ecpubkey.js

/* global describe, it, beforeEach */

var assert = require('assert')
var crypto = require('../src/crypto')
var networks = require('../src/networks')

var BigInteger = require('bigi')
var ECPubKey = require('../src/ecpubkey')

var ecurve = require('ecurve')
var curve = ecurve.getCurveByName('secp256k1')

var fixtures = require('./fixtures/ecpubkey.json')

describe('ECPubKey', function () {
  var Q

  beforeEach(function () {
    Q = ecurve.Point.fromAffine(
      curve,
      new BigInteger(fixtures.Q.x),
      new BigInteger(fixtures.Q.y)
    )
  })

  describe('constructor', function () {
    it('defaults to compressed', function () {
      var pubKey = new ECPubKey(Q)

      assert.equal(pubKey.compressed, true)
    })

    it('supports the uncompressed flag', function () {
      var pubKey = new ECPubKey(Q, false)

      assert.equal(pubKey.compressed, false)
    })
  })

  it('uses the secp256k1 curve by default', function () {
    var secp256k1 = ecurve.getCurveByName('secp256k1')

    for (var property in secp256k1) {
      // FIXME: circular structures in ecurve
      if (property === 'G') continue
      if (property === 'infinity') continue

      var actual = ECPubKey.curve[property]
      var expected = secp256k1[property]

      assert.deepEqual(actual, expected)
    }
  })

  describe('fromHex/toHex', function () {
    it('supports compressed points', function () {
      var pubKey = ECPubKey.fromHex(fixtures.compressed.hex)

      assert(pubKey.Q.equals(Q))
      assert.equal(pubKey.toHex(), fixtures.compressed.hex)
      assert.equal(pubKey.compressed, true)
    })

    it('supports uncompressed points', function () {
      var pubKey = ECPubKey.fromHex(fixtures.uncompressed.hex)

      assert(pubKey.Q.equals(Q))
      assert.equal(pubKey.toHex(), fixtures.uncompressed.hex)
      assert.equal(pubKey.compressed, false)
    })
  })

  describe('getAddress', function () {
    it('calculates the expected hash (compressed)', function () {
      var pubKey = new ECPubKey(Q, true)
      var address = pubKey.getAddress()

      assert.equal(address.hash.toString('hex'), fixtures.compressed.hash160)
    })

    it('calculates the expected hash (uncompressed)', function () {
      var pubKey = new ECPubKey(Q, false)
      var address = pubKey.getAddress()

      assert.equal(address.hash.toString('hex'), fixtures.uncompressed.hash160)
    })

    it('supports alternative networks', function () {
      var pubKey = new ECPubKey(Q)
      var address = pubKey.getAddress(networks.testnet)

      assert.equal(address.version, networks.testnet.pubKeyHash)
      assert.equal(address.hash.toString('hex'), fixtures.compressed.hash160)
    })
  })

  describe('verify', function () {
    var pubKey, signature
    beforeEach(function () {
      pubKey = new ECPubKey(Q)

      signature = {
        r: new BigInteger(fixtures.signature.r),
        s: new BigInteger(fixtures.signature.s)
      }
    })

    it('verifies a valid signature', function () {
      var hash = crypto.sha256(fixtures.message)

      assert(pubKey.verify(hash, signature))
    })

    it("doesn't verify the wrong signature", function () {
      var hash = crypto.sha256('mushrooms')

      assert(!pubKey.verify(hash, signature))
    })
  })
})