feat(vm): EVM active precompiles (backport ethereum#7) (ethereum#16)

Co-authored-by: Federico Kunze Küllmer <[email protected]>
Co-authored-by: Freddy Caceres <[email protected]>
Co-authored-by: Vladislav Varadinov <[email protected]>

CHANGELOG.md

@@ -39,6 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* [#7](https://github.com/evmos/go-ethereum/pull/7) Implement custom active precompiles for the EVM.
 * [#6](https://github.com/evmos/go-ethereum/pull/6) Refactor `Stack` implementation
 * [#3](https://github.com/evmos/go-ethereum/pull/3) Move the `JumpTable` defaults to a separate function.
 * [#2](https://github.com/evmos/go-ethereum/pull/2) Define `Interpreter` interface for the EVM.

core/state_transition.go

@@ -42,8 +42,10 @@ The state transitioning model does all the necessary work to work out a valid ne
 3) Create a new state object if the recipient is \0*32
 4) Value transfer
 == If contract creation ==
-  4a) Attempt to run transaction data
-  4b) If valid, use result as code for the new state object
+
+	4a) Attempt to run transaction data
+	4b) If valid, use result as code for the new state object
+
 == end ==
 5) Run Script section
 6) Derive new state root
@@ -262,13 +264,13 @@ func (st *StateTransition) preCheck() error {
 // TransitionDb will transition the state by applying the current message and
 // returning the evm execution result with following fields.
 //
-// - used gas:
-//      total gas used (including gas being refunded)
-// - returndata:
-//      the returned data from evm
-// - concrete execution error:
-//      various **EVM** error which aborts the execution,
-//      e.g. ErrOutOfGas, ErrExecutionReverted
+//   - used gas:
+//     total gas used (including gas being refunded)
+//   - returndata:
+//     the returned data from evm
+//   - concrete execution error:
+//     various **EVM** error which aborts the execution,
+//     e.g. ErrOutOfGas, ErrExecutionReverted
 //
 // However if any consensus issue encountered, return the error directly with
 // nil evm execution result.
@@ -319,8 +321,9 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 
 	// Set up the initial access list.
 	if rules.IsBerlin {
-		st.state.PrepareAccessList(msg.From(), msg.To(), vm.ActivePrecompiles(rules), msg.AccessList())
+		st.state.PrepareAccessList(msg.From(), msg.To(), st.evm.ActivePrecompiles(rules), msg.AccessList())
 	}
+
 	var (
 		ret   []byte
 		vmerr error // vm errors do not effect consensus and are therefore not assigned to err

core/vm/contracts.go

@@ -17,9 +17,11 @@
 package vm
 
 import (
+	"bytes"
 	"crypto/sha256"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -126,8 +128,8 @@ func init() {
 	}
 }
 
-// ActivePrecompiles returns the precompiles enabled with the current configuration.
-func ActivePrecompiles(rules params.Rules) []common.Address {
+// DefaultActivePrecompiles returns the set of precompiles enabled with the default configuration.
+func DefaultActivePrecompiles(rules params.Rules) []common.Address {
 	switch {
 	case rules.IsBerlin:
 		return PrecompiledAddressesBerlin
@@ -140,6 +142,87 @@ func ActivePrecompiles(rules params.Rules) []common.Address {
 	}
 }
 
