magarity
asked on
invisible apache
I'm running Apache on a firewall box (I know, bad, bad, but I don't have another machine) and so to be as paranoid as possible, I'd like it to NOT send out 404 messages. If someone probes my box with a generic port 80 request for say, index.html (which does not exist) instead of the exact name of one of my html files, Apache should not respond in any way. I've spent some time digging through the httpd.conf file, but the closest I can find is an option to make your own message rather than Apache's generic 404 message. I'd like no message at all.
Another alternative is to use mod_rewrite to redirect the failing request to another webserver.
http://httpd.apache.org/docs/misc/rewriteguide.html
look under "Redirect Failing URLs To Other Webserver" section.
--- exact copy from that section;
Description:
A typical FAQ about URL rewriting is how to redirect failing requests on webserver A to webserver B. Usually this is done via ErrorDocument CGI-scripts in Perl, but there is also a mod_rewrite solution. But notice that this is less performant than using a ErrorDocument CGI-script!
Solution:
The first solution has the best performance but less flexibility and is less error safe: RewriteEngine on
RewriteCond /your/docroot/%{REQUEST_FI
RewriteRule ^(.+) http://webserverB.dom/$1
The problem here is that this will only work for pages inside the DocumentRoot. While you can add more Conditions (for instance to also handle homedirs, etc.) there is better variant:
RewriteEngine on
RewriteCond %{REQUEST_URI} !-U
RewriteRule ^(.+) http://webserverB.dom/$1
This uses the URL look-ahead feature of mod_rewrite. The result is that this will work for all types of URLs and is a safe way. But it does a performance impact on the webserver, because for every request there is one more internal subrequest. So, if your webserver runs on a powerful CPU, use this one. If it is a slow machine, use the first approach or better a ErrorDocument CGI-script.
I would think the ErrorDocument handler is much simpler. But if you want more control on where the diversion, mod_rewrite would be good.
http://httpd.apache.org/docs/misc/rewriteguide.html
look under "Redirect Failing URLs To Other Webserver" section.
--- exact copy from that section;
Description:
A typical FAQ about URL rewriting is how to redirect failing requests on webserver A to webserver B. Usually this is done via ErrorDocument CGI-scripts in Perl, but there is also a mod_rewrite solution. But notice that this is less performant than using a ErrorDocument CGI-script!
Solution:
The first solution has the best performance but less flexibility and is less error safe: RewriteEngine on
RewriteCond /your/docroot/%{REQUEST_FI
RewriteRule ^(.+) http://webserverB.dom/$1
The problem here is that this will only work for pages inside the DocumentRoot. While you can add more Conditions (for instance to also handle homedirs, etc.) there is better variant:
RewriteEngine on
RewriteCond %{REQUEST_URI} !-U
RewriteRule ^(.+) http://webserverB.dom/$1
This uses the URL look-ahead feature of mod_rewrite. The result is that this will work for all types of URLs and is a safe way. But it does a performance impact on the webserver, because for every request there is one more internal subrequest. So, if your webserver runs on a powerful CPU, use this one. If it is a slow machine, use the first approach or better a ErrorDocument CGI-script.
I would think the ErrorDocument handler is much simpler. But if you want more control on where the diversion, mod_rewrite would be good.
ASKER
I tried redirecting it to both /dev/NULL and 127.0.0.1 but neither worked; I still get an error message about the page missing rather than 'can't find server'
I would presume you adopt the ErrorDocument approach.
The directive will take an HTML document, or a CGI scripts, or anything that is understood by the Web client. Ie, the data returned must be "web-enabled", following the standard so called.
At this point I kinda confused on what you are trying to achive. Do you have a legitimate website hosted on that machine that you want public internet to be able to reach? Which you want to block from robots?
Or you do not want people to probe you port 80 at all.
If you happens to have any web hosting running behind the firewall, and the firewall should be opening port 80, then the protection method you are looking at really depends on how the firewall "Secure" the port. Method that I can think of now are;
(1) Relay TCP/80 to some internal server.
