prevent IE from interpreting HTML MIME type

Add X-Content-Type-Options header to prevent Internet Explorer
from interpreting the MIME type of a server answer on its own,
which could lead to security risks.

Signed-off-by: Peter Müller <peter.mueller@link38.eu>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

config/httpd/vhosts.d/captive.conf

@@ -9,6 +9,8 @@ Listen 1013
 	# code was entered.
 	KeepAlive Off
 
+	Header always set X-Content-Type-Options nosniff
+
 	ScriptAlias /cgi-bin/ /srv/web/ipfire/cgi-bin/captive/
 	Alias /assets/ /srv/web/ipfire/html/captive/assets/
 

config/httpd/vhosts.d/ipfire-interface-ssl.conf

@@ -3,10 +3,12 @@
     RewriteEngine on
     RewriteCond %{REQUEST_METHOD} ^(TRACE|TRACK|OPTIONS)
     RewriteRule .* - [F]
+
     DocumentRoot /srv/web/ipfire/html
     ServerAdmin root@localhost
     ErrorLog /var/log/httpd/error_log
     TransferLog /var/log/httpd/access_log
+
     SSLEngine on
     SSLProtocol all -SSLv2 -SSLv3
     SSLCipherSuite ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES128-SHA256:AES128-SHA:CAMELLIA128-SHA:AES256-GCM-SHA384:AES256-SHA256:AES256-SHA:CAMELLIA256-SHA
@@ -18,6 +20,8 @@
     SSLCertificateFile /etc/httpd/server-ecdsa.crt
     SSLCertificateKeyFile /etc/httpd/server-ecdsa.key
 
+    Header always set X-Content-Type-Options nosniff
+
     <Directory /srv/web/ipfire/html>
         Options ExecCGI
         AllowOverride None

config/httpd/vhosts.d/ipfire-interface.conf

@@ -6,6 +6,8 @@
     RewriteCond %{REQUEST_METHOD} ^(TRACE|TRACK|OPTIONS)
     RewriteRule .* - [F]
 
+    Header always set X-Content-Type-Options nosniff
+
     <Directory /srv/web/ipfire/html>
         Options ExecCGI
         AllowOverride None