title: iPhone JPG image has non-standard magic bytes ff d8 ff e1?
body: <p>My web app checks the first four bytes against the file extension before accepting uploaded images. A coworker showed me images from his iPhone which are being rejected. These have a different fourth byte (e1 = 225 instead of the expected e0 = 224).</p>
  <p>Is this usual for iPhones? Are there other possible magic byte strings used in JPG files?</p>
  <p>Edit: found this useful list: <a href="http://www.garykessler.net/library/file_sigs.html" rel="nofollow noreferrer">http://www.garykessler.net/library/file_sigs.html</a></p>