Update ropsten TTD (#10817)

Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

.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

.github/workflows/go.yml

@@ -89,10 +89,10 @@ jobs:
         # Use blst tag to allow go and bazel builds for blst.
         run: go build -v ./...
 
-        # fuzz and blst_disabled leverage go tag based stubs at compile time.
-        # Building with these tags should be checked and enforced at pre-submit.
-      - name: Build for fuzzing
-        run: go build -tags=fuzz,blst_disabled ./... 
+        # fuzz leverage go tag based stubs at compile time.
+        # Building and testing with these tags should be checked and enforced at pre-submit.
+      - name: Test for fuzzing
+        run: go test  -tags=fuzz,develop ./...  -test.run=^Fuzz
 
 # Tests run via Bazel for now...
 #      - name: Test

WORKSPACE

@@ -215,7 +215,7 @@ filegroup(
     url = "https://github.com/eth-clients/slashing-protection-interchange-tests/archive/b8413ca42dc92308019d0d4db52c87e9e125c4e9.tar.gz",
 )
 
-consensus_spec_version = "v1.1.10"
+consensus_spec_version = "v1.2.0-rc.1"
 
 bls_test_version = "v0.1.1"
 
@@ -231,7 +231,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    sha256 = "28043009cc2f6fc9804e73c8c1fc2cb27062f1591e6884f3015ae1dd7a276883",
+    sha256 = "9c93f87378aaa6d6fe1c67b396eac2aacc9594af2a83f028cb99c95dea5b81df",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )
 
@@ -247,7 +247,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    sha256 = "bc1a283ca068f310f04d70c4f6a8eaa0b8f7e9318073a8bdc2ee233111b4e339",
+    sha256 = "52f2c52415228cee8a4de5a09abff785f439a77dfef8f03e834e4e16857673c1",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )
 
@@ -263,7 +263,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    sha256 = "bbabb482c229ff9d4e2c7b77c992edb452f9d0af7c6d8dd4f922f06a7b101e81",
+    sha256 = "022dcc0d6de7dd27b337a0d1b945077eaf5ee47000700395a693fc25e12f96df",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )
 
@@ -278,7 +278,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    sha256 = "408a5524548ad3fcf387f65ac7ec52781d9ee899499720bb12451b48a15818d4",
+    sha256 = "0a9c110305cbd6ebbe0d942f0f33e6ce22dd484ce4ceed277bf185a091941cde",
     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/client/beacon/checkpoint.go

@@ -26,69 +26,126 @@ type OriginData struct {
 	bb  []byte
 	st  state.BeaconState
 	b   interfaces.SignedBeaconBlock
-	cf  *detect.VersionedUnmarshaler
-}
-
-// CheckpointString returns the standard string representation of a Checkpoint for the block root and epoch for the
-// SignedBeaconBlock value found by DownloadOriginData.
-// The format is a a hex-encoded block root, followed by the epoch of the block, separated by a colon. For example:
-// "0x1c35540cac127315fabb6bf29181f2ae0de1a3fc909d2e76ba771e61312cc49a:74888"
-func (od *OriginData) CheckpointString() string {
-	return fmt.Sprintf("%#x:%d", od.wsd.BlockRoot, od.wsd.Epoch)
+	vu  *detect.VersionedUnmarshaler
+	br  [32]byte
+	sr  [32]byte
 }
 
 // SaveBlock saves the downloaded block to a unique file in the given path.
 // For readability and collision avoidance, the file name includes: type, config name, slot and root
-func (od *OriginData) SaveBlock(dir string) (string, error) {
-	blockPath := path.Join(dir, fname("block", od.cf, od.b.Block().Slot(), od.wsd.BlockRoot))
-	return blockPath, file.WriteFile(blockPath, od.BlockBytes())
+func (o *OriginData) SaveBlock(dir string) (string, error) {
+	blockPath := path.Join(dir, fname("block", o.vu, o.b.Block().Slot(), o.br))
+	return blockPath, file.WriteFile(blockPath, o.BlockBytes())
 }
 
 // SaveState saves the downloaded state to a unique file in the given path.
 // For readability and collision avoidance, the file name includes: type, config name, slot and root
-func (od *OriginData) SaveState(dir string) (string, error) {
-	statePath := path.Join(dir, fname("state", od.cf, od.st.Slot(), od.wsd.StateRoot))
-	return statePath, file.WriteFile(statePath, od.StateBytes())
+func (o *OriginData) SaveState(dir string) (string, error) {
+	statePath := path.Join(dir, fname("state", o.vu, o.st.Slot(), o.sr))
+	return statePath, file.WriteFile(statePath, o.StateBytes())
 }
 
 // StateBytes returns the ssz-encoded bytes of the downloaded BeaconState value.
-func (od *OriginData) StateBytes() []byte {
-	return od.sb
+func (o *OriginData) StateBytes() []byte {
+	return o.sb
 }
 
 // BlockBytes returns the ssz-encoded bytes of the downloaded SignedBeaconBlock value.
-func (od *OriginData) BlockBytes() []byte {
-	return od.bb
+func (o *OriginData) BlockBytes() []byte {
+	return o.bb
 }
 
-func fname(prefix string, cf *detect.VersionedUnmarshaler, slot types.Slot, root [32]byte) string {
-	return fmt.Sprintf("%s_%s_%s_%d-%#x.ssz", prefix, cf.Config.ConfigName, version.String(cf.Fork), slot, root)
+func fname(prefix string, vu *detect.VersionedUnmarshaler, slot types.Slot, root [32]byte) string {
+	return fmt.Sprintf("%s_%s_%s_%d-%#x.ssz", prefix, vu.Config.ConfigName, version.String(vu.Fork), slot, root)
 }
 
-// this method downloads the head state, which can be used to find the correct chain config
-// and use prysm's helper methods to compute the latest weak subjectivity epoch.
-func getWeakSubjectivityEpochFromHead(ctx context.Context, client *Client) (types.Epoch, error) {
-	headBytes, err := client.GetState(ctx, IdHead)
+// DownloadFinalizedData downloads the most recently finalized state, and the block most recently applied to that state.
+// This pair can be used to initialize a new beacon node via checkpoint sync.
+func DownloadFinalizedData(ctx context.Context, client *Client) (*OriginData, error) {
+	sb, err := client.GetState(ctx, IdFinalized)
 	if err != nil {
-		return 0, err
+		return nil, err
 	}
-	cf, err := detect.FromState(headBytes)
+	vu, err := detect.FromState(sb)
 	if err != nil {
-		return 0, errors.Wrap(err, "error detecting chain config for beacon state")
+		return nil, errors.Wrap(err, "error detecting chain config for finalized state")
 	}
-	log.Printf("detected supported config in remote head state, name=%s, fork=%s", cf.Config.ConfigName, version.String(cf.Fork))
-	headState, err := cf.UnmarshalBeaconState(headBytes)
+	log.Printf("detected supported config in remote finalized state, name=%s, fork=%s", vu.Config.ConfigName, version.String(vu.Fork))
+	s, err := vu.UnmarshalBeaconState(sb)
 	if err != nil {
-		return 0, errors.Wrap(err, "error unmarshaling state to correct version")
+		return nil, errors.Wrap(err, "error unmarshaling finalized state to correct version")
 	}
 
-	epoch, err := helpers.LatestWeakSubjectivityEpoch(ctx, headState, cf.Config)
+	sr, err := s.HashTreeRoot(ctx)
 	if err != nil {
-		return 0, errors.Wrap(err, "error computing the weak subjectivity epoch from head state")
+		return nil, errors.Wrapf(err, "failed to compute htr for finalized state at slot=%d", s.Slot())
+	}
+	header := s.LatestBlockHeader()
+	header.StateRoot = sr[:]
+	br, err := header.HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "error while computing block root using state data")
 	}
 
-	log.Printf("(computed client-side) weak subjectivity epoch = %d", epoch)
-	return epoch, nil
+	bb, err := client.GetBlock(ctx, IdFromRoot(br))
+	if err != nil {
+		return nil, errors.Wrapf(err, "error requesting block by root = %#x", br)
+	}
+	b, err := vu.UnmarshalBeaconBlock(bb)
+	if err != nil {
+		return nil, errors.Wrap(err, "unable to unmarshal block to a supported type using the detected fork schedule")
+	}
+	realBlockRoot, err := b.Block().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "error computing hash_tree_root of retrieved block")
+	}
+
+	log.Printf("BeaconState slot=%d, Block slot=%d", s.Slot(), b.Block().Slot())
+	log.Printf("BeaconState htr=%#xd, Block state_root=%#x", sr, b.Block().StateRoot())
+	log.Printf("BeaconState latest_block_header htr=%#xd, block htr=%#x", br, realBlockRoot)
+	return &OriginData{
+		st: s,
+		b:  b,
+		sb: sb,
+		bb: bb,
+		vu: vu,
+		br: br,
+		sr: sr,
+	}, nil
+}
+
+// WeakSubjectivityData represents the state root, block root and epoch of the BeaconState + SignedBeaconBlock
+// that falls at the beginning of the current weak subjectivity period. These values can be used to construct
+// a weak subjectivity checkpoint beacon node flag to be used for validation.
+type WeakSubjectivityData struct {
+	BlockRoot [32]byte
+	StateRoot [32]byte
+	Epoch     types.Epoch
+}
+
+// CheckpointString returns the standard string representation of a Checkpoint.
+// The format is a a hex-encoded block root, followed by the epoch of the block, separated by a colon. For example:
+// "0x1c35540cac127315fabb6bf29181f2ae0de1a3fc909d2e76ba771e61312cc49a:74888"
+func (wsd *WeakSubjectivityData) CheckpointString() string {
+	return fmt.Sprintf("%#x:%d", wsd.BlockRoot, wsd.Epoch)
+}
+
+// ComputeWeakSubjectivityCheckpoint attempts to use the prysm weak_subjectivity api
+// to obtain the current weak_subjectivity checkpoint.
+// For non-prysm nodes, the same computation will be performed with extra steps,
+// using the head state downloaded from the beacon node api.
+func ComputeWeakSubjectivityCheckpoint(ctx context.Context, client *Client) (*WeakSubjectivityData, error) {
+	ws, err := client.GetWeakSubjectivity(ctx)
+	if err != nil {
+		// a 404/405 is expected if querying an endpoint that doesn't support the weak subjectivity checkpoint api
+		if !errors.Is(err, ErrNotOK) {
+			return nil, errors.Wrap(err, "unexpected API response for prysm-only weak subjectivity checkpoint API")
+		}
+		// fall back to vanilla Beacon Node API method
+		return computeBackwardsCompatible(ctx, client)
+	}
+	log.Printf("server weak subjectivity checkpoint response - epoch=%d, block_root=%#x, state_root=%#x", ws.Epoch, ws.BlockRoot, ws.StateRoot)
+	return ws, nil
 }
 
 const (
@@ -96,8 +153,8 @@ const (
 	prysmImplementationName = "Prysm"
 )
 
-// ErrUnsupportedPrysmCheckpointVersion indicates remote beacon node can't be used for checkpoint retrieval.
-var ErrUnsupportedPrysmCheckpointVersion = errors.New("node does not meet minimum version requirements for checkpoint retrieval")
+// errUnsupportedPrysmCheckpointVersion indicates remote beacon node can't be used for checkpoint retrieval.
+var errUnsupportedPrysmCheckpointVersion = errors.New("node does not meet minimum version requirements for checkpoint retrieval")
 
 // for older endpoints or clients that do not support the weak_subjectivity api method
 // we gather the necessary data for a checkpoint sync by:
@@ -105,14 +162,14 @@ var ErrUnsupportedPrysmCheckpointVersion = errors.New("node does not meet minimu
 // - requesting the state at the first slot of the epoch
 // - using hash_tree_root(state.latest_block_header) to compute the block the state integrates
 // - requesting that block by its root
-func downloadBackwardsCompatible(ctx context.Context, client *Client) (*OriginData, error) {
+func computeBackwardsCompatible(ctx context.Context, client *Client) (*WeakSubjectivityData, error) {
 	log.Print("falling back to generic checkpoint derivation, weak_subjectivity API not supported by server")
 	nv, err := client.GetNodeVersion(ctx)
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to proceed with fallback method without confirming node version")
 	}
 	if nv.implementation == prysmImplementationName && semver.Compare(nv.semver, prysmMinimumVersion) < 0 {
-		return nil, errors.Wrapf(ErrUnsupportedPrysmCheckpointVersion, "%s < minimum (%s)", nv.semver, prysmMinimumVersion)
+		return nil, errors.Wrapf(errUnsupportedPrysmCheckpointVersion, "%s < minimum (%s)", nv.semver, prysmMinimumVersion)
 	}
 	epoch, err := getWeakSubjectivityEpochFromHead(ctx, client)
 	if err != nil {
@@ -127,136 +184,78 @@ func downloadBackwardsCompatible(ctx context.Context, client *Client) (*OriginDa
 
 	log.Printf("requesting checkpoint state at slot %d", slot)
 	// get the state at the first slot of the epoch
-	stateBytes, err := client.GetState(ctx, IdFromSlot(slot))
+	sb, err := client.GetState(ctx, IdFromSlot(slot))
 	if err != nil {
 		return nil, errors.Wrapf(err, "failed to request state by slot from api, slot=%d", slot)
 	}
 
 	// ConfigFork is used to unmarshal the BeaconState so we can read the block root in latest_block_header
-	cf, err := detect.FromState(stateBytes)
+	vu, err := detect.FromState(sb)
 	if err != nil {
 		return nil, errors.Wrap(err, "error detecting chain config for beacon state")
 	}
-	log.Printf("detected supported config in checkpoint state, name=%s, fork=%s", cf.Config.ConfigName, version.String(cf.Fork))
+	log.Printf("detected supported config in checkpoint state, name=%s, fork=%s", vu.Config.ConfigName, version.String(vu.Fork))
 
-	st, err := cf.UnmarshalBeaconState(stateBytes)
+	s, err := vu.UnmarshalBeaconState(sb)
 	if err != nil {
 		return nil, errors.Wrap(err, "error using detected config fork to unmarshal state bytes")
 	}
 
 	// compute state and block roots
-	stateRoot, err := st.HashTreeRoot(ctx)
+	sr, err := s.HashTreeRoot(ctx)
 	if err != nil {
 		return nil, errors.Wrap(err, "error computing hash_tree_root of state")
 	}
 
-	header := st.LatestBlockHeader()
-	header.StateRoot = stateRoot[:]
-	computedBlockRoot, err := header.HashTreeRoot()
+	h := s.LatestBlockHeader()
+	h.StateRoot = sr[:]
+	br, err := h.HashTreeRoot()
 	if err != nil {
 		return nil, errors.Wrap(err, "error while computing block root using state data")
 	}
 
-	blockBytes, err := client.GetBlock(ctx, IdFromRoot(computedBlockRoot))
+	bb, err := client.GetBlock(ctx, IdFromRoot(br))
 	if err != nil {
-		return nil, errors.Wrapf(err, "error requesting block by root = %d", computedBlockRoot)
+		return nil, errors.Wrapf(err, "error requesting block by root = %d", br)
 	}
-	block, err := cf.UnmarshalBeaconBlock(blockBytes)
+	b, err := vu.UnmarshalBeaconBlock(bb)
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to unmarshal block to a supported type using the detected fork schedule")
 	}
-	blockRoot, err := block.Block().HashTreeRoot()
+	br, err = b.Block().HashTreeRoot()
 	if err != nil {
 		return nil, errors.Wrap(err, "error computing hash_tree_root for block obtained via root")
 	}
 
-	log.Printf("BeaconState slot=%d, Block slot=%d", st.Slot(), block.Block().Slot())
-	log.Printf("BeaconState htr=%#xd, Block state_root=%#x", stateRoot, block.Block().StateRoot())
-	log.Printf("BeaconBlock root computed from state=%#x, Block htr=%#x", computedBlockRoot, blockRoot)
-
-	return &OriginData{
-		wsd: &WeakSubjectivityData{
-			BlockRoot: blockRoot,
-			StateRoot: stateRoot,
-			Epoch:     epoch,
-		},
-		st: st,
-		sb: stateBytes,
-		b:  block,
-		bb: blockBytes,
-		cf: cf,
+	return &WeakSubjectivityData{
+		Epoch:     epoch,
+		BlockRoot: br,
+		StateRoot: sr,
 	}, nil
 }
 
-// DownloadOriginData attempts to use the proposed weak_subjectivity beacon node api
-// to obtain the weak_subjectivity metadata (epoch, block_root, state_root) needed to sync
-// a beacon node from the canonical weak subjectivity checkpoint. As this is a proposed API
-// that will only be supported by prysm at first, in the event of a 404 we fallback to using a
-// different technique where we first download the head state which can be used to compute the
-// weak subjectivity epoch on the client side.
-func DownloadOriginData(ctx context.Context, client *Client) (*OriginData, error) {
-	ws, err := client.GetWeakSubjectivity(ctx)
+// this method downloads the head state, which can be used to find the correct chain config
+// and use prysm's helper methods to compute the latest weak subjectivity epoch.
+func getWeakSubjectivityEpochFromHead(ctx context.Context, client *Client) (types.Epoch, error) {
+	headBytes, err := client.GetState(ctx, IdHead)
 	if err != nil {
-		// a 404/405 is expected if querying an endpoint that doesn't support the weak subjectivity checkpoint api
-		if !errors.Is(err, ErrNotOK) {
-			return nil, errors.Wrap(err, "unexpected API response for prysm-only weak subjectivity checkpoint API")
-		}
-		// fall back to vanilla Beacon Node API method
-		return downloadBackwardsCompatible(ctx, client)
+		return 0, err
 	}
-	log.Printf("server weak subjectivity checkpoint response - epoch=%d, block_root=%#x, state_root=%#x", ws.Epoch, ws.BlockRoot, ws.StateRoot)
-
-	// use first slot of the epoch for the block slot
-	slot, err := slots.EpochStart(ws.Epoch)
+	vu, err := detect.FromState(headBytes)
 	if err != nil {
-		return nil, errors.Wrapf(err, "error computing first slot of epoch=%d", ws.Epoch)
+		return 0, errors.Wrap(err, "error detecting chain config for beacon state")
 	}
-	log.Printf("requesting checkpoint state at slot %d", slot)
-
-	stateBytes, err := client.GetState(ctx, IdFromSlot(slot))
+	log.Printf("detected supported config in remote head state, name=%s, fork=%s", vu.Config.ConfigName, version.String(vu.Fork))
+	headState, err := vu.UnmarshalBeaconState(headBytes)
 	if err != nil {
-		return nil, errors.Wrapf(err, "failed to request state by slot from api, slot=%d", slot)
-	}
-	cf, err := detect.FromState(stateBytes)
-	if err != nil {
-		return nil, errors.Wrap(err, "error detecting chain config for beacon state")
-	}
-	log.Printf("detected supported config in checkpoint state, name=%s, fork=%s", cf.Config.ConfigName, version.String(cf.Fork))
-
-	state, err := cf.UnmarshalBeaconState(stateBytes)
-	if err != nil {
-		return nil, errors.Wrap(err, "error using detected config fork to unmarshal state bytes")
-	}
-	stateRoot, err := state.HashTreeRoot(ctx)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to compute htr for state at slot=%d", slot)
+		return 0, errors.Wrap(err, "error unmarshaling state to correct version")
 	}
 
-	blockRoot, err := state.LatestBlockHeader().HashTreeRoot()
+	epoch, err := helpers.LatestWeakSubjectivityEpoch(ctx, headState, vu.Config)
 	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root of latest_block_header")
+		return 0, errors.Wrap(err, "error computing the weak subjectivity epoch from head state")
 	}
-	blockBytes, err := client.GetBlock(ctx, IdFromRoot(ws.BlockRoot))
-	if err != nil {
-		return nil, errors.Wrapf(err, "error requesting block by slot = %d", slot)
-	}
-	block, err := cf.UnmarshalBeaconBlock(blockBytes)
-	if err != nil {
-		return nil, errors.Wrap(err, "unable to unmarshal block to a supported type using the detected fork schedule")
-	}
-	realBlockRoot, err := block.Block().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root of retrieved block")
-	}
-	log.Printf("BeaconState slot=%d, Block slot=%d", state.Slot(), block.Block().Slot())
-	log.Printf("BeaconState htr=%#xd, Block state_root=%#x", stateRoot, block.Block().StateRoot())
-	log.Printf("BeaconState latest_block_header htr=%#xd, block htr=%#x", blockRoot, realBlockRoot)
-	return &OriginData{
-		wsd: ws,
-		st:  state,
-		b:   block,
-		sb:  stateBytes,
-		bb:  blockBytes,
-		cf:  cf,
-	}, nil
+
+	log.Printf("(computed client-side) weak subjectivity epoch = %d", epoch)
+	return epoch, nil
 }

api/client/beacon/checkpoint_test.go

@@ -93,8 +93,8 @@ func TestFallbackVersionCheck(t *testing.T) {
 	}}
 
 	ctx := context.Background()
-	_, err := DownloadOriginData(ctx, c)
-	require.ErrorIs(t, err, ErrUnsupportedPrysmCheckpointVersion)
+	_, err := ComputeWeakSubjectivityCheckpoint(ctx, c)
+	require.ErrorIs(t, err, errUnsupportedPrysmCheckpointVersion)
 }
 
 func TestFname(t *testing.T) {
@@ -120,9 +120,9 @@ func TestFname(t *testing.T) {
 	require.Equal(t, expected, actual)
 }
 
-func TestDownloadOriginData(t *testing.T) {
+func TestDownloadWeakSubjectivityCheckpoint(t *testing.T) {
 	ctx := context.Background()
-	cfg := params.MainnetConfig()
+	cfg := params.MainnetConfig().Copy()
 
 	epoch := cfg.AltairForkEpoch - 1
 	// set up checkpoint state, using the epoch that will be computed as the ws checkpoint state based on the head state
@@ -204,19 +204,15 @@ func TestDownloadOriginData(t *testing.T) {
 		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 	}
 
-	od, err := DownloadOriginData(ctx, c)
+	wsd, err := ComputeWeakSubjectivityCheckpoint(ctx, c)
 	require.NoError(t, err)
-	require.Equal(t, expectedWSD.Epoch, od.wsd.Epoch)
-	require.Equal(t, expectedWSD.StateRoot, od.wsd.StateRoot)
-	require.Equal(t, expectedWSD.BlockRoot, od.wsd.BlockRoot)
-	require.DeepEqual(t, wsSerialized, od.sb)
-	require.DeepEqual(t, serBlock, od.bb)
-	require.DeepEqual(t, wst.Fork().CurrentVersion, od.cf.Version[:])
-	require.DeepEqual(t, version.Phase0, od.cf.Fork)
+	require.Equal(t, expectedWSD.Epoch, wsd.Epoch)
+	require.Equal(t, expectedWSD.StateRoot, wsd.StateRoot)
+	require.Equal(t, expectedWSD.BlockRoot, wsd.BlockRoot)
 }
 
-// runs downloadBackwardsCompatible directly
-// and via DownloadOriginData with a round tripper that triggers the backwards compatible code path
+// runs computeBackwardsCompatible directly
+// and via ComputeWeakSubjectivityCheckpoint with a round tripper that triggers the backwards compatible code path
 func TestDownloadBackwardsCompatibleCombined(t *testing.T) {
 	ctx := context.Background()
 	cfg := params.MainnetConfig()
@@ -297,16 +293,12 @@ func TestDownloadBackwardsCompatibleCombined(t *testing.T) {
 		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
 	}
 
-	odPub, err := DownloadOriginData(ctx, c)
+	wsPub, err := ComputeWeakSubjectivityCheckpoint(ctx, c)
 	require.NoError(t, err)
 
-	odPriv, err := downloadBackwardsCompatible(ctx, c)
+	wsPriv, err := computeBackwardsCompatible(ctx, c)
 	require.NoError(t, err)
-	require.DeepEqual(t, odPriv.wsd, odPub.wsd)
-	require.DeepEqual(t, odPriv.sb, odPub.sb)
-	require.DeepEqual(t, odPriv.bb, odPub.bb)
-	require.DeepEqual(t, odPriv.cf.Fork, odPub.cf.Fork)
-	require.DeepEqual(t, odPriv.cf.Version, odPub.cf.Version)
+	require.DeepEqual(t, wsPriv, wsPub)
 }
 
 func TestGetWeakSubjectivityEpochFromHead(t *testing.T) {
@@ -402,3 +394,94 @@ func populateValidators(cfg *params.BeaconChainConfig, st state.BeaconState, val
 
 	return nil
 }
+
+func TestDownloadFinalizedData(t *testing.T) {
+	ctx := context.Background()
+	cfg := params.MainnetConfig().Copy()
+
+	// avoid the altair zone because genesis tests are easier to set up
+	epoch := cfg.AltairForkEpoch - 1
+	// set up checkpoint state, using the epoch that will be computed as the ws checkpoint state based on the head state
+	slot, err := slots.EpochStart(epoch)
+	require.NoError(t, err)
+	st, err := util.NewBeaconState()
+	require.NoError(t, err)
+	fork, err := forkForEpoch(cfg, epoch)
+	require.NoError(t, st.SetFork(fork))
+
+	// set up checkpoint block
+	b, err := wrapper.WrappedSignedBeaconBlock(util.NewBeaconBlock())
+	require.NoError(t, wrapper.SetBlockParentRoot(b, cfg.ZeroHash))
+	require.NoError(t, wrapper.SetBlockSlot(b, slot))
+	require.NoError(t, wrapper.SetProposerIndex(b, 0))
+
+	// set up state header pointing at checkpoint block - this is how the block is downloaded by root
+	header, err := b.Header()
+	require.NoError(t, err)
+	require.NoError(t, st.SetLatestBlockHeader(header.Header))
+
+	// order of operations can be confusing here:
+	// - when computing the state root, make sure block header is complete, EXCEPT the state root should be zero-value
+	// - before computing the block root (to match the request route), the block should include the state root
+	//   *computed from the state with a header that does not have a state root set yet*
+	sr, err := st.HashTreeRoot(ctx)
+	require.NoError(t, err)
+
+	require.NoError(t, wrapper.SetBlockStateRoot(b, sr))
+	mb, err := b.MarshalSSZ()
+	require.NoError(t, err)
+	br, err := b.Block().HashTreeRoot()
+	require.NoError(t, err)
+
+	ms, err := st.MarshalSSZ()
+	require.NoError(t, err)
+
+	hc := &http.Client{
+		Transport: &testRT{rt: func(req *http.Request) (*http.Response, error) {
+			res := &http.Response{Request: req}
+			switch req.URL.Path {
+			case renderGetStatePath(IdFinalized):
+				res.StatusCode = http.StatusOK
+				res.Body = io.NopCloser(bytes.NewBuffer(ms))
+			case renderGetBlockPath(IdFromRoot(br)):
+				res.StatusCode = http.StatusOK
+				res.Body = io.NopCloser(bytes.NewBuffer(mb))
+			default:
+				res.StatusCode = http.StatusInternalServerError
+				res.Body = io.NopCloser(bytes.NewBufferString(""))
+			}
+
+			return res, nil
+		}},
+	}
+	c := &Client{
+		hc:      hc,
+		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+	}
+
+	// sanity check before we go through checkpoint
+	// make sure we can download the state and unmarshal it with the VersionedUnmarshaler
+	sb, err := c.GetState(ctx, IdFinalized)
+	require.NoError(t, err)
+	require.Equal(t, true, bytes.Equal(sb, ms))
+	vu, err := detect.FromState(sb)
+	require.NoError(t, err)
+	us, err := vu.UnmarshalBeaconState(sb)
+	require.NoError(t, err)
+	ushtr, err := us.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	require.Equal(t, sr, ushtr)
+
+	expected := &OriginData{
+		sb: ms,
+		bb: mb,
+		br: br,
+		sr: sr,
+	}
+	od, err := DownloadFinalizedData(ctx, c)
+	require.NoError(t, err)
+	require.Equal(t, true, bytes.Equal(expected.sb, od.sb))
+	require.Equal(t, true, bytes.Equal(expected.bb, od.bb))
+	require.Equal(t, expected.br, od.br)
+	require.Equal(t, expected.sr, od.sr)
+}

api/client/beacon/client.go

@@ -46,8 +46,9 @@ const (
 type StateOrBlockId string
 
 const (
-	IdGenesis StateOrBlockId = "genesis"
-	IdHead    StateOrBlockId = "head"
+	IdGenesis   StateOrBlockId = "genesis"
+	IdHead      StateOrBlockId = "head"
+	IdFinalized StateOrBlockId = "finalized"
 )
 
 var ErrMalformedHostname = errors.New("hostname must include port, separated by one colon, like example.com:3500")
@@ -344,16 +345,6 @@ func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData
 	}, nil
 }
 
-// WeakSubjectivityData represents the state root, block root and epoch of the BeaconState + SignedBeaconBlock
-// that falls at the beginning of the current weak subjectivity period. These values can be used to construct
-// a weak subjectivity checkpoint, or to download a BeaconState+SignedBeaconBlock pair that can be used to bootstrap
-// a new Beacon Node using Checkpoint Sync.
-type WeakSubjectivityData struct {
-	BlockRoot [32]byte
-	StateRoot [32]byte
-	Epoch     types.Epoch
-}
-
 func non200Err(response *http.Response) error {
 	bodyBytes, err := io.ReadAll(response.Body)
 	var body string

api/client/builder/BUILD.bazel

@@ -0,0 +1,41 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "client.go",
+        "errors.go",
+        "types.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/api/client/builder",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//consensus-types/primitives:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "client_test.go",
+        "types_test.go",
+    ],
+    data = glob(["testdata/**"]),
+    embed = [":go_default_library"],
+    deps = [
+        "//config/fieldparams:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/require:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
+    ],
+)

api/client/builder/client.go

@@ -0,0 +1,254 @@
+package builder
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"text/template"
+	"time"
+
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+
+	"github.com/pkg/errors"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	getExecHeaderPath          = "/eth/v1/builder/header/{{.Slot}}/{{.ParentHash}}/{{.Pubkey}}"
+	getStatus                  = "/eth/v1/builder/status"
+	postBlindedBeaconBlockPath = "/eth/v1/builder/blinded_blocks"
+	postRegisterValidatorPath  = "/eth/v1/builder/validators"
+)
+
+var errMalformedHostname = errors.New("hostname must include port, separated by one colon, like example.com:3500")
+
+// ClientOpt is a functional option for the Client type (http.Client wrapper)
+type ClientOpt func(*Client)
+
+// WithTimeout sets the .Timeout attribute of the wrapped http.Client.
+func WithTimeout(timeout time.Duration) ClientOpt {
+	return func(c *Client) {
+		c.hc.Timeout = timeout
+	}
+}
+
+type observer interface {
+	observe(r *http.Request) error
+}
+
+func WithObserver(m observer) ClientOpt {
+	return func(c *Client) {
+		c.obvs = append(c.obvs, m)
+	}
+}
+
+type requestLogger struct{}
+
+func (*requestLogger) observe(r *http.Request) (e error) {
+	b := bytes.NewBuffer(nil)
+	if r.Body == nil {
+		log.WithFields(log.Fields{
+			"body-base64": "(nil value)",
+			"url":         r.URL.String(),
+		}).Info("builder http request")
+		return nil
+	}
+	t := io.TeeReader(r.Body, b)
+	defer func() {
+		if r.Body != nil {
+			e = r.Body.Close()
+		}
+	}()
+	body, err := io.ReadAll(t)
+	if err != nil {
+		return err
+	}
+	r.Body = io.NopCloser(b)
+	log.WithFields(log.Fields{
+		"body-base64": string(body),
+		"url":         r.URL.String(),
+	}).Info("builder http request")
+
+	return nil
+}
+
+var _ observer = &requestLogger{}
+
+// Client provides a collection of helper methods for calling Builder API endpoints.
+type Client struct {
+	hc      *http.Client
+	baseURL *url.URL
+	obvs    []observer
+}
+
+// NewClient constructs a new client with the provided options (ex WithTimeout).
+// `host` is the base host + port used to construct request urls. This value can be
+// a URL string, or NewClient will assume an http endpoint if just `host:port` is used.
+func NewClient(host string, opts ...ClientOpt) (*Client, error) {
+	u, err := urlForHost(host)
+	if err != nil {
+		return nil, err
+	}
+	c := &Client{
+		hc:      &http.Client{},
+		baseURL: u,
+	}
+	for _, o := range opts {
+		o(c)
+	}
+	return c, nil
+}
+
+func urlForHost(h string) (*url.URL, error) {
+	// try to parse as url (being permissive)
+	u, err := url.Parse(h)
+	if err == nil && u.Host != "" {
+		return u, nil
+	}
+	// try to parse as host:port
+	host, port, err := net.SplitHostPort(h)
+	if err != nil {
+		return nil, errMalformedHostname
+	}
+	return &url.URL{Host: net.JoinHostPort(host, port), Scheme: "http"}, nil
+}
+
+// NodeURL returns a human-readable string representation of the beacon node base url.
+func (c *Client) NodeURL() string {
+	return c.baseURL.String()
+}
+
+type reqOption func(*http.Request)
+
+// do is a generic, opinionated GET function to reduce boilerplate amongst the getters in this packageapi/client/builder/types.go.
+func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, opts ...reqOption) ([]byte, error) {
+	u := c.baseURL.ResolveReference(&url.URL{Path: path})
+	log.Printf("requesting %s", u.String())
+	req, err := http.NewRequestWithContext(ctx, method, u.String(), body)
+	if err != nil {
+		return nil, err
+	}
+	for _, o := range opts {
+		o(req)
+	}
+	for _, o := range c.obvs {
+		if err := o.observe(req); err != nil {
+			return nil, err
+		}
+	}
+	r, err := c.hc.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		err = r.Body.Close()
+	}()
+	if r.StatusCode != http.StatusOK {
+		return nil, non200Err(r)
+	}
+	b, err := io.ReadAll(r.Body)
+	if err != nil {
+		return nil, errors.Wrap(err, "error reading http response body from GetBlock")
+	}
+	return b, nil
+}
+
+var execHeaderTemplate = template.Must(template.New("").Parse(getExecHeaderPath))
+
+func execHeaderPath(slot types.Slot, parentHash [32]byte, pubkey [48]byte) (string, error) {
+	v := struct {
+		Slot       types.Slot
+		ParentHash string
+		Pubkey     string
+	}{
+		Slot:       slot,
+		ParentHash: fmt.Sprintf("%#x", parentHash),
+		Pubkey:     fmt.Sprintf("%#x", pubkey),
+	}
+	b := bytes.NewBuffer(nil)
+	err := execHeaderTemplate.Execute(b, v)
+	if err != nil {
+		return "", errors.Wrapf(err, "error rendering exec header template with slot=%d, parentHash=%#x, pubkey=%#x", slot, parentHash, pubkey)
+	}
+	return b.String(), nil
+}
+
+// GetHeader is used by a proposing validator to request an ExecutionPayloadHeader from the Builder node.
+func (c *Client) GetHeader(ctx context.Context, slot types.Slot, parentHash [32]byte, pubkey [48]byte) (*ethpb.SignedBuilderBid, error) {
+	path, err := execHeaderPath(slot, parentHash, pubkey)
+	if err != nil {
+		return nil, err
+	}
+	hb, err := c.do(ctx, http.MethodGet, path, nil)
+	if err != nil {
+		return nil, err
+	}
+	hr := &ExecHeaderResponse{}
+	if err := json.Unmarshal(hb, hr); err != nil {
+		return nil, errors.Wrapf(err, "error unmarshaling the builder GetHeader response, using slot=%d, parentHash=%#x, pubkey=%#x", slot, parentHash, pubkey)
+	}
+	return hr.ToProto()
+}
+
+// RegisterValidator encodes the SignedValidatorRegistrationV1 message to json (including hex-encoding the byte
+// fields with 0x prefixes) and posts to the builder validator registration endpoint.
+func (c *Client) RegisterValidator(ctx context.Context, svr *ethpb.SignedValidatorRegistrationV1) error {
+	v := &SignedValidatorRegistration{SignedValidatorRegistrationV1: svr}
+	body, err := json.Marshal(v)
+	if err != nil {
+		return errors.Wrap(err, "error encoding the SignedValidatorRegistration value body in RegisterValidator")
+	}
+	_, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body))
+	return err
+}
+
+// SubmitBlindedBlock calls the builder API endpoint that binds the validator to the builder and submits the block.
+// The response is the full ExecutionPayload used to create the blinded block.
+func (c *Client) SubmitBlindedBlock(ctx context.Context, sb *ethpb.SignedBlindedBeaconBlockBellatrix) (*v1.ExecutionPayload, error) {
+	v := &SignedBlindedBeaconBlockBellatrix{SignedBlindedBeaconBlockBellatrix: sb}
+	body, err := json.Marshal(v)
+	if err != nil {
+		return nil, errors.Wrap(err, "error encoding the SignedBlindedBeaconBlockBellatrix value body in SubmitBlindedBlock")
+	}
+	rb, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body))
+	if err != nil {
+		return nil, errors.Wrap(err, "error posting the SignedBlindedBeaconBlockBellatrix to the builder api")
+	}
+	ep := &ExecPayloadResponse{}
+	if err := json.Unmarshal(rb, ep); err != nil {
+		return nil, errors.Wrap(err, "error unmarshaling the builder SubmitBlindedBlock response")
+	}
+	return ep.ToProto()
+}
+
+// Status asks the remote builder server for a health check. A response of 200 with an empty body is the success/healthy
+// response, and an error response may have an error message. This method will return a nil value for error in the
+// happy path, and an error with information about the server response body for a non-200 response.
+func (c *Client) Status(ctx context.Context) error {
+	_, err := c.do(ctx, http.MethodGet, getStatus, nil)
+	return err
+}
+
+func non200Err(response *http.Response) error {
+	bodyBytes, err := io.ReadAll(response.Body)
+	var body string
+	if err != nil {
+		body = "(Unable to read response body.)"
+	} else {
+		body = "response body:\n" + string(bodyBytes)
+	}
+	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
+	switch response.StatusCode {
+	case 404:
+		return errors.Wrap(ErrNotFound, msg)
+	default:
+		return errors.Wrap(ErrNotOK, msg)
+	}
+}

