function base32tohex (str) {
  var base32chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
  var padding = "=";

  var bits = "";
  var length = str.length - 8;
  if(length < 0) {
    length = str.length;
  }
  for(var i = 0; i < length; i++) {
    var val = base32chars.indexOf(str[i]);
    bits += ("00000" + val.toString(2)).slice(-5);
  }
  if(length < str.length) {
    var lastblock = str.substr(length);        
    var lastblocklength;
    var lastblocknumberofbits;
    if (lastblock[2] === padding) {
      lastblocklength = 2;
      lastblocknumberofbits = 8;
    } else if (lastblock[4] === padding) {
      lastblocklength = 4;
      lastblocknumberofbits = 16;
    } else if (lastblock[5] === padding) {
      lastblocklength = 5;
      lastblocknumberofbits = 24;
    } else if (lastblock[7] === padding) {
      lastblocklength = 7;
      lastblocknumberofbits = 32;
    } else {
      lastblocklength = 8;
      lastblocknumberofbits = 40;
    }
    for(i = length; i < length + lastblocklength; i++) {
      var lastblockval = base32chars.indexOf(str[i]);
      bits += ("00000" + lastblockval.toString(2)).slice(-5).substring(0, lastblocknumberofbits);
      lastblocknumberofbits -= 5;
    }
  }

  var hex = "";
  for( i = 0; i + 4 <= bits.length; i+=4) {
    var chunk = bits.substr(i, 4);
    hex += parseInt(chunk, 2).toString(16) ;
  }
  return hex;
}