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.codeUnitAt(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);
}

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

prng_newstate() {
 return new Arcfour();
}