api/client/builder/client_test.go

@@ -0,0 +1,344 @@
+package builder
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"testing"
+
+	"github.com/prysmaticlabs/go-bitfield"
+	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+)
+
+type roundtrip func(*http.Request) (*http.Response, error)
+
+func (fn roundtrip) RoundTrip(r *http.Request) (*http.Response, error) {
+	return fn(r)
+}
+
+func TestClient_Status(t *testing.T) {
+	ctx := context.Background()
+	statusPath := "/eth/v1/builder/status"
+	hc := &http.Client{
+		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+			defer func() {
+				if r.Body == nil {
+					return
+				}
+				require.NoError(t, r.Body.Close())
+			}()
+			require.Equal(t, statusPath, r.URL.Path)
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBuffer(nil)),
+				Request:    r.Clone(ctx),
+			}, nil
+		}),
+	}
+	c := &Client{
+		hc:      hc,
+		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+	}
+	require.NoError(t, c.Status(ctx))
+	hc = &http.Client{
+		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+			defer func() {
+				if r.Body == nil {
+					return
+				}
+				require.NoError(t, r.Body.Close())
+			}()
+			require.Equal(t, statusPath, r.URL.Path)
+			return &http.Response{
+				StatusCode: http.StatusInternalServerError,
+				Body:       io.NopCloser(bytes.NewBuffer(nil)),
+				Request:    r.Clone(ctx),
+			}, nil
+		}),
+	}
+	c = &Client{
+		hc:      hc,
+		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+	}
+	require.ErrorIs(t, c.Status(ctx), ErrNotOK)
+}
+
+func TestClient_RegisterValidator(t *testing.T) {
+	ctx := context.Background()
+	expectedBody := `{"message":{"fee_recipient":"0x0000000000000000000000000000000000000000","gas_limit":"23","timestamp":"42","pubkey":"0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"}}`
+	expectedPath := "/eth/v1/builder/validators"
+	hc := &http.Client{
+		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+			body, err := io.ReadAll(r.Body)
+			defer func() {
+				require.NoError(t, r.Body.Close())
+			}()
+			require.NoError(t, err)
+			require.Equal(t, expectedBody, string(body))
+			require.Equal(t, expectedPath, r.URL.Path)
+			require.Equal(t, http.MethodPost, r.Method)
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBuffer(nil)),
+				Request:    r.Clone(ctx),
+			}, nil
+		}),
+	}
+	c := &Client{
+		hc:      hc,
+		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+	}
+	reg := &eth.SignedValidatorRegistrationV1{
+		Message: &eth.ValidatorRegistrationV1{
+			FeeRecipient: ezDecode(t, fieldparams.EthBurnAddressHex),
+			GasLimit:     23,
+			Timestamp:    42,
+			Pubkey:       ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+		},
+	}
+	require.NoError(t, c.RegisterValidator(ctx, reg))
+}
+
+func TestClient_GetHeader(t *testing.T) {
+	ctx := context.Background()
+	expectedPath := "/eth/v1/builder/header/23/0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2/0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
+	hc := &http.Client{
+		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+			require.Equal(t, expectedPath, r.URL.Path)
+			return &http.Response{
+				StatusCode: http.StatusInternalServerError,
+				Body:       io.NopCloser(bytes.NewBuffer(nil)),
+				Request:    r.Clone(ctx),
+			}, nil
+		}),
+	}
+	c := &Client{
+		hc:      hc,
+		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+	}
+	var slot types.Slot = 23
+	parentHash := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	pubkey := ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a")
+	_, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+	require.ErrorIs(t, err, ErrNotOK)
+
+	hc = &http.Client{
+		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+			require.Equal(t, expectedPath, r.URL.Path)
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBufferString(testExampleHeaderResponse)),
+				Request:    r.Clone(ctx),
+			}, nil
+		}),
+	}
+	c = &Client{
+		hc:      hc,
+		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+	}
+	h, err := c.GetHeader(ctx, slot, bytesutil.ToBytes32(parentHash), bytesutil.ToBytes48(pubkey))
+	require.NoError(t, err)
+	expectedSig := ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505")
+	require.Equal(t, true, bytes.Equal(expectedSig, h.Signature))
+	expectedTxRoot := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.Equal(t, true, bytes.Equal(expectedTxRoot, h.Message.Header.TransactionsRoot))
+	require.Equal(t, uint64(1), h.Message.Header.GasUsed)
+	value := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
+	require.Equal(t, fmt.Sprintf("%#x", value.SSZBytes()), fmt.Sprintf("%#x", h.Message.Value))
+}
+
+func TestSubmitBlindedBlock(t *testing.T) {
+	ctx := context.Background()
+	hc := &http.Client{
+		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+			require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayload)),
+				Request:    r.Clone(ctx),
+			}, nil
+		}),
+	}
+	c := &Client{
+		hc:      hc,
+		baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+	}
+	sbbb := testSignedBlindedBeaconBlockBellatrix(t)
+	ep, err := c.SubmitBlindedBlock(ctx, sbbb)
+	require.NoError(t, err)
+	require.Equal(t, true, bytes.Equal(ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), ep.ParentHash))
+	bfpg := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
+	require.Equal(t, fmt.Sprintf("%#x", bfpg.SSZBytes()), fmt.Sprintf("%#x", ep.BaseFeePerGas))
+	require.Equal(t, uint64(1), ep.GasLimit)
+}
+
+func testSignedBlindedBeaconBlockBellatrix(t *testing.T) *eth.SignedBlindedBeaconBlockBellatrix {
+	return &eth.SignedBlindedBeaconBlockBellatrix{
+		Block: &eth.BlindedBeaconBlockBellatrix{
+			Slot:          1,
+			ProposerIndex: 1,
+			ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			Body: &eth.BlindedBeaconBlockBodyBellatrix{
+				RandaoReveal: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+				Eth1Data: &eth.Eth1Data{
+					DepositRoot:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					DepositCount: 1,
+					BlockHash:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				},
+				Graffiti: ezDecode(t, "0xdeadbeefc0ffee"),
+				ProposerSlashings: []*eth.ProposerSlashing{
+					{
+						Header_1: &eth.SignedBeaconBlockHeader{
+							Header: &eth.BeaconBlockHeader{
+								Slot:          1,
+								ProposerIndex: 1,
+								ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+						Header_2: &eth.SignedBeaconBlockHeader{
+							Header: &eth.BeaconBlockHeader{
+								Slot:          1,
+								ProposerIndex: 1,
+								ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+					},
+				},
+				AttesterSlashings: []*eth.AttesterSlashing{
+					{
+						Attestation_1: &eth.IndexedAttestation{
+							AttestingIndices: []uint64{1},
+							Data: &eth.AttestationData{
+								Slot:            1,
+								CommitteeIndex:  1,
+								BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								Source: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+								Target: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+						Attestation_2: &eth.IndexedAttestation{
+							AttestingIndices: []uint64{1},
+							Data: &eth.AttestationData{
+								Slot:            1,
+								CommitteeIndex:  1,
+								BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								Source: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+								Target: &eth.Checkpoint{
+									Epoch: 1,
+									Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+								},
+							},
+							Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+					},
+				},
+				Attestations: []*eth.Attestation{
+					{
+						AggregationBits: bitfield.Bitlist{0x01},
+						Data: &eth.AttestationData{
+							Slot:            1,
+							CommitteeIndex:  1,
+							BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							Source: &eth.Checkpoint{
+								Epoch: 1,
+								Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+							Target: &eth.Checkpoint{
+								Epoch: 1,
+								Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							},
+						},
+						Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+					},
+				},
+				Deposits: []*eth.Deposit{
+					{
+						Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
+						Data: &eth.Deposit_Data{
+							PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+							WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+							Amount:                1,
+							Signature:             ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+						},
+					},
+				},
+				VoluntaryExits: []*eth.SignedVoluntaryExit{
+					{
+						Exit: &eth.VoluntaryExit{
+							Epoch:          1,
+							ValidatorIndex: 1,
+						},
+						Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+					},
+				},
+				SyncAggregate: &eth.SyncAggregate{
+					SyncCommitteeSignature: make([]byte, 48),
+					SyncCommitteeBits:      bitfield.Bitvector512{0x01},
+				},
+				ExecutionPayloadHeader: &eth.ExecutionPayloadHeader{
+					ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					FeeRecipient:     ezDecode(t, "0xabcf8e0d4e9587369b2301d0790347320302cc09"),
+					StateRoot:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					ReceiptsRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					LogsBloom:        ezDecode(t, "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
+					PrevRandao:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					BlockNumber:      1,
+					GasLimit:         1,
+					GasUsed:          1,
+					Timestamp:        1,
+					ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					BaseFeePerGas:    []byte(strconv.FormatUint(1, 10)),
+					BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+					TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				},
+			},
+		},
+		Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+	}
+}
+
+func TestRequestLogger(t *testing.T) {
+	wo := WithObserver(&requestLogger{})
+	c, err := NewClient("localhost:3500", wo)
+	require.NoError(t, err)
+
+	ctx := context.Background()
+	hc := &http.Client{
+		Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+			require.Equal(t, getStatus, r.URL.Path)
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       io.NopCloser(bytes.NewBufferString(testExampleExecutionPayload)),
+				Request:    r.Clone(ctx),
+			}, nil
+		}),
+	}
+	c.hc = hc
+	err = c.Status(ctx)
+	require.NoError(t, err)
+}

api/client/builder/errors.go

@@ -0,0 +1,10 @@
+package builder
+
+import "github.com/pkg/errors"
+
+// ErrNotOK is used to indicate when an HTTP request to the Beacon Node API failed with any non-2xx response code.
+// More specific errors may be returned, but an error in reaction to a non-2xx response will always wrap ErrNotOK.
+var ErrNotOK = errors.New("did not receive 2xx response from API")
+
+// ErrNotFound specifically means that a '404 - NOT FOUND' response was received from the API.
+var ErrNotFound = errors.Wrap(ErrNotOK, "recv 404 NotFound response from API")

api/client/builder/testdata/execution-payload.json

@@ -0,0 +1 @@
+{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"14074904626401341155369551180448584754667373453244490859944217516317499064576","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}

api/client/builder/types.go

@@ -0,0 +1,585 @@
+package builder
+
+import (
+	"encoding/json"
+	"fmt"
+	"math/big"
+	"strconv"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+)
+
+type SignedValidatorRegistration struct {
+	*eth.SignedValidatorRegistrationV1
+}
+
+type ValidatorRegistration struct {
+	*eth.ValidatorRegistrationV1
+}
+
+func (r *SignedValidatorRegistration) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Message   *ValidatorRegistration `json:"message,omitempty"`
+		Signature hexutil.Bytes          `json:"signature,omitempty"`
+	}{
+		Message:   &ValidatorRegistration{r.Message},
+		Signature: r.SignedValidatorRegistrationV1.Signature,
+	})
+}
+
+func (r *ValidatorRegistration) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		FeeRecipient hexutil.Bytes `json:"fee_recipient,omitempty"`
+		GasLimit     string        `json:"gas_limit,omitempty"`
+		Timestamp    string        `json:"timestamp,omitempty"`
+		Pubkey       hexutil.Bytes `json:"pubkey,omitempty"`
+	}{
+		FeeRecipient: r.FeeRecipient,
+		GasLimit:     fmt.Sprintf("%d", r.GasLimit),
+		Timestamp:    fmt.Sprintf("%d", r.Timestamp),
+		Pubkey:       r.Pubkey,
+	})
+}
+
+type Uint256 struct {
+	*big.Int
+}
+
+func stringToUint256(s string) Uint256 {
+	bi := new(big.Int)
+	bi.SetString(s, 10)
+	return Uint256{Int: bi}
+}
+
+// sszBytesToUint256 creates a Uint256 from a ssz-style (little-endian byte slice) representation.
+func sszBytesToUint256(b []byte) Uint256 {
+	bi := new(big.Int)
+	return Uint256{Int: bi.SetBytes(bytesutil.ReverseByteOrder(b))}
+}
+
+// SSZBytes creates an ssz-style (little-endian byte slice) representation of the Uint256
+func (s Uint256) SSZBytes() []byte {
+	return bytesutil.ReverseByteOrder(s.Int.Bytes())
+}
+
+var errUnmarshalUint256Failed = errors.New("unable to UnmarshalText into a Uint256 value")
+
+func (s *Uint256) UnmarshalJSON(t []byte) error {
+	start := 0
+	end := len(t)
+	if t[0] == '"' {
+		start += 1
+	}
+	if t[end-1] == '"' {
+		end -= 1
+	}
+	return s.UnmarshalText(t[start:end])
+}
+
+func (s *Uint256) UnmarshalText(t []byte) error {
+	if s.Int == nil {
+		s.Int = big.NewInt(0)
+	}
+	z, ok := s.SetString(string(t), 10)
+	if !ok {
+		return errors.Wrapf(errUnmarshalUint256Failed, "value=%s", string(t))
+	}
+	s.Int = z
+	return nil
+}
+
+func (s Uint256) MarshalJSON() ([]byte, error) {
+	t, err := s.MarshalText()
+	if err != nil {
+		return nil, err
+	}
+	t = append([]byte{'"'}, t...)
+	t = append(t, '"')
+	return t, nil
+}
+
+func (s Uint256) MarshalText() ([]byte, error) {
+	return []byte(s.String()), nil
+}
+
+type Uint64String uint64
+
+func (s *Uint64String) UnmarshalText(t []byte) error {
+	u, err := strconv.ParseUint(string(t), 10, 64)
+	*s = Uint64String(u)
+	return err
+}
+
+func (s Uint64String) MarshalText() ([]byte, error) {
+	return []byte(fmt.Sprintf("%d", s)), nil
+}
+
+type ExecHeaderResponse struct {
+	Version string `json:"version,omitempty"`
+	Data    struct {
+		Signature hexutil.Bytes `json:"signature,omitempty"`
+		Message   *BuilderBid   `json:"message,omitempty"`
+	} `json:"data,omitempty"`
+}
+
+func (ehr *ExecHeaderResponse) ToProto() (*eth.SignedBuilderBid, error) {
+	bb, err := ehr.Data.Message.ToProto()
+	if err != nil {
+		return nil, err
+	}
+	return &eth.SignedBuilderBid{
+		Message:   bb,
+		Signature: ehr.Data.Signature,
+	}, nil
+}
+
+func (bb *BuilderBid) ToProto() (*eth.BuilderBid, error) {
+	header, err := bb.Header.ToProto()
+	if err != nil {
+		return nil, err
+	}
+	return &eth.BuilderBid{
+		Header: header,
+		Value:  bb.Value.SSZBytes(),
+		Pubkey: bb.Pubkey,
+	}, nil
+}
+
+func (h *ExecutionPayloadHeader) ToProto() (*eth.ExecutionPayloadHeader, error) {
+	return &eth.ExecutionPayloadHeader{
+		ParentHash:       h.ParentHash,
+		FeeRecipient:     h.FeeRecipient,
+		StateRoot:        h.StateRoot,
+		ReceiptsRoot:     h.ReceiptsRoot,
+		LogsBloom:        h.LogsBloom,
+		PrevRandao:       h.PrevRandao,
+		BlockNumber:      uint64(h.BlockNumber),
+		GasLimit:         uint64(h.GasLimit),
+		GasUsed:          uint64(h.GasUsed),
+		Timestamp:        uint64(h.Timestamp),
+		ExtraData:        h.ExtraData,
+		BaseFeePerGas:    h.BaseFeePerGas.SSZBytes(),
+		BlockHash:        h.BlockHash,
+		TransactionsRoot: h.TransactionsRoot,
+	}, nil
+}
+
+type BuilderBid struct {
+	Header *ExecutionPayloadHeader `json:"header,omitempty"`
+	Value  Uint256                 `json:"value,omitempty"`
+	Pubkey hexutil.Bytes           `json:"pubkey,omitempty"`
+}
+
+type ExecutionPayloadHeader struct {
+	ParentHash       hexutil.Bytes `json:"parent_hash,omitempty"`
+	FeeRecipient     hexutil.Bytes `json:"fee_recipient,omitempty"`
+	StateRoot        hexutil.Bytes `json:"state_root,omitempty"`
+	ReceiptsRoot     hexutil.Bytes `json:"receipts_root,omitempty"`
+	LogsBloom        hexutil.Bytes `json:"logs_bloom,omitempty"`
+	PrevRandao       hexutil.Bytes `json:"prev_randao,omitempty"`
+	BlockNumber      Uint64String  `json:"block_number,omitempty"`
+	GasLimit         Uint64String  `json:"gas_limit,omitempty"`
+	GasUsed          Uint64String  `json:"gas_used,omitempty"`
+	Timestamp        Uint64String  `json:"timestamp,omitempty"`
+	ExtraData        hexutil.Bytes `json:"extra_data,omitempty"`
+	BaseFeePerGas    Uint256       `json:"base_fee_per_gas,omitempty"`
+	BlockHash        hexutil.Bytes `json:"block_hash,omitempty"`
+	TransactionsRoot hexutil.Bytes `json:"transactions_root,omitempty"`
+	*eth.ExecutionPayloadHeader
+}
+
+func (h *ExecutionPayloadHeader) MarshalJSON() ([]byte, error) {
+	type MarshalCaller ExecutionPayloadHeader
+	return json.Marshal(&MarshalCaller{
+		ParentHash:       h.ExecutionPayloadHeader.ParentHash,
+		FeeRecipient:     h.ExecutionPayloadHeader.FeeRecipient,
+		StateRoot:        h.ExecutionPayloadHeader.StateRoot,
+		ReceiptsRoot:     h.ExecutionPayloadHeader.ReceiptsRoot,
+		LogsBloom:        h.ExecutionPayloadHeader.LogsBloom,
+		PrevRandao:       h.ExecutionPayloadHeader.PrevRandao,
+		BlockNumber:      Uint64String(h.ExecutionPayloadHeader.BlockNumber),
+		GasLimit:         Uint64String(h.ExecutionPayloadHeader.GasLimit),
+		GasUsed:          Uint64String(h.ExecutionPayloadHeader.GasUsed),
+		Timestamp:        Uint64String(h.ExecutionPayloadHeader.Timestamp),
+		ExtraData:        h.ExecutionPayloadHeader.ExtraData,
+		BaseFeePerGas:    sszBytesToUint256(h.ExecutionPayloadHeader.BaseFeePerGas),
+		BlockHash:        h.ExecutionPayloadHeader.BlockHash,
+		TransactionsRoot: h.ExecutionPayloadHeader.TransactionsRoot,
+	})
+}
+
+func (h *ExecutionPayloadHeader) UnmarshalJSON(b []byte) error {
+	type UnmarshalCaller ExecutionPayloadHeader
+	uc := &UnmarshalCaller{}
+	if err := json.Unmarshal(b, uc); err != nil {
+		return err
+	}
+	ep := ExecutionPayloadHeader(*uc)
+	*h = ep
+	var err error
+	h.ExecutionPayloadHeader, err = h.ToProto()
+	return err
+}
+
+type ExecPayloadResponse struct {
+	Version string           `json:"version,omitempty"`
+	Data    ExecutionPayload `json:"data,omitempty"`
+}
+
+type ExecutionPayload struct {
+	ParentHash    hexutil.Bytes   `json:"parent_hash,omitempty"`
+	FeeRecipient  hexutil.Bytes   `json:"fee_recipient,omitempty"`
+	StateRoot     hexutil.Bytes   `json:"state_root,omitempty"`
+	ReceiptsRoot  hexutil.Bytes   `json:"receipts_root,omitempty"`
+	LogsBloom     hexutil.Bytes   `json:"logs_bloom,omitempty"`
+	PrevRandao    hexutil.Bytes   `json:"prev_randao,omitempty"`
+	BlockNumber   Uint64String    `json:"block_number,omitempty"`
+	GasLimit      Uint64String    `json:"gas_limit,omitempty"`
+	GasUsed       Uint64String    `json:"gas_used,omitempty"`
+	Timestamp     Uint64String    `json:"timestamp,omitempty"`
+	ExtraData     hexutil.Bytes   `json:"extra_data,omitempty"`
+	BaseFeePerGas Uint256         `json:"base_fee_per_gas,omitempty"`
+	BlockHash     hexutil.Bytes   `json:"block_hash,omitempty"`
+	Transactions  []hexutil.Bytes `json:"transactions,omitempty"`
+}
+
+func (r *ExecPayloadResponse) ToProto() (*v1.ExecutionPayload, error) {
+	return r.Data.ToProto()
+}
+
+func (p *ExecutionPayload) ToProto() (*v1.ExecutionPayload, error) {
+	txs := make([][]byte, len(p.Transactions))
+	for i := range p.Transactions {
+		txs[i] = p.Transactions[i]
+	}
+	return &v1.ExecutionPayload{
+		ParentHash:    p.ParentHash,
+		FeeRecipient:  p.FeeRecipient,
+		StateRoot:     p.StateRoot,
+		ReceiptsRoot:  p.ReceiptsRoot,
+		LogsBloom:     p.LogsBloom,
+		PrevRandao:    p.PrevRandao,
+		BlockNumber:   uint64(p.BlockNumber),
+		GasLimit:      uint64(p.GasLimit),
+		GasUsed:       uint64(p.GasUsed),
+		Timestamp:     uint64(p.Timestamp),
+		ExtraData:     p.ExtraData,
+		BaseFeePerGas: p.BaseFeePerGas.SSZBytes(),
+		BlockHash:     p.BlockHash,
+		Transactions:  txs,
+	}, nil
+}
+
+type SignedBlindedBeaconBlockBellatrix struct {
+	*eth.SignedBlindedBeaconBlockBellatrix
+}
+
+type BlindedBeaconBlockBellatrix struct {
+	*eth.BlindedBeaconBlockBellatrix
+}
+
+type BlindedBeaconBlockBodyBellatrix struct {
+	*eth.BlindedBeaconBlockBodyBellatrix
+}
+
+func (r *SignedBlindedBeaconBlockBellatrix) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Message   *BlindedBeaconBlockBellatrix `json:"message,omitempty"`
+		Signature hexutil.Bytes                `json:"signature,omitempty"`
+	}{
+		Message:   &BlindedBeaconBlockBellatrix{r.SignedBlindedBeaconBlockBellatrix.Block},
+		Signature: r.SignedBlindedBeaconBlockBellatrix.Signature,
+	})
+}
+
+func (b *BlindedBeaconBlockBellatrix) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Slot          string                           `json:"slot"`
+		ProposerIndex string                           `json:"proposer_index,omitempty"`
+		ParentRoot    hexutil.Bytes                    `json:"parent_root,omitempty"`
+		StateRoot     hexutil.Bytes                    `json:"state_root,omitempty"`
+		Body          *BlindedBeaconBlockBodyBellatrix `json:"body,omitempty"`
+	}{
+		Slot:          fmt.Sprintf("%d", b.Slot),
+		ProposerIndex: fmt.Sprintf("%d", b.ProposerIndex),
+		ParentRoot:    b.ParentRoot,
+		StateRoot:     b.StateRoot,
+		Body:          &BlindedBeaconBlockBodyBellatrix{b.BlindedBeaconBlockBellatrix.Body},
+	})
+}
+
+type ProposerSlashing struct {
+	*eth.ProposerSlashing
+}
+
+func (s *ProposerSlashing) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		SignedHeader1 *SignedBeaconBlockHeader `json:"signed_header_1,omitempty"`
+		SignedHeader2 *SignedBeaconBlockHeader `json:"signed_header_2,omitempty"`
+	}{
+		SignedHeader1: &SignedBeaconBlockHeader{s.ProposerSlashing.Header_1},
+		SignedHeader2: &SignedBeaconBlockHeader{s.ProposerSlashing.Header_2},
+	})
+}
+
+type SignedBeaconBlockHeader struct {
+	*eth.SignedBeaconBlockHeader
+}
+
+func (h *SignedBeaconBlockHeader) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Header    *BeaconBlockHeader `json:"message,omitempty"`
+		Signature hexutil.Bytes      `json:"signature,omitempty"`
+	}{
+		Header:    &BeaconBlockHeader{h.SignedBeaconBlockHeader.Header},
+		Signature: h.SignedBeaconBlockHeader.Signature,
+	})
+}
+
+type BeaconBlockHeader struct {
+	*eth.BeaconBlockHeader
+}
+
+func (h *BeaconBlockHeader) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Slot          string        `json:"slot,omitempty"`
+		ProposerIndex string        `json:"proposer_index,omitempty"`
+		ParentRoot    hexutil.Bytes `json:"parent_root,omitempty"`
+		StateRoot     hexutil.Bytes `json:"state_root,omitempty"`
+		BodyRoot      hexutil.Bytes `json:"body_root,omitempty"`
+	}{
+		Slot:          fmt.Sprintf("%d", h.BeaconBlockHeader.Slot),
+		ProposerIndex: fmt.Sprintf("%d", h.BeaconBlockHeader.ProposerIndex),
+		ParentRoot:    h.BeaconBlockHeader.ParentRoot,
+		StateRoot:     h.BeaconBlockHeader.StateRoot,
+		BodyRoot:      h.BeaconBlockHeader.BodyRoot,
+	})
+}
+
+type IndexedAttestation struct {
+	*eth.IndexedAttestation
+}
+
+func (a *IndexedAttestation) MarshalJSON() ([]byte, error) {
+	indices := make([]string, len(a.IndexedAttestation.AttestingIndices))
+	for i := range a.IndexedAttestation.AttestingIndices {
+		indices[i] = fmt.Sprintf("%d", a.AttestingIndices[i])
+	}
+	return json.Marshal(struct {
+		AttestingIndices []string         `json:"attesting_indices,omitempty"`
+		Data             *AttestationData `json:"data,omitempty"`
+		Signature        hexutil.Bytes    `json:"signature,omitempty"`
+	}{
+		AttestingIndices: indices,
+		Data:             &AttestationData{a.IndexedAttestation.Data},
+		Signature:        a.IndexedAttestation.Signature,
+	})
+}
+
+type AttesterSlashing struct {
+	*eth.AttesterSlashing
+}
+
+func (s *AttesterSlashing) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Attestation1 *IndexedAttestation `json:"attestation_1,omitempty"`
+		Attestation2 *IndexedAttestation `json:"attestation_2,omitempty"`
+	}{
+		Attestation1: &IndexedAttestation{s.Attestation_1},
+		Attestation2: &IndexedAttestation{s.Attestation_2},
+	})
+}
+
+type Checkpoint struct {
+	*eth.Checkpoint
+}
+
+func (c *Checkpoint) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Epoch string        `json:"epoch,omitempty"`
+		Root  hexutil.Bytes `json:"root,omitempty"`
+	}{
+		Epoch: fmt.Sprintf("%d", c.Checkpoint.Epoch),
+		Root:  c.Checkpoint.Root,
+	})
+}
+
+type AttestationData struct {
+	*eth.AttestationData
+}
+
+func (a *AttestationData) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Slot            string        `json:"slot,omitempty"`
+		Index           string        `json:"index,omitempty"`
+		BeaconBlockRoot hexutil.Bytes `json:"beacon_block_root,omitempty"`
+		Source          *Checkpoint   `json:"source,omitempty"`
+		Target          *Checkpoint   `json:"target,omitempty"`
+	}{
+		Slot:            fmt.Sprintf("%d", a.AttestationData.Slot),
+		Index:           fmt.Sprintf("%d", a.AttestationData.CommitteeIndex),
+		BeaconBlockRoot: a.AttestationData.BeaconBlockRoot,
+		Source:          &Checkpoint{a.AttestationData.Source},
+		Target:          &Checkpoint{a.AttestationData.Target},
+	})
+}
+
+type Attestation struct {
+	*eth.Attestation
+}
+
+func (a *Attestation) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		AggregationBits hexutil.Bytes    `json:"aggregation_bits,omitempty"`
+		Data            *AttestationData `json:"data,omitempty"`
+		Signature       hexutil.Bytes    `json:"signature,omitempty" ssz-size:"96"`
+	}{
+		AggregationBits: hexutil.Bytes(a.Attestation.AggregationBits),
+		Data:            &AttestationData{a.Attestation.Data},
+		Signature:       a.Attestation.Signature,
+	})
+}
+
+type DepositData struct {
+	*eth.Deposit_Data
+}
+
+func (d *DepositData) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		PublicKey             hexutil.Bytes `json:"pubkey,omitempty"`
+		WithdrawalCredentials hexutil.Bytes `json:"withdrawal_credentials,omitempty"`
+		Amount                string        `json:"amount,omitempty"`
+		Signature             hexutil.Bytes `json:"signature,omitempty"`
+	}{
+		PublicKey:             d.PublicKey,
+		WithdrawalCredentials: d.WithdrawalCredentials,
+		Amount:                fmt.Sprintf("%d", d.Amount),
+		Signature:             d.Signature,
+	})
+}
+
+type Deposit struct {
+	*eth.Deposit
+}
+
+func (d *Deposit) MarshalJSON() ([]byte, error) {
+	proof := make([]hexutil.Bytes, len(d.Proof))
+	for i := range d.Proof {
+		proof[i] = d.Proof[i]
+	}
+	return json.Marshal(struct {
+		Proof []hexutil.Bytes `json:"proof"`
+		Data  *DepositData    `json:"data"`
+	}{
+		Proof: proof,
+		Data:  &DepositData{Deposit_Data: d.Deposit.Data},
+	})
+}
+
+type SignedVoluntaryExit struct {
+	*eth.SignedVoluntaryExit
+}
+
+func (sve *SignedVoluntaryExit) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Message   *VoluntaryExit `json:"message,omitempty"`
+		Signature hexutil.Bytes  `json:"signature,omitempty"`
+	}{
+		Signature: sve.SignedVoluntaryExit.Signature,
+		Message:   &VoluntaryExit{sve.SignedVoluntaryExit.Exit},
+	})
+}
+
+type VoluntaryExit struct {
+	*eth.VoluntaryExit
+}
+
+func (ve *VoluntaryExit) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Epoch          string `json:"epoch,omitempty"`
+		ValidatorIndex string `json:"validator_index,omitempty"`
+	}{
+		Epoch:          fmt.Sprintf("%d", ve.Epoch),
+		ValidatorIndex: fmt.Sprintf("%d", ve.ValidatorIndex),
+	})
+}
+
+type SyncAggregate struct {
+	*eth.SyncAggregate
+}
+
+func (s *SyncAggregate) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		SyncCommitteeBits      hexutil.Bytes `json:"sync_committee_bits,omitempty"`
+		SyncCommitteeSignature hexutil.Bytes `json:"sync_committee_signature,omitempty"`
+	}{
+		SyncCommitteeBits:      hexutil.Bytes(s.SyncAggregate.SyncCommitteeBits),
+		SyncCommitteeSignature: s.SyncAggregate.SyncCommitteeSignature,
+	})
+}
+
+type Eth1Data struct {
+	*eth.Eth1Data
+}
+
+func (e *Eth1Data) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		DepositRoot  hexutil.Bytes `json:"deposit_root,omitempty"`
+		DepositCount string        `json:"deposit_count,omitempty"`
+		BlockHash    hexutil.Bytes `json:"block_hash,omitempty"`
+	}{
+		DepositRoot:  e.DepositRoot,
+		DepositCount: fmt.Sprintf("%d", e.DepositCount),
+		BlockHash:    e.BlockHash,
+	})
+}
+
+func (b *BlindedBeaconBlockBodyBellatrix) MarshalJSON() ([]byte, error) {
+	sve := make([]*SignedVoluntaryExit, len(b.BlindedBeaconBlockBodyBellatrix.VoluntaryExits))
+	for i := range b.BlindedBeaconBlockBodyBellatrix.VoluntaryExits {
+		sve[i] = &SignedVoluntaryExit{SignedVoluntaryExit: b.BlindedBeaconBlockBodyBellatrix.VoluntaryExits[i]}
+	}
+	deps := make([]*Deposit, len(b.BlindedBeaconBlockBodyBellatrix.Deposits))
+	for i := range b.BlindedBeaconBlockBodyBellatrix.Deposits {
+		deps[i] = &Deposit{Deposit: b.BlindedBeaconBlockBodyBellatrix.Deposits[i]}
+	}
+	atts := make([]*Attestation, len(b.BlindedBeaconBlockBodyBellatrix.Attestations))
+	for i := range b.BlindedBeaconBlockBodyBellatrix.Attestations {
+		atts[i] = &Attestation{Attestation: b.BlindedBeaconBlockBodyBellatrix.Attestations[i]}
+	}
+	atsl := make([]*AttesterSlashing, len(b.BlindedBeaconBlockBodyBellatrix.AttesterSlashings))
+	for i := range b.BlindedBeaconBlockBodyBellatrix.AttesterSlashings {
+		atsl[i] = &AttesterSlashing{AttesterSlashing: b.BlindedBeaconBlockBodyBellatrix.AttesterSlashings[i]}
+	}
+	pros := make([]*ProposerSlashing, len(b.BlindedBeaconBlockBodyBellatrix.ProposerSlashings))
+	for i := range b.BlindedBeaconBlockBodyBellatrix.ProposerSlashings {
+		pros[i] = &ProposerSlashing{ProposerSlashing: b.BlindedBeaconBlockBodyBellatrix.ProposerSlashings[i]}
+	}
+	return json.Marshal(struct {
+		RandaoReveal           hexutil.Bytes           `json:"randao_reveal,omitempty"`
+		Eth1Data               *Eth1Data               `json:"eth1_data,omitempty"`
+		Graffiti               hexutil.Bytes           `json:"graffiti,omitempty"`
+		ProposerSlashings      []*ProposerSlashing     `json:"proposer_slashings,omitempty"`
+		AttesterSlashings      []*AttesterSlashing     `json:"attester_slashings,omitempty"`
+		Attestations           []*Attestation          `json:"attestations,omitempty"`
+		Deposits               []*Deposit              `json:"deposits,omitempty"`
+		VoluntaryExits         []*SignedVoluntaryExit  `json:"voluntary_exits,omitempty"`
+		SyncAggregate          *SyncAggregate          `json:"sync_aggregate,omitempty"`
+		ExecutionPayloadHeader *ExecutionPayloadHeader `json:"execution_payload_header,omitempty"`
+	}{
+		RandaoReveal:           b.RandaoReveal,
+		Eth1Data:               &Eth1Data{b.BlindedBeaconBlockBodyBellatrix.Eth1Data},
+		Graffiti:               b.BlindedBeaconBlockBodyBellatrix.Graffiti,
+		ProposerSlashings:      pros,
+		AttesterSlashings:      atsl,
+		Attestations:           atts,
+		Deposits:               deps,
+		VoluntaryExits:         sve,
+		SyncAggregate:          &SyncAggregate{b.BlindedBeaconBlockBodyBellatrix.SyncAggregate},
+		ExecutionPayloadHeader: &ExecutionPayloadHeader{ExecutionPayloadHeader: b.BlindedBeaconBlockBodyBellatrix.ExecutionPayloadHeader},
+	})
+}

