 //    )
 func BeaconCommittee(
+	ctx context.Context,
 	validatorIndices []types.ValidatorIndex,
 	seed [32]byte,
 	slot types.Slot,
 	committeeIndex types.CommitteeIndex,
 ) ([]types.ValidatorIndex, error) {
-	committee, err := committeeCache.Committee(slot, seed, committeeIndex)
+	committee, err := committeeCache.Committee(ctx, slot, seed, committeeIndex)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not interface with committee cache")
 	}
@@ -151,10 +154,11 @@ type CommitteeAssignmentContainer struct {
 // 3. Determine the attesting slot for each committee.
 // 4. Construct a map of validator indices pointing to the respective committees.
 func CommitteeAssignments(
+	ctx context.Context,
 	state state.BeaconState,
 	epoch types.Epoch,
 ) (map[types.ValidatorIndex]*CommitteeAssignmentContainer, map[types.ValidatorIndex][]types.Slot, error) {
-	nextEpoch := core.NextEpoch(state)
+	nextEpoch := time.NextEpoch(state)
 	if epoch > nextEpoch {
 		return nil, nil, fmt.Errorf(
 			"epoch %d can't be greater than next epoch %d",
@@ -166,7 +170,7 @@ func CommitteeAssignments(
 	// We determine the slots in which proposers are supposed to act.
 	// Some validators may need to propose multiple times per epoch, so
 	// we use a map of proposer idx -> []slot to keep track of this possibility.
-	startSlot, err := core.StartSlot(epoch)
+	startSlot, err := slots.EpochStart(epoch)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -181,14 +185,14 @@ func CommitteeAssignments(
 		if err := state.SetSlot(slot); err != nil {
 			return nil, nil, err
 		}
-		i, err := BeaconProposerIndex(state)
+		i, err := BeaconProposerIndex(ctx, state)
 		if err != nil {
 			return nil, nil, errors.Wrapf(err, "could not check proposer at slot %d", state.Slot())
 		}
 		proposerIndexToSlots[i] = append(proposerIndexToSlots[i], slot)
 	}
 
-	activeValidatorIndices, err := ActiveValidatorIndices(state, epoch)
+	activeValidatorIndices, err := ActiveValidatorIndices(ctx, state, epoch)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -202,7 +206,7 @@ func CommitteeAssignments(
 		// Compute committees.
 		for j := uint64(0); j < numCommitteesPerSlot; j++ {
 			slot := startSlot + i
-			committee, err := BeaconCommitteeFromState(state, slot, types.CommitteeIndex(j) /*committee index*/)
+			committee, err := BeaconCommitteeFromState(ctx, state, slot, types.CommitteeIndex(j) /*committee index*/)
 			if err != nil {
 				return nil, nil, err
 			}
@@ -234,8 +238,8 @@ func VerifyBitfieldLength(bf bitfield.Bitfield, committeeSize uint64) error {
 
 // VerifyAttestationBitfieldLengths verifies that an attestations aggregation bitfields is
 // a valid length matching the size of the committee.
-func VerifyAttestationBitfieldLengths(state state.ReadOnlyBeaconState, att *ethpb.Attestation) error {
-	committee, err := BeaconCommitteeFromState(state, att.Data.Slot, att.Data.CommitteeIndex)
+func VerifyAttestationBitfieldLengths(ctx context.Context, state state.ReadOnlyBeaconState, att *ethpb.Attestation) error {
+	committee, err := BeaconCommitteeFromState(ctx, state, att.Data.Slot, att.Data.CommitteeIndex)
 	if err != nil {
 		return errors.Wrap(err, "could not retrieve beacon committees")
 	}
@@ -280,7 +284,6 @@ func UpdateCommitteeCache(state state.ReadOnlyBeaconState, epoch types.Epoch) er
 		if err != nil {
 			return err
 		}
-
 		if committeeCache.HasEntry(string(seed[:])) {
 			return nil
 		}
@@ -315,19 +318,16 @@ func UpdateCommitteeCache(state state.ReadOnlyBeaconState, epoch types.Epoch) er
 }
 
 // UpdateProposerIndicesInCache updates proposer indices entry of the committee cache.
-func UpdateProposerIndicesInCache(state state.ReadOnlyBeaconState) error {
-	// The cache uses the state root at the (current epoch - 2)'s slot as key. (e.g. for epoch 2, the key is root at slot 31)
+func UpdateProposerIndicesInCache(ctx context.Context, state state.ReadOnlyBeaconState) error {
+	// The cache uses the state root at the (current epoch - 1)'s slot as key. (e.g. for epoch 2, the key is root at slot 63)
 	// Which is the reason why we skip genesis epoch.
-	if core.CurrentEpoch(state) <= params.BeaconConfig().GenesisEpoch+params.BeaconConfig().MinSeedLookahead {
+	if time.CurrentEpoch(state) <= params.BeaconConfig().GenesisEpoch+params.BeaconConfig().MinSeedLookahead {
 		return nil
 	}
 
-	// Use state root from (current_epoch - 1 - lookahead))
-	wantedEpoch := core.CurrentEpoch(state) - 1
-	if wantedEpoch >= params.BeaconConfig().MinSeedLookahead {
-		wantedEpoch -= params.BeaconConfig().MinSeedLookahead
-	}
-	s, err := core.EndSlot(wantedEpoch)
+	// Use state root from (current_epoch - 1))
+	wantedEpoch := time.PrevEpoch(state)
+	s, err := slots.EpochEnd(wantedEpoch)
 	if err != nil {
 		return err
 	}
@@ -348,7 +348,7 @@ func UpdateProposerIndicesInCache(state state.ReadOnlyBeaconState) error {
 		return nil
 	}
 
-	indices, err := ActiveValidatorIndices(state, core.CurrentEpoch(state))
+	indices, err := ActiveValidatorIndices(ctx, state, time.CurrentEpoch(state))
 	if err != nil {
 		return err
 	}
@@ -416,12 +416,12 @@ func precomputeProposerIndices(state state.ReadOnlyBeaconState, activeIndices []
 	hashFunc := hash.CustomSHA256Hasher()
 	proposerIndices := make([]types.ValidatorIndex, params.BeaconConfig().SlotsPerEpoch)
 
-	e := core.CurrentEpoch(state)
+	e := time.CurrentEpoch(state)
 	seed, err := Seed(state, e, params.BeaconConfig().DomainBeaconProposer)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not generate seed")
 	}
-	slot, err := core.StartSlot(e)
+	slot, err := slots.EpochStart(e)
 	if err != nil {
 		return nil, err
 	}

beacon-chain/core/helpers/beacon_committee_test.go

@@ -1,13 +1,14 @@
 package helpers
 
 import (
+	"context"
 	"fmt"
 	"strconv"
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/container/slice"
@@ -16,6 +17,7 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 func TestComputeCommittee_WithoutCache(t *testing.T) {
@@ -43,8 +45,8 @@ func TestComputeCommittee_WithoutCache(t *testing.T) {
 	})
 	require.NoError(t, err)
 
-	epoch := core.CurrentEpoch(state)
-	indices, err := ActiveValidatorIndices(state, epoch)
+	epoch := time.CurrentEpoch(state)
+	indices, err := ActiveValidatorIndices(context.Background(), state, epoch)
 	require.NoError(t, err)
 	seed, err := Seed(state, epoch, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(t, err)
@@ -94,7 +96,7 @@ func TestCommitteeAssignments_CannotRetrieveFutureEpoch(t *testing.T) {
 		Slot: 0, // Epoch 0.
 	})
 	require.NoError(t, err)
-	_, _, err = CommitteeAssignments(state, epoch+1)
+	_, _, err = CommitteeAssignments(context.Background(), state, epoch+1)
 	assert.ErrorContains(t, "can't be greater than next epoch", err)
 }
 
@@ -117,7 +119,7 @@ func TestCommitteeAssignments_NoProposerForSlot0(t *testing.T) {
 	})
 	require.NoError(t, err)
 	ClearCache()
-	_, proposerIndexToSlots, err := CommitteeAssignments(state, 0)
+	_, proposerIndexToSlots, err := CommitteeAssignments(context.Background(), state, 0)
 	require.NoError(t, err, "Failed to determine CommitteeAssignments")
 	for _, slots := range proposerIndexToSlots {
 		for _, s := range slots {
@@ -189,7 +191,7 @@ func TestCommitteeAssignments_CanRetrieve(t *testing.T) {
 	for i, tt := range tests {
 		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
 			ClearCache()
-			validatorIndexToCommittee, proposerIndexToSlots, err := CommitteeAssignments(state, core.SlotToEpoch(tt.slot))
+			validatorIndexToCommittee, proposerIndexToSlots, err := CommitteeAssignments(context.Background(), state, slots.ToEpoch(tt.slot))
 			require.NoError(t, err, "Failed to determine CommitteeAssignments")
 			cac := validatorIndexToCommittee[tt.index]
 			assert.Equal(t, tt.committeeIndex, cac.CommitteeIndex, "Unexpected committeeIndex for validator index %d", tt.index)
@@ -224,11 +226,11 @@ func TestCommitteeAssignments_CannotRetrieveFuture(t *testing.T) {
 		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
 	})
 	require.NoError(t, err)
-	_, proposerIndxs, err := CommitteeAssignments(state, core.CurrentEpoch(state))
+	_, proposerIndxs, err := CommitteeAssignments(context.Background(), state, time.CurrentEpoch(state))
 	require.NoError(t, err)
 	require.NotEqual(t, 0, len(proposerIndxs), "wanted non-zero proposer index set")
 
