71 lines
2.6 KiB
JavaScript
71 lines
2.6 KiB
JavaScript
"use strict";
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var imports = require('soop').imports();
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var Key = imports.Key || require('./Key');
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var bignum = imports.bignum || require('bignum');
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var assert = require('assert');
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var ECKey = require('../../browser/vendor-bundle.js').ECKey;
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var ECPointFp = require('../../browser/vendor-bundle.js').ECPointFp;
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var ECFieldElementFp = require('../../browser/vendor-bundle.js').ECFieldElementFp;
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var getSECCurveByName = require('../../browser/vendor-bundle.js').getSECCurveByName;
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var BigInteger = require('../../browser/vendor-bundle.js').BigInteger;
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var should = require('chai').should();
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//a point on the secp256k1 curve
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//x and y are bignums
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var Point = function(x, y) {
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this.x = x;
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this.y = y;
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};
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Point.add = function(p1, p2) {
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var ecparams = getSECCurveByName('secp256k1');
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var p1xhex = p1.x.toBuffer({size: 32}).toString('hex');
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var p1x = new BigInteger(p1xhex, 16);
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var p1yhex = p1.y.toBuffer({size: 32}).toString('hex');
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var p1y = new BigInteger(p1yhex, 16);
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var p1px = new ECFieldElementFp(ecparams.getCurve().getQ(), p1x);
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var p1py = new ECFieldElementFp(ecparams.getCurve().getQ(), p1y);
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var p1p = new ECPointFp(ecparams.getCurve(), p1px, p1py);
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var p2xhex = p2.x.toBuffer({size: 32}).toString('hex');
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var p2x = new BigInteger(p2xhex, 16);
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var p2yhex = p2.y.toBuffer({size: 32}).toString('hex');
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var p2y = new BigInteger(p2yhex, 16);
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var p2px = new ECFieldElementFp(ecparams.getCurve().getQ(), p2x);
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var p2py = new ECFieldElementFp(ecparams.getCurve().getQ(), p2y);
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var p2p = new ECPointFp(ecparams.getCurve(), p2px, p2py);
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var p = p1p.add(p2p);
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var point = new Point();
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var pointxbuf = new Buffer(p.getX().toBigInteger().toByteArrayUnsigned());
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point.x = bignum.fromBuffer(pointxbuf, {size: pointxbuf.length});
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assert(pointxbuf.length <= 32);
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var pointybuf = new Buffer(p.getY().toBigInteger().toByteArrayUnsigned());
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assert(pointybuf.length <= 32);
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point.y = bignum.fromBuffer(pointybuf, {size: pointybuf.length});
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return point;
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};
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//convert the public key of a Key into a Point
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Point.fromUncompressedPubKey = function(pubkey) {
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var point = new Point();
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point.x = bignum.fromBuffer((new Buffer(pubkey)).slice(1, 33), {size: 32});
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point.y = bignum.fromBuffer((new Buffer(pubkey)).slice(33, 65), {size: 32});
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return point;
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};
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//convert the Point into the Key containing a compressed public key
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Point.prototype.toUncompressedPubKey = function() {
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var xbuf = this.x.toBuffer({size: 32});
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var ybuf = this.y.toBuffer({size: 32});
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var prefix = new Buffer([0x04]);
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var pub = Buffer.concat([prefix, xbuf, ybuf]);
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return pub;
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};
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module.exports = require('soop')(Point);
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