title: Set AES key in iOS from a byte array
body: <p>My service gives me a key as a byte array. For example：</p>
  
  <pre><code>(byte) 0x16, (byte) 0xBB, (byte) 0xAB, (byte) 0xEA, (byte) 0x85, (byte) 0xA7,(byte) 0xD4, (byte) 0xE5, (byte) 0x2F, (byte) 0x7F, (byte) 0x28, (byte) 0x4C, (byte) 0x96, (byte) 0x7D,
  </code></pre>
  
  <p>In iOS, the AES key is a string. I am trying to use this byte array as a key in iOS.</p>