-	_, proposerIndxs, err = CommitteeAssignments(state, core.CurrentEpoch(state)+1)
+	_, proposerIndxs, err = CommitteeAssignments(context.Background(), state, time.CurrentEpoch(state)+1)
 	require.NoError(t, err)
 	require.Equal(t, 0, len(proposerIndxs), "wanted empty proposer index set")
 }
@@ -250,7 +252,7 @@ func TestCommitteeAssignments_EverySlotHasMin1Proposer(t *testing.T) {
 	require.NoError(t, err)
 	ClearCache()
 	epoch := types.Epoch(1)
-	_, proposerIndexToSlots, err := CommitteeAssignments(state, epoch)
+	_, proposerIndexToSlots, err := CommitteeAssignments(context.Background(), state, epoch)
 	require.NoError(t, err, "Failed to determine CommitteeAssignments")
 
 	slotsWithProposers := make(map[types.Slot]bool)
@@ -260,9 +262,9 @@ func TestCommitteeAssignments_EverySlotHasMin1Proposer(t *testing.T) {
 		}
 	}
 	assert.Equal(t, uint64(params.BeaconConfig().SlotsPerEpoch), uint64(len(slotsWithProposers)), "Unexpected slots")
-	startSlot, err := core.StartSlot(epoch)
+	startSlot, err := slots.EpochStart(epoch)
 	require.NoError(t, err)
-	endSlot, err := core.StartSlot(epoch + 1)
+	endSlot, err := slots.EpochStart(epoch + 1)
 	require.NoError(t, err)
 	for i := startSlot; i < endSlot; i++ {
 		hasProposer := slotsWithProposers[i]
@@ -358,7 +360,7 @@ func TestVerifyAttestationBitfieldLengths_OK(t *testing.T) {
 	for i, tt := range tests {
 		ClearCache()
 		require.NoError(t, state.SetSlot(tt.stateSlot))
-		err := VerifyAttestationBitfieldLengths(state, tt.attestation)
+		err := VerifyAttestationBitfieldLengths(context.Background(), state, tt.attestation)
 		if tt.verificationFailure {
 			assert.NotNil(t, err, "Verification succeeded when it was supposed to fail")
 		} else {
@@ -384,14 +386,14 @@ func TestUpdateCommitteeCache_CanUpdate(t *testing.T) {
 		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
 	})
 	require.NoError(t, err)
-	require.NoError(t, UpdateCommitteeCache(state, core.CurrentEpoch(state)))
+	require.NoError(t, UpdateCommitteeCache(state, time.CurrentEpoch(state)))
 
 	epoch := types.Epoch(1)
 	idx := types.CommitteeIndex(1)
 	seed, err := Seed(state, epoch, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(t, err)
 
-	indices, err = committeeCache.Committee(params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epoch)), seed, idx)
+	indices, err = committeeCache.Committee(context.Background(), params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epoch)), seed, idx)
 	require.NoError(t, err)
 	assert.Equal(t, params.BeaconConfig().TargetCommitteeSize, uint64(len(indices)), "Did not save correct indices lengths")
 }
@@ -409,8 +411,8 @@ func BenchmarkComputeCommittee300000_WithPreCache(b *testing.B) {
 	})
 	require.NoError(b, err)
 
-	epoch := core.CurrentEpoch(state)
-	indices, err := ActiveValidatorIndices(state, epoch)
+	epoch := time.CurrentEpoch(state)
+	indices, err := ActiveValidatorIndices(context.Background(), state, epoch)
 	require.NoError(b, err)
 	seed, err := Seed(state, epoch, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(b, err)
@@ -443,8 +445,8 @@ func BenchmarkComputeCommittee3000000_WithPreCache(b *testing.B) {
 	})
 	require.NoError(b, err)
 
-	epoch := core.CurrentEpoch(state)
-	indices, err := ActiveValidatorIndices(state, epoch)
+	epoch := time.CurrentEpoch(state)
+	indices, err := ActiveValidatorIndices(context.Background(), state, epoch)
 	require.NoError(b, err)
 	seed, err := Seed(state, epoch, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(b, err)
@@ -477,8 +479,8 @@ func BenchmarkComputeCommittee128000_WithOutPreCache(b *testing.B) {
 	})
 	require.NoError(b, err)
 
-	epoch := core.CurrentEpoch(state)
-	indices, err := ActiveValidatorIndices(state, epoch)
+	epoch := time.CurrentEpoch(state)
+	indices, err := ActiveValidatorIndices(context.Background(), state, epoch)
 	require.NoError(b, err)
 	seed, err := Seed(state, epoch, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(b, err)
@@ -512,8 +514,8 @@ func BenchmarkComputeCommittee1000000_WithOutCache(b *testing.B) {
 	})
 	require.NoError(b, err)
 
-	epoch := core.CurrentEpoch(state)
-	indices, err := ActiveValidatorIndices(state, epoch)
+	epoch := time.CurrentEpoch(state)
+	indices, err := ActiveValidatorIndices(context.Background(), state, epoch)
 	require.NoError(b, err)
 	seed, err := Seed(state, epoch, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(b, err)
@@ -547,8 +549,8 @@ func BenchmarkComputeCommittee4000000_WithOutCache(b *testing.B) {
 	})
 	require.NoError(b, err)
 
-	epoch := core.CurrentEpoch(state)
-	indices, err := ActiveValidatorIndices(state, epoch)
+	epoch := time.CurrentEpoch(state)
+	indices, err := ActiveValidatorIndices(context.Background(), state, epoch)
 	require.NoError(b, err)
 	seed, err := Seed(state, epoch, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(b, err)
@@ -584,13 +586,13 @@ func TestBeaconCommitteeFromState_UpdateCacheForPreviousEpoch(t *testing.T) {
 		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
 	})
 	require.NoError(t, err)
-	_, err = BeaconCommitteeFromState(state, 1 /* previous epoch */, 0)
+	_, err = BeaconCommitteeFromState(context.Background(), state, 1 /* previous epoch */, 0)
 	require.NoError(t, err)
 
 	// Verify previous epoch is cached
 	seed, err := Seed(state, 0, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(t, err)
-	activeIndices, err := committeeCache.ActiveIndices(seed)
+	activeIndices, err := committeeCache.ActiveIndices(context.Background(), seed)
 	require.NoError(t, err)
 	assert.NotNil(t, activeIndices, "Did not cache active indices")
 }
@@ -609,7 +611,7 @@ func TestPrecomputeProposerIndices_Ok(t *testing.T) {
 	})
 	require.NoError(t, err)
 
-	indices, err := ActiveValidatorIndices(state, 0)
+	indices, err := ActiveValidatorIndices(context.Background(), state, 0)
 	require.NoError(t, err)
 
 	proposerIndices, err := precomputeProposerIndices(state, indices)

beacon-chain/core/helpers/block.go

@@ -5,10 +5,10 @@ import (
 
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1/block"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // VerifyNilBeaconBlock checks if any composite field of input signed beacon block is nil.
@@ -65,7 +65,7 @@ func StateRootAtSlot(state state.ReadOnlyBeaconState, slot types.Slot) ([]byte,
 //    """
 //    return get_block_root_at_slot(state, compute_start_slot_at_epoch(epoch))
 func BlockRoot(state state.ReadOnlyBeaconState, epoch types.Epoch) ([]byte, error) {
-	s, err := core.StartSlot(epoch)
+	s, err := slots.EpochStart(epoch)
 	if err != nil {
 		return nil, err
 	}

beacon-chain/core/helpers/rewards_penalties.go

@@ -5,9 +5,10 @@ import (
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
+	mathutil "github.com/prysmaticlabs/prysm/math"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 var balanceCache = cache.NewEffectiveBalanceCache()
@@ -65,7 +66,7 @@ func TotalActiveBalance(s state.ReadOnlyBeaconState) (uint64, error) {
 	}
 
 	total := uint64(0)
-	epoch := core.SlotToEpoch(s.Slot())
+	epoch := slots.ToEpoch(s.Slot())
 	if err := s.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
 		if IsActiveValidatorUsingTrie(val, epoch) {
 			total += val.EffectiveBalance()
@@ -95,7 +96,11 @@ func IncreaseBalance(state state.BeaconState, idx types.ValidatorIndex, delta ui
 	if err != nil {
 		return err
 	}
-	return state.UpdateBalancesAtIndex(idx, IncreaseBalanceWithVal(balAtIdx, delta))
+	newBal, err := IncreaseBalanceWithVal(balAtIdx, delta)
+	if err != nil {
+		return err
+	}
+	return state.UpdateBalancesAtIndex(idx, newBal)
 }
 
 // IncreaseBalanceWithVal increases validator with the given 'index' balance by 'delta' in Gwei.
@@ -108,8 +113,8 @@ func IncreaseBalance(state state.BeaconState, idx types.ValidatorIndex, delta ui
 //    Increase the validator balance at index ``index`` by ``delta``.
 //    """
 //    state.balances[index] += delta
-func IncreaseBalanceWithVal(currBalance, delta uint64) uint64 {
-	return currBalance + delta
+func IncreaseBalanceWithVal(currBalance, delta uint64) (uint64, error) {
+	return mathutil.Add64(currBalance, delta)
 }
 
 // DecreaseBalance decreases validator with the given 'index' balance by 'delta' in Gwei.

