all: add stateless verifications

Author: jwasinger

cmd/utils/stateless/stateless.go

@@ -0,0 +1,86 @@
+package stateless
+
+import (
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/consensus/beacon"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/triedb"
+)
+
+// StatelessExecute executes the block contained in the Witness returning the post state root or an error
+func StatelessExecute(chainCfg *params.ChainConfig, witness *state.Witness) (root common.Hash, err error) {
+	rawDb := rawdb.NewMemoryDatabase()
+	if err := witness.PopulateDB(rawDb); err != nil {
+		return common.Hash{}, err
+	}
+	blob := rawdb.ReadAccountTrieNode(rawDb, nil)
+	prestateRoot := crypto.Keccak256Hash(blob)
+
+	db, err := state.New(prestateRoot, state.NewDatabaseWithConfig(rawDb, triedb.PathDefaults), nil)
+	if err != nil {
+		return common.Hash{}, err
+	}
+	engine := beacon.New(ethash.NewFaker())
+	validator := core.NewBlockValidator(chainCfg, nil, engine)
+	processor := core.NewStateProcessor(chainCfg, nil, engine)
+
+	receipts, _, usedGas, err := processor.Process(witness.Block, db, vm.Config{}, witness)
+	if err != nil {
+		return common.Hash{}, err
+	}
+
+	// compute the state root.
+	if root, err = validator.ValidateState(witness.Block, db, receipts, usedGas, false); err != nil {
+		return common.Hash{}, err
+	}
+	return root, nil
+}
+
+// BuildStatelessProof executes a block, collecting the accessed pre-state into
+// a Witness.  The RLP-encoded witness is returned.
+func BuildStatelessProof(blockHash common.Hash, bc *core.BlockChain) ([]byte, error) {
+	block := bc.GetBlockByHash(blockHash)
+	if block == nil {
+		return nil, fmt.Errorf("non-existent block %x", blockHash)
+	} else if block.NumberU64() == 0 {
+		return nil, fmt.Errorf("cannot build a stateless proof of the genesis block")
+	}
+	parentHash := block.ParentHash()
+	parent := bc.GetBlockByHash(parentHash)
+	if parent == nil {
+		return nil, fmt.Errorf("block %x parent not present", parentHash)
+	}
+
+	db, err := bc.StateAt(parent.Header().Root)
+	if err != nil {
+		return nil, err
+	}
+	db.EnableWitnessBuilding()
+	if bc.Snapshots() != nil {
+		db.StartPrefetcher("BuildStatelessProof", false)
+		defer db.StopPrefetcher()
+	}
+	stateProcessor := core.NewStateProcessor(bc.Config(), bc, bc.Engine())
+	_, _, _, err = stateProcessor.Process(block, db, vm.Config{}, nil)
+	if err != nil {
+		return nil, err
+	}
+	if _, err = db.Commit(block.NumberU64(), true); err != nil {
+		return nil, err
+	}
+	proof := db.Witness()
+	proof.Block = block
+	enc, err := proof.EncodeRLP()
+	if err != nil {
+		return nil, err
+	}
+	return enc, nil
+}

