allow users to publish blobs

Allowing users to publish blobs before publishing blocks, gives the blobs a head start. They can begin to propagate around the network while the block is being validated.

CHANGELOG.md

@@ -17,6 +17,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - GetBeaconStateV2: add Electra case.
 - Implement [consensus-specs/3875](https://github.com/ethereum/consensus-specs/pull/3875)
 - Tests to ensure sepolia config matches the official upstream yaml
+- HTTP endpoint for PublishBlobs
 
 ### Changed
 

api/server/structs/BUILD.bazel

@@ -5,6 +5,7 @@ go_library(
     srcs = [
         "block.go",
         "conversions.go",
+        "conversions_blob.go",
         "conversions_block.go",
         "conversions_lightclient.go",
         "conversions_state.go",

api/server/structs/conversions_blob.go

@@ -0,0 +1,61 @@
+package structs
+
+import (
+	"strconv"
+
+	"github.com/prysmaticlabs/prysm/v5/api/server"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+func (sc *Sidecar) ToConsensus() (*eth.BlobSidecar, error) {
+	if sc == nil {
+		return nil, errNilValue
+	}
+
+	index, err := strconv.ParseUint(sc.Index, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Index")
+	}
+
+	blob, err := bytesutil.DecodeHexWithLength(sc.Blob, 131072)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Blob")
+	}
+
+	kzgCommitment, err := bytesutil.DecodeHexWithLength(sc.KzgCommitment, 48)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "KzgCommitment")
+	}
+
+	kzgProof, err := bytesutil.DecodeHexWithLength(sc.KzgProof, 48)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "KzgProof")
+	}
+
+	header, err := sc.SignedBeaconBlockHeader.ToConsensus()
+	if err != nil {
+		return nil, server.NewDecodeError(err, "SignedBeaconBlockHeader")
+	}
+
+	// decode the commitment inclusion proof
+	var commitmentInclusionProof [][]byte
+	for _, proof := range sc.CommitmentInclusionProof {
+		proofBytes, err := bytesutil.DecodeHexWithLength(proof, 32)
+		if err != nil {
+			return nil, server.NewDecodeError(err, "CommitmentInclusionProof")
+		}
+		commitmentInclusionProof = append(commitmentInclusionProof, proofBytes)
+	}
+
+	bsc := &eth.BlobSidecar{
+		Index:                    index,
+		Blob:                     blob,
+		KzgCommitment:            kzgCommitment,
+		KzgProof:                 kzgProof,
+		SignedBlockHeader:        header,
+		CommitmentInclusionProof: commitmentInclusionProof,
+	}
+
+	return bsc, nil
+}

api/server/structs/conversions_block.go

@@ -20,6 +20,9 @@ import (
 var ErrUnsupportedConversion = errors.New("Could not determine api struct type to use for value")
 
 func (h *SignedBeaconBlockHeader) ToConsensus() (*eth.SignedBeaconBlockHeader, error) {
+	if h == nil {
+		return nil, errNilValue
+	}
 	msg, err := h.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
@@ -36,6 +39,9 @@ func (h *SignedBeaconBlockHeader) ToConsensus() (*eth.SignedBeaconBlockHeader, e
 }
 
 func (h *BeaconBlockHeader) ToConsensus() (*eth.BeaconBlockHeader, error) {
+	if h == nil {
+		return nil, errNilValue
+	}
 	s, err := strconv.ParseUint(h.Slot, 10, 64)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Slot")

api/server/structs/endpoints_blob.go

@@ -12,3 +12,12 @@ type Sidecar struct {
 	KzgProof                 string                   `json:"kzg_proof"`
 	CommitmentInclusionProof []string                 `json:"kzg_commitment_inclusion_proof"`
 }
+
+type BlobSidecars struct {
+	Sidecars []*Sidecar `json:"sidecars"`
+}
+
+type PublishBlobsRequest struct {
+	BlobSidecars *BlobSidecars `json:"blob_sidecars"`
+	BlockRoot    string        `json:"block_root"`
+}

beacon-chain/rpc/endpoints.go

@@ -942,6 +942,8 @@ func (s *Service) prysmBeaconEndpoints(
 		ChainInfoFetcher:      s.cfg.ChainInfoFetcher,
 		FinalizationFetcher:   s.cfg.FinalizationFetcher,
 		CoreService:           coreService,
+		Broadcaster:           s.cfg.Broadcaster,
+		BlobReceiver:          s.cfg.BlobReceiver,
 	}
 