beacon-chain/core/helpers/rewards_penalties_test.go

@@ -1,10 +1,11 @@
 package helpers
 
 import (
+	"math"
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/features"
 	"github.com/prysmaticlabs/prysm/config/params"
@@ -157,24 +158,24 @@ func TestFinalityDelay(t *testing.T) {
 	finalizedEpoch := types.Epoch(0)
 	// Set values for each test case
 	setVal := func() {
-		prevEpoch = core.PrevEpoch(beaconState)
+		prevEpoch = time.PrevEpoch(beaconState)
 		finalizedEpoch = beaconState.FinalizedCheckpointEpoch()
 	}
 	setVal()
 	d := FinalityDelay(prevEpoch, finalizedEpoch)
-	w := core.PrevEpoch(beaconState) - beaconState.FinalizedCheckpointEpoch()
+	w := time.PrevEpoch(beaconState) - beaconState.FinalizedCheckpointEpoch()
 	assert.Equal(t, w, d, "Did not get wanted finality delay")
 
 	require.NoError(t, beaconState.SetFinalizedCheckpoint(&ethpb.Checkpoint{Epoch: 4}))
 	setVal()
 	d = FinalityDelay(prevEpoch, finalizedEpoch)
-	w = core.PrevEpoch(beaconState) - beaconState.FinalizedCheckpointEpoch()
+	w = time.PrevEpoch(beaconState) - beaconState.FinalizedCheckpointEpoch()
 	assert.Equal(t, w, d, "Did not get wanted finality delay")
 
 	require.NoError(t, beaconState.SetFinalizedCheckpoint(&ethpb.Checkpoint{Epoch: 5}))
 	setVal()
 	d = FinalityDelay(prevEpoch, finalizedEpoch)
-	w = core.PrevEpoch(beaconState) - beaconState.FinalizedCheckpointEpoch()
+	w = time.PrevEpoch(beaconState) - beaconState.FinalizedCheckpointEpoch()
 	assert.Equal(t, w, d, "Did not get wanted finality delay")
 }
 
@@ -187,7 +188,7 @@ func TestIsInInactivityLeak(t *testing.T) {
 	finalizedEpoch := types.Epoch(0)
 	// Set values for each test case
 	setVal := func() {
-		prevEpoch = core.PrevEpoch(beaconState)
+		prevEpoch = time.PrevEpoch(beaconState)
 		finalizedEpoch = beaconState.FinalizedCheckpointEpoch()
 	}
 	setVal()
@@ -238,3 +239,23 @@ func buildState(slot types.Slot, validatorCount uint64) *ethpb.BeaconState {
 		CurrentJustifiedCheckpoint:  &ethpb.Checkpoint{Root: make([]byte, 32)},
 	}
 }
+
+func TestIncreaseBadBalance_NotOK(t *testing.T) {
+	tests := []struct {
+		i  types.ValidatorIndex
+		b  []uint64
+		nb uint64
+	}{
+		{i: 0, b: []uint64{math.MaxUint64, math.MaxUint64, math.MaxUint64}, nb: 1},
+		{i: 2, b: []uint64{math.MaxUint64, math.MaxUint64, math.MaxUint64}, nb: 33 * 1e9},
+	}
+	for _, test := range tests {
+		state, err := v1.InitializeFromProto(&ethpb.BeaconState{
+			Validators: []*ethpb.Validator{
+				{EffectiveBalance: 4}, {EffectiveBalance: 4}, {EffectiveBalance: 4}},
+			Balances: test.b,
+		})
+		require.NoError(t, err)
+		require.ErrorContains(t, "addition overflows", IncreaseBalance(state, test.i, test.nb))
+	}
+}

beacon-chain/core/helpers/sync_committee.go

@@ -8,10 +8,11 @@ import (
 	"github.com/pkg/errors"
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/time/slots"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -154,7 +155,7 @@ func UpdateSyncCommitteeCache(st state.BeaconStateAltair) error {
 	if nextSlot%params.BeaconConfig().SlotsPerEpoch != 0 {
 		return errors.New("not at the end of the epoch to update cache")
 	}
-	if core.SlotToEpoch(nextSlot)%params.BeaconConfig().EpochsPerSyncCommitteePeriod != 0 {
+	if slots.ToEpoch(nextSlot)%params.BeaconConfig().EpochsPerSyncCommitteePeriod != 0 {
 		return errors.New("not at sync committee period boundary to update cache")
 	}
 
@@ -191,11 +192,11 @@ func syncPeriodBoundaryRoot(st state.ReadOnlyBeaconState) ([]byte, error) {
 		return params.BeaconConfig().ZeroHash[:], nil
 	}
 
-	startEpoch, err := core.SyncCommitteePeriodStartEpoch(core.CurrentEpoch(st))
+	startEpoch, err := slots.SyncCommitteePeriodStartEpoch(time.CurrentEpoch(st))
 	if err != nil {
 		return nil, err
 	}
-	startEpochSlot, err := core.StartSlot(startEpoch)
+	startEpochSlot, err := slots.EpochStart(startEpoch)
 	if err != nil {
 		return nil, err
 	}

beacon-chain/core/helpers/validators.go

@@ -2,18 +2,28 @@ package helpers
 
 import (
 	"bytes"
+	"context"
 
 	"github.com/pkg/errors"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
-	"github.com/prysmaticlabs/prysm/crypto/bls"
 	"github.com/prysmaticlabs/prysm/crypto/hash"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
+	log "github.com/sirupsen/logrus"
 )
 
+var CommitteeCacheInProgressHit = promauto.NewCounter(prometheus.CounterOpts{
+	Name: "committee_cache_in_progress_hit",
+	Help: "The number of committee requests that are present in the cache.",
+})
+
 // IsActiveValidator returns the boolean value on whether the validator
 // is active or not.
 //
@@ -73,18 +83,39 @@ func checkValidatorSlashable(activationEpoch, withdrawableEpoch types.Epoch, sla
 //    Return the sequence of active validator indices at ``epoch``.
 //    """
 //    return [ValidatorIndex(i) for i, v in enumerate(state.validators) if is_active_validator(v, epoch)]
-func ActiveValidatorIndices(s state.ReadOnlyBeaconState, epoch types.Epoch) ([]types.ValidatorIndex, error) {
+func ActiveValidatorIndices(ctx context.Context, s state.ReadOnlyBeaconState, epoch types.Epoch) ([]types.ValidatorIndex, error) {
 	seed, err := Seed(s, epoch, params.BeaconConfig().DomainBeaconAttester)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get seed")
 	}
-	activeIndices, err := committeeCache.ActiveIndices(seed)
+	activeIndices, err := committeeCache.ActiveIndices(ctx, seed)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not interface with committee cache")
 	}
 	if activeIndices != nil {
 		return activeIndices, nil
 	}
+
+	if err := committeeCache.MarkInProgress(seed); err != nil {
+		if errors.Is(err, cache.ErrAlreadyInProgress) {
+			activeIndices, err := committeeCache.ActiveIndices(ctx, seed)
+			if err != nil {
+				return nil, err
+			}
+			if activeIndices == nil {
+				return nil, errors.New("nil active indices")
+			}
+			CommitteeCacheInProgressHit.Inc()
+			return activeIndices, nil
+		}
+		return nil, errors.Wrap(err, "could not mark committee cache as in progress")
+	}
+	defer func() {
+		if err := committeeCache.MarkNotInProgress(seed); err != nil {
+			log.WithError(err).Error("Could not mark cache not in progress")
+		}
+	}()
+
 	var indices []types.ValidatorIndex
 	if err := s.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
 		if IsActiveValidatorUsingTrie(val, epoch) {
@@ -104,12 +135,12 @@ func ActiveValidatorIndices(s state.ReadOnlyBeaconState, epoch types.Epoch) ([]t
 
 // ActiveValidatorCount returns the number of active validators in the state
 // at the given epoch.
-func ActiveValidatorCount(s state.ReadOnlyBeaconState, epoch types.Epoch) (uint64, error) {
+func ActiveValidatorCount(ctx context.Context, s state.ReadOnlyBeaconState, epoch types.Epoch) (uint64, error) {
 	seed, err := Seed(s, epoch, params.BeaconConfig().DomainBeaconAttester)
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get seed")
 	}
-	activeCount, err := committeeCache.ActiveIndicesCount(seed)
+	activeCount, err := committeeCache.ActiveIndicesCount(ctx, seed)
 	if err != nil {
 		return 0, errors.Wrap(err, "could not interface with committee cache")
 	}
@@ -117,6 +148,23 @@ func ActiveValidatorCount(s state.ReadOnlyBeaconState, epoch types.Epoch) (uint6
 		return uint64(activeCount), nil
 	}
 
