Guide to filtering web content (http and https) with pfsense 2.3

aGeekhere

You have to create 3 files in /usr/local/www/
wpad.da
wpad.dat
proxy.pac

Each having this code

function FindProxyForURL(url, host) 
{ 
    if (isPlainHostName(host) ||
        shExpMatch(host, "*.local") ||
        isInNet(dnsResolve(host), "