+// DefaultPrecompiles define the mapping of address and precompiles from the default configuration
+func DefaultPrecompiles(rules params.Rules) (precompiles map[common.Address]PrecompiledContract) {
+	switch {
+	case rules.IsBerlin:
+		precompiles = PrecompiledContractsBerlin
+	case rules.IsIstanbul:
+		precompiles = PrecompiledContractsIstanbul
+	case rules.IsByzantium:
+		precompiles = PrecompiledContractsByzantium
+	default:
+		precompiles = PrecompiledContractsHomestead
+	}
+
+	return precompiles
+}
+
+// ActivePrecompiles returns the precompiles enabled with the current configuration.
+//
+// NOTE: The rules argument is ignored as the active precompiles can be set via the WithPrecompiles
+// method according to the chain rules from the current block context.
+func (evm *EVM) ActivePrecompiles(_ params.Rules) []common.Address {
+	return evm.activePrecompiles
+}
+
+// Precompile returns a precompiled contract for the given address. This
+// function returns false if the address is not a registered precompile.
+func (evm *EVM) Precompile(addr common.Address) (PrecompiledContract, bool) {
+	p, ok := evm.precompiles[addr]
+	return p, ok
+}
+
+// WithPrecompiles sets the precompiled contracts and the slice of actives precompiles.
+// IMPORTANT: This function does NOT validate the precompiles provided to the EVM. The caller should
+// use the ValidatePrecompiles function for this purpose prior to calling WithPrecompiles.
+func (evm *EVM) WithPrecompiles(
+	precompiles map[common.Address]PrecompiledContract,
+	activePrecompiles []common.Address,
+) {
+	evm.precompiles = precompiles
+	evm.activePrecompiles = activePrecompiles
+}
+
+// ValidatePrecompiles validates the precompile map against the active
+// precompile slice.
+// It returns an error if the precompiled contract map has a different length
+// than the slice of active contract addresses. This function also checks for
+// duplicates, invalid addresses and empty precompile contract instances.
+func ValidatePrecompiles(
+	precompiles map[common.Address]PrecompiledContract,
+	activePrecompiles []common.Address,
+) error {
+	if len(precompiles) != len(activePrecompiles) {
+		return fmt.Errorf("precompiles length mismatch (expected %d, got %d)", len(precompiles), len(activePrecompiles))
+	}
+
+	dupActivePrecompiles := make(map[common.Address]bool)
+
+	for _, addr := range activePrecompiles {
+		if dupActivePrecompiles[addr] {
+			return fmt.Errorf("duplicate active precompile: %s", addr)
+		}
+
+		precompile, ok := precompiles[addr]
+		if !ok {
+			return fmt.Errorf("active precompile address doesn't exist in precompiles map: %s", addr)
+		}
+
+		if precompile == nil {
+			return fmt.Errorf("precompile contract cannot be nil: %s", addr)
+		}
+
+		if bytes.Equal(addr.Bytes(), common.Address{}.Bytes()) {
+			return fmt.Errorf("precompile cannot be the zero address: %s", addr)
+		}
+
+		dupActivePrecompiles[addr] = true
+	}
+
+	return nil
+}
+
 // RunPrecompiledContract runs and evaluates the output of a precompiled contract.
 // It returns
 // - the returned bytes,
@@ -203,6 +286,7 @@ type sha256hash struct{}
 func (c *sha256hash) RequiredGas(input []byte) uint64 {
 	return uint64(len(input)+31)/32*params.Sha256PerWordGas + params.Sha256BaseGas
 }
+
 func (c *sha256hash) Run(input []byte) ([]byte, error) {
 	h := sha256.Sum256(input)
 	return h[:], nil
@@ -218,6 +302,7 @@ type ripemd160hash struct{}
 func (c *ripemd160hash) RequiredGas(input []byte) uint64 {
 	return uint64(len(input)+31)/32*params.Ripemd160PerWordGas + params.Ripemd160BaseGas
 }
+
 func (c *ripemd160hash) Run(input []byte) ([]byte, error) {
 	ripemd := ripemd160.New()
 	ripemd.Write(input)
@@ -234,6 +319,7 @@ type dataCopy struct{}
 func (c *dataCopy) RequiredGas(input []byte) uint64 {
 	return uint64(len(input)+31)/32*params.IdentityPerWordGas + params.IdentityBaseGas
 }
+
 func (c *dataCopy) Run(in []byte) ([]byte, error) {
 	return in, nil
 }
@@ -264,9 +350,10 @@ var (
 // modexpMultComplexity implements bigModexp multComplexity formula, as defined in EIP-198
 //
 // def mult_complexity(x):
-//    if x <= 64: return x ** 2
-//    elif x <= 1024: return x ** 2 // 4 + 96 * x - 3072
-//    else: return x ** 2 // 16 + 480 * x - 199680
+//
+//	if x <= 64: return x ** 2
+//	elif x <= 1024: return x ** 2 // 4 + 96 * x - 3072
+//	else: return x ** 2 // 16 + 480 * x - 199680
 //
 // where is x is max(length_of_MODULUS, length_of_BASE)
 func modexpMultComplexity(x *big.Int) *big.Int {

core/vm/evm.go

@@ -41,22 +41,6 @@ type (
 	GetHashFunc func(uint64) common.Hash
 )
 