+	if err := committeeCache.MarkInProgress(seed); err != nil {
+		if errors.Is(err, cache.ErrAlreadyInProgress) {
+			activeCount, err := committeeCache.ActiveIndicesCount(ctx, seed)
+			if err != nil {
+				return 0, err
+			}
+			CommitteeCacheInProgressHit.Inc()
+			return uint64(activeCount), nil
+		}
+		return 0, errors.Wrap(err, "could not mark committee cache as in progress")
+	}
+	defer func() {
+		if err := committeeCache.MarkNotInProgress(seed); err != nil {
+			log.WithError(err).Error("Could not mark cache not in progress")
+		}
+	}()
+
 	count := uint64(0)
 	if err := s.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
 		if IsActiveValidatorUsingTrie(val, epoch) {
@@ -176,16 +224,13 @@ func ValidatorChurnLimit(activeValidatorCount uint64) (uint64, error) {
 //    seed = hash(get_seed(state, epoch, DOMAIN_BEACON_PROPOSER) + uint_to_bytes(state.slot))
 //    indices = get_active_validator_indices(state, epoch)
 //    return compute_proposer_index(state, indices, seed)
-func BeaconProposerIndex(state state.ReadOnlyBeaconState) (types.ValidatorIndex, error) {
-	e := core.CurrentEpoch(state)
+func BeaconProposerIndex(ctx context.Context, state state.ReadOnlyBeaconState) (types.ValidatorIndex, error) {
+	e := time.CurrentEpoch(state)
 	// The cache uses the state root of the previous epoch - minimum_seed_lookahead last slot as key. (e.g. Starting epoch 1, slot 32, the key would be block root at slot 31)
 	// For simplicity, the node will skip caching of genesis epoch.
 	if e > params.BeaconConfig().GenesisEpoch+params.BeaconConfig().MinSeedLookahead {
-		wantedEpoch := core.PrevEpoch(state)
-		if wantedEpoch >= params.BeaconConfig().MinSeedLookahead {
-			wantedEpoch -= params.BeaconConfig().MinSeedLookahead
-		}
-		s, err := core.EndSlot(wantedEpoch)
+		wantedEpoch := time.PrevEpoch(state)
+		s, err := slots.EpochEnd(wantedEpoch)
 		if err != nil {
 			return 0, err
 		}
@@ -204,7 +249,7 @@ func BeaconProposerIndex(state state.ReadOnlyBeaconState) (types.ValidatorIndex,
 				}
 				return proposerIndices[state.Slot()%params.BeaconConfig().SlotsPerEpoch], nil
 			}
-			if err := UpdateProposerIndicesInCache(state); err != nil {
+			if err := UpdateProposerIndicesInCache(ctx, state); err != nil {
 				return 0, errors.Wrap(err, "could not update committee cache")
 			}
 		}
@@ -218,7 +263,7 @@ func BeaconProposerIndex(state state.ReadOnlyBeaconState) (types.ValidatorIndex,
 	seedWithSlot := append(seed[:], bytesutil.Bytes8(uint64(state.Slot()))...)
 	seedWithSlotHash := hash.Hash(seedWithSlot)
 
-	indices, err := ActiveValidatorIndices(state, e)
+	indices, err := ActiveValidatorIndices(ctx, state, e)
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get active indices")
 	}
@@ -275,34 +320,6 @@ func ComputeProposerIndex(bState state.ReadOnlyValidators, activeIndices []types
 	}
 }
 
-// Domain returns the domain version for BLS private key to sign and verify.
-//
-// Spec pseudocode definition:
-//  def get_domain(state: BeaconState, domain_type: DomainType, epoch: Epoch=None) -> Domain:
-//    """
-//    Return the signature domain (fork version concatenated with domain type) of a message.
-//    """
-//    epoch = get_current_epoch(state) if epoch is None else epoch
-//    fork_version = state.fork.previous_version if epoch < state.fork.epoch else state.fork.current_version
-//    return compute_domain(domain_type, fork_version, state.genesis_validators_root)
-func Domain(fork *ethpb.Fork, epoch types.Epoch, domainType [bls.DomainByteLength]byte, genesisRoot []byte) ([]byte, error) {
-	if fork == nil {
-		return []byte{}, errors.New("nil fork or domain type")
-	}
-	var forkVersion []byte
-	if epoch < fork.Epoch {
-		forkVersion = fork.PreviousVersion
-	} else {
-		forkVersion = fork.CurrentVersion
-	}
-	if len(forkVersion) != 4 {
-		return []byte{}, errors.New("fork version length is not 4 byte")
-	}
-	var forkVersionArray [4]byte
-	copy(forkVersionArray[:], forkVersion[:4])
-	return ComputeDomain(domainType, forkVersionArray[:], genesisRoot)
-}
-
 // IsEligibleForActivationQueue checks if the validator is eligible to
 // be placed into the activation queue.
 //

beacon-chain/core/helpers/validators_test.go

@@ -1,12 +1,13 @@
 package helpers
 
 import (
+	"context"
 	"errors"
 	"testing"
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/hash"
@@ -270,7 +271,7 @@ func TestBeaconProposerIndex_OK(t *testing.T) {
 	for _, tt := range tests {
 		ClearCache()
 		require.NoError(t, state.SetSlot(tt.slot))
-		result, err := BeaconProposerIndex(state)
+		result, err := BeaconProposerIndex(context.Background(), state)
 		require.NoError(t, err, "Failed to get shard and committees at slot")
 		assert.Equal(t, tt.index, result, "Result index was an unexpected value")
 	}
@@ -304,7 +305,7 @@ func TestBeaconProposerIndex_BadState(t *testing.T) {
 	// Set a very high slot, so that retrieved block root will be
 	// non existent for the proposer cache.
 	require.NoError(t, state.SetSlot(100))
-	_, err = BeaconProposerIndex(state)
+	_, err = BeaconProposerIndex(context.Background(), state)
 	require.NoError(t, err)
 	assert.Equal(t, 0, len(proposerIndicesCache.ProposerIndicesCache.ListKeys()))
 }
@@ -323,7 +324,7 @@ func TestComputeProposerIndex_Compatibility(t *testing.T) {
 	})
 	require.NoError(t, err)
 
-	indices, err := ActiveValidatorIndices(state, 0)
+	indices, err := ActiveValidatorIndices(context.Background(), state, 0)
 	require.NoError(t, err)
 
 	var proposerIndices []types.ValidatorIndex
@@ -375,7 +376,7 @@ func TestActiveValidatorCount_Genesis(t *testing.T) {
 	seed, err := Seed(beaconState, 0, params.BeaconConfig().DomainBeaconAttester)
 	require.NoError(t, err)
 	require.NoError(t, committeeCache.AddCommitteeShuffledList(&cache.Committees{Seed: seed, ShuffledIndices: []types.ValidatorIndex{1, 2, 3}}))
-	validatorCount, err := ActiveValidatorCount(beaconState, core.CurrentEpoch(beaconState))
+	validatorCount, err := ActiveValidatorCount(context.Background(), beaconState, time.CurrentEpoch(beaconState))
 	require.NoError(t, err)
 	assert.Equal(t, uint64(c), validatorCount, "Did not get the correct validator count")
 }
@@ -406,7 +407,7 @@ func TestChurnLimit_OK(t *testing.T) {
 			RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
 		})
 		require.NoError(t, err)
-		validatorCount, err := ActiveValidatorCount(beaconState, core.CurrentEpoch(beaconState))
+		validatorCount, err := ActiveValidatorCount(context.Background(), beaconState, time.CurrentEpoch(beaconState))
 		require.NoError(t, err)
 		resultChurn, err := ValidatorChurnLimit(validatorCount)
 		require.NoError(t, err)
@@ -414,32 +415,6 @@ func TestChurnLimit_OK(t *testing.T) {
 	}
 }
 
-func TestDomain_OK(t *testing.T) {
-	state := &ethpb.BeaconState{
-		Fork: &ethpb.Fork{
-			Epoch:           3,
-			PreviousVersion: []byte{0, 0, 0, 2},
-			CurrentVersion:  []byte{0, 0, 0, 3},
-		},
-	}
-	tests := []struct {
-		epoch      types.Epoch
-		domainType [4]byte
-		result     []byte
-	}{
-		{epoch: 1, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(4)), result: bytesutil.ToBytes(947067381421703172, 32)},
-		{epoch: 2, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(4)), result: bytesutil.ToBytes(947067381421703172, 32)},
-		{epoch: 2, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(5)), result: bytesutil.ToBytes(947067381421703173, 32)},
-		{epoch: 3, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(4)), result: bytesutil.ToBytes(9369798235163459588, 32)},
-		{epoch: 3, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(5)), result: bytesutil.ToBytes(9369798235163459589, 32)},
-	}
-	for _, tt := range tests {
-		domain, err := Domain(state.Fork, tt.epoch, tt.domainType, nil)
-		require.NoError(t, err)
-		assert.DeepEqual(t, tt.result[:8], domain[:8], "Unexpected domain version")
-	}
-}
-
 // Test basic functionality of ActiveValidatorIndices without caching. This test will need to be
 // rewritten when releasing some cache flag.
 func TestActiveValidatorIndices(t *testing.T) {
@@ -591,7 +566,7 @@ func TestActiveValidatorIndices(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			s, err := v1.InitializeFromProto(tt.args.state)
 			require.NoError(t, err)
-			got, err := ActiveValidatorIndices(s, tt.args.epoch)
+			got, err := ActiveValidatorIndices(context.Background(), s, tt.args.epoch)
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 				return

beacon-chain/core/helpers/weak_subjectivity.go

@@ -2,6 +2,7 @@ package helpers
 
 import (
 	"bytes"
+	"context"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -9,11 +10,12 @@ import (
 	"strings"
 
 	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/math"
 	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 // ComputeWeakSubjectivityPeriod returns weak subjectivity period for the active validator count and finalized epoch.
@@ -52,12 +54,12 @@ import (
 //        )
 //
 //    return ws_period
-func ComputeWeakSubjectivityPeriod(st state.ReadOnlyBeaconState) (types.Epoch, error) {
+func ComputeWeakSubjectivityPeriod(ctx context.Context, st state.ReadOnlyBeaconState) (types.Epoch, error) {
 	// Weak subjectivity period cannot be smaller than withdrawal delay.
 	wsp := uint64(params.BeaconConfig().MinValidatorWithdrawabilityDelay)
 
