var xor = require('../xor');
function getBlock(self) {
  self._prev = self._cipher.encryptBlock(self._prev);
  return self._prev;
}
exports.encrypt = function (self, chunk) {
  while (self._cache.length < chunk.length) {
    self._cache = Buffer.concat([self._cache, getBlock(self)]);
  }
  var pad = self._cache.slice(0, chunk.length);
  self._cache = self._cache.slice(chunk.length);
  return xor(chunk, pad);
};