nodejs-keccak256

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Node.js Keccak-256

Ethereum uses Keccak-256, not the NIST-standardized SHA3 variant exposed by Node's

crypto.createHash('sha3-256')

以太坊使用的是Keccak-256，而非Node的

crypto.createHash('sha3-256')

提供的NIST标准化SHA3变体。

When to Use

适用场景

Computing Ethereum function selectors or event topics
Building EIP-712, signature, Merkle, or storage-slot helpers in JS/TS
Reviewing any code that hashes Ethereum data with Node crypto directly

计算以太坊函数选择器或事件主题
使用JS/TS构建EIP-712、签名、默克尔树或存储槽相关工具
审查所有直接使用Node crypto模块对以太坊数据进行哈希计算的代码

How It Works

实现原理

The two algorithms produce different outputs for the same input, and Node will not warn you.

javascript

import crypto from 'crypto';
import { keccak256, toUtf8Bytes } from 'ethers';

const data = 'hello';
const nistSha3 = crypto.createHash('sha3-256').update(data).digest('hex');
const keccak = keccak256(toUtf8Bytes(data)).slice(2);

console.log(nistSha3 === keccak); // false

两种算法对相同的输入会产生不同的输出，且Node不会给出任何警告。

javascript

import crypto from 'crypto';
import { keccak256, toUtf8Bytes } from 'ethers';

const data = 'hello';
const nistSha3 = crypto.createHash('sha3-256').update(data).digest('hex');
const keccak = keccak256(toUtf8Bytes(data)).slice(2);

console.log(nistSha3 === keccak); // false

Examples

示例

ethers v6

typescript

import { keccak256, toUtf8Bytes, solidityPackedKeccak256, id } from 'ethers';

const hash = keccak256(new Uint8Array([0x01, 0x02]));
const hash2 = keccak256(toUtf8Bytes('hello'));
const topic = id('Transfer(address,address,uint256)');
const packed = solidityPackedKeccak256(
  ['address', 'uint256'],
  ['0x742d35Cc6634C0532925a3b8D4C9B569890FaC1c', 100n],
);

typescript

import { keccak256, toUtf8Bytes, solidityPackedKeccak256, id } from 'ethers';

const hash = keccak256(new Uint8Array([0x01, 0x02]));
const hash2 = keccak256(toUtf8Bytes('hello'));
const topic = id('Transfer(address,address,uint256)');
const packed = solidityPackedKeccak256(
  ['address', 'uint256'],
  ['0x742d35Cc6634C0532925a3b8D4C9B569890FaC1c', 100n],
);

viem

typescript

import { keccak256, toBytes } from 'viem';

const hash = keccak256(toBytes('hello'));

typescript

import { keccak256, toBytes } from 'viem';

const hash = keccak256(toBytes('hello'));

web3.js

javascript

const hash = web3.utils.keccak256('hello');
const packed = web3.utils.soliditySha3(
  { type: 'address', value: '0x742d35Cc6634C0532925a3b8D4C9B569890FaC1c' },
  { type: 'uint256', value: '100' },
);

javascript

const hash = web3.utils.keccak256('hello');
const packed = web3.utils.soliditySha3(
  { type: 'address', value: '0x742d35Cc6634C0532925a3b8D4C9B569890FaC1c' },
  { type: 'uint256', value: '100' },
);

Common patterns

常用模式

typescript

import { id, keccak256, AbiCoder } from 'ethers';

const selector = id('transfer(address,uint256)').slice(0, 10);
const typeHash = keccak256(toUtf8Bytes('Transfer(address from,address to,uint256 value)'));

function getMappingSlot(key: string, mappingSlot: number): string {
  return keccak256(
    AbiCoder.defaultAbiCoder().encode(['address', 'uint256'], [key, mappingSlot]),
  );
}

typescript

import { id, keccak256, AbiCoder } from 'ethers';

const selector = id('transfer(address,uint256)').slice(0, 10);
const typeHash = keccak256(toUtf8Bytes('Transfer(address from,address to,uint256 value)'));

function getMappingSlot(key: string, mappingSlot: number): string {
  return keccak256(
    AbiCoder.defaultAbiCoder().encode(['address', 'uint256'], [key, mappingSlot]),
  );
}

Address from public key

从公钥生成地址

typescript

import { keccak256 } from 'ethers';

function pubkeyToAddress(pubkeyBytes: Uint8Array): string {
  const hash = keccak256(pubkeyBytes.slice(1));
  return '0x' + hash.slice(-40);
}

typescript

import { keccak256 } from 'ethers';

function pubkeyToAddress(pubkeyBytes: Uint8Array): string {
  const hash = keccak256(pubkeyBytes.slice(1));
  return '0x' + hash.slice(-40);
}

Audit your codebase

审计你的代码库

bash

grep -rn "createHash.*sha3" --include="*.ts" --include="*.js" --exclude-dir=node_modules .
grep -rn "keccak256" --include="*.ts" --include="*.js" . | grep -v node_modules

bash

grep -rn "createHash.*sha3" --include="*.ts" --include="*.js" --exclude-dir=node_modules .
grep -rn "keccak256" --include="*.ts" --include="*.js" . | grep -v node_modules

Rule

规则

For Ethereum contexts, never use

crypto.createHash('sha3-256')

. Use Keccak-aware helpers from

ethers

viem

web3

, or another explicit Keccak implementation.

在以太坊相关开发场景下，切勿使用

crypto.createHash('sha3-256')

。请使用

ethers

、

viem

、

web3

或其他明确实现了Keccak算法的库提供的Keccak相关工具方法。