api/client/builder/types_test.go

@@ -0,0 +1,726 @@
+package builder
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"math/big"
+	"os"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/prysmaticlabs/go-bitfield"
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+)
+
+func ezDecode(t *testing.T, s string) []byte {
+	v, err := hexutil.Decode(s)
+	require.NoError(t, err)
+	return v
+}
+
+func TestSignedValidatorRegistration_MarshalJSON(t *testing.T) {
+	svr := &eth.SignedValidatorRegistrationV1{
+		Message: &eth.ValidatorRegistrationV1{
+			FeeRecipient: make([]byte, 20),
+			GasLimit:     0,
+			Timestamp:    0,
+			Pubkey:       make([]byte, 48),
+		},
+		Signature: make([]byte, 96),
+	}
+	je, err := json.Marshal(&SignedValidatorRegistration{SignedValidatorRegistrationV1: svr})
+	require.NoError(t, err)
+	// decode with a struct w/ plain strings so we can check the string encoding of the hex fields
+	un := struct {
+		Message struct {
+			FeeRecipient string `json:"fee_recipient"`
+			Pubkey       string `json:"pubkey"`
+		} `json:"message"`
+		Signature string `json:"signature"`
+	}{}
+	require.NoError(t, json.Unmarshal(je, &un))
+	require.Equal(t, "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", un.Signature)
+	require.Equal(t, "0x0000000000000000000000000000000000000000", un.Message.FeeRecipient)
+	require.Equal(t, "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000", un.Message.Pubkey)
+}
+
+var testExampleHeaderResponse = `{
+  "version": "bellatrix",
+  "data": {
+    "message": {
+      "header": {
+        "parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+        "state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+        "prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "block_number": "1",
+        "gas_limit": "1",
+        "gas_used": "1",
+        "timestamp": "1",
+        "extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "base_fee_per_gas": "452312848583266388373324160190187140051835877600158453279131187530910662656",
+        "block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+        "transactions_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"
+      },
+      "value": "652312848583266388373324160190187140051835877600158453279131187530910662656",
+      "pubkey": "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
+    },
+    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+  }
+}`
+
+func TestExecutionHeaderResponseUnmarshal(t *testing.T) {
+	hr := &ExecHeaderResponse{}
+	require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponse), hr))
+	cases := []struct {
+		expected string
+		actual   string
+		name     string
+	}{
+		{
+			expected: "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505",
+			actual:   hexutil.Encode(hr.Data.Signature),
+			name:     "Signature",
+		},
+		{
+			expected: "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a",
+			actual:   hexutil.Encode(hr.Data.Message.Pubkey),
+			name:     "ExecHeaderResponse.Pubkey",
+		},
+		{
+			expected: "652312848583266388373324160190187140051835877600158453279131187530910662656",
+			actual:   hr.Data.Message.Value.String(),
+			name:     "ExecHeaderResponse.Value",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(hr.Data.Message.Header.ParentHash),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ParentHash",
+		},
+		{
+			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+			actual:   hexutil.Encode(hr.Data.Message.Header.FeeRecipient),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.FeeRecipient",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(hr.Data.Message.Header.StateRoot),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.StateRoot",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(hr.Data.Message.Header.ReceiptsRoot),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ReceiptsRoot",
+		},
+		{
+			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+			actual:   hexutil.Encode(hr.Data.Message.Header.LogsBloom),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.LogsBloom",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(hr.Data.Message.Header.PrevRandao),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.PrevRandao",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BlockNumber),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockNumber",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasLimit),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasLimit",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasUsed),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasUsed",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.Timestamp),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.Timestamp",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(hr.Data.Message.Header.ExtraData),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ExtraData",
+		},
+		{
+			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
+			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BaseFeePerGas),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BaseFeePerGas",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(hr.Data.Message.Header.BlockHash),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockHash",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(hr.Data.Message.Header.TransactionsRoot),
+			name:     "ExecHeaderResponse.ExecutionPayloadHeader.TransactionsRoot",
+		},
+	}
+	for _, c := range cases {
+		require.Equal(t, c.expected, c.actual, fmt.Sprintf("unexpected value for field %s", c.name))
+	}
+}
+
+func TestExecutionHeaderResponseToProto(t *testing.T) {
+	bfpg := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
+	v := stringToUint256("652312848583266388373324160190187140051835877600158453279131187530910662656")
+	hr := &ExecHeaderResponse{}
+	require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponse), hr))
+	p, err := hr.ToProto()
+	require.NoError(t, err)
+	signature, err := hexutil.Decode("0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505")
+	require.NoError(t, err)
+	pubkey, err := hexutil.Decode("0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a")
+	require.NoError(t, err)
+	parentHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	feeRecipient, err := hexutil.Decode("0xabcf8e0d4e9587369b2301d0790347320302cc09")
+	require.NoError(t, err)
+	stateRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	receiptsRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	logsBloom, err := hexutil.Decode("0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000")
+	require.NoError(t, err)
+	prevRandao, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	extraData, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	blockHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	txRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+
+	expected := &eth.SignedBuilderBid{
+		Message: &eth.BuilderBid{
+			Header: &eth.ExecutionPayloadHeader{
+				ParentHash:       parentHash,
+				FeeRecipient:     feeRecipient,
+				StateRoot:        stateRoot,
+				ReceiptsRoot:     receiptsRoot,
+				LogsBloom:        logsBloom,
+				PrevRandao:       prevRandao,
+				BlockNumber:      1,
+				GasLimit:         1,
+				GasUsed:          1,
+				Timestamp:        1,
+				ExtraData:        extraData,
+				BaseFeePerGas:    bfpg.SSZBytes(),
+				BlockHash:        blockHash,
+				TransactionsRoot: txRoot,
+			},
+			Value:  v.SSZBytes(),
+			Pubkey: pubkey,
+		},
+		Signature: signature,
+	}
+	require.DeepEqual(t, expected, p)
+}
+
+var testExampleExecutionPayload = `{
+  "version": "bellatrix",
+  "data": {
+    "parent_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "fee_recipient": "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+    "state_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "receipts_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "logs_bloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    "prev_randao": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "block_number": "1",
+    "gas_limit": "1",
+    "gas_used": "1",
+    "timestamp": "1",
+    "extra_data": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "base_fee_per_gas": "452312848583266388373324160190187140051835877600158453279131187530910662656",
+    "block_hash": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "transactions": [
+      "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
+    ]
+  }
+}`
+
+func TestExecutionPayloadResponseUnmarshal(t *testing.T) {
+	epr := &ExecPayloadResponse{}
+	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), epr))
+	cases := []struct {
+		expected string
+		actual   string
+		name     string
+	}{
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ParentHash),
+			name:     "ExecPayloadResponse.ExecutionPayload.ParentHash",
+		},
+		{
+			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
+			actual:   hexutil.Encode(epr.Data.FeeRecipient),
+			name:     "ExecPayloadResponse.ExecutionPayload.FeeRecipient",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.StateRoot),
+			name:     "ExecPayloadResponse.ExecutionPayload.StateRoot",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ReceiptsRoot),
+			name:     "ExecPayloadResponse.ExecutionPayload.ReceiptsRoot",
+		},
+		{
+			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+			actual:   hexutil.Encode(epr.Data.LogsBloom),
+			name:     "ExecPayloadResponse.ExecutionPayload.LogsBloom",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.PrevRandao),
+			name:     "ExecPayloadResponse.ExecutionPayload.PrevRandao",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", epr.Data.BlockNumber),
+			name:     "ExecPayloadResponse.ExecutionPayload.BlockNumber",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", epr.Data.GasLimit),
+			name:     "ExecPayloadResponse.ExecutionPayload.GasLimit",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", epr.Data.GasUsed),
+			name:     "ExecPayloadResponse.ExecutionPayload.GasUsed",
+		},
+		{
+			expected: "1",
+			actual:   fmt.Sprintf("%d", epr.Data.Timestamp),
+			name:     "ExecPayloadResponse.ExecutionPayload.Timestamp",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.ExtraData),
+			name:     "ExecPayloadResponse.ExecutionPayload.ExtraData",
+		},
+		{
+			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
+			actual:   fmt.Sprintf("%d", epr.Data.BaseFeePerGas),
+			name:     "ExecPayloadResponse.ExecutionPayload.BaseFeePerGas",
+		},
+		{
+			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+			actual:   hexutil.Encode(epr.Data.BlockHash),
+			name:     "ExecPayloadResponse.ExecutionPayload.BlockHash",
+		},
+	}
+	for _, c := range cases {
+		require.Equal(t, c.expected, c.actual, fmt.Sprintf("unexpected value for field %s", c.name))
+	}
+	require.Equal(t, 1, len(epr.Data.Transactions))
+	txHash := "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
+	require.Equal(t, txHash, hexutil.Encode(epr.Data.Transactions[0]))
+}
+
+func TestExecutionPayloadResponseToProto(t *testing.T) {
+	hr := &ExecPayloadResponse{}
+	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), hr))
+	p, err := hr.ToProto()
+	require.NoError(t, err)
+
+	parentHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	feeRecipient, err := hexutil.Decode("0xabcf8e0d4e9587369b2301d0790347320302cc09")
+	require.NoError(t, err)
+	stateRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	receiptsRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	logsBloom, err := hexutil.Decode("0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000")
+	require.NoError(t, err)
+	prevRandao, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	extraData, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+	blockHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
+	require.NoError(t, err)
+
+	tx, err := hexutil.Decode("0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86")
+	require.NoError(t, err)
+	txList := [][]byte{tx}
+
+	bfpg := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
+	expected := &v1.ExecutionPayload{
+		ParentHash:    parentHash,
+		FeeRecipient:  feeRecipient,
+		StateRoot:     stateRoot,
+		ReceiptsRoot:  receiptsRoot,
+		LogsBloom:     logsBloom,
+		PrevRandao:    prevRandao,
+		BlockNumber:   1,
+		GasLimit:      1,
+		GasUsed:       1,
+		Timestamp:     1,
+		ExtraData:     extraData,
+		BaseFeePerGas: bfpg.SSZBytes(),
+		BlockHash:     blockHash,
+		Transactions:  txList,
+	}
+	require.DeepEqual(t, expected, p)
+}
+
+func pbEth1Data() *eth.Eth1Data {
+	return &eth.Eth1Data{
+		DepositRoot:  make([]byte, 32),
+		DepositCount: 23,
+		BlockHash:    make([]byte, 32),
+	}
+}
+
+func TestEth1DataMarshal(t *testing.T) {
+	ed := &Eth1Data{
+		Eth1Data: pbEth1Data(),
+	}
+	b, err := json.Marshal(ed)
+	require.NoError(t, err)
+	expected := `{"deposit_root":"0x0000000000000000000000000000000000000000000000000000000000000000","deposit_count":"23","block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000"}`
+	require.Equal(t, expected, string(b))
+}
+
+func pbSyncAggregate() *eth.SyncAggregate {
+	return &eth.SyncAggregate{
+		SyncCommitteeSignature: make([]byte, 48),
+		SyncCommitteeBits:      bitfield.Bitvector512{0x01},
+	}
+}
+
+func TestSyncAggregate_MarshalJSON(t *testing.T) {
+	sa := &SyncAggregate{pbSyncAggregate()}
+	b, err := json.Marshal(sa)
+	require.NoError(t, err)
+	expected := `{"sync_committee_bits":"0x01","sync_committee_signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}`
+	require.Equal(t, expected, string(b))
+}
+
+func pbDeposit(t *testing.T) *eth.Deposit {
+	return &eth.Deposit{
+		Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
+		Data: &eth.Deposit_Data{
+			PublicKey:             ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"),
+			WithdrawalCredentials: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			Amount:                1,
+			Signature:             ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+		},
+	}
+}
+
+func TestDeposit_MarshalJSON(t *testing.T) {
+	d := &Deposit{
+		Deposit: pbDeposit(t),
+	}
+	b, err := json.Marshal(d)
+	require.NoError(t, err)
+	expected := `{"proof":["0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"],"data":{"pubkey":"0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a","withdrawal_credentials":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","amount":"1","signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}}`
+	require.Equal(t, expected, string(b))
+}
+
+func pbSignedVoluntaryExit(t *testing.T) *eth.SignedVoluntaryExit {
+	return &eth.SignedVoluntaryExit{
+		Exit: &eth.VoluntaryExit{
+			Epoch:          1,
+			ValidatorIndex: 1,
+		},
+		Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+	}
+}
+
+func TestVoluntaryExit(t *testing.T) {
+	ve := &SignedVoluntaryExit{
+		SignedVoluntaryExit: pbSignedVoluntaryExit(t),
+	}
+	b, err := json.Marshal(ve)
+	require.NoError(t, err)
+	expected := `{"message":{"epoch":"1","validator_index":"1"},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}`
+	require.Equal(t, expected, string(b))
+}
+
+func pbAttestation(t *testing.T) *eth.Attestation {
+	return &eth.Attestation{
+		AggregationBits: bitfield.Bitlist{0x01},
+		Data: &eth.AttestationData{
+			Slot:            1,
+			CommitteeIndex:  1,
+			BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			Source: &eth.Checkpoint{
+				Epoch: 1,
+				Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			},
+			Target: &eth.Checkpoint{
+				Epoch: 1,
+				Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			},
+		},
+		Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+	}
+}
+
+func TestAttestationMarshal(t *testing.T) {
+	a := &Attestation{
+		Attestation: pbAttestation(t),
+	}
+	b, err := json.Marshal(a)
+	require.NoError(t, err)
+	expected := `{"aggregation_bits":"0x01","data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}`
+	require.Equal(t, expected, string(b))
+}
+
+func pbAttesterSlashing(t *testing.T) *eth.AttesterSlashing {
+	return &eth.AttesterSlashing{
+		Attestation_1: &eth.IndexedAttestation{
+			AttestingIndices: []uint64{1},
+			Signature:        ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+			Data: &eth.AttestationData{
+				Slot:            1,
+				CommitteeIndex:  1,
+				BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				Source: &eth.Checkpoint{
+					Epoch: 1,
+					Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				},
+				Target: &eth.Checkpoint{
+					Epoch: 1,
+					Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				},
+			},
+		},
+		Attestation_2: &eth.IndexedAttestation{
+			AttestingIndices: []uint64{1},
+			Signature:        ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+			Data: &eth.AttestationData{
+				Slot:            1,
+				CommitteeIndex:  1,
+				BeaconBlockRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				Source: &eth.Checkpoint{
+					Epoch: 1,
+					Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				},
+				Target: &eth.Checkpoint{
+					Epoch: 1,
+					Root:  ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				},
+			},
+		},
+	}
+}
+
+func TestAttesterSlashing_MarshalJSON(t *testing.T) {
+	as := &AttesterSlashing{
+		AttesterSlashing: pbAttesterSlashing(t),
+	}
+	b, err := json.Marshal(as)
+	require.NoError(t, err)
+	expected := `{"attestation_1":{"attesting_indices":["1"],"data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"},"attestation_2":{"attesting_indices":["1"],"data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}}`
+	require.Equal(t, expected, string(b))
+}
+
+func pbProposerSlashing(t *testing.T) *eth.ProposerSlashing {
+	return &eth.ProposerSlashing{
+		Header_1: &eth.SignedBeaconBlockHeader{
+			Header: &eth.BeaconBlockHeader{
+				Slot:          1,
+				ProposerIndex: 1,
+				ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			},
+			Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+		},
+		Header_2: &eth.SignedBeaconBlockHeader{
+			Header: &eth.BeaconBlockHeader{
+				Slot:          1,
+				ProposerIndex: 1,
+				ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+				BodyRoot:      ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+			},
+			Signature: ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+		},
+	}
+}
+
+func TestProposerSlashings(t *testing.T) {
+	ps := &ProposerSlashing{ProposerSlashing: pbProposerSlashing(t)}
+	b, err := json.Marshal(ps)
+	require.NoError(t, err)
+	expected := `{"signed_header_1":{"message":{"slot":"1","proposer_index":"1","parent_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","body_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"},"signed_header_2":{"message":{"slot":"1","proposer_index":"1","parent_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","body_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}}`
+	require.Equal(t, expected, string(b))
+}
+
+func pbExecutionPayloadHeader(t *testing.T) *eth.ExecutionPayloadHeader {
+	bfpg := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
+	return &eth.ExecutionPayloadHeader{
+		ParentHash:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		FeeRecipient:     ezDecode(t, "0xabcf8e0d4e9587369b2301d0790347320302cc09"),
+		StateRoot:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		ReceiptsRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		LogsBloom:        ezDecode(t, "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
+		PrevRandao:       ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		BlockNumber:      1,
+		GasLimit:         1,
+		GasUsed:          1,
+		Timestamp:        1,
+		ExtraData:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		BaseFeePerGas:    bfpg.SSZBytes(),
+		BlockHash:        ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		TransactionsRoot: ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+	}
+}
+
+func TestExecutionPayloadHeader_MarshalJSON(t *testing.T) {
+	h := &ExecutionPayloadHeader{
+		ExecutionPayloadHeader: pbExecutionPayloadHeader(t),
+	}
+	b, err := json.Marshal(h)
+	require.NoError(t, err)
+	expected := `{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"452312848583266388373324160190187140051835877600158453279131187530910662656","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}`
+	require.Equal(t, expected, string(b))
+}
+
+var testBuilderBid = `{
+    "version":"bellatrix",
+	"data":{
+		"message":{
+			"header":{
+				"parent_hash":"0xa0513a503d5bd6e89a144c3268e5b7e9da9dbf63df125a360e3950a7d0d67131",
+				"fee_recipient":"0xdfb434922631787e43725c6b926e989875125751",
+				"state_root":"0xca3149fa9e37db08d1cd49c9061db1002ef1cd58db2210f2115c8c989b2bdf45",
+				"receipts_root":"0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+				"logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+				"prev_randao":"0xc2fa210081542a87f334b7b14a2da3275e4b281dd77b007bcfcb10e34c42052e",
+				"block_number":"1",
+				"gas_limit":"10000000",
+				"gas_used":"0",
+				"timestamp":"4660",
+				"extra_data":"0x",
+				"base_fee_per_gas":"7",
+				"block_hash":"0x10746fa06c248e7eacd4ff8ad8b48a826c227387ee31a6aa5eb4d83ddad34f07",
+				"transactions_root":"0x7ffe241ea60187fdb0187bfa22de35d1f9bed7ab061d9401fd47e34a54fbede1"
+			},
+			"value":"452312848583266388373324160190187140051835877600158453279131187530910662656",
+			"pubkey":"0x8645866c95cbc2e08bc77ccad473540eddf4a1f51a2a8edc8d7a673824218f7f68fe565f1ab38dadd5c855b45bbcec95"
+		},
+		"signature":"0x9183ebc1edf9c3ab2bbd7abdc3b59c6b249d6647b5289a97eea36d9d61c47f12e283f64d928b1e7f5b8a5182b714fa921954678ea28ca574f5f232b2f78cf8900915a2993b396e3471e0655291fec143a300d41408f66478c8208e0f9be851dc"
+	}
+}`
+
+func TestBuilderBidUnmarshalUint256(t *testing.T) {
+	base10 := "452312848583266388373324160190187140051835877600158453279131187530910662656"
+	var expectedValue big.Int
+	require.NoError(t, expectedValue.UnmarshalText([]byte(base10)))
+	r := &ExecHeaderResponse{}
+	require.NoError(t, json.Unmarshal([]byte(testBuilderBid), r))
+	//require.Equal(t, expectedValue, r.Data.Message.Value)
+	marshaled := r.Data.Message.Value.String()
+	require.Equal(t, base10, marshaled)
+	require.Equal(t, 0, expectedValue.Cmp(r.Data.Message.Value.Int))
+}
+
+func TestMathBigUnmarshal(t *testing.T) {
+	base10 := "452312848583266388373324160190187140051835877600158453279131187530910662656"
+	var expectedValue big.Int
+	require.NoError(t, expectedValue.UnmarshalText([]byte(base10)))
+	marshaled, err := expectedValue.MarshalText()
+	require.NoError(t, err)
+	require.Equal(t, base10, string(marshaled))
+
+	var u256 Uint256
+	require.NoError(t, u256.UnmarshalText([]byte("452312848583266388373324160190187140051835877600158453279131187530910662656")))
+}
+
+func TestUint256Unmarshal(t *testing.T) {
+	base10 := "452312848583266388373324160190187140051835877600158453279131187530910662656"
+	bi := new(big.Int)
+	bi, ok := bi.SetString(base10, 10)
+	require.Equal(t, true, ok)
+	s := struct {
+		BigNumber Uint256 `json:"big_number"`
+	}{
+		BigNumber: Uint256{Int: bi},
+	}
+	m, err := json.Marshal(s)
+	require.NoError(t, err)
+	expected := `{"big_number":"452312848583266388373324160190187140051835877600158453279131187530910662656"}`
+	require.Equal(t, expected, string(m))
+}
+
+func TestMarshalBlindedBeaconBlockBodyBellatrix(t *testing.T) {
+	expected, err := os.ReadFile("testdata/blinded-block.json")
+	require.NoError(t, err)
+	b := &BlindedBeaconBlockBellatrix{BlindedBeaconBlockBellatrix: &eth.BlindedBeaconBlockBellatrix{
+		Slot:          1,
+		ProposerIndex: 1,
+		ParentRoot:    ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		StateRoot:     ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"),
+		Body: &eth.BlindedBeaconBlockBodyBellatrix{
+			RandaoReveal:           ezDecode(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"),
+			Eth1Data:               pbEth1Data(),
+			Graffiti:               ezDecode(t, "0xdeadbeefc0ffee"),
+			ProposerSlashings:      []*eth.ProposerSlashing{pbProposerSlashing(t)},
+			AttesterSlashings:      []*eth.AttesterSlashing{pbAttesterSlashing(t)},
+			Attestations:           []*eth.Attestation{pbAttestation(t)},
+			Deposits:               []*eth.Deposit{pbDeposit(t)},
+			VoluntaryExits:         []*eth.SignedVoluntaryExit{pbSignedVoluntaryExit(t)},
+			SyncAggregate:          pbSyncAggregate(),
+			ExecutionPayloadHeader: pbExecutionPayloadHeader(t),
+		},
+	}}
+	m, err := json.Marshal(b)
+	require.NoError(t, err)
+	// string error output is easier to deal with
+	// -1 end slice index on expected is to get rid of trailing newline
+	// if you update this fixture and this test breaks, you probably removed the trailing newline
+	require.Equal(t, string(expected[0:len(expected)-1]), string(m))
+}
+
+func TestRoundTripUint256(t *testing.T) {
+	vs := "452312848583266388373324160190187140051835877600158453279131187530910662656"
+	u := stringToUint256(vs)
+	sb := u.SSZBytes()
+	uu := sszBytesToUint256(sb)
+	require.Equal(t, true, bytes.Equal(u.SSZBytes(), uu.SSZBytes()))
+	require.Equal(t, vs, uu.String())
+}
+
+func TestRoundTripProtoUint256(t *testing.T) {
+	h := pbExecutionPayloadHeader(t)
+	h.BaseFeePerGas = []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}
+	hm := &ExecutionPayloadHeader{ExecutionPayloadHeader: h}
+	m, err := json.Marshal(hm)
+	require.NoError(t, err)
+	hu := &ExecutionPayloadHeader{}
+	require.NoError(t, json.Unmarshal(m, hu))
+	hp, err := hu.ToProto()
+	require.NoError(t, err)
+	require.DeepEqual(t, h.BaseFeePerGas, hp.BaseFeePerGas)
+}
+
+func TestExecutionPayloadHeaderRoundtrip(t *testing.T) {
+	expected, err := os.ReadFile("testdata/execution-payload.json")
+	require.NoError(t, err)
+	hu := &ExecutionPayloadHeader{}
+	require.NoError(t, json.Unmarshal(expected, hu))
+	m, err := json.Marshal(hu)
+	require.NoError(t, err)
+	require.DeepEqual(t, string(expected[0:len(expected)-1]), string(m))
+}

beacon-chain/blockchain/BUILD.bazel

@@ -64,6 +64,7 @@ go_library(
         "//config/features:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/forks/bellatrix:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",

beacon-chain/blockchain/error.go

@@ -27,6 +27,8 @@ var (
 	errWSBlockNotFound = errors.New("weak subjectivity root not found in db")
 	// errWSBlockNotFoundInEpoch is returned when a block is not found in the WS cache or DB within epoch.
 	errWSBlockNotFoundInEpoch = errors.New("weak subjectivity root not found in db within epoch")
+	// errNotDescendantOfFinalized is returned when a block is not a descendant of the finalized checkpoint
+	errNotDescendantOfFinalized = invalidBlock{errors.New("not descendant of finalized checkpoint")}
 )
 
 // An invalid block is the block that fails state transition based on the core protocol rules.

beacon-chain/blockchain/head.go

@@ -9,6 +9,7 @@ import (
 	"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/forkchoice"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
 	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/protoarray"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
@@ -107,16 +108,16 @@ func (s *Service) updateHead(ctx context.Context, balances []uint64) ([32]byte,
 
 // This saves head info to the local service cache, it also saves the
 // new head root to the DB.
-func (s *Service) saveHead(ctx context.Context, headRoot [32]byte, headBlock interfaces.SignedBeaconBlock, headState state.BeaconState) error {
+func (s *Service) saveHead(ctx context.Context, newHeadRoot [32]byte, headBlock interfaces.SignedBeaconBlock, headState state.BeaconState) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.saveHead")
 	defer span.End()
 
 	// Do nothing if head hasn't changed.
-	r, err := s.HeadRoot(ctx)
+	oldHeadroot, err := s.HeadRoot(ctx)
 	if err != nil {
 		return err
 	}
-	if headRoot == bytesutil.ToBytes32(r) {
+	if newHeadRoot == bytesutil.ToBytes32(oldHeadroot) {
 		return nil
 	}
 	if err := wrapper.BeaconBlockIsNil(headBlock); err != nil {
@@ -128,17 +129,19 @@ func (s *Service) saveHead(ctx context.Context, headRoot [32]byte, headBlock int
 
 	// If the head state is not available, just return nil.
 	// There's nothing to cache
-	if !s.cfg.BeaconDB.HasStateSummary(ctx, headRoot) {
+	if !s.cfg.BeaconDB.HasStateSummary(ctx, newHeadRoot) {
 		return nil
 	}
 
 	// A chain re-org occurred, so we fire an event notifying the rest of the services.
-	headSlot := s.HeadSlot()
-	newHeadSlot := headBlock.Block().Slot()
+	s.headLock.RLock()
 	oldHeadRoot := s.headRoot()
 	oldStateRoot := s.headBlock().Block().StateRoot()
+	s.headLock.RUnlock()
+	headSlot := s.HeadSlot()
+	newHeadSlot := headBlock.Block().Slot()
 	newStateRoot := headBlock.Block().StateRoot()
-	if bytesutil.ToBytes32(headBlock.Block().ParentRoot()) != bytesutil.ToBytes32(r) {
+	if bytesutil.ToBytes32(headBlock.Block().ParentRoot()) != bytesutil.ToBytes32(oldHeadroot) {
 		log.WithFields(logrus.Fields{
 			"newSlot": fmt.Sprintf("%d", newHeadSlot),
 			"oldSlot": fmt.Sprintf("%d", headSlot),
@@ -154,7 +157,7 @@ func (s *Service) saveHead(ctx context.Context, headRoot [32]byte, headBlock int
 				Slot:                newHeadSlot,
 				Depth:               absoluteSlotDifference,
 				OldHeadBlock:        oldHeadRoot[:],
-				NewHeadBlock:        headRoot[:],
+				NewHeadBlock:        newHeadRoot[:],
 				OldHeadState:        oldStateRoot,
 				NewHeadState:        newStateRoot,
 				Epoch:               slots.ToEpoch(newHeadSlot),
@@ -162,25 +165,24 @@ func (s *Service) saveHead(ctx context.Context, headRoot [32]byte, headBlock int
 			},
 		})
 
-		if err := s.saveOrphanedAtts(ctx, bytesutil.ToBytes32(r)); err != nil {
+		if err := s.saveOrphanedAtts(ctx, bytesutil.ToBytes32(oldHeadroot), newHeadRoot); err != nil {
 			return err
 		}
-
 		reorgCount.Inc()
 	}
 
 	// Cache the new head info.
-	s.setHead(headRoot, headBlock, headState)
+	s.setHead(newHeadRoot, headBlock, headState)
 
 	// Save the new head root to DB.
-	if err := s.cfg.BeaconDB.SaveHeadBlockRoot(ctx, headRoot); err != nil {
+	if err := s.cfg.BeaconDB.SaveHeadBlockRoot(ctx, newHeadRoot); err != nil {
 		return errors.Wrap(err, "could not save head root in DB")
 	}
 
 	// Forward an event capturing a new chain head over a common event feed
 	// done in a goroutine to avoid blocking the critical runtime main routine.
 	go func() {
-		if err := s.notifyNewHeadEvent(ctx, newHeadSlot, headState, newStateRoot, headRoot[:]); err != nil {
+		if err := s.notifyNewHeadEvent(ctx, newHeadSlot, headState, newStateRoot, newHeadRoot[:]); err != nil {
 			log.WithError(err).Error("Could not notify event feed of new chain head")
 		}
 	}()
@@ -353,35 +355,48 @@ func (s *Service) notifyNewHeadEvent(
 	return nil
 }
 
-// This saves the attestations inside the beacon block with respect to root `orphanedRoot` back into the
-// attestation pool. It also filters out the attestations that is one epoch older as a
-// defense so invalid attestations don't flow into the attestation pool.
-func (s *Service) saveOrphanedAtts(ctx context.Context, orphanedRoot [32]byte) error {
-	orphanedBlk, err := s.getBlock(ctx, orphanedRoot)
-	if err != nil {
+// This saves the attestations between `orphanedRoot` and the common ancestor root that is derived using `newHeadRoot`.
+// It also filters out the attestations that is one epoch older as a defense so invalid attestations don't flow into the attestation pool.
+func (s *Service) saveOrphanedAtts(ctx context.Context, orphanedRoot [32]byte, newHeadRoot [32]byte) error {
+	commonAncestorRoot, err := s.ForkChoicer().CommonAncestorRoot(ctx, newHeadRoot, orphanedRoot)
+	switch {
+	// Exit early if there's no common ancestor as there would be nothing to save.
+	case errors.Is(err, forkchoice.ErrUnknownCommonAncestor):
+		return nil
+	case err != nil:
 		return err
 	}
-
-	if orphanedBlk == nil || orphanedBlk.IsNil() {
-		return errors.New("orphaned block can't be nil")
-	}
-
-	for _, a := range orphanedBlk.Block().Body().Attestations() {
-		// Is the attestation one epoch older.
-		if a.Data.Slot+params.BeaconConfig().SlotsPerEpoch < s.CurrentSlot() {
-			continue
+	for orphanedRoot != commonAncestorRoot {
+		if ctx.Err() != nil {
+			return ctx.Err()
 		}
-		if helpers.IsAggregated(a) {
-			if err := s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
-				return err
-			}
-		} else {
-			if err := s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
-				return err
-			}
-		}
-		saveOrphanedAttCount.Inc()
-	}
 
+		orphanedBlk, err := s.getBlock(ctx, orphanedRoot)
+		if err != nil {
+			return err
+		}
+		// If the block is an epoch older, break out of the loop since we can't include atts anyway.
+		// This prevents stuck within this for loop longer than necessary.
+		if orphanedBlk.Block().Slot()+params.BeaconConfig().SlotsPerEpoch <= s.CurrentSlot() {
+			break
+		}
+		for _, a := range orphanedBlk.Block().Body().Attestations() {
+			// if the attestation is one epoch older, it wouldn't been useful to save it.
+			if a.Data.Slot+params.BeaconConfig().SlotsPerEpoch < s.CurrentSlot() {
+				continue
+			}
+			if helpers.IsAggregated(a) {
+				if err := s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
+					return err
+				}
+			} else {
+				if err := s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
+					return err
+				}
+			}
+			saveOrphanedAttCount.Inc()
+		}
+		orphanedRoot = bytesutil.ToBytes32(orphanedBlk.Block().ParentRoot())
+	}
 	return nil
 }

beacon-chain/blockchain/head_test.go

@@ -3,6 +3,7 @@ package blockchain
 import (
 	"bytes"
 	"context"
+	"sort"
 	"testing"
 	"time"
 
@@ -10,9 +11,11 @@ import (
 	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/doubly-linked-tree"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
+	"github.com/prysmaticlabs/prysm/config/features"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
+	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	ethpbv1 "github.com/prysmaticlabs/prysm/proto/eth/v1"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/testing/assert"
@@ -49,6 +52,8 @@ func TestSaveHead_Different(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(context.Background(), oldBlock))
 	oldRoot, err := oldBlock.Block().HashTreeRoot()
 	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertOptimisticBlock(
+		ctx, oldBlock.Block().Slot(), oldRoot, bytesutil.ToBytes32(oldBlock.Block().ParentRoot()), [32]byte{}, 0, 0))
 	service.head = &head{
 		slot:  0,
 		root:  oldRoot,
@@ -64,6 +69,8 @@ func TestSaveHead_Different(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(context.Background(), wsb))
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertOptimisticBlock(
+		ctx, wsb.Block().Slot(), newRoot, bytesutil.ToBytes32(wsb.Block().ParentRoot()), [32]byte{}, 0, 0))
 	headState, err := util.NewBeaconState()
 	require.NoError(t, err)
 	require.NoError(t, headState.SetSlot(1))
@@ -93,6 +100,8 @@ func TestSaveHead_Different_Reorg(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(context.Background(), oldBlock))
 	oldRoot, err := oldBlock.Block().HashTreeRoot()
 	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertOptimisticBlock(
+		ctx, oldBlock.Block().Slot(), oldRoot, bytesutil.ToBytes32(oldBlock.Block().ParentRoot()), [32]byte{}, 0, 0))
 	service.head = &head{
 		slot:  0,
 		root:  oldRoot,
@@ -110,6 +119,8 @@ func TestSaveHead_Different_Reorg(t *testing.T) {
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(context.Background(), wsb))
 	newRoot, err := newHeadBlock.HashTreeRoot()
 	require.NoError(t, err)
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertOptimisticBlock(
+		ctx, wsb.Block().Slot(), newRoot, bytesutil.ToBytes32(wsb.Block().ParentRoot()), [32]byte{}, 0, 0))
 	headState, err := util.NewBeaconState()
 	require.NoError(t, err)
 	require.NoError(t, headState.SetSlot(1))
@@ -229,50 +240,355 @@ func Test_notifyNewHeadEvent(t *testing.T) {
 	})
 }
 
-func TestSaveOrphanedAtts(t *testing.T) {
-	genesis, keys := util.DeterministicGenesisState(t, 64)
-	b, err := util.GenerateFullBlock(genesis, keys, util.DefaultBlockGenConfig(), 1)
-	assert.NoError(t, err)
-	r, err := b.Block.HashTreeRoot()
-	require.NoError(t, err)
-
+func TestSaveOrphanedAtts_NoCommonAncestor(t *testing.T) {
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.genesisTime = time.Now()
+	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
 
-	wsb, err := wrapper.WrappedSignedBeaconBlock(b)
+	// Chain setup
+	// 0 -- 1 -- 2 -- 3
+	//    -4
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
+	assert.NoError(t, err)
+	b, err := wrapper.WrappedSignedBeaconBlock(blkG)
+	assert.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, b))
+	rG, err := blkG.Block.HashTreeRoot()
 	require.NoError(t, err)
-	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))
-	require.NoError(t, service.saveOrphanedAtts(ctx, r))
 
