bitcore/Point.js

139 lines
4.2 KiB
JavaScript

"use strict";
var imports = require('soop').imports();
var Key = imports.Key || require('./Key');
var bignum = imports.bignum || require('bignum');
var assert = require('assert');
//browser
if (!process.versions) {
var ECKey = require('./browser/vendor-bundle.js').ECKey;
var ECPointFp = require('./browser/vendor-bundle.js').ECPointFp;
var ECFieldElementFp = require('./browser/vendor-bundle.js').ECFieldElementFp;
var getSECCurveByName = require('./browser/vendor-bundle.js').getSECCurveByName;
var BigInteger = require('./browser/vendor-bundle.js').BigInteger;
var should = require('chai').should();
}
//a point on the secp256k1 curve
//x and y are bignums
var Point = function(x, y) {
this.x = x;
this.y = y;
};
Point.add = function(p1, p2) {
//node
if (process.versions) {
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);
}
//browser
else {
var ecparams = getSECCurveByName('secp256k1');
var p1xhex = p1.x.toBuffer({size: 32}).toString('hex');
var p1x = new BigInteger(p1xhex, 16);
var p1yhex = p1.y.toBuffer({size: 32}).toString('hex');
var p1y = new BigInteger(p1yhex, 16);
var p1px = new ECFieldElementFp(ecparams.getCurve().getQ(), p1x);
var p1py = new ECFieldElementFp(ecparams.getCurve().getQ(), p1y);
var p1p = new ECPointFp(ecparams.getCurve(), p1px, p1py);
var p2xhex = p2.x.toBuffer({size: 32}).toString('hex');
var p2x = new BigInteger(p2xhex, 16);
var p2yhex = p2.y.toBuffer({size: 32}).toString('hex');
var p2y = new BigInteger(p2yhex, 16);
var p2px = new ECFieldElementFp(ecparams.getCurve().getQ(), p2x);
var p2py = new ECFieldElementFp(ecparams.getCurve().getQ(), p2y);
var p2p = new ECPointFp(ecparams.getCurve(), p2px, p2py);
var p = p1p.add(p2p);
var point = new Point();
var pointxbuf = new Buffer(p.getX().toBigInteger().toByteArrayUnsigned());
point.x = bignum.fromBuffer(pointxbuf, {size: pointxbuf.length});
assert(pointxbuf.length <= 32);
var pointybuf = new Buffer(p.getY().toBigInteger().toByteArrayUnsigned());
assert(pointybuf.length <= 32);
point.y = bignum.fromBuffer(pointybuf, {size: pointybuf.length});
return point;
}
};
//convert the public key of a Key into a Point
Point.fromKey = function(key) {
//node
if (process.versions) {
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});
return point;
}
//browser
else {
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});
return point;
}
};
//convert the Point into the Key containing a compressed public key
Point.prototype.toKey = function() {
//node
if (process.versions) {
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;
}
//browser
else {
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;
}
};
module.exports = require('soop')(Point);