feat: add system config consensus to deprecate clique (#1102)

* feat: add system config consensus to deprecate poa

* fix: check extra field lens

* Finish implementation with one signer only

* Implement unit tests

* Only check signature if block not requested

* Remove Extra from rlp encoding (and hashing)

* Implement UpgradableEngine as middleware for Clique/SystemContract

* Use isEuclid, add json tag to Requested, make go idiomatic

* Changes post integration test

* Remove comment

* Address comments

* Merge

* New field BlockSignature (not used in hashing/JSON)

* Enforce .Extra to be an empty slice

* replace header.Requested for header.IsNewBlock

* mark new block as IsNewBlock

* Make new RLP optional fields always default for legacy/reth compatibility

* Placing new fields as last non-zero rlp:optional values used by Scroll

* Penalize nodes that send non-zero Euclid V2 header field values

* Bring back .Requested to downloader instead of .IsNewBlock

* Replace IsNewBlock for Requested

* Address comments

* merge

* prevent timing issues in tests

* fix ci

* chore: auto version bump [bot]

* Update consensus/system_contract/consensus.go

Co-authored-by: Morty <70688412+yiweichi@users.noreply.github.com>

* chore: auto version bump [bot]

* Update consensus/system_contract/consensus.go

Co-authored-by: Jonas Theis <4181434+jonastheis@users.noreply.github.com>

* Remove whitespaces and merge version number

* chore: auto version bump [bot]

* validate that the read address from L1 is not empty and improved error handling when fetching address

* Fix indentation issue

* Fix test

* goimports fix

* goimports

---------

Co-authored-by: Alejandro Ranchal-Pedrosa <a.ranchalpedrosa@gmail.com>
Co-authored-by: jonastheis <4181434+jonastheis@users.noreply.github.com>
Co-authored-by: jonastheis <jonastheis@users.noreply.github.com>
Co-authored-by: ranchalp <ranchalp@users.noreply.github.com>
Co-authored-by: Péter Garamvölgyi <peter@scroll.io>

cmd/faucet/faucet.go

@@ -254,7 +254,7 @@ func newFaucet(genesis *core.Genesis, port int, enodes []*enode.Node, network ui
 	cfg.Genesis = genesis
 	utils.SetDNSDiscoveryDefaults(&cfg, genesis.ToBlock(nil).Hash())
 
-	lesBackend, err := les.New(stack, &cfg)
+	lesBackend, err := les.New(stack, &cfg, nil)
 	if err != nil {
 		return nil, fmt.Errorf("Failed to register the Ethereum service: %w", err)
 	}

cmd/utils/flags.go

@@ -2048,16 +2048,6 @@ func SetDNSDiscoveryDefaults(cfg *ethconfig.Config, genesis common.Hash) {
 // The second return value is the full node instance, which may be nil if the
 // node is running as a light client.
 func RegisterEthService(stack *node.Node, cfg *ethconfig.Config) (ethapi.Backend, *eth.Ethereum) {
-	if cfg.SyncMode == downloader.LightSync {
-		backend, err := les.New(stack, cfg)
-		if err != nil {
-			Fatalf("Failed to register the Ethereum service: %v", err)
-		}
-		scrollTracerWrapper := tracing.NewTracerWrapper()
-		stack.RegisterAPIs(tracers.APIs(backend.ApiBackend, scrollTracerWrapper))
-		return backend.ApiBackend, nil
-	}
-
 	// initialize L1 client for sync service
 	// note: we need to do this here to avoid circular dependency
 	l1EndpointUrl := stack.Config().L1Endpoint
@@ -2073,6 +2063,16 @@ func RegisterEthService(stack *node.Node, cfg *ethconfig.Config) (ethapi.Backend
 		log.Info("Initialized L1 client", "endpoint", l1EndpointUrl)
 	}
 
+	if cfg.SyncMode == downloader.LightSync {
+		backend, err := les.New(stack, cfg, l1Client)
+		if err != nil {
+			Fatalf("Failed to register the Ethereum service: %v", err)
+		}
+		scrollTracerWrapper := tracing.NewTracerWrapper()
+		stack.RegisterAPIs(tracers.APIs(backend.ApiBackend, scrollTracerWrapper))
+		return backend.ApiBackend, nil
+	}
+
 	backend, err := eth.New(stack, cfg, l1Client)
 	if err != nil {
 		Fatalf("Failed to register the Ethereum service: %v", err)

consensus/system_contract/api.go

@@ -0,0 +1,18 @@
+package system_contract
+
+import (
+	"github.com/scroll-tech/go-ethereum/common"
+	"github.com/scroll-tech/go-ethereum/consensus"
+	"github.com/scroll-tech/go-ethereum/rpc"
+)
+
+// API is a user facing RPC API to allow controlling the signer and voting
+// mechanisms of the proof-of-authority scheme.
+type API struct {
+	chain consensus.ChainHeaderReader
+}
+
+// GetSigners retrieves the list of authorized signers at the specified block.
+func (api *API) GetSigners(number *rpc.BlockNumber) ([]common.Address, error) {
+	return nil, nil
+}

