title: Message Integrity Check with HTTP headers since Content-MD5 was deprecated?
body: <p>Making a REST web server mainly based on large files uploads / downloads, I want to be able to check the file integrity. I believed that the proper way to do it was using Content-MD5 HTTP header [0] as proved useful by aws experience [1].</p>
  
  <p>However, much to my dismay, I recently learned that it was (to be ?) deprecated [2].</p>
  
  <p>The deprecation discussion did not give any workaround hint, so I am asking you :</p>
  
  <p>Should I still decide to use a Content-MD5 HTTP header ?</p>
  
  <p>Should I use an ETag with the same meaning (base64 encoding of the md5sum) ?</p>
  
  <p>Should I use an ?md5sum=XXX parameter ?</p>
  
  <p>Is there a better solution altogether ?</p>
  
  <p>Thanks for your insights.</p>
  
  <p>Best Regards,
  B.</p>
  
  <p>[0] <a href="https://webmasters.stackexchange.com/questions/2924/">https://webmasters.stackexchange.com/questions/2924/</a></p>
  
  <p>[1] <a href="http://developer.amazonwebservices.com/connect/thread.jspa?threadID=22709" rel="nofollow noreferrer">http://developer.amazonwebservices.com/connect/thread.jspa?threadID=22709</a></p>
  
  <p>[2] <a href="http://trac.tools.ietf.org/wg/httpbis/trac/ticket/178" rel="nofollow noreferrer">http://trac.tools.ietf.org/wg/httpbis/trac/ticket/178</a></p>