title: ipa extraction after you download an app from iTunes
body: <p>We are currently providing ios app via Itunes. The main function of the app is to verify `app integrity' and it is done by checking hash value (sha256) of the execution file in .ipa once we download it. </p>
  
  <p>With the 32bit app we downloaded from iTunes, we can extract .ipa file to get execution file without problems. However, it does not seem to be possible with 64bit ios apps. (maybe there is a way and we couldn't find it. if this is the case please enlighten us.) Since we are planning provide our service both with 32 and 64bit, we do need to extract execution file from 64bit app.</p>
  
  <p>So there are two questions we would like to ask regarding on this ipa extraction.
  1. The hash value(sha256) of the app before we upload to iTunes and the value after we download it from iTunes is different. Why is that?
  2. Is there any way we can extract .ipa (32/64 bit both) after we download the app from iTunes?</p>