ECPair: stop exposing ECDSA curve

Author: dcousens

src/ecpair.js

@@ -1,25 +1,29 @@
-var bs58check = require('bs58check')
 var bcrypto = require('./crypto')
+var bs58check = require('bs58check')
 var ecdsa = require('./ecdsa')
 var ecurve = require('ecurve')
-var NETWORKS = require('./networks')
 var randomBytes = require('randombytes')
 var typeforce = require('typeforce')
 var types = require('./types')
 
+var NETWORKS = require('./networks')
 var BigInteger = require('bigi')
 
+var secp256k1 = ecurve.getCurveByName('secp256k1')
+
 function ECPair (d, Q, options) {
-  options = options || {}
+  if (options) {
+    typeforce({
+      compressed: types.maybe(types.Boolean),
+      network: types.maybe(types.Network)
+    }, options)
+  }
 
-  typeforce({
-    compressed: types.maybe(types.Boolean),
-    network: types.maybe(types.Network)
-  }, options)
+  options = options || {}
 
   if (d) {
     if (d.signum() <= 0) throw new Error('Private key must be greater than 0')
-    if (d.compareTo(ECPair.curve.n) >= 0) throw new Error('Private key must be less than the curve order')
+    if (d.compareTo(secp256k1.n) >= 0) throw new Error('Private key must be less than the curve order')
     if (Q) throw new TypeError('Unexpected publicKey parameter')
 
     this.d = d
@@ -37,18 +41,15 @@ function ECPair (d, Q, options) {
 Object.defineProperty(ECPair.prototype, 'Q', {
   get: function () {
     if (!this.__Q && this.d) {
-      this.__Q = ECPair.curve.G.multiply(this.d)
+      this.__Q = secp256k1.G.multiply(this.d)
     }
 
     return this.__Q
   }
 })
 
-// Public access to secp256k1 curve
-ECPair.curve = ecurve.getCurveByName('secp256k1')
-
 ECPair.fromPublicKeyBuffer = function (buffer, network) {
-  var Q = ecurve.Point.decodeFrom(ECPair.curve, buffer)
+  var Q = ecurve.Point.decodeFrom(secp256k1, buffer)
 
   return new ECPair(null, Q, {
     compressed: Q.compressed,
@@ -108,7 +109,7 @@ ECPair.makeRandom = function (options) {
   typeforce(types.Buffer256bit, buffer)
 
   var d = BigInteger.fromBuffer(buffer)
-  d = d.mod(ECPair.curve.n)
+  d = d.mod(secp256k1.n)
 
   return new ECPair(d, null, options)
 }
@@ -147,11 +148,11 @@ ECPair.prototype.getPublicKeyBuffer = function () {
 ECPair.prototype.sign = function (hash) {
   if (!this.d) throw new Error('Missing private key')
 
-  return ecdsa.sign(ECPair.curve, hash, this.d)
+  return ecdsa.sign(secp256k1, hash, this.d)
 }
 
 ECPair.prototype.verify = function (hash, signature) {
-  return ecdsa.verify(ECPair.curve, hash, signature, this.Q)
+  return ecdsa.verify(secp256k1, hash, signature, this.Q)
 }
 
 module.exports = ECPair

test/ecpair.js

@@ -11,6 +11,7 @@ var BigInteger = require('bigi')
 var ECPair = require('../src/ecpair')
 
 var fixtures = require('./fixtures/ecpair.json')
+var secp256k1 = ecurve.getCurveByName('secp256k1')
 
 var NETWORKS = require('../src/networks')
 var NETWORKS_LIST = [] // Object.values(NETWORKS)
@@ -53,7 +54,7 @@ describe('ECPair', function () {
 
     it('throws if public and private key given', function () {
       var qBuffer = new Buffer('0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798', 'hex')
-      var Q = ecurve.Point.decodeFrom(ECPair.curve, qBuffer)
+      var Q = ecurve.Point.decodeFrom(secp256k1, qBuffer)
 
       assert.throws(function () {
         new ECPair(BigInteger.ONE, Q)
@@ -200,25 +201,10 @@ describe('ECPair', function () {
       hash = new Buffer(32)
     })
 
-    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 = ECPair.curve[property]
-        var expected = secp256k1[property]
-
-        assert.deepEqual(actual, expected)
-      }
-    })
-
     describe('signing', function () {
       it('wraps ecdsa.sign', sinon.test(function () {
         this.mock(ecdsa).expects('sign')
-          .once().calledWith(ECPair.curve, hash, keyPair.d)
+          .once().calledWith(secp256k1, hash, keyPair.d)
 
         keyPair.sign(hash)
       }))
@@ -241,7 +227,7 @@ describe('ECPair', function () {
 
       it('wraps ecdsa.verify', sinon.test(function () {
         this.mock(ecdsa).expects('verify')
-          .once().calledWith(ECPair.curve, hash, signature, keyPair.Q)
+          .once().calledWith(secp256k1, hash, signature, keyPair.Q)
 
         keyPair.verify(hash, signature)
       }))

test/integration/crypto.js

@@ -7,10 +7,13 @@ var bitcoin = require('../../')
 var blockchain = require('./_blockchain')
 var crypto = require('crypto')
 
+var ecurve = require('ecurve')
+var secp256k1 = ecurve.getCurveByName('secp256k1')
+
 describe('bitcoinjs-lib (crypto)', function () {
   it('can generate a single-key stealth address', function () {
-    var G = bitcoin.ECPair.curve.G
-    var n = bitcoin.ECPair.curve.n
+    var G = secp256k1.G
+    var n = secp256k1.n
 
     function stealthSend (Q) {
       var noncePair = bitcoin.ECPair.makeRandom()
@@ -56,7 +59,7 @@ describe('bitcoinjs-lib (crypto)', function () {
       assert(!master.keyPair.d, 'You already have the parent private key')
       assert(child.keyPair.d, 'Missing child private key')
 
-      var curve = bitcoin.ECPair.curve
+      var curve = secp256k1
       var QP = master.keyPair.Q
       var serQP = master.keyPair.getPublicKeyBuffer()
 
@@ -162,7 +165,7 @@ describe('bitcoinjs-lib (crypto)', function () {
       async.parallel(tasks, function (err) {
         if (err) throw err
 
-        var n = bitcoin.ECPair.curve.n
+        var n = secp256k1.n
 
         for (var i = 0; i < inputs.length; ++i) {
           for (var j = i + 1; j < inputs.length; ++j) {