nginx: proxy files from S3. Let's masking the URL by pass Expires timestamp as e and Signature as st. For instance the basis URL is https://yourbucket.s3.amazonaws.com/readme.txt?AWSAccessKeyId=YOURONLYACCESSKEY&Signature=sagw4gsafdhsd&Expires=3453445231 Source: https://coderwall.com/p/rlguog

gistfile1.txt

location ~* ^/proxy_private_file/(.*) {
  set $s3_bucket        'your_bucket.s3.amazonaws.com';
  set $aws_access_key   'AWSAccessKeyId=YOUR_ONLY_ACCESS_KEY';
  set $url_expires      'Expires=$arg_e';
  set $url_signature    'Signature=$arg_st';
  set $url_full         '$1?$aws_access_key&$url_expires&$url_signature';

  proxy_http_version     1.1;
  proxy_set_header       Host $s3_bucket;
  proxy_set_header       Authorization '';
  proxy_hide_header      x-amz-id-2;
  proxy_hide_header      x-amz-request-id;
  proxy_ignore_headers   "Set-Cookie";
  proxy_buffering        off;
}