title: How can I limit files in S3 based on their extension?
body: <p>I'm serving a static website using an Amazon S3 bucket.  I know that I can limit read access to certain "folders" (really keys, since S3 doesn't have folders) but what I'd really like to do is limit access by file extension.</p>
  
  <p>In other words, I want to say "give read access to everyone for any file in this bucket, as long as that file ends in htm/css/js/png"; is that possible?</p>
  
  <p>(As an aside, my concern is that I will accidentally upload a .git file, or something similar that I don't want to show to the world; setting a security policy to prevent such files from being shown seems safer than trusting myself to never accidentally upload the wrong file).</p>