How to exclude certain filenames from being Hotlinked Blocked in .htaccess

Question

I've currently got the following in my .htaccess of my photo folder.

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?siteabc.com [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?sitexyz.com [NC]
RewriteRule \.(jpg|jpeg|png|gif)$ http://example.com/images/bandwidth.png [NC,R,L]

This blocks all not allowed domains from hotlinking our photo files and displays the http://example.com/images/bandwidth.png in it's place.

However, what I would like to do is to allow sites to be able to hotlinked our thumbnails. The thumbnail images have this sort of filename format

filenameabc_100_cw100_ch100_thumb.jpg
filenameabc_100_cw100_ch100_thumb.png
filenamexyz123_100_cw100_ch100_thumb.png

eg the filenames all end with _thumb.ext

So what I would like to do is to modify the above .htaccess to globally block all access with the exception of the filenames ending in thumb eg *_thumb.jpg or *_thumb.png

I don't have the first idea about how to write such a rule.

If anyone has any ideas I would be most grateful.

Answer 1

Modifying the rule-set in the question:

You may try this:

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?siteabc.com [NC]
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?sitexyz.com [NC]
# Add this other exception
RewriteCond %{REQUEST_URI}  !_thumb\.  [NC]
RewriteRule \.(jpg|jpeg|png|gif)$ http://example.com/images/bandwidth.png [NC,R,L]