 	const namespace = "prysm.beacon"
@@ -992,6 +994,16 @@ func (s *Service) prysmBeaconEndpoints(
 			handler: server.GetChainHead,
 			methods: []string{http.MethodGet},
 		},
+		{
+			template: "/prysm/v1/beacon/blobs",
+			name:     namespace + ".PublishBlobs",
+			middleware: []middleware.Middleware{
+				middleware.ContentTypeHandler([]string{api.JsonMediaType}),
+				middleware.AcceptHeaderHandler([]string{api.JsonMediaType}),
+			},
+			handler: server.PublishBlobs,
+			methods: []string{http.MethodPost},
+		},
 	}
 }
 

beacon-chain/rpc/endpoints_test.go

@@ -115,6 +115,7 @@ func Test_endpoints(t *testing.T) {
 		"/eth/v1/beacon/states/{state_id}/validator_count":   {http.MethodGet},
 		"/prysm/v1/beacon/states/{state_id}/validator_count": {http.MethodGet},
 		"/prysm/v1/beacon/chain_head":                        {http.MethodGet},
+		"/prysm/v1/beacon/blobs":                             {http.MethodPost},
 	}
 
 	prysmNodeRoutes := map[string][]string{

beacon-chain/rpc/prysm/beacon/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/db:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
         "//beacon-chain/rpc/core:go_default_library",
         "//beacon-chain/rpc/eth/helpers:go_default_library",
         "//beacon-chain/rpc/eth/shared:go_default_library",
@@ -22,9 +23,11 @@ go_library(
         "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/sync:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
+        "//encoding/bytesutil:go_default_library",
         "//network/httputil:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
@@ -47,13 +50,16 @@ go_test(
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
         "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//beacon-chain/rpc/core:go_default_library",
         "//beacon-chain/rpc/lookup:go_default_library",
+        "//beacon-chain/rpc/prysm/testing:go_default_library",
         "//beacon-chain/rpc/testutil:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/state/stategen/mock:go_default_library",
+        "//beacon-chain/sync/initial-sync/testing:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",

beacon-chain/rpc/prysm/beacon/handlers.go

@@ -15,7 +15,9 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/core"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/rpc/eth/shared"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	"github.com/prysmaticlabs/prysm/v5/network/httputil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -183,3 +185,52 @@ func (s *Server) GetChainHead(w http.ResponseWriter, r *http.Request) {
 	}
 	httputil.WriteJson(w, response)
 }
+
+func (s *Server) PublishBlobs(w http.ResponseWriter, r *http.Request) {
+	ctx, span := trace.StartSpan(r.Context(), "beacon.PublishBlobs")
+	defer span.End()
+	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
+		return
+	}
+
+	var req structs.PublishBlobsRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		httputil.HandleError(w, "Could not decode JSON request body", http.StatusBadRequest)
+		return
+	}
+	if req.BlobSidecars == nil {
+		httputil.HandleError(w, "Missing blob sidecars", http.StatusBadRequest)
+		return
+	}
+
+	root, err := bytesutil.DecodeHexWithLength(req.BlockRoot, 32)
+	if err != nil {
+		httputil.HandleError(w, "Could not decode block root", http.StatusBadRequest)
+		return
+	}
+
+	for _, blobSidecar := range req.BlobSidecars.Sidecars {
+		sc, err := blobSidecar.ToConsensus()
+		if err != nil {
+			httputil.HandleError(w, "Could not decode blob sidecar", http.StatusBadRequest)
+			return
+		}
+
+		readOnlySc, err := blocks.NewROBlobWithRoot(sc, bytesutil.ToBytes32(root))
+		if err != nil {
+			httputil.HandleError(w, "Could not create read-only blob", http.StatusInternalServerError)
+			return
+		}
+
+		verifiedBlob := blocks.NewVerifiedROBlob(readOnlySc)
+		if err := s.BlobReceiver.ReceiveBlob(ctx, verifiedBlob); err != nil {
+			httputil.HandleError(w, "Could not receive blob", http.StatusInternalServerError)
+			return
+		}
+
+		if err := s.Broadcaster.BroadcastBlob(ctx, sc.Index, sc); err != nil {
+			httputil.HandleError(w, "Failed to broadcast blob", http.StatusInternalServerError)
+			return
+		}
+	}
+}