From 3a2f51648518c9f632e0bff9d2b8a65dc45ed5cb Mon Sep 17 00:00:00 2001
From: Petar Ivanov <29689712+dartdart26@users.noreply.github.com>
Date: Mon, 30 Oct 2023 18:00:09 +0200
Subject: [PATCH] feat: implement opCreate and opCreate2 in fhevm-go

---
 fhevm/evm.go       | 28 ++++++++++++++++++++++++++++
 fhevm/interface.go |  6 ++++++
 2 files changed, 34 insertions(+)

diff --git a/fhevm/evm.go b/fhevm/evm.go
index 826b17e..db090e6 100644
--- a/fhevm/evm.go
+++ b/fhevm/evm.go
@@ -9,6 +9,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/holiman/uint256"
+	ps "github.com/zama-ai/fhevm-go/crypto"
 )
 
 // A Logger interface for the EVM.
@@ -166,3 +167,30 @@ func padArrayTo32Multiple(input []byte) []byte {
 	}
 	return input
 }
+
+func Create(evm EVMEnvironment, caller common.Address, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
+	contractAddr = crypto.CreateAddress(caller, evm.GetNonce(caller))
+	protectedStorageAddr := ps.CreateProtectedStorageContractAddress(contractAddr)
+	_, _, leftOverGas, err = evm.CreateContract(caller, nil, gas, big.NewInt(0), protectedStorageAddr)
+	if err != nil {
+		ret = nil
+		contractAddr = common.Address{}
+		return
+	}
+	// TODO: consider reverting changes to `protectedStorageAddr` if actual contract creation fails.
+	return evm.CreateContract(caller, code, leftOverGas, value, contractAddr)
+}
+
+func Create2(evm EVMEnvironment, caller common.Address, code []byte, gas uint64, endowment *big.Int, salt *uint256.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
+	codeHash := crypto.Keccak256Hash(code)
+	contractAddr = crypto.CreateAddress2(caller, salt.Bytes32(), codeHash.Bytes())
+	protectedStorageAddr := ps.CreateProtectedStorageContractAddress(contractAddr)
+	_, _, leftOverGas, err = evm.CreateContract2(caller, nil, common.Hash{}, gas, big.NewInt(0), protectedStorageAddr)
+	if err != nil {
+		ret = nil
+		contractAddr = common.Address{}
+		return
+	}
+	// TODO: consider reverting changes to `protectedStorageAddr` if actual contract creation fails.
+	return evm.CreateContract2(caller, code, codeHash, leftOverGas, endowment, contractAddr)
+}
diff --git a/fhevm/interface.go b/fhevm/interface.go
index 2c9a644..ca3f3b4 100644
--- a/fhevm/interface.go
+++ b/fhevm/interface.go
@@ -1,6 +1,8 @@
 package fhevm
 
 import (
+	"math/big"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/holiman/uint256"
 )
@@ -9,6 +11,7 @@ type EVMEnvironment interface {
 	// StateDB related functions
 	GetState(common.Address, common.Hash) common.Hash
 	SetState(common.Address, common.Hash, common.Hash)
+	GetNonce(common.Address) uint64
 
 	// EVM call stack depth
 	GetDepth() int
@@ -21,6 +24,9 @@ type EVMEnvironment interface {
 	IsEthCall() bool
 	IsReadOnly() bool
 
+	CreateContract(caller common.Address, code []byte, gas uint64, value *big.Int, address common.Address) ([]byte, common.Address, uint64, error)
+	CreateContract2(caller common.Address, code []byte, codeHash common.Hash, gas uint64, value *big.Int, address common.Address) ([]byte, common.Address, uint64, error)
+
 	GetFhevmData() *FhevmData
 }