consensus/system_contract/consensus.go

@@ -0,0 +1,388 @@
+package system_contract
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+	"time"
+
+	"golang.org/x/crypto/sha3"
+
+	"github.com/scroll-tech/go-ethereum/accounts"
+	"github.com/scroll-tech/go-ethereum/common"
+	"github.com/scroll-tech/go-ethereum/consensus"
+	"github.com/scroll-tech/go-ethereum/consensus/misc"
+	"github.com/scroll-tech/go-ethereum/core/state"
+	"github.com/scroll-tech/go-ethereum/core/types"
+	"github.com/scroll-tech/go-ethereum/crypto"
+	"github.com/scroll-tech/go-ethereum/log"
+	"github.com/scroll-tech/go-ethereum/rlp"
+	"github.com/scroll-tech/go-ethereum/rpc"
+	"github.com/scroll-tech/go-ethereum/trie"
+)
+
+var (
+	extraSeal = crypto.SignatureLength   // Fixed number of extra-data suffix bytes reserved for signer seal
+	uncleHash = types.CalcUncleHash(nil) // Always Keccak256(RLP([])) as uncles are meaningless outside of PoW.
+)
+
+// Various error messages to mark blocks invalid. These should be private to
+// prevent engine specific errors from being referenced in the remainder of the
+// codebase, inherently breaking if the engine is swapped out. Please put common
+// error types into the consensus package.
+var (
+	// errUnknownBlock is returned when the list of signers is requested for a block
+	// that is not part of the local blockchain.
+	errUnknownBlock = errors.New("unknown block")
+	// errNonceNotEmpty is returned if a nonce value is non-zero
+	errInvalidNonce = errors.New("nonce not empty nor zero")
+	// errMissingSignature is returned if a block's extra-data section doesn't seem
+	// to contain a 65 byte secp256k1 signature.
+	errMissingSignature = errors.New("extra-data 65 byte signature missing")
+	// errInvalidMixDigest is returned if a block's mix digest is non-zero.
+	errInvalidMixDigest = errors.New("non-zero mix digest")
+	// errInvalidUncleHash is returned if a block contains an non-empty uncle list.
+	errInvalidUncleHash = errors.New("non empty uncle hash")
+	// errInvalidDifficulty is returned if a difficulty value is non-zero
+	errInvalidDifficulty = errors.New("non-one difficulty")
+	// errInvalidTimestamp is returned if the timestamp of a block is lower than
+	// the previous block's timestamp + the minimum block period.
+	errInvalidTimestamp = errors.New("invalid timestamp")
+	// errInvalidExtra is returned if the extra data is not empty
+	errInvalidExtra = errors.New("invalid extra")
+)
+
+// ErrUnauthorizedSigner is returned if a header is signed by a non-authorized entity.
+var ErrUnauthorizedSigner = errors.New("unauthorized signer")
+
+// SignerFn hashes and signs the data to be signed by a backing account.
+type SignerFn func(signer accounts.Account, mimeType string, message []byte) ([]byte, error)
+
+// Author implements consensus.Engine, returning the Ethereum address recovered
+// from the signature in the header's block-signature section.
+func (s *SystemContract) Author(header *types.Header) (common.Address, error) {
+	return ecrecover(header)
+}
+
+// VerifyHeader checks whether a header conforms to the consensus rules of a
+// given engine.
+func (s *SystemContract) VerifyHeader(chain consensus.ChainHeaderReader, header *types.Header, seal bool) error {
+	return s.verifyHeader(chain, header, nil)
+}
+
+// VerifyHeaders is similar to VerifyHeader, but verifies a batch of headers
+// concurrently. The method returns a quit channel to abort the operations and
+// a results channel to retrieve the async verifications (the order is that of
+// the input slice).
+func (s *SystemContract) VerifyHeaders(chain consensus.ChainHeaderReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) {
+	abort := make(chan struct{})
+	results := make(chan error, len(headers))
+
+	go func() {
+		for i, header := range headers {
+			err := s.verifyHeader(chain, header, headers[:i])
+			if err != nil {
+				log.Error("Error verifying headers", "err", err)
+			}
+			select {
+			case <-abort:
+				return
+			case results <- err:
+			}
+		}
+	}()
+	return abort, results
+}
+
+// verifyHeader checks whether a header conforms to the consensus rules.The
+// caller may optionally pass in a batch of parents (ascending order) to avoid
+// looking those up from the database. This is useful for concurrently verifying
+// a batch of new headers.
+func (s *SystemContract) verifyHeader(chain consensus.ChainHeaderReader, header *types.Header, parents []*types.Header) error {
+	if header.Number == nil {
+		return errUnknownBlock
+	}
+
+	// Don't waste time checking blocks from the future
+	if header.Time > uint64(time.Now().Unix()) {
+		return consensus.ErrFutureBlock
+	}
+	// Ensure that the nonce is zero
+	if header.Nonce != (types.BlockNonce{}) {
+		return errInvalidNonce
+	}
+	// Check that the BlockSignature contains signature if block is not requested
+	if !header.Requested && header.Number.Cmp(big.NewInt(0)) != 0 && len(header.BlockSignature) != extraSeal {
+		return errMissingSignature
+	}
+	// Ensure that the mix digest is zero
+	if header.MixDigest != (common.Hash{}) {
+		return errInvalidMixDigest
+	}
+	// Ensure that the block doesn't contain any uncles which are meaningless in PoA
+	if header.UncleHash != uncleHash {
+		return errInvalidUncleHash
+	}
+	// Ensure that the difficulty is one
+	if header.Difficulty.Cmp(common.Big1) != 0 {
+		return errInvalidDifficulty
+	}
+	// Verify that the gas limit is <= 2^63-1
+	cap := uint64(0x7fffffffffffffff)
+	if header.GasLimit > cap {
+		return fmt.Errorf("invalid gasLimit: have %v, max %v", header.GasLimit, cap)
+	}
+	if len(header.Extra) > 0 {
+		return errInvalidExtra
+	}
+	//// All basic checks passed, verify cascading fields
+	return s.verifyCascadingFields(chain, header, parents)
+}
+
+// verifyCascadingFields verifies all the header fields that are not standalone,
+// rather depend on a batch of previous headers. The caller may optionally pass
+// in a batch of parents (ascending order) to avoid looking those up from the
+// database. This is useful for concurrently verifying a batch of new headers.
+func (s *SystemContract) verifyCascadingFields(chain consensus.ChainHeaderReader, header *types.Header, parents []*types.Header) error {
+	// The genesis block is the always valid dead-end
+	number := header.Number.Uint64()
+	if number == 0 {
+		return nil
+	}
+	// Ensure that the block's timestamp isn't too close to its parent
+	var parent *types.Header
+	if len(parents) > 0 {
+		parent = parents[len(parents)-1]
+	} else {
+		parent = chain.GetHeader(header.ParentHash, number-1)
+	}
+	if parent == nil || parent.Number.Uint64() != number-1 || parent.Hash() != header.ParentHash {
+		return consensus.ErrUnknownAncestor
+	}
+	if header.Time < parent.Time {
+		return errInvalidTimestamp
+	}
+	// Verify that the gasUsed is <= gasLimit
+	if header.GasUsed > header.GasLimit {
+		return fmt.Errorf("invalid gasUsed: have %d, gasLimit %d", header.GasUsed, header.GasLimit)
+	}
+	if !chain.Config().IsCurie(header.Number) {
+		// Verify BaseFee not present before EIP-1559 fork.
+		if header.BaseFee != nil {
+			return fmt.Errorf("invalid baseFee before fork: have %d, want <nil>", header.BaseFee)
+		}
+		if err := misc.VerifyGaslimit(parent.GasLimit, header.GasLimit); err != nil {
+			return err
+		}
+	} else if err := misc.VerifyEip1559Header(chain.Config(), parent, header); err != nil {
+		// Verify the header's EIP-1559 attributes.
+		return err
+	}
+
+	// only if block header has NOT been requested, then verify the signature against the current signer
+	if !header.Requested {
+		signer, err := ecrecover(header)
+		if err != nil {
+			return err
+		}
+
+		s.lock.RLock()
+		defer s.lock.RUnlock()
+
+		if signer != s.signerAddressL1 {
+			log.Error("Unauthorized signer", "Got", signer, "Expected:", s.signerAddressL1)
+			return ErrUnauthorizedSigner
+		}
+	}
+
+	return nil
+}
+
+// VerifyUncles implements consensus.Engine, always returning an error for any
+// uncles as this consensus mechanism doesn't permit uncles.
+func (s *SystemContract) VerifyUncles(chain consensus.ChainReader, block *types.Block) error {
+	if len(block.Uncles()) > 0 {
+		return errors.New("uncles not allowed")
+	}
+	return nil
+}
+
+// Prepare initializes the consensus fields of a block header according to the
+// rules of a particular engine. Update only timestamp and prepare ExtraData for Signature
+func (s *SystemContract) Prepare(chain consensus.ChainHeaderReader, header *types.Header) error {
+	header.BlockSignature = make([]byte, extraSeal)
+	header.IsEuclidV2 = true
+	header.Extra = nil
+	// Ensure the timestamp has the correct delay
+	parent := chain.GetHeader(header.ParentHash, header.Number.Uint64()-1)
+	if parent == nil {
+		return consensus.ErrUnknownAncestor
+	}
+	header.Time = parent.Time + s.config.Period
+	// If RelaxedPeriod is enabled, always set the header timestamp to now (ie the time we start building it) as
+	// we don't know when it will be sealed
+	if s.config.RelaxedPeriod || header.Time < uint64(time.Now().Unix()) {
+		header.Time = uint64(time.Now().Unix())
+	}
+	header.Difficulty = big.NewInt(1)
+	return nil
+}
+
+// Finalize implements consensus.Engine. There is no post-transaction
+// No rules here
+func (s *SystemContract) Finalize(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header) {
+	// No block rewards in PoA, so the state remains as is
+}
+
+// FinalizeAndAssemble implements consensus.Engine, ensuring no uncles are set,
+// nor block rewards given, and returns the final block.
+func (s *SystemContract) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {
+	// Finalize block
+	s.Finalize(chain, header, state, txs, uncles)
+
+	// Assign the final state root to header.
+	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
+
+	// Assemble and return the final block for sealing.
+	return types.NewBlock(header, txs, nil, receipts, trie.NewStackTrie(nil)), nil
+}
+
+// Seal implements consensus.Engine, attempting to create a sealed block using
+// the local signing credentials.
+func (s *SystemContract) Seal(chain consensus.ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error {
+	header := block.Header()
+	// Sealing the genesis block is not supported
+	number := header.Number.Uint64()
+	if number == 0 {
+		return errUnknownBlock
+	}
+
+	// For 0-period chains, refuse to seal empty blocks (no reward but would spin sealing)
+	if s.config.Period == 0 && len(block.Transactions()) == 0 {
+		return errors.New("sealing paused while waiting for transactions")
+	}
+
+	// Don't hold the signer fields for the entire sealing procedure
+	s.lock.RLock()
+	signer, signFn := s.signer, s.signFn
+	signerAddressL1 := s.signerAddressL1
+	s.lock.RUnlock()
+
+	// Bail out if we are unauthorized to sign a block
+	if signer != signerAddressL1 {
+		return ErrUnauthorizedSigner
+	}
+
+	// Sweet, the protocol permits us to sign the block, wait for our time
+	delay := time.Unix(int64(header.Time), 0).Sub(time.Now()) // nolint: gosimple
+
+	// Sign all the things!
+	sighash, err := signFn(accounts.Account{Address: signer}, accounts.MimetypeClique, SystemContractRLP(header))
+	if err != nil {
+		return err
+	}
+	copy(header.BlockSignature[0:], sighash)
+	// Wait until sealing is terminated or delay timeout.
+	log.Trace("Waiting for slot to sign and propagate", "delay", common.PrettyDuration(delay))
+	go func() {
+		defer close(results)
+
+		select {
+		case <-stop:
+			return
+		case <-time.After(delay):
+		}
+
+		select {
+		case results <- block.WithSeal(header):
+		case <-time.After(time.Second):
+			log.Warn("Sealing result is not read by miner", "sealhash", SealHash(header))
+		}
+	}()
+
+	return nil
+}
+
+// SealHash returns the hash of a block prior to it being sealed.
+func (s *SystemContract) SealHash(header *types.Header) (hash common.Hash) {
+	return SealHash(header)
+}
+
+// SealHash returns the hash of a block prior to it being sealed.
+func SealHash(header *types.Header) (hash common.Hash) {
+	hasher := sha3.NewLegacyKeccak256()
+	encodeSigHeader(hasher, header)
+	hasher.(crypto.KeccakState).Read(hash[:])
+	return hash
+}
+
+// ecrecover extracts the Ethereum account address from a signed header.
+func ecrecover(header *types.Header) (common.Address, error) {
+	signature := header.BlockSignature[0:]
+
+	// Recover the public key and the Ethereum address
+	pubkey, err := crypto.Ecrecover(SealHash(header).Bytes(), signature)
+	if err != nil {
+		return common.Address{}, err
+	}
+	var signer common.Address
+	copy(signer[:], crypto.Keccak256(pubkey[1:])[12:])
+
+	return signer, nil
+}
+
+// SystemContractRLP returns the rlp bytes which needs to be signed for the system contract
+// sealing. The RLP to sign consists of the entire header apart from the ExtraData
+//
+// Note, the method requires the extra data to be at least 65 bytes, otherwise it
+// panics. This is done to avoid accidentally using both forms (signature present
+// or not), which could be abused to produce different hashes for the same header.
+func SystemContractRLP(header *types.Header) []byte {
+	b := new(bytes.Buffer)
+	encodeSigHeader(b, header)
+	return b.Bytes()
+}
+
+// CalcDifficulty implements consensus.Engine. There is no difficulty rules here
+func (s *SystemContract) CalcDifficulty(chain consensus.ChainHeaderReader, time uint64, parent *types.Header) *big.Int {
+	return nil
+}
+
+// APIs implements consensus.Engine, returning the user facing RPC API to allow
+// controlling the signer voting.
+func (s *SystemContract) APIs(chain consensus.ChainHeaderReader) []rpc.API {
+	return []rpc.API{{
+		Namespace: "system_contract",
+		Service:   &API{},
+	}}
+}
+
+func encodeSigHeader(w io.Writer, header *types.Header) {
+	enc := []interface{}{
+		header.ParentHash,
+		header.UncleHash,
+		header.Coinbase,
+		header.Root,
+		header.TxHash,
+		header.ReceiptHash,
+		header.Bloom,
+		header.Difficulty,
+		header.Number,
+		header.GasLimit,
+		header.GasUsed,
+		header.Time,
+		header.MixDigest,
+		header.Nonce,
+	}
+	if header.BaseFee != nil {
+		enc = append(enc, header.BaseFee)
+	}
+	if header.WithdrawalsHash != nil {
+		panic("unexpected withdrawal hash value")
+	}
+	if err := rlp.Encode(w, enc); err != nil {
+		panic("can't encode: " + err.Error())
+	}
+}

