Ethclient remove ERC777

eth/helpers.go

@@ -1,10 +1,15 @@
 package eth
 
 import (
+	"encoding/hex"
 	"fmt"
+	"math/big"
 	"net/http"
 	"strconv"
 	"strings"
+
+	ethCommon "github.com/ethereum/go-ethereum/common"
+	"golang.org/x/crypto/sha3"
 )
 
 func addBlock(url string) {
@@ -61,3 +66,96 @@ func addTime(seconds float64, url string) {
 		}
 	}()
 }
+
+func createPermitDigest(tokenAddr, owner, spender ethCommon.Address, chainID, value, nonce, deadline *big.Int, tokenName string) ([]byte, error) {
+	abiPermit := []byte("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)")
+	hashPermit := sha3.NewLegacyKeccak256()
+	hashPermit.Write(abiPermit)
+	abiEIP712Domain := []byte("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)")
+	hashEIP712Domain := sha3.NewLegacyKeccak256()
+	hashEIP712Domain.Write(abiEIP712Domain)
+	var encodeBytes []byte
+	paddedHash := ethCommon.LeftPadBytes(hashEIP712Domain.Sum(nil), 32)
+	hashName := sha3.NewLegacyKeccak256()
+	hashName.Write([]byte(tokenName))
+	paddedName := ethCommon.LeftPadBytes(hashName.Sum(nil), 32)
+	hashVersion := sha3.NewLegacyKeccak256()
+	hashVersion.Write([]byte("1"))
+	paddedX := ethCommon.LeftPadBytes(hashVersion.Sum(nil), 32)
+	paddedChainID := ethCommon.LeftPadBytes(chainID.Bytes(), 32)
+	paddedAddr := ethCommon.LeftPadBytes(tokenAddr.Bytes(), 32)
+	encodeBytes = append(encodeBytes, paddedHash...)
+	encodeBytes = append(encodeBytes, paddedName...)
+	encodeBytes = append(encodeBytes, paddedX...)
+	encodeBytes = append(encodeBytes, paddedChainID...)
+	encodeBytes = append(encodeBytes, paddedAddr...)
+	_domainSeparator := sha3.NewLegacyKeccak256()
+	_domainSeparator.Write(encodeBytes)
+
+	var bytes1 []byte
+	paddedHashPermit := ethCommon.LeftPadBytes(hashPermit.Sum(nil), 32)
+	paddedOwner := ethCommon.LeftPadBytes(owner.Bytes(), 32)
+	paddedSpender := ethCommon.LeftPadBytes(spender.Bytes(), 32)
+	paddedValue := ethCommon.LeftPadBytes(value.Bytes(), 32)
+	paddedNonce := ethCommon.LeftPadBytes(nonce.Bytes(), 32)
+	paddedDeadline := ethCommon.LeftPadBytes(deadline.Bytes(), 32)
+	bytes1 = append(bytes1, paddedHashPermit...)
+	bytes1 = append(bytes1, paddedOwner...)
+	bytes1 = append(bytes1, paddedSpender...)
+	bytes1 = append(bytes1, paddedValue...)
+	bytes1 = append(bytes1, paddedNonce...)
+	bytes1 = append(bytes1, paddedDeadline...)
+	hashBytes1 := sha3.NewLegacyKeccak256()
+	hashBytes1.Write(bytes1)
+
+	var bytes2 []byte
+	byte19, err := hex.DecodeString("19")
+	if err != nil {
+		return nil, err
+	}
+	byte01, err := hex.DecodeString("01")
+	if err != nil {
+		return nil, err
+	}
+	paddedY := ethCommon.LeftPadBytes(byte19, 1)
+	paddedZ := ethCommon.LeftPadBytes(byte01, 1)
+	paddedDomainSeparator := ethCommon.LeftPadBytes(_domainSeparator.Sum(nil), 32)
+	paddedHashBytes1 := ethCommon.LeftPadBytes(hashBytes1.Sum(nil), 32)
+	bytes2 = append(bytes2, paddedY...)
+	bytes2 = append(bytes2, paddedZ...)
+	bytes2 = append(bytes2, paddedDomainSeparator...)
+	bytes2 = append(bytes2, paddedHashBytes1...)
+	hashBytes2 := sha3.NewLegacyKeccak256()
+	hashBytes2.Write(bytes2)
+
+	return hashBytes2.Sum(nil), nil
+}
+
+func createPermit(owner, spender ethCommon.Address, amount, deadline *big.Int, digest, signature []byte) []byte {
+	r := signature[0:32]
+	s := signature[32:64]
+	v := signature[64] + byte(27)
+
+	ABIpermit := []byte("permit(address,address,uint256,uint256,uint8,bytes32,bytes32)")
+	hash := sha3.NewLegacyKeccak256()
+	hash.Write(ABIpermit)
+	methodID := hash.Sum(nil)[:4]
+
+	var permit []byte
+	paddedOwner := ethCommon.LeftPadBytes(owner.Bytes(), 32)
+	paddedSpender := ethCommon.LeftPadBytes(spender.Bytes(), 32)
+	paddedAmount := ethCommon.LeftPadBytes(amount.Bytes(), 32)
+	paddedDeadline := ethCommon.LeftPadBytes(deadline.Bytes(), 32)
+	paddedV := ethCommon.LeftPadBytes([]byte{v}, 32)
+
+	permit = append(permit, methodID...)
+	permit = append(permit, paddedOwner...)
+	permit = append(permit, paddedSpender...)
+	permit = append(permit, paddedAmount...)
+	permit = append(permit, paddedDeadline...)
+	permit = append(permit, paddedV...)
+	permit = append(permit, r...)
+	permit = append(permit, s...)
+
+	return permit
+}