feat: implement block_to_light_client_header

CHANGELOG.md

@@ -13,6 +13,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Light client support: Implement `ComputeFieldRootsForBlockBody`.
 - Light client support: Add light client database changes.
 - Light client support: Implement capella and deneb changes.
+- Light client support: Implement `BlockToLightClientHeaderXXX` functions upto Deneb
 
 ### Changed
 

beacon-chain/rpc/eth/light-client/helpers.go

@@ -651,3 +651,221 @@ func IsBetterUpdate(newUpdate, oldUpdate *v2.LightClientUpdate) (bool, error) {
 	}
 	return newUpdate.SignatureSlot < oldUpdate.SignatureSlot, nil
 }
+
+func BlockToLightClientHeaderAltair(block interfaces.ReadOnlySignedBeaconBlock) (*structs.LightClientHeader, error) {
+	parentRootArray := block.Block().ParentRoot()
+	parentRoot := parentRootArray[:]
+
+	stateRootArray := block.Block().StateRoot()
+	stateRoot := stateRootArray[:]
+
+	bodyRootArray, err := block.Block().Body().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get body root")
+	}
+	bodyRoot := bodyRootArray[:]
+
+	return &structs.LightClientHeader{
+		Beacon: &structs.BeaconBlockHeader{
+			Slot:          hexutil.EncodeUint64(uint64(block.Block().Slot())),
+			ProposerIndex: hexutil.EncodeUint64(uint64(block.Block().ProposerIndex())),
+			ParentRoot:    hexutil.Encode(parentRoot),
+			StateRoot:     hexutil.Encode(stateRoot),
+			BodyRoot:      hexutil.Encode(bodyRoot),
+		},
+	}, nil
+}
+
+func BlockToLightClientHeaderCapella(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*structs.LightClientHeaderCapella, error) {
+	epoch := slots.ToEpoch(block.Block().Slot())
+	if epoch < params.BeaconConfig().CapellaForkEpoch {
+		return nil, fmt.Errorf("creating Capella light client header is not supported before Capella, invalid slot %d", block.Block().Slot())
+	}
+
+	payload, err := block.Block().Body().Execution()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get execution payload")
+	}
+
+	transactionsRoot, err := payload.TransactionsRoot()
+	if errors.Is(err, consensus_types.ErrUnsupportedField) {
+		transactions, err := payload.Transactions()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get transactions")
+		}
+		transactionsRootArray, err := ssz.TransactionsRoot(transactions)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get transactions root")
+		}
+		transactionsRoot = transactionsRootArray[:]
+	} else if err != nil {
+		return nil, errors.Wrap(err, "could not get transactions root")
+	}
+	withdrawalsRoot, err := payload.WithdrawalsRoot()
+	if errors.Is(err, consensus_types.ErrUnsupportedField) {
+		withdrawals, err := payload.Withdrawals()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get withdrawals")
+		}
+		withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get withdrawals root")
+		}
+		withdrawalsRoot = withdrawalsRootArray[:]
+	} else if err != nil {
+		return nil, errors.Wrap(err, "could not get withdrawals root")
+	}
+
+	executionHeader := &structs.ExecutionPayloadHeaderCapella{
+		ParentHash:       hexutil.Encode(payload.ParentHash()),
+		FeeRecipient:     hexutil.Encode(payload.FeeRecipient()),
+		StateRoot:        hexutil.Encode(payload.StateRoot()),
+		ReceiptsRoot:     hexutil.Encode(payload.ReceiptsRoot()),
+		LogsBloom:        hexutil.Encode(payload.LogsBloom()),
+		PrevRandao:       hexutil.Encode(payload.PrevRandao()),
+		BlockNumber:      hexutil.EncodeUint64(payload.BlockNumber()),
+		GasLimit:         hexutil.EncodeUint64(payload.GasLimit()),
+		GasUsed:          hexutil.EncodeUint64(payload.GasUsed()),
+		Timestamp:        hexutil.EncodeUint64(payload.Timestamp()),
+		ExtraData:        hexutil.Encode(payload.ExtraData()),
+		BaseFeePerGas:    hexutil.Encode(payload.BaseFeePerGas()),
+		BlockHash:        hexutil.Encode(payload.BlockHash()),
+		TransactionsRoot: hexutil.Encode(transactionsRoot),
+		WithdrawalsRoot:  hexutil.Encode(withdrawalsRoot),
+	}
+
+	executionPayloadProof, err := blocks.PayloadProof(ctx, block.Block())
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get execution payload proof")
+	}
+	executionPayloadProofStr := make([]string, len(executionPayloadProof))
+	for i, proof := range executionPayloadProof {
+		executionPayloadProofStr[i] = hexutil.Encode(proof)
+	}
+
+	parentRootArray := block.Block().ParentRoot()
+	parentRoot := parentRootArray[:]
+
+	stateRootArray := block.Block().StateRoot()
+	stateRoot := stateRootArray[:]
+
+	bodyRootArray, err := block.Block().Body().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get body root")
