bitcoin-elliptic/lib/elliptic/curves.js

EC cryptography

'use strict';

var curves = exports;

var hash = require('hash.js');
var curve = require('./curve');
var utils = require('./utils');

var assert = utils.assert;

function PresetCurve(options) {
  if (options.type !== 'short')
    throw new Error('invalid curve type')
  this.curve = new curve.short(options);
  this.g = this.curve.g;
  this.n = this.curve.n;
  this.hash = options.hash;

  assert(this.g.validate(), 'Invalid curve');
  assert(this.g.mul(this.n).isInfinity(), 'Invalid curve, G*N != O');
}
curves.PresetCurve = PresetCurve;

function defineCurve(name, options) {
  Object.defineProperty(curves, name, {
    configurable: true,
    enumerable: true,
    get: function() {
      var curve = new PresetCurve(options);
      Object.defineProperty(curves, name, {
        configurable: true,
        enumerable: true,
        value: curve
      });
      return curve;
    }
  });
}

var pre;
try {
  pre = require('./precomputed/secp256k1');
} catch (e) {
  pre = undefined;
}

defineCurve('secp256k1', {
  type: 'short',
  prime: 'k256',
  p: 'ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff fffffffe fffffc2f',
  a: '0',
  b: '7',
  n: 'ffffffff ffffffff ffffffff fffffffe baaedce6 af48a03b bfd25e8c d0364141',
  h: '1',
  hash: hash.sha256,

  // Precomputed endomorphism
  beta: '7ae96a2b657c07106e64479eac3434e99cf0497512f58995c1396c28719501ee',
  lambda: '5363ad4cc05c30e0a5261c028812645a122e22ea20816678df02967c1b23bd72',
  basis: [
    {
      a: '3086d221a7d46bcde86c90e49284eb15',
      b: '-e4437ed6010e88286f547fa90abfe4c3'
    },
    {
      a: '114ca50f7a8e2f3f657c1108d9d44cfd8',
      b: '3086d221a7d46bcde86c90e49284eb15'
    }
  ],

  gRed: false,
  g: [
    '79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798',
    '483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8',
    pre
  ]
});