Converting short upload URLs to full URLs

I may be barking up the wrong tree here, so apologies if I am - but any pointers very much welcome!

There are some threads in our Discourse site which are displayed in part on our main website. Because the cooked version of a post contains all the HTML for the lightbox, which we don’t want on the main site, I’m working with the raw version of a post.

One thing that’s tripping me up is the file upload URLs. How can I convert an upload:// URL to a full URL? I’ve tried searching and come across SHA1 and Base62, but apart from that, no matter what I try, I can’t get the full URL.

As I said, I may looking at the wrong thing, or there’s (likely) to be an easier way to these things, so any advice welcome!

Thanks in advance


First base62 decode using the inverted character set, then hex encode the result.

In Python code it looks like this:

rebase = hex(base62.decode(base, base62.CHARSET_INVERTED))[2:].zfill(40)


Thanks for the swift reply @michaeld. Will give it a go later today :slight_smile:

For anyone interested and doing this in PHP, I used a composer library called base62 by tuupola.

This is the code I used:


$base62 = new Tuupola\Base62(["characters" => Tuupola\Base62::INVERTED]);

/** Set the original file name, excluding any file extensions */
$s = "r3AYqESanERjladb4vBB7VsMBm6";

/** Decode, convert to hex */
$decoded = $base62->decode($s);

/** Expected result: bda2c513e1da04f7b4e99230851ea2aafeb8cc4e */
echo bin2hex($decoded);