title: S3 signed URL redirect on iphone download failed
body: <p>I've developed an Angular 2 application with a Node.js backend. I am using the aws-sdk to store files from the application. 
  There is an function in the app where a user can download a pdf which has been uploaded to the app (and stored on s3). Essentially, the app requests a signedurl from s3 for the specific object, as in the code block below. </p>
  
  <pre><code>var params = {
              Bucket: projectid,
              Key: docName,
              VersionId: versionid,
              ResponseContentDisposition: 'attachment; filename ="' + docName+ '_' + versionid + '.pdf"'
  
          };
          var url = {
              link: s3.getSignedUrl('getObject', params)
          }
          res.status(200).send(url);
  </code></pre>
  
  <p>This url is returned to the front end and then angular opens the signed url in a new browser window, as in the line of code below.</p>
  
  <pre><code>        window.open(url.link.toString());
  </code></pre>
  
  <p>This works perfectly fine on desktops and android phones. 
  When I try to open it on an iPhone, it opens a new tab, shows an icon of a file and then it says 'download failed'. The link in the browser however is correct and would work on any other device as mentioned.</p>
  
  <p>I need to get this to work on all devices, could anyone possibly suggest a different way to download the file through the angular frontend which is iPhone friendly?</p>