consensus/system_contract/system_contract.go

@@ -0,0 +1,125 @@
+package system_contract
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/scroll-tech/go-ethereum/common"
+	"github.com/scroll-tech/go-ethereum/log"
+	"github.com/scroll-tech/go-ethereum/params"
+	"github.com/scroll-tech/go-ethereum/rollup/sync_service"
+)
+
+const (
+	defaultSyncInterval = 10 * time.Second
+)
+
+// SystemContract
+type SystemContract struct {
+	config *params.SystemContractConfig // Consensus engine configuration parameters
+	client sync_service.EthClient
+
+	signerAddressL1 common.Address // Address of the signer stored in L1 System Contract
+
+	signer common.Address // Ethereum address of the signing key
+	signFn SignerFn       // Signer function to authorize hashes with
+	lock   sync.RWMutex   // Protects the signer and proposals fields
+
+	ctx    context.Context
+	cancel context.CancelFunc
+}
+
+// New creates a SystemContract consensus engine with the initial
+// signers set to the ones provided by the user.
+func New(ctx context.Context, config *params.SystemContractConfig, client sync_service.EthClient) *SystemContract {
+	ctx, cancel := context.WithCancel(ctx)
+
+	s := &SystemContract{
+		config: config,
+		client: client,
+
+		ctx:    ctx,
+		cancel: cancel,
+	}
+
+	if err := s.fetchAddressFromL1(); err != nil {
+		log.Error("failed to fetch signer address from L1", "err", err)
+	}
+	return s
+}
+
+// Authorize injects a private key into the consensus engine to mint new blocks
+// with.
+func (s *SystemContract) Authorize(signer common.Address, signFn SignerFn) {
+	log.Info("Authorizing system contract", "signer", signer.Hex())
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	s.signer = signer
+	s.signFn = signFn
+}
+
+func (s *SystemContract) Start() {
+	go func() {
+		log.Info("starting SystemContract")
+		syncTicker := time.NewTicker(defaultSyncInterval)
+		defer syncTicker.Stop()
+		for {
+			select {
+			case <-s.ctx.Done():
+				return
+			default:
+			}
+			select {
+			case <-s.ctx.Done():
+				return
+			case <-syncTicker.C:
+				if err := s.fetchAddressFromL1(); err != nil {
+					log.Error("failed to fetch signer address from L1", "err", err)
+				}
+			}
+		}
+	}()
+}
+
+func (s *SystemContract) fetchAddressFromL1() error {
+	address, err := s.client.StorageAt(s.ctx, s.config.SystemContractAddress, s.config.SystemContractSlot, nil)
+	if err != nil {
+		return fmt.Errorf("failed to get signer address from L1 System Contract: %w", err)
+	}
+	bAddress := common.BytesToAddress(address)
+
+	// Validate the address is not empty
+	if bAddress == (common.Address{}) {
+		return fmt.Errorf("retrieved empty signer address from L1 System Contract")
+	}
+
+	log.Debug("Read address from system contract", "address", bAddress.Hex())
+
+	s.lock.RLock()
+	addressChanged := s.signerAddressL1 != bAddress
+	s.lock.RUnlock()
+
+	if addressChanged {
+		s.lock.Lock()
+		s.signerAddressL1 = bAddress
+		s.lock.Unlock()
+	}
+
+	return nil
+}
+
+// Close implements consensus.Engine.
+func (s *SystemContract) Close() error {
+	s.cancel()
+	return nil
+}
+
+func (s *SystemContract) currentSignerAddressL1() common.Address {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+
+	return s.signerAddressL1
+}

