Update- Apple sells an adapter. One for 29$ and one for $39. Check the link below if you need an adapter.
The $29 model is just the adapter. The $39 model is cord + adapter. The $39 option might be a better choice for those who use a case as it is the same size as the charging cable. The $29 model plugs into the bottom of your phone and might have some fitment issues if you have a case. I will update again once I get my adapter and verify that it works for AUX input.
Lightning to 30-pin Adapter (0.2 m) - Apple Store (U.S.)