-	require.Equal(t, len(b.Block.Body.Attestations), service.cfg.AttPool.AggregatedAttestationCount())
-	savedAtts := service.cfg.AttPool.AggregatedAttestations()
-	atts := b.Block.Body.Attestations
-	require.DeepSSZEqual(t, atts, savedAtts)
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk3, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 3)
+	assert.NoError(t, err)
+	blk3.Block.ParentRoot = r2[:]
+	r3, err := blk3.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlock()
+	blk4.Block.Slot = 4
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk3, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		require.NoError(t, service.ForkChoicer().InsertOptimisticBlock(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, 0, 0))
+		b, err := wrapper.WrappedSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		require.NoError(t, beaconDB.SaveBlock(ctx, b))
+	}
+
+	require.NoError(t, service.saveOrphanedAtts(ctx, r3, r4))
+	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
+}
+
+func TestSaveOrphanedAtts(t *testing.T) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	service := setupBeaconChain(t, beaconDB)
+	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+
+	// Chain setup
+	// 0 -- 1 -- 2 -- 3
+	//  \-4
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
+	assert.NoError(t, err)
+	b, err := wrapper.WrappedSignedBeaconBlock(blkG)
+	assert.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, b))
+	rG, err := blkG.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk3, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 3)
+	assert.NoError(t, err)
+	blk3.Block.ParentRoot = r2[:]
+	r3, err := blk3.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlock()
+	blk4.Block.Slot = 4
+	blk4.Block.ParentRoot = rG[:]
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk3, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		require.NoError(t, service.ForkChoicer().InsertOptimisticBlock(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, 0, 0))
+		b, err := wrapper.WrappedSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		require.NoError(t, beaconDB.SaveBlock(ctx, b))
+	}
+
+	require.NoError(t, service.saveOrphanedAtts(ctx, r3, r4))
+	require.Equal(t, 3, service.cfg.AttPool.AggregatedAttestationCount())
+	wantAtts := []*ethpb.Attestation{
+		blk3.Block.Body.Attestations[0],
+		blk2.Block.Body.Attestations[0],
+		blk1.Block.Body.Attestations[0],
+	}
+	atts := service.cfg.AttPool.AggregatedAttestations()
+	sort.Slice(atts, func(i, j int) bool {
+		return atts[i].Data.Slot > atts[j].Data.Slot
+	})
+	require.DeepEqual(t, wantAtts, atts)
 }
 
 func TestSaveOrphanedAtts_CanFilter(t *testing.T) {
-	genesis, keys := util.DeterministicGenesisState(t, 64)
-	b, err := util.GenerateFullBlock(genesis, keys, util.DefaultBlockGenConfig(), 1)
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	service := setupBeaconChain(t, beaconDB)
+	service.genesisTime = time.Now().Add(time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch+2)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+
+	// Chain setup
+	// 0 -- 1 -- 2
+	//  \-4
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
 	assert.NoError(t, err)
-	r, err := b.Block.HashTreeRoot()
+	b, err := wrapper.WrappedSignedBeaconBlock(blkG)
+	assert.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, b))
+	rG, err := blkG.Block.HashTreeRoot()
 	require.NoError(t, err)
 
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlock()
+	blk4.Block.Slot = 4
+	blk4.Block.ParentRoot = rG[:]
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		require.NoError(t, service.ForkChoicer().InsertOptimisticBlock(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, 0, 0))
+		b, err := wrapper.WrappedSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		require.NoError(t, beaconDB.SaveBlock(ctx, b))
+	}
+
+	require.NoError(t, service.saveOrphanedAtts(ctx, r2, r4))
+	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
+}
+
+func TestSaveOrphanedAtts_NoCommonAncestor_DoublyLinkedTrie(t *testing.T) {
+	resetCfg := features.InitWithReset(&features.Flags{
+		EnableForkChoiceDoublyLinkedTree: true,
+	})
+	defer resetCfg()
+
 	ctx := context.Background()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.genesisTime = time.Now().Add(time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch+1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
 
-	wsb, err := wrapper.WrappedSignedBeaconBlock(b)
+	// Chain setup
+	// 0 -- 1 -- 2 -- 3
+	//    -4
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
+	assert.NoError(t, err)
+	b, err := wrapper.WrappedSignedBeaconBlock(blkG)
+	assert.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, b))
+	rG, err := blkG.Block.HashTreeRoot()
 	require.NoError(t, err)
-	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))
-	require.NoError(t, service.saveOrphanedAtts(ctx, r))
 
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk3, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 3)
+	assert.NoError(t, err)
+	blk3.Block.ParentRoot = r2[:]
+	r3, err := blk3.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlock()
+	blk4.Block.Slot = 4
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk3, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		require.NoError(t, service.ForkChoicer().InsertOptimisticBlock(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, 0, 0))
+		b, err := wrapper.WrappedSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		require.NoError(t, beaconDB.SaveBlock(ctx, b))
+	}
+
+	require.NoError(t, service.saveOrphanedAtts(ctx, r3, r4))
+	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
+}
+
+func TestSaveOrphanedAtts_DoublyLinkedTrie(t *testing.T) {
+	resetCfg := features.InitWithReset(&features.Flags{
+		EnableForkChoiceDoublyLinkedTree: true,
+	})
+	defer resetCfg()
+
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	service := setupBeaconChain(t, beaconDB)
+	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+
+	// Chain setup
+	// 0 -- 1 -- 2 -- 3
+	//  \-4
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
+	assert.NoError(t, err)
+	b, err := wrapper.WrappedSignedBeaconBlock(blkG)
+	assert.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, b))
+	rG, err := blkG.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk3, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 3)
+	assert.NoError(t, err)
+	blk3.Block.ParentRoot = r2[:]
+	r3, err := blk3.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlock()
+	blk4.Block.Slot = 4
+	blk4.Block.ParentRoot = rG[:]
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk3, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		require.NoError(t, service.ForkChoicer().InsertOptimisticBlock(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, 0, 0))
+		b, err := wrapper.WrappedSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		require.NoError(t, beaconDB.SaveBlock(ctx, b))
+	}
+
+	require.NoError(t, service.saveOrphanedAtts(ctx, r3, r4))
+	require.Equal(t, 3, service.cfg.AttPool.AggregatedAttestationCount())
+	wantAtts := []*ethpb.Attestation{
+		blk3.Block.Body.Attestations[0],
+		blk2.Block.Body.Attestations[0],
+		blk1.Block.Body.Attestations[0],
+	}
+	atts := service.cfg.AttPool.AggregatedAttestations()
+	sort.Slice(atts, func(i, j int) bool {
+		return atts[i].Data.Slot > atts[j].Data.Slot
+	})
+	require.DeepEqual(t, wantAtts, atts)
+}
+
+func TestSaveOrphanedAtts_CanFilter_DoublyLinkedTrie(t *testing.T) {
+	resetCfg := features.InitWithReset(&features.Flags{
+		EnableForkChoiceDoublyLinkedTree: true,
+	})
+	defer resetCfg()
+
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+	service := setupBeaconChain(t, beaconDB)
+	service.genesisTime = time.Now().Add(time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch+2)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+
+	// Chain setup
+	// 0 -- 1 -- 2
+	//  \-4
+	st, keys := util.DeterministicGenesisState(t, 64)
+	blkG, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 0)
+	assert.NoError(t, err)
+	b, err := wrapper.WrappedSignedBeaconBlock(blkG)
+	assert.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, b))
+	rG, err := blkG.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk1, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 1)
+	assert.NoError(t, err)
+	blk1.Block.ParentRoot = rG[:]
+	r1, err := blk1.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk2, err := util.GenerateFullBlock(st, keys, util.DefaultBlockGenConfig(), 2)
+	assert.NoError(t, err)
+	blk2.Block.ParentRoot = r1[:]
+	r2, err := blk2.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	blk4 := util.NewBeaconBlock()
+	blk4.Block.Slot = 4
+	blk4.Block.ParentRoot = rG[:]
+	r4, err := blk4.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	for _, blk := range []*ethpb.SignedBeaconBlock{blkG, blk1, blk2, blk4} {
+		r, err := blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+		require.NoError(t, service.ForkChoicer().InsertOptimisticBlock(ctx, blk.Block.Slot, r, bytesutil.ToBytes32(blk.Block.ParentRoot), [32]byte{}, 0, 0))
+		b, err := wrapper.WrappedSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		require.NoError(t, beaconDB.SaveBlock(ctx, b))
+	}
+
+	require.NoError(t, service.saveOrphanedAtts(ctx, r2, r4))
 	require.Equal(t, 0, service.cfg.AttPool.AggregatedAttestationCount())
-	savedAtts := service.cfg.AttPool.AggregatedAttestations()
-	atts := b.Block.Body.Attestations
-	require.DeepNotSSZEqual(t, atts, savedAtts)
 }
 
 func TestUpdateHead_noSavedChanges(t *testing.T) {

beacon-chain/blockchain/log.go

@@ -60,27 +60,23 @@ func logBlockSyncStatus(block interfaces.BeaconBlock, blockRoot [32]byte, justif
 		return err
 	}
 	level := log.Logger.GetLevel()
+
+	log = log.WithField("slot", block.Slot())
 	if level >= logrus.DebugLevel {
-		log.WithFields(logrus.Fields{
-			"slot":                      block.Slot(),
-			"slotInEpoch":               block.Slot() % params.BeaconConfig().SlotsPerEpoch,
-			"block":                     fmt.Sprintf("0x%s...", hex.EncodeToString(blockRoot[:])[:8]),
-			"epoch":                     slots.ToEpoch(block.Slot()),
-			"justifiedEpoch":            justified.Epoch,
-			"justifiedRoot":             fmt.Sprintf("0x%s...", hex.EncodeToString(justified.Root)[:8]),
-			"finalizedEpoch":            finalized.Epoch,
-			"finalizedRoot":             fmt.Sprintf("0x%s...", hex.EncodeToString(finalized.Root)[:8]),
-			"parentRoot":                fmt.Sprintf("0x%s...", hex.EncodeToString(block.ParentRoot())[:8]),
-			"version":                   version.String(block.Version()),
-			"sinceSlotStartTime":        prysmTime.Now().Sub(startTime),
-			"chainServiceProcessedTime": prysmTime.Now().Sub(receivedTime),
-		}).Debug("Synced new block")
-	} else {
-		log.WithFields(logrus.Fields{
-			"slot":  block.Slot(),
-			"block": fmt.Sprintf("0x%s...", hex.EncodeToString(blockRoot[:])[:8]),
-			"epoch": slots.ToEpoch(block.Slot()),
-		}).Info("Synced new block")
+		log = log.WithField("slotInEpoch", block.Slot()%params.BeaconConfig().SlotsPerEpoch)
+		log = log.WithField("justifiedEpoch", justified.Epoch)
+		log = log.WithField("justifiedRoot", fmt.Sprintf("0x%s...", hex.EncodeToString(justified.Root)[:8]))
+		log = log.WithField("parentRoot", fmt.Sprintf("0x%s...", hex.EncodeToString(block.ParentRoot())[:8]))
+		log = log.WithField("version", version.String(block.Version()))
+		log = log.WithField("sinceSlotStartTime", prysmTime.Now().Sub(startTime))
+		log = log.WithField("chainServiceProcessedTime", prysmTime.Now().Sub(receivedTime))
 	}
+
+	log.WithFields(logrus.Fields{
+		"block":          fmt.Sprintf("0x%s...", hex.EncodeToString(blockRoot[:])[:8]),
+		"epoch":          slots.ToEpoch(block.Slot()),
+		"finalizedEpoch": finalized.Epoch,
+		"finalizedRoot":  fmt.Sprintf("0x%s...", hex.EncodeToString(finalized.Root)[:8]),
+	}).Info("Synced new block")
 	return nil
 }

beacon-chain/blockchain/process_block.go

@@ -16,6 +16,7 @@ import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/features"
 	"github.com/prysmaticlabs/prysm/config/params"
+	"github.com/prysmaticlabs/prysm/consensus-types/forks/bellatrix"
 	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
@@ -117,7 +118,7 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlo
 	}
 	isValidPayload, err := s.notifyNewPayload(ctx, postStateVersion, postStateHeader, signed)
 	if err != nil {
-		return errors.Wrap(err, "could not verify new payload")
+		return fmt.Errorf("could not verify new payload: %v", err)
 	}
 	if isValidPayload {
 		if err := s.validateMergeTransitionBlock(ctx, preStateVersion, preStateHeader, signed); err != nil {
@@ -130,7 +131,7 @@ func (s *Service) onBlock(ctx context.Context, signed interfaces.SignedBeaconBlo
 	if err := s.insertBlockAndAttestationsToForkChoiceStore(ctx, signed.Block(), blockRoot, postState); err != nil {
 		return errors.Wrapf(err, "could not insert block %d to fork choice store", signed.Block().Slot())
 	}
-	s.insertSlashingsToForkChoiceStore(ctx, signed.Block().Body().AttesterSlashings())
+	s.InsertSlashingsToForkChoiceStore(ctx, signed.Block().Body().AttesterSlashings())
 	if isValidPayload {
 		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, blockRoot); err != nil {
 			return errors.Wrap(err, "could not set optimistic block to valid")
@@ -334,33 +335,33 @@ func getStateVersionAndPayload(st state.BeaconState) (int, *ethpb.ExecutionPaylo
 }
 
 func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeaconBlock,
-	blockRoots [][32]byte) ([]*ethpb.Checkpoint, []*ethpb.Checkpoint, error) {
+	blockRoots [][32]byte) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.onBlockBatch")
 	defer span.End()
 
 	if len(blks) == 0 || len(blockRoots) == 0 {
-		return nil, nil, errors.New("no blocks provided")
+		return errors.New("no blocks provided")
 	}
 
 	if len(blks) != len(blockRoots) {
-		return nil, nil, errWrongBlockCount
+		return errWrongBlockCount
 	}
 
 	if err := wrapper.BeaconBlockIsNil(blks[0]); err != nil {
-		return nil, nil, invalidBlock{err}
+		return invalidBlock{err}
 	}
 	b := blks[0].Block()
 
 	// Retrieve incoming block's pre state.
 	if err := s.verifyBlkPreState(ctx, b); err != nil {
-		return nil, nil, err
+		return err
 	}
 	preState, err := s.cfg.StateGen.StateByRootInitialSync(ctx, bytesutil.ToBytes32(b.ParentRoot()))
 	if err != nil {
-		return nil, nil, err
+		return err
 	}
 	if preState == nil || preState.IsNil() {
-		return nil, nil, fmt.Errorf("nil pre state for slot %d", b.Slot())
+		return fmt.Errorf("nil pre state for slot %d", b.Slot())
 	}
 
 	jCheckpoints := make([]*ethpb.Checkpoint, len(blks))
@@ -381,7 +382,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 	for i, b := range blks {
 		v, h, err := getStateVersionAndPayload(preState)
 		if err != nil {
-			return nil, nil, err
+			return err
 		}
 		preVersionAndHeaders[i] = &versionAndHeader{
 			version: v,
@@ -390,7 +391,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 
 		set, preState, err = transition.ExecuteStateTransitionNoVerifyAnySig(ctx, preState, b)
 		if err != nil {
-			return nil, nil, invalidBlock{err}
+			return invalidBlock{err}
 		}
 		// Save potential boundary states.
 		if slots.IsEpochStart(preState.Slot()) {
@@ -401,7 +402,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 
 		v, h, err = getStateVersionAndPayload(preState)
 		if err != nil {
-			return nil, nil, err
+			return err
 		}
 		postVersionAndHeaders[i] = &versionAndHeader{
 			version: v,
@@ -411,10 +412,10 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 	}
 	verify, err := sigSet.Verify()
 	if err != nil {
-		return nil, nil, invalidBlock{err}
+		return invalidBlock{err}
 	}
 	if !verify {
-		return nil, nil, errors.New("batch block signature verification failed")
+		return errors.New("batch block signature verification failed")
 	}
 
 	// blocks have been verified, add them to forkchoice and call the engine
@@ -423,40 +424,40 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 			postVersionAndHeaders[i].version,
 			postVersionAndHeaders[i].header, b)
 		if err != nil {
-			return nil, nil, err
+			return err
 		}
 		if isValidPayload {
 			if err := s.validateMergeTransitionBlock(ctx, preVersionAndHeaders[i].version,
 				preVersionAndHeaders[i].header, b); err != nil {
-				return nil, nil, err
+				return err
 			}
 		}
 
 		if err := s.insertBlockToForkChoiceStore(ctx, b.Block(), blockRoots[i], fCheckpoints[i], jCheckpoints[i]); err != nil {
-			return nil, nil, err
+			return err
 		}
 		if isValidPayload {
 			if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, blockRoots[i]); err != nil {
-				return nil, nil, errors.Wrap(err, "could not set optimistic block to valid")
+				return errors.Wrap(err, "could not set optimistic block to valid")
 			}
 		}
 		s.saveInitSyncBlock(blockRoots[i], b)
 		if err = s.handleBlockAfterBatchVerify(ctx, b, blockRoots[i], fCheckpoints[i], jCheckpoints[i]); err != nil {
 			tracing.AnnotateError(span, err)
-			return nil, nil, err
+			return err
 		}
 	}
 
 	for r, st := range boundaries {
 		if err := s.cfg.StateGen.SaveState(ctx, r, st); err != nil {
-			return nil, nil, err
+			return err
 		}
 	}
 	// Also saves the last post state which to be used as pre state for the next batch.
 	lastB := blks[len(blks)-1]
 	lastBR := blockRoots[len(blockRoots)-1]
 	if err := s.cfg.StateGen.SaveState(ctx, lastBR, preState); err != nil {
-		return nil, nil, err
+		return err
 	}
 	arg := &notifyForkchoiceUpdateArg{
 		headState: preState,
@@ -464,12 +465,9 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.SignedBeac
 		headBlock: lastB.Block(),
 	}
 	if _, err := s.notifyForkchoiceUpdate(ctx, arg); err != nil {
-		return nil, nil, err
+		return err
 	}
-	if err := s.saveHeadNoDB(ctx, lastB, lastBR, preState); err != nil {
-		return nil, nil, err
-	}
-	return fCheckpoints, jCheckpoints, nil
+	return s.saveHeadNoDB(ctx, lastB, lastBR, preState)
 }
 
 // handles a block after the block's batch has been verified, where we can save blocks
@@ -520,6 +518,12 @@ func (s *Service) handleBlockAfterBatchVerify(ctx context.Context, signed interf
 			return err
 		}
 		s.store.SetFinalizedCheckptAndPayloadHash(fCheckpoint, h)
+		if err := s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(fCheckpoint); err != nil {
+			return err
+		}
+		if err := s.cfg.ForkChoiceStore.Prune(ctx, bytesutil.ToBytes32(fCheckpoint.Root)); err != nil {
+			return errors.Wrap(err, "could not prune proto array fork choice nodes")
+		}
 	}
 	return nil
 }
@@ -536,16 +540,20 @@ func (s *Service) handleEpochBoundary(ctx context.Context, postState state.Beaco
 			return err
 		}
 		// Update caches for the next epoch at epoch boundary slot - 1.
-		if err := helpers.UpdateCommitteeCache(copied, coreTime.CurrentEpoch(copied)); err != nil {
+		if err := helpers.UpdateCommitteeCache(ctx, copied, coreTime.CurrentEpoch(copied)); err != nil {
 			return err
 		}
 		if err := helpers.UpdateProposerIndicesInCache(ctx, copied); err != nil {
 			return err
 		}
 	} else if postState.Slot() >= s.nextEpochBoundarySlot {
-		if err := reportEpochMetrics(ctx, postState, s.head.state); err != nil {
+		s.headLock.RLock()
+		st := s.head.state
+		s.headLock.RUnlock()
+		if err := reportEpochMetrics(ctx, postState, st); err != nil {
 			return err
 		}
+
 		var err error
 		s.nextEpochBoundarySlot, err = slots.EpochStart(coreTime.NextEpoch(postState))
 		if err != nil {
@@ -554,7 +562,7 @@ func (s *Service) handleEpochBoundary(ctx context.Context, postState state.Beaco
 
 		// 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, coreTime.CurrentEpoch(postState)); err != nil {
+		if err := helpers.UpdateCommitteeCache(ctx, postState, coreTime.CurrentEpoch(postState)); err != nil {
 			return err
 		}
 		if err := helpers.UpdateProposerIndicesInCache(ctx, postState); err != nil {
@@ -599,7 +607,7 @@ func (s *Service) insertBlockToForkChoiceStore(ctx context.Context, blk interfac
 	}
 	// Feed in block to fork choice store.
 
-	payloadHash, err := getBlockPayloadHash(blk)
+	payloadHash, err := blocks.GetBlockPayloadHash(blk)
 	if err != nil {
 		return err
 	}
@@ -611,7 +619,7 @@ func (s *Service) insertBlockToForkChoiceStore(ctx context.Context, blk interfac
 
 // Inserts attester slashing indices to fork choice store.
 // To call this function, it's caller's responsibility to ensure the slashing object is valid.
-func (s *Service) insertSlashingsToForkChoiceStore(ctx context.Context, slashings []*ethpb.AttesterSlashing) {
+func (s *Service) InsertSlashingsToForkChoiceStore(ctx context.Context, slashings []*ethpb.AttesterSlashing) {
 	for _, slashing := range slashings {
 		indices := blocks.SlashableAttesterIndices(slashing)
 		for _, index := range indices {
@@ -620,18 +628,6 @@ func (s *Service) insertSlashingsToForkChoiceStore(ctx context.Context, slashing
 	}
 }
 
-func getBlockPayloadHash(blk interfaces.BeaconBlock) ([32]byte, error) {
-	payloadHash := [32]byte{}
-	if blocks.IsPreBellatrixVersion(blk.Version()) {
-		return payloadHash, nil
-	}
-	payload, err := blk.Body().ExecutionPayload()
-	if err != nil {
-		return payloadHash, err
-	}
-	return bytesutil.ToBytes32(payload.BlockHash), nil
-}
-
 // This saves post state info to DB or cache. This also saves post state info to fork choice store.
 // Post state info consists of processed block and state. Do not call this method unless the block and state are verified.
 func (s *Service) savePostStateInfo(ctx context.Context, r [32]byte, b interfaces.SignedBeaconBlock, st state.BeaconState) error {
@@ -688,7 +684,7 @@ func (s *Service) validateMergeTransitionBlock(ctx context.Context, stateVersion
 	if err != nil {
 		return invalidBlock{err}
 	}
-	if blocks.IsEmptyPayload(payload) {
+	if bellatrix.IsEmptyPayload(payload) {
 		return nil
 	}
 

beacon-chain/blockchain/process_block_helpers.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
@@ -241,8 +242,7 @@ func (s *Service) updateJustifiedInitSync(ctx context.Context, cp *ethpb.Checkpo
 		return err
 	}
 	s.store.SetJustifiedCheckptAndPayloadHash(cp, h)
-
-	return nil
+	return s.cfg.ForkChoiceStore.UpdateJustifiedCheckpoint(cp)
 }
 
 func (s *Service) updateFinalized(ctx context.Context, cp *ethpb.Checkpoint) error {
@@ -346,11 +346,8 @@ func (s *Service) ancestorByDB(ctx context.Context, r [32]byte, slot types.Slot)
 // This is useful for block tree visualizer and additional vote accounting.
 func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, blk interfaces.BeaconBlock,
 	fCheckpoint, jCheckpoint *ethpb.Checkpoint) error {
-	pendingNodes := make([]interfaces.BeaconBlock, 0)
-	pendingRoots := make([][32]byte, 0)
+	pendingNodes := make([]*forkchoicetypes.BlockAndCheckpoints, 0)
 
-	parentRoot := bytesutil.ToBytes32(blk.ParentRoot())
-	slot := blk.Slot()
 	// Fork choice only matters from last finalized slot.
 	finalized, err := s.store.FinalizedCheckpt()
 	if err != nil {
@@ -360,39 +357,31 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, blk interfa
 	if err != nil {
 		return err
 	}
-	higherThanFinalized := slot > fSlot
+	pendingNodes = append(pendingNodes, &forkchoicetypes.BlockAndCheckpoints{Block: blk,
+		JustifiedEpoch: jCheckpoint.Epoch, FinalizedEpoch: fCheckpoint.Epoch})
 	// As long as parent node is not in fork choice store, and parent node is in DB.
-	for !s.cfg.ForkChoiceStore.HasNode(parentRoot) && s.cfg.BeaconDB.HasBlock(ctx, parentRoot) && higherThanFinalized {
-		b, err := s.getBlock(ctx, parentRoot)
+	root := bytesutil.ToBytes32(blk.ParentRoot())
+	for !s.cfg.ForkChoiceStore.HasNode(root) && s.cfg.BeaconDB.HasBlock(ctx, root) {
+		b, err := s.getBlock(ctx, root)
 		if err != nil {
 			return err
 		}
-
-		pendingNodes = append(pendingNodes, b.Block())
-		copiedRoot := parentRoot
-		pendingRoots = append(pendingRoots, copiedRoot)
-		parentRoot = bytesutil.ToBytes32(b.Block().ParentRoot())
-		slot = b.Block().Slot()
-		higherThanFinalized = slot > fSlot
-	}
-
-	// Insert parent nodes to fork choice store in reverse order.
-	// Lower slots should be at the end of the list.
-	for i := len(pendingNodes) - 1; i >= 0; i-- {
-		b := pendingNodes[i]
-		r := pendingRoots[i]
-		payloadHash, err := getBlockPayloadHash(blk)
-		if err != nil {
-			return err
-		}
-		if err := s.cfg.ForkChoiceStore.InsertOptimisticBlock(ctx,
-			b.Slot(), r, bytesutil.ToBytes32(b.ParentRoot()), payloadHash,
-			jCheckpoint.Epoch,
-			fCheckpoint.Epoch); err != nil {
-			return errors.Wrap(err, "could not process block for proto array fork choice")
+		if b.Block().Slot() <= fSlot {
+			break
 		}
+		root = bytesutil.ToBytes32(b.Block().ParentRoot())
+		args := &forkchoicetypes.BlockAndCheckpoints{Block: b.Block(),
+			JustifiedEpoch: jCheckpoint.Epoch,
+			FinalizedEpoch: fCheckpoint.Epoch}
+		pendingNodes = append(pendingNodes, args)
 	}
-	return nil
+	if len(pendingNodes) == 1 {
+		return nil
+	}
+	if root != s.ensureRootNotZeros(bytesutil.ToBytes32(finalized.Root)) {
+		return errNotDescendantOfFinalized
+	}
+	return s.cfg.ForkChoiceStore.InsertOptimisticChain(ctx, pendingNodes)
 }
 
 // inserts finalized deposits into our finalized deposit trie.

beacon-chain/blockchain/process_block_test.go

@@ -305,7 +305,7 @@ func TestStore_OnBlockBatch_ProtoArray(t *testing.T) {
 	var blks []interfaces.SignedBeaconBlock
 	var blkRoots [][32]byte
 	var firstState state.BeaconState
-	for i := 1; i < 10; i++ {
+	for i := 1; i < 97; i++ {
 		b, err := util.GenerateFullBlock(bState, keys, util.DefaultBlockGenConfig(), types.Slot(i))
 		require.NoError(t, err)
 		wsb, err := wrapper.WrappedSignedBeaconBlock(b)
@@ -331,10 +331,15 @@ func TestStore_OnBlockBatch_ProtoArray(t *testing.T) {
 	rBlock.Block.ParentRoot = gRoot[:]
 	require.NoError(t, beaconDB.SaveBlock(context.Background(), blks[0]))
 	require.NoError(t, service.cfg.StateGen.SaveState(ctx, blkRoots[0], firstState))
-	_, _, err = service.onBlockBatch(ctx, blks, blkRoots[1:])
+	err = service.onBlockBatch(ctx, blks, blkRoots[1:])
 	require.ErrorIs(t, errWrongBlockCount, err)
-	_, _, err = service.onBlockBatch(ctx, blks[1:], blkRoots[1:])
+	err = service.onBlockBatch(ctx, blks[1:], blkRoots[1:])
 	require.NoError(t, err)
+	jcp, err := service.store.JustifiedCheckpt()
+	require.NoError(t, err)
+	jroot := bytesutil.ToBytes32(jcp.Root)
+	require.Equal(t, blkRoots[63], jroot)
+	require.Equal(t, types.Epoch(2), service.cfg.ForkChoiceStore.JustifiedEpoch())
 }
 
 func TestStore_OnBlockBatch_DoublyLinkedTree(t *testing.T) {
@@ -370,7 +375,7 @@ func TestStore_OnBlockBatch_DoublyLinkedTree(t *testing.T) {
 	var blks []interfaces.SignedBeaconBlock
 	var blkRoots [][32]byte
 	var firstState state.BeaconState
-	for i := 1; i < 10; i++ {
+	for i := 1; i < 97; i++ {
 		b, err := util.GenerateFullBlock(bState, keys, util.DefaultBlockGenConfig(), types.Slot(i))
 		require.NoError(t, err)
 		wsb, err = wrapper.WrappedSignedBeaconBlock(b)
@@ -396,10 +401,15 @@ func TestStore_OnBlockBatch_DoublyLinkedTree(t *testing.T) {
 	rBlock.Block.ParentRoot = gRoot[:]
 	require.NoError(t, beaconDB.SaveBlock(context.Background(), blks[0]))
 	require.NoError(t, service.cfg.StateGen.SaveState(ctx, blkRoots[0], firstState))
-	_, _, err = service.onBlockBatch(ctx, blks, blkRoots[1:])
+	err = service.onBlockBatch(ctx, blks, blkRoots[1:])
 	require.ErrorIs(t, errWrongBlockCount, err)
-	_, _, err = service.onBlockBatch(ctx, blks[1:], blkRoots[1:])
+	err = service.onBlockBatch(ctx, blks[1:], blkRoots[1:])
 	require.NoError(t, err)
+	jcp, err := service.store.JustifiedCheckpt()
+	require.NoError(t, err)
+	jroot := bytesutil.ToBytes32(jcp.Root)
+	require.Equal(t, blkRoots[63], jroot)
+	require.Equal(t, types.Epoch(2), service.cfg.ForkChoiceStore.JustifiedEpoch())
 }
 
 func TestStore_OnBlockBatch_NotifyNewPayload(t *testing.T) {
@@ -452,10 +462,8 @@ func TestStore_OnBlockBatch_NotifyNewPayload(t *testing.T) {
 	rBlock.Block.ParentRoot = gRoot[:]
 	require.NoError(t, beaconDB.SaveBlock(context.Background(), blks[0]))
 	require.NoError(t, service.cfg.StateGen.SaveState(ctx, blkRoots[0], firstState))
-	cp1, cp2, err := service.onBlockBatch(ctx, blks[1:], blkRoots[1:])
+	err = service.onBlockBatch(ctx, blks[1:], blkRoots[1:])
 	require.NoError(t, err)
-	require.Equal(t, blkCount-1, len(cp1))
-	require.Equal(t, blkCount-1, len(cp2))
 }
 
 func TestRemoveStateSinceLastFinalized_EmptyStartSlot(t *testing.T) {
@@ -732,7 +740,6 @@ func TestFillForkChoiceMissingBlocks_CanSave_ProtoArray(t *testing.T) {
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
 	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
-	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: make([]byte, 32)}, [32]byte{})
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -755,12 +762,14 @@ func TestFillForkChoiceMissingBlocks_CanSave_ProtoArray(t *testing.T) {
 	wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
 
+	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: roots[0]}, [32]byte{})
 	err = service.fillInForkChoiceMissingBlocks(
 		context.Background(), wsb.Block(), beaconState.FinalizedCheckpoint(), beaconState.CurrentJustifiedCheckpoint())
 	require.NoError(t, err)
 
-	// 5 nodes from the block tree 1. B0 - B3 - B4 - B6 - B8
-	assert.Equal(t, 5, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	// 4 nodes from the block tree 1. B3 - B4 - B6 - B8
+	assert.Equal(t, 4, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(roots[3])), "Didn't save node")
 	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(roots[4])), "Didn't save node")
 	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(roots[6])), "Didn't save node")
 	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(roots[8])), "Didn't save node")
@@ -777,7 +786,6 @@ func TestFillForkChoiceMissingBlocks_CanSave_DoublyLinkedTree(t *testing.T) {
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
 	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
-	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: make([]byte, 32)}, [32]byte{})
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -801,12 +809,14 @@ func TestFillForkChoiceMissingBlocks_CanSave_DoublyLinkedTree(t *testing.T) {
 	wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
 
+	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: roots[0]}, [32]byte{})
 	err = service.fillInForkChoiceMissingBlocks(
 		context.Background(), wsb.Block(), beaconState.FinalizedCheckpoint(), beaconState.CurrentJustifiedCheckpoint())
 	require.NoError(t, err)
 
 	// 5 nodes from the block tree 1. B0 - B3 - B4 - B6 - B8
-	assert.Equal(t, 5, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	assert.Equal(t, 4, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(roots[3])), "Didn't save node")
 	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(roots[4])), "Didn't save node")
 	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(roots[6])), "Didn't save node")
 	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(roots[8])), "Didn't save node")
@@ -823,7 +833,6 @@ func TestFillForkChoiceMissingBlocks_RootsMatch_ProtoArray(t *testing.T) {
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
 	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
-	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: make([]byte, 32)}, [32]byte{})
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -847,14 +856,15 @@ func TestFillForkChoiceMissingBlocks_RootsMatch_ProtoArray(t *testing.T) {
 	wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
 
+	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: roots[0]}, [32]byte{})
 	err = service.fillInForkChoiceMissingBlocks(
 		context.Background(), wsb.Block(), beaconState.FinalizedCheckpoint(), beaconState.CurrentJustifiedCheckpoint())
 	require.NoError(t, err)
 
-	// 5 nodes from the block tree 1. B0 - B3 - B4 - B6 - B8
-	assert.Equal(t, 5, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	// 4 nodes from the block tree 1. B3 - B4 - B6 - B8
+	assert.Equal(t, 4, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
 	// Ensure all roots and their respective blocks exist.
-	wantedRoots := [][]byte{roots[0], roots[3], roots[4], roots[6], roots[8]}
+	wantedRoots := [][]byte{roots[3], roots[4], roots[6], roots[8]}
 	for i, rt := range wantedRoots {
 		assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(rt)), fmt.Sprintf("Didn't save node: %d", i))
 		assert.Equal(t, true, service.cfg.BeaconDB.HasBlock(context.Background(), bytesutil.ToBytes32(rt)))
@@ -872,7 +882,6 @@ func TestFillForkChoiceMissingBlocks_RootsMatch_DoublyLinkedTree(t *testing.T) {
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
 	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
-	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: make([]byte, 32)}, [32]byte{})
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -896,14 +905,15 @@ func TestFillForkChoiceMissingBlocks_RootsMatch_DoublyLinkedTree(t *testing.T) {
 	wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
 	require.NoError(t, err)
 
+	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: roots[0]}, [32]byte{})
 	err = service.fillInForkChoiceMissingBlocks(
 		context.Background(), wsb.Block(), beaconState.FinalizedCheckpoint(), beaconState.CurrentJustifiedCheckpoint())
 	require.NoError(t, err)
 
-	// 5 nodes from the block tree 1. B0 - B3 - B4 - B6 - B8
-	assert.Equal(t, 5, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	// 5 nodes from the block tree 1. B3 - B4 - B6 - B8
+	assert.Equal(t, 4, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
 	// Ensure all roots and their respective blocks exist.
-	wantedRoots := [][]byte{roots[0], roots[3], roots[4], roots[6], roots[8]}
+	wantedRoots := [][]byte{roots[3], roots[4], roots[6], roots[8]}
 	for i, rt := range wantedRoots {
 		assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(bytesutil.ToBytes32(rt)), fmt.Sprintf("Didn't save node: %d", i))
 		assert.Equal(t, true, service.cfg.BeaconDB.HasBlock(context.Background(), bytesutil.ToBytes32(rt)))
@@ -921,8 +931,6 @@ func TestFillForkChoiceMissingBlocks_FilterFinalized_ProtoArray(t *testing.T) {
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
 	service.cfg.ForkChoiceStore = protoarray.New(0, 0)
-	// Set finalized epoch to 1.
-	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Epoch: 1}, [32]byte{})
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -936,7 +944,7 @@ func TestFillForkChoiceMissingBlocks_FilterFinalized_ProtoArray(t *testing.T) {
 
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, st.Copy(), validGenesisRoot))
 
