Key should make sure new privkey is less than N

...this involves adding a Curve class, and significant refactoring to make this
possible in a clean way.

bitcore.js

@@ -17,6 +17,7 @@ requireWhenAccessed('buffertools', 'buffertools');
 requireWhenAccessed('Buffers.monkey', './patches/Buffers.monkey');
 requireWhenAccessed('config', './config');
 requireWhenAccessed('const', './const');
+requireWhenAccessed('Curve', './lib/Curve');
 requireWhenAccessed('Deserialize', './lib/Deserialize');
 requireWhenAccessed('log', './util/log');
 requireWhenAccessed('networks', './networks');

browser/build.js

@@ -28,6 +28,7 @@ var modules = [
   'lib/Block',
   'lib/Bloom',
   'lib/Connection',
+  'lib/Curve',
   'lib/Deserialize',
   'lib/Electrum',
   'lib/Message',

lib/BIP32.js

@@ -289,17 +289,20 @@ BIP32.prototype.deriveChild = function(i) {
     var ilGkey = new Key();
     ilGkey.private = il;
     ilGkey.regenerateSync();
-    var ilG = Point.fromKey(ilGkey);
+    ilGkey.compressed = false;
+    var ilG = Point.fromUncompressedPubKey(ilGkey.public);
     var oldkey = new Key();
     oldkey.public = this.eckey.public;
-    var Kpar = Point.fromKey(oldkey);
-    var newpub = Point.add(ilG, Kpar).toKey().public;
+    oldkey.compressed = false;
+    var Kpar = Point.fromUncompressedPubKey(oldkey.public);
+    var newpub = Point.add(ilG, Kpar).toUncompressedPubKey();
 
     ret = new BIP32(null);
     ret.chainCode = new Buffer(ir);
 
     var eckey = new Key();
     eckey.public = newpub; 
+    eckey.compressed = true;
     ret.eckey = eckey;
     ret.hasPrivateKey = false;
   }

lib/Curve.js

@@ -0,0 +1,22 @@
+"use strict";
+var imports = require('soop');
+var bignum = imports.bignum || require('bignum');
+var Point = imports.Point || require('./Point');
+
+var n = bignum.fromBuffer(new Buffer("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141", 'hex'), {size: 32});
+var G = new Point(bignum.fromBuffer(new Buffer("79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798", 'hex'), {size: 32}),
+                  bignum.fromBuffer(new Buffer("483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8", 'hex'), {size: 32}));
+
+/* secp256k1 curve */
+var Curve = function() {
+};
+
+Curve.getG = function() {
+  return G;
+};
+
+Curve.getN = function() {
+  return n;
+};
+
+module.exports = require('soop')(Curve);

lib/Electrum.js

@@ -31,8 +31,9 @@ Electrum.prototype.generatePubKey = function (n, for_change) {
   var sequence_key = new Key();
   sequence_key.private = sequence.toBuffer();
   sequence_key.regenerateSync();
+  sequence_key.compressed = false;
 
-  var sequence_pt = Point.fromKey(sequence_key);
+  var sequence_pt = Point.fromUncompressedPubKey(sequence_key.public);
 
   pt = Point.add(mpk_pt, sequence_pt);
 

lib/browser/Key.js

@@ -1,10 +1,10 @@
 var ECKey = require('../../browser/vendor-bundle.js').ECKey;
-var buffertools = require('buffertools');
 var SecureRandom = require('../SecureRandom');
+var Curve = require('../Curve');
 
 var Key = function() {
   this._pub = null;
-  this.compressed = true; // default
+  this._compressed = true; // default
 };
 
 var bufferToArray = Key.bufferToArray = function(buffer) {
@@ -18,14 +18,13 @@ var bufferToArray = Key.bufferToArray = function(buffer) {
   return ret;
 }
 
-
 Object.defineProperty(Key.prototype, 'public', {
   set: function(p){
     if (!Buffer.isBuffer(p) ) {
       throw new Error('Arg should be a buffer');
     }
     var type = p[0];
-    this.compressed = type!==0x04;
+    this._compressed = type!==0x04;
     this._pub = p;
   },
   get: function(){
@@ -33,8 +32,38 @@ Object.defineProperty(Key.prototype, 'public', {
   }
 });
 
+Object.defineProperty(Key.prototype, 'compressed', {
+  set: function(c) {
+    var oldc = this._compressed;
+    this._compressed = !!c;
+    if (oldc == this._compressed)
+      return;
+    var oldp = this._pub;
+    if (this._pub) {
+      var eckey = new ECKey();
+      eckey.setPub(bufferToArray(this.public));
+      eckey.setCompressed(this._compressed);
+      this._pub = new Buffer(eckey.getPub());
+    }
+    if (!this._compressed) {
+      //bug in eckey
+      //oldp.slice(1).copy(this._pub, 1);
+    }
+  },
+  get: function() {
+    return this._compressed;
+  }
+});
+
 Key.generateSync = function() {
-  var privbuf = SecureRandom.getRandomBuffer(32);
+  var privbuf;
+
+  while(true) {
+    privbuf = SecureRandom.getRandomBuffer(32);
+    if ((bignum.fromBuffer(privbuf, {size: 32})).cmp(Curve.getN()) < 0)
+      break;
+  }
+
   var privhex = privbuf.toString('hex');
   var eck = new ECKey(privhex);
   eck.setCompressed(true);
@@ -42,7 +71,7 @@ Key.generateSync = function() {
 
