ethereumjs-util

What is ethereumjs-util?

The ethereumjs-util package provides a set of utility functions for Ethereum. These utilities include functions for handling addresses, big numbers, hashing, and encoding/decoding data according to the Ethereum protocol standards. It is a foundational package that can be used to develop Ethereum-based applications, facilitating tasks such as transaction formatting, signature verification, and data conversion.

What are ethereumjs-util's main functionalities?

Address Formatting

Converts an Ethereum address to its checksummed version to prevent case sensitivity errors.

const { toChecksumAddress } = require('ethereumjs-util');
const checksumAddress = toChecksumAddress('0xfb6916095ca1df60bb79ce92ce3ea74c37c5d359');
console.log(checksumAddress);

Hashing

Generates a keccak256 hash of the input data, a common hashing function used in Ethereum.

const { keccak256 } = require('ethereumjs-util');
const hash = keccak256(Buffer.from('hello'));
console.log('Hash:', hash.toString('hex'));

Signature Verification

Signs a message hash with a private key and serializes the signature in a format compatible with RPC calls.

const { ecsign, toRpcSig } = require('ethereumjs-util');
const privateKey = Buffer.from('c87509a1c067bbde7aebb4d3c0a0b8ab8bd02b676c91662b5f41c4ec9863d8ee', 'hex');
const msgHash = keccak256(Buffer.from('hello'));
const sig = ecsign(msgHash, privateKey);
const serializedSig = toRpcSig(sig.v, sig.r, sig.s);
console.log('Signature:', serializedSig);

Other packages similar to ethereumjs-util

web3

Web3 is a comprehensive Ethereum library that includes utilities similar to ethereumjs-util but also provides a wide range of functionalities to interact with Ethereum nodes directly. It covers the entire Ethereum API and is more extensive for building DApps.

ethers

Ethers is a lightweight library that aims to be a complete and compact library for interacting with the Ethereum Blockchain and its ecosystem. It includes utilities for addresses, big numbers, and hashing, similar to ethereumjs-util, but also features a complete set of functions to interact with smart contracts and blockchain data.

README

SYNOPSIS

or #ethereumjs on freenode

A collection of utility functions for ethereum. It can be used in node.js or can be in the browser with browserify.

API

./docs/

Most of the string manipulation methods are provided by ethjs-util

LICENSE

MPL-2.0