ecdh-es/lib/util.js

Elliptic Curve Diffie-Hellman with ephemeral-static keys implementation for NodeJS

// Generated by CoffeeScript 1.8.0
(function() {
  var BigInt, buff_eq, createHash, createHmac, get_pub, hmac, rand, rand_key, randomBuffer, reader, sha256, sha512, _ref,
    __slice = [].slice;

  BigInt = require('bigi');

  _ref = require('crypto'), createHash = _ref.createHash, createHmac = _ref.createHmac;

  randomBuffer = require('secure-random').randomBuffer;

  reader = function(buff, pos) {
    if (pos == null) {
      pos = 0;
    }
    return function(len) {
      if (len != null) {
        return buff.slice(pos, (pos += len));
      } else {
        return buff.slice(pos);
      }
    };
  };

  sha256 = function(d) {
    return createHash('sha256').update(d).digest();
  };

  sha512 = function(d) {
    return createHash('sha512').update(d).digest();
  };

  hmac = function() {
    var d, data, h, key, _i, _len;
    key = arguments[0], data = 2 <= arguments.length ? __slice.call(arguments, 1) : [];
    h = createHmac('sha256', key);
    for (_i = 0, _len = data.length; _i < _len; _i++) {
      d = data[_i];
      h.update(d);
    }
    return h.digest();
  };

  rand = function() {
    var entropy;
    entropy = 1 <= arguments.length ? __slice.call(arguments, 0) : [];
    return hmac.apply(null, [randomBuffer(32)].concat(__slice.call(entropy)));
  };

  rand_key = function() {
    var curve, entropy;
    curve = arguments[0], entropy = 2 <= arguments.length ? __slice.call(arguments, 1) : [];
    return BigInt.fromBuffer(rand.apply(null, entropy)).mod(curve.n);
  };

  get_pub = function(curve, privkey) {
    return curve.G.multiply(privkey).getEncoded(true);
  };

  buff_eq = function(a, b) {
    return a.toString('hex') === b.toString('hex');
  };

  module.exports = {
    reader: reader,
    sha256: sha256,
    sha512: sha512,
    hmac: hmac,
    rand: rand,
    rand_key: rand_key,
    get_pub: get_pub,
    buff_eq: buff_eq
  };

}).call(this);