core/evm: Random opcode (EIP-4399)

cmd/evm/internal/t8ntool/execution.go

@@ -67,6 +67,7 @@ type ommer struct {
 type stEnv struct {
 	Coinbase         common.Address                      `json:"currentCoinbase"   gencodec:"required"`
 	Difficulty       *big.Int                            `json:"currentDifficulty"`
+	Random           *big.Int                            `json:"currentRandom"`
 	ParentDifficulty *big.Int                            `json:"parentDifficulty"`
 	GasLimit         uint64                              `json:"currentGasLimit"   gencodec:"required"`
 	Number           uint64                              `json:"currentNumber"     gencodec:"required"`
@@ -81,6 +82,7 @@ type stEnv struct {
 type stEnvMarshaling struct {
 	Coinbase         common.UnprefixedAddress
 	Difficulty       *math.HexOrDecimal256
+	Random           *math.HexOrDecimal256
 	ParentDifficulty *math.HexOrDecimal256
 	GasLimit         math.HexOrDecimal64
 	Number           math.HexOrDecimal64

consensus/beacon/consensus.go

@@ -43,7 +43,6 @@ var (
 // error types into the consensus package.
 var (
 	errTooManyUncles    = errors.New("too many uncles")
-	errInvalidMixDigest = errors.New("invalid mix digest")
 	errInvalidNonce     = errors.New("invalid nonce")
 	errInvalidUncleHash = errors.New("invalid uncle hash")
 )
@@ -182,10 +181,7 @@ func (beacon *Beacon) verifyHeader(chain consensus.ChainHeaderReader, header, pa
 	if len(header.Extra) > 32 {
 		return fmt.Errorf("extra-data longer than 32 bytes (%d)", len(header.Extra))
 	}
-	// Verify the seal parts. Ensure the mixhash, nonce and uncle hash are the expected value.
-	if header.MixDigest != (common.Hash{}) {
-		return errInvalidMixDigest
-	}
+	// Verify the seal parts. Ensure the nonce and uncle hash are the expected value.
 	if header.Nonce != beaconNonce {
 		return errInvalidNonce
 	}

core/blockchain.go

@@ -209,6 +209,7 @@ type BlockChain struct {
 	processor  Processor // Block transaction processor interface
 	forker     *ForkChoice
 	vmConfig   vm.Config
+	vmConfigMu *sync.RWMutex
 }
 
 // NewBlockChain returns a fully initialised block chain using information
@@ -245,6 +246,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 		futureBlocks:  futureBlocks,
 		engine:        engine,
 		vmConfig:      vmConfig,
+		vmConfigMu:    &sync.RWMutex{},
 	}
 	bc.forker = NewForkChoice(bc, shouldPreserve)
 	bc.validator = NewBlockValidator(chainConfig, bc, engine)
@@ -1572,6 +1574,9 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 		statedb.StartPrefetcher("chain")
 		activeState = statedb
 
+		bc.vmConfigMu.RLock()
+		vmConfig := bc.vmConfig
+		bc.vmConfigMu.RUnlock()
 		// If we have a followup block, run that against the current state to pre-cache
 		// transactions and probabilistically some of the account/storage trie nodes.
 		var followupInterrupt uint32
@@ -1580,7 +1585,7 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 				throwaway, _ := state.New(parent.Root, bc.stateCache, bc.snaps)
 
 				go func(start time.Time, followup *types.Block, throwaway *state.StateDB, interrupt *uint32) {
-					bc.prefetcher.Prefetch(followup, throwaway, bc.vmConfig, &followupInterrupt)
+					bc.prefetcher.Prefetch(followup, throwaway, vmConfig, &followupInterrupt)
 
 					blockPrefetchExecuteTimer.Update(time.Since(start))
 					if atomic.LoadUint32(interrupt) == 1 {
@@ -1592,7 +1597,7 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 
 		// Process block using the parent state as reference point
 		substart := time.Now()
-		receipts, logs, usedGas, err := bc.processor.Process(block, statedb, bc.vmConfig)
+		receipts, logs, usedGas, err := bc.processor.Process(block, statedb, vmConfig)
 		if err != nil {
 			bc.reportBlock(block, receipts, err)
 			atomic.StoreUint32(&followupInterrupt, 1)

core/blockchain_reader.go

@@ -345,8 +345,17 @@ func (bc *BlockChain) Genesis() *types.Block {
 }
 
 // GetVMConfig returns the block chain VM config.
-func (bc *BlockChain) GetVMConfig() *vm.Config {
-	return &bc.vmConfig
+func (bc *BlockChain) GetVMConfig() vm.Config {
+	bc.vmConfigMu.RLock()
+	defer bc.vmConfigMu.RUnlock()
+	return bc.vmConfig
+}
+
+// SetVMConfig sets the vm config.
+func (bc *BlockChain) SetVMConfig(config vm.Config) {
+	bc.vmConfigMu.Lock()
+	defer bc.vmConfigMu.Unlock()
+	bc.vmConfig = config
 }
 
