How to implement XML-safe private Amazon S3 URLs? - amazon-s3

Question

On my photography website, I am storing photos on Amazon S3. To actually display them on the website, I am using signed URLs. This means that image URLs expire. Only the web application itself is able to generate valid image file URLs.
An example URL would look like this:
http://media.jungledragon.com/images/1849/21346_small.JPG?AWSAccessKeyId=05GMT0V3GWVNE7GGM1R2&Expires=1411603210&Signature=9MMO3zEXECtvB0w%2FuMEN8obt1ow%3D
Note that by the time you read this, that URL may have already expired. That's ok, the question is about the format.
Whilst the above URL format works fine on the website, it breaks XML files. The reason for this is the & character, which should be escaped.
For example, I'm trying to implement Windows 8.1 live tiles for the website, which you can link to an RSS feed. My RSS feed is here:
http://www.jungledragon.com/all/rss/promoted
That feed will work in most RSS readers, however, the Windows 8 tile builder (http://www.buildmypinnedsite.com/en) is particularly strict about the XML being valid. Here you can see the error it throws on said feed:
http://notifications.buildmypinnedsite.com/?feed=http://www.jungledragon.com/all/rss/promoted&id=1
Now, my simple thinking was to encode the & that are part of the signed URLs, by & or &. Whilst that may make the XML valid, unfortunately S3 does not accept & to be encoded. When used like that, the image will no longer load.
I'm wondering whether I am in a circular problem that cannot be solved?

Answer 1

I have had many similar problems with RSS feeds. XML documents should always use & (or an equivalent like & or &). If a reader is not capable of extracting the URL properly, then the reader is the culprit, not you. But I can tell you that reader programmers will disagree with you.
If you are a programmer, you could fix the problem by having a redirect, but that's a bit of work. So you'd retrieve the URL from S3, save that in your database and create a URL on your website such as http://www.jungledragon.com/images/123 and link the S3 URL with your images/123 page. Now when someone goes to page images/123, you retrieve the URL you saved from your S3 server.
Actually, if the URL http://www.jungledragon.com/images/123 is a reference to your image, you can get the S3 URL at that time and do the redirect on the fly!