 	// Cardinality of active validator set.
-	N, err := ActiveValidatorCount(st, core.CurrentEpoch(st))
+	N, err := ActiveValidatorCount(ctx, st, time.CurrentEpoch(st))
 	if err != nil {
 		return 0, fmt.Errorf("cannot obtain active valiadtor count: %w", err)
 	}
@@ -120,7 +122,7 @@ func ComputeWeakSubjectivityPeriod(st state.ReadOnlyBeaconState) (types.Epoch, e
 //    current_epoch = compute_epoch_at_slot(get_current_slot(store))
 //    return current_epoch <= ws_state_epoch + ws_period
 func IsWithinWeakSubjectivityPeriod(
-	currentEpoch types.Epoch, wsState state.ReadOnlyBeaconState, wsCheckpoint *eth.WeakSubjectivityCheckpoint) (bool, error) {
+	ctx context.Context, currentEpoch types.Epoch, wsState state.ReadOnlyBeaconState, wsCheckpoint *eth.WeakSubjectivityCheckpoint) (bool, error) {
 	// Make sure that incoming objects are not nil.
 	if wsState == nil || wsState.IsNil() || wsState.LatestBlockHeader() == nil || wsCheckpoint == nil {
 		return false, errors.New("invalid weak subjectivity state or checkpoint")
@@ -131,17 +133,17 @@ func IsWithinWeakSubjectivityPeriod(
 		return false, fmt.Errorf("state (%#x) and checkpoint (%#x) roots do not match",
 			wsState.LatestBlockHeader().StateRoot, wsCheckpoint.StateRoot)
 	}
-	if core.SlotToEpoch(wsState.Slot()) != wsCheckpoint.Epoch {
+	if slots.ToEpoch(wsState.Slot()) != wsCheckpoint.Epoch {
 		return false, fmt.Errorf("state (%v) and checkpoint (%v) epochs do not match",
-			core.SlotToEpoch(wsState.Slot()), wsCheckpoint.Epoch)
+			slots.ToEpoch(wsState.Slot()), wsCheckpoint.Epoch)
 	}
 
 	// Compare given epoch to state epoch + weak subjectivity period.
-	wsPeriod, err := ComputeWeakSubjectivityPeriod(wsState)
+	wsPeriod, err := ComputeWeakSubjectivityPeriod(ctx, wsState)
 	if err != nil {
 		return false, fmt.Errorf("cannot compute weak subjectivity period: %w", err)
 	}
-	wsStateEpoch := core.SlotToEpoch(wsState.Slot())
+	wsStateEpoch := slots.ToEpoch(wsState.Slot())
 
 	return currentEpoch <= wsStateEpoch+wsPeriod, nil
 }
@@ -151,8 +153,8 @@ func IsWithinWeakSubjectivityPeriod(
 // Within the weak subjectivity period, if two conflicting blocks are finalized, 1/3 - D (D := safety decay)
 // of validators will get slashed. Therefore, it is safe to assume that any finalized checkpoint within that
 // period is protected by this safety margin.
-func LatestWeakSubjectivityEpoch(st state.ReadOnlyBeaconState) (types.Epoch, error) {
-	wsPeriod, err := ComputeWeakSubjectivityPeriod(st)
+func LatestWeakSubjectivityEpoch(ctx context.Context, st state.ReadOnlyBeaconState) (types.Epoch, error) {
+	wsPeriod, err := ComputeWeakSubjectivityPeriod(ctx, st)
 	if err != nil {
 		return 0, err
 	}

beacon-chain/core/helpers/weak_subjectivity_test.go

@@ -1,6 +1,7 @@
 package helpers_test
 
 import (
+	"context"
 	"fmt"
 	"testing"
 
@@ -47,7 +48,7 @@ func TestWeakSubjectivity_ComputeWeakSubjectivityPeriod(t *testing.T) {
 		t.Run(fmt.Sprintf("valCount: %d, avgBalance: %d", tt.valCount, tt.avgBalance), func(t *testing.T) {
 			// Reset committee cache - as we need to recalculate active validator set for each test.
 			helpers.ClearCache()
-			got, err := helpers.ComputeWeakSubjectivityPeriod(genState(t, tt.valCount, tt.avgBalance))
+			got, err := helpers.ComputeWeakSubjectivityPeriod(context.Background(), genState(t, tt.valCount, tt.avgBalance))
 			require.NoError(t, err)
 			assert.Equal(t, tt.want, got, "valCount: %v, avgBalance: %v", tt.valCount, tt.avgBalance)
 		})
@@ -192,7 +193,7 @@ func TestWeakSubjectivity_IsWithinWeakSubjectivityPeriod(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := helpers.IsWithinWeakSubjectivityPeriod(tt.epoch, tt.genWsState(), tt.genWsCheckpoint())
+			got, err := helpers.IsWithinWeakSubjectivityPeriod(context.Background(), tt.epoch, tt.genWsState(), tt.genWsCheckpoint())
 			if tt.wantedErr != "" {
 				assert.Equal(t, false, got)
 				assert.ErrorContains(t, tt.wantedErr, err)

beacon-chain/core/signing/BUILD.bazel

@@ -0,0 +1,44 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "domain.go",
+        "signing_root.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/core/signing",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/state:go_default_library",
+        "//config/params:go_default_library",
+        "//crypto/bls:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "@com_github_ferranbt_fastssz//:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prysmaticlabs_eth2_types//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "domain_test.go",
+        "signing_root_test.go",
+    ],
+    embed = [":go_default_library"],
+    deps = [
+        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
+        "//beacon-chain/state:go_default_library",
+        "//config/params:go_default_library",
+        "//crypto/bls:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+        "@com_github_google_gofuzz//:go_default_library",
+        "@com_github_prysmaticlabs_eth2_types//:go_default_library",
+    ],
+)

beacon-chain/core/signing/domain.go

@@ -0,0 +1,36 @@
+package signing
+
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/eth2-types"
+	"github.com/prysmaticlabs/prysm/crypto/bls"
+	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+)
+
+// Domain returns the domain version for BLS private key to sign and verify.
+//
+// Spec pseudocode definition:
+//  def get_domain(state: BeaconState, domain_type: DomainType, epoch: Epoch=None) -> Domain:
+//    """
+//    Return the signature domain (fork version concatenated with domain type) of a message.
+//    """
+//    epoch = get_current_epoch(state) if epoch is None else epoch
+//    fork_version = state.fork.previous_version if epoch < state.fork.epoch else state.fork.current_version
+//    return compute_domain(domain_type, fork_version, state.genesis_validators_root)
+func Domain(fork *eth.Fork, epoch types.Epoch, domainType [bls.DomainByteLength]byte, genesisRoot []byte) ([]byte, error) {
+	if fork == nil {
+		return []byte{}, errors.New("nil fork or domain type")
+	}
+	var forkVersion []byte
+	if epoch < fork.Epoch {
+		forkVersion = fork.PreviousVersion
+	} else {
+		forkVersion = fork.CurrentVersion
+	}
+	if len(forkVersion) != 4 {
+		return []byte{}, errors.New("fork version length is not 4 byte")
+	}
+	var forkVersionArray [4]byte
+	copy(forkVersionArray[:], forkVersion[:4])
+	return ComputeDomain(domainType, forkVersionArray[:], genesisRoot)
+}

beacon-chain/core/signing/domain_test.go

@@ -0,0 +1,37 @@
+package signing
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/eth2-types"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/assert"
+	"github.com/prysmaticlabs/prysm/testing/require"
+)
+
+func TestDomain_OK(t *testing.T) {
+	state := &eth.BeaconState{
+		Fork: &eth.Fork{
+			Epoch:           3,
+			PreviousVersion: []byte{0, 0, 0, 2},
+			CurrentVersion:  []byte{0, 0, 0, 3},
+		},
+	}
+	tests := []struct {
+		epoch      types.Epoch
+		domainType [4]byte
+		result     []byte
+	}{
+		{epoch: 1, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(4)), result: bytesutil.ToBytes(947067381421703172, 32)},
+		{epoch: 2, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(4)), result: bytesutil.ToBytes(947067381421703172, 32)},
+		{epoch: 2, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(5)), result: bytesutil.ToBytes(947067381421703173, 32)},
+		{epoch: 3, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(4)), result: bytesutil.ToBytes(9369798235163459588, 32)},
+		{epoch: 3, domainType: bytesutil.ToBytes4(bytesutil.Bytes4(5)), result: bytesutil.ToBytes(9369798235163459589, 32)},
+	}
+	for _, tt := range tests {
+		domain, err := Domain(state.Fork, tt.epoch, tt.domainType, nil)
+		require.NoError(t, err)
+		assert.DeepEqual(t, tt.result[:8], domain[:8], "Unexpected domain version")
+	}
+}

beacon-chain/core/signing/signing_root.go

@@ -1,4 +1,4 @@
-package helpers
+package signing
 
 import (
 	fssz "github.com/ferranbt/fastssz"
@@ -64,7 +64,7 @@ func signingData(rootFunc func() ([32]byte, error), domain []byte) ([32]byte, er
 }
 
 // ComputeDomainVerifySigningRoot computes domain and verifies signing root of an object given the beacon state, validator index and signature.
-func ComputeDomainVerifySigningRoot(st state.BeaconState, index types.ValidatorIndex, epoch types.Epoch, obj fssz.HashRoot, domain [4]byte, sig []byte) error {
+func ComputeDomainVerifySigningRoot(st state.ReadOnlyBeaconState, index types.ValidatorIndex, epoch types.Epoch, obj fssz.HashRoot, domain [4]byte, sig []byte) error {
 	v, err := st.ValidatorAtIndex(index)
 	if err != nil {
 		return err
@@ -76,7 +76,7 @@ func ComputeDomainVerifySigningRoot(st state.BeaconState, index types.ValidatorI
 	return VerifySigningRoot(obj, v.PublicKey, sig, d)
 }
 