-	// Define a tree branch, slot 63 <- 64 <- 65
+	// Define a tree branch, slot 63 <- 64 <- 65 <- 66
 	b63 := util.NewBeaconBlock()
 	b63.Block.Slot = 63
 	wsb, err = wrapper.WrappedSignedBeaconBlock(b63)
@@ -955,20 +963,28 @@ func TestFillForkChoiceMissingBlocks_FilterFinalized_ProtoArray(t *testing.T) {
 	b65 := util.NewBeaconBlock()
 	b65.Block.Slot = 65
 	b65.Block.ParentRoot = r64[:]
+	r65, err := b65.Block.HashTreeRoot()
+	require.NoError(t, err)
 	wsb, err = wrapper.WrappedSignedBeaconBlock(b65)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))
+	b66 := util.NewBeaconBlock()
+	b66.Block.Slot = 66
+	b66.Block.ParentRoot = r65[:]
+	wsb, err = wrapper.WrappedSignedBeaconBlock(b66)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))
 
 	beaconState, _ := util.DeterministicGenesisState(t, 32)
+	// Set finalized epoch to 2.
+	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Epoch: 2, Root: r64[:]}, [32]byte{})
 	err = service.fillInForkChoiceMissingBlocks(
 		context.Background(), wsb.Block(), beaconState.FinalizedCheckpoint(), beaconState.CurrentJustifiedCheckpoint())
 	require.NoError(t, err)
 
-	// There should be 2 nodes, block 65 and block 64.
-	assert.Equal(t, 2, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
-
-	// Block with slot 63 should be in fork choice because it's less than finalized epoch 1.
-	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(r63), "Didn't save node")
+	// We should have saved 1 node: block 65
+	assert.Equal(t, 1, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(r65), "Didn't save node")
 }
 
 func TestFillForkChoiceMissingBlocks_FilterFinalized_DoublyLinkedTree(t *testing.T) {
@@ -982,8 +998,6 @@ func TestFillForkChoiceMissingBlocks_FilterFinalized_DoublyLinkedTree(t *testing
 	service, err := NewService(ctx, opts...)
 	require.NoError(t, err)
 	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
-	// Set finalized epoch to 1.
-	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Epoch: 1}, [32]byte{})
 
 	genesisStateRoot := [32]byte{}
 	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
@@ -1016,27 +1030,75 @@ func TestFillForkChoiceMissingBlocks_FilterFinalized_DoublyLinkedTree(t *testing
 	b65 := util.NewBeaconBlock()
 	b65.Block.Slot = 65
 	b65.Block.ParentRoot = r64[:]
+	r65, err := b65.Block.HashTreeRoot()
+	require.NoError(t, err)
 	wsb, err = wrapper.WrappedSignedBeaconBlock(b65)
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))
+	b66 := util.NewBeaconBlock()
+	b66.Block.Slot = 66
+	b66.Block.ParentRoot = r65[:]
+	wsb, err = wrapper.WrappedSignedBeaconBlock(b66)
+	require.NoError(t, err)
+	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb))
 
 	beaconState, _ := util.DeterministicGenesisState(t, 32)
+
+	// Set finalized epoch to 1.
+	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Epoch: 2, Root: r64[:]}, [32]byte{})
 	err = service.fillInForkChoiceMissingBlocks(
 		context.Background(), wsb.Block(), beaconState.FinalizedCheckpoint(), beaconState.CurrentJustifiedCheckpoint())
 	require.NoError(t, err)
 
-	// There should be 2 nodes, block 65 and block 64.
-	assert.Equal(t, 2, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	// There should be 1 node: block 65
+	assert.Equal(t, 1, service.cfg.ForkChoiceStore.NodeCount(), "Miss match nodes")
+	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(r65), "Didn't save node")
+}
 
-	// Block with slot 63 should be in fork choice because it's less than finalized epoch 1.
-	assert.Equal(t, true, service.cfg.ForkChoiceStore.HasNode(r63), "Didn't save node")
+func TestFillForkChoiceMissingBlocks_FinalizedSibling_DoublyLinkedTree(t *testing.T) {
+	ctx := context.Background()
+	beaconDB := testDB.SetupDB(t)
+
+	opts := []Option{
+		WithDatabase(beaconDB),
+		WithStateGen(stategen.New(beaconDB)),
+	}
+	service, err := NewService(ctx, opts...)
+	require.NoError(t, err)
+	service.cfg.ForkChoiceStore = doublylinkedtree.New(0, 0)
+
+	genesisStateRoot := [32]byte{}
+	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
+	wsb, err := wrapper.WrappedSignedBeaconBlock(genesis)
+	require.NoError(t, err)
+	require.NoError(t, beaconDB.SaveBlock(ctx, wsb))
+	validGenesisRoot, err := genesis.Block.HashTreeRoot()
+	require.NoError(t, err)
+	st, err := util.NewBeaconState()
+	require.NoError(t, err)
+
+	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, st.Copy(), validGenesisRoot))
+	roots, err := blockTree1(t, beaconDB, validGenesisRoot[:])
+	require.NoError(t, err)
+
+	beaconState, _ := util.DeterministicGenesisState(t, 32)
+	blk := util.NewBeaconBlock()
+	blk.Block.Slot = 9
+	blk.Block.ParentRoot = roots[8]
+
+	wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
+	require.NoError(t, err)
+
+	service.store.SetFinalizedCheckptAndPayloadHash(&ethpb.Checkpoint{Root: roots[1]}, [32]byte{})
+	err = service.fillInForkChoiceMissingBlocks(
+		context.Background(), wsb.Block(), beaconState.FinalizedCheckpoint(), beaconState.CurrentJustifiedCheckpoint())
+	require.ErrorIs(t, errNotDescendantOfFinalized, err)
 }
 
 // blockTree1 constructs the following tree:
 //    /- B1
 // B0           /- B5 - B7
 //    \- B3 - B4 - B6 - B8
-// (B1, and B3 are all from the same slots)
 func blockTree1(t *testing.T, beaconDB db.Database, genesisRoot []byte) ([][]byte, error) {
 	genesisRoot = bytesutil.PadTo(genesisRoot, 32)
 	b0 := util.NewBeaconBlock()
@@ -1965,7 +2027,7 @@ func TestService_insertSlashingsToForkChoiceStore(t *testing.T) {
 	b.Block.Body.AttesterSlashings = slashings
 	wb, err := wrapper.WrappedSignedBeaconBlock(b)
 	require.NoError(t, err)
-	service.insertSlashingsToForkChoiceStore(ctx, wb.Block().Body().AttesterSlashings())
+	service.InsertSlashingsToForkChoiceStore(ctx, wb.Block().Body().AttesterSlashings())
 }
 
 func TestOnBlock_ProcessBlocksParallel(t *testing.T) {

beacon-chain/blockchain/receive_attestation.go

@@ -164,21 +164,26 @@ func (s *Service) UpdateHead(ctx context.Context) error {
 	if err != nil {
 		log.WithError(err).Warn("Resolving fork due to new attestation")
 	}
+	s.headLock.RLock()
 	if s.headRoot() != newHeadRoot {
 		log.WithFields(logrus.Fields{
 			"oldHeadRoot": fmt.Sprintf("%#x", s.headRoot()),
 			"newHeadRoot": fmt.Sprintf("%#x", newHeadRoot),
 		}).Debug("Head changed due to attestations")
 	}
+	s.headLock.RUnlock()
 	s.notifyEngineIfChangedHead(ctx, newHeadRoot)
 	return nil
 }
 
 // This calls notify Forkchoice Update in the event that the head has changed
 func (s *Service) notifyEngineIfChangedHead(ctx context.Context, newHeadRoot [32]byte) {
+	s.headLock.RLock()
 	if newHeadRoot == [32]byte{} || s.headRoot() == newHeadRoot {
+		s.headLock.RUnlock()
 		return
 	}
+	s.headLock.RUnlock()
 
 	if !s.hasBlockInInitSyncOrDB(ctx, newHeadRoot) {
 		log.Debug("New head does not exist in DB. Do nothing")

beacon-chain/blockchain/receive_attestation_test.go

@@ -233,6 +233,8 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	r, err := b.Block.HashTreeRoot()
 	require.NoError(t, err)
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wb))
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertOptimisticBlock(
+		ctx, wb.Block().Slot(), r, bytesutil.ToBytes32(wb.Block().ParentRoot()), [32]byte{}, 0, 0))
 	service.head.root = r // Old head
 	require.Equal(t, 1, len(service.cfg.AttPool.ForkchoiceAttestations()))
 	require.NoError(t, err, service.UpdateHead(ctx))

beacon-chain/blockchain/receive_block.go

@@ -89,8 +89,7 @@ func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []interfaces.Sig
 	defer span.End()
 
 	// Apply state transition on the incoming newly received block batches, one by one.
-	_, _, err := s.onBlockBatch(ctx, blocks, blkRoots)
-	if err != nil {
+	if err := s.onBlockBatch(ctx, blocks, blkRoots); err != nil {
 		err := errors.Wrap(err, "could not process block in batch")
 		tracing.AnnotateError(span, err)
 		return err
@@ -144,7 +143,7 @@ func (s *Service) HasBlock(ctx context.Context, root [32]byte) bool {
 
 // ReceiveAttesterSlashing receives an attester slashing and inserts it to forkchoice
 func (s *Service) ReceiveAttesterSlashing(ctx context.Context, slashing *ethpb.AttesterSlashing) {
-	s.insertSlashingsToForkChoiceStore(ctx, []*ethpb.AttesterSlashing{slashing})
+	s.InsertSlashingsToForkChoiceStore(ctx, []*ethpb.AttesterSlashing{slashing})
 }
 
 func (s *Service) handlePostBlockOperations(b interfaces.BeaconBlock) error {

beacon-chain/blockchain/service.go

@@ -15,6 +15,7 @@ import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/blockchain/store"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache/depositcache"
+	"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"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
@@ -144,13 +145,18 @@ func (s *Service) Start() {
 func (s *Service) Stop() error {
 	defer s.cancel()
 
+	// lock before accessing s.head, s.head.state, s.head.state.FinalizedCheckpoint().Root
+	s.headLock.RLock()
 	if s.cfg.StateGen != nil && s.head != nil && s.head.state != nil {
+		r := s.head.state.FinalizedCheckpoint().Root
+		s.headLock.RUnlock()
 		// Save the last finalized state so that starting up in the following run will be much faster.
-		if err := s.cfg.StateGen.ForceCheckpoint(s.ctx, s.head.state.FinalizedCheckpoint().Root); err != nil {
+		if err := s.cfg.StateGen.ForceCheckpoint(s.ctx, r); err != nil {
 			return err
 		}
+	} else {
+		s.headLock.RUnlock()
 	}
-
 	// Save initial sync cached blocks to the DB before stop.
 	return s.cfg.BeaconDB.SaveBlocks(s.ctx, s.getInitSyncBlocks())
 }
@@ -188,10 +194,16 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 	if err != nil {
 		return errors.Wrap(err, "could not get justified checkpoint")
 	}
+	if justified == nil {
+		return errNilJustifiedCheckpoint
+	}
 	finalized, err := s.cfg.BeaconDB.FinalizedCheckpoint(s.ctx)
 	if err != nil {
 		return errors.Wrap(err, "could not get finalized checkpoint")
 	}
+	if finalized == nil {
+		return errNilFinalizedCheckpoint
+	}
 	s.store = store.New(justified, finalized)
 
 	var forkChoicer f.ForkChoicer
@@ -206,7 +218,7 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 	if err != nil {
 		return errors.Wrap(err, "could not get finalized checkpoint block")
 	}
-	payloadHash, err := getBlockPayloadHash(fb.Block())
+	payloadHash, err := blocks.GetBlockPayloadHash(fb.Block())
 	if err != nil {
 		return errors.Wrap(err, "could not get execution payload hash")
 	}
@@ -225,8 +237,9 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 			return errors.Wrap(err, "could not set finalized block as validated")
 		}
 	}
-
+	s.headLock.RLock()
 	h := s.headBlock().Block()
+	s.headLock.RUnlock()
 	if h.Slot() > fSlot {
 		log.WithFields(logrus.Fields{
 			"startSlot": fSlot,
@@ -439,7 +452,7 @@ func (s *Service) initializeBeaconChain(
 	s.cfg.ChainStartFetcher.ClearPreGenesisData()
 
 	// Update committee shuffled indices for genesis epoch.
-	if err := helpers.UpdateCommitteeCache(genesisState, 0 /* genesis epoch */); err != nil {
+	if err := helpers.UpdateCommitteeCache(ctx, genesisState, 0); err != nil {
 		return nil, err
 	}
 	if err := helpers.UpdateProposerIndicesInCache(ctx, genesisState); err != nil {
@@ -472,7 +485,7 @@ func (s *Service) saveGenesisData(ctx context.Context, genesisState state.Beacon
 	genesisCheckpoint := genesisState.FinalizedCheckpoint()
 	s.store = store.New(genesisCheckpoint, genesisCheckpoint)
 
-	payloadHash, err := getBlockPayloadHash(genesisBlk.Block())
+	payloadHash, err := blocks.GetBlockPayloadHash(genesisBlk.Block())
 	if err != nil {
 		return err
 	}

beacon-chain/builder/BUILD.bazel

@@ -0,0 +1,22 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "option.go",
+        "service.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/builder",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//api/client/builder:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+        "//network:go_default_library",
+        "//network/authorization:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_urfave_cli_v2//:go_default_library",
+    ],
+)

beacon-chain/builder/option.go

@@ -0,0 +1,36 @@
+package builder
+
+import (
+	"github.com/prysmaticlabs/prysm/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/network"
+	"github.com/prysmaticlabs/prysm/network/authorization"
+	"github.com/urfave/cli/v2"
+)
+
+type Option func(s *Service) error
+
+// FlagOptions for builder service flag configurations.
+func FlagOptions(c *cli.Context) ([]Option, error) {
+	endpoint := c.String(flags.MevRelayEndpoint.Name)
+	opts := []Option{
+		WithBuilderEndpoints(endpoint),
+	}
+	return opts, nil
+}
+
+// WithBuilderEndpoints sets the endpoint for the beacon chain builder service.
+func WithBuilderEndpoints(endpoint string) Option {
+	return func(s *Service) error {
+		s.cfg.builderEndpoint = covertEndPoint(endpoint)
+		return nil
+	}
+}
+
+func covertEndPoint(ep string) network.Endpoint {
+	return network.Endpoint{
+		Url: ep,
+		Auth: network.AuthorizationData{ // Auth is not used for builder.
+			Method: authorization.None,
+			Value:  "",
+		}}
+}

beacon-chain/builder/service.go

@@ -0,0 +1,77 @@
+package builder
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/api/client/builder"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/network"
+	v1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+)
+
+// BlockBuilder defines the interface for interacting with the block builder
+type BlockBuilder interface {
+	SubmitBlindedBlock(ctx context.Context, block *ethpb.SignedBlindedBeaconBlockBellatrix) (*v1.ExecutionPayload, error)
+	GetHeader(ctx context.Context, slot types.Slot, parentHash [32]byte, pubKey [48]byte) (*ethpb.SignedBuilderBid, error)
+	Status() error
+	RegisterValidator(ctx context.Context, reg *ethpb.SignedValidatorRegistrationV1) error
+}
+
+// config defines a config struct for dependencies into the service.
+type config struct {
+	builderEndpoint network.Endpoint
+}
+
+// Service defines a service that provides a client for interacting with the beacon chain and MEV relay network.
+type Service struct {
+	cfg *config
+	c   *builder.Client
+}
+
+// NewService instantiates a new service.
+func NewService(ctx context.Context, opts ...Option) (*Service, error) {
+	s := &Service{}
+	for _, opt := range opts {
+		if err := opt(s); err != nil {
+			return nil, err
+		}
+	}
+	if s.cfg.builderEndpoint.Url != "" {
+		c, err := builder.NewClient(s.cfg.builderEndpoint.Url)
+		if err != nil {
+			return nil, err
+		}
+		s.c = c
+	}
+	return s, nil
+}
+
+// Start initializes the service.
+func (*Service) Start() {}
+
+// Stop halts the service.
+func (*Service) Stop() error {
+	return nil
+}
+
+// SubmitBlindedBlock is currently a stub.
+func (*Service) SubmitBlindedBlock(context.Context, *ethpb.SignedBlindedBeaconBlockBellatrix) (*v1.ExecutionPayload, error) {
+	return nil, errors.New("not implemented")
+}
+
+// GetHeader is currently a stub.
+func (*Service) GetHeader(context.Context, types.Slot, [32]byte, [48]byte) (*ethpb.SignedBuilderBid, error) {
+	return nil, errors.New("not implemented")
+}
+
+// Status is currently a stub.
+func (*Service) Status() error {
+	return errors.New("not implemented")
+}
+
+// RegisterValidator is currently a stub.
+func (*Service) RegisterValidator(context.Context, *ethpb.SignedValidatorRegistrationV1) error {
+	return errors.New("not implemented")
+}

beacon-chain/cache/committee.go

@@ -103,9 +103,12 @@ func (c *CommitteeCache) Committee(ctx context.Context, slot types.Slot, seed [3
 
 // AddCommitteeShuffledList adds Committee shuffled list object to the cache. T
 // his method also trims the least recently list if the cache size has ready the max cache size limit.
-func (c *CommitteeCache) AddCommitteeShuffledList(committees *Committees) error {
+func (c *CommitteeCache) AddCommitteeShuffledList(ctx context.Context, committees *Committees) error {
 	c.lock.Lock()
 	defer c.lock.Unlock()
+	if err := ctx.Err(); err != nil {
+		return err
+	}
 	key, err := committeeKeyFn(committees)
 	if err != nil {
 		return err

beacon-chain/cache/committee_disabled.go

@@ -27,7 +27,7 @@ func (c *FakeCommitteeCache) Committee(ctx context.Context, slot types.Slot, see
 
 // AddCommitteeShuffledList adds Committee shuffled list object to the cache. T
 // his method also trims the least recently list if the cache size has ready the max cache size limit.
-func (c *FakeCommitteeCache) AddCommitteeShuffledList(committees *Committees) error {
+func (c *FakeCommitteeCache) AddCommitteeShuffledList(ctx context.Context, committees *Committees) error {
 	return nil
 }
 

beacon-chain/cache/committee_fuzz_test.go

@@ -31,7 +31,7 @@ func TestCommitteeCache_FuzzCommitteesByEpoch(t *testing.T) {
 
 	for i := 0; i < 100000; i++ {
 		fuzzer.Fuzz(c)
-		require.NoError(t, cache.AddCommitteeShuffledList(c))
+		require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), c))
 		_, err := cache.Committee(context.Background(), 0, c.Seed, 0)
 		require.NoError(t, err)
 	}
@@ -46,7 +46,7 @@ func TestCommitteeCache_FuzzActiveIndices(t *testing.T) {
 
 	for i := 0; i < 100000; i++ {
 		fuzzer.Fuzz(c)
-		require.NoError(t, cache.AddCommitteeShuffledList(c))
+		require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), c))
 
 		indices, err := cache.ActiveIndices(context.Background(), c.Seed)
 		require.NoError(t, err)

beacon-chain/cache/committee_test.go

@@ -50,7 +50,7 @@ func TestCommitteeCache_CommitteesByEpoch(t *testing.T) {
 	if indices != nil {
 		t.Error("Expected committee not to exist in empty cache")
 	}
-	require.NoError(t, cache.AddCommitteeShuffledList(item))
+	require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), item))
 
 	wantedIndex := types.CommitteeIndex(0)
 	indices, err = cache.Committee(context.Background(), slot, item.Seed, wantedIndex)
@@ -70,7 +70,7 @@ func TestCommitteeCache_ActiveIndices(t *testing.T) {
 		t.Error("Expected committee not to exist in empty cache")
 	}
 
-	require.NoError(t, cache.AddCommitteeShuffledList(item))
+	require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), item))
 
 	indices, err = cache.ActiveIndices(context.Background(), item.Seed)
 	require.NoError(t, err)
@@ -85,7 +85,7 @@ func TestCommitteeCache_ActiveCount(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, 0, count, "Expected active count not to exist in empty cache")
 
-	require.NoError(t, cache.AddCommitteeShuffledList(item))
+	require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), item))
 
 	count, err = cache.ActiveIndicesCount(context.Background(), item.Seed)
 	require.NoError(t, err)
@@ -101,7 +101,7 @@ func TestCommitteeCache_CanRotate(t *testing.T) {
 	for i := start; i < end; i++ {
 		s := []byte(strconv.Itoa(i))
 		item := &Committees{Seed: bytesutil.ToBytes32(s)}
-		require.NoError(t, cache.AddCommitteeShuffledList(item))
+		require.NoError(t, cache.AddCommitteeShuffledList(context.Background(), item))
 	}
 
 	k := cache.CommitteeCache.Keys()
@@ -134,3 +134,20 @@ func TestCommitteeCacheOutOfRange(t *testing.T) {
 	_, err = cache.Committee(context.Background(), 0, seed, math.MaxUint64) // Overflow!
 	require.NotNil(t, err, "Did not fail as expected")
 }
+
+func TestCommitteeCache_DoesNothingWhenCancelledContext(t *testing.T) {
+	cache := NewCommitteesCache()
+
+	item := &Committees{Seed: [32]byte{'A'}, SortedIndices: []types.ValidatorIndex{1, 2, 3, 4, 5, 6}}
+	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")
+
+	cancelled, cancel := context.WithCancel(context.Background())
+	cancel()
+	require.ErrorIs(t, cache.AddCommitteeShuffledList(cancelled, item), context.Canceled)
+
+	count, err = cache.ActiveIndicesCount(context.Background(), item.Seed)
+	require.NoError(t, err)
+	assert.Equal(t, 0, count)
+}

beacon-chain/core/altair/epoch_precompute.go

@@ -47,7 +47,7 @@ func InitializePrecomputeValidators(ctx context.Context, beaconState state.Beaco
 				return err
 			}
 		}
-		// Set validator's active status for preivous epoch.
+		// Set validator's active status for previous epoch.
 		if helpers.IsActiveValidatorUsingTrie(val, prevEpoch) {
 			v.IsActivePrevEpoch = true
 			bal.ActivePrevEpoch, err = math.Add64(bal.ActivePrevEpoch, val.EffectiveBalance())

beacon-chain/core/blocks/BUILD.bazel

@@ -31,6 +31,7 @@ go_library(
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/forks/bellatrix:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
@@ -40,7 +41,6 @@ go_library(
         "//crypto/bls:go_default_library",
         "//crypto/hash:go_default_library",
         "//encoding/bytesutil:go_default_library",
-        "//encoding/ssz:go_default_library",
         "//math:go_default_library",
         "//network/forks:go_default_library",
         "//proto/engine/v1:go_default_library",
@@ -89,6 +89,7 @@ go_test(
         "//beacon-chain/state/v1:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/forks/bellatrix:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
         "//container/trie:go_default_library",

beacon-chain/core/blocks/payload.go

@@ -7,11 +7,10 @@ import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
-	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/consensus-types/forks/bellatrix"
 	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/encoding/ssz"
 	enginev1 "github.com/prysmaticlabs/prysm/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/runtime/version"
@@ -41,7 +40,7 @@ func IsMergeTransitionComplete(st state.BeaconState) (bool, error) {
 	if err != nil {
 		return false, err
 	}
-	return !isEmptyHeader(h), nil
+	return !bellatrix.IsEmptyHeader(h), nil
 }
 
 // IsMergeTransitionBlockUsingPreStatePayloadHeader returns true if the input block is the terminal merge block.
@@ -51,7 +50,7 @@ func IsMergeTransitionBlockUsingPreStatePayloadHeader(h *ethpb.ExecutionPayloadH
 	if h == nil || body == nil {
 		return false, errors.New("nil header or block body")
 	}
-	if !isEmptyHeader(h) {
+	if !bellatrix.IsEmptyHeader(h) {
 		return false, nil
 	}
 	return IsExecutionBlock(body)
@@ -74,7 +73,7 @@ func IsExecutionBlock(body interfaces.BeaconBlockBody) (bool, error) {
 		return false, err
 	default:
 	}
-	return !IsEmptyPayload(payload), nil
+	return !bellatrix.IsEmptyPayload(payload), nil
 }
 
 // IsExecutionEnabled returns true if the beacon chain can begin executing.
@@ -100,7 +99,7 @@ func IsExecutionEnabled(st state.BeaconState, body interfaces.BeaconBlockBody) (
 // IsExecutionEnabledUsingHeader returns true if the execution is enabled using post processed payload header and block body.
 // This is an optimized version of IsExecutionEnabled where beacon state is not required as an argument.
 func IsExecutionEnabledUsingHeader(header *ethpb.ExecutionPayloadHeader, body interfaces.BeaconBlockBody) (bool, error) {
-	if !isEmptyHeader(header) {
+	if !bellatrix.IsEmptyHeader(header) {
 		return true, nil
 	}
 	return IsExecutionBlock(body)
@@ -205,7 +204,7 @@ func ProcessPayload(st state.BeaconState, payload *enginev1.ExecutionPayload) (s
 		return nil, err
 	}
 
-	header, err := PayloadToHeader(payload)
+	header, err := bellatrix.PayloadToHeader(payload)
 	if err != nil {
 		return nil, err
 	}
@@ -215,126 +214,6 @@ func ProcessPayload(st state.BeaconState, payload *enginev1.ExecutionPayload) (s
 	return st, nil
 }
 
-// PayloadToHeader converts `payload` into execution payload header format.
-func PayloadToHeader(payload *enginev1.ExecutionPayload) (*ethpb.ExecutionPayloadHeader, error) {
-	txRoot, err := ssz.TransactionsRoot(payload.Transactions)
-	if err != nil {
-		return nil, err
-	}
-
-	return &ethpb.ExecutionPayloadHeader{
-		ParentHash:       bytesutil.SafeCopyBytes(payload.ParentHash),
-		FeeRecipient:     bytesutil.SafeCopyBytes(payload.FeeRecipient),
-		StateRoot:        bytesutil.SafeCopyBytes(payload.StateRoot),
-		ReceiptsRoot:     bytesutil.SafeCopyBytes(payload.ReceiptsRoot),
-		LogsBloom:        bytesutil.SafeCopyBytes(payload.LogsBloom),
-		PrevRandao:       bytesutil.SafeCopyBytes(payload.PrevRandao),
-		BlockNumber:      payload.BlockNumber,
-		GasLimit:         payload.GasLimit,
-		GasUsed:          payload.GasUsed,
-		Timestamp:        payload.Timestamp,
-		ExtraData:        bytesutil.SafeCopyBytes(payload.ExtraData),
-		BaseFeePerGas:    bytesutil.SafeCopyBytes(payload.BaseFeePerGas),
-		BlockHash:        bytesutil.SafeCopyBytes(payload.BlockHash),
-		TransactionsRoot: txRoot[:],
-	}, nil
-}
-
-func IsEmptyPayload(p *enginev1.ExecutionPayload) bool {
-	if p == nil {
-		return true
-	}
-	if !bytes.Equal(p.ParentHash, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(p.FeeRecipient, make([]byte, fieldparams.FeeRecipientLength)) {
-		return false
-	}
-	if !bytes.Equal(p.StateRoot, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(p.ReceiptsRoot, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(p.LogsBloom, make([]byte, fieldparams.LogsBloomLength)) {
-		return false
-	}
-	if !bytes.Equal(p.PrevRandao, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(p.BaseFeePerGas, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(p.BlockHash, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if len(p.Transactions) != 0 {
-		return false
-	}
-	if len(p.ExtraData) != 0 {
-		return false
-	}
-	if p.BlockNumber != 0 {
-		return false
-	}
-	if p.GasLimit != 0 {
-		return false
-	}
-	if p.GasUsed != 0 {
-		return false
-	}
-	if p.Timestamp != 0 {
-		return false
-	}
-	return true
-}
-
-func isEmptyHeader(h *ethpb.ExecutionPayloadHeader) bool {
-	if !bytes.Equal(h.ParentHash, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(h.FeeRecipient, make([]byte, fieldparams.FeeRecipientLength)) {
-		return false
-	}
-	if !bytes.Equal(h.StateRoot, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(h.ReceiptsRoot, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(h.LogsBloom, make([]byte, fieldparams.LogsBloomLength)) {
-		return false
-	}
-	if !bytes.Equal(h.PrevRandao, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(h.BaseFeePerGas, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(h.BlockHash, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if !bytes.Equal(h.TransactionsRoot, make([]byte, fieldparams.RootLength)) {
-		return false
-	}
-	if len(h.ExtraData) != 0 {
-		return false
-	}
-	if h.BlockNumber != 0 {
-		return false
-	}
-	if h.GasLimit != 0 {
-		return false
-	}
-	if h.GasUsed != 0 {
-		return false
-	}
-	if h.Timestamp != 0 {
-		return false
-	}
-	return true
-}
-
 // ValidatePayloadHeaderWhenMergeCompletes validates the payload header when the merge completes.
 func ValidatePayloadHeaderWhenMergeCompletes(st state.BeaconState, header *ethpb.ExecutionPayloadHeader) error {
 	// Skip validation if the state is not merge compatible.
@@ -393,3 +272,16 @@ func ProcessPayloadHeader(st state.BeaconState, header *ethpb.ExecutionPayloadHe
 	}
 	return st, nil
 }
+
+// GetBlockPayloadHash returns the hash of the execution payload of the block
+func GetBlockPayloadHash(blk interfaces.BeaconBlock) ([32]byte, error) {
+	payloadHash := [32]byte{}
+	if IsPreBellatrixVersion(blk.Version()) {
+		return payloadHash, nil
+	}
+	payload, err := blk.Body().ExecutionPayload()
+	if err != nil {
+		return payloadHash, err
+	}
+	return bytesutil.ToBytes32(payload.BlockHash), nil
+}

beacon-chain/core/blocks/payload_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/consensus-types/forks/bellatrix"
 	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/encoding/ssz"
@@ -669,7 +670,7 @@ func Test_ProcessPayload(t *testing.T) {
 				require.Equal(t, tt.err.Error(), err.Error())
 			} else {
 				require.Equal(t, tt.err, err)
-				want, err := blocks.PayloadToHeader(tt.payload)
+				want, err := bellatrix.PayloadToHeader(tt.payload)
 				require.Equal(t, tt.err, err)
 				got, err := st.LatestExecutionPayloadHeader()
 				require.NoError(t, err)
@@ -824,7 +825,7 @@ func Test_ValidatePayloadHeaderWhenMergeCompletes(t *testing.T) {
 
 func Test_PayloadToHeader(t *testing.T) {
 	p := emptyPayload()
-	h, err := blocks.PayloadToHeader(p)
+	h, err := bellatrix.PayloadToHeader(p)
 	require.NoError(t, err)
 	txRoot, err := ssz.TransactionsRoot(p.Transactions)
 	require.NoError(t, err)

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

@@ -28,6 +28,7 @@ go_library(
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@io_opencensus_go//trace:go_default_library",
     ],
 )
@@ -43,11 +44,13 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/core/altair: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",
+        "//beacon-chain/state/v2:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",

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

@@ -2,6 +2,7 @@ package precompute
 
 import (
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
@@ -9,6 +10,24 @@ import (
 	"github.com/prysmaticlabs/prysm/time/slots"
 )
 
+var errNilState = errors.New("nil state")
+
+// UnrealizedCheckpoints returns the justification and finalization checkpoints of the
+// given state as if it was progressed with empty slots until the next epoch.
+func UnrealizedCheckpoints(st state.BeaconState) (*ethpb.Checkpoint, *ethpb.Checkpoint, error) {
+	if st == nil || st.IsNil() {
+		return nil, nil, errNilState
+	}
+
+	activeBalance, prevTarget, currentTarget, err := st.UnrealizedCheckpointBalances()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	justification := processJustificationBits(st, activeBalance, prevTarget, currentTarget)
+	return computeCheckpoints(st, justification)
+}
+
 // ProcessJustificationAndFinalizationPreCompute processes justification and finalization during
 // epoch processing. This is where a beacon node can justify and finalize a new epoch.
 // Note: this is an optimized version by passing in precomputed total and attesting balances.
@@ -34,12 +53,55 @@ func ProcessJustificationAndFinalizationPreCompute(state state.BeaconState, pBal
 		return state, nil
 	}
 
-	return weighJustificationAndFinalization(state, pBal.ActiveCurrentEpoch, pBal.PrevEpochTargetAttested, pBal.CurrentEpochTargetAttested)
+	newBits := processJustificationBits(state, pBal.ActiveCurrentEpoch, pBal.PrevEpochTargetAttested, pBal.CurrentEpochTargetAttested)
+
+	return weighJustificationAndFinalization(state, newBits)
 }
 
-// weighJustificationAndFinalization processes justification and finalization during
+// processJustificationBits processes the justification bits during epoch processing.
+func processJustificationBits(state state.BeaconState, totalActiveBalance, prevEpochTargetBalance, currEpochTargetBalance uint64) bitfield.Bitvector4 {
+	newBits := state.JustificationBits()
+	newBits.Shift(1)
+	// If 2/3 or more of total balance attested in the previous epoch.
+	if 3*prevEpochTargetBalance >= 2*totalActiveBalance {
+		newBits.SetBitAt(1, true)
+	}
+
+	if 3*currEpochTargetBalance >= 2*totalActiveBalance {
+		newBits.SetBitAt(0, true)
+	}
+
+	return newBits
+}
+
+// updateJustificationAndFinalization processes justification and finalization during
 // epoch processing. This is where a beacon node can justify and finalize a new epoch.
-//
+func weighJustificationAndFinalization(state state.BeaconState, newBits bitfield.Bitvector4) (state.BeaconState, error) {
+	jc, fc, err := computeCheckpoints(state, newBits)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := state.SetPreviousJustifiedCheckpoint(state.CurrentJustifiedCheckpoint()); err != nil {
+		return nil, err
+	}
+
+	if err := state.SetCurrentJustifiedCheckpoint(jc); err != nil {
+		return nil, err
+	}
+
+	if err := state.SetJustificationBits(newBits); err != nil {
+		return nil, err
+	}
+
+	if err := state.SetFinalizedCheckpoint(fc); err != nil {
+		return nil, err
+	}
+	return state, nil
+}
+
+// computeCheckpoints computes the new Justification and Finalization
+// checkpoints at epoch transition
 // Spec pseudocode definition:
 // def weigh_justification_and_finalization(state: BeaconState,
 //                                         total_active_balance: Gwei,
@@ -77,88 +139,57 @@ func ProcessJustificationAndFinalizationPreCompute(state state.BeaconState, pBal
 //    # The 1st/2nd most recent epochs are justified, the 1st using the 2nd as source
 //    if all(bits[0:2]) and old_current_justified_checkpoint.epoch + 1 == current_epoch:
 //        state.finalized_checkpoint = old_current_justified_checkpoint
-func weighJustificationAndFinalization(state state.BeaconState,
-	totalActiveBalance, prevEpochTargetBalance, currEpochTargetBalance uint64) (state.BeaconState, error) {
+func computeCheckpoints(state state.BeaconState, newBits bitfield.Bitvector4) (*ethpb.Checkpoint, *ethpb.Checkpoint, error) {
 	prevEpoch := time.PrevEpoch(state)
 	currentEpoch := time.CurrentEpoch(state)
 	oldPrevJustifiedCheckpoint := state.PreviousJustifiedCheckpoint()
 	oldCurrJustifiedCheckpoint := state.CurrentJustifiedCheckpoint()
 
-	// Process justifications
-	if err := state.SetPreviousJustifiedCheckpoint(state.CurrentJustifiedCheckpoint()); err != nil {
-		return nil, err
-	}
-	newBits := state.JustificationBits()
-	newBits.Shift(1)
-	if err := state.SetJustificationBits(newBits); err != nil {
-		return nil, err
-	}
-
-	// Note: the spec refers to the bit index position starting at 1 instead of starting at zero.
-	// We will use that paradigm here for consistency with the godoc spec definition.
-
-	// If 2/3 or more of total balance attested in the previous epoch.
-	if 3*prevEpochTargetBalance >= 2*totalActiveBalance {
-		blockRoot, err := helpers.BlockRoot(state, prevEpoch)
-		if err != nil {
-			return nil, errors.Wrapf(err, "could not get block root for previous epoch %d", prevEpoch)
-		}
-		if err := state.SetCurrentJustifiedCheckpoint(&ethpb.Checkpoint{Epoch: prevEpoch, Root: blockRoot}); err != nil {
-			return nil, err
-		}
-		newBits = state.JustificationBits()
-		newBits.SetBitAt(1, true)
-		if err := state.SetJustificationBits(newBits); err != nil {
-			return nil, err
-		}
-	}
+	justifiedCheckpoint := state.CurrentJustifiedCheckpoint()
+	finalizedCheckpoint := state.FinalizedCheckpoint()
 
