From 7c945cdc01ae02ca93daca75aadebe46db4254cd Mon Sep 17 00:00:00 2001
From: "Ryan X. Charles" <ryan@bitpay.com>
Date: Fri, 22 Aug 2014 17:43:22 -0700
Subject: [PATCH] add "compressed" feature to pubkeys

...not just privkeys. since, of course, they can be compressed or uncompressed.
---
 lib/address.js       |  6 ++----
 lib/key.js           |  6 +++---
 lib/pubkey.js        | 13 ++++++++++---
 test/test.address.js |  3 ++-
 4 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/lib/address.js b/lib/address.js
index 43be364..608d0b8 100644
--- a/lib/address.js
+++ b/lib/address.js
@@ -11,10 +11,8 @@ function Address(hashbuf, network, type) {
   this.type = type;
 };
 
-Address.prototype.fromPubkey = function(pubkey, network, compressed) {
-  if (typeof compressed === 'undefined')
-    compressed = true;
-  this.hashbuf = Hash.sha256ripemd160(pubkey.toDER(compressed));
+Address.prototype.fromPubkey = function(pubkey, network) {
+  this.hashbuf = Hash.sha256ripemd160(pubkey.toBuffer());
   this.network = network || 'mainnet';
   this.type = 'pubkeyhash';
   return this;
diff --git a/lib/key.js b/lib/key.js
index c48d3f6..a7a3aa5 100644
--- a/lib/key.js
+++ b/lib/key.js
@@ -34,12 +34,12 @@ Key.prototype.fromString = function(str) {
   }
 };
 
-Key.prototype.getAddress = function(network, compressed) {
-  return (new Address()).fromPubkey(this.pubkey, network, compressed);
+Key.prototype.getAddress = function(network) {
+  return Address().fromPubkey(this.pubkey, network);
 };
 
 Key.prototype.privkey2pubkey = function() {
-  this.pubkey = new Pubkey(point.getG().mul(this.privkey.bn));
+  this.pubkey = new Pubkey(point.getG().mul(this.privkey.bn), this.privkey.compressed);
 };
 
 Key.prototype.toString = function() {
diff --git a/lib/pubkey.js b/lib/pubkey.js
index 0c93574..8a659a2 100644
--- a/lib/pubkey.js
+++ b/lib/pubkey.js
@@ -1,12 +1,13 @@
 var Point = require('./point');
 var bn = require('./bn');
 
-var Pubkey = function Pubkey(point) {
+var Pubkey = function Pubkey(point, compressed) {
   if (!(this instanceof Pubkey))
     return new Pubkey(point);
   if (point && !point.getX() && !point.getY())
     throw new Error('Invalid point');
   this.point = point;
+  this.compressed = compressed;
 };
 
 Pubkey.prototype.fromDER = function(buf) {
@@ -18,14 +19,17 @@ Pubkey.prototype.fromDER = function(buf) {
     var x = bn(xbuf);
     var y = bn(ybuf);
     this.point = Point(x, y);
+    this.compressed = false;
   } else if (buf[0] == 0x03) {
     var xbuf = buf.slice(1);
     var x = bn(xbuf);
     this.fromX(true, x);
+    this.compressed = true;
   } else if (buf[0] == 0x02) {
     var xbuf = buf.slice(1);
     var x = bn(xbuf);
     this.fromX(false, x);
+    this.compressed = true;
   } else {
     throw new Error('Invalid DER format pubkey');
   }
@@ -43,10 +47,12 @@ Pubkey.prototype.fromX = function(odd, x) {
 };
 
 Pubkey.prototype.toBuffer = function() {
-  return this.toDER(true);
+  var compressed = typeof this.compressed === 'undefined' ? true : this.compressed;
+  return this.toDER(compressed);
 };
 
 Pubkey.prototype.toDER = function(compressed) {
+  compressed = typeof this.compressed === 'undefined' ? compressed : this.compressed;
   if (typeof compressed !== 'boolean')
     throw new Error('Must specify whether the public key is compressed or not (true or false)');
 
@@ -70,7 +76,8 @@ Pubkey.prototype.toDER = function(compressed) {
 };
 
 Pubkey.prototype.toString = function() {
-  return this.toDER(true).toString('hex');
+  var compressed = typeof this.compressed === 'undefined' ? true : this.compressed;
+  return this.toDER(compressed).toString('hex');
 };
 
 //https://www.iacr.org/archive/pkc2003/25670211/25670211.pdf
diff --git a/test/test.address.js b/test/test.address.js
index d773a13..bdd8c93 100644
--- a/test/test.address.js
+++ b/test/test.address.js
@@ -26,7 +26,8 @@ describe('Address', function() {
       var pubkey = new Pubkey();
       pubkey.fromDER(new Buffer('0285e9737a74c30a873f74df05124f2aa6f53042c2fc0a130d6cbd7d16b944b004', 'hex'));
       var address = new Address();
-      address.fromPubkey(pubkey, 'mainnet', false);
+      pubkey.compressed = false;
+      address.fromPubkey(pubkey, 'mainnet');
       address.toString().should.equal('16JXnhxjJUhxfyx4y6H4sFcxrgt8kQ8ewX');
     });