NodeJS Crypto custom padding example

nodeJSCustomPadding.js

// Following an answer I posted to my question here: 
// http://stackoverflow.com/questions/21856892/node-crypto-aes256-cbc-0x0-padding-example/21858749#21858749


//I'm expecting a utf8 encoded string
function customPadding(str, blockSize, padder, format) {
  str = new Buffer(str,"utf8").toString(format);
  //1 char = 8bytes
  var bitLength = str.length*8;

  if(bitLength < blockSize) {
    for(i=bitLength;i<blockSize;i+=8) {
      str += padder;
    }
  } else if(bitLength > blockSize) {
    while((str.length*8)%blockSize != 0) {
      str+= padder;
    }
  }
  return new Buffer(str, format).toString("utf8");
}


function encrypt(str) {
  var cipher = crypto.createCipheriv('aes-256-cbc', key, iv).setAutoPadding(false);
  str = customPadding(str, 256, 0x0, "hex"); // magic happens here
  var crypt = cipher.update(str, 'utf8', 'base64');
  crypt += cipher.final("base64");
  return crypt;
}

var t = encrypt("dude");