coinstring

coinstring is a JavaScript component that is fully compatible with Node.js and the browser. It's used to generate relevant addresses and wallet import formats used by various crypto currencies.

Note: It's an experimental functional replacement for https://github.com/cryptocoinjs/btc-address

Installation

npm install coinstring --save

Usage

There are three functions in this module.

API

coinstring(version, bytes)

Used to convert either a hash160 or private key into an address or wallet import format string respectively.

decode([version], str)

It is the inverse of the coinstring() function i.e. it converts the address or wallet import format into a Buffer of bytes. It throws if the address or wallet import format is not valid. Not valid means that the version doesn't match, or the checksum is incorrect. Returns an object with the follow properites version and bytes.

validate(version, str)

Validates whether the address string or wallet import format string is valid. Returns a true or false.

Common Examples

Convert Private Key to Bitcoin Wallet Import Format

var conv = require('binstring');
var coinstring = require('coinstring');

var privateKeyHex = "1184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd";
var privateKeyHexBuf = conv(privateKeyHex, {in: 'hex', out: 'buffer'});
var version = 0x080; //Bitcoin private key

console.log(coinstring(version, privateKeyHexBuf)); // => 5Hx15HFGyep2CfPxsJKe2fXJsCVn5DEiyoeGGF6JZjGbTRnqfiD

Convert hash160 (aka pubkeyhash) to Bitcoin Address

var conv = require('binstring');
var coinstring = require('coinstring');

var hash160 = "3c176e659bea0f29a3e9bf7880c112b1b31b4dc8"; //hash representing uncompressed
var hash160Buf = conv(hash160, {in: 'hex', out: 'buffer'});
var version = 0x00; //Bitcoin public address

console.log(coinstring(version, hash160Buf)); // => 16UjcYNBG9GTK4uq2f7yYEbuifqCzoLMGS

Convert Private Key to Compressed Bitcoin Wallet Import Format

var conv = require('binstring');
var coinstring = require('coinstring');

var privateKeyHex = "1184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd";

//for compressed, append "01"
privateKeyHex += '01';

var privateKeyHexBuf = conv(privateKeyHex, {in: 'hex', out: 'buffer'});
var version = 0x080; //Bitcoin private key

console.log(coinstring(version, privateKeyHexBuf)); // => KwomKti1X3tYJUUMb1TGSM2mrZk1wb1aHisUNHCQXTZq5auC2qc3

Convert hash160 (aka pubkeyhash) to Dogecoin Address

var conv = require('binstring');
var coinstring = require('coinstring');

var hash160 = "3c176e659bea0f29a3e9bf7880c112b1b31b4dc8"; //hash representing uncompressed
var hash160Buf = conv(hash160, {in: 'hex', out: 'buffer'});
var version = 0x1E; //Dogecoin public address

console.log(coinstring(version, hash160Buf)); // => DAcq9oJpZZAjr56RmF7Y5zmWboZWQ4HAsW

Functional Goodies

coinstring also has some functional goodies. All functions can be partially applied.

Function to Generate Bitcoin Wallet Import Format

var conv = require('binstring');
var coinstring = require('coinstring');

var privateKeyHex = "1184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd";
var privateKeyHexBuf = conv(privateKeyHex, {in: 'hex', out: 'buffer'});
var version = 0x080; //Bitcoin private key

var toBtcWif = coinstring(version)

//later in your program
console.log(toBtcWif(privateKeyHexBuf)); // => 5Hx15HFGyep2CfPxsJKe2fXJsCVn5DEiyoeGGF6JZjGbTRnqfiD

Function to Parse Bitcoin Wallet Import Format

var conv = require('binstring');
var coinstring = require('coinstring');

var wif = "5Hx15HFGyep2CfPxsJKe2fXJsCVn5DEiyoeGGF6JZjGbTRnqfiD";
var version = 0x080; //Bitcoin private key

var fromBtcWif = coinstring.decode(version)

//later in your program
console.log(fromBtcWif(wif).bytes.toString('hex')); // => 51184cd2cdd640ca42cfc3a091c51d549b2f016d454b2774019c2b2d2e08529fd

Function to Validate Bitcoin Testnet Addresses

var conv = require('binstring');
var coinstring = require('coinstring');

var hash160 = "3c176e659bea0f29a3e9bf7880c112b1b31b4dc8"; //hash representing uncompressed
var hash160Buf = conv(hash160, {in: 'hex', out: 'buffer'});
var version = 0x6F; //Bitcoin Testnet Address

var testnetAddressValidator = coinstring.validate(version);

console.log(testnetAddressValidator("mkzgubTA5Ahi6BPSkE6MN9pEafRutznkMe")) // => true

List of Common Crypto Currency Versions

The following is a table of common crypto currency versions. It may seem a bit user unfriendly to have to input the number instead of something like "BTC"; we agree. Another module will be created to address this. In the meantime, use the table below.

Crypto CoinPublic AddressPrivate Wallet Import Format
Bitcoin 0x00 0x80
Bitcoin Script Hash 0x05 N/A
Bitcoin Testnet 0x6E 0xEF
Bitcoin Testnet Script Hash 0xC4 N/A
Dogecoin 0x1E 0x9E
Litecoin 0x30 0xB0
Namecoin 0x34 0xB4

Use in the Browser

Clone the repo:

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

Install Browserify

npm install -g browserify

Nav to repo:

cd coinstring

Install dependencies:

npm install

Run browserify:

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

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

References

License

(MIT License)