consensus/system_contract/system_contract_test.go

@@ -0,0 +1,223 @@
+package system_contract
+
+import (
+	"context"
+	"math/big"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/scroll-tech/go-ethereum"
+	"github.com/scroll-tech/go-ethereum/accounts"
+	"github.com/scroll-tech/go-ethereum/common"
+	"github.com/scroll-tech/go-ethereum/core/types"
+	"github.com/scroll-tech/go-ethereum/log"
+	"github.com/scroll-tech/go-ethereum/params"
+	"github.com/scroll-tech/go-ethereum/rollup/sync_service"
+	"github.com/scroll-tech/go-ethereum/trie"
+)
+
+var _ sync_service.EthClient = &fakeEthClient{}
+
+func TestSystemContract_FetchSigner(t *testing.T) {
+	log.Root().SetHandler(log.DiscardHandler())
+
+	expectedSigner := common.HexToAddress("0x1234567890abcdef1234567890abcdef12345678")
+
+	fakeClient := &fakeEthClient{value: expectedSigner}
+
+	config := &params.SystemContractConfig{
+		SystemContractAddress: common.HexToAddress("0xFAKE"),
+		// The slot number can be arbitrary – fake client doesn't use it.
+		Period:        10,
+		RelaxedPeriod: false,
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	sys := New(ctx, config, fakeClient)
+	defer sys.Close()
+
+	require.NoError(t, sys.fetchAddressFromL1())
+
+	actualSigner := sys.currentSignerAddressL1()
+
+	// Verify that the fetched signer equals the expectedSigner from our fake client.
+	require.Equal(t, expectedSigner, actualSigner, "The SystemContract should update signerAddressL1 to the value provided by the client")
+}
+
+func TestSystemContract_AuthorizeCheck(t *testing.T) {
+	// This test verifies that if the local signer does not match the authorized signer,
+	// then the Seal() function returns an error.
+
+	expectedSigner := common.HexToAddress("0x1234567890abcdef1234567890abcdef12345678")
+
+	fakeClient := &fakeEthClient{value: expectedSigner}
+	config := &params.SystemContractConfig{
+		SystemContractAddress: common.HexToAddress("0xFAKE"),
+		Period:                10,
+		RelaxedPeriod:         false,
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	sys := New(ctx, config, fakeClient)
+	defer sys.Close()
+
+	require.NoError(t, sys.fetchAddressFromL1())
+
+	// Authorize with a different signer than expected.
+	differentSigner := common.HexToAddress("0xABCDEFabcdefABCDEFabcdefabcdefABCDEFABCD")
+	sys.Authorize(differentSigner, func(acc accounts.Account, mimeType string, message []byte) ([]byte, error) {
+		// For testing, return a dummy signature
+		return []byte("dummy_sig"), nil
+	})
+
+	// Create a dummy block header.
+	// We only need the block number and blocksignature data length for this test.
+	header := &types.Header{
+		Number: big.NewInt(100),
+		// We use an extra slice with length equal to extraSeal
+		BlockSignature: make([]byte, extraSeal),
+	}
+
+	// Call Seal() and expect an error since local signer != authorized signer.
+	results := make(chan *types.Block)
+	stop := make(chan struct{})
+	err := sys.Seal(nil, (&types.Block{}).WithSeal(header), results, stop)
+
+	require.Error(t, err, "Seal should return an error when the local signer is not authorized")
+}
+
+// TestSystemContract_SignsAfterUpdate simulates:
+//  1. Initially, the SystemContract authorized signer (from StorageAt) is not the signer of the Block.
+//  2. Later, after updating the fake client to the correct signer, the background
+//     poll updates the SystemContract.
+//  3. Once updated, if the local signing key is set to match, Seal() should succeed.
+func TestSystemContract_SignsAfterUpdate(t *testing.T) {
+	// Silence logging during tests.
+	log.Root().SetHandler(log.DiscardHandler())
+
+	// Define two addresses: one "wrong" and one "correct".
+	oldSigner := common.HexToAddress("0x1111111111111111111111111111111111111111")
+	updatedSigner := common.HexToAddress("0x2222222222222222222222222222222222222222")
+
+	// Create a fake client that starts by returning the wrong signer.
+	fakeClient := &fakeEthClient{
+		value: oldSigner,
+	}
+
+	config := &params.SystemContractConfig{
+		SystemContractAddress: common.HexToAddress("0xFAKE"), // Dummy value
+		Period:                10,                            // arbitrary non-zero value
+		RelaxedPeriod:         false,
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+
+	sys := New(ctx, config, fakeClient)
+	defer sys.Close()
+
+	require.NoError(t, sys.fetchAddressFromL1())
+
+	// Verify that initially the fetched signer equals oldSigner.
+	initialSigner := sys.currentSignerAddressL1()
+	require.Equal(t, oldSigner, initialSigner, "Initial signerAddressL1 should be oldSigner")
+
+	// Now, simulate an update: change the fake client's returned value to updatedSigner.
+	fakeClient.mu.Lock()
+	fakeClient.value = updatedSigner
+	fakeClient.mu.Unlock()
+
+	// fetch new value from L1 (simulating a background poll)
+	require.NoError(t, sys.fetchAddressFromL1())
+
+	// Verify that system contract's signerAddressL1 is now updated to updatedSigner.
+	newSigner := sys.currentSignerAddressL1()
+	require.Equal(t, newSigner, updatedSigner, "SignerAddressL1 should update to updatedSigner after polling")
+
+	// Now simulate authorizing with the correct local signer.
+	sys.Authorize(updatedSigner, func(acc accounts.Account, mimeType string, message []byte) ([]byte, error) {
+		// For testing, return a dummy signature.
+		return []byte("dummy_signature"), nil
+	})
+
+	// Create a dummy header for sealing.
+	header := &types.Header{
+		Number:         big.NewInt(100),
+		BlockSignature: make([]byte, extraSeal),
+	}
+
+	// Construct a new block from the header using NewBlock constructor.
+	block := types.NewBlock(header, nil, nil, nil, trie.NewStackTrie(nil))
+
+	results := make(chan *types.Block)
+	stop := make(chan struct{})
+
+	// Call Seal. It should succeed (i.e. return no error) because local signer now equals authorized signer.
+	err := sys.Seal(nil, block, results, stop)
+	require.NoError(t, err, "Seal should succeed when the local signer is authorized after update")
+
+	// Wait for the result from Seal's goroutine.
+	select {
+	case sealedBlock := <-results:
+		require.NotNil(t, sealedBlock, "Seal should eventually return a sealed block")
+		// Optionally, you may log or further inspect sealedBlock here.
+	case <-time.After(15 * time.Second):
+		t.Fatal("Timed out waiting for Seal to return a sealed block")
+	}
+}
+
+// fakeEthClient implements a minimal version of sync_service.EthClient for testing purposes.
+type fakeEthClient struct {
+	mu sync.Mutex
+	// value is the fixed value to return from StorageAt.
+	// We'll assume StorageAt returns a 32-byte value representing an Ethereum address.
+	value common.Address
+}
+
+// BlockNumber returns 0.
+func (f *fakeEthClient) BlockNumber(ctx context.Context) (uint64, error) {
+	return 0, nil
+}
+
+// ChainID returns a zero-value chain ID.
+func (f *fakeEthClient) ChainID(ctx context.Context) (*big.Int, error) {
+	return big.NewInt(0), nil
+}
+
+// FilterLogs returns an empty slice of logs.
+func (f *fakeEthClient) FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]types.Log, error) {
+	return []types.Log{}, nil
+}
+
+// HeaderByNumber returns nil.
+func (f *fakeEthClient) HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error) {
+	return nil, nil
+}
+
+// SubscribeFilterLogs returns a nil subscription.
+func (f *fakeEthClient) SubscribeFilterLogs(ctx context.Context, query ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) {
+	return nil, nil
+}
+
+// TransactionByHash returns (nil, false, nil).
+func (f *fakeEthClient) TransactionByHash(ctx context.Context, txHash common.Hash) (*types.Transaction, bool, error) {
+	return nil, false, nil
+}
+
+// BlockByHash returns nil.
+func (f *fakeEthClient) BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error) {
+	return nil, nil
+}
+
+// StorageAt returns the byte representation of f.value.
+func (f *fakeEthClient) StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return f.value.Bytes(), nil
+}

consensus/wrapper/consensus.go

@@ -0,0 +1,207 @@
+package wrapper
+
+import (
+	"math/big"
+	"sync"
+
+	"github.com/scroll-tech/go-ethereum/common"
+	"github.com/scroll-tech/go-ethereum/consensus"
+	"github.com/scroll-tech/go-ethereum/consensus/clique"
+	"github.com/scroll-tech/go-ethereum/consensus/system_contract"
+	"github.com/scroll-tech/go-ethereum/core/state"
+	"github.com/scroll-tech/go-ethereum/core/types"
+	"github.com/scroll-tech/go-ethereum/rpc"
+)
+
+// UpgradableEngine implements consensus.Engine and acts as a middleware to dispatch
+// calls to either Clique or SystemContract consensus.
+type UpgradableEngine struct {
+	// forkBlock is the block number at which the switchover to SystemContract occurs.
+	isUpgraded func(uint64) bool
+
+	// clique is the original Clique consensus engine.
+	clique consensus.Engine
+
+	// system is the new SystemContract consensus engine.
+	system consensus.Engine
+}
+
+// NewUpgradableEngine constructs a new upgradable consensus middleware.
+func NewUpgradableEngine(isUpgraded func(uint64) bool, clique consensus.Engine, system consensus.Engine) *UpgradableEngine {
+	return &UpgradableEngine{
+		isUpgraded: isUpgraded,
+		clique:     clique,
+		system:     system,
+	}
+}
+
+// chooseEngine returns the appropriate consensus engine based on the header's number.
+func (ue *UpgradableEngine) chooseEngine(header *types.Header) consensus.Engine {
+	if ue.isUpgraded(header.Time) {
+		return ue.system
+	}
+	return ue.clique
+}
+
+// --------------------
+// Methods to implement consensus.Engine
+
+// Author returns the author of the block based on the header.
+func (ue *UpgradableEngine) Author(header *types.Header) (common.Address, error) {
+	return ue.chooseEngine(header).Author(header)
+}
+
+// VerifyHeader checks whether a header conforms to the consensus rules of the engine.
+func (ue *UpgradableEngine) VerifyHeader(chain consensus.ChainHeaderReader, header *types.Header, seal bool) error {
+	return ue.chooseEngine(header).VerifyHeader(chain, header, seal)
+}
+
+// VerifyHeaders verifies a batch of headers concurrently. In our use-case,
+// headers can only be all system, all clique, or start with clique and then switch once to system.
+func (ue *UpgradableEngine) VerifyHeaders(chain consensus.ChainHeaderReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) {
+	abort := make(chan struct{})
+	out := make(chan error)
+
+	// If there are no headers, return a closed error channel.
+	if len(headers) == 0 {
+		close(out)
+		return nil, out
+	}
+
+	// Choose engine for the first and last header.
+	firstEngine := ue.chooseEngine(headers[0])
+	lastEngine := ue.chooseEngine(headers[len(headers)-1])
+
+	// If the first header is system, then all headers must be system.
+	if firstEngine == ue.system {
+		return firstEngine.VerifyHeaders(chain, headers, seals)
+	}
+
+	// If first and last headers are both clique, then all headers are clique.
+	if firstEngine == lastEngine {
+		return firstEngine.VerifyHeaders(chain, headers, seals)
+	}
+
+	// Otherwise, headers start as clique then switch to system.  Since we assume
+	// a single switchover, find the first header that uses system.
+	splitIndex := 0
+	for i, header := range headers {
+		if ue.chooseEngine(header) == ue.system {
+			splitIndex = i
+			break
+		}
+	}
+	// It's expected that splitIndex is > 0.
+	cliqueHeaders := headers[:splitIndex]
+	cliqueSeals := seals[:splitIndex]
+	systemHeaders := headers[splitIndex:]
+	systemSeals := seals[splitIndex:]
+
+	// Create a wait group to merge results.
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	// Launch concurrent verifications.
+	go func() {
+		defer wg.Done()
+		_, cliqueResults := ue.clique.VerifyHeaders(chain, cliqueHeaders, cliqueSeals)
+		for err := range cliqueResults {
+			select {
+			case <-abort:
+				return
+			case out <- err:
+			}
+		}
+	}()
+
+	go func() {
+		defer wg.Done()
+		_, systemResults := ue.system.VerifyHeaders(chain, systemHeaders, systemSeals)
+		for err := range systemResults {
+			select {
+			case <-abort:
+				return
+			case out <- err:
+			}
+		}
+	}()
+
+	// Close the out channel when both verifications are complete.
+	go func() {
+		wg.Wait()
+		close(out)
+	}()
+
+	return abort, out
+}
+
+// Prepare prepares a block header for sealing.
+func (ue *UpgradableEngine) Prepare(chain consensus.ChainHeaderReader, header *types.Header) error {
+	return ue.chooseEngine(header).Prepare(chain, header)
+}
+
+// Seal instructs the engine to start sealing a block.
+func (ue *UpgradableEngine) Seal(chain consensus.ChainHeaderReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error {
+	return ue.chooseEngine(block.Header()).Seal(chain, block, results, stop)
+}
+
+// CalcDifficulty calculates the block difficulty if applicable.
+func (ue *UpgradableEngine) CalcDifficulty(chain consensus.ChainHeaderReader, time uint64, parent *types.Header) *big.Int {
+	return ue.chooseEngine(parent).CalcDifficulty(chain, time, parent)
+}
+
+// Finalize finalizes the block, applying any post-transaction rules.
+func (ue *UpgradableEngine) Finalize(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header) {
+	ue.chooseEngine(header).Finalize(chain, header, state, txs, uncles)
+}
+
+// FinalizeAndAssemble finalizes and assembles a new block.
+func (ue *UpgradableEngine) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {
+	return ue.chooseEngine(header).FinalizeAndAssemble(chain, header, state, txs, uncles, receipts)
+}
+
+// VerifyUncles verifies that no uncles are attached to the block.
+func (ue *UpgradableEngine) VerifyUncles(chain consensus.ChainReader, block *types.Block) error {
+	return ue.chooseEngine(block.Header()).VerifyUncles(chain, block)
+}
+
+// APIs returns any RPC APIs exposed by the consensus engine.
+func (ue *UpgradableEngine) APIs(chain consensus.ChainHeaderReader) []rpc.API {
+	// Determine the current chain head.
+	head := chain.CurrentHeader()
+	if head == nil {
+		// Fallback: return the clique APIs (or an empty slice) if we don't have a header.
+		return ue.clique.APIs(chain)
+	}
+
+	// Choose engine based on whether the chain head is before or after the fork block.
+	if ue.isUpgraded(head.Time) {
+		return ue.system.APIs(chain)
+	}
+	return ue.clique.APIs(chain)
+}
+
+// Close terminates the consensus engine.
+func (ue *UpgradableEngine) Close() error {
+	// Always close both engines.
+	if err := ue.clique.Close(); err != nil {
+		return err
+	}
+	return ue.system.Close()
+}
+
+// SealHash returns the hash of a block prior to it being sealed.
+func (ue *UpgradableEngine) SealHash(header *types.Header) common.Hash {
+	return ue.chooseEngine(header).SealHash(header)
+}
+
+// Authorize injects a private key into the consensus engine to mint new blocks
+// with.
+func (ue *UpgradableEngine) Authorize(signer common.Address, signFn clique.SignerFn, signFn2 system_contract.SignerFn) {
+	if cliqueEngine, ok := ue.clique.(*clique.Clique); ok {
+		cliqueEngine.Authorize(signer, signFn)
+	}
+	if sysContractEngine, ok := ue.system.(*system_contract.SystemContract); ok {
+		sysContractEngine.Authorize(signer, signFn2)
+	}
+}