- Direct datastream from remote is allowed to go thru to your internal server only to port 80. OR
(2) Proxy the service for the internal server.
- The firewall is doing the "fetching" and sends back the pages/data to remote client.
Please elaborate
The directive will take an HTML document, or a CGI scripts, or anything that is understood by the Web client. Ie, the data returned must be "web-enabled", following the standard so called.
At this point I kinda confused on what you are trying to achive. Do you have a legitimate website hosted on that machine that you want public internet to be able to reach? Which you want to block from robots?
Or you do not want people to probe you port 80 at all.
If you happens to have any web hosting running behind the firewall, and the firewall should be opening port 80, then the protection method you are looking at really depends on how the firewall "Secure" the port. Method that I can think of now are;
(1) Relay TCP/80 to some internal server.
- Direct datastream from remote is allowed to go thru to your internal server only to port 80. OR
(2) Proxy the service for the internal server.
- The firewall is doing the "fetching" and sends back the pages/data to remote client.
Please elaborate
ASKER
"Do you have a legitimate website hosted on that machine that you want public internet to be able to reach?"
Yes and no. It's just for my investment club. General public doesn't neeed to know what I am doing with my and my friends' money with how much.
"Which you want to block from robots?"
Robots, spiders, and mainly script kiddies trying to hijack the box to use for DDoS fun.
"(1) Relay TCP/80 to some internal server.
The only other machine is a power hungry TBird. I'm hoping to use the low power firewall box. It is already set to a funky port, not 80, but a general scan by nmap shows the port open and accepting html requests. THAT is what I don't want; someone's random nmap should only show the ssh port, which is more secure than a web server port.
"(2) Proxy the service for the internal server."
Hmm, I'm not sure what you mean by this, nevermind how to do it.
Thanks for the suggestions so far.
Yes and no. It's just for my investment club. General public doesn't neeed to know what I am doing with my and my friends' money with how much.
"Which you want to block from robots?"
Robots, spiders, and mainly script kiddies trying to hijack the box to use for DDoS fun.
"(1) Relay TCP/80 to some internal server.
The only other machine is a power hungry TBird. I'm hoping to use the low power firewall box. It is already set to a funky port, not 80, but a general scan by nmap shows the port open and accepting html requests. THAT is what I don't want; someone's random nmap should only show the ssh port, which is more secure than a web server port.
"(2) Proxy the service for the internal server."
Hmm, I'm not sure what you mean by this, nevermind how to do it.
Thanks for the suggestions so far.
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ASKER
Doesn't look like there's an Apache way to do it, so I'm accepting this part of samri's comment as answer because that's what I'll end up doing:
"use firewall ... that only accept connection from a predefined hosts"
I was afraid this would end up being the answer before asking; i't a pain to figure out all the club members' IPs and enter them in the iptables script.
"use firewall ... that only accept connection from a predefined hosts"
I was afraid this would end up being the answer before asking; i't a pain to figure out all the club members' IPs and enter them in the iptables script.
Yes, you can do it in apache also;
Add the following directive in Global Server config,
<Location />
Order deny,allow
Deny from all
# Allow from 164.137.139.219 164.137.158.119
Allow from 1.2.3.4 10.2.3.0/255.255.255.0
</Location>
hope this gives you another alternative. But, those IP which are denied will still be able to connect to your Apache, but will be getting 403 Forbidden message.
cheers
Add the following directive in Global Server config,
<Location />
Order deny,allow
Deny from all
# Allow from 164.137.139.219 164.137.158.119
Allow from 1.2.3.4 10.2.3.0/255.255.255.0
</Location>
hope this gives you another alternative. But, those IP which are denied will still be able to connect to your Apache, but will be getting 403 Forbidden message.
cheers
If you do then here is a solution
ErrorDocument 404 http://www.domain.com/page.html(What ever you want)
Other than that I don't know.
Sorry
Probably you are not looking for this solution