   ret = new Key();
   ret.private = privbuf;
-  ret.compressed = true;
+  ret._compressed = true;
   ret.public = new Buffer(eck.getPub());
 
   return ret;
@@ -54,8 +83,8 @@ Key.prototype.regenerateSync = function() {
   }
 
   var eck = new ECKey(buffertools.toHex(this.private));
-  eck.setCompressed(this.compressed);
-  this.public = new Buffer(eck.getPub());
+  eck.setCompressed(this._compressed);
+  this._pub = new Buffer(eck.getPub());
   return this;
 };
 
@@ -68,7 +97,7 @@ Key.prototype.signSync = function(hash) {
     throw new Error('Arg should be a 32 bytes hash buffer');
   }
   var eck = new ECKey(buffertools.toHex(this.private));
-  eck.setCompressed(this.compressed);
+  eck.setCompressed(this._compressed);
   var signature = eck.sign(bufferToArray(hash));
   // return it as a buffer to keep c++ compatibility
   return new Buffer(signature);
@@ -98,7 +127,7 @@ Key.prototype.verifySignatureSync = function(hash, sig) {
 
   var eck = new ECKey();
   eck.setPub(bufferToArray(self.public));
-  eck.setCompressed(self.compressed);
+  eck.setCompressed(self._compressed);
   var sigA = bufferToArray(sig);
   var ret = eck.verify(bufferToArray(hash),sigA);
   return ret;

lib/browser/Point.js

@@ -51,31 +51,20 @@ Point.add = function(p1, p2) {
 };
 
 //convert the public key of a Key into a Point
-Point.fromKey = function(key) {
+Point.fromUncompressedPubKey = function(pubkey) {
   var point = new Point();
-  var pubKeyBuf = new Buffer(key.public);
-  var key2 = new ECKey();
-  key2.setCompressed(key.compressed);
-  key2.setPub(Key.bufferToArray(pubKeyBuf));
-  key2.setCompressed(false);
-  point.x = bignum.fromBuffer((new Buffer(key2.getPub())).slice(1, 33), {size: 32});
-  point.y = bignum.fromBuffer((new Buffer(key2.getPub())).slice(33, 65), {size: 32});
+  point.x = bignum.fromBuffer((new Buffer(pubkey)).slice(1, 33), {size: 32});
+  point.y = bignum.fromBuffer((new Buffer(pubkey)).slice(33, 65), {size: 32});
   return point;
 };
 
 //convert the Point into the Key containing a compressed public key
-Point.prototype.toKey = function() {
+Point.prototype.toUncompressedPubKey = function() {
   var xbuf = this.x.toBuffer({size: 32});
   var ybuf = this.y.toBuffer({size: 32});
-  var key = new ECKey();
-  key.setCompressed(false);
   var prefix = new Buffer([0x04]);
-  var pub = Buffer.concat([prefix, xbuf, ybuf]); //this might be wrong
-  key.setPub(Key.bufferToArray(pub));
-  key.setCompressed(true);
-  var key2 = new Key();
-  key2.public = new Buffer(key.getPub());
-  return key2;
+  var pub = Buffer.concat([prefix, xbuf, ybuf]);
+  return pub;
 };
 
 module.exports = require('soop')(Point);

lib/node/Key.js

@@ -1 +1,3 @@
-module.exports = require('bindings')('KeyModule').Key;
+var Key = require('bindings')('KeyModule').Key;
+
+module.exports = Key;

lib/node/Point.js

@@ -1,8 +1,8 @@
 "use strict";
 
 var imports = require('soop').imports();
-var Key = imports.Key || require('../Key'); 
 var bignum = imports.bignum || require('bignum');
+var CPPKey = imports.CPPKey || require('bindings')('KeyModule').Key;
 var assert = require('assert');
 
 //a point on the secp256k1 curve
@@ -13,41 +13,27 @@ var Point = function(x, y) {
 };
 
 Point.add = function(p1, p2) {
-  var key1 = p1.toKey();
-  key1.compressed = false;
-  var key2 = p2.toKey();
-  key2.compressed = false;
-  var pubKey = Key.addUncompressed(key1.public, key2.public);
-  var key = new Key();
-  key.compressed = false;
-  key.public = pubKey;
-  key.compressed = true;
-  return Point.fromKey(key);
+  var u1 = p1.toUncompressedPubKey();
+  var u2 = p2.toUncompressedPubKey();
+  var pubKey = CPPKey.addUncompressed(u1, u2);
+  return Point.fromUncompressedPubKey(pubKey);
 };
 