-func (evm *EVM) precompile(addr common.Address) (PrecompiledContract, bool) {
-	var precompiles map[common.Address]PrecompiledContract
-	switch {
-	case evm.chainRules.IsBerlin:
-		precompiles = PrecompiledContractsBerlin
-	case evm.chainRules.IsIstanbul:
-		precompiles = PrecompiledContractsIstanbul
-	case evm.chainRules.IsByzantium:
-		precompiles = PrecompiledContractsByzantium
-	default:
-		precompiles = PrecompiledContractsHomestead
-	}
-	p, ok := precompiles[addr]
-	return p, ok
-}
-
 // BlockContext provides the EVM with auxiliary information. Once provided
 // it shouldn't be modified.
 type BlockContext struct {
@@ -121,6 +105,10 @@ type EVM struct {
 	// available gas is calculated in gasCall* according to the 63/64 rule and later
 	// applied in opCall*.
 	callGasTemp uint64
+	// precompiles defines the precompiled contracts used by the EVM
+	precompiles map[common.Address]PrecompiledContract
+	// activePrecompiles defines the precompiles that are currently active
+	activePrecompiles []common.Address
 }
 
 // NewEVM returns a new EVM. The returned EVM is not thread safe and should
@@ -134,8 +122,11 @@ func NewEVM(blockCtx BlockContext, txCtx TxContext, statedb StateDB, chainConfig
 		chainConfig: chainConfig,
 		chainRules:  chainConfig.Rules(blockCtx.BlockNumber, blockCtx.Random != nil),
 	}
-
+	// set the default precompiles
+	evm.activePrecompiles = DefaultActivePrecompiles(evm.chainRules)
+	evm.precompiles = DefaultPrecompiles(evm.chainRules)
 	evm.interpreter = NewEVMInterpreter(evm, config)
+
 	return evm
 }
 
@@ -181,7 +172,7 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 		return nil, gas, ErrInsufficientBalance
 	}
 	snapshot := evm.StateDB.Snapshot()
-	p, isPrecompile := evm.precompile(addr)
+	p, isPrecompile := evm.Precompile(addr)
 
 	if !evm.StateDB.Exist(addr) {
 		if !isPrecompile && evm.chainRules.IsEIP158 && value.Sign() == 0 {
@@ -280,7 +271,7 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
 	}
 
 	// It is allowed to call precompiles, even via delegatecall
-	if p, isPrecompile := evm.precompile(addr); isPrecompile {
+	if p, isPrecompile := evm.Precompile(addr); isPrecompile {
 		ret, gas, err = RunPrecompiledContract(p, input, gas)
 	} else {
 		addrCopy := addr
@@ -321,7 +312,7 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
 	}
 
 	// It is allowed to call precompiles, even via delegatecall
-	if p, isPrecompile := evm.precompile(addr); isPrecompile {
+	if p, isPrecompile := evm.Precompile(addr); isPrecompile {
 		ret, gas, err = RunPrecompiledContract(p, input, gas)
 	} else {
 		addrCopy := addr
@@ -370,7 +361,7 @@ func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte
 		}(gas)
 	}
 
-	if p, isPrecompile := evm.precompile(addr); isPrecompile {
+	if p, isPrecompile := evm.Precompile(addr); isPrecompile {
 		ret, gas, err = RunPrecompiledContract(p, input, gas)
 	} else {
 		// At this point, we use a copy of address. If we don't, the go compiler will

core/vm/runtime/runtime.go

@@ -119,8 +119,9 @@ func Execute(code, input []byte, cfg *Config) ([]byte, *state.StateDB, error) {
 		sender  = vm.AccountRef(cfg.Origin)
 	)
 	if rules := cfg.ChainConfig.Rules(vmenv.Context.BlockNumber, vmenv.Context.Random != nil); rules.IsBerlin {
-		cfg.State.PrepareAccessList(cfg.Origin, &address, vm.ActivePrecompiles(rules), nil)
+		cfg.State.PrepareAccessList(cfg.Origin, &address, vm.DefaultActivePrecompiles(rules), nil)
 	}
+
 	cfg.State.CreateAccount(address)
 	// set the receiver's (the executing contract) code for execution.
 	cfg.State.SetCode(address, code)
@@ -151,8 +152,9 @@ func Create(input []byte, cfg *Config) ([]byte, common.Address, uint64, error) {
 		sender = vm.AccountRef(cfg.Origin)
 	)
 	if rules := cfg.ChainConfig.Rules(vmenv.Context.BlockNumber, vmenv.Context.Random != nil); rules.IsBerlin {
-		cfg.State.PrepareAccessList(cfg.Origin, nil, vm.ActivePrecompiles(rules), nil)
+		cfg.State.PrepareAccessList(cfg.Origin, nil, vm.DefaultActivePrecompiles(rules), nil)
 	}
+
 	// Call the code with the given configuration.
 	code, address, leftOverGas, err := vmenv.Create(
 		sender,
@@ -177,7 +179,7 @@ func Call(address common.Address, input []byte, cfg *Config) ([]byte, uint64, er
 	statedb := cfg.State
 
