var aes = require('./aes');
var Transform = require('./cipherBase');
var inherits = require('inherits');

inherits(StreamCipher, Transform);
module.exports = StreamCipher;
function StreamCipher(mode, key, iv, decrypt) {
  if (!(this instanceof StreamCipher)) {
    return new StreamCipher(mode, key, iv);
  }
  Transform.call(this);
  this._cipher = new aes.AES(key);
  this._prev = new Buffer(iv.length);
  this._cache = new Buffer('');
  this._secCache = new Buffer('');
  this._decrypt = decrypt;
  iv.copy(this._prev);
  this._mode = mode;
}
StreamCipher.prototype._update = function (chunk) {
  return this._mode.encrypt(this, chunk, this._decrypt);
};
StreamCipher.prototype._final = function () {
  this._cipher.scrub();
};