coinkey

JavaScript component for private keys, public keys, and addresess for crypto currencies such as Bitcoin, Litecoin, and Dogecoin.

Why?

This module provides a convenient way to compute all of the relevant crypto currency details of private keys, public keys, and addresses. It inherits from ECKey and adds the utility of coinstring.

Installation

npm install --save coinkey

Usage

Common Use Cases

Generate a Bunch of Bitcoin Keys/Addresses

var CoinKey = require('coinkey');

var bitcoinAddresses = [];

for (var i = 0; i < 10; ++i) {
  bitcoinAddresses.push(new CoinKey()); //Bitcoin supported by default
}

Generate a Bunch of Namecoin Keys/Addresses

var CoinKey = require('coinkey');
var ci = require('coininfo');

var namecoins = [];
for (var i = 0; i < 10; ++i) {
  namecoins.push(new CoinKey(ci('NMC').versions));
}

Parse a Wallet Import Key and Determine Crypto Currency

var CoinKey = require('coinkey');
var ci = require('coininfo');

var ck = CoinKey.fromWif('QVD3x1RPiWPvyxbTsfxVwaYLyeBZrQvjhZ2aZJUsbuRgsEAGpNQ2');

console.log(ck.privateKey.toString('hex')) // => c4bbcb1fbec99d65bf59d85c8cb62ee2db963f0fe106f483d9afa73bd4e39a8a
console.log(ck.publicAddress) // => DGG6AicS4Qg8Y3UFtcuwJqbuRZ3Q7WtYXv
console.log(ck.compressed) // => true
console.log(ck.versions.public === ci('DOGE').versions.public) // => true

Change to Testnet Later

var CoinKey = require('coinkey');
var ci = require('coininfo');

var ck = new CoinKey(new Buffer('1184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd', 'hex'));
console.log(ck.publicAddress); // => 16UjcYNBG9GTK4uq2f7yYEbuifqCzoLMGS

//change to Testnet
ck.versions = ci('TEST');

console.log(ck.publicAddress); // => mkzgubTA5Ahi6BPSkE6MN9pEafRutznkMe

API

CoinKey([bytes], [compressed], [versions])

Constructor function.

bytes: The private key bytes. Must be 32 bytes in length. Should be an Array, Uint8Array, or a Buffer. If not passed, one will be randomlyl generated.
compressed: Specify whether the key should be compressed or not.
versions: An object that specifies the public and private key versions for addresses and wifs. Defaults to Bitcoin mainnet.

var CoinKey = require('coinkey');
var secureRandom = require('secure-random'); 

var bytes = secureRandom(32); //https://github.com/jprichardson/secure-random
var key1 = new ECKey(bytes);
var key2 = CoinKey(bytes); //<--- can also use without "new"
var compressedKey = new CoinKey(bytes, true);

Properties

privateWif

Get the private WIF (Wallet Import Format).

var CoinKey = require('coinkey');
var conv = require('binstring');

var privateKeyHex = "1184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd";

//Bitcoin WIF
var key = new CoinKey(conv(privateKeyHex, {in: 'hex', out: 'buffer'}), false);
console.log(key.privateWif) // => 5Hx15HFGyep2CfPxsJKe2fXJsCVn5DEiyoeGGF6JZjGbTRnqfiD

//Litecoin WIF
var key = new CoinKey(conv(privateKeyHex, {in: 'hex', out: 'buffer'}), false, {private: 0xB0, public: 0x30});
console.log(key.privateWif) // => 6uFjYQnot5Gtg3HpP87bp4JUpg4FH1gkkV3RyS7LHBbD9Hpt1na

publicKey

Inherited from ECKey. eckey.publicKey

publicAddress

Get the public address.

var CoinKey = require('coinkey');
var conv = require('binstring');

var privateKeyHex = "1184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd";

//Bitcoin Address
var key = new CoinKey(conv(privateKeyHex, {in: 'hex', out: 'buffer'}), false);
console.log(key.publicAddress) // => 16UjcYNBG9GTK4uq2f7yYEbuifqCzoLMGS

//Litecoin Address
var key = new CoinKey(conv(privateKeyHex, {in: 'hex', out: 'buffer'}), false, {private: 0xB0, public: 0x30});
console.log(key.publicAddress) // => 16UjcYNBG9GTK4uq2f7yYEbuifqCzoLMGS

publicHash

Alias: pubKeyHash

Get the public hash i.e. the ripemd160(sha256(publicKey))

var CoinKey = require('coinkey');
var conv = require('binstring');

var privateKeyHex = "1184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd";

var key = new CoinKey(conv(privateKeyHex, {in: 'hex', out: 'buffer'}), false);
console.log(key.publicHash.toString('hex')) // => 3c176e659bea0f29a3e9bf7880c112b1b31b4dc8
console.log(key.publKeyHash.toString('hex')) // => 3c176e659bea0f29a3e9bf7880c112b1b31b4dc8

var keyCompressed = CoinKey(conv(privateKeyHex, {in: 'hex', out: 'buffer'}), true);
console.log(key.publicHash.toString('hex')) // => a1c2f92a9dacbd2991c3897724a93f338e44bdc1
console.log(key.publKeyHash.toString('hex')) // => a1c2f92a9dacbd2991c3897724a93f338e44bdc1

publicPoint

Inherited from ECKey. eckey.publicPoint

toString()

Returns the string representation of the private key.

Methods

fromWif(wif, [versions])

Class method to create a CoinKey from a wif.

var ck = CoinKey.fromWif('KwomKti1X3tYJUUMb1TGSM2mrZk1wb1aHisUNHCQXTZq5auC2qc3');
console.log(ck.compressed); // => true
console.log(ck.privateKey.toString('hex')) // => 1184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd
console.log(ck.publicAddress); // => 1FkKMsKNJqWSDvTvETqcCeHcUQQ64kSC6s

Browser Support

Clone the repo:

git clone https://github.com/cryptocoinjs/coinkey

Install Browserify

npm install -g browserify

Nav to repo:

cd coinkey

Install dependencies:

npm install

Run browserify:

browserify --standalone coinkey < lib/coinkey.js > lib/coinkey.bundle.js

You can now drop coinkey.bundle.js in a <script> tag.

References

http://procbits.com/2013/08/27/generating-a-bitcoin-address-with-javascript
https://github.com/bitcoinjs/bitcoinjs-lib/blob/master/src/eckey.js
https://github.com/vbuterin/bitcoinjs-lib/blob/master/src/eckey.js