 	// If 2/3 or more of the total balance attested in the current epoch.
-	if 3*currEpochTargetBalance >= 2*totalActiveBalance {
+	if newBits.BitAt(0) {
 		blockRoot, err := helpers.BlockRoot(state, currentEpoch)
 		if err != nil {
-			return nil, errors.Wrapf(err, "could not get block root for current epoch %d", prevEpoch)
+			return nil, nil, errors.Wrapf(err, "could not get block root for current epoch %d", currentEpoch)
 		}
-		if err := state.SetCurrentJustifiedCheckpoint(&ethpb.Checkpoint{Epoch: currentEpoch, Root: blockRoot}); err != nil {
-			return nil, err
-		}
-		newBits = state.JustificationBits()
-		newBits.SetBitAt(0, true)
-		if err := state.SetJustificationBits(newBits); err != nil {
-			return nil, err
+		justifiedCheckpoint.Epoch = currentEpoch
+		justifiedCheckpoint.Root = blockRoot
+	} else if newBits.BitAt(1) {
+		// If 2/3 or more of total balance attested in the previous epoch.
+		blockRoot, err := helpers.BlockRoot(state, prevEpoch)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "could not get block root for previous epoch %d", prevEpoch)
 		}
+		justifiedCheckpoint.Epoch = prevEpoch
+		justifiedCheckpoint.Root = blockRoot
 	}
 
 	// Process finalization according to Ethereum Beacon Chain specification.
-	justification := state.JustificationBits().Bytes()[0]
+	if len(newBits) == 0 {
+		return nil, nil, errors.New("empty justification bits")
+	}
+	justification := newBits.Bytes()[0]
 
 	// 2nd/3rd/4th (0b1110) most recent epochs are justified, the 2nd using the 4th as source.
 	if justification&0x0E == 0x0E && (oldPrevJustifiedCheckpoint.Epoch+3) == currentEpoch {
-		if err := state.SetFinalizedCheckpoint(oldPrevJustifiedCheckpoint); err != nil {
-			return nil, err
-		}
+		finalizedCheckpoint = oldPrevJustifiedCheckpoint
 	}
 
 	// 2nd/3rd (0b0110) most recent epochs are justified, the 2nd using the 3rd as source.
 	if justification&0x06 == 0x06 && (oldPrevJustifiedCheckpoint.Epoch+2) == currentEpoch {
-		if err := state.SetFinalizedCheckpoint(oldPrevJustifiedCheckpoint); err != nil {
-			return nil, err
-		}
+		finalizedCheckpoint = oldPrevJustifiedCheckpoint
 	}
 
 	// 1st/2nd/3rd (0b0111) most recent epochs are justified, the 1st using the 3rd as source.
 	if justification&0x07 == 0x07 && (oldCurrJustifiedCheckpoint.Epoch+2) == currentEpoch {
-		if err := state.SetFinalizedCheckpoint(oldCurrJustifiedCheckpoint); err != nil {
-			return nil, err
-		}
+		finalizedCheckpoint = oldCurrJustifiedCheckpoint
 	}
 
 	// The 1st/2nd (0b0011) most recent epochs are justified, the 1st using the 2nd as source
 	if justification&0x03 == 0x03 && (oldCurrJustifiedCheckpoint.Epoch+1) == currentEpoch {
-		if err := state.SetFinalizedCheckpoint(oldCurrJustifiedCheckpoint); err != nil {
-			return nil, err
-		}
+		finalizedCheckpoint = oldCurrJustifiedCheckpoint
 	}
-
-	return state, nil
+	return justifiedCheckpoint, finalizedCheckpoint, nil
 }

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

@@ -1,11 +1,14 @@
 package precompute_test
 
 import (
+	"context"
 	"testing"
 
 	"github.com/prysmaticlabs/go-bitfield"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/altair"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/epoch/precompute"
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
+	v2 "github.com/prysmaticlabs/prysm/beacon-chain/state/v2"
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
@@ -123,3 +126,127 @@ func TestProcessJustificationAndFinalizationPreCompute_JustifyPrevEpoch(t *testi
 	assert.DeepEqual(t, params.BeaconConfig().ZeroHash[:], newState.FinalizedCheckpoint().Root)
 	assert.Equal(t, types.Epoch(0), newState.FinalizedCheckpointEpoch(), "Unexpected finalized epoch")
 }
+
+func TestUnrealizedCheckpoints(t *testing.T) {
+	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
+	balances := make([]uint64, len(validators))
+	for i := 0; i < len(validators); i++ {
+		validators[i] = &ethpb.Validator{
+			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
+			EffectiveBalance: params.BeaconConfig().MaxEffectiveBalance,
+		}
+		balances[i] = params.BeaconConfig().MaxEffectiveBalance
+	}
+	pjr := [32]byte{'p'}
+	cjr := [32]byte{'c'}
+	je := types.Epoch(3)
+	fe := types.Epoch(2)
+	pjcp := &ethpb.Checkpoint{Root: pjr[:], Epoch: fe}
+	cjcp := &ethpb.Checkpoint{Root: cjr[:], Epoch: je}
+	fcp := &ethpb.Checkpoint{Root: pjr[:], Epoch: fe}
+	tests := []struct {
+		name                                 string
+		slot                                 types.Slot
+		prevVals, currVals                   int
+		expectedJustified, expectedFinalized types.Epoch // The expected unrealized checkpoint epochs
+	}{
+		{
+			"Not enough votes, keep previous justification",
+			129,
+			len(validators) / 3,
+			len(validators) / 3,
+			je,
+			fe,
+		},
+		{
+			"Not enough votes, keep previous justification, N+2",
+			161,
+			len(validators) / 3,
+			len(validators) / 3,
+			je,
+			fe,
+		},
+		{
+			"Enough to justify previous epoch but not current",
+			129,
+			2*len(validators)/3 + 3,
+			len(validators) / 3,
+			je,
+			fe,
+		},
+		{
+			"Enough to justify previous epoch but not current, N+2",
+			161,
+			2*len(validators)/3 + 3,
+			len(validators) / 3,
+			je + 1,
+			fe,
+		},
+		{
+			"Enough to justify current epoch",
+			129,
+			len(validators) / 3,
+			2*len(validators)/3 + 3,
+			je + 1,
+			fe,
+		},
+		{
+			"Enough to justify current epoch, but not previous",
+			161,
+			len(validators) / 3,
+			2*len(validators)/3 + 3,
+			je + 2,
+			fe,
+		},
+		{
+			"Enough to justify current and previous",
+			161,
+			2*len(validators)/3 + 3,
+			2*len(validators)/3 + 3,
+			je + 2,
+			fe,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			base := &ethpb.BeaconStateAltair{
+				RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
+
+				Validators:                  validators,
+				Slot:                        test.slot,
+				CurrentEpochParticipation:   make([]byte, params.BeaconConfig().MinGenesisActiveValidatorCount),
+				PreviousEpochParticipation:  make([]byte, params.BeaconConfig().MinGenesisActiveValidatorCount),
+				Balances:                    balances,
+				PreviousJustifiedCheckpoint: pjcp,
+				CurrentJustifiedCheckpoint:  cjcp,
+				FinalizedCheckpoint:         fcp,
+				InactivityScores:            make([]uint64, len(validators)),
+				JustificationBits:           make(bitfield.Bitvector4, 1),
+			}
+			for i := 0; i < test.prevVals; i++ {
+				base.PreviousEpochParticipation[i] = 0xFF
+			}
+			for i := 0; i < test.currVals; i++ {
+				base.CurrentEpochParticipation[i] = 0xFF
+			}
+			if test.slot > 130 {
+				base.JustificationBits.SetBitAt(2, true)
+				base.JustificationBits.SetBitAt(3, true)
+			} else {
+				base.JustificationBits.SetBitAt(1, true)
+				base.JustificationBits.SetBitAt(2, true)
+			}
+
+			state, err := v2.InitializeFromProto(base)
+			require.NoError(t, err)
+
+			_, _, err = altair.InitializePrecomputeValidators(context.Background(), state)
+			require.NoError(t, err)
+
+			jc, fc, err := precompute.UnrealizedCheckpoints(state)
+			require.NoError(t, err)
+			require.DeepEqual(t, test.expectedJustified, jc.Epoch)
+			require.DeepEqual(t, test.expectedFinalized, fc.Epoch)
+		})
+	}
+}

beacon-chain/core/helpers/beacon_committee.go

@@ -285,7 +285,7 @@ func ShuffledIndices(s state.ReadOnlyBeaconState, epoch types.Epoch) ([]types.Va
 
 // UpdateCommitteeCache gets called at the beginning of every epoch to cache the committee shuffled indices
 // list with committee index and epoch number. It caches the shuffled indices for current epoch and next epoch.
-func UpdateCommitteeCache(state state.ReadOnlyBeaconState, epoch types.Epoch) error {
+func UpdateCommitteeCache(ctx context.Context, state state.ReadOnlyBeaconState, epoch types.Epoch) error {
 	for _, e := range []types.Epoch{epoch, epoch + 1} {
 		seed, err := Seed(state, e, params.BeaconConfig().DomainBeaconAttester)
 		if err != nil {
@@ -311,7 +311,7 @@ func UpdateCommitteeCache(state state.ReadOnlyBeaconState, epoch types.Epoch) er
 			return sortedIndices[i] < sortedIndices[j]
 		})
 
-		if err := committeeCache.AddCommitteeShuffledList(&cache.Committees{
+		if err := committeeCache.AddCommitteeShuffledList(ctx, &cache.Committees{
 			ShuffledIndices: shuffledIndices,
 			CommitteeCount:  uint64(params.BeaconConfig().SlotsPerEpoch.Mul(count)),
 			Seed:            seed,

beacon-chain/core/helpers/beacon_committee_test.go

@@ -386,7 +386,7 @@ func TestUpdateCommitteeCache_CanUpdate(t *testing.T) {
 		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
 	})
 	require.NoError(t, err)
-	require.NoError(t, UpdateCommitteeCache(state, time.CurrentEpoch(state)))
+	require.NoError(t, UpdateCommitteeCache(context.Background(), state, time.CurrentEpoch(state)))
 
 	epoch := types.Epoch(1)
 	idx := types.CommitteeIndex(1)

beacon-chain/core/helpers/validators.go

@@ -126,7 +126,7 @@ func ActiveValidatorIndices(ctx context.Context, s state.ReadOnlyBeaconState, ep
 		return nil, err
 	}
 
-	if err := UpdateCommitteeCache(s, epoch); err != nil {
+	if err := UpdateCommitteeCache(ctx, s, epoch); err != nil {
 		return nil, errors.Wrap(err, "could not update committee cache")
 	}
 
@@ -175,7 +175,7 @@ func ActiveValidatorCount(ctx context.Context, s state.ReadOnlyBeaconState, epoc
 		return 0, err
 	}
 
-	if err := UpdateCommitteeCache(s, epoch); err != nil {
+	if err := UpdateCommitteeCache(ctx, s, epoch); err != nil {
 		return 0, errors.Wrap(err, "could not update committee cache")
 	}
 

beacon-chain/core/helpers/validators_test.go

@@ -301,7 +301,7 @@ func TestActiveValidatorCount_Genesis(t *testing.T) {
 	// Preset cache to a bad count.
 	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}}))
+	require.NoError(t, committeeCache.AddCommitteeShuffledList(context.Background(), &cache.Committees{Seed: seed, ShuffledIndices: []types.ValidatorIndex{1, 2, 3}}))
 	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")

beacon-chain/core/signing/BUILD.bazel

@@ -4,6 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "domain.go",
+        "signature.go",
         "signing_root.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/core/signing",
@@ -24,6 +25,7 @@ go_test(
     name = "go_default_test",
     srcs = [
         "domain_test.go",
+        "signature_test.go",
         "signing_root_test.go",
     ],
     embed = [":go_default_library"],
@@ -40,6 +42,7 @@ 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",
     ],
 )

beacon-chain/core/signing/signature.go

@@ -0,0 +1,33 @@
+package signing
+
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+)
+
+var ErrNilRegistration = errors.New("nil signed registration")
+
+// VerifyRegistrationSignature verifies the signature of a validator's registration.
+func VerifyRegistrationSignature(
+	e types.Epoch,
+	f *ethpb.Fork,
+	sr *ethpb.SignedValidatorRegistrationV1,
+	genesisRoot []byte,
+) error {
+	if sr == nil || sr.Message == nil {
+		return ErrNilRegistration
+	}
+
+	d := params.BeaconConfig().DomainApplicationBuilder
+	sd, err := Domain(f, e, d, genesisRoot)
+	if err != nil {
+		return err
+	}
+
+	if err := VerifySigningRoot(sr.Message, sr.Message.Pubkey, sr.Signature, sd); err != nil {
+		return ErrSigFailedToVerify
+	}
+	return nil
+}

beacon-chain/core/signing/signature_test.go

@@ -0,0 +1,44 @@
+package signing_test
+
+import (
+	"testing"
+	"time"
+
+	"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/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
+	"github.com/prysmaticlabs/prysm/time/slots"
+)
+
+func TestVerifyRegistrationSignature(t *testing.T) {
+	sk, err := bls.RandKey()
+	require.NoError(t, err)
+	reg := &ethpb.ValidatorRegistrationV1{
+		FeeRecipient: bytesutil.PadTo([]byte("fee"), 20),
+		GasLimit:     123456,
+		Timestamp:    uint64(time.Now().Unix()),
+		Pubkey:       sk.PublicKey().Marshal(),
+	}
+	st, _ := util.DeterministicGenesisState(t, 1)
+	d := params.BeaconConfig().DomainApplicationBuilder
+	e := slots.ToEpoch(st.Slot())
+	sig, err := signing.ComputeDomainAndSign(st, e, reg, d, sk)
+	require.NoError(t, err)
+	sReg := &ethpb.SignedValidatorRegistrationV1{
+		Message:   reg,
+		Signature: sig,
+	}
+	f := st.Fork()
+	g := st.GenesisValidatorsRoot()
+	require.NoError(t, signing.VerifyRegistrationSignature(e, f, sReg, g))
+
+	sReg.Signature = []byte("bad")
+	require.ErrorIs(t, signing.VerifyRegistrationSignature(e, f, sReg, g), signing.ErrSigFailedToVerify)
+
+	sReg.Message = nil
+	require.ErrorIs(t, signing.VerifyRegistrationSignature(e, f, sReg, g), signing.ErrNilRegistration)
+}

beacon-chain/core/transition/benchmarks_test.go

@@ -53,7 +53,7 @@ func BenchmarkExecuteStateTransition_WithCache(b *testing.B) {
 	// some attestations in block are from previous epoch
 	currentSlot := beaconState.Slot()
 	require.NoError(b, beaconState.SetSlot(beaconState.Slot()-params.BeaconConfig().SlotsPerEpoch))
-	require.NoError(b, helpers.UpdateCommitteeCache(beaconState, time.CurrentEpoch(beaconState)))
+	require.NoError(b, helpers.UpdateCommitteeCache(context.Background(), beaconState, time.CurrentEpoch(beaconState)))
 	require.NoError(b, beaconState.SetSlot(currentSlot))
 	// Run the state transition once to populate the cache.
 	wsb, err := wrapper.WrappedSignedBeaconBlock(block)
@@ -81,7 +81,7 @@ func BenchmarkProcessEpoch_2FullEpochs(b *testing.B) {
 	// some attestations in block are from previous epoch
 	currentSlot := beaconState.Slot()
 	require.NoError(b, beaconState.SetSlot(beaconState.Slot()-params.BeaconConfig().SlotsPerEpoch))
-	require.NoError(b, helpers.UpdateCommitteeCache(beaconState, time.CurrentEpoch(beaconState)))
+	require.NoError(b, helpers.UpdateCommitteeCache(context.Background(), beaconState, time.CurrentEpoch(beaconState)))
 	require.NoError(b, beaconState.SetSlot(currentSlot))
 
 	b.ResetTimer()

beacon-chain/core/validators/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "//beacon-chain/state:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//math:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",

beacon-chain/core/validators/validator.go

@@ -13,6 +13,7 @@ import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	mathutil "github.com/prysmaticlabs/prysm/math"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/time/slots"
 )
@@ -72,7 +73,11 @@ func InitiateValidatorExit(ctx context.Context, s state.BeaconState, idx types.V
 	exitQueueChurn := uint64(0)
 	err = s.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
 		if val.ExitEpoch() == exitQueueEpoch {
-			exitQueueChurn++
+			var mErr error
+			exitQueueChurn, mErr = mathutil.Add64(exitQueueChurn, 1)
+			if mErr != nil {
+				return mErr
+			}
 		}
 		return nil
 	})
@@ -89,10 +94,16 @@ func InitiateValidatorExit(ctx context.Context, s state.BeaconState, idx types.V
 	}
 
 	if exitQueueChurn >= churn {
-		exitQueueEpoch++
+		exitQueueEpoch, err = exitQueueEpoch.SafeAdd(1)
+		if err != nil {
+			return nil, err
+		}
 	}
 	validator.ExitEpoch = exitQueueEpoch
-	validator.WithdrawableEpoch = exitQueueEpoch + params.BeaconConfig().MinValidatorWithdrawabilityDelay
+	validator.WithdrawableEpoch, err = exitQueueEpoch.SafeAddEpoch(params.BeaconConfig().MinValidatorWithdrawabilityDelay)
+	if err != nil {
+		return nil, err
+	}
 	if err := s.UpdateValidatorAtIndex(idx, validator); err != nil {
 		return nil, err
 	}

beacon-chain/core/validators/validator_test.go

@@ -99,6 +99,17 @@ func TestInitiateValidatorExit_ChurnOverflow(t *testing.T) {
 	assert.Equal(t, wantedEpoch, v.ExitEpoch, "Exit epoch did not cover overflow case")
 }
 
+func TestInitiateValidatorExit_WithdrawalOverflows(t *testing.T) {
+	base := &ethpb.BeaconState{Validators: []*ethpb.Validator{
+		{ExitEpoch: params.BeaconConfig().FarFutureEpoch - 1},
+		{EffectiveBalance: params.BeaconConfig().EjectionBalance, ExitEpoch: params.BeaconConfig().FarFutureEpoch},
+	}}
+	state, err := v1.InitializeFromProto(base)
+	require.NoError(t, err)
+	_, err = InitiateValidatorExit(context.Background(), state, 1)
+	require.ErrorContains(t, "addition overflows", err)
+}
+
 func TestSlashValidator_OK(t *testing.T) {
 	validatorCount := 100
 	registry := make([]*ethpb.Validator, 0, validatorCount)

beacon-chain/db/kv/BUILD.bazel

@@ -66,6 +66,7 @@ go_library(
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
         "@com_github_prysmaticlabs_prombbolt//:go_default_library",
+        "@com_github_schollz_progressbar_v3//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@io_etcd_go_bbolt//:go_default_library",
         "@io_opencensus_go//trace:go_default_library",

beacon-chain/db/kv/blocks.go

@@ -403,33 +403,50 @@ func (s *Store) HighestSlotBlocksBelow(ctx context.Context, slot types.Slot) ([]
 	ctx, span := trace.StartSpan(ctx, "BeaconDB.HighestSlotBlocksBelow")
 	defer span.End()
 
-	var best []byte
-	if err := s.db.View(func(tx *bolt.Tx) error {
+	var root [32]byte
+	sk := bytesutil.Uint64ToBytesBigEndian(uint64(slot))
+	err := s.db.View(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(blockSlotIndicesBucket)
-		// Iterate through the index, which is in byte sorted order.
 		c := bkt.Cursor()
-		for s, root := c.First(); s != nil; s, root = c.Next() {
+		// The documentation for Seek says:
+		// "If the key does not exist then the next key is used. If no keys follow, a nil key is returned."
+		seekPast := func(ic *bolt.Cursor, k []byte) ([]byte, []byte) {
+			ik, iv := ic.Seek(k)
+			// So if there are slots in the index higher than the requested slot, sl will be equal to the key that is
+			// one higher than the value we want. If the slot argument is higher than the highest value in the index,
+			// we'll get a nil value for `sl`. In that case we'll go backwards from Cursor.Last().
+			if ik == nil {
+				return ic.Last()
+			}
+			return ik, iv
+		}
+		// re loop condition: when .Prev() rewinds past the beginning off the collection, the loop will terminate,
+		// because `sl` will be nil. If we don't find a value for `root` before iteration ends,
+		// `root` will be the zero value, in which case this function will return the genesis block.
+		for sl, r := seekPast(c, sk); sl != nil; sl, r = c.Prev() {
 			if ctx.Err() != nil {
 				return ctx.Err()
 			}
-			key := bytesutil.BytesToSlotBigEndian(s)
-			if root == nil {
+			if r == nil {
 				continue
 			}
-			if key >= slot {
+			bs := bytesutil.BytesToSlotBigEndian(sl)
+			// Iterating through the index using .Prev will move from higher to lower, so the first key we find behind
+			// the requested slot must be the highest block below that slot.
+			if slot > bs {
+				root = bytesutil.ToBytes32(r)
 				break
 			}
-			best = root
 		}
 		return nil
-	}); err != nil {
+	})
+	if err != nil {
 		return nil, err
 	}
 
 	var blk interfaces.SignedBeaconBlock
-	var err error
-	if best != nil {
-		blk, err = s.Block(ctx, bytesutil.ToBytes32(best))
+	if root != params.BeaconConfig().ZeroHash {
+		blk, err = s.Block(ctx, root)
 		if err != nil {
 			return nil, err
 		}
@@ -440,7 +457,6 @@ func (s *Store) HighestSlotBlocksBelow(ctx context.Context, slot types.Slot) ([]
 			return nil, err
 		}
 	}
-
 	return []interfaces.SignedBeaconBlock{blk}, nil
 }
 
@@ -453,8 +469,20 @@ func (s *Store) FeeRecipientByValidatorID(ctx context.Context, id types.Validato
 	err := s.db.View(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(feeRecipientBucket)
 		addr = bkt.Get(bytesutil.Uint64ToBytesBigEndian(uint64(id)))
+		// IF the fee recipient is not found in the standard fee recipient bucket, then
+		// check the registration bucket. The fee recipient may be there.
+		// This is to resolve imcompatility until we fully migrate to the registration bucket.
 		if addr == nil {
-			return errors.Wrapf(ErrNotFoundFeeRecipient, "validator id %d", id)
+			bkt = tx.Bucket(registrationBucket)
+			enc := bkt.Get(bytesutil.Uint64ToBytesBigEndian(uint64(id)))
+			if enc == nil {
+				return errors.Wrapf(ErrNotFoundFeeRecipient, "validator id %d", id)
+			}
+			reg := &ethpb.ValidatorRegistrationV1{}
+			if err := decode(ctx, enc, reg); err != nil {
+				return err
+			}
+			addr = reg.FeeRecipient
 		}
 		return nil
 	})
@@ -482,6 +510,48 @@ func (s *Store) SaveFeeRecipientsByValidatorIDs(ctx context.Context, ids []types
 	})
 }
 
+// RegistrationByValidatorID returns the validator registration object for a validator id.
+// `ErrNotFoundFeeRecipient` is returned if the validator id is not found.
+func (s *Store) RegistrationByValidatorID(ctx context.Context, id types.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error) {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.RegistrationByValidatorID")
+	defer span.End()
+	reg := &ethpb.ValidatorRegistrationV1{}
+	err := s.db.View(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(registrationBucket)
+		enc := bkt.Get(bytesutil.Uint64ToBytesBigEndian(uint64(id)))
+		if enc == nil {
+			return errors.Wrapf(ErrNotFoundFeeRecipient, "validator id %d", id)
+		}
+		return decode(ctx, enc, reg)
+	})
+	return reg, err
+}
+
+// SaveRegistrationsByValidatorIDs saves the validator registrations for validator ids.
+// Error is returned if `ids` and `registrations` are not the same length.
+func (s *Store) SaveRegistrationsByValidatorIDs(ctx context.Context, ids []types.ValidatorIndex, regs []*ethpb.ValidatorRegistrationV1) error {
+	_, span := trace.StartSpan(ctx, "BeaconDB.SaveRegistrationsByValidatorIDs")
+	defer span.End()
+
+	if len(ids) != len(regs) {
+		return errors.New("ids and registrations must be the same length")
+	}
+
+	return s.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(registrationBucket)
+		for i, id := range ids {
+			enc, err := encode(ctx, regs[i])
+			if err != nil {
+				return err
+			}
+			if err := bkt.Put(bytesutil.Uint64ToBytesBigEndian(uint64(id)), enc); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}
+
 // blockRootsByFilter retrieves the block roots given the filter criteria.
 func blockRootsByFilter(ctx context.Context, tx *bolt.Tx, f *filters.QueryFilter) ([][]byte, error) {
 	ctx, span := trace.StartSpan(ctx, "BeaconDB.blockRootsByFilter")

beacon-chain/db/kv/blocks_test.go

@@ -693,4 +693,78 @@ func TestStore_FeeRecipientByValidatorID(t *testing.T) {
 	_, err = db.FeeRecipientByValidatorID(ctx, 3)
 	want := errors.Wrap(ErrNotFoundFeeRecipient, "validator id 3")
 	require.Equal(t, want.Error(), err.Error())
+
+	regs := []*ethpb.ValidatorRegistrationV1{
+		{
+			FeeRecipient: bytesutil.PadTo([]byte("a"), 20),
+			GasLimit:     1,
+			Timestamp:    2,
+			Pubkey:       bytesutil.PadTo([]byte("b"), 48),
+		}}
+	require.NoError(t, db.SaveRegistrationsByValidatorIDs(ctx, []types.ValidatorIndex{3}, regs))
+	f, err = db.FeeRecipientByValidatorID(ctx, 3)
+	require.NoError(t, err)
+	require.Equal(t, common.Address{'a'}, f)
+
+	_, err = db.FeeRecipientByValidatorID(ctx, 4)
+	want = errors.Wrap(ErrNotFoundFeeRecipient, "validator id 4")
+	require.Equal(t, want.Error(), err.Error())
+}
+
+func TestStore_RegistrationsByValidatorID(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	ids := []types.ValidatorIndex{0, 0, 0}
+	regs := []*ethpb.ValidatorRegistrationV1{{}, {}, {}, {}}
+	require.ErrorContains(t, "ids and registrations must be the same length", db.SaveRegistrationsByValidatorIDs(ctx, ids, regs))
+
+	ids = []types.ValidatorIndex{0, 1, 2}
+	regs = []*ethpb.ValidatorRegistrationV1{
+		{
+			FeeRecipient: bytesutil.PadTo([]byte("a"), 20),
+			GasLimit:     1,
+			Timestamp:    2,
+			Pubkey:       bytesutil.PadTo([]byte("b"), 48),
+		},
+		{
+			FeeRecipient: bytesutil.PadTo([]byte("c"), 20),
+			GasLimit:     3,
+			Timestamp:    4,
+			Pubkey:       bytesutil.PadTo([]byte("d"), 48),
+		},
+		{
+			FeeRecipient: bytesutil.PadTo([]byte("e"), 20),
+			GasLimit:     5,
+			Timestamp:    6,
+			Pubkey:       bytesutil.PadTo([]byte("f"), 48),
+		},
+	}
+	require.NoError(t, db.SaveRegistrationsByValidatorIDs(ctx, ids, regs))
+	f, err := db.RegistrationByValidatorID(ctx, 0)
+	require.NoError(t, err)
+	require.DeepEqual(t, &ethpb.ValidatorRegistrationV1{
+		FeeRecipient: bytesutil.PadTo([]byte("a"), 20),
+		GasLimit:     1,
+		Timestamp:    2,
+		Pubkey:       bytesutil.PadTo([]byte("b"), 48),
+	}, f)
+	f, err = db.RegistrationByValidatorID(ctx, 1)
+	require.NoError(t, err)
+	require.DeepEqual(t, &ethpb.ValidatorRegistrationV1{
+		FeeRecipient: bytesutil.PadTo([]byte("c"), 20),
+		GasLimit:     3,
+		Timestamp:    4,
+		Pubkey:       bytesutil.PadTo([]byte("d"), 48),
+	}, f)
+	f, err = db.RegistrationByValidatorID(ctx, 2)
+	require.NoError(t, err)
+	require.DeepEqual(t, &ethpb.ValidatorRegistrationV1{
+		FeeRecipient: bytesutil.PadTo([]byte("e"), 20),
+		GasLimit:     5,
+		Timestamp:    6,
+		Pubkey:       bytesutil.PadTo([]byte("f"), 48),
+	}, f)
+	_, err = db.RegistrationByValidatorID(ctx, 3)
+	want := errors.Wrap(ErrNotFoundFeeRecipient, "validator id 3")
+	require.Equal(t, want.Error(), err.Error())
 }

beacon-chain/db/kv/encoding.go

@@ -70,6 +70,8 @@ func isSSZStorageFormat(obj interface{}) bool {
 		return true
 	case *ethpb.VoluntaryExit:
 		return true
+	case *ethpb.ValidatorRegistrationV1:
+		return true
 	default:
 		return false
 	}

beacon-chain/db/kv/kv.go

@@ -192,6 +192,7 @@ func NewKVStore(ctx context.Context, dirPath string, config *Config) (*Store, er
 			migrationsBucket,
 
 			feeRecipientBucket,
+			registrationBucket,
 		)
 	}); err != nil {
 		log.WithField("elapsed", time.Since(start)).Error("Failed to update db and create buckets")

beacon-chain/db/kv/migration_state_validators.go

@@ -7,10 +7,11 @@ import (
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/golang/snappy"
-	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/config/features"
+	"github.com/prysmaticlabs/prysm/encoding/ssz/detect"
 	"github.com/prysmaticlabs/prysm/monitoring/progress"
 	v1alpha1 "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/schollz/progressbar/v3"
 	bolt "go.etcd.io/bbolt"
 )
 
@@ -83,104 +84,10 @@ func migrateStateValidators(ctx context.Context, db *bolt.DB) error {
 	// prepare the progress bar with the total count of the keys to migrate
 	bar := progress.InitializeProgressBar(len(keys), "Migrating state validators to new schema.")
 
-	batchNo := 0
 	for batchIndex := 0; batchIndex < len(keys); batchIndex += batchSize {
-		if err := db.Update(func(tx *bolt.Tx) error {
-			//create the source and destination buckets
-			stateBkt := tx.Bucket(stateBucket)
-			if stateBkt == nil {
-				return nil
-			}
-			valBkt := tx.Bucket(stateValidatorsBucket)
-			if valBkt == nil {
-				return nil
-			}
-			indexBkt := tx.Bucket(blockRootValidatorHashesBucket)
-			if indexBkt == nil {
-				return nil
-			}
-
-			// migrate the key values for this batch
-			cursor := stateBkt.Cursor()
-			count := 0
-			index := batchIndex
-			for _, v := cursor.Seek(keys[index]); count < batchSize && index < len(keys); _, v = cursor.Next() {
-				enc, err := snappy.Decode(nil, v)
-				if err != nil {
-					return err
-				}
-				switch {
-				case hasAltairKey(enc):
-					protoState := &v1alpha1.BeaconStateAltair{}
-					if err := protoState.UnmarshalSSZ(enc[len(altairKey):]); err != nil {
-						return errors.Wrap(err, "failed to unmarshal encoding for altair")
-					}
-					// no validators in state to migrate
-					if len(protoState.Validators) == 0 {
-						return fmt.Errorf("no validator entries in state key 0x%s", hexutil.Encode(keys[index]))
-					}
-					validatorKeys, insertErr := insertValidatorHashes(ctx, protoState.Validators, valBkt)
-					if insertErr != nil {
-						return insertErr
-					}
-					// add the validator entry keys for a given block root.
-					compValidatorKeys := snappy.Encode(nil, validatorKeys)
-					idxErr := indexBkt.Put(keys[index], compValidatorKeys)
-					if idxErr != nil {
-						return idxErr
-					}
-					// zero the validator entries in BeaconState object .
-					protoState.Validators = make([]*v1alpha1.Validator, 0)
-					rawObj, err := protoState.MarshalSSZ()
-					if err != nil {
-						return err
-					}
-					stateBytes := snappy.Encode(nil, append(altairKey, rawObj...))
-					if stateErr := stateBkt.Put(keys[index], stateBytes); stateErr != nil {
-						return stateErr
-					}
-				default:
-					protoState := &v1alpha1.BeaconState{}
-					if err := protoState.UnmarshalSSZ(enc); err != nil {
-						return errors.Wrap(err, "failed to unmarshal encoding for phase0")
-					}
-					// no validators in state to migrate
-					if len(protoState.Validators) == 0 {
-						return fmt.Errorf("no validator entries in state key 0x%s", hexutil.Encode(keys[index]))
-					}
-					validatorKeys, insertErr := insertValidatorHashes(ctx, protoState.Validators, valBkt)
-					if insertErr != nil {
-						return insertErr
-					}
-					// add the validator entry keys for a given block root.
-					compValidatorKeys := snappy.Encode(nil, validatorKeys)
-					idxErr := indexBkt.Put(keys[index], compValidatorKeys)
-					if idxErr != nil {
-						return idxErr
-					}
-					// zero the validator entries in BeaconState object .
-					protoState.Validators = make([]*v1alpha1.Validator, 0)
-					stateBytes, err := encode(ctx, protoState)
-					if err != nil {
-						return err
-					}
-					if stateErr := stateBkt.Put(keys[index], stateBytes); stateErr != nil {
-						return stateErr
-					}
-				}
-				count++
-				index++
-
-				if barErr := bar.Add(1); barErr != nil {
-					return barErr
-				}
-			}
-
-			return nil
-		}); err != nil {
+		if err := db.Update(performValidatorStateMigration(ctx, bar, batchIndex, keys)); err != nil {
 			return err
 		}
-		batchNo++
 	}
 
 	// set the migration entry to done
@@ -197,6 +104,87 @@ func migrateStateValidators(ctx context.Context, db *bolt.DB) error {
 	return nil
 }
 
+func performValidatorStateMigration(ctx context.Context, bar *progressbar.ProgressBar, batchIndex int, keys [][]byte) func(tx *bolt.Tx) error {
+	return func(tx *bolt.Tx) error {
+		//create the source and destination buckets
+		stateBkt := tx.Bucket(stateBucket)
+		if stateBkt == nil {
+			return nil
+		}
+		valBkt := tx.Bucket(stateValidatorsBucket)
+		if valBkt == nil {
+			return nil
+		}
+		indexBkt := tx.Bucket(blockRootValidatorHashesBucket)
+		if indexBkt == nil {
+			return nil
+		}
+
+		// migrate the key values for this batch
+		cursor := stateBkt.Cursor()
+		count := 0
+		index := batchIndex
+		for _, v := cursor.Seek(keys[index]); count < batchSize && index < len(keys); _, v = cursor.Next() {
+			enc, err := snappy.Decode(nil, v)
+			if err != nil {
+				return err
+			}
+			item := enc
+			if hasAltairKey(item) {
+				item = item[len(altairKey):]
+			}
+			detector, err := detect.FromState(item)
+			if err != nil {
+				return err
+			}
+			beaconState, err := detector.UnmarshalBeaconState(item)
+			if err != nil {
+				return err
+			}
+			// no validators in state to migrate
+			if beaconState.NumValidators() == 0 {
+				return fmt.Errorf("no validator entries in state key 0x%s", hexutil.Encode(keys[index]))
+			}
+			vals := beaconState.Validators()
+			validatorKeys, insertErr := insertValidatorHashes(ctx, vals, valBkt)
+			if insertErr != nil {
+				return insertErr
+			}
+			// add the validator entry keys for a given block root.
+			compValidatorKeys := snappy.Encode(nil, validatorKeys)
+			idxErr := indexBkt.Put(keys[index], compValidatorKeys)
+			if idxErr != nil {
+				return idxErr
+			}
+			// zero the validator entries in BeaconState object .
+			if err := beaconState.SetValidators(make([]*v1alpha1.Validator, 0)); err != nil {
+				return err
+			}
+			rawObj, err := beaconState.MarshalSSZ()
+			if err != nil {
+				return err
+			}
+			var stateBytes []byte
+			if hasAltairKey(enc) {
+				stateBytes = snappy.Encode(nil, append(altairKey, rawObj...))
+			} else {
+				stateBytes = snappy.Encode(nil, rawObj)
+			}
+			if stateErr := stateBkt.Put(keys[index], stateBytes); stateErr != nil {
+				return stateErr
+			}
+			count++
+			index++
+
+			if barErr := bar.Add(1); barErr != nil {
+				return barErr
+			}
+		}
+
+		return nil
+	}
+}
+
 func stateBucketKeys(stateBucket *bolt.Bucket) ([][]byte, error) {
 	var keys [][]byte
 	if err := stateBucket.ForEach(func(pubKey, v []byte) error {

beacon-chain/db/kv/migration_state_validators_test.go

@@ -10,6 +10,7 @@ import (
 	v1 "github.com/prysmaticlabs/prysm/beacon-chain/state/v1"
 	v2 "github.com/prysmaticlabs/prysm/beacon-chain/state/v2"
 	"github.com/prysmaticlabs/prysm/config/features"
+	"github.com/prysmaticlabs/prysm/config/params"
 	v1alpha1 "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
@@ -291,6 +292,12 @@ func Test_migrateAltairStateValidators(t *testing.T) {
 			vals := validators(10)
 			blockRoot := [32]byte{'A'}
 			st, _ := util.DeterministicGenesisStateAltair(t, 20)
+			err := st.SetFork(&v1alpha1.Fork{
+				PreviousVersion: params.BeaconConfig().GenesisForkVersion,
+				CurrentVersion:  params.BeaconConfig().AltairForkVersion,
+				Epoch:           0,
+			})
+			require.NoError(t, err)
 			assert.NoError(t, st.SetSlot(100))
 			assert.NoError(t, st.SetValidators(vals))
 			assert.NoError(t, dbStore.SaveState(context.Background(), st, blockRoot))

beacon-chain/db/kv/schema.go

@@ -19,6 +19,7 @@ var (
 	powchainBucket          = []byte("powchain")
 	stateValidatorsBucket   = []byte("state-validators")
 	feeRecipientBucket      = []byte("fee-recipient")
+	registrationBucket      = []byte("registration")
 