 //convert the public key of a Key into a Point
-Point.fromKey = function(key) {
+Point.fromUncompressedPubKey = function(pubkey) {
   var point = new Point();
-  var pubKeyBuf = new Buffer(key.public);
-  var key2 = new Key();
-  key2.compressed = key.compressed;
-  key2.public = pubKeyBuf;
-  key2.compressed = false;
-  point.x = bignum.fromBuffer(key2.public.slice(1, 33), {size: 32});
-  point.y = bignum.fromBuffer(key2.public.slice(33, 65), {size: 32});
+  point.x = bignum.fromBuffer(pubkey.slice(1, 33), {size: 32});
+  point.y = bignum.fromBuffer(pubkey.slice(33, 65), {size: 32});
   return point;
 };
 
 //convert the Point into the Key containing a compressed public key
-Point.prototype.toKey = function() {
+Point.prototype.toUncompressedPubKey = function() {
   var xbuf = this.x.toBuffer({size: 32});
   var ybuf = this.y.toBuffer({size: 32});
-  var key = new Key();
-  key.compressed = false;
   var prefix = new Buffer([0x04]);
-  key.public = Buffer.concat([prefix, xbuf, ybuf]); //this might be wrong
-  key.compressed = true;
-  return key;
+  var pubkey = Buffer.concat([prefix, xbuf, ybuf]);
+  return pubkey;
 };
 
 module.exports = require('soop')(Point);

test/index.html

@@ -21,6 +21,7 @@
     <script src="test.Block.js"></script>
     <script src="test.Bloom.js"></script>
     <script src="test.Connection.js"></script>
+    <script src="test.Curve.js"></script>
     <script src="test.EncodedData.js"></script>
     <script src="test.Electrum.js"></script>
     <script src="test.Key.js"></script>

test/test.Curve.js

@@ -0,0 +1,37 @@
+'use strict';
+
+var chai = chai || require('chai');
+var bitcore = bitcore || require('../bitcore');
+var coinUtil = coinUtil || bitcore.util;
+var buffertools = require('buffertools');
+var bignum = require('bignum');
+
+var should = chai.should();
+var assert = chai.assert;
+
+var Curve = bitcore.Curve;
+
+describe('Curve', function() {
+
+  it('should initialize the main object', function() {
+    should.exist(Curve);
+  });
+
+  describe('getN', function() {
+    it('should return a big number', function() {
+      var N = Curve.getN();
+      should.exist(N);
+      N.toBuffer({size: 32}).toString('hex').length.should.equal(64);
+    });
+  });
+
+  describe('getG', function() {
+    it('should return a Point', function() {
+      var G = Curve.getG();
+      should.exist(G.x);
+      G.x.toBuffer({size: 32}).toString('hex').length.should.equal(64);
+      G.y.toBuffer({size: 32}).toString('hex').length.should.equal(64);
+    });
+  });
+
+});

test/test.Key.js

@@ -7,6 +7,9 @@ var should = chai.should();
 var assert = chai.assert;
 
 var Key = bitcore.Key;
+var Point = bitcore.Point;
+var bignum = require('bignum');
+
 describe('Key', function() {
   it('should initialize the main object', function() {
     should.exist(Key);
@@ -15,6 +18,20 @@ describe('Key', function() {
     var k = new Key();
     should.exist(k);
   });
+  it('should set change compressed to uncompressed', function() {
+    var key = Key.generateSync();
+    key.public.length.should.equal(33);
+    key.compressed = false;
+    key.public.length.should.equal(65);
+  });
+  it('should change uncompressed to compressed', function() {
+    var key = Key.generateSync();
+    key.compressed = false;
+    var key2 = new Key();
+    key2.public = key.public;
+    key2.compressed = true;
+    key2.public.length.should.equal(33);
+  });
   it('should be able to generateSync instance', function() {
     var k = Key.generateSync();
     should.exist(k);
@@ -112,4 +129,5 @@ describe('Key', function() {
     var ret= k.verifySignatureSync(a_hash, sig2);
     ret.should.equal(false);
   });
+
 });

test/test.Point.js

@@ -49,8 +49,9 @@ describe('Point', function() {
     var pubKeyBufCompressedHex = "0369b154b42ff9452c31251cb341d7db01ad603dc56d64f9c5fb9e7031b89a241d";
     var key = new Key();
     key.public = new Buffer(pubKeyBufCompressedHex, 'hex');
+    key.compressed = false;
 
-    key.public.toString('hex').should.equal(a.toKey().public.toString('hex'));
+    key.public.toString('hex').should.equal(a.toUncompressedPubKey().toString('hex'));
   });
 
   it('should convert the public key of a Key into a Point', function() {
@@ -60,8 +61,9 @@ describe('Point', function() {
     var pubKeyBufCompressedHex = "0369b154b42ff9452c31251cb341d7db01ad603dc56d64f9c5fb9e7031b89a241d";
     var key = new Key();
     key.public = new Buffer(pubKeyBufCompressedHex, 'hex');
+    key.compressed = false;
 
-    var point = Point.fromKey(key);
+    var point = Point.fromUncompressedPubKey(key.public);
     point.x.toBuffer({size: 32}).toString('hex').should.equal(axhex);
     point.y.toBuffer({size: 32}).toString('hex').should.equal(ayhex);
   });