@okxweb3/crypto-lib
Version:
A base package for @okxweb3/coin-*
126 lines • 4 kB
JavaScript
'use strict';
var BN = require('bn.js/lib/bn');
var inherits = require('inherits');
var Base = require('./base');
var utils = require('../utils');
function MontCurve(conf) {
Base.call(this, 'mont', conf);
this.a = new BN(conf.a, 16).toRed(this.red);
this.b = new BN(conf.b, 16).toRed(this.red);
this.i4 = new BN(4).toRed(this.red).redInvm();
this.two = new BN(2).toRed(this.red);
this.a24 = this.i4.redMul(this.a.redAdd(this.two));
}
inherits(MontCurve, Base);
module.exports = MontCurve;
MontCurve.prototype.validate = function validate(point) {
var x = point.normalize().x;
var x2 = x.redSqr();
var rhs = x2.redMul(x).redAdd(x2.redMul(this.a)).redAdd(x);
var y = rhs.redSqrt();
return y.redSqr().cmp(rhs) === 0;
};
function Point(curve, x, z) {
Base.BasePoint.call(this, curve, 'projective');
if (x === null && z === null) {
this.x = this.curve.one;
this.z = this.curve.zero;
}
else {
this.x = new BN(x, 16);
this.z = new BN(z, 16);
if (!this.x.red)
this.x = this.x.toRed(this.curve.red);
if (!this.z.red)
this.z = this.z.toRed(this.curve.red);
}
}
inherits(Point, Base.BasePoint);
MontCurve.prototype.decodePoint = function decodePoint(bytes, enc) {
return this.point(utils.toArray(bytes, enc), 1);
};
MontCurve.prototype.point = function point(x, z) {
return new Point(this, x, z);
};
MontCurve.prototype.pointFromJSON = function pointFromJSON(obj) {
return Point.fromJSON(this, obj);
};
Point.prototype.precompute = function precompute() {
};
Point.prototype._encode = function _encode() {
return this.getX().toArray('be', this.curve.p.byteLength());
};
Point.fromJSON = function fromJSON(curve, obj) {
return new Point(curve, obj[0], obj[1] || curve.one);
};
Point.prototype.inspect = function inspect() {
if (this.isInfinity())
return '<EC Point Infinity>';
return '<EC Point x: ' + this.x.fromRed().toString(16, 2) +
' z: ' + this.z.fromRed().toString(16, 2) + '>';
};
Point.prototype.isInfinity = function isInfinity() {
return this.z.cmpn(0) === 0;
};
Point.prototype.dbl = function dbl() {
var a = this.x.redAdd(this.z);
var aa = a.redSqr();
var b = this.x.redSub(this.z);
var bb = b.redSqr();
var c = aa.redSub(bb);
var nx = aa.redMul(bb);
var nz = c.redMul(bb.redAdd(this.curve.a24.redMul(c)));
return this.curve.point(nx, nz);
};
Point.prototype.add = function add() {
throw new Error('Not supported on Montgomery curve');
};
Point.prototype.diffAdd = function diffAdd(p, diff) {
var a = this.x.redAdd(this.z);
var b = this.x.redSub(this.z);
var c = p.x.redAdd(p.z);
var d = p.x.redSub(p.z);
var da = d.redMul(a);
var cb = c.redMul(b);
var nx = diff.z.redMul(da.redAdd(cb).redSqr());
var nz = diff.x.redMul(da.redISub(cb).redSqr());
return this.curve.point(nx, nz);
};
Point.prototype.mul = function mul(k) {
var t = k.clone();
var a = this;
var b = this.curve.point(null, null);
var c = this;
for (var bits = []; t.cmpn(0) !== 0; t.iushrn(1))
bits.push(t.andln(1));
for (var i = bits.length - 1; i >= 0; i--) {
if (bits[i] === 0) {
a = a.diffAdd(b, c);
b = b.dbl();
}
else {
b = a.diffAdd(b, c);
a = a.dbl();
}
}
return b;
};
Point.prototype.mulAdd = function mulAdd() {
throw new Error('Not supported on Montgomery curve');
};
Point.prototype.jumlAdd = function jumlAdd() {
throw new Error('Not supported on Montgomery curve');
};
Point.prototype.eq = function eq(other) {
return this.getX().cmp(other.getX()) === 0;
};
Point.prototype.normalize = function normalize() {
this.x = this.x.redMul(this.z.redInvm());
this.z = this.curve.one;
return this;
};
Point.prototype.getX = function getX() {
this.normalize();
return this.x.fromRed();
};
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