+	}
+	bodyRoot := bodyRootArray[:]
+
+	return &structs.LightClientHeaderCapella{
+		Beacon: &structs.BeaconBlockHeader{
+			Slot:          hexutil.EncodeUint64(uint64(block.Block().Slot())),
+			ProposerIndex: hexutil.EncodeUint64(uint64(block.Block().ProposerIndex())),
+			ParentRoot:    hexutil.Encode(parentRoot),
+			StateRoot:     hexutil.Encode(stateRoot),
+			BodyRoot:      hexutil.Encode(bodyRoot),
+		},
+		Execution:       executionHeader,
+		ExecutionBranch: executionPayloadProofStr,
+	}, nil
+}
+
+func BlockToLightClientHeaderDeneb(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*structs.LightClientHeaderDeneb, error) {
+	epoch := slots.ToEpoch(block.Block().Slot())
+	if epoch < params.BeaconConfig().DenebForkEpoch {
+		return nil, fmt.Errorf("creating Deneb light client header is not supported before Deneb, invalid slot %d", block.Block().Slot())
+	}
+
+	payload, err := block.Block().Body().Execution()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get execution payload")
+	}
+
+	transactionsRoot, err := payload.TransactionsRoot()
+	if errors.Is(err, consensus_types.ErrUnsupportedField) {
+		transactions, err := payload.Transactions()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get transactions")
+		}
+		transactionsRootArray, err := ssz.TransactionsRoot(transactions)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get transactions root")
+		}
+		transactionsRoot = transactionsRootArray[:]
+	} else if err != nil {
+		return nil, errors.Wrap(err, "could not get transactions root")
+	}
+	withdrawalsRoot, err := payload.WithdrawalsRoot()
+	if errors.Is(err, consensus_types.ErrUnsupportedField) {
+		withdrawals, err := payload.Withdrawals()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get withdrawals")
+		}
+		withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get withdrawals root")
+		}
+		withdrawalsRoot = withdrawalsRootArray[:]
+	} else if err != nil {
+		return nil, errors.Wrap(err, "could not get withdrawals root")
+	}
+	blobGasUsed, err := payload.BlobGasUsed()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get blob gas used")
+	}
+	excessBlobGas, err := payload.ExcessBlobGas()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get excess blob gas")
+	}
+
+	executionHeader := &structs.ExecutionPayloadHeaderDeneb{
+		ParentHash:       hexutil.Encode(payload.ParentHash()),
+		FeeRecipient:     hexutil.Encode(payload.FeeRecipient()),
+		StateRoot:        hexutil.Encode(payload.StateRoot()),
+		ReceiptsRoot:     hexutil.Encode(payload.ReceiptsRoot()),
+		LogsBloom:        hexutil.Encode(payload.LogsBloom()),
+		PrevRandao:       hexutil.Encode(payload.PrevRandao()),
+		BlockNumber:      hexutil.EncodeUint64(payload.BlockNumber()),
+		GasLimit:         hexutil.EncodeUint64(payload.GasLimit()),
+		GasUsed:          hexutil.EncodeUint64(payload.GasUsed()),
+		Timestamp:        hexutil.EncodeUint64(payload.Timestamp()),
+		ExtraData:        hexutil.Encode(payload.ExtraData()),
+		BaseFeePerGas:    hexutil.Encode(payload.BaseFeePerGas()),
+		BlockHash:        hexutil.Encode(payload.BlockHash()),
+		TransactionsRoot: hexutil.Encode(transactionsRoot),
+		WithdrawalsRoot:  hexutil.Encode(withdrawalsRoot),
+		BlobGasUsed:      hexutil.EncodeUint64(blobGasUsed),
+		ExcessBlobGas:    hexutil.EncodeUint64(excessBlobGas),
+	}
+
+	executionPayloadProof, err := blocks.PayloadProof(ctx, block.Block())
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get execution payload proof")
+	}
+	executionPayloadProofStr := make([]string, len(executionPayloadProof))
+	for i, proof := range executionPayloadProof {
+		executionPayloadProofStr[i] = hexutil.Encode(proof)
+	}
+
+	parentRootArray := block.Block().ParentRoot()
+	parentRoot := parentRootArray[:]
+
+	stateRootArray := block.Block().StateRoot()
+	stateRoot := stateRootArray[:]
+
+	bodyRootArray, err := block.Block().Body().HashTreeRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get body root")
+	}
+	bodyRoot := bodyRootArray[:]
+
+	return &structs.LightClientHeaderDeneb{
+		Beacon: &structs.BeaconBlockHeader{
+			Slot:          hexutil.EncodeUint64(uint64(block.Block().Slot())),
+			ProposerIndex: hexutil.EncodeUint64(uint64(block.Block().ProposerIndex())),
+			ParentRoot:    hexutil.Encode(parentRoot),
+			StateRoot:     hexutil.Encode(stateRoot),
+			BodyRoot:      hexutil.Encode(bodyRoot),
+		},
+		Execution:       executionHeader,
+		ExecutionBranch: executionPayloadProofStr,
+	}, nil
+}