 	// Deprecated: This bucket was migrated in PR 6461. Do not use, except for migrations.
 	slotsHasObjectBucket = []byte("slots-has-objects")

beacon-chain/forkchoice/BUILD.bazel

@@ -4,6 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "doc.go",
+        "error.go",
         "interfaces.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice",
@@ -16,5 +17,6 @@ go_library(
         "//config/fieldparams:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/forkchoice/doubly-linked-tree/BUILD.bazel

@@ -20,6 +20,8 @@ go_library(
         "//testing/spectest:__subpackages__",
     ],
     deps = [
+        "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/forkchoice:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
@@ -49,13 +51,16 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/forkchoice:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//consensus-types/wrapper:go_default_library",
         "//crypto/hash: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",
     ],
 )

beacon-chain/forkchoice/doubly-linked-tree/forkchoice.go

@@ -5,6 +5,9 @@ import (
 	"fmt"
 
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
@@ -379,3 +382,74 @@ func (f *ForkChoice) UpdateFinalizedCheckpoint(fc *pbrpc.Checkpoint) error {
 	f.store.finalizedEpoch = fc.Epoch
 	return nil
 }
+
+// CommonAncestorRoot returns the common ancestor root between the two block roots r1 and r2.
+func (f *ForkChoice) CommonAncestorRoot(ctx context.Context, r1 [32]byte, r2 [32]byte) ([32]byte, error) {
+	ctx, span := trace.StartSpan(ctx, "doublelinkedtree.CommonAncestorRoot")
+	defer span.End()
+
+	// Do nothing if the input roots are the same.
+	if r1 == r2 {
+		return r1, nil
+	}
+
+	f.store.nodesLock.RLock()
+	defer f.store.nodesLock.RUnlock()
+
+	n1, ok := f.store.nodeByRoot[r1]
+	if !ok || n1 == nil {
+		return [32]byte{}, ErrNilNode
+	}
+	n2, ok := f.store.nodeByRoot[r2]
+	if !ok || n2 == nil {
+		return [32]byte{}, ErrNilNode
+	}
+
+	for {
+		if ctx.Err() != nil {
+			return [32]byte{}, ctx.Err()
+		}
+		if n1.slot > n2.slot {
+			n1 = n1.parent
+			// Reaches the end of the tree and unable to find common ancestor.
+			if n1 == nil {
+				return [32]byte{}, forkchoice.ErrUnknownCommonAncestor
+			}
+		} else {
+			n2 = n2.parent
+			// Reaches the end of the tree and unable to find common ancestor.
+			if n2 == nil {
+				return [32]byte{}, forkchoice.ErrUnknownCommonAncestor
+			}
+		}
+		if n1 == n2 {
+			return n1.root, nil
+		}
+	}
+}
+
+// InsertOptimisticChain inserts all nodes corresponding to blocks in the slice
+// `blocks`. This slice must be ordered from parent to child. It includes all
+// blocks **except** the first one. All blocks are assumed to be a strict chain
+// where blocks[i].Parent = blocks[i+1]. Also we assume that the parent of the
+// last block in this list is already included in forkchoice store.
+func (f *ForkChoice) InsertOptimisticChain(ctx context.Context, chain []*forkchoicetypes.BlockAndCheckpoints) error {
+	if len(chain) == 0 {
+		return nil
+	}
+	for i := len(chain) - 1; i > 0; i-- {
+		b := chain[i].Block
+		r := bytesutil.ToBytes32(chain[i-1].Block.ParentRoot())
+		parentRoot := bytesutil.ToBytes32(b.ParentRoot())
+		payloadHash, err := blocks.GetBlockPayloadHash(b)
+		if err != nil {
+			return err
+		}
+		if err := f.store.insert(ctx,
+			b.Slot(), r, parentRoot, payloadHash,
+			chain[i].JustifiedEpoch, chain[i].FinalizedEpoch); err != nil {
+			return err
+		}
+	}
+	return nil
+}

beacon-chain/forkchoice/doubly-linked-tree/forkchoice_test.go

@@ -5,13 +5,17 @@ import (
 	"encoding/binary"
 	"testing"
 
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
 	"github.com/prysmaticlabs/prysm/crypto/hash"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 )
 
 func TestForkChoice_UpdateBalancesPositiveChange(t *testing.T) {
@@ -251,3 +255,191 @@ func TestStore_UpdateCheckpoints(t *testing.T) {
 	require.Equal(t, f.store.justifiedEpoch, jc.Epoch)
 	require.Equal(t, f.store.finalizedEpoch, fc.Epoch)
 }
+
+func TestStore_CommonAncestor(t *testing.T) {
+	ctx := context.Background()
+	f := setup(0, 0)
+
+	//  /-- b -- d -- e
+	// a
+	//  \-- c -- f
+	//        \-- g
+	//        \ -- h -- i -- j
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 0, [32]byte{'a'}, params.BeaconConfig().ZeroHash, [32]byte{'A'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 1, [32]byte{'b'}, [32]byte{'a'}, [32]byte{'B'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 2, [32]byte{'c'}, [32]byte{'a'}, [32]byte{'C'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 3, [32]byte{'d'}, [32]byte{'b'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 4, [32]byte{'e'}, [32]byte{'d'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 5, [32]byte{'f'}, [32]byte{'c'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 6, [32]byte{'g'}, [32]byte{'c'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 7, [32]byte{'h'}, [32]byte{'c'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 8, [32]byte{'i'}, [32]byte{'h'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 9, [32]byte{'j'}, [32]byte{'i'}, [32]byte{}, 1, 1))
+
+	tests := []struct {
+		name     string
+		r1       [32]byte
+		r2       [32]byte
+		wantRoot [32]byte
+	}{
+		{
+			name:     "Common ancestor between c and b is a",
+			r1:       [32]byte{'c'},
+			r2:       [32]byte{'b'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between c and d is a",
+			r1:       [32]byte{'c'},
+			r2:       [32]byte{'d'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between c and e is a",
+			r1:       [32]byte{'c'},
+			r2:       [32]byte{'e'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between g and f is c",
+			r1:       [32]byte{'g'},
+			r2:       [32]byte{'f'},
+			wantRoot: [32]byte{'c'},
+		},
+		{
+			name:     "Common ancestor between f and h is c",
+			r1:       [32]byte{'f'},
+			r2:       [32]byte{'h'},
+			wantRoot: [32]byte{'c'},
+		},
+		{
+			name:     "Common ancestor between g and h is c",
+			r1:       [32]byte{'g'},
+			r2:       [32]byte{'h'},
+			wantRoot: [32]byte{'c'},
+		},
+		{
+			name:     "Common ancestor between b and h is a",
+			r1:       [32]byte{'b'},
+			r2:       [32]byte{'h'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between e and h is a",
+			r1:       [32]byte{'e'},
+			r2:       [32]byte{'h'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between i and f is c",
+			r1:       [32]byte{'i'},
+			r2:       [32]byte{'f'},
+			wantRoot: [32]byte{'c'},
+		},
+		{
+			name:     "Common ancestor between e and h is a",
+			r1:       [32]byte{'j'},
+			r2:       [32]byte{'g'},
+			wantRoot: [32]byte{'c'},
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			gotRoot, err := f.CommonAncestorRoot(ctx, tc.r1, tc.r2)
+			require.NoError(t, err)
+			require.Equal(t, tc.wantRoot, gotRoot)
+		})
+	}
+
+	// a -- b -- c -- d
+	f = setup(0, 0)
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 0, [32]byte{'a'}, params.BeaconConfig().ZeroHash, [32]byte{'A'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 1, [32]byte{'b'}, [32]byte{'a'}, [32]byte{'B'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 2, [32]byte{'c'}, [32]byte{'b'}, [32]byte{'C'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 3, [32]byte{'d'}, [32]byte{'c'}, [32]byte{}, 1, 1))
+	tests = []struct {
+		name     string
+		r1       [32]byte
+		r2       [32]byte
+		wantRoot [32]byte
+	}{
+		{
+			name:     "Common ancestor between a and b is a",
+			r1:       [32]byte{'a'},
+			r2:       [32]byte{'b'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between b and d is b",
+			r1:       [32]byte{'d'},
+			r2:       [32]byte{'b'},
+			wantRoot: [32]byte{'b'},
+		},
+		{
+			name:     "Common ancestor between d and a is a",
+			r1:       [32]byte{'d'},
+			r2:       [32]byte{'a'},
+			wantRoot: [32]byte{'a'},
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			gotRoot, err := f.CommonAncestorRoot(ctx, tc.r1, tc.r2)
+			require.NoError(t, err)
+			require.Equal(t, tc.wantRoot, gotRoot)
+		})
+	}
+
+	// Equal inputs should return the same root.
+	r, err := f.CommonAncestorRoot(ctx, [32]byte{'b'}, [32]byte{'b'})
+	require.NoError(t, err)
+	require.Equal(t, [32]byte{'b'}, r)
+	// Requesting finalized root (last node) should return the same root.
+	r, err = f.CommonAncestorRoot(ctx, [32]byte{'a'}, [32]byte{'a'})
+	require.NoError(t, err)
+	require.Equal(t, [32]byte{'a'}, r)
+	// Requesting unknown root
+	_, err = f.CommonAncestorRoot(ctx, [32]byte{'a'}, [32]byte{'z'})
+	require.ErrorIs(t, err, ErrNilNode)
+	_, err = f.CommonAncestorRoot(ctx, [32]byte{'z'}, [32]byte{'a'})
+	require.ErrorIs(t, err, ErrNilNode)
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 100, [32]byte{'y'}, [32]byte{'z'}, [32]byte{}, 1, 1))
+	// broken link
+	_, err = f.CommonAncestorRoot(ctx, [32]byte{'y'}, [32]byte{'a'})
+	require.ErrorIs(t, err, forkchoice.ErrUnknownCommonAncestor)
+}
+
+func TestStore_InsertOptimisticChain(t *testing.T) {
+	f := setup(1, 1)
+	blks := make([]*forkchoicetypes.BlockAndCheckpoints, 0)
+	blk := util.NewBeaconBlock()
+	blk.Block.Slot = 1
+	pr := [32]byte{}
+	blk.Block.ParentRoot = pr[:]
+	root, err := blk.Block.HashTreeRoot()
+	require.NoError(t, err)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
+	require.NoError(t, err)
+	blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(), JustifiedEpoch: 1,
+		FinalizedEpoch: 1})
+	for i := uint64(2); i < 11; i++ {
+		blk := util.NewBeaconBlock()
+		blk.Block.Slot = types.Slot(i)
+		copiedRoot := root
+		blk.Block.ParentRoot = copiedRoot[:]
+		wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(), JustifiedEpoch: 1,
+			FinalizedEpoch: 1})
+		root, err = blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+	}
+	args := make([]*forkchoicetypes.BlockAndCheckpoints, 10)
+	for i := 0; i < len(blks); i++ {
+		args[i] = blks[10-i-1]
+	}
+	require.NoError(t, f.InsertOptimisticChain(context.Background(), args))
+
+	f = setup(1, 1)
+	require.NoError(t, f.InsertOptimisticChain(context.Background(), args[2:]))
+}

beacon-chain/forkchoice/doubly-linked-tree/proposer_boost_test.go

@@ -162,25 +162,25 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		//
 		// (A: 30) -> (B: 20) -> (C: 10)
 		//
-		// The boost adds 14 to the weight, so if C is boosted, we would have
+		// The boost adds 8 to the weight, so if C is boosted, we would have
 		//
-		// (A: 44) -> (B: 34) -> (C: 24)
+		// (A: 38) -> (B: 28) -> (C: 18)
 		//
 		// In this case, we have a small fork:
 		//
-		// (A: 54) -> (B: 44) -> (C: 10)
-		//                   \_->(D: 24)
+		// (A: 48) -> (B: 38) -> (C: 10)
+		//                   \_->(D: 18)
 		//
 		// So B has its own weight, 10, and the sum of both C and D. That's why we see weight 54 in the
 		// middle instead of the normal progression of (54 -> 44 -> 24).
 		node1 := f.store.nodeByRoot[indexToHash(1)]
-		require.Equal(t, node1.weight, uint64(54))
+		require.Equal(t, node1.weight, uint64(48))
 		node2 := f.store.nodeByRoot[indexToHash(2)]
-		require.Equal(t, node2.weight, uint64(44))
+		require.Equal(t, node2.weight, uint64(38))
 		node3 := f.store.nodeByRoot[indexToHash(3)]
 		require.Equal(t, node3.weight, uint64(10))
 		node4 := f.store.nodeByRoot[indexToHash(4)]
-		require.Equal(t, node4.weight, uint64(24))
+		require.Equal(t, node4.weight, uint64(18))
 
 		// Regression: process attestations for C, check that it
 		// becomes head, we need two attestations to have C.weight = 30 > 24 = D.weight
@@ -254,6 +254,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		// The maliciously withheld block has one vote.
 		votes := []uint64{1}
 		f.ProcessAttestation(ctx, votes, maliciouslyWithheldBlock, fEpoch)
+		// The honest block has one vote.
+		votes = []uint64{2}
+		f.ProcessAttestation(ctx, votes, honestBlock, fEpoch)
 
 		// Ensure the head is STILL C, the honest block, as the honest block had proposer boost.
 		r, err = f.Head(ctx, zeroHash, balances)
@@ -427,6 +430,8 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		assert.Equal(t, c, r, "Expected C to remain the head")
 
 		// Block D receives the boost.
+		votes = []uint64{2}
+		f.ProcessAttestation(ctx, votes, d, fEpoch)
 		args = &forkchoicetypes.ProposerBoostRootArgs{
 			BlockRoot:       d,
 			BlockSlot:       dSlot,
@@ -536,9 +541,9 @@ func TestForkChoice_computeProposerBoostScore(t *testing.T) {
 		// With a committee size of num validators (64) / slots per epoch (32) == 2.
 		// we then have a committee weight of avg balance * committee size = 10 * 2 = 20.
 		// The score then becomes 10 * PROPOSER_SCORE_BOOST // 100, which is
-		// 20 * 70 / 100 = 14.
+		// 20 * 40 / 100 = 8.
 		score, err := computeProposerBoostScore(validatorBalances)
 		require.NoError(t, err)
-		require.Equal(t, uint64(14), score)
+		require.Equal(t, uint64(8), score)
 	})
 }

beacon-chain/forkchoice/error.go

@@ -0,0 +1,5 @@
+package forkchoice
+
+import "github.com/pkg/errors"
+
+var ErrUnknownCommonAncestor = errors.New("unknown common ancestor")

beacon-chain/forkchoice/interfaces.go

@@ -37,6 +37,7 @@ type BlockProcessor interface {
 		justifiedEpoch types.Epoch,
 		finalizedEpoch types.Epoch,
 	) error
+	InsertOptimisticChain(context.Context, []*forkchoicetypes.BlockAndCheckpoints) error
 }
 
 // AttestationProcessor processes the attestation that's used for accounting fork choice.
@@ -62,6 +63,7 @@ type Getter interface {
 	ProposerBoost() [fieldparams.RootLength]byte
 	HasParent(root [32]byte) bool
 	AncestorRoot(ctx context.Context, root [32]byte, slot types.Slot) ([]byte, error)
+	CommonAncestorRoot(ctx context.Context, root1 [32]byte, root2 [32]byte) ([32]byte, error)
 	IsCanonical(root [32]byte) bool
 	FinalizedEpoch() types.Epoch
 	JustifiedEpoch() types.Epoch

beacon-chain/forkchoice/protoarray/BUILD.bazel

@@ -20,6 +20,8 @@ go_library(
         "//testing/spectest:__subpackages__",
     ],
     deps = [
+        "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/forkchoice:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
@@ -50,13 +52,16 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/forkchoice:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//consensus-types/wrapper:go_default_library",
         "//crypto/hash: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",
     ],
 )

beacon-chain/forkchoice/protoarray/proposer_boost_test.go

@@ -163,19 +163,19 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		//
 		// The boost adds 14 to the weight, so if C is boosted, we would have
 		//
-		// (A: 44) -> (B: 34) -> (C: 24)
+		// (A: 38) -> (B: 28) -> (C: 18)
 		//
 		// In this case, we have a small fork:
 		//
-		// (A: 54) -> (B: 44) -> (C: 10)
-		//				    \_->(D: 24)
+		// (A: 48) -> (B: 38) -> (C: 10)
+		//				    \_->(D: 18)
 		//
 		// So B has its own weight, 10, and the sum of both C and D. That's why we see weight 54 in the
-		// middle instead of the normal progression of (54 -> 44 -> 24).
-		require.Equal(t, f.store.nodes[1].weight, uint64(54))
-		require.Equal(t, f.store.nodes[2].weight, uint64(44))
+		// middle instead of the normal progression of (48 -> 38 -> 18).
+		require.Equal(t, f.store.nodes[1].weight, uint64(48))
+		require.Equal(t, f.store.nodes[2].weight, uint64(38))
 		require.Equal(t, f.store.nodes[3].weight, uint64(10))
-		require.Equal(t, f.store.nodes[4].weight, uint64(24))
+		require.Equal(t, f.store.nodes[4].weight, uint64(18))
 
 		// Regression: process attestations for C, check that it
 		// becomes head, we need two attestations to have C.weight = 30 > 24 = D.weight
@@ -248,6 +248,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		// The maliciously withheld block has one vote.
 		votes := []uint64{1}
 		f.ProcessAttestation(ctx, votes, maliciouslyWithheldBlock, fEpoch)
+		// The honest block has one vote.
+		votes = []uint64{2}
+		f.ProcessAttestation(ctx, votes, honestBlock, fEpoch)
 
 		// Ensure the head is STILL C, the honest block, as the honest block had proposer boost.
 		r, err = f.Head(ctx, zeroHash, balances)
@@ -421,6 +424,8 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		assert.Equal(t, c, r, "Expected C to remain the head")
 
 		// Block D receives the boost.
+		votes = []uint64{2}
+		f.ProcessAttestation(ctx, votes, d, fEpoch)
 		args = &forkchoicetypes.ProposerBoostRootArgs{
 			BlockRoot:       d,
 			BlockSlot:       dSlot,
@@ -530,9 +535,9 @@ func TestForkChoice_computeProposerBoostScore(t *testing.T) {
 		// With a committee size of num validators (64) / slots per epoch (32) == 2.
 		// we then have a committee weight of avg balance * committee size = 10 * 2 = 20.
 		// The score then becomes 10 * PROPOSER_SCORE_BOOST // 100, which is
-		// 20 * 70 / 100 = 14.
+		// 20 * 40 / 100 = 8.
 		score, err := computeProposerBoostScore(validatorBalances)
 		require.NoError(t, err)
-		require.Equal(t, uint64(14), score)
+		require.Equal(t, uint64(8), score)
 	})
 }

beacon-chain/forkchoice/protoarray/store.go

@@ -6,6 +6,9 @@ import (
 	"fmt"
 
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	fieldparams "github.com/prysmaticlabs/prysm/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
@@ -195,6 +198,52 @@ func (f *ForkChoice) AncestorRoot(ctx context.Context, root [32]byte, slot types
 	return f.store.nodes[i].root[:], nil
 }
 
+// CommonAncestorRoot returns the common ancestor root between the two block roots r1 and r2.
+func (f *ForkChoice) CommonAncestorRoot(ctx context.Context, r1 [32]byte, r2 [32]byte) ([32]byte, error) {
+	ctx, span := trace.StartSpan(ctx, "protoArray.CommonAncestorRoot")
+	defer span.End()
+
+	// Do nothing if the two input roots are the same.
+	if r1 == r2 {
+		return r1, nil
+	}
+
+	i1, ok := f.store.nodesIndices[r1]
+	if !ok || i1 >= uint64(len(f.store.nodes)) {
+		return [32]byte{}, errInvalidNodeIndex
+	}
+
+	i2, ok := f.store.nodesIndices[r2]
+	if !ok || i2 >= uint64(len(f.store.nodes)) {
+		return [32]byte{}, errInvalidNodeIndex
+	}
+
+	for {
+		if ctx.Err() != nil {
+			return [32]byte{}, ctx.Err()
+		}
+		if i1 > i2 {
+			n1 := f.store.nodes[i1]
+			i1 = n1.parent
+			// Reaches the end of the tree and unable to find common ancestor.
+			if i1 >= uint64(len(f.store.nodes)) {
+				return [32]byte{}, forkchoice.ErrUnknownCommonAncestor
+			}
+		} else {
+			n2 := f.store.nodes[i2]
+			i2 = n2.parent
+			// Reaches the end of the tree and unable to find common ancestor.
+			if i2 >= uint64(len(f.store.nodes)) {
+				return [32]byte{}, forkchoice.ErrUnknownCommonAncestor
+			}
+		}
+		if i1 == i2 {
+			n1 := f.store.nodes[i1]
+			return n1.root, nil
+		}
+	}
+}
+
 // PruneThreshold of fork choice store.
 func (s *Store) PruneThreshold() uint64 {
 	return s.pruneThreshold
@@ -805,3 +854,26 @@ func (f *ForkChoice) UpdateFinalizedCheckpoint(fc *pbrpc.Checkpoint) error {
 	f.store.finalizedEpoch = fc.Epoch
 	return nil
 }
+
+// InsertOptimisticChain inserts all nodes corresponding to blocks in the slice
+// `blocks`. It includes all blocks **except** the first one.
+func (f *ForkChoice) InsertOptimisticChain(ctx context.Context, chain []*forkchoicetypes.BlockAndCheckpoints) error {
+	if len(chain) == 0 {
+		return nil
+	}
+	for i := len(chain) - 1; i > 0; i-- {
+		b := chain[i].Block
+		r := bytesutil.ToBytes32(chain[i-1].Block.ParentRoot())
+		parentRoot := bytesutil.ToBytes32(b.ParentRoot())
+		payloadHash, err := blocks.GetBlockPayloadHash(b)
+		if err != nil {
+			return err
+		}
+		if err := f.store.insert(ctx,
+			b.Slot(), r, parentRoot, payloadHash,
+			chain[i].JustifiedEpoch, chain[i].FinalizedEpoch); err != nil {
+			return err
+		}
+	}
+	return nil
+}

beacon-chain/forkchoice/protoarray/store_test.go

@@ -4,12 +4,16 @@ import (
 	"context"
 	"testing"
 
+	"github.com/prysmaticlabs/prysm/beacon-chain/forkchoice"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/config/params"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/consensus-types/wrapper"
 	"github.com/prysmaticlabs/prysm/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/testing/assert"
 	"github.com/prysmaticlabs/prysm/testing/require"
+	"github.com/prysmaticlabs/prysm/testing/util"
 )
 
 func TestStore_PruneThreshold(t *testing.T) {
@@ -560,6 +564,159 @@ func TestStore_PruneBranched(t *testing.T) {
 	}
 }
 
+func TestStore_CommonAncestor(t *testing.T) {
+	ctx := context.Background()
+	f := setup(0, 0)
+
+	//  /-- b -- d -- e
+	// a
+	//  \-- c -- f
+	//        \-- g
+	//        \ -- h -- i -- j
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 0, [32]byte{'a'}, params.BeaconConfig().ZeroHash, [32]byte{'A'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 1, [32]byte{'b'}, [32]byte{'a'}, [32]byte{'B'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 2, [32]byte{'c'}, [32]byte{'a'}, [32]byte{'C'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 3, [32]byte{'d'}, [32]byte{'b'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 4, [32]byte{'e'}, [32]byte{'d'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 5, [32]byte{'f'}, [32]byte{'c'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 6, [32]byte{'g'}, [32]byte{'c'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 7, [32]byte{'h'}, [32]byte{'c'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 8, [32]byte{'i'}, [32]byte{'h'}, [32]byte{}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 9, [32]byte{'j'}, [32]byte{'i'}, [32]byte{}, 1, 1))
+
+	tests := []struct {
+		name     string
+		r1       [32]byte
+		r2       [32]byte
+		wantRoot [32]byte
+	}{
+		{
+			name:     "Common ancestor between c and b is a",
+			r1:       [32]byte{'c'},
+			r2:       [32]byte{'b'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between c and d is a",
+			r1:       [32]byte{'c'},
+			r2:       [32]byte{'d'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between c and e is a",
+			r1:       [32]byte{'c'},
+			r2:       [32]byte{'e'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between g and f is c",
+			r1:       [32]byte{'g'},
+			r2:       [32]byte{'f'},
+			wantRoot: [32]byte{'c'},
+		},
+		{
+			name:     "Common ancestor between f and h is c",
+			r1:       [32]byte{'f'},
+			r2:       [32]byte{'h'},
+			wantRoot: [32]byte{'c'},
+		},
+		{
+			name:     "Common ancestor between g and h is c",
+			r1:       [32]byte{'g'},
+			r2:       [32]byte{'h'},
+			wantRoot: [32]byte{'c'},
+		},
+		{
+			name:     "Common ancestor between b and h is a",
+			r1:       [32]byte{'b'},
+			r2:       [32]byte{'h'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between e and h is a",
+			r1:       [32]byte{'e'},
+			r2:       [32]byte{'h'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between i and f is c",
+			r1:       [32]byte{'i'},
+			r2:       [32]byte{'f'},
+			wantRoot: [32]byte{'c'},
+		},
+		{
+			name:     "Common ancestor between e and h is a",
+			r1:       [32]byte{'j'},
+			r2:       [32]byte{'g'},
+			wantRoot: [32]byte{'c'},
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			gotRoot, err := f.CommonAncestorRoot(ctx, tc.r1, tc.r2)
+			require.NoError(t, err)
+			require.Equal(t, tc.wantRoot, gotRoot)
+		})
+	}
+
+	// a -- b -- c -- d
+	f = setup(0, 0)
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 0, [32]byte{'a'}, params.BeaconConfig().ZeroHash, [32]byte{'A'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 1, [32]byte{'b'}, [32]byte{'a'}, [32]byte{'B'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 2, [32]byte{'c'}, [32]byte{'b'}, [32]byte{'C'}, 1, 1))
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 3, [32]byte{'d'}, [32]byte{'c'}, [32]byte{}, 1, 1))
+	tests = []struct {
+		name     string
+		r1       [32]byte
+		r2       [32]byte
+		wantRoot [32]byte
+	}{
+		{
+			name:     "Common ancestor between a and b is a",
+			r1:       [32]byte{'a'},
+			r2:       [32]byte{'b'},
+			wantRoot: [32]byte{'a'},
+		},
+		{
+			name:     "Common ancestor between b and d is b",
+			r1:       [32]byte{'d'},
+			r2:       [32]byte{'b'},
+			wantRoot: [32]byte{'b'},
+		},
+		{
+			name:     "Common ancestor between d and a is a",
+			r1:       [32]byte{'d'},
+			r2:       [32]byte{'a'},
+			wantRoot: [32]byte{'a'},
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			gotRoot, err := f.CommonAncestorRoot(ctx, tc.r1, tc.r2)
+			require.NoError(t, err)
+			require.Equal(t, tc.wantRoot, gotRoot)
+		})
+	}
+
+	// Equal inputs should return the same root.
+	r, err := f.CommonAncestorRoot(ctx, [32]byte{'b'}, [32]byte{'b'})
+	require.NoError(t, err)
+	require.Equal(t, [32]byte{'b'}, r)
+	// Requesting finalized root (last node) should return the same root.
+	r, err = f.CommonAncestorRoot(ctx, [32]byte{'a'}, [32]byte{'a'})
+	require.NoError(t, err)
+	require.Equal(t, [32]byte{'a'}, r)
+	// Requesting unknown root
+	_, err = f.CommonAncestorRoot(ctx, [32]byte{'a'}, [32]byte{'z'})
+	require.ErrorIs(t, err, errInvalidNodeIndex)
+	_, err = f.CommonAncestorRoot(ctx, [32]byte{'z'}, [32]byte{'a'})
+	require.ErrorIs(t, err, errInvalidNodeIndex)
+	require.NoError(t, f.InsertOptimisticBlock(ctx, 100, [32]byte{'y'}, [32]byte{'z'}, [32]byte{}, 1, 1))
+	// broken link
+	_, err = f.CommonAncestorRoot(ctx, [32]byte{'y'}, [32]byte{'a'})
+	require.ErrorIs(t, err, forkchoice.ErrUnknownCommonAncestor)
+}
+
 func TestStore_LeadsToViableHead(t *testing.T) {
 	tests := []struct {
 		n              *Node
@@ -822,3 +979,38 @@ func TestStore_UpdateCheckpoints(t *testing.T) {
 	require.Equal(t, f.store.justifiedEpoch, jc.Epoch)
 	require.Equal(t, f.store.finalizedEpoch, fc.Epoch)
 }
+
+func TestStore_InsertOptimisticChain(t *testing.T) {
+	f := setup(1, 1)
+	blks := make([]*forkchoicetypes.BlockAndCheckpoints, 0)
+	blk := util.NewBeaconBlock()
+	blk.Block.Slot = 1
+	pr := [32]byte{}
+	blk.Block.ParentRoot = pr[:]
+	root, err := blk.Block.HashTreeRoot()
+	require.NoError(t, err)
+	wsb, err := wrapper.WrappedSignedBeaconBlock(blk)
+	require.NoError(t, err)
+	blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(), JustifiedEpoch: 1,
+		FinalizedEpoch: 1})
+	for i := uint64(2); i < 11; i++ {
+		blk := util.NewBeaconBlock()
+		blk.Block.Slot = types.Slot(i)
+		copiedRoot := root
+		blk.Block.ParentRoot = copiedRoot[:]
+		wsb, err = wrapper.WrappedSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		blks = append(blks, &forkchoicetypes.BlockAndCheckpoints{Block: wsb.Block(), JustifiedEpoch: 1,
+			FinalizedEpoch: 1})
+		root, err = blk.Block.HashTreeRoot()
+		require.NoError(t, err)
+	}
+	args := make([]*forkchoicetypes.BlockAndCheckpoints, 10)
+	for i := 0; i < len(blks); i++ {
+		args[i] = blks[10-i-1]
+	}
+	require.NoError(t, f.InsertOptimisticChain(context.Background(), args))
+
+	f = setup(1, 1)
+	require.NoError(t, f.InsertOptimisticChain(context.Background(), args[2:]))
+}

beacon-chain/forkchoice/types/BUILD.bazel

@@ -5,5 +5,8 @@ go_library(
     srcs = ["types.go"],
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/forkchoice/types",
     visibility = ["//visibility:public"],
-    deps = ["//consensus-types/primitives:go_default_library"],
+    deps = [
+        "//consensus-types/interfaces:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+    ],
 )

beacon-chain/forkchoice/types/types.go

@@ -1,6 +1,7 @@
 package types
 
 import (
+	"github.com/prysmaticlabs/prysm/consensus-types/interfaces"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 )
 
@@ -11,3 +12,10 @@ type ProposerBoostRootArgs struct {
 	CurrentSlot     types.Slot
 	SecondsIntoSlot uint64
 }
+
+// BlockAndCheckpoints to call the InsertOptimisticChain function
+type BlockAndCheckpoints struct {
+	Block          interfaces.BeaconBlock
+	JustifiedEpoch types.Epoch
+	FinalizedEpoch types.Epoch
+}

beacon-chain/node/BUILD.bazel

@@ -18,6 +18,7 @@ go_library(
         "//api/gateway:go_default_library",
         "//async/event:go_default_library",
         "//beacon-chain/blockchain:go_default_library",
+        "//beacon-chain/builder:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositcache:go_default_library",
         "//beacon-chain/db:go_default_library",

beacon-chain/node/config.go

@@ -129,6 +129,25 @@ func configureInteropConfig(cliCtx *cli.Context) error {
 }
 
 func configureExecutionSetting(cliCtx *cli.Context) error {
+	if cliCtx.IsSet(flags.TerminalTotalDifficultyOverride.Name) {
+		c := params.BeaconConfig()
+		c.TerminalTotalDifficulty = cliCtx.String(flags.TerminalTotalDifficultyOverride.Name)
+		log.WithField("terminal block difficult", c.TerminalTotalDifficulty).Warn("Terminal block difficult overridden")
+		params.OverrideBeaconConfig(c)
+	}
+	if cliCtx.IsSet(flags.TerminalBlockHashOverride.Name) {
+		c := params.BeaconConfig()
+		c.TerminalBlockHash = common.HexToHash(cliCtx.String(flags.TerminalBlockHashOverride.Name))
+		log.WithField("terminal block hash", c.TerminalBlockHash.Hex()).Warn("Terminal block hash overridden")
+		params.OverrideBeaconConfig(c)
+	}
+	if cliCtx.IsSet(flags.TerminalBlockHashActivationEpochOverride.Name) {
+		c := params.BeaconConfig()
+		c.TerminalBlockHashActivationEpoch = types.Epoch(cliCtx.Uint64(flags.TerminalBlockHashActivationEpochOverride.Name))
+		log.WithField("terminal block hash activation epoch", c.TerminalBlockHashActivationEpoch).Warn("Terminal block hash activation epoch overridden")
+		params.OverrideBeaconConfig(c)
+	}
+
 	if !cliCtx.IsSet(flags.SuggestedFeeRecipient.Name) {
 		return nil
 	}

beacon-chain/node/config_test.go

@@ -92,6 +92,13 @@ func TestConfigureExecutionSetting(t *testing.T) {
 	app := cli.App{}
 	set := flag.NewFlagSet("test", 0)
 	set.String(flags.SuggestedFeeRecipient.Name, "", "")
+	set.Uint64(flags.TerminalTotalDifficultyOverride.Name, 0, "")
+	set.String(flags.TerminalBlockHashOverride.Name, "", "")
+	set.Uint64(flags.TerminalBlockHashActivationEpochOverride.Name, 0, "")
+
+	require.NoError(t, set.Set(flags.TerminalTotalDifficultyOverride.Name, strconv.Itoa(100)))
+	require.NoError(t, set.Set(flags.TerminalBlockHashOverride.Name, "0xA"))
+	require.NoError(t, set.Set(flags.TerminalBlockHashActivationEpochOverride.Name, strconv.Itoa(200)))
 	require.NoError(t, set.Set(flags.SuggestedFeeRecipient.Name, "0xB"))
 	cliCtx := cli.NewContext(&app, set, nil)
 	err := configureExecutionSetting(cliCtx)
@@ -112,6 +119,10 @@ func TestConfigureExecutionSetting(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, common.HexToAddress("0xaAaAaAaaAaAaAaaAaAAAAAAAAaaaAaAaAaaAaaAa"), params.BeaconConfig().DefaultFeeRecipient)
 