 	if rules := cfg.ChainConfig.Rules(vmenv.Context.BlockNumber, vmenv.Context.Random != nil); rules.IsBerlin {
-		statedb.PrepareAccessList(cfg.Origin, &address, vm.ActivePrecompiles(rules), nil)
+		statedb.PrepareAccessList(cfg.Origin, &address, vm.DefaultActivePrecompiles(rules), nil)
 	}
 	// Call the code with the given configuration.
 	ret, leftOverGas, err := vmenv.Call(

eth/tracers/js/goja.go

@@ -49,9 +49,11 @@ func init() {
 // hex strings into big ints.
 var bigIntProgram = goja.MustCompile("bigInt", bigIntegerJS, false)
 
-type toBigFn = func(vm *goja.Runtime, val string) (goja.Value, error)
-type toBufFn = func(vm *goja.Runtime, val []byte) (goja.Value, error)
-type fromBufFn = func(vm *goja.Runtime, buf goja.Value, allowString bool) ([]byte, error)
+type (
+	toBigFn   = func(vm *goja.Runtime, val string) (goja.Value, error)
+	toBufFn   = func(vm *goja.Runtime, val []byte) (goja.Value, error)
+	fromBufFn = func(vm *goja.Runtime, buf goja.Value, allowString bool) ([]byte, error)
+)
 
 func toBuf(vm *goja.Runtime, bufType goja.Value, val []byte) (goja.Value, error) {
 	// bufType is usually Uint8Array. This is equivalent to `new Uint8Array(val)` in JS.
@@ -238,7 +240,7 @@ func (t *jsTracer) CaptureStart(env *vm.EVM, from common.Address, to common.Addr
 	t.ctx["block"] = t.vm.ToValue(env.Context.BlockNumber.Uint64())
 	// Update list of precompiles based on current block
 	rules := env.ChainConfig().Rules(env.Context.BlockNumber, env.Context.Random != nil)
-	t.activePrecompiles = vm.ActivePrecompiles(rules)
+	t.activePrecompiles = env.ActivePrecompiles(rules)
 	t.ctx["intrinsicGas"] = t.vm.ToValue(t.gasLimit - gas)
 }
 

eth/tracers/native/4byte.go

@@ -37,14 +37,15 @@ func init() {
 // a reversed signature can be matched against the size of the data.
 //
 // Example:
-//   > debug.traceTransaction( "0x214e597e35da083692f5386141e69f47e973b2c56e7a8073b1ea08fd7571e9de", {tracer: "4byteTracer"})
-//   {
-//     0x27dc297e-128: 1,
-//     0x38cc4831-0: 2,
-//     0x524f3889-96: 1,
-//     0xadf59f99-288: 1,
-//     0xc281d19e-0: 1
-//   }
+//
+//	> debug.traceTransaction( "0x214e597e35da083692f5386141e69f47e973b2c56e7a8073b1ea08fd7571e9de", {tracer: "4byteTracer"})
+//	{
+//	  0x27dc297e-128: 1,
+//	  0x38cc4831-0: 2,
+//	  0x524f3889-96: 1,
+//	  0xadf59f99-288: 1,
+//	  0xc281d19e-0: 1
+//	}
 type fourByteTracer struct {
 	env               *vm.EVM
 	ids               map[string]int   // ids aggregates the 4byte ids found
@@ -84,7 +85,7 @@ func (t *fourByteTracer) CaptureStart(env *vm.EVM, from common.Address, to commo
 
 	// Update list of precompiles based on current block
 	rules := env.ChainConfig().Rules(env.Context.BlockNumber, env.Context.Random != nil)
-	t.activePrecompiles = vm.ActivePrecompiles(rules)
+	t.activePrecompiles = env.ActivePrecompiles(rules)
 
 	// Save the outer calldata also
 	if len(input) >= 4 {