.htaccess Authorization header missing

Can you tell what's wrong with this script ? Need to add Authorization header, but it does not.

<IfModule mod_rewrite.c>
    RewriteEngine On

    RewriteCond %{HTTP:Authorization} .+
    RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]

    RewriteCond %{REQUEST_URI} !^public
    RewriteRule ^(.*)$ public/$1 [L]
</IfModule>

via Chebli Mohamed