How to recreate a Bitcoin wallet address from a public key

walletaddress_from_publickey.js

/* 	
	How to recreate a Bitcoin wallet address from a public key 
	Ref: https://github.com/bitcoinjs/bitcoinjs-lib/issues/590
*/

var bitcoin = require('bitcoinjs-lib')
var assert = require('assert')
var bigi = require('bigi')
var crypto = require('crypto')

/* New hash */
var hash = bitcoin.crypto.sha256('correct horse battery staple')

var d = bigi.fromBuffer(hash)

/* Create a new Eleptic Curve key pair from hash */
var keyPair = new bitcoin.ECPair(d)

/* Extract public key buffer(compressed) */
var publicKeyBuffer = keyPair.getPublicKeyBuffer()

/* Copy the (compressed) pub key from the ECPair we have created above */
var publicKey = bitcoin.ECPair.fromPublicKeyBuffer(publicKeyBuffer)

/* Create a new keypair from the copied public key */
var newKeyPair = new bitcoin.ECPair(null, publicKey.Q, { compressed: true })

/* The old address */
console.log(keyPair.getAddress())

/* should be same as the new address */
console.log(newKeyPair.getAddress())