title: Uploadifive and Amazon s3 - Origin is not allowed by Access-Control-Allow-Origin
body: <p>I am trying to get <strong>Uploadifive</strong> (the HTML5 version of Uploadify) to work with Amazon S3. We already have Uploadify working, but a lost of our visitors use Safari without flash so we need Uploadifive as well.</p>
  
  <p>I am looking to make a POST but the problem is that the pre-flight OPTIONS request that Uploadifive sends gets a "403 Origin  is not allowed by Access-Control-Allow-Origin".</p>
  
  <p>The CORS rules on Amazon are set to allow * origin, so I see no reason for Amazon to refuse the request (and note that it accepts the requests coming from Flash, although I don't know if Flash sends an OPTIONS request before the POST). If I haven't made some big mistake in my settings on Amazon I assume this has something to do with Uploadifive not being set up for cross-origin requests, but I can find no info on how to check/do this or even how to change the headers sent on the request.</p>
  
  <p>Has anyone tried using Uploadifive with Amazon S3, and how have you gotten around this problem?</p>
  
  <p>My S3 CORS setting:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"&gt;
  &lt;CORSRule&gt;
      &lt;AllowedOrigin&gt;*&lt;/AllowedOrigin&gt;
      &lt;AllowedMethod&gt;GET&lt;/AllowedMethod&gt;
      &lt;MaxAgeSeconds&gt;3000&lt;/MaxAgeSeconds&gt;
      &lt;AllowedHeader&gt;Authorization&lt;/AllowedHeader&gt;
  &lt;/CORSRule&gt;
  &lt;CORSRule&gt;
      &lt;AllowedOrigin&gt;*&lt;/AllowedOrigin&gt;
      &lt;AllowedMethod&gt;POST&lt;/AllowedMethod&gt;
  &lt;/CORSRule&gt;
  </code></pre>
  
  <p></p>
  
  <p>Edit:
  After testing Chrome with the --disable-web-security flag I stopped getting 403:s, so it does seem like it is Uploadifive that is not setting cross domain headers properly. The question has now become, how do you modify the cross domain settings of Uploadifive?</p>