code: function b64toBA(s) {
    //piggyback on b64tohex for now, optimize later
    var h = b64tohex(s);
    var i;
    var a = new Array();
    for(i = 0; 2*i < h.length; ++i) {
      a[i] = parseInt(h.substring(2*i,2*i+2),16);
    }
    return a;
  }
docs: convert a base64 string to a byte/number array