blockcore-message

Library that helps signing messages in the browser.

About

This is a fork of bitcoinjs-message that adds support for empty message prefix.

This library can be used to easily sign and verify messages that have been signed with Bitcoin-derived keys.

Examples

var bitcoin = require('bitcoinjs-lib') // v4.x.x
var bitcoinMessage = require('bitcoinjs-message')

sign(message, privateKey, compressed[, network.messagePrefix, sigOptions])

• If you pass the sigOptions arg instead of messagePrefix it will dynamically replace.
• sigOptions contains two attributes
  • segwitType should be one of 'p2sh(p2wpkh)' or 'p2wpkh'
  • extraEntropy will be used to create non-deterministic signatures using the RFC6979 extra entropy parameter. R value reuse is not an issue.

Sign a Bitcoin message

var keyPair = bitcoin.ECPair.fromWIF('L4rK1yDtCWekvXuE6oXD9jCYfFNV2cWRpVuPLBcCU2z8TrisoyY1')
var privateKey = keyPair.privateKey
var message = 'This is an example of a signed message.'

var signature = bitcoinMessage.sign(message, privateKey, keyPair.compressed)
console.log(signature.toString('base64'))
// => 'H9L5yLFjti0QTHhPyFrZCT1V/MMnBtXKmoiKDZ78NDBjERki6ZTQZdSMCtkgoNmp17By9ItJr8o7ChX0XxY91nk='

To produce non-deterministic signatures you can pass an extra option to sign()

var { randomBytes } = require('crypto')
var keyPair = bitcoin.ECPair.fromWIF('L4rK1yDtCWekvXuE6oXD9jCYfFNV2cWRpVuPLBcCU2z8TrisoyY1')
var privateKey = keyPair.privateKey
var message = 'This is an example of a signed message.'

var signature = bitcoinMessage.sign(message, privateKey, keyPair.compressed, { extraEntropy: randomBytes(32) })
console.log(signature.toString('base64'))
// => different (but valid) signature each time

Sign a Bitcoin message (with segwit addresses)

// P2SH(P2WPKH) address 'p2sh(p2wpkh)'
var signature = bitcoinMessage.sign(message, privateKey, keyPair.compressed, { segwitType: 'p2sh(p2wpkh)' })
console.log(signature.toString('base64'))
// => 'I9L5yLFjti0QTHhPyFrZCT1V/MMnBtXKmoiKDZ78NDBjERki6ZTQZdSMCtkgoNmp17By9ItJr8o7ChX0XxY91nk='

// P2WPKH address 'p2wpkh'
var signature = bitcoinMessage.sign(message, privateKey, keyPair.compressed, { segwitType: 'p2wpkh' })
console.log(signature.toString('base64'))
// => 'J9L5yLFjti0QTHhPyFrZCT1V/MMnBtXKmoiKDZ78NDBjERki6ZTQZdSMCtkgoNmp17By9ItJr8o7ChX0XxY91nk='

verify(message, address, signature[, network.messagePrefix])

Verify a Bitcoin message

var address = '1F3sAm6ZtwLAUnj7d38pGFxtP3RVEvtsbV'

console.log(bitcoinMessage.verify(message, address, signature))
// => true

LICENSE MIT