 // SetTxLookupLimit is responsible for updating the txlookup limit to the

core/evm.go

@@ -61,6 +61,7 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 		Difficulty:  new(big.Int).Set(header.Difficulty),
 		BaseFee:     baseFee,
 		GasLimit:    header.GasLimit,
+		Random:      header.MixDigest,
 	}
 }
 

core/genesis.go

@@ -294,7 +294,7 @@ func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 	if g.GasLimit == 0 {
 		head.GasLimit = params.GenesisGasLimit
 	}
-	if g.Difficulty == nil {
+	if g.Difficulty == nil && g.Mixhash == (common.Hash{}) {
 		head.Difficulty = params.GenesisDifficulty
 	}
 	if g.Config != nil && g.Config.IsLondon(common.Big0) {

core/vm/evm.go

@@ -75,6 +75,7 @@ type BlockContext struct {
 	Time        *big.Int       // Provides information for TIME
 	Difficulty  *big.Int       // Provides information for DIFFICULTY
 	BaseFee     *big.Int       // Provides information for BASEFEE
+	Random      common.Hash    // Provides information for RANDOM
 }
 
 // TxContext provides the EVM with information about a transaction.

core/vm/instructions.go

@@ -477,6 +477,12 @@ func opDifficulty(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext)
 	return nil, nil
 }
 
+func opRandom(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
+	v := new(uint256.Int).SetBytes((interpreter.evm.Context.Random.Bytes()))
+	scope.Stack.push(v)
+	return nil, nil
+}
+
 func opGasLimit(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
 	scope.Stack.push(new(uint256.Int).SetUint64(interpreter.evm.Context.GasLimit))
 	return nil, nil

core/vm/instructions_test.go

@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"math/big"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -654,3 +655,36 @@ func TestCreate2Addreses(t *testing.T) {
 		}
 	}
 }
+
+func TestRandom(t *testing.T) {
+	type testcase struct {
+		name   string
+		random common.Hash
+	}
+
+	for _, tt := range []testcase{
+		{name: "empty hash", random: common.Hash{}},
+		{name: "1", random: common.Hash{0}},
+		{name: "emptyCodeHash", random: emptyCodeHash},
+		{name: "hash(0x010203)", random: crypto.Keccak256Hash([]byte{0x01, 0x02, 0x03})},
+	} {
+		var (
+			env            = NewEVM(BlockContext{Random: tt.random}, TxContext{}, nil, params.TestChainConfig, Config{RandomOpcode: true})
+			stack          = newstack()
+			pc             = uint64(0)
+			evmInterpreter = env.interpreter
+		)
+		opRandom(&pc, evmInterpreter, &ScopeContext{nil, stack, nil})
+		if len(stack.data) != 1 {
+			t.Errorf("Expected one item on stack after %v, got %d: ", tt.name, len(stack.data))
+		}
+		actual := stack.pop()
+		expected, overflow := uint256.FromBig(new(big.Int).SetBytes(tt.random.Bytes()))
+		if overflow {
+			t.Errorf("Testcase %v: invalid overflow", tt.name)
+		}
+		if actual.Cmp(expected) != 0 {
+			t.Errorf("Testcase %v: expected  %x, got %x", tt.name, expected, actual)
+		}
+	}
+}

core/vm/interpreter.go

@@ -29,6 +29,7 @@ type Config struct {
 	Debug                   bool      // Enables debugging
 	Tracer                  EVMLogger // Opcode logger
 	NoBaseFee               bool      // Forces the EIP-1559 baseFee to 0 (needed for 0 price calls)
+	RandomOpcode            bool      // Enables the random opcode
 	EnablePreimageRecording bool      // Enables recording of SHA3/keccak preimages
 
 	JumpTable *JumpTable // EVM instruction table, automatically populated if unset
@@ -69,6 +70,8 @@ func NewEVMInterpreter(evm *EVM, cfg Config) *EVMInterpreter {
 	// If jump table was not initialised we set the default one.
 	if cfg.JumpTable == nil {
 		switch {
+		case cfg.RandomOpcode:
+			cfg.JumpTable = &mergeInstructionSet
 		case evm.chainRules.IsLondon:
 			cfg.JumpTable = &londonInstructionSet
 		case evm.chainRules.IsBerlin:

core/vm/jump_table.go

@@ -54,6 +54,7 @@ var (
 	istanbulInstructionSet         = newIstanbulInstructionSet()
 	berlinInstructionSet           = newBerlinInstructionSet()
 	londonInstructionSet           = newLondonInstructionSet()
+	mergeInstructionSet            = newMergeInstructionSet()
 )
 
 // JumpTable contains the EVM opcodes supported at a given fork.
@@ -77,6 +78,17 @@ func validate(jt JumpTable) JumpTable {
 	return jt
 }
 
+func newMergeInstructionSet() JumpTable {
+	instructionSet := newLondonInstructionSet()
+	instructionSet[RANDOM] = &operation{
+		execute:     opRandom,
+		constantGas: GasQuickStep,
+		minStack:    minStack(0, 1),
+		maxStack:    maxStack(0, 1),
+	}
+	return validate(instructionSet)
+}
+
 // newLondonInstructionSet returns the frontier, homestead, byzantium,
 // contantinople, istanbul, petersburg, berlin and london instructions.
 func newLondonInstructionSet() JumpTable {

core/vm/opcodes.go

@@ -99,6 +99,7 @@ const (
 	CHAINID     OpCode = 0x46
 	SELFBALANCE OpCode = 0x47
 	BASEFEE     OpCode = 0x48
+	RANDOM      OpCode = 0x44 // Same as DIFFICULTY
 )
 