-// VerifySigningRoot verifies the signing root of an object given it's public key, signature and domain.
+// VerifySigningRoot verifies the signing root of an object given its public key, signature and domain.
 func VerifySigningRoot(obj fssz.HashRoot, pub, signature, domain []byte) error {
 	publicKey, err := bls.PublicKeyFromBytes(pub)
 	if err != nil {
@@ -96,7 +96,27 @@ func VerifySigningRoot(obj fssz.HashRoot, pub, signature, domain []byte) error {
 	return nil
 }
 
-// VerifyBlockSigningRoot verifies the signing root of a block given it's public key, signature and domain.
+// VerifyBlockHeaderSigningRoot verifies the signing root of a block header given its public key, signature and domain.
+func VerifyBlockHeaderSigningRoot(blkHdr *ethpb.BeaconBlockHeader, pub, signature, 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 := signingData(blkHdr.HashTreeRoot, domain)
+	if err != nil {
+		return errors.Wrap(err, "could not compute signing root")
+	}
+	if !sig.Verify(publicKey, root[:]) {
+		return ErrSigFailedToVerify
+	}
+	return nil
+}
+
+// VerifyBlockSigningRoot verifies the signing root of a block given its public key, signature and domain.
 func VerifyBlockSigningRoot(pub, signature, domain []byte, rootFunc func() ([32]byte, error)) error {
 	set, err := BlockSignatureSet(pub, signature, domain, rootFunc)
 	if err != nil {

beacon-chain/core/signing/signing_root_test.go

@@ -1,12 +1,14 @@
-package helpers_test
+package signing_test
 
 import (
 	"bytes"
+	"context"
 	"testing"
 
 	fuzz "github.com/google/gofuzz"
-	"github.com/prysmaticlabs/prysm/beacon-chain/core"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/crypto/bls"
@@ -20,7 +22,7 @@ import (
 
 func TestSigningRoot_ComputeSigningRoot(t *testing.T) {
 	emptyBlock := util.NewBeaconBlock()
-	_, err := helpers.ComputeSigningRoot(emptyBlock, bytesutil.PadTo([]byte{'T', 'E', 'S', 'T'}, 32))
+	_, err := signing.ComputeSigningRoot(emptyBlock, bytesutil.PadTo([]byte{'T', 'E', 'S', 'T'}, 32))
 	assert.NoError(t, err, "Could not compute signing root of block")
 }
 
@@ -37,7 +39,7 @@ func TestSigningRoot_ComputeDomain(t *testing.T) {
 		{epoch: 3, domainType: [4]byte{5, 0, 0, 0}, domain: []byte{5, 0, 0, 0, 245, 165, 253, 66, 209, 106, 32, 48, 39, 152, 239, 110, 211, 9, 151, 155, 67, 0, 61, 35, 32, 217, 240, 232, 234, 152, 49, 169}},
 	}
 	for _, tt := range tests {
-		if got, err := helpers.ComputeDomain(tt.domainType, nil, nil); !bytes.Equal(got, tt.domain) {
+		if got, err := signing.ComputeDomain(tt.domainType, nil, nil); !bytes.Equal(got, tt.domain) {
 			t.Errorf("wanted domain version: %d, got: %d", tt.domain, got)
 		} else {
 			require.NoError(t, err)
@@ -80,11 +82,11 @@ func TestSigningRoot_ComputeDomainAndSign(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			beaconState, privKeys := tt.genState(t)
-			idx, err := helpers.BeaconProposerIndex(beaconState)
+			idx, err := helpers.BeaconProposerIndex(context.Background(), beaconState)
 			require.NoError(t, err)
 			block := tt.genBlock(t, beaconState, privKeys)
-			got, err := helpers.ComputeDomainAndSign(
-				beaconState, core.CurrentEpoch(beaconState), block, tt.domainType, privKeys[idx])
+			got, err := signing.ComputeDomainAndSign(
+				beaconState, time.CurrentEpoch(beaconState), block, tt.domainType, privKeys[idx])
 			require.NoError(t, err)
 			require.DeepEqual(t, tt.want, got, "Incorrect signature")
 		})
@@ -102,7 +104,7 @@ func TestSigningRoot_ComputeForkDigest(t *testing.T) {
 		{version: []byte{'b', 'w', 'r', 't'}, root: [32]byte{'r', 'd', 'c'}, result: [4]byte{0x83, 0x34, 0x38, 0x88}},
 	}
 	for _, tt := range tests {
-		digest, err := helpers.ComputeForkDigest(tt.version, tt.root[:])
+		digest, err := signing.ComputeForkDigest(tt.version, tt.root[:])
 		require.NoError(t, err)
 		assert.Equal(t, tt.result, digest, "Wanted domain version: %#x, got: %#x", digest, tt.result)
 	}
@@ -126,9 +128,9 @@ func TestFuzzverifySigningRoot_10000(_ *testing.T) {
 		fuzzer.Fuzz(&p)
 		fuzzer.Fuzz(&s)
 		fuzzer.Fuzz(&d)
-		err := helpers.VerifySigningRoot(state, pubkey[:], sig[:], domain[:])
+		err := signing.VerifySigningRoot(state, pubkey[:], sig[:], domain[:])
 		_ = err
-		err = helpers.VerifySigningRoot(state, p, s, d)
+		err = signing.VerifySigningRoot(state, p, s, d)
 		_ = err
 	}
 }

