[golang] go-ethereum으로 이벤트 구독

	go func(client *ethclient.Client) {
		contractAddresses := []common.Address{}
		for _, pair := range Pair {
			contractAddresses = append(contractAddresses, common.HexToAddress(pair.PairAddress))
		}

		SyncEventSig := []byte("Sync(uint112,uint112)")
		hash := sha3.NewLegacyKeccak256()
		hash.Write(SyncEventSig)
		SyncEventHashBytes := hash.Sum(nil)
		signature := common.BytesToHash(SyncEventHashBytes) // 0x1c411e9a96e071241c2f21f7726b17ae89e3cab4c78be50e062b03a9fffbbad1
		topic := []common.Hash{signature}
		topics := [][]common.Hash{topic}
		query := ethereum.FilterQuery{
			Addresses: contractAddresses,
			Topics:    topics,
		}

		logs := make(chan types.Log)
		sub := event.Resubscribe(2*time.Second, func(ctx context.Context) (event.Subscription, error) {
			return client.SubscribeFilterLogs(context.Background(), query, logs)
		})
		defer sub.Unsubscribe()
		for {
			select {
			case err := <-sub.Err():
				log.Fatal("Error on select:", err)
			case vLog := <-logs:
				fmt.Println("Log block number:", vLog.BlockNumber)
				// 여기서 하고 싶은 일 하기.
			}
		}
	}(client)

[Ethereum] 트랜잭션 해시로부터 Public key 및 주소 얻기

Ethereum의 경우 버전에 따라 트랜잭션에 gasPrice를 쓸 지, maxFeePerGas/maxPriorityFeePerGas 를 쓸 지가 정해진다. https://ethereum.stackexchange.com/questions/147692/how-to-get-public-key-by-the-transaction-hash 를 참고.

주소를 얻을 때, Public key에서 앞의 한 바이트(0x04)를 빼고, keccak256을 돌리는 부분에 유의하자.

const { ethers } = require("hardhat");

// 트랜잭션 서명 값
// const r = "0xe680637b83a1dd102364503bd77979b87c92ba651132a4df8e839af69c20af95";
// const s = "0x65becfa32384747adb05f543397baaf23d1c55fa28d0c9a38924912dae6df28f";
// const v = 12266684226873;
// const chainId = 6133342113419;

// 트랜잭션 해시
const txHash = "0xc7159866fb5b94d291e8624bdc731b7a6d46533b398065de7aa7dd1af7b6aa36";
const ethermainHash = "0xef120deb6ff2e516ad44724d220c0cd73166d169a2a0b0f66dfb5613d2d6169c"
const sepoliaHash = "0xfe4ddad4cae9ea353fc91441ee5db6c70bd5468673d907926be92dd4b8a63f63"

// 실제 트랜잭션에 사용된 private key. 아무거나 넣자.
const privateKey = "0x0000000000000000000000000000000000000000000000000000000000000001";

// Web3 프로바이더 설정 (Hardhat 로컬 노드 사용 예시)
const provider = ethers.provider;

// 서명된 트랜잭션 정보 가져오기
async function getPublicKeyFromTransactionHash(provider, txHash) {
  // Fetch the transaction using the transaction hash and provier
  const tx = await provider.getTransaction(txHash);

  console.log(tx);

  // Extract the all the relevant fields from the transaction (We need all of them)
  const unsignedTx = {
    gasPrice: tx.gasPrice,
    gasLimit: tx.gasLimit,
    value: tx.value,
    nonce: tx.nonce,
    data: tx.data,
    chainId: tx.chainId,
    to: tx.to,
    type: tx.type,
    // maxFeePerGas: tx.maxFeePerGas,
    // maxPriorityFeePerGas: tx.maxPriorityFeePerGas,
  };

  // Serializing tx without the signature
  const serializedTx = ethers.utils.serializeTransaction(unsignedTx);

  // Extract the signature (v, r, s) from the transaction
  const { v, r, s } = tx;

  // Join splitted signature
  const signature = ethers.utils.joinSignature({ v, r, s });

  const recoveredPublicKey = ethers.utils.recoverPublicKey(
    ethers.utils.keccak256(serializedTx),
    signature,
  );
  console.log("recoveredPublicKey:", recoveredPublicKey);
  const keccak = ethers.utils.keccak256("0x" + recoveredPublicKey.slice(4))
  console.log("keccak256 of recoveredPublicKey:", keccak, ethers.utils.keccak256("0x" + recoveredPublicKey.slice(4)));

  // Recover the address or public key with (replace recoverAddress by recoverPublicKey) associated with the transaction
  return ethers.utils.recoverAddress(
    ethers.utils.keccak256(serializedTx),
    signature
  );
}

async function main() {
  const address = await getPublicKeyFromTransactionHash(provider, txHash);

  console.log("Address:", address);
}

main()
.then(() => process.exit(0))
.catch((error) => {
    console.error(error);
    process.exit(1);
});

[hardhat/ethers.js] getLedgerSigner

import { subtask } from "hardhat/config";
import { LedgerSigner } from "@ethers-ext/signer-ledger";
import HIDTransport from "@ledgerhq/hw-transport-node-hid";

const USE_LEDGER = {
  "61331819613419": true,
  "2022": true
};

subtask("getLedgerSigner", "Get LedgerSigner")
  .addOptionalPositionalParam("accountNumber", "Account number of the Ledger", "0")
  .setAction(async (taskArgs) => {
    const accountNumber = taskArgs.accountNumber;
    const chainId = (await ethers.provider.getNetwork()).chainId;
    const ledgerNeeded = USE_LEDGER[chainId] ?? false;
    console.log("ChainID:", chainId, "LedgerNeeded:", ledgerNeeded);
    if (ledgerNeeded) {
      const _master = new LedgerSigner(HIDTransport, ethers.provider, `m/44'/60'/${accountNumber}'/0/0`);
      _master.getFeeData = async () => {
        return {
            gasPrice: ethers.BigNumber.from(0),
            lastBaseFeePerGas: ethers.BigNumber.from(0),
            maxFeePerGas: ethers.utils.parseUnits("800", "gwei"),
            maxPriorityFeePerGas: ethers.utils.parseUnits("800", "gwei"),
        };
      };
      console.log(`LedgerSinger: m/44'/60'/${accountNumber}'/0/0:`, await _master.getAddress());
      _master.getBalance = async function() {
        return await this.provider.getBalance(this.getAddress());
      };

      return _master;
    }

    const accounts = await ethers.getSigners();
    return accounts[accountNumber];
  });

사용할 때는 hre를 이용해서 다음과 같이 하면 된다.

import { task } from "hardhat/config";
import './subtasks/getLedgerSigner';

task("ledgerBalance", "Prints an account's balance")
  .addOptionalPositionalParam("accountNumber", "The account number of the ledger", "0")
  .setAction(async (taskArgs) => {
    const signer = await hre.run("getLedgerSigner", { accountNumber: taskArgs.accountNumber });
    console.log("Signer Address:", await signer.getAddress());
    const balance = await signer.getBalance();

    console.log(ethers.utils.formatEther(balance), "ETH");
  });