 // 0x50 range - 'storage' and execution.
@@ -275,7 +276,7 @@ var opCodeToString = map[OpCode]string{
 	COINBASE:    "COINBASE",
 	TIMESTAMP:   "TIMESTAMP",
 	NUMBER:      "NUMBER",
-	DIFFICULTY:  "DIFFICULTY",
+	DIFFICULTY:  "DIFFICULTY", // TODO (MariusVanDerWijden) rename to RANDOM post merge
 	GASLIMIT:    "GASLIMIT",
 	CHAINID:     "CHAINID",
 	SELFBALANCE: "SELFBALANCE",

eth/api_backend.go

@@ -204,7 +204,8 @@ func (b *EthAPIBackend) GetTd(ctx context.Context, hash common.Hash) *big.Int {
 func (b *EthAPIBackend) GetEVM(ctx context.Context, msg core.Message, state *state.StateDB, header *types.Header, vmConfig *vm.Config) (*vm.EVM, func() error, error) {
 	vmError := func() error { return nil }
 	if vmConfig == nil {
-		vmConfig = b.eth.blockchain.GetVMConfig()
+		conf := b.eth.blockchain.GetVMConfig()
+		vmConfig = &conf
 	}
 	txContext := core.NewEVMTxContext(msg)
 	context := core.NewEVMBlockContext(header, b.eth.BlockChain(), nil)

eth/catalyst/api.go

@@ -133,7 +133,8 @@ type blockExecutionEnv struct {
 }
 
 func (env *blockExecutionEnv) commitTransaction(tx *types.Transaction, coinbase common.Address) error {
-	vmconfig := *env.chain.GetVMConfig()
+	vmconfig := env.chain.GetVMConfig()
+	vmconfig.RandomOpcode = true
 	snap := env.state.Snapshot()
 	receipt, err := core.ApplyTransaction(env.chain.Config(), env.chain, &coinbase, env.gasPool, env.state, env.header, tx, &env.header.GasUsed, vmconfig)
 	if err != nil {
@@ -276,6 +277,9 @@ func (api *ConsensusAPI) ExecutePayloadV1(params ExecutableDataV1) (ExecutePaylo
 	if td.Cmp(ttd) < 0 {
 		return api.invalid(), fmt.Errorf("can not execute payload on top of block with low td got: %v threshold %v", td, ttd)
 	}
+	conf := api.eth.BlockChain().GetVMConfig()
+	conf.RandomOpcode = true
+	api.eth.BlockChain().SetVMConfig(conf)
 	if err := api.eth.BlockChain().InsertBlockWithoutSetHead(block); err != nil {
 		return api.invalid(), err
 	}
@@ -318,7 +322,11 @@ func (api *ConsensusAPI) assembleBlock(parentHash common.Hash, params *PayloadAt
 		GasLimit:   parent.GasLimit(), // Keep the gas limit constant in this prototype
 		Extra:      []byte{},          // TODO (MariusVanDerWijden) properly set extra data
 		Time:       params.Timestamp,
+		MixDigest:  params.Random,
 	}
+	conf := api.eth.BlockChain().GetVMConfig()
+	conf.RandomOpcode = true
+	api.eth.BlockChain().SetVMConfig(conf)
 	if config := api.eth.BlockChain().Config(); config.IsLondon(header.Number) {
 		header.BaseFee = misc.CalcBaseFee(config, parent.Header())
 	}
@@ -432,7 +440,7 @@ func ExecutableDataToBlock(params ExecutableDataV1) (*types.Block, error) {
 		Time:        params.Timestamp,
 		BaseFee:     params.BaseFeePerGas,
 		Extra:       params.ExtraData,
-		// TODO (MariusVanDerWijden) add params.Random to header once required
+		MixDigest:   params.Random,
 	}
 	block := types.NewBlockWithHeader(header).WithBody(txs, nil /* uncles */)
 	if block.Hash() != params.BlockHash {

miner/worker.go

@@ -773,7 +773,7 @@ func (w *worker) updateSnapshot() {
 func (w *worker) commitTransaction(tx *types.Transaction, coinbase common.Address) ([]*types.Log, error) {
 	snap := w.current.state.Snapshot()
 
-	receipt, err := core.ApplyTransaction(w.chainConfig, w.chain, &coinbase, w.current.gasPool, w.current.state, w.current.header, tx, &w.current.header.GasUsed, *w.chain.GetVMConfig())
+	receipt, err := core.ApplyTransaction(w.chainConfig, w.chain, &coinbase, w.current.gasPool, w.current.state, w.current.header, tx, &w.current.header.GasUsed, w.chain.GetVMConfig())
 	if err != nil {
 		w.current.state.RevertToSnapshot(snap)
 		return nil, err