beacon-chain/core/slot_epoch.go

@@ -1,238 +0,0 @@
-package core
-
-import (
-	"fmt"
-	"math"
-	"time"
-
-	math2 "github.com/ethereum/go-ethereum/common/math"
-	"github.com/pkg/errors"
-	types "github.com/prysmaticlabs/eth2-types"
-	"github.com/prysmaticlabs/prysm/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/config/params"
-	"github.com/prysmaticlabs/prysm/runtime/version"
-	prysmTime "github.com/prysmaticlabs/prysm/time"
-)
-
-// MaxSlotBuffer specifies the max buffer given to slots from
-// incoming objects. (24 mins with mainnet spec)
-const MaxSlotBuffer = uint64(1 << 7)
-
-// SlotToEpoch returns the epoch number of the input slot.
-//
-// Spec pseudocode definition:
-//  def compute_epoch_at_slot(slot: Slot) -> Epoch:
-//    """
-//    Return the epoch number at ``slot``.
-//    """
-//    return Epoch(slot // SLOTS_PER_EPOCH)
-func SlotToEpoch(slot types.Slot) types.Epoch {
-	return types.Epoch(slot.DivSlot(params.BeaconConfig().SlotsPerEpoch))
-}
-
-// CurrentEpoch returns the current epoch number calculated from
-// the slot number stored in beacon state.
-//
-// Spec pseudocode definition:
-//  def get_current_epoch(state: BeaconState) -> Epoch:
-//    """
-//    Return the current epoch.
-//    """
-//    return compute_epoch_at_slot(state.slot)
-func CurrentEpoch(state state.ReadOnlyBeaconState) types.Epoch {
-	return SlotToEpoch(state.Slot())
-}
-
-// PrevEpoch returns the previous epoch number calculated from
-// the slot number stored in beacon state. It also checks for
-// underflow condition.
-//
-// Spec pseudocode definition:
-//  def get_previous_epoch(state: BeaconState) -> Epoch:
-//    """`
-//    Return the previous epoch (unless the current epoch is ``GENESIS_EPOCH``).
-//    """
-//    current_epoch = get_current_epoch(state)
-//    return GENESIS_EPOCH if current_epoch == GENESIS_EPOCH else Epoch(current_epoch - 1)
-func PrevEpoch(state state.ReadOnlyBeaconState) types.Epoch {
-	currentEpoch := CurrentEpoch(state)
-	if currentEpoch == 0 {
-		return 0
-	}
-	return currentEpoch - 1
-}
-
-// NextEpoch returns the next epoch number calculated from
-// the slot number stored in beacon state.
-func NextEpoch(state state.ReadOnlyBeaconState) types.Epoch {
-	return SlotToEpoch(state.Slot()) + 1
-}
-
-// AltairCompatible returns if the input state `s` is altair compatible and input epoch `e` is higher equal than fork epoch.
-func AltairCompatible(s state.BeaconState, e types.Epoch) bool {
-	return s.Version() == version.Altair && e >= params.BeaconConfig().AltairForkEpoch
-}
-
-// StartSlot returns the first slot number of the
-// current epoch.
-//
-// Spec pseudocode definition:
-//  def compute_start_slot_at_epoch(epoch: Epoch) -> Slot:
-//    """
-//    Return the start slot of ``epoch``.
-//    """
-//    return Slot(epoch * SLOTS_PER_EPOCH)
-func StartSlot(epoch types.Epoch) (types.Slot, error) {
-	slot, err := params.BeaconConfig().SlotsPerEpoch.SafeMul(uint64(epoch))
-	if err != nil {
-		return slot, errors.Errorf("start slot calculation overflows: %v", err)
-	}
-	return slot, nil
-}
-
-// EndSlot returns the last slot number of the
-// current epoch.
-func EndSlot(epoch types.Epoch) (types.Slot, error) {
-	if epoch == math.MaxUint64 {
-		return 0, errors.New("start slot calculation overflows")
-	}
-	slot, err := StartSlot(epoch + 1)
-	if err != nil {
-		return 0, err
-	}
-	return slot - 1, nil
-}
-
-// IsEpochStart returns true if the given slot number is an epoch starting slot
-// number.
-func IsEpochStart(slot types.Slot) bool {
-	return slot%params.BeaconConfig().SlotsPerEpoch == 0
-}
-
-// IsEpochEnd returns true if the given slot number is an epoch ending slot
-// number.
-func IsEpochEnd(slot types.Slot) bool {
-	return IsEpochStart(slot + 1)
-}
-
-// SlotsSinceEpochStarts returns number of slots since the start of the epoch.
-func SlotsSinceEpochStarts(slot types.Slot) types.Slot {
-	return slot % params.BeaconConfig().SlotsPerEpoch
-}
-
-// VerifySlotTime validates the input slot is not from the future.
-func VerifySlotTime(genesisTime uint64, slot types.Slot, timeTolerance time.Duration) error {
-	slotTime, err := SlotToTime(genesisTime, slot)
-	if err != nil {
-		return err
-	}
-
-	// Defensive check to ensure unreasonable slots are rejected
-	// straight away.
-	if err := ValidateSlotClock(slot, genesisTime); err != nil {
-		return err
-	}
-
-	currentTime := prysmTime.Now()
-	diff := slotTime.Sub(currentTime)
-
-	if diff > timeTolerance {
-		return fmt.Errorf("could not process slot from the future, slot time %s > current time %s", slotTime, currentTime)
-	}
-	return nil
-}
-
-// SlotToTime takes the given slot and genesis time to determine the start time of the slot.
-func SlotToTime(genesisTimeSec uint64, slot types.Slot) (time.Time, error) {
-	timeSinceGenesis, err := slot.SafeMul(params.BeaconConfig().SecondsPerSlot)
-	if err != nil {
-		return time.Unix(0, 0), fmt.Errorf("slot (%d) is in the far distant future: %w", slot, err)
-	}
-	sTime, err := timeSinceGenesis.SafeAdd(genesisTimeSec)
-	if err != nil {
-		return time.Unix(0, 0), fmt.Errorf("slot (%d) is in the far distant future: %w", slot, err)
-	}
-	return time.Unix(int64(sTime), 0), nil
-}
-
-// SlotsSince computes the number of time slots that have occurred since the given timestamp.
-func SlotsSince(time time.Time) types.Slot {
-	return CurrentSlot(uint64(time.Unix()))
-}
-
-// CurrentSlot returns the current slot as determined by the local clock and
-// provided genesis time.
-func CurrentSlot(genesisTimeSec uint64) types.Slot {
-	now := prysmTime.Now().Unix()
-	genesis := int64(genesisTimeSec)
-	if now < genesis {
-		return 0
-	}
-	return types.Slot(uint64(now-genesis) / params.BeaconConfig().SecondsPerSlot)
-}
-
-// ValidateSlotClock validates a provided slot against the local
-// clock to ensure slots that are unreasonable are returned with
-// an error.
-func ValidateSlotClock(slot types.Slot, genesisTimeSec uint64) error {
-	maxPossibleSlot := CurrentSlot(genesisTimeSec).Add(MaxSlotBuffer)
-	// Defensive check to ensure that we only process slots up to a hard limit
-	// from our local clock.
-	if slot > maxPossibleSlot {
-		return fmt.Errorf("slot %d > %d which exceeds max allowed value relative to the local clock", slot, maxPossibleSlot)
-	}
-	return nil
-}
-
-// RoundUpToNearestEpoch rounds up the provided slot value to the nearest epoch.
-func RoundUpToNearestEpoch(slot types.Slot) types.Slot {
-	if slot%params.BeaconConfig().SlotsPerEpoch != 0 {
-		slot -= slot % params.BeaconConfig().SlotsPerEpoch
-		slot += params.BeaconConfig().SlotsPerEpoch
-	}
-	return slot
-}
-
-// VotingPeriodStartTime returns the current voting period's start time
-// depending on the provided genesis and current slot.
-func VotingPeriodStartTime(genesis uint64, slot types.Slot) uint64 {
-	slots := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(params.BeaconConfig().EpochsPerEth1VotingPeriod))
-	startTime := uint64((slot - slot.ModSlot(slots)).Mul(params.BeaconConfig().SecondsPerSlot))
-	return genesis + startTime
-}
-
-// PrevSlot returns previous slot, with an exception in slot 0 to prevent underflow.
-func PrevSlot(slot types.Slot) types.Slot {
-	if slot > 0 {
-		return slot.Sub(1)
-	}
-	return 0
-}
-
-// SyncCommitteePeriod returns the sync committee period of input epoch `e`.
-//
-// Spec code:
-// def compute_sync_committee_period(epoch: Epoch) -> uint64:
-//    return epoch // EPOCHS_PER_SYNC_COMMITTEE_PERIOD
-func SyncCommitteePeriod(e types.Epoch) uint64 {
-	return uint64(e / params.BeaconConfig().EpochsPerSyncCommitteePeriod)
-}
-
-// SyncCommitteePeriodStartEpoch returns the start epoch of a sync committee period.
-func SyncCommitteePeriodStartEpoch(e types.Epoch) (types.Epoch, error) {
-	// Overflow is impossible here because of division of `EPOCHS_PER_SYNC_COMMITTEE_PERIOD`.
-	startEpoch, overflow := math2.SafeMul(SyncCommitteePeriod(e), uint64(params.BeaconConfig().EpochsPerSyncCommitteePeriod))
-	if overflow {
-		return 0, errors.New("start epoch calculation overflow")
-	}
-	return types.Epoch(startEpoch), nil
-}
-
-// CanUpgradeToAltair returns true if the input `slot` can upgrade to Altair.
-// Spec code:
-// If state.slot % SLOTS_PER_EPOCH == 0 and compute_epoch_at_slot(state.slot) == ALTAIR_FORK_EPOCH
-func CanUpgradeToAltair(slot types.Slot) bool {
-	epochStart := IsEpochStart(slot)
-	altairEpoch := SlotToEpoch(slot) == params.BeaconConfig().AltairForkEpoch
-	return epochStart && altairEpoch
-}

beacon-chain/core/time/BUILD.bazel

@@ -3,33 +3,13 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = ["slot_epoch.go"],
-    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/core",
-    visibility = [
-        "//beacon-chain:__subpackages__",
-        "//contracts/deposit:__pkg__",
-        "//fuzz:__pkg__",
-        "//network/forks:__pkg__",
-        "//proto/prysm/v1alpha1/attestation:__pkg__",
-        "//runtime/interop:__pkg__",
-        "//shared/attestationutil:__pkg__",
-        "//shared/keystore:__pkg__",
-        "//slasher:__subpackages__",
-        "//testing/altair:__pkg__",
-        "//testing/benchmark/benchmark_files:__subpackages__",
-        "//testing/endtoend/evaluators:__pkg__",
-        "//testing/fuzz:__pkg__",
-        "//testing/spectest:__subpackages__",
-        "//testing/util:__pkg__",
-        "//tools:__subpackages__",
-        "//validator:__subpackages__",
-    ],
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/core/time",
+    visibility = ["//visibility:public"],
     deps = [
         "//beacon-chain/state:go_default_library",
         "//config/params:go_default_library",
         "//runtime/version:go_default_library",
-        "//time:go_default_library",
-        "@com_github_ethereum_go_ethereum//common/math:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
     ],
 )
@@ -45,6 +25,7 @@ go_test(
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//time:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
     ],
 )

beacon-chain/core/time/slot_epoch.go

@@ -0,0 +1,61 @@
+package time
+
+import (
+	types "github.com/prysmaticlabs/eth2-types"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/runtime/version"
+	"github.com/prysmaticlabs/prysm/time/slots"
+)
+
+// CurrentEpoch returns the current epoch number calculated from
+// the slot number stored in beacon state.
+//
+// Spec pseudocode definition:
+//  def get_current_epoch(state: BeaconState) -> Epoch:
+//    """
+//    Return the current epoch.
+//    """
+//    return compute_epoch_at_slot(state.slot)
+func CurrentEpoch(state state.ReadOnlyBeaconState) types.Epoch {
+	return slots.ToEpoch(state.Slot())
+}
+
+// PrevEpoch returns the previous epoch number calculated from
+// the slot number stored in beacon state. It also checks for
+// underflow condition.
+//
+// Spec pseudocode definition:
+//  def get_previous_epoch(state: BeaconState) -> Epoch:
+//    """`
+//    Return the previous epoch (unless the current epoch is ``GENESIS_EPOCH``).
+//    """
+//    current_epoch = get_current_epoch(state)
+//    return GENESIS_EPOCH if current_epoch == GENESIS_EPOCH else Epoch(current_epoch - 1)
+func PrevEpoch(state state.ReadOnlyBeaconState) types.Epoch {
+	currentEpoch := CurrentEpoch(state)
+	if currentEpoch == 0 {
+		return 0
+	}
+	return currentEpoch - 1
+}
+
+// NextEpoch returns the next epoch number calculated from
+// the slot number stored in beacon state.
+func NextEpoch(state state.ReadOnlyBeaconState) types.Epoch {
+	return slots.ToEpoch(state.Slot()) + 1
+}
+
+// AltairCompatible returns if the input state `s` is altair compatible and input epoch `e` is higher equal than fork epoch.
+func AltairCompatible(s state.BeaconState, e types.Epoch) bool {
+	return s.Version() == version.Altair && e >= params.BeaconConfig().AltairForkEpoch
+}
+
+// CanUpgradeToAltair returns true if the input `slot` can upgrade to Altair.
+// Spec code:
+// If state.slot % SLOTS_PER_EPOCH == 0 and compute_epoch_at_slot(state.slot) == ALTAIR_FORK_EPOCH
+func CanUpgradeToAltair(slot types.Slot) bool {
+	epochStart := slots.IsEpochStart(slot)
+	altairEpoch := slots.ToEpoch(slot) == params.BeaconConfig().AltairForkEpoch
+	return epochStart && altairEpoch
+}

beacon-chain/core/time/slot_epoch_test.go

@@ -1,4 +1,4 @@
-package core
+package time
 
 import (
 	"math"
@@ -12,6 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
 	prysmTime "github.com/prysmaticlabs/prysm/time"
+	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
 func TestSlotToEpoch_OK(t *testing.T) {
@@ -26,7 +27,7 @@ func TestSlotToEpoch_OK(t *testing.T) {
 		{slot: 200, epoch: 6},
 	}
 	for _, tt := range tests {
-		assert.Equal(t, tt.epoch, SlotToEpoch(tt.slot), "SlotToEpoch(%d)", tt.slot)
+		assert.Equal(t, tt.epoch, slots.ToEpoch(tt.slot), "ToEpoch(%d)", tt.slot)
 	}
 }
 
