madeline-ton/dist/lib/prng4.js

Pure JS client-side implementation of the Telegram TON blockchain protocol

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.prng_newstate = prng_newstate;

// prng4.js - uses Arcfour as a PRNG
function Arcfour() {
  this.i = 0;
  this.j = 0;
  this.S = new Array();
} // Initialize arcfour context from key, an array of ints, each from [0..255]


function ARC4init(key) {
  var i, j, t;

  for (i = 0; i < 256; ++i) {
    this.S[i] = i;
  }

  j = 0;

  for (i = 0; i < 256; ++i) {
    j = j + this.S[i] + key[i % key.length] & 255;
    t = this.S[i];
    this.S[i] = this.S[j];
    this.S[j] = t;
  }

  this.i = 0;
  this.j = 0;
}

function ARC4next() {
  var t;
  this.i = this.i + 1 & 255;
  this.j = this.j + this.S[this.i] & 255;
  t = this.S[this.i];
  this.S[this.i] = this.S[this.j];
  this.S[this.j] = t;
  return this.S[t + this.S[this.i] & 255];
}

Arcfour.prototype.init = ARC4init;
Arcfour.prototype.next = ARC4next; // Plug in your RNG constructor here

function prng_newstate() {
  return new Arcfour();
}