parseBigInt(str,r) {
  return new BigInteger(str,r);
}

pkcs1pad2(s,n) {
  if(n < s.length + 11) {
    print("Message too long for RSA");
    return null;
  }
  var ba = new Map();
  var i = s.length - 1;
  while(i >= 0 && n > 0) ba[--n] = s.charCodeAt(i--);
  ba[--n] = 0;
  var rng = new SecureRandom();
  var x = new Map();
  while(n > 2) { // random non-zero pad
    x[0] = 0;
    while(x[0] == 0) rng.nextBytes(x);
    ba[--n] = x[0];
  }
  ba[--n] = 2;
  ba[--n] = 0;
  return new BigInteger(ba);
}

prng_newstate() {
  return new Arcfour();
}