core/types/block.go

@@ -86,6 +86,12 @@ type Header struct {
 	// BaseFee was added by EIP-1559 and is ignored in legacy headers.
 	BaseFee *big.Int `json:"baseFeePerGas" rlp:"optional"`
 
+	// BlockSignature was added by EuclidV2 to make Extra empty and is ignored during hashing
+	BlockSignature []byte `json:"-" rlp:"optional"`
+
+	// IsEuclidV2 was added by EuclidV2 to make Extra empty and is ignored during hashing
+	IsEuclidV2 bool `json:"-" rlp:"optional"`
+
 	// WithdrawalsHash was added by EIP-4895 and is ignored in legacy headers.
 	// Included for Ethereum compatibility in Scroll SDK
 	WithdrawalsHash *common.Hash `json:"withdrawalsRoot" rlp:"optional"`
@@ -101,6 +107,9 @@ type Header struct {
 	// ParentBeaconRoot was added by EIP-4788 and is ignored in legacy headers.
 	// Included for Ethereum compatibility in Scroll SDK
 	ParentBeaconRoot *common.Hash `json:"parentBeaconBlockRoot" rlp:"optional"`
+
+	//Hacky: used internally to mark the header as requested by the downloader at the deliver queue
+	Requested bool `json:"-" rlp:"-"`
 }
 
 // field type overrides for gencodec
@@ -118,7 +127,13 @@ type headerMarshaling struct {
 // Hash returns the block hash of the header, which is simply the keccak256 hash of its
 // RLP encoding.
 func (h *Header) Hash() common.Hash {
-	return rlpHash(h)
+	hCopy := CopyHeader(h)
+	hCopy.BlockSignature = nil
+	if hCopy.IsEuclidV2 {
+		hCopy.IsEuclidV2 = false
+		hCopy.Extra = nil
+	}
+	return rlpHash(hCopy)
 }
 
 var headerSize = common.StorageSize(reflect.TypeOf(Header{}).Size())
@@ -153,6 +168,14 @@ func (h *Header) SanityCheck() error {
 	return nil
 }
 
+// NetworkCompatibleEuclidV2Fields Enforces that both IsEuclidV2 and BlockSignature are empty when received over the network
+func (h *Header) NetworkCompatibleEuclidV2Fields() error {
+	if h.IsEuclidV2 || h.BlockSignature != nil {
+		return fmt.Errorf("header contains disallowed Euclid V2 fields (only used locally)")
+	}
+	return nil
+}
+
 // EmptyBody returns true if there is no additional 'body' to complete the header
 // that is: no transactions and no uncles.
 func (h *Header) EmptyBody() bool {
@@ -164,6 +187,22 @@ func (h *Header) EmptyReceipts() bool {
 	return h.ReceiptHash == EmptyRootHash
 }
 
+func (h *Header) PrepareForNetwork() {
+	if h.IsEuclidV2 {
+		h.IsEuclidV2 = false
+		h.Extra = h.BlockSignature
+		h.BlockSignature = nil
+	}
+}
+
+func (h *Header) PrepareFromNetwork(isEuclidV2 bool) {
+	if isEuclidV2 {
+		h.IsEuclidV2 = true
+		h.BlockSignature = h.Extra
+		h.Extra = nil
+	}
+}
+
 // Body is a simple (mutable, non-safe) data container for storing and moving
 // a block's data contents (transactions and uncles) together.
 type Body struct {
@@ -262,6 +301,10 @@ func CopyHeader(h *Header) *Header {
 		cpy.Extra = make([]byte, len(h.Extra))
 		copy(cpy.Extra, h.Extra)
 	}
+	if len(h.BlockSignature) > 0 {
+		cpy.BlockSignature = make([]byte, len(h.BlockSignature))
+		copy(cpy.BlockSignature, h.BlockSignature)
+	}
 	return &cpy
 }
 
@@ -460,6 +503,22 @@ func (b *Block) CountL2Tx() int {
 	return count
 }
 
+func (b *Block) CopyBlockDeepWithHeader(header *Header) *Block {
+	return &Block{
+		header:       CopyHeader(header),
+		uncles:       b.uncles,       // slice reference (the slice header is copied but the underlying array is shared)
+		transactions: b.transactions, // reference copy
+		// caches (atomic.Value fields) are reused as-is; if necessary, you might want to load and store their values
+		hash:       b.hash,
+		size:       b.size,
+		l1MsgCount: b.l1MsgCount,
+		// Other fields are copied by value (td is a pointer so it's shared)
+		td:           b.td,
+		ReceivedAt:   b.ReceivedAt,
+		ReceivedFrom: b.ReceivedFrom,
+	}
+}
+
 type Blocks []*Block
 
 type BlockWithRowConsumption struct {

eth/backend.go

@@ -32,6 +32,8 @@ import (
 	"github.com/scroll-tech/go-ethereum/common/hexutil"
 	"github.com/scroll-tech/go-ethereum/consensus"
 	"github.com/scroll-tech/go-ethereum/consensus/clique"
+	"github.com/scroll-tech/go-ethereum/consensus/system_contract"
+	"github.com/scroll-tech/go-ethereum/consensus/wrapper"
 	"github.com/scroll-tech/go-ethereum/core"
 	"github.com/scroll-tech/go-ethereum/core/bloombits"
 	"github.com/scroll-tech/go-ethereum/core/rawdb"
@@ -156,7 +158,7 @@ func New(stack *node.Node, config *ethconfig.Config, l1Client l1.Client) (*Ether
 		chainDb:           chainDb,
 		eventMux:          stack.EventMux(),
 		accountManager:    stack.AccountManager(),
-		engine:            ethconfig.CreateConsensusEngine(stack, chainConfig, &ethashConfig, config.Miner.Notify, config.Miner.Noverify, chainDb),
+		engine:            ethconfig.CreateConsensusEngine(stack, chainConfig, &ethashConfig, config.Miner.Notify, config.Miner.Noverify, chainDb, l1Client),
 		closeBloomHandler: make(chan struct{}),
 		networkID:         config.NetworkId,
 		gasPrice:          config.Miner.GasPrice,
@@ -279,6 +281,7 @@ func New(stack *node.Node, config *ethconfig.Config, l1Client l1.Client) (*Ether
 
