From 657f992e7b3a473257183b14e9206efa74752bfa Mon Sep 17 00:00:00 2001
From: "Ryan X. Charles" <ryan@bitpay.com>
Date: Wed, 6 Aug 2014 21:02:42 -0700
Subject: [PATCH] point

---
 index.js           |  2 +-
 lib/point.js       | 32 ++++++++++++++++
 test/test.point.js | 92 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 lib/point.js
 create mode 100644 test/test.point.js

diff --git a/index.js b/index.js
index 6a2b336..3eadd93 100644
--- a/index.js
+++ b/index.js
@@ -13,9 +13,9 @@ privsec.base58check = require('./lib/base58check');
 privsec.bn = require('./lib/bn');
 privsec.constants = require('./lib/constants');
 privsec.hash = require('./lib/hash');
+privsec.point = require('./lib/point');
 
 //privsec.key = require('lib/key');
-//privsec.point = require('lib/point');
 //privsec.privkey = require('lib/privkey');
 //privsec.pubkey = require('lib/pubkey');
 //privsec.script = require('lib/script');
diff --git a/lib/point.js b/lib/point.js
new file mode 100644
index 0000000..2275495
--- /dev/null
+++ b/lib/point.js
@@ -0,0 +1,32 @@
+var bn = require('./bn');
+var elliptic = require('elliptic');
+
+var ec = elliptic.curves.secp256k1;
+var Point = ec.curve.point.bind(ec.curve)
+var p = ec.curve.point();
+var Curve = Object.getPrototypeOf(ec.curve);
+Point.prototype = Object.getPrototypeOf(p);
+
+Point.pointFromX = ec.curve.pointFromX.bind(ec.curve);
+
+Point.getG = function() {
+  var p = Point(ec.curve.g.getX(), ec.curve.g.getY());
+  return p;
+};
+
+Point.getN = function() {
+  return bn(ec.curve.n.toArray());
+};
+
+Point.prototype._getX = Point.prototype.getX;
+Point.prototype.getX = function() {
+  var n = bn(this._getX().toArray());
+  return bn(this._getX().toArray());
+};
+
+Point.prototype._getY = Point.prototype.getY;
+Point.prototype.getY = function() {
+  return bn(this._getY().toArray());
+};
+
+module.exports = Point;
diff --git a/test/test.point.js b/test/test.point.js
new file mode 100644
index 0000000..71efd5b
--- /dev/null
+++ b/test/test.point.js
@@ -0,0 +1,92 @@
+var should = require('chai').should();
+var point = require('../lib/point');
+var bn = require('../lib/bn');
+
+describe('point', function() {
+  
+  it('should create a point', function() {
+    var p = point();
+    should.exist(p);
+  });
+
+  describe('#getX', function() {
+    
+    it('should return 0', function() {
+      var p = point();
+      p.getX().toString().should.equal('0');
+    });
+
+    it('should be convertable to a buffer', function() {
+      var p = point();
+      p.getX().toBuffer({size: 32}).length.should.equal(32);
+    });
+
+  });
+
+  describe('#getY', function() {
+    
+    it('should return 0', function() {
+      var p = point();
+      p.getY().toString().should.equal('0');
+    });
+
+    it('should be convertable to a buffer', function() {
+      var p = point();
+      p.getY().toBuffer({size: 32}).length.should.equal(32);
+    });
+
+  });
+
+  describe('#add', function() {
+
+    it('should accurately add g to itself', function() {
+      var p1 = point.getG();
+      var p2 = point.getG();
+      var p3 = p1.add(p2);
+      p3.getX().toString().should.equal('89565891926547004231252920425935692360644145829622209833684329913297188986597');
+      p3.getY().toString().should.equal('12158399299693830322967808612713398636155367887041628176798871954788371653930');
+    });
+
+  });
+
+  describe('#mul', function() {
+
+    it('should accurately multiply g by 2', function() {
+      var g = point.getG();
+      var b = g.mul(bn(2));
+      b.getX().toString().should.equal('89565891926547004231252920425935692360644145829622209833684329913297188986597');
+      b.getY().toString().should.equal('12158399299693830322967808612713398636155367887041628176798871954788371653930');
+    });
+
+    it('should accurately multiply g by n-1', function() {
+      var g = point.getG();
+      var n = point.getN();
+      var b = g.mul(n.sub(1));
+      b.getX().toString().should.equal('55066263022277343669578718895168534326250603453777594175500187360389116729240');
+      b.getY().toString().should.equal('83121579216557378445487899878180864668798711284981320763518679672151497189239');
+    });
+
+    //not sure if this is technically accurate or not...
+    //normally, you should always multiply g by something less than n
+    //but it is the same result in OpenSSL
+    it('should accurately multiply g by n+1', function() {
+      var g = point.getG();
+      var n = point.getN();
+      var b = g.mul(n.add(1));
+      b.getX().toString().should.equal('55066263022277343669578718895168534326250603453777594175500187360389116729240');
+      b.getY().toString().should.equal('32670510020758816978083085130507043184471273380659243275938904335757337482424');
+    });
+
+  });
+
+  describe('#pointFromX', function() {
+    
+    it('should return g', function() {
+      var g = point.getG();
+      var p = point.pointFromX(false, g.getX());
+      g.eq(p).should.equal(true);
+    });
+
+  });
+
+});