title: IOS - How do I AES decrypt a large file if the file is too large to load all of it into memory?
body: <p>I know how to AES encrypt and decrypt an <code>NSData</code>, but that requires loading the whole file into memory first.</p>
  
  <p>Say I have a 50mb encrypted file called <code>data.dat.enc</code>, how can I decrypt it to a file <code>data.dat</code> without having to first load it all into memory?</p>