 	config.Miner.SigningDisabled = config.DA.ProduceBlocks
 	eth.miner = miner.New(eth, &config.Miner, eth.blockchain.Config(), eth.EventMux(), eth.engine, eth.isLocalBlock, config.EnableDASyncing && !config.DA.ProduceBlocks)
+	// Some of the extraData is used with Clique consensus (before EuclidV2). After EuclidV2 we use SystemContract consensus where this is overridden when creating a block.
 	eth.miner.SetExtra(makeExtraData(config.Miner.ExtraData))
 
 	eth.APIBackend = &EthAPIBackend{stack.Config().ExtRPCEnabled(), stack.Config().AllowUnprotectedTxs, eth, nil}
@@ -528,13 +531,27 @@ func (s *Ethereum) StartMining(threads int) error {
 			log.Error("Cannot start mining without etherbase", "err", err)
 			return fmt.Errorf("etherbase missing: %v", err)
 		}
-		if clique, ok := s.engine.(*clique.Clique); ok {
+		if wrapper, ok := s.engine.(*wrapper.UpgradableEngine); ok {
+			wallet, err := s.accountManager.Find(accounts.Account{Address: eb})
+			if wallet == nil || err != nil {
+				log.Error("Etherbase account unavailable locally", "err", err)
+				return fmt.Errorf("signer missing: %v", err)
+			}
+			wrapper.Authorize(eb, wallet.SignData, wallet.SignData)
+		} else if clique, ok := s.engine.(*clique.Clique); ok {
 			wallet, err := s.accountManager.Find(accounts.Account{Address: eb})
 			if wallet == nil || err != nil {
 				log.Error("Etherbase account unavailable locally", "err", err)
 				return fmt.Errorf("signer missing: %v", err)
 			}
 			clique.Authorize(eb, wallet.SignData)
+		} else if systemContract, ok := s.engine.(*system_contract.SystemContract); ok {
+			wallet, err := s.accountManager.Find(accounts.Account{Address: eb})
+			if wallet == nil || err != nil {
+				log.Error("Etherbase account unavailable locally", "err", err)
+				return fmt.Errorf("signer missing: %v", err)
+			}
+			systemContract.Authorize(eb, wallet.SignData)
 		}
 		// If mining is started, we can disable the transaction rejection mechanism
 		// introduced to speed sync times.

eth/downloader/downloader.go

@@ -702,9 +702,11 @@ func (d *Downloader) fetchHead(p *peerConnection) (head *types.Header, pivot *ty
 // calculateRequestSpan calculates what headers to request from a peer when trying to determine the
 // common ancestor.
 // It returns parameters to be used for peer.RequestHeadersByNumber:
+//
 //	from - starting block number
 //	count - number of headers to request
 //	skip - number of headers to skip
+//
 // and also returns 'max', the last block which is expected to be returned by the remote peers,
 // given the (from,count,skip)
 func calculateRequestSpan(remoteHeight, localHeight uint64) (int64, int, int, uint64) {

eth/downloader/queue.go

@@ -477,6 +477,7 @@ func (q *queue) ReserveReceipts(p *peerConnection, count int) (*fetchRequest, bo
 // to access the queue, so they already need a lock anyway.
 //
 // Returns:
+//
 //	item     - the fetchRequest
 //	progress - whether any progress was made
 //	throttle - if the caller should throttle for a while
@@ -705,6 +706,11 @@ func (q *queue) DeliverHeaders(id string, headers []*types.Header, headerProcCh
 	headerReqTimer.UpdateSince(request.Time)
 	delete(q.headerPendPool, id)
 
+	// Hacky: mark that the header was explicitly requested
+	for _, header := range headers {
+		header.Requested = true
+	}
+
 	// Ensure headers can be mapped onto the skeleton chain
 	target := q.headerTaskPool[request.From].Hash()
 
@@ -842,6 +848,11 @@ func (q *queue) deliver(id string, taskPool map[common.Hash]*types.Header,
 	reqTimer.UpdateSince(request.Time)
 	delete(pendPool, id)
 
+	// Hacky: mark that the header was explicitly requested
+	for _, header := range request.Headers {
+		header.Requested = true
+	}
+
 	// If no data items were retrieved, mark them as unavailable for the origin peer
 	if results == 0 {
 		for _, header := range request.Headers {

eth/downloader/resultstore.go

@@ -71,6 +71,7 @@ func (r *resultStore) SetThrottleThreshold(threshold uint64) uint64 {
 // wants to reserve headers for fetching.
 //
 // It returns the following:
+//
 //	stale     - if true, this item is already passed, and should not be requested again
 //	throttled - if true, the store is at capacity, this particular header is not prio now
 //	item      - the result to store data into

eth/ethconfig/config.go

@@ -18,6 +18,7 @@
 package ethconfig
 
 import (
+	"context"
 	"math/big"
 	"os"
 	"os/user"
@@ -25,10 +26,13 @@ import (
 	"runtime"
 	"time"
 
+	"github.com/scroll-tech/go-ethereum/consensus/wrapper"
+
 	"github.com/scroll-tech/go-ethereum/common"
 	"github.com/scroll-tech/go-ethereum/consensus"
 	"github.com/scroll-tech/go-ethereum/consensus/clique"
 	"github.com/scroll-tech/go-ethereum/consensus/ethash"
+	"github.com/scroll-tech/go-ethereum/consensus/system_contract"
 	"github.com/scroll-tech/go-ethereum/core"
 	"github.com/scroll-tech/go-ethereum/eth/downloader"
 	"github.com/scroll-tech/go-ethereum/eth/gasprice"
@@ -38,6 +42,7 @@ import (
 	"github.com/scroll-tech/go-ethereum/node"
 	"github.com/scroll-tech/go-ethereum/params"
 	"github.com/scroll-tech/go-ethereum/rollup/da_syncer"
+	"github.com/scroll-tech/go-ethereum/rollup/sync_service"
 )
 
 // FullNodeGPO contains default gasprice oracle settings for full node.
@@ -228,11 +233,27 @@ type Config struct {
 }
 
 // CreateConsensusEngine creates a consensus engine for the given chain configuration.
-func CreateConsensusEngine(stack *node.Node, chainConfig *params.ChainConfig, config *ethash.Config, notify []string, noverify bool, db ethdb.Database) consensus.Engine {
+func CreateConsensusEngine(stack *node.Node, chainConfig *params.ChainConfig, config *ethash.Config, notify []string, noverify bool, db ethdb.Database, l1Client sync_service.EthClient) consensus.Engine {
-	// If proof-of-authority is requested, set it up
+	// Case 1: Both SystemContract and Clique are defined: create an upgradable engine.
+	if chainConfig.SystemContract != nil && chainConfig.Clique != nil {
+		cliqueEngine := clique.New(chainConfig.Clique, db)
+		sysEngine := system_contract.New(context.Background(), chainConfig.SystemContract, l1Client)
+		sysEngine.Start()
+		return wrapper.NewUpgradableEngine(chainConfig.IsEuclidV2, cliqueEngine, sysEngine)
+	}
+
+	// Case 2: Only the Clique engine is defined.
 	if chainConfig.Clique != nil {
 		return clique.New(chainConfig.Clique, db)
 	}
+
+	// Case 3: Only the SystemContract engine is defined.
+	if chainConfig.SystemContract != nil {
+		sysEngine := system_contract.New(context.Background(), chainConfig.SystemContract, l1Client)
+		sysEngine.Start()
+		return sysEngine
+	}
+
 	// Otherwise assume proof-of-work
 	switch config.PowMode {
 	case ethash.ModeFake:

eth/handler_eth_test.go

@@ -24,6 +24,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/scroll-tech/go-ethereum/crypto"
+
 	"github.com/scroll-tech/go-ethereum/common"
 	"github.com/scroll-tech/go-ethereum/consensus/ethash"
 	"github.com/scroll-tech/go-ethereum/core"
@@ -48,7 +50,26 @@ type testEthHandler struct {
 	txBroadcasts    event.Feed
 }
 