+	assert.Equal(t, "100", params.BeaconConfig().TerminalTotalDifficulty)
+	assert.Equal(t, common.HexToHash("0xA"), params.BeaconConfig().TerminalBlockHash)
+	assert.Equal(t, types.Epoch(200), params.BeaconConfig().TerminalBlockHashActivationEpoch)
+
 }
 
 func TestConfigureNetwork(t *testing.T) {

beacon-chain/node/node.go

@@ -20,6 +20,7 @@ import (
 	apigateway "github.com/prysmaticlabs/prysm/api/gateway"
 	"github.com/prysmaticlabs/prysm/async/event"
 	"github.com/prysmaticlabs/prysm/beacon-chain/blockchain"
+	"github.com/prysmaticlabs/prysm/beacon-chain/builder"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache/depositcache"
 	"github.com/prysmaticlabs/prysm/beacon-chain/db"
@@ -76,6 +77,7 @@ const debugGrpcMaxMsgSize = 1 << 27
 type serviceFlagOpts struct {
 	blockchainFlagOpts []blockchain.Option
 	powchainFlagOpts   []powchain.Option
+	builderOpts        []builder.Option
 }
 
 // BeaconNode defines a struct that handles the services running a random beacon chain

beacon-chain/node/options.go

@@ -2,6 +2,7 @@ package node
 
 import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/blockchain"
+	"github.com/prysmaticlabs/prysm/beacon-chain/builder"
 	"github.com/prysmaticlabs/prysm/beacon-chain/powchain"
 )
 
@@ -23,3 +24,11 @@ func WithPowchainFlagOptions(opts []powchain.Option) Option {
 		return nil
 	}
 }
+
+// WithBuilderFlagOptions includes functional options for the builder service related to CLI flags.
+func WithBuilderFlagOptions(opts []builder.Option) Option {
+	return func(bn *BeaconNode) error {
+		bn.serviceFlagOpts.builderOpts = opts
+		return nil
+	}
+}

beacon-chain/powchain/block_reader.go

@@ -210,7 +210,7 @@ func (s *Service) retrieveHeaderInfo(ctx context.Context, bNum uint64) (*types.H
 			return nil, err
 		}
 		if blk == nil {
-			return nil, errors.New("header with the provided number does not exist")
+			return nil, errors.Errorf("header with the number %d does not exist", bNum)
 		}
 		if err := s.headerCache.AddHeader(blk); err != nil {
 			return nil, err

beacon-chain/powchain/engine_client.go

@@ -296,7 +296,7 @@ func handleRPCError(err error) error {
 		return nil
 	}
 	if isTimeout(err) {
-		return errors.Wrapf(ErrHTTPTimeout, "%s", err)
+		return ErrHTTPTimeout
 	}
 	e, ok := err.(rpc.Error)
 	if !ok {
@@ -307,7 +307,7 @@ func handleRPCError(err error) error {
 				"here https://docs.prylabs.network/docs/execution-node/authentication")
 			return fmt.Errorf("could not authenticate connection to execution client: %v", err)
 		}
-		return errors.Wrap(err, "got an unexpected error")
+		return errors.Wrapf(err, "got an unexpected error in JSON-RPC response")
 	}
 	switch e.ErrorCode() {
 	case -32700:
@@ -330,7 +330,7 @@ func handleRPCError(err error) error {
 		// Only -32000 status codes are data errors in the RPC specification.
 		errWithData, ok := err.(rpc.DataError)
 		if !ok {
-			return errors.Wrap(err, "got an unexpected error")
+			return errors.Wrapf(err, "got an unexpected error in JSON-RPC response")
 		}
 		return errors.Wrapf(ErrServer, "%v", errWithData.ErrorData())
 	default:

beacon-chain/powchain/metrics.go

@@ -16,14 +16,14 @@ var (
 	getPayloadLatency = promauto.NewHistogram(
 		prometheus.HistogramOpts{
 			Name:    "get_payload_v1_latency_milliseconds",
-			Help:    "Captures RPC latency for newPayloadV1 in milliseconds",
+			Help:    "Captures RPC latency for getPayloadV1 in milliseconds",
 			Buckets: []float64{1, 2, 5, 10, 20, 50, 100, 200, 500, 1000},
 		},
 	)
 	forkchoiceUpdatedLatency = promauto.NewHistogram(
 		prometheus.HistogramOpts{
 			Name:    "forkchoice_updated_v1_latency_milliseconds",
-			Help:    "Captures RPC latency for newPayloadV1 in milliseconds",
+			Help:    "Captures RPC latency for forkchoiceUpdatedV1 in milliseconds",
 			Buckets: []float64{1, 2, 5, 10, 20, 50, 100, 200, 500, 1000},
 		},
 	)

beacon-chain/powchain/service.go

@@ -369,12 +369,17 @@ func (s *Service) ETH1ConnectionErrors() []error {
 
 // refers to the latest eth1 block which follows the condition: eth1_timestamp +
 // SECONDS_PER_ETH1_BLOCK * ETH1_FOLLOW_DISTANCE <= current_unix_time
-func (s *Service) followedBlockHeight(_ context.Context) (uint64, error) {
-	latestValidBlock := uint64(0)
-	if s.latestEth1Data.BlockHeight > params.BeaconConfig().Eth1FollowDistance {
-		latestValidBlock = s.latestEth1Data.BlockHeight - params.BeaconConfig().Eth1FollowDistance
+func (s *Service) followedBlockHeight(ctx context.Context) (uint64, error) {
+	followTime := params.BeaconConfig().Eth1FollowDistance * params.BeaconConfig().SecondsPerETH1Block
+	latestBlockTime := uint64(0)
+	if s.latestEth1Data.BlockTime > followTime {
+		latestBlockTime = s.latestEth1Data.BlockTime - followTime
 	}
-	return latestValidBlock, nil
+	blk, err := s.BlockByTimestamp(ctx, latestBlockTime)
+	if err != nil {
+		return 0, err
+	}
+	return blk.Number.Uint64(), nil
 }
 
 func (s *Service) initDepositCaches(ctx context.Context, ctrs []*ethpb.DepositContainer) error {

beacon-chain/powchain/service_test.go

@@ -81,7 +81,8 @@ func (g *goodNotifier) StateFeed() *event.Feed {
 }
 
 type goodFetcher struct {
-	backend *backends.SimulatedBackend
+	backend     *backends.SimulatedBackend
+	blockNumMap map[uint64]*gethTypes.Header
 }
 
 func (_ *goodFetcher) Close() {}
@@ -104,12 +105,15 @@ func (g *goodFetcher) HeaderByHash(_ context.Context, hash common.Hash) (*gethTy
 }
 
 func (g *goodFetcher) HeaderByNumber(_ context.Context, number *big.Int) (*gethTypes.Header, error) {
-	if g.backend == nil {
+	if g.backend == nil && g.blockNumMap == nil {
 		return &gethTypes.Header{
 			Number: big.NewInt(15),
 			Time:   150,
 		}, nil
 	}
+	if g.blockNumMap != nil {
+		return g.blockNumMap[number.Uint64()], nil
+	}
 	var header *gethTypes.Header
 	if number == nil {
 		header = g.backend.Blockchain().CurrentHeader()
@@ -864,6 +868,28 @@ func TestService_CacheBlockHeaders(t *testing.T) {
 	assert.Equal(t, 5, rClient.numOfCalls)
 }
 
+func TestService_FollowBlock(t *testing.T) {
+	followTime := params.BeaconConfig().Eth1FollowDistance * params.BeaconConfig().SecondsPerETH1Block
+	followTime += 10000
+	bMap := make(map[uint64]*gethTypes.Header)
+	for i := uint64(3000); i > 0; i-- {
+		bMap[i] = &gethTypes.Header{
+			Number: big.NewInt(int64(i)),
+			Time:   followTime + (i * 40),
+		}
+	}
+	s := &Service{
+		cfg:             &config{eth1HeaderReqLimit: 1000},
+		eth1DataFetcher: &goodFetcher{blockNumMap: bMap},
+		headerCache:     newHeaderCache(),
+		latestEth1Data:  &ethpb.LatestETH1Data{BlockTime: (3000 * 40) + followTime, BlockHeight: 3000},
+	}
+	h, err := s.followedBlockHeight(context.Background())
+	assert.NoError(t, err)
+	// With a much higher blocktime, the follow height is respectively shortened.
+	assert.Equal(t, uint64(2283), h)
+}
+
 type slowRPCClient struct {
 	limit      int
 	numOfCalls int

beacon-chain/rpc/apimiddleware/custom_handlers.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -17,10 +18,15 @@ import (
 )
 
 const (
-	versionHeader     = "Eth-Consensus-Version"
-	grpcVersionHeader = "Grpc-metadata-Eth-Consensus-Version"
+	versionHeader        = "Eth-Consensus-Version"
+	grpcVersionHeader    = "Grpc-metadata-Eth-Consensus-Version"
+	jsonMediaType        = "application/json"
+	octetStreamMediaType = "application/octet-stream"
 )
 
+// match a number with optional decimals
+var priorityRegex = regexp.MustCompile(`q=(\d+(?:\.\d+)?)`)
+
 type sszConfig struct {
 	fileName     string
 	responseJson sszResponse
@@ -99,7 +105,12 @@ func handleGetSSZ(
 	req *http.Request,
 	config sszConfig,
 ) (handled bool) {
-	if !sszRequested(req) {
+	ssz, err := sszRequested(req)
+	if err != nil {
+		apimiddleware.WriteError(w, apimiddleware.InternalServerError(err), nil)
+		return true
+	}
+	if !ssz {
 		return false
 	}
 
@@ -193,17 +204,42 @@ func handlePostSSZ(
 	return true
 }
 
-func sszRequested(req *http.Request) bool {
-	accept, ok := req.Header["Accept"]
-	if !ok {
-		return false
+func sszRequested(req *http.Request) (bool, error) {
+	accept := req.Header.Values("Accept")
+	if len(accept) == 0 {
+		return false, nil
 	}
-	for _, v := range accept {
-		if v == "application/octet-stream" {
-			return true
+	types := strings.Split(accept[0], ",")
+	currentType, currentPriority := "", 0.0
+	for _, t := range types {
+		values := strings.Split(t, ";")
+		name := values[0]
+		if name != jsonMediaType && name != octetStreamMediaType {
+			continue
+		}
+		// no params specified
+		if len(values) == 1 {
+			priority := 1.0
+			if priority > currentPriority {
+				currentType, currentPriority = name, priority
+			}
+			continue
+		}
+		params := values[1]
+		match := priorityRegex.FindAllStringSubmatch(params, 1)
+		if len(match) != 1 {
+			continue
+		}
+		priority, err := strconv.ParseFloat(match[0][1], 32)
+		if err != nil {
+			return false, err
+		}
+		if priority > currentPriority {
+			currentType, currentPriority = name, priority
 		}
 	}
-	return false
+
+	return currentType == octetStreamMediaType, nil
 }
 
 func sszPosted(req *http.Request) bool {
@@ -214,7 +250,7 @@ func sszPosted(req *http.Request) bool {
 	if len(ct) != 1 {
 		return false
 	}
-	return ct[0] == "application/octet-stream"
+	return ct[0] == octetStreamMediaType
 }
 
 func prepareSSZRequestForProxying(m *apimiddleware.ApiProxyMiddleware, endpoint apimiddleware.Endpoint, req *http.Request) apimiddleware.ErrorJson {
@@ -252,7 +288,7 @@ func preparePostedSSZData(req *http.Request) apimiddleware.ErrorJson {
 	}
 	req.Body = io.NopCloser(bytes.NewBuffer(data))
 	req.ContentLength = int64(len(data))
-	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Content-Type", jsonMediaType)
 	return nil
 }
 
@@ -280,7 +316,7 @@ func writeSSZResponseHeaderAndBody(grpcResp *http.Response, w http.ResponseWrite
 		}
 	}
 	w.Header().Set("Content-Length", strconv.Itoa(len(respSsz)))
-	w.Header().Set("Content-Type", "application/octet-stream")
+	w.Header().Set("Content-Type", octetStreamMediaType)
 	w.Header().Set("Content-Disposition", "attachment; filename="+fileName)
 	w.Header().Set(versionHeader, respVersion)
 	if statusCodeHeader != "" {

beacon-chain/rpc/apimiddleware/custom_handlers_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -34,28 +35,88 @@ func (t testSSZResponseJson) SSZData() string {
 func TestSSZRequested(t *testing.T) {
 	t.Run("ssz_requested", func(t *testing.T) {
 		request := httptest.NewRequest("GET", "http://foo.example", nil)
-		request.Header["Accept"] = []string{"application/octet-stream"}
-		result := sszRequested(request)
+		request.Header["Accept"] = []string{octetStreamMediaType}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
 		assert.Equal(t, true, result)
 	})
 
-	t.Run("multiple_content_types", func(t *testing.T) {
+	t.Run("ssz_content_type_first", func(t *testing.T) {
 		request := httptest.NewRequest("GET", "http://foo.example", nil)
-		request.Header["Accept"] = []string{"application/json", "application/octet-stream"}
-		result := sszRequested(request)
+		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s", octetStreamMediaType, jsonMediaType)}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
 		assert.Equal(t, true, result)
 	})
 
+	t.Run("ssz_content_type_preferred_1", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request.Header["Accept"] = []string{fmt.Sprintf("%s;q=0.9,%s", jsonMediaType, octetStreamMediaType)}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
+		assert.Equal(t, true, result)
+	})
+
+	t.Run("ssz_content_type_preferred_2", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request.Header["Accept"] = []string{fmt.Sprintf("%s;q=0.95,%s;q=0.9", octetStreamMediaType, jsonMediaType)}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
+		assert.Equal(t, true, result)
+	})
+
+	t.Run("other_content_type_preferred", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s;q=0.9", jsonMediaType, octetStreamMediaType)}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
+		assert.Equal(t, false, result)
+	})
+
+	t.Run("other_params", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request.Header["Accept"] = []string{fmt.Sprintf("%s,%s;q=0.9,otherparam=xyz", jsonMediaType, octetStreamMediaType)}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
+		assert.Equal(t, false, result)
+	})
+
 	t.Run("no_header", func(t *testing.T) {
 		request := httptest.NewRequest("GET", "http://foo.example", nil)
-		result := sszRequested(request)
+		result, err := sszRequested(request)
+		require.NoError(t, err)
+		assert.Equal(t, false, result)
+	})
+
+	t.Run("empty_header", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request.Header["Accept"] = []string{}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
+		assert.Equal(t, false, result)
+	})
+
+	t.Run("empty_header_value", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request.Header["Accept"] = []string{""}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
 		assert.Equal(t, false, result)
 	})
 
 	t.Run("other_content_type", func(t *testing.T) {
 		request := httptest.NewRequest("GET", "http://foo.example", nil)
-		request.Header["Accept"] = []string{"application/json"}
-		result := sszRequested(request)
+		request.Header["Accept"] = []string{"application/other"}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
+		assert.Equal(t, false, result)
+	})
+
+	t.Run("garbage", func(t *testing.T) {
+		request := httptest.NewRequest("GET", "http://foo.example", nil)
+		request.Header["Accept"] = []string{"This is Sparta!!!"}
+		result, err := sszRequested(request)
+		require.NoError(t, err)
 		assert.Equal(t, false, result)
 	})
 }
@@ -82,7 +143,7 @@ func TestPreparePostedSszData(t *testing.T) {
 
 	preparePostedSSZData(request)
 	assert.Equal(t, int64(19), request.ContentLength)
-	assert.Equal(t, "application/json", request.Header.Get("Content-Type"))
+	assert.Equal(t, jsonMediaType, request.Header.Get("Content-Type"))
 }
 
 func TestSerializeMiddlewareResponseIntoSSZ(t *testing.T) {
@@ -138,7 +199,7 @@ func TestWriteSSZResponseHeaderAndBody(t *testing.T) {
 		v, ok = writer.Header()["Content-Type"]
 		require.Equal(t, true, ok, "header not found")
 		require.Equal(t, 1, len(v), "wrong number of header values")
-		assert.Equal(t, "application/octet-stream", v[0])
+		assert.Equal(t, octetStreamMediaType, v[0])
 		v, ok = writer.Header()["Content-Disposition"]
 		require.Equal(t, true, ok, "header not found")
 		require.Equal(t, 1, len(v), "wrong number of header values")

beacon-chain/rpc/apimiddleware/structs.go

@@ -550,7 +550,7 @@ type indexedAttestationJson struct {
 }
 
 type feeRecipientJson struct {
-	ValidatorIndex uint64 `json:"validator_index"`
+	ValidatorIndex string `json:"validator_index"`
 	FeeRecipient   string `json:"fee_recipient" hex:"true"`
 }
 

beacon-chain/rpc/eth/beacon/config_test.go

@@ -123,6 +123,9 @@ func TestGetSpec(t *testing.T) {
 	var daap [4]byte
 	copy(daap[:], []byte{'0', '0', '0', '7'})
 	config.DomainAggregateAndProof = daap
+	var dam [4]byte
+	copy(dam[:], []byte{'1', '0', '0', '0'})
+	config.DomainApplicationMask = dam
 
 	params.OverrideBeaconConfig(config)
 
@@ -130,7 +133,7 @@ func TestGetSpec(t *testing.T) {
 	resp, err := server.GetSpec(context.Background(), &emptypb.Empty{})
 	require.NoError(t, err)
 
-	assert.Equal(t, 98, len(resp.Data))
+	assert.Equal(t, 99, len(resp.Data))
 	for k, v := range resp.Data {
 		switch k {
 		case "CONFIG_NAME":
@@ -315,6 +318,8 @@ func TestGetSpec(t *testing.T) {
 			assert.Equal(t, "0x30303036", v)
 		case "DOMAIN_AGGREGATE_AND_PROOF":
 			assert.Equal(t, "0x30303037", v)
+		case "DOMAIN_APPLICATION_MASK":
+			assert.Equal(t, "0x31303030", v)
 		case "DOMAIN_SYNC_COMMITTEE":
 			assert.Equal(t, "0x07000000", v)
 		case "DOMAIN_SYNC_COMMITTEE_SELECTION_PROOF":
@@ -338,7 +343,7 @@ func TestGetSpec(t *testing.T) {
 		case "INACTIVITY_PENALTY_QUOTIENT_BELLATRIX":
 			assert.Equal(t, "16777216", v)
 		case "PROPOSER_SCORE_BOOST":
-			assert.Equal(t, "70", v)
+			assert.Equal(t, "40", v)
 		case "INTERVALS_PER_SLOT":
 			assert.Equal(t, "3", v)
 		case "SAFE_SLOTS_TO_IMPORT_OPTIMISTICALLY":

beacon-chain/rpc/prysm/v1alpha1/validator/proposer.go

@@ -187,3 +187,8 @@ func (vs *Server) computeStateRoot(ctx context.Context, block interfaces.SignedB
 	log.WithField("beaconStateRoot", fmt.Sprintf("%#x", root)).Debugf("Computed state root")
 	return root[:], nil
 }
+
+// SubmitValidatorRegistration submits validator registration.
+func (vs *Server) SubmitValidatorRegistration(context.Context, *ethpb.SignedValidatorRegistrationV1) (*emptypb.Empty, error) {
+	return &emptypb.Empty{}, nil
+}

beacon-chain/rpc/prysm/v1alpha1/validator/status.go

@@ -113,7 +113,7 @@ func (vs *Server) CheckDoppelGanger(ctx context.Context, req *ethpb.DoppelGanger
 
 	// Return early if we are in phase0.
 	if headState.Version() == version.Phase0 {
-		log.Info("Skipping goppelganger check for Phase 0")
+		log.Info("Skipping doppelganger check for Phase 0")
 
 		resp := &ethpb.DoppelGangerResponse{
 			Responses: []*ethpb.DoppelGangerResponse_ValidatorResponse{},

beacon-chain/state/fieldtrie/BUILD.bazel

@@ -29,6 +29,7 @@ go_test(
         "field_trie_test.go",
         "helpers_test.go",
     ],
+    data = glob(["testdata/**"]),
     embed = [":go_default_library"],
     deps = [
         "//beacon-chain/state/stateutil:go_default_library",

beacon-chain/state/fieldtrie/field_trie.go

@@ -10,6 +10,11 @@ import (
 	pmath "github.com/prysmaticlabs/prysm/math"
 )
 
+var (
+	ErrInvalidFieldTrie = errors.New("invalid field trie")
+	ErrEmptyFieldTrie   = errors.New("empty field trie")
+)
+
 // FieldTrie is the representation of the representative
 // trie of the particular field.
 type FieldTrie struct {
@@ -188,6 +193,12 @@ func (f *FieldTrie) CopyTrie() *FieldTrie {
 
 // TrieRoot returns the corresponding root of the trie.
 func (f *FieldTrie) TrieRoot() ([32]byte, error) {
+	if f.Empty() {
+		return [32]byte{}, ErrEmptyFieldTrie
+	}
+	if len(f.fieldLayers[len(f.fieldLayers)-1]) == 0 {
+		return [32]byte{}, ErrInvalidFieldTrie
+	}
 	switch f.dataType {
 	case types.BasicArray:
 		return *f.fieldLayers[len(f.fieldLayers)-1][0], nil

beacon-chain/state/fieldtrie/field_trie_test.go

@@ -27,6 +27,13 @@ func TestFieldTrie_NewTrie(t *testing.T) {
 	assert.Equal(t, root, newRoot)
 }
 
+func TestFieldTrie_NewTrie_NilElements(t *testing.T) {
+	trie, err := fieldtrie.NewFieldTrie(stateTypes.FieldIndex(5), stateTypes.BasicArray, nil, 8234)
+	require.NoError(t, err)
+	_, err = trie.TrieRoot()
+	require.ErrorIs(t, err, fieldtrie.ErrEmptyFieldTrie)
+}
+
 func TestFieldTrie_RecomputeTrie(t *testing.T) {
 	newState, _ := util.DeterministicGenesisState(t, 32)
 	// 10 represents the enum value of validators
@@ -77,3 +84,27 @@ func TestFieldTrie_CopyTrieImmutable(t *testing.T) {
 		t.Errorf("Wanted roots to be different, but they are the same: %#x", root)
 	}
 }
+
+func FuzzFieldTrie(f *testing.F) {
+	newState, _ := util.DeterministicGenesisState(f, 40)
+	var data []byte
+	for _, root := range newState.StateRoots() {
+		data = append(data, root...)
+	}
+	f.Add(5, int(stateTypes.BasicArray), data, uint64(params.BeaconConfig().SlotsPerHistoricalRoot))
+
+	f.Fuzz(func(t *testing.T, idx, typ int, data []byte, slotsPerHistRoot uint64) {
+		var roots [][]byte
+		for i := 32; i < len(data); i += 32 {
+			roots = append(roots, data[i-32:i])
+		}
+		trie, err := fieldtrie.NewFieldTrie(stateTypes.FieldIndex(idx), stateTypes.DataType(typ), roots, slotsPerHistRoot)
+		if err != nil {
+			return // invalid inputs
+		}
+		_, err = trie.TrieRoot()
+		if err != nil {
+			return
+		}
+	})
+}

beacon-chain/state/fieldtrie/testdata/fuzz/FuzzFieldTrie/c1898b8d556154d8a9d00cf2a64226dd5d76f33e27c373df2c409670db9b4877

@@ -0,0 +1,5 @@
+go test fuzz v1
+int(5)
+int(0)
+[]byte("")
+uint64(8234)

beacon-chain/state/interfaces.go

@@ -223,6 +223,7 @@ type FutureForkStub interface {
 	AppendInactivityScore(s uint64) error
 	CurrentEpochParticipation() ([]byte, error)
 	PreviousEpochParticipation() ([]byte, error)
+	UnrealizedCheckpointBalances() (uint64, uint64, uint64, error)
 	InactivityScores() ([]uint64, error)
 	SetInactivityScores(val []uint64) error
 	CurrentSyncCommittee() (*ethpb.SyncCommittee, error)

beacon-chain/state/state-native/BUILD.bazel

@@ -4,6 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "doc.go",
+        "error.go",
         "getters_attestation.go",
         "getters_block.go",
         "getters_checkpoint.go",
@@ -54,6 +55,7 @@ go_library(
         "//tools/pcli:__pkg__",
     ],
     deps = [
+        "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/fieldtrie:go_default_library",
         "//beacon-chain/state/state-native/custom-types:go_default_library",
@@ -83,6 +85,7 @@ go_test(
         "getters_attestation_test.go",
         "getters_block_test.go",
         "getters_checkpoint_test.go",
+        "getters_participation_test.go",
         "getters_test.go",
         "getters_validator_test.go",
         "hasher_test.go",

beacon-chain/state/state-native/error.go

@@ -0,0 +1,5 @@
+package state_native
+
+import "errors"
+
+var ErrNilParticipation = errors.New("Nil epoch participation in state")

beacon-chain/state/state-native/getters_participation.go

@@ -1,6 +1,8 @@
 package state_native
 
 import (
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/beacon-chain/state/stateutil"
 	"github.com/prysmaticlabs/prysm/runtime/version"
 )
 
@@ -36,6 +38,28 @@ func (b *BeaconState) PreviousEpochParticipation() ([]byte, error) {
 	return b.previousEpochParticipationVal(), nil
 }
 
+// UnrealizedCheckpointBalances returns the total balances: active, target attested in
+// current epoch and target attested in previous epoch. This function is used to
+// compute the "unrealized justification" that a synced Beacon Block will have.
+func (b *BeaconState) UnrealizedCheckpointBalances() (uint64, uint64, uint64, error) {
+	if b.version == version.Phase0 {
+		return 0, 0, 0, errNotSupported("UnrealizedCheckpointBalances", b.version)
+	}
+
+	b.lock.RLock()
+	defer b.lock.RUnlock()
+
+	cp := b.currentEpochParticipation
+	pp := b.previousEpochParticipation
+	if cp == nil || pp == nil {
+		return 0, 0, 0, ErrNilParticipation
+	}
+
+	currentEpoch := time.CurrentEpoch(b)
+	return stateutil.UnrealizedCheckpointBalances(cp, pp, b.validators, currentEpoch)
+
+}
+
 // currentEpochParticipationVal corresponding to participation bits on the beacon chain.
 // This assumes that a lock is already held on BeaconState.
 func (b *BeaconState) currentEpochParticipationVal() []byte {

beacon-chain/state/state-native/getters_participation_test.go

@@ -0,0 +1,64 @@
+package state_native
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/config/params"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+)
+
+func TestState_UnrealizedCheckpointBalances(t *testing.T) {
+	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
+	balances := make([]uint64, params.BeaconConfig().MinGenesisActiveValidatorCount)
+	for i := 0; i < len(validators); i++ {
+		validators[i] = &ethpb.Validator{
+			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
+			EffectiveBalance: params.BeaconConfig().MaxEffectiveBalance,
+		}
+		balances[i] = params.BeaconConfig().MaxEffectiveBalance
+	}
+	base := &ethpb.BeaconStateAltair{
+		Slot:        2,
+		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
+
+		Validators:                 validators,
+		CurrentEpochParticipation:  make([]byte, params.BeaconConfig().MinGenesisActiveValidatorCount),
+		PreviousEpochParticipation: make([]byte, params.BeaconConfig().MinGenesisActiveValidatorCount),
+		Balances:                   balances,
+	}
+	state, err := InitializeFromProtoAltair(base)
+	require.NoError(t, err)
+
+	// No one voted in the last two epochs
+	allActive := params.BeaconConfig().MinGenesisActiveValidatorCount * params.BeaconConfig().MaxEffectiveBalance
+	active, previous, current, err := state.UnrealizedCheckpointBalances()
+	require.NoError(t, err)
+	require.Equal(t, allActive, active)
+	require.Equal(t, uint64(0), current)
+	require.Equal(t, uint64(0), previous)
+
+	// Add some votes in the last two epochs:
+	base.CurrentEpochParticipation[0] = 0xFF
+	base.PreviousEpochParticipation[0] = 0xFF
+	base.PreviousEpochParticipation[1] = 0xFF
+
+	state, err = InitializeFromProtoAltair(base)
+	require.NoError(t, err)
+	active, previous, current, err = state.UnrealizedCheckpointBalances()
+	require.NoError(t, err)
+	require.Equal(t, allActive, active)
+	require.Equal(t, params.BeaconConfig().MaxEffectiveBalance, current)
+	require.Equal(t, 2*params.BeaconConfig().MaxEffectiveBalance, previous)
+
+	// Slash some validators
+	validators[0].Slashed = true
+	state, err = InitializeFromProtoAltair(base)
+	require.NoError(t, err)
+	active, previous, current, err = state.UnrealizedCheckpointBalances()
+	require.NoError(t, err)
+	require.Equal(t, allActive-params.BeaconConfig().MaxEffectiveBalance, active)
+	require.Equal(t, uint64(0), current)
+	require.Equal(t, params.BeaconConfig().MaxEffectiveBalance, previous)
+
+}

beacon-chain/state/stateutil/BUILD.bazel

@@ -15,6 +15,7 @@ go_library(
         "state_hasher.go",
         "sync_committee.root.go",
         "trie_helpers.go",
+        "unrealized_justification.go",
         "validator_map_handler.go",
         "validator_root.go",
     ],
@@ -57,6 +58,7 @@ go_test(
         "reference_bench_test.go",
         "state_root_test.go",
         "trie_helpers_test.go",
+        "unrealized_justification_test.go",
         "validator_root_test.go",
     ],
     embed = [":go_default_library"],

beacon-chain/state/stateutil/unrealized_justification.go

@@ -0,0 +1,43 @@
+package stateutil
+
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/config/params"
+	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/math"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+)
+
+func UnrealizedCheckpointBalances(cp, pp []byte, validators []*ethpb.Validator, currentEpoch types.Epoch) (uint64, uint64, uint64, error) {
+	targetIdx := params.BeaconConfig().TimelyTargetFlagIndex
+	activeBalance := uint64(0)
+	currentTarget := uint64(0)
+	prevTarget := uint64(0)
+	if len(cp) < len(validators) || len(pp) < len(validators) {
+		return 0, 0, 0, errors.New("participation does not match validator set")
+	}
+
+	var err error
+	for i, v := range validators {
+		active := v.ActivationEpoch <= currentEpoch && currentEpoch < v.ExitEpoch
+		if active && !v.Slashed {
+			activeBalance, err = math.Add64(activeBalance, v.EffectiveBalance)
+			if err != nil {
+				return 0, 0, 0, err
+			}
+			if ((cp[i] >> targetIdx) & 1) == 1 {
+				currentTarget, err = math.Add64(currentTarget, v.EffectiveBalance)
+				if err != nil {
+					return 0, 0, 0, err
+				}
+			}
+			if ((pp[i] >> targetIdx) & 1) == 1 {
+				prevTarget, err = math.Add64(prevTarget, v.EffectiveBalance)
+				if err != nil {
+					return 0, 0, 0, err
+				}
+			}
+		}
+	}
+	return activeBalance, prevTarget, currentTarget, nil
+}

beacon-chain/state/stateutil/unrealized_justification_test.go

@@ -0,0 +1,95 @@
+package stateutil
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/config/params"
+	ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/testing/require"
+)
+
+func TestState_UnrealizedCheckpointBalances(t *testing.T) {
+	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
+	targetFlag := params.BeaconConfig().TimelyTargetFlagIndex
+	expectedActive := params.BeaconConfig().MinGenesisActiveValidatorCount * params.BeaconConfig().MaxEffectiveBalance
+
+	balances := make([]uint64, params.BeaconConfig().MinGenesisActiveValidatorCount)
+	for i := 0; i < len(validators); i++ {
+		validators[i] = &ethpb.Validator{
+			ExitEpoch:        params.BeaconConfig().FarFutureEpoch,
+			EffectiveBalance: params.BeaconConfig().MaxEffectiveBalance,
+		}
+		balances[i] = params.BeaconConfig().MaxEffectiveBalance
+	}
+	cp := make([]byte, len(validators))
+	pp := make([]byte, len(validators))
+
+	t.Run("No one voted last two epochs", func(tt *testing.T) {
+		active, previous, current, err := UnrealizedCheckpointBalances(cp, pp, validators, 0)
+		require.NoError(tt, err)
+		require.Equal(tt, expectedActive, active)
+		require.Equal(tt, uint64(0), current)
+		require.Equal(tt, uint64(0), previous)
+	})
+
+	t.Run("bad votes in last two epochs", func(tt *testing.T) {
+		copy(cp, []byte{0xFF ^ (1 << targetFlag), 0xFF ^ (1 << targetFlag), 0xFF ^ (1 << targetFlag), 0x00})
+		copy(pp, []byte{0x00, 0x00, 0x00, 0x00})
+		active, previous, current, err := UnrealizedCheckpointBalances(cp, pp, validators, 1)
+		require.NoError(tt, err)
+		require.Equal(tt, expectedActive, active)
+		require.Equal(tt, uint64(0), current)
+		require.Equal(tt, uint64(0), previous)
+	})
+
+	t.Run("two votes in last epoch", func(tt *testing.T) {
+		copy(cp, []byte{0xFF ^ (1 << targetFlag), 0xFF ^ (1 << targetFlag), 0xFF ^ (1 << targetFlag), 0x00, 1 << targetFlag, 1 << targetFlag})
+		copy(pp, []byte{0x00, 0x00, 0x00, 0x00, 0xFF ^ (1 << targetFlag)})
+		active, previous, current, err := UnrealizedCheckpointBalances(cp, pp, validators, 1)
+		require.NoError(tt, err)
+		require.Equal(tt, expectedActive, active)
+		require.Equal(tt, 2*params.BeaconConfig().MaxEffectiveBalance, current)
+		require.Equal(tt, uint64(0), previous)
+	})
+
+	t.Run("two votes in previous epoch", func(tt *testing.T) {
+		copy(cp, []byte{0x00, 0x00, 0x00, 0x00, 0xFF ^ (1 << targetFlag), 0x00})
+		copy(pp, []byte{0xFF ^ (1 << targetFlag), 0xFF ^ (1 << targetFlag), 0xFF ^ (1 << targetFlag), 0x00, 1 << targetFlag, 1 << targetFlag})
+		active, previous, current, err := UnrealizedCheckpointBalances(cp, pp, validators, 1)
+		require.NoError(tt, err)
+		require.Equal(tt, expectedActive, active)
+		require.Equal(tt, uint64(0), current)
+		require.Equal(tt, 2*params.BeaconConfig().MaxEffectiveBalance, previous)
+	})
+
+	t.Run("votes in both epochs, decreased balance in first validator", func(tt *testing.T) {
+		validators[0].EffectiveBalance = params.BeaconConfig().MaxEffectiveBalance - params.BeaconConfig().MinDepositAmount
+		copy(cp, []byte{0xFF, 0xFF, 0x00, 0x00, 0xFF ^ (1 << targetFlag), 0})
+		copy(pp, []byte{0xFF ^ (1 << targetFlag), 0xFF ^ (1 << targetFlag), 0xFF ^ (1 << targetFlag), 0x00, 0xFF, 0xFF})
+		active, previous, current, err := UnrealizedCheckpointBalances(cp, pp, validators, 1)
+		require.NoError(tt, err)
+		expectedActive -= params.BeaconConfig().MinDepositAmount
+		require.Equal(tt, expectedActive, active)
+		require.Equal(tt, 2*params.BeaconConfig().MaxEffectiveBalance-params.BeaconConfig().MinDepositAmount, current)
+		require.Equal(tt, 2*params.BeaconConfig().MaxEffectiveBalance, previous)
+	})
+
+	t.Run("slash a validator", func(tt *testing.T) {
+		validators[1].Slashed = true
+		active, previous, current, err := UnrealizedCheckpointBalances(cp, pp, validators, 1)
+		require.NoError(tt, err)
+		expectedActive -= params.BeaconConfig().MaxEffectiveBalance
+		require.Equal(tt, expectedActive, active)
+		require.Equal(tt, params.BeaconConfig().MaxEffectiveBalance-params.BeaconConfig().MinDepositAmount, current)
+		require.Equal(tt, 2*params.BeaconConfig().MaxEffectiveBalance, previous)
+	})
+	t.Run("Exit a validator", func(tt *testing.T) {
+		validators[4].ExitEpoch = 1
+		active, previous, current, err := UnrealizedCheckpointBalances(cp, pp, validators, 2)
+		require.NoError(tt, err)
+		expectedActive -= params.BeaconConfig().MaxEffectiveBalance
+		require.Equal(tt, expectedActive, active)
+		require.Equal(tt, params.BeaconConfig().MaxEffectiveBalance-params.BeaconConfig().MinDepositAmount, current)
+		require.Equal(tt, params.BeaconConfig().MaxEffectiveBalance, previous)
+	})
+}