@nomicfoundation/ethereumjs-util

What is @nomicfoundation/ethereumjs-util?

@nomicfoundation/ethereumjs-util is a utility library for Ethereum-related functions. It provides a variety of tools for handling Ethereum addresses, private keys, public keys, signatures, and other cryptographic operations.

What are @nomicfoundation/ethereumjs-util's main functionalities?

Address Generation

This feature allows you to generate an Ethereum address from a private key and convert it to a checksummed address.

const { privateToAddress, toChecksumAddress } = require('@nomicfoundation/ethereumjs-util');
const privateKey = Buffer.from('c87509a1c067bbde78beb793e6fa5e8b8d2a9f1d7b2a9b2a2b2a2b2a2b2a2b2a', 'hex');
const addressBuffer = privateToAddress(privateKey);
const address = toChecksumAddress(addressBuffer.toString('hex'));
console.log(address);

Signature Verification

This feature allows you to sign a message and verify the signature, recovering the public key and address from the signature.

const { ecsign, ecrecover, pubToAddress, toBuffer } = require('@nomicfoundation/ethereumjs-util');
const msg = 'Hello, Ethereum!';
const msgHash = toBuffer('0x' + require('crypto').createHash('sha256').update(msg).digest('hex'));
const privateKey = Buffer.from('c87509a1c067bbde78beb793e6fa5e8b8d2a9f1d7b2a9b2a2b2a2b2a2b2a2b2a', 'hex');
const sig = ecsign(msgHash, privateKey);
const publicKey = ecrecover(msgHash, sig.v, sig.r, sig.s);
const address = pubToAddress(publicKey).toString('hex');
console.log(address);

Hashing

This feature allows you to hash data using the Keccak-256 algorithm, which is used in Ethereum for various purposes.

const { keccak256 } = require('@nomicfoundation/ethereumjs-util');
const data = 'Hello, Ethereum!';
const hash = keccak256(Buffer.from(data));
console.log(hash.toString('hex'));

Other packages similar to @nomicfoundation/ethereumjs-util

ethers

The ethers.js library is a complete and compact library for interacting with the Ethereum blockchain and its ecosystem. It provides similar functionalities for handling addresses, keys, and signatures, but also includes features for interacting with smart contracts and the Ethereum network.

web3

The web3.js library is a comprehensive library for interacting with the Ethereum blockchain. It provides similar utilities for cryptographic operations and address handling, but also includes extensive features for interacting with smart contracts, nodes, and the Ethereum network.

eth-sig-util

The eth-sig-util library provides utilities for signing and verifying Ethereum messages and transactions. It focuses more on signature-related functionalities compared to @nomicfoundation/ethereumjs-util.

README

@ethereumjs/util

A collection of utility functions for Ethereum. It can be used in Node.js and in the browser with browserify.

Installation

To obtain the latest version, simply require the project using npm:

npm install @ethereumjs/util

Usage

import assert from 'assert'
import { isValidChecksumAddress, unpadBuffer } from '@ethereumjs/util'

assert.ok(isValidChecksumAddress('0x2F015C60E0be116B1f0CD534704Db9c92118FB6A'))

assert.ok(unpadBuffer(Buffer.from('000000006600', 'hex')).equals(Buffer.from('6600', 'hex')))

API

Documentation

Read the API docs.

Modules

• account
  • Account class
  • Private/public key and address-related functionality (creation, validation, conversion)
• address
  • Address class and type
• bytes
  • Byte-related helper and conversion functions
• constants
  • Exposed constants
    • e.g. KECCAK256_NULL_S for string representation of Keccak-256 hash of null
• hash
  • This module has been removed with v8, please use ethereum-cryptography directly instead
• signature
  • Signing, signature validation, conversion, recovery
• types
  • Helpful TypeScript types
• internal
  • Internalized helper methods
• withdrawal
  • Withdrawal class (EIP-4895)

BigInt Support

Starting with v8 the usage of BN.js for big numbers has been removed from the library and replaced with the usage of the native JS BigInt data type (introduced in ES2020).

Please note that number-related API signatures have changed along with this version update and the minimal build target has been updated to ES2020.

ethjs-util methods

The following methods are available by an internalized version of the ethjs-util package (MIT license), see internal.ts. The original package is not maintained any more and the original functionality will be replaced by own implementations over time (starting with the v7.1.3 release, October 2021).

• arrayContainsArray
• getBinarySize
• stripHexPrefix
• isHexPrefixed
• isHexString
• padToEven
• fromAscii
• fromUtf8
• toUtf8
• toAscii
• getKeys

They can be imported by name:

import { stripHexPrefix } from '@ethereumjs/util'

EthereumJS

See our organizational documentation for an introduction to EthereumJS as well as information on current standards and best practices. If you want to join for work or carry out improvements on the libraries, please review our contribution guidelines first.

License

MPL-2.0