core/block_validator.go

@@ -20,6 +20,7 @@ import (
 	"errors"
 	"fmt"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -121,28 +122,31 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 
 // ValidateState validates the various changes that happen after a state transition,
 // such as amount of used gas, the receipt roots and the state root itself.
-func (v *BlockValidator) ValidateState(block *types.Block, statedb *state.StateDB, receipts types.Receipts, usedGas uint64) error {
+// If validateRemoteRoot is false, the provided block header's root is not asserted to be equal to the one computed from
+// execution.
+func (v *BlockValidator) ValidateState(block *types.Block, statedb *state.StateDB, receipts types.Receipts, usedGas uint64, checkRemoteRoot bool) (root common.Hash, err error) {
 	header := block.Header()
 	if block.GasUsed() != usedGas {
-		return fmt.Errorf("invalid gas used (remote: %d local: %d)", block.GasUsed(), usedGas)
+		return root, fmt.Errorf("invalid gas used (remote: %d local: %d)", block.GasUsed(), usedGas)
 	}
 	// Validate the received block's bloom with the one derived from the generated receipts.
 	// For valid blocks this should always validate to true.
 	rbloom := types.CreateBloom(receipts)
 	if rbloom != header.Bloom {
-		return fmt.Errorf("invalid bloom (remote: %x  local: %x)", header.Bloom, rbloom)
+		return root, fmt.Errorf("invalid bloom (remote: %x  local: %x)", header.Bloom, rbloom)
 	}
 	// The receipt Trie's root (R = (Tr [[H1, R1], ... [Hn, Rn]]))
 	receiptSha := types.DeriveSha(receipts, trie.NewStackTrie(nil))
 	if receiptSha != header.ReceiptHash {
-		return fmt.Errorf("invalid receipt root hash (remote: %x local: %x)", header.ReceiptHash, receiptSha)
+		return root, fmt.Errorf("invalid receipt root hash (remote: %x local: %x)", header.ReceiptHash, receiptSha)
 	}
-	// Validate the state root against the received state root and throw
-	// an error if they don't match.
-	if root := statedb.IntermediateRoot(v.config.IsEIP158(header.Number)); header.Root != root {
-		return fmt.Errorf("invalid merkle root (remote: %x local: %x) dberr: %w", header.Root, root, statedb.Error())
+	// Compute the state root and if enabled, check it against the
+	// received state root and throw an error if they don't match.
+	root = statedb.IntermediateRoot(v.config.IsEIP158(header.Number))
+	if checkRemoteRoot && header.Root != root {
+		return root, fmt.Errorf("invalid merkle root (remote: %x local: %x) dberr: %w", header.Root, root, statedb.Error())
 	}
-	return nil
+	return root, nil
 }
 
 // CalcGasLimit computes the gas limit of the next block after parent. It aims

core/blockchain.go

@@ -1916,15 +1916,15 @@ func (bc *BlockChain) processBlock(block *types.Block, statedb *state.StateDB, s
 
 	// Process block using the parent state as reference point
 	pstart := time.Now()
-	receipts, logs, usedGas, err := bc.processor.Process(block, statedb, bc.vmConfig)
+	receipts, logs, usedGas, err := bc.processor.Process(block, statedb, bc.vmConfig, nil)
 	if err != nil {
 		bc.reportBlock(block, receipts, err)
 		return nil, err
 	}
 	ptime := time.Since(pstart)
 
 	vstart := time.Now()
-	if err := bc.validator.ValidateState(block, statedb, receipts, usedGas); err != nil {
+	if _, err := bc.validator.ValidateState(block, statedb, receipts, usedGas, true); err != nil {
 		bc.reportBlock(block, receipts, err)
 		return nil, err
 	}

core/blockchain_test.go

@@ -163,12 +163,12 @@ func testBlockChainImport(chain types.Blocks, blockchain *BlockChain) error {
 		if err != nil {
 			return err
 		}
-		receipts, _, usedGas, err := blockchain.processor.Process(block, statedb, vm.Config{})
+		receipts, _, usedGas, err := blockchain.processor.Process(block, statedb, vm.Config{}, nil)
 		if err != nil {
 			blockchain.reportBlock(block, receipts, err)
 			return err
 		}
-		err = blockchain.validator.ValidateState(block, statedb, receipts, usedGas)
+		_, err = blockchain.validator.ValidateState(block, statedb, receipts, usedGas, true)
 		if err != nil {
 			blockchain.reportBlock(block, receipts, err)
 			return err

core/chain_makers.go

@@ -99,7 +99,7 @@ func (b *BlockGen) Difficulty() *big.Int {
 func (b *BlockGen) SetParentBeaconRoot(root common.Hash) {
 	b.header.ParentBeaconRoot = &root
 	var (
-		blockContext = NewEVMBlockContext(b.header, b.cm, &b.header.Coinbase)
+		blockContext = NewEVMBlockContext(b.header, b.cm, &b.header.Coinbase, nil)
 		vmenv        = vm.NewEVM(blockContext, vm.TxContext{}, b.statedb, b.cm.config, vm.Config{})
 	)
 	ProcessBeaconBlockRoot(root, vmenv, b.statedb)

core/evm.go

@@ -19,6 +19,8 @@ package core
 import (
 	"math/big"
 
