Getting FilesMatch and Satisfy Any to work with sub directories

I'm trying to lock down a tree of directories (but allow through image files) using the following .htaccess rule

AuthType Basic
AuthName "Test Sites. *Please Contact xxxxxxx for access.*"
AuthUserFile /home/www/testsites/.htpasswd
Require valid-user

<FilesMatch "\.(gif|jpe?g|png)$">
  Satisfy Any
  Allow from all
</FilesMatch>

However, when I try it, I'm still being asked to authenticate against images if the image is not directly within the httpdocs directory.

In other words

http://www.testsites.com/test.jpg would be allowed through, but http://www.testsites.com/sitename/images/test.jpg is asking for authentication.

Any idea why this might be happening?

Solution

Try this alternative approach based on mod_setenvif:

SetEnvIfNoCase Request_URI "\.(gif|jpe?g|png)$" ALLOWED

AuthType Basic
AuthName "Test Sites. *Please Contact xxxxxxx for access.*"
AuthUserFile /home/www/testsites/.htpasswd
Require valid-user
Satisfy    any
Order      deny,allow
Deny from  all
Allow from env=ALLOWED