eth_bsc_wallet_template

eth_bsc_wallet_template.go

import (
	"context"
	"crypto/ecdsa"
	"crypto/elliptic"
	"encoding/json"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/ethclient"
	"github.com/ethereum/go-ethereum/log"
	"io/ioutil"
	"math/big"
	"math/rand"
	"strconv"
	"sync"
	"time"
)

// hexString without 0x
func toECDSAFromHex(hexString string) *ecdsa.PrivateKey {
	pk := new(ecdsa.PrivateKey)
	pk.D, _ = new(big.Int).SetString(hexString, 16)
	pk.PublicKey.Curve = elliptic.P256()
	pk.PublicKey.X, pk.PublicKey.Y = pk.PublicKey.Curve.ScalarBaseMult(pk.D.Bytes())
	return pk
}

func LoadAccountsFromFile() []Account {
	content, err := ioutil.ReadFile("./_accounts.json") // [{"address":"0x0000000000000","privateKey":"0x0000000000000"}]

	var payload []AccountJson
	err = json.Unmarshal(content, &payload)
	if err != nil {
		log.Error("Error during Unmarshal(): ", err)
		panic(err)
	}

	var res []Account

	for _, o := range payload {
		pkWithout0x := o.PrivateKey[2:]
		pk := toECDSAFromHex(pkWithout0x)
		res = append(res, Account{
			Address:    common.HexToAddress(o.Address),
			PrivateKey: pk,
		})
	}
}

func (a *Manager) GetSignedTx(
	account Account,
	gasPrice *big.Int,
	gasLimit uint64,
	to *common.Address,
	value *big.Int,
	data []byte,
) (signedTx *types.Transaction, err error, duration time.Duration) {
	s := time.Now()

	txTemp := types.NewTx(&types.LegacyTx{
		Nonce:    account.nonce,
		GasPrice: gasPrice,
		Gas:      gasLimit,
		To:       to,
		Value:    value,
		Data:     data,
	})

	signedTx, err = types.SignTx(txTemp, Signer, account.PrivateKey)
	if err != nil {
		return signedTx, err, time.Since(s)
	}

	return signedTx, nil, time.Since(s)
}

// a.client *ethclient.Client
// client, err := ethclient.Dial("ws://127.0.0.1:8546") // стандартный путь к локальной ноде, подходит любой ws/https rpc от сюда https://docs.binance.org/smart-chain/developer/rpc.html
// a.client = client

// get wallet nonce
nonce, err := a.client.NonceAt(context.Background(), account.Address, nil) // lazy nonce (latest mined block nonce+)
nonce, err := a.client.PendingNonceAt(context.Background(), account.Address) // include pending tx nonce+1

err = a.client.SendTransaction(context.Background(), signedTx) // отправить транзакцию

поле Data содержит byte[0] или 0x_назавние_метода_аргумент1_аргумент2 (для аргумента адреса зарезервировано одно количество байт, для uint другое)

название_метода это хеш solidity метода

пример для transfer на solidity:

console.logBytes4(bytes4(keccak256(bytes('transfer(address,uint256)'))));    // 0xa9059cbb = название метода

'transfer(address,uint256)' это хранится в solidity Abi

типичный ERC20/BEP20 abi:

interface IERC20 {
    function balanceOf(address owner) external view returns (uint);
    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// https://bscscan.com/address/0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c#code