Pubkey().fromPrivkey()

lib/key.js

@@ -40,7 +40,7 @@ Key.prototype.getAddress = function(networkstr) {
 };
 
 Key.prototype.privkey2pubkey = function() {
-  this.pubkey = new Pubkey({point: point.getG().mul(this.privkey.bn), compressed: this.privkey.compressed});
+  this.pubkey = Pubkey().fromPrivkey(this.privkey);
 };
 
 Key.prototype.toString = function() {

lib/privkey.js

@@ -1,5 +1,5 @@
 var BN = require('./bn');
-var point = require('./point');
+var Point = require('./point');
 var constants = require('./constants');
 var base58check = require('./base58check');
 var Random = require('./random');
@@ -22,14 +22,14 @@ Privkey.prototype.fromRandom = function() {
   do {
     var privbuf = Random.getRandomBuffer(32);
     var bn = BN().fromBuffer(privbuf);
-    var condition = bn.lt(point.getN());
+    var condition = bn.lt(Point.getN());
   } while (!condition);
   this.bn = bn;
   return this;
 };
 
 Privkey.prototype.validate = function() {
-  if (!this.bn.lt(point.getN()))
+  if (!this.bn.lt(Point.getN()))
     throw new Error('Number must be less than N');
   if (typeof constants[this.networkstr] === undefined)
     throw new Error('Must specify the networkstr ("mainnet" or "testnet")');

lib/pubkey.js

@@ -1,5 +1,6 @@
 var Point = require('./point');
 var bn = require('./bn');
+var privkey = require('./privkey');
 
 var Pubkey = function Pubkey(obj) {
   if (!(this instanceof Pubkey))
@@ -16,6 +17,14 @@ Pubkey.prototype.set = function(obj) {
   return this;
 };
 
+Pubkey.prototype.fromPrivkey = function(privkey) {
+  this.set({
+    point: Point.getG().mul(privkey.bn),
+    compressed: privkey.compressed}
+  );
+  return this;
+};
+
 Pubkey.prototype.fromDER = function(buf) {
   if (buf[0] == 0x04) {
     var xbuf = buf.slice(1, 33);

test/test.pubkey.js

@@ -2,6 +2,7 @@ var should = require('chai').should();
 var Pubkey = require('../lib/pubkey');
 var Point = require('../lib/point');
 var Bn = require('../lib/bn');
+var Privkey = require('../lib/privkey');
 
 describe('Pubkey', function() {
   
@@ -24,6 +25,14 @@ describe('Pubkey', function() {
 
   });
 
+  describe('#fromPrivkey', function() {
+    
+    it('should make a public key from a privkey', function() {
+      should.exist(Pubkey().fromPrivkey(Privkey().fromRandom()));
+    });
+
+  });
+
   describe('#fromDER', function() {
     
     it('should parse this uncompressed public key', function() {