+	"github.com/ethereum/go-ethereum/core/state"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/consensus/misc/eip4844"
@@ -38,8 +40,9 @@ type ChainContext interface {
 	GetHeader(common.Hash, uint64) *types.Header
 }
 
-// NewEVMBlockContext creates a new context for use in the EVM.
-func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common.Address) vm.BlockContext {
+// NewEVMBlockContext creates a new context for use in the EVM.  If witness is non-nil, the context sources block hashes
+// for the BLOCKHASH opcode from the witness.
+func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common.Address, witness *state.Witness) vm.BlockContext {
 	var (
 		beneficiary common.Address
 		baseFee     *big.Int
@@ -62,10 +65,18 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 	if header.Difficulty.Sign() == 0 {
 		random = &header.MixDigest
 	}
+	var getHash vm.GetHashFunc
+	if witness != nil {
+		getHash = func(n uint64) common.Hash {
+			return witness.BlockHash(n)
+		}
+	} else {
+		getHash = GetHashFn(header, chain)
+	}
 	return vm.BlockContext{
 		CanTransfer: CanTransfer,
 		Transfer:    Transfer,
-		GetHash:     GetHashFn(header, chain),
+		GetHash:     getHash,
 		Coinbase:    beneficiary,
 		BlockNumber: new(big.Int).Set(header.Number),
 		Time:        header.Time,

core/state/database.go

@@ -125,6 +125,10 @@ type Trie interface {
 	// be created with new root and updated trie database for following usage
 	Commit(collectLeaf bool) (common.Hash, *trienode.NodeSet)
 
+	// AccessList returns a map of path->blob containing all trie nodes that have
+	// been accessed.
+	AccessList() map[string][]byte
+
 	// NodeIterator returns an iterator that returns nodes of the trie. Iteration
 	// starts at the key after the given start key. And error will be returned
 	// if fails to create node iterator.

core/state/state_object.go

@@ -323,10 +323,6 @@ func (s *stateObject) finalise() {
 //
 // It assumes all the dirty storage slots have been finalized before.
 func (s *stateObject) updateTrie() (Trie, error) {
-	// Short circuit if nothing changed, don't bother with hashing anything
-	if len(s.uncommittedStorage) == 0 {
-		return s.trie, nil
-	}
 	// Retrieve a pretecher populated trie, or fall back to the database
 	tr := s.getPrefetchedTrie()
 	if tr != nil {
@@ -341,6 +337,14 @@ func (s *stateObject) updateTrie() (Trie, error) {
 			return nil, err
 		}
 	}
+	// Short circuit if nothing changed, don't bother with hashing anything.
+	//
+	// We only quit after the prefetched trie is potentially resolved above
+	// because, when building a stateless witness we will need to collect
+	//storage access witnesses from the object's trie when we commit it.
+	if len(s.uncommittedStorage) == 0 {
+		return s.trie, nil
+	}
 	// Perform trie updates before deletions. This prevents resolution of unnecessary trie nodes
 	// in circumstances similar to the following:
 	//
@@ -446,7 +450,9 @@ func (s *stateObject) commitStorage(op *accountUpdate) {
 //
 // Note, commit may run concurrently across all the state objects. Do not assume
 // thread-safe access to the statedb.
-func (s *stateObject) commit() (*accountUpdate, *trienode.NodeSet, error) {
+func (s *stateObject) commit() (*accountUpdate, *trienode.NodeSet, map[string][]byte, error) {
+	var al map[string][]byte
+
 	// commit the account metadata changes
 	op := &accountUpdate{
 		address: s.address,
@@ -468,12 +474,18 @@ func (s *stateObject) commit() (*accountUpdate, *trienode.NodeSet, error) {
 	if len(op.storages) == 0 {
 		// nothing changed, don't bother to commit the trie
 		s.origin = s.data.Copy()
-		return op, nil, nil
+		if s.trie != nil && !s.trie.IsVerkle() {
+			al = s.trie.AccessList()
+		}
+		return op, nil, al, nil
 	}
 	root, nodes := s.trie.Commit(false)
 	s.data.Root = root
 	s.origin = s.data.Copy()
-	return op, nodes, nil
+	if !s.trie.IsVerkle() {
+		al = s.trie.AccessList()
+	}
+	return op, nodes, al, nil
 }
 
 // AddBalance adds amount to s's balance.