@@ -96,10 +97,10 @@ func TestEpochStartSlot_OK(t *testing.T) {
 		{epoch: 1 << 60, startSlot: 1 << 63, error: true},
 	}
 	for _, tt := range tests {
-		ss, err := StartSlot(tt.epoch)
+		ss, err := slots.EpochStart(tt.epoch)
 		if !tt.error {
 			require.NoError(t, err)
-			assert.Equal(t, tt.startSlot, ss, "StartSlot(%d)", tt.epoch)
+			assert.Equal(t, tt.startSlot, ss, "EpochStart(%d)", tt.epoch)
 		} else {
 			require.ErrorContains(t, "start slot calculation overflow", err)
 		}
@@ -120,10 +121,10 @@ func TestEpochEndSlot_OK(t *testing.T) {
 		{epoch: math.MaxUint64, startSlot: 0, error: true},
 	}
 	for _, tt := range tests {
-		ss, err := EndSlot(tt.epoch)
+		ss, err := slots.EpochEnd(tt.epoch)
 		if !tt.error {
 			require.NoError(t, err)
-			assert.Equal(t, tt.startSlot, ss, "StartSlot(%d)", tt.epoch)
+			assert.Equal(t, tt.startSlot, ss, "EpochStart(%d)", tt.epoch)
 		} else {
 			require.ErrorContains(t, "start slot calculation overflow", err)
 		}
@@ -156,7 +157,7 @@ func TestIsEpochStart(t *testing.T) {
 	}
 
 	for _, tt := range tests {
-		assert.Equal(t, tt.result, IsEpochStart(tt.slot), "IsEpochStart(%d)", tt.slot)
+		assert.Equal(t, tt.result, slots.IsEpochStart(tt.slot), "IsEpochStart(%d)", tt.slot)
 	}
 }
 
@@ -182,7 +183,7 @@ func TestIsEpochEnd(t *testing.T) {
 	}
 
 	for _, tt := range tests {
-		assert.Equal(t, tt.result, IsEpochEnd(tt.slot), "IsEpochEnd(%d)", tt.slot)
+		assert.Equal(t, tt.result, slots.IsEpochEnd(tt.slot), "IsEpochEnd(%d)", tt.slot)
 	}
 }
 
@@ -198,7 +199,7 @@ func TestSlotsSinceEpochStarts(t *testing.T) {
 		{slots: 10*params.BeaconConfig().SlotsPerEpoch + 2, wantedSlots: 2},
 	}
 	for _, tt := range tests {
-		assert.Equal(t, tt.wantedSlots, SlotsSinceEpochStarts(tt.slots))
+		assert.Equal(t, tt.wantedSlots, slots.SinceEpochStarts(tt.slots))
 	}
 }
 
@@ -212,7 +213,7 @@ func TestRoundUpToNearestEpoch_OK(t *testing.T) {
 		{startSlot: 10*params.BeaconConfig().SlotsPerEpoch - (params.BeaconConfig().SlotsPerEpoch - 1), roundedUpSlot: 10 * params.BeaconConfig().SlotsPerEpoch},
 	}
 	for _, tt := range tests {
-		assert.Equal(t, tt.roundedUpSlot, RoundUpToNearestEpoch(tt.startSlot), "RoundUpToNearestEpoch(%d)", tt.startSlot)
+		assert.Equal(t, tt.roundedUpSlot, slots.RoundUpToNearestEpoch(tt.startSlot), "RoundUpToNearestEpoch(%d)", tt.startSlot)
 	}
 }
 
@@ -262,7 +263,7 @@ func TestSlotToTime(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := SlotToTime(tt.args.genesisTimeSec, tt.args.slot)
+			got, err := slots.ToTime(tt.args.genesisTimeSec, tt.args.slot)
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 			} else {
@@ -310,7 +311,7 @@ func TestVerifySlotTime(t *testing.T) {
 			name: "max future slot",
 			args: args{
 				genesisTime: prysmTime.Now().Add(-1 * 5 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second).Unix(),
-				slot:        types.Slot(MaxSlotBuffer + 6),
+				slot:        types.Slot(slots.MaxSlotBuffer + 6),
 			},
 			wantedErr: "exceeds max allowed value relative to the local clock",
 		},
@@ -327,7 +328,7 @@ func TestVerifySlotTime(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			err := VerifySlotTime(uint64(tt.args.genesisTime), tt.args.slot, tt.args.timeTolerance)
+			err := slots.VerifyTime(uint64(tt.args.genesisTime), tt.args.slot, tt.args.timeTolerance)
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 			} else {
@@ -338,12 +339,12 @@ func TestVerifySlotTime(t *testing.T) {
 }
 
 func TestValidateSlotClock_HandlesBadSlot(t *testing.T) {
-	genTime := prysmTime.Now().Add(-1 * time.Duration(MaxSlotBuffer) * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second).Unix()
+	genTime := prysmTime.Now().Add(-1 * time.Duration(slots.MaxSlotBuffer) * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second).Unix()
 
-	assert.NoError(t, ValidateSlotClock(types.Slot(MaxSlotBuffer), uint64(genTime)), "unexpected error validating slot")
-	assert.NoError(t, ValidateSlotClock(types.Slot(2*MaxSlotBuffer), uint64(genTime)), "unexpected error validating slot")
-	assert.ErrorContains(t, "which exceeds max allowed value relative to the local clock", ValidateSlotClock(types.Slot(2*MaxSlotBuffer+1), uint64(genTime)), "no error from bad slot")
-	assert.ErrorContains(t, "which exceeds max allowed value relative to the local clock", ValidateSlotClock(1<<63, uint64(genTime)), "no error from bad slot")
+	assert.NoError(t, slots.ValidateClock(types.Slot(slots.MaxSlotBuffer), uint64(genTime)), "unexpected error validating slot")
+	assert.NoError(t, slots.ValidateClock(types.Slot(2*slots.MaxSlotBuffer), uint64(genTime)), "unexpected error validating slot")
+	assert.ErrorContains(t, "which exceeds max allowed value relative to the local clock", slots.ValidateClock(types.Slot(2*slots.MaxSlotBuffer+1), uint64(genTime)), "no error from bad slot")
+	assert.ErrorContains(t, "which exceeds max allowed value relative to the local clock", slots.ValidateClock(1<<63, uint64(genTime)), "no error from bad slot")
 }
 
 func TestPrevSlot(t *testing.T) {
@@ -375,7 +376,7 @@ func TestPrevSlot(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := PrevSlot(tt.slot); got != tt.want {
+			if got := slots.PrevSlot(tt.slot); got != tt.want {
 				t.Errorf("PrevSlot() = %v, want %v", got, tt.want)
 			}
 		})
@@ -393,7 +394,7 @@ func TestSyncCommitteePeriod(t *testing.T) {
 		{epoch: 1000, wanted: 1000 / uint64(params.BeaconConfig().EpochsPerSyncCommitteePeriod)},
 	}
 	for _, test := range tests {
-		require.Equal(t, test.wanted, SyncCommitteePeriod(test.epoch))
+		require.Equal(t, test.wanted, slots.SyncCommitteePeriod(test.epoch))
 	}
 }
 
@@ -408,7 +409,7 @@ func TestSyncCommitteePeriodStartEpoch(t *testing.T) {
 		{epoch: params.BeaconConfig().EpochsPerSyncCommitteePeriod*params.BeaconConfig().EpochsPerSyncCommitteePeriod + 1, wanted: params.BeaconConfig().EpochsPerSyncCommitteePeriod * params.BeaconConfig().EpochsPerSyncCommitteePeriod},
 	}
 	for _, test := range tests {
-		e, err := SyncCommitteePeriodStartEpoch(test.epoch)
+		e, err := slots.SyncCommitteePeriodStartEpoch(test.epoch)
 		require.NoError(t, err)
 		require.Equal(t, test.wanted, e)
 	}

beacon-chain/core/transition/BUILD.bazel

@@ -26,12 +26,12 @@ go_library(
     ],
     deps = [
         "//beacon-chain/cache:go_default_library",
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/blocks:go_default_library",
         "//beacon-chain/core/epoch:go_default_library",
         "//beacon-chain/core/epoch/precompute:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition/interop:go_default_library",
         "//beacon-chain/core/validators:go_default_library",
         "//beacon-chain/state:go_default_library",
@@ -46,6 +46,7 @@ go_library(
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/block:go_default_library",
         "//runtime/version:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
@@ -75,10 +76,11 @@ go_test(
     embed = [":go_default_library"],
     shard_count = 3,
     deps = [
-        "//beacon-chain/core:go_default_library",
         "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/blocks:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/p2p/types:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/v1:go_default_library",