fix issue by outputing proper pubkey format

The way I was outputting the pubkeys would be incorrect if the first byte of
one of the coordinates was 0, since it would print the first non-zero byte
first. The solution was to use the standard openssl function that outputs a
public key to oct.

src/eckey.cc

@@ -435,12 +435,10 @@ Key::AddUncompressed(const Arguments& args)
   EC_KEY *eckey = EC_KEY_new_by_curve_name(NID_secp256k1);
   const EC_GROUP *group = EC_KEY_get0_group(eckey);
 
-
   BN_CTX *ctx;
   EC_POINT *p0, *p1, *r;
   BIGNUM *p0x, *p0y, *p1x, *p1y, *rx, *ry;
   Buffer *rbuf;
-  unsigned char *rcx, *rcy;
 
   p0 = EC_POINT_new(group);
   p1 = EC_POINT_new(group);
@@ -461,19 +459,11 @@ Key::AddUncompressed(const Arguments& args)
   rx = BN_new();
   ry = BN_new();
   EC_POINT_get_affine_coordinates_GFp(group, r, rx, ry, ctx);
-
+  
   rbuf = Buffer::New(65);
-  rcx = (unsigned char *)malloc(32);
-  rcy = (unsigned char *)malloc(32);
-  BN_bn2bin(rx, rcx);
-  BN_bn2bin(ry, rcy);
-  memcpy(&(((unsigned char *)Buffer::Data(rbuf))[1]), rcx, 32);
-  memcpy(&(((unsigned char *)Buffer::Data(rbuf))[33]), rcy, 32);
-  ((unsigned char *)Buffer::Data(rbuf))[0] = 0x04;
+  EC_POINT_point2oct(group, r, POINT_CONVERSION_UNCOMPRESSED, (unsigned char *)Buffer::Data(rbuf), 65, ctx);
 
   //free: eckey, p0, p1, r, p0x, p0y, p1x, p1y, ctx, rx, ry, /*rbuf,*/ rcx, rcy
-  free(rcy); //TODO: also clear
-  free(rcx); //TODO: also clear
   BN_clear_free(ry);
   BN_clear_free(rx);
   //do not free rbuf - this is returned

test/test.Key.js

@@ -1,8 +1,9 @@
 'use strict';
 
+var assert = require('assert');
 var chai = chai || require('chai');
 var bitcore = bitcore || require('../bitcore');
-
+var coinUtil = coinUtil || require('../util/util');
 var buffertools = require('buffertools');
 
 var should = chai.should();
@@ -118,6 +119,7 @@ describe('Key', function() {
     it('should exist', function() {
       should.exist(Key.addUncompressed);
     });
+
     it('should add two uncompressed public keys', function() {
       var key1 = Key.generateSync();
       key1.compressed = false;
@@ -128,6 +130,56 @@ describe('Key', function() {
       var pubkey = Key.addUncompressed(pubkey1, pubkey2);
       pubkey.length.should.equal(65);
     });
+
+    it('a + b should equal b + a', function() {
+      var key1 = Key.generateSync();
+      key1.compressed = false;
+      var key2 = Key.generateSync();
+      key2.compressed = false;
+      var pubkey1 = key1.public;
+      var pubkey2 = key2.public;
+      var r1 = Key.addUncompressed(pubkey1, pubkey2);
+      var r2 = Key.addUncompressed(pubkey2, pubkey1);
+      r1.toString('hex').should.equal(r2.toString('hex'));
+    });
+
+    it('should be able to add these two public keys without error', function() {
+      var key1 = new Key();
+      key1.private = coinUtil.sha256("first " + 3);
+      key1.compressed = false;
+      key1.regenerateSync();
+      var key2 = new Key();
+      key2.private = coinUtil.sha256("second " + 3);
+      key2.compressed = false;
+      key2.regenerateSync();
+      var pubkey1 = key1.public;
+      var pubkey2 = key2.public;
+      var pubkey = Key.addUncompressed(pubkey1, pubkey2);
+      pubkey.length.should.equal(65);
+      var key = new Key();
+      key.public = pubkey;
+      assert(key.public !== null);
+    });
+
+    it('should be able to add many public keys without error', function() {
+      for (var i = 0; i <= 1000; i++) {
+        var key1 = new Key();
+        key1.private = coinUtil.sha256("first " + i);
+        key1.compressed = false;
+        key1.regenerateSync();
+        var key2 = new Key();
+        key2.private = coinUtil.sha256("second " + i);
+        key2.compressed = false;
+        key2.regenerateSync();
+        var pubkey1 = key1.public;
+        var pubkey2 = key2.public;
+        var pubkey = Key.addUncompressed(pubkey1, pubkey2);
+        pubkey.length.should.equal(65);
+        var key = new Key();
+        key.public = pubkey;
+        assert(key.public !== null);
+      };
+    });
   });
 
 });