This extension protects everything within /fileadmin/ based on associated folder and file restrictions (visibility, user groups and dates of publication):

Unlike other similar extensions securing the File Abstraction Layer (FAL) of TYPO3, this extension aims at making it straightforward to block direct access to your sensitive assets.

No need to configure anything, just install and enable as usual, block direct access at the server level (Apache/Nginx see below) and... that's it!

Our motto? KISS!

Edit file .htaccess to read:

RewriteCond %{REQUEST_URI} !/fileadmin/_processed_/.*$
RewriteRule ^fileadmin/.*$ %{ENV:CWD}index.php [QSA,L]

BEWARE: Be sure to add this rule before any other related rule.

Edit your server block to read:

location / {
    rewrite ^/fileadmin/(?!(_processed_/)) /index.php last;

    # snip
}

or, if that better fits your setup, like that:

location ~ /fileadmin/(?!(_processed_/)) {
    rewrite ^(.+)$ /index.php last;
}

In case you try to access a restricted file and do not have the right to do so, the logical HTTP status code to use should be either a 403 Forbidden (or possibly a 401 Unauthorized) but by doing so, you make it clear for a malicious user that the resource exists but is not accessible.

We prefer, at least for the time being (see ideas for the future below) to issue a 404 Not Found instead.

• Instead of denying access altogether if the user is not authenticated at all, it could be useful to redirect to a login page instead.

A more complete documentation can be found on https://docs.typo3.org/p/causal/fal-protect/1.1/en-us/.