-func (h *testEthHandler) Chain() *core.BlockChain              { panic("no backing chain") }
+func (h *testEthHandler) Chain() *core.BlockChain {
+	chainConfig := &params.ChainConfig{}
+	engine := ethash.NewFaker()
+	chaindb := rawdb.NewMemoryDatabase()
+
+	// Import the canonical chain
+	cacheConfig := &core.CacheConfig{}
+	key1, _ := crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+	addr1 := crypto.PubkeyToAddress(key1.PublicKey)
+	genesis := core.GenesisBlockForTesting(chaindb, addr1, big.NewInt(1000000))
+	rawdb.WriteBlock(chaindb, genesis)
+	rawdb.WriteCanonicalHash(chaindb, genesis.Hash(), genesis.NumberU64())
+	rawdb.WriteHeadBlockHash(chaindb, genesis.Hash())
+
+	chain, err := core.NewBlockChain(chaindb, cacheConfig, chainConfig, engine, vm.Config{}, nil, nil)
+	if err != nil {
+		panic(fmt.Sprintf("failed to create chain: %v", err))
+	}
+	return chain
+}
 func (h *testEthHandler) StateBloom() *trie.SyncBloom          { panic("no backing state bloom") }
 func (h *testEthHandler) TxPool() eth.TxPool                   { panic("no backing tx pool") }
 func (h *testEthHandler) AcceptTxs() bool                      { return true }
@@ -505,8 +526,7 @@ func testCheckpointChallenge(t *testing.T, syncmode downloader.SyncMode, checkpo
 	var response *types.Header
 	if checkpoint {
 		number := (uint64(rand.Intn(500))+1)*params.CHTFrequency - 1
-		response = &types.Header{Number: big.NewInt(int64(number)), Extra: []byte("valid")}
+		response = &types.Header{Number: big.NewInt(int64(number))}
-
 		handler.handler.checkpointNumber = number
 		handler.handler.checkpointHash = response.Hash()
 	}
@@ -554,6 +574,7 @@ func testCheckpointChallenge(t *testing.T, syncmode downloader.SyncMode, checkpo
 				query.Origin.Number, query.Amount, query.Skip, query.Reverse,
 				response.Number.Uint64(), 1, 0, false)
 		}
+
 		// Create a block to reply to the challenge if no timeout is simulated.
 		if !timeout {
 			if empty {
@@ -565,7 +586,8 @@ func testCheckpointChallenge(t *testing.T, syncmode downloader.SyncMode, checkpo
 					t.Fatalf("failed to answer challenge: %v", err)
 				}
 			} else {
-				if err := remote.ReplyBlockHeaders(request.RequestId, []*types.Header{{Number: response.Number}}); err != nil {
+				number := new(big.Int).Add(response.Number, big.NewInt(1)) // mismatching headers to same request
+				if err := remote.ReplyBlockHeaders(request.RequestId, []*types.Header{{Number: number}}); err != nil {
 					t.Fatalf("failed to answer challenge: %v", err)
 				}
 			}
@@ -573,7 +595,6 @@ func testCheckpointChallenge(t *testing.T, syncmode downloader.SyncMode, checkpo
 	}
 	// Wait until the test timeout passes to ensure proper cleanup
 	time.Sleep(syncChallengeTimeout + 300*time.Millisecond)
-
 	// Verify that the remote peer is maintained or dropped.
 	if drop {
 		<-handlerDone

eth/protocols/eth/handlers.go

@@ -24,6 +24,7 @@ import (
 	"github.com/scroll-tech/go-ethereum/core/types"
 	"github.com/scroll-tech/go-ethereum/log"
 	"github.com/scroll-tech/go-ethereum/metrics"
+	"github.com/scroll-tech/go-ethereum/p2p"
 	"github.com/scroll-tech/go-ethereum/rlp"
 	"github.com/scroll-tech/go-ethereum/trie"
 )
@@ -266,6 +267,16 @@ func handleNewBlock(backend Backend, msg Decoder, peer *Peer) error {
 	if err := msg.Decode(ann); err != nil {
 		return fmt.Errorf("%w: message %v: %v", errDecode, msg, err)
 	}
+
+	hCopy := ann.Block.Header()
+	if err := hCopy.NetworkCompatibleEuclidV2Fields(); err != nil {
+		peer.Peer.Disconnect(p2p.DiscUselessPeer)
+		return err
+	}
+
+	hCopy.PrepareFromNetwork(backend.Chain().Config().IsEuclidV2(hCopy.Time))
+	ann.Block = ann.Block.CopyBlockDeepWithHeader(hCopy)
+
 	if err := ann.sanityCheck(); err != nil {
 		return err
 	}
@@ -294,6 +305,17 @@ func handleBlockHeaders66(backend Backend, msg Decoder, peer *Peer) error {
 	}
 	requestTracker.Fulfil(peer.id, peer.version, BlockHeadersMsg, res.RequestId)
 
+	headersCopy := make([]*types.Header, 0, len(res.BlockHeadersPacket))
+	for _, header := range res.BlockHeadersPacket {
+		hCopy := types.CopyHeader(header)
+		if err := hCopy.NetworkCompatibleEuclidV2Fields(); err != nil {
+			peer.Peer.Disconnect(p2p.DiscUselessPeer)
+			return err
+		}
+		hCopy.PrepareFromNetwork(backend.Chain().Config().IsEuclidV2(header.Time))
+		headersCopy = append(headersCopy, hCopy)
+	}
+	res.BlockHeadersPacket = headersCopy
 	return backend.Handle(peer, &res.BlockHeadersPacket)
 }
 

eth/protocols/eth/peer.go

@@ -277,6 +277,9 @@ func (p *Peer) AsyncSendNewBlockHash(block *types.Block) {
 func (p *Peer) SendNewBlock(block *types.Block, td *big.Int) error {
 	// Mark all the block hash as known, but ensure we don't overflow our limits
 	p.knownBlocks.Add(block.Hash())
+	hCopy := block.Header()
+	hCopy.PrepareForNetwork()
+	block = block.CopyBlockDeepWithHeader(hCopy)
 	return p2p.Send(p.rw, NewBlockMsg, &NewBlockPacket{
 		Block: block,
 		TD:    td,
@@ -297,6 +300,14 @@ func (p *Peer) AsyncSendNewBlock(block *types.Block, td *big.Int) {
 
 // ReplyBlockHeaders is the eth/66 version of SendBlockHeaders.
 func (p *Peer) ReplyBlockHeaders(id uint64, headers []*types.Header) error {
+	headersCopy := make([]*types.Header, 0, len(headers))
+	for _, header := range headers {
+		hCopy := types.CopyHeader(header)
+		hCopy.PrepareForNetwork()
+		headersCopy = append(headersCopy, hCopy)
+	}
+	headers = headersCopy
+
 	return p2p.Send(p.rw, BlockHeadersMsg, BlockHeadersPacket66{
 		RequestId:          id,
 		BlockHeadersPacket: headers,

eth/protocols/snap/sync_test.go

@@ -370,6 +370,7 @@ func createStorageRequestResponse(t *testPeer, root common.Hash, accounts []comm
 }
 
 //	the createStorageRequestResponseAlwaysProve tests a cornercase, where it always
+//
 // supplies the proof for the last account, even if it is 'complete'.h
 func createStorageRequestResponseAlwaysProve(t *testPeer, root common.Hash, accounts []common.Hash, bOrigin, bLimit []byte, max uint64) (hashes [][]common.Hash, slots [][][]byte, proofs [][]byte) {
 	var size uint64

eth/tracers/js/internal/tracers/assets.go

@@ -388,11 +388,13 @@ const AssetDebug = false
 // directory embedded in the file by go-bindata.
 // For example if you run go-bindata on data/... and data contains the
 // following hierarchy:
+//
 //	data/
 //	  foo.txt
 //	  img/
 //	    a.png
 //	    b.png
+//
 // then AssetDir("data") would return []string{"foo.txt", "img"},
 // AssetDir("data/img") would return []string{"a.png", "b.png"},
 // AssetDir("foo.txt") and AssetDir("notexist") would return an error, and

eth/tracers/native/4byte.go

@@ -38,6 +38,7 @@ func init() {
 // a reversed signature can be matched against the size of the data.
 //
 // Example:
+//
 //	> debug.traceTransaction( "0x214e597e35da083692f5386141e69f47e973b2c56e7a8073b1ea08fd7571e9de", {tracer: "4byteTracer"})
 //	{
 //	  0x27dc297e-128: 1,

go.mod

@@ -22,7 +22,7 @@ require (
 	github.com/edsrzf/mmap-go v1.0.0
 	github.com/ethereum/c-kzg-4844/bindings/go v0.0.0-20230126171313-363c7d7593b4
 	github.com/fatih/color v1.7.0
-	github.com/fjl/memsize v0.0.0-20190710130421-bcb5799ab5e5
+	github.com/fjl/memsize v0.0.2
 	github.com/gballet/go-libpcsclite v0.0.0-20190607065134-2772fd86a8ff
 	github.com/go-stack/stack v1.8.1
 	github.com/golang/protobuf v1.4.3

go.sum

@@ -134,8 +134,8 @@ github.com/ethereum/c-kzg-4844/bindings/go v0.0.0-20230126171313-363c7d7593b4 h1
 github.com/ethereum/c-kzg-4844/bindings/go v0.0.0-20230126171313-363c7d7593b4/go.mod h1:y4GA2JbAUama1S4QwYjC2hefgGLU8Ul0GMtL/ADMF1c=
 github.com/fatih/color v1.7.0 h1:DkWD4oS2D8LGGgTQ6IvwJJXSL5Vp2ffcQg58nFV38Ys=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
-github.com/fjl/memsize v0.0.0-20190710130421-bcb5799ab5e5 h1:FtmdgXiUlNeRsoNMFlKLDt+S+6hbjVMEW6RGQ7aUf7c=
+github.com/fjl/memsize v0.0.2 h1:27txuSD9or+NZlnOWdKUxeBzTAUkWCVh+4Gf2dWFOzA=
-github.com/fjl/memsize v0.0.0-20190710130421-bcb5799ab5e5/go.mod h1:VvhXpOYNQvB+uIk2RvXzuaQtkQJzzIx6lSBe1xv7hi0=
+github.com/fjl/memsize v0.0.2/go.mod h1:VvhXpOYNQvB+uIk2RvXzuaQtkQJzzIx6lSBe1xv7hi0=
 github.com/fogleman/gg v1.2.1-0.20190220221249-0403632d5b90/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fsnotify/fsnotify v1.4.9 h1:hsms1Qyu0jgnwNXIxa+/V/PDsU6CfLf6CNO8H7IWoS4=

les/api_test.go

@@ -498,7 +498,7 @@ func newLesClientService(ctx *adapters.ServiceContext, stack *node.Node) (node.L
 	config := ethconfig.Defaults
 	config.SyncMode = (ethdownloader.SyncMode)(downloader.LightSync)
 	config.Ethash.PowMode = ethash.ModeFake
-	return New(stack, &config)
+	return New(stack, &config, nil)
 }
 
 func newLesServerService(ctx *adapters.ServiceContext, stack *node.Node) (node.Lifecycle, error) {

les/client.go

@@ -46,6 +46,7 @@ import (
 	"github.com/scroll-tech/go-ethereum/p2p/enr"
 	"github.com/scroll-tech/go-ethereum/params"
 	"github.com/scroll-tech/go-ethereum/rlp"
+	"github.com/scroll-tech/go-ethereum/rollup/sync_service"
 	"github.com/scroll-tech/go-ethereum/rpc"
 )
 
@@ -79,7 +80,7 @@ type LightEthereum struct {
 }
 
 // New creates an instance of the light client.
-func New(stack *node.Node, config *ethconfig.Config) (*LightEthereum, error) {
+func New(stack *node.Node, config *ethconfig.Config, l1Client sync_service.EthClient) (*LightEthereum, error) {
 	chainDb, err := stack.OpenDatabase("lightchaindata", config.DatabaseCache, config.DatabaseHandles, "eth/db/chaindata/", false)
 	if err != nil {
 		return nil, err
@@ -109,7 +110,7 @@ func New(stack *node.Node, config *ethconfig.Config) (*LightEthereum, error) {
 		eventMux:       stack.EventMux(),
 		reqDist:        newRequestDistributor(peers, &mclock.System{}),
 		accountManager: stack.AccountManager(),
-		engine:         ethconfig.CreateConsensusEngine(stack, chainConfig, &config.Ethash, nil, false, chainDb),
+		engine:         ethconfig.CreateConsensusEngine(stack, chainConfig, &config.Ethash, nil, false, chainDb, l1Client),
 		bloomRequests:  make(chan chan *bloombits.Retrieval),
 		bloomIndexer:   core.NewBloomIndexer(chainDb, params.BloomBitsBlocksClient, params.HelperTrieConfirmations),
 		p2pServer:      stack.Server(),

les/downloader/queue.go

@@ -705,6 +705,11 @@ func (q *queue) DeliverHeaders(id string, headers []*types.Header, headerProcCh
 	headerReqTimer.UpdateSince(request.Time)
 	delete(q.headerPendPool, id)
 
+	// Hacky: mark that the header was explicitly requested
+	for _, header := range headers {
+		header.Requested = true
+	}
+
 	// Ensure headers can be mapped onto the skeleton chain
 	target := q.headerTaskPool[request.From].Hash()
 
@@ -842,6 +847,11 @@ func (q *queue) deliver(id string, taskPool map[common.Hash]*types.Header,
 	reqTimer.UpdateSince(request.Time)
 	delete(pendPool, id)
 
+	// Hacky: mark that the header was explicitly requested
+	for _, header := range request.Headers {
+		header.Requested = true
+	}
+
 	// If no data items were retrieved, mark them as unavailable for the origin peer
 	if results == 0 {
 		for _, header := range request.Headers {

miner/scroll_worker.go

@@ -25,6 +25,8 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/scroll-tech/go-ethereum/consensus/system_contract"
+
 	"github.com/scroll-tech/go-ethereum/common"
 	"github.com/scroll-tech/go-ethereum/consensus"
 	"github.com/scroll-tech/go-ethereum/consensus/misc"
@@ -358,8 +360,11 @@ func (w *worker) mainLoop() {
 		}
 
 		var retryableCommitError *retryableCommitError
-		if errors.As(err, &retryableCommitError) {
+		if errors.As(err, &retryableCommitError) || errors.Is(err, system_contract.ErrUnauthorizedSigner) {
 			log.Warn("failed to commit to a block, retrying", "err", err)
+			if errors.Is(err, system_contract.ErrUnauthorizedSigner) {
+				time.Sleep(5 * time.Second) // half the time it takes for the system contract consensus to read and update the address locally.
+			}
 			if _, err = w.tryCommitNewWork(time.Now(), w.current.header.ParentHash, w.current.reorging, w.current.reorgReason); err != nil {
 				continue
 			}

mobile/geth.go

@@ -194,7 +194,7 @@ func NewNode(datadir string, config *NodeConfig) (stack *Node, _ error) {
 		ethConf.SyncMode = downloader.LightSync
 		ethConf.NetworkId = uint64(config.EthereumNetworkID)
 		ethConf.DatabaseCache = config.EthereumDatabaseCache
-		lesBackend, err := les.New(rawStack, &ethConf)
+		lesBackend, err := les.New(rawStack, &ethConf, nil)
 		if err != nil {
 			return nil, fmt.Errorf("ethereum init: %v", err)
 		}

params/config.go

@@ -650,6 +650,7 @@ type ChainConfig struct {
 	// Various consensus engines
 	Ethash         *EthashConfig         `json:"ethash,omitempty"`
 	Clique         *CliqueConfig         `json:"clique,omitempty"`
+	SystemContract *SystemContractConfig `json:"systemContract,omitempty"`
 
 	// Scroll genesis extension: enable scroll rollup-related traces & state transition
 	Scroll ScrollConfig `json:"scroll,omitempty"`
@@ -771,6 +772,21 @@ func (c *CliqueConfig) String() string {
 	return "clique"
 }
 
+// SystemContractConfig is the consensus engine configs for rollup sequencer sealing.
+type SystemContractConfig struct {
+	Period uint64 `json:"period"` // Number of seconds between blocks to enforce
+
+	SystemContractAddress common.Address `json:"system_contract_address"` // address of system contract on L1
+	SystemContractSlot    common.Hash    `json:"system_contract_slot"`    // slot of signer address in system contract on L1
+
+	RelaxedPeriod bool `json:"relaxed_period"` // Relaxes the period to be just an upper bound
+}
+
+// String implements the stringer interface, returning the consensus engine details.
+func (c *SystemContractConfig) String() string {
+	return "system_contract"
+}
+
 // String implements the fmt.Stringer interface.
 func (c *ChainConfig) String() string {
 	var engine interface{}

params/version.go

@@ -24,7 +24,7 @@ import (
 const (
 	VersionMajor = 5         // Major version component of the current release
 	VersionMinor = 8         // Minor version component of the current release
-	VersionPatch = 13        // Patch version component of the current release
+	VersionPatch = 14        // Patch version component of the current release
 	VersionMeta  = "mainnet" // Version metadata to append to the version string
 )
 

rollup/l1/types.go

@@ -19,6 +19,7 @@ type Client interface {
 	TransactionByHash(ctx context.Context, txHash common.Hash) (tx *types.Transaction, isPending bool, err error)
 	BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error)
 	CallContract(ctx context.Context, msg ethereum.CallMsg, blockNumber *big.Int) ([]byte, error)
+	StorageAt(ctx context.Context, contract common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error)
 }
 
 type MockNopClient struct{}
@@ -58,3 +59,7 @@ func (m *MockNopClient) BlockByHash(ctx context.Context, hash common.Hash) (*typ
 func (m *MockNopClient) CallContract(ctx context.Context, msg ethereum.CallMsg, blockNumber *big.Int) ([]byte, error) {
 	return nil, nil
 }
+
+func (m *MockNopClient) StorageAt(ctx context.Context, contract common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) {
+	return nil, nil
+}

rollup/sync_service/types.go

@@ -19,4 +19,5 @@ type EthClient interface {
 	SubscribeFilterLogs(ctx context.Context, query ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error)
 	TransactionByHash(ctx context.Context, txHash common.Hash) (tx *types.Transaction, isPending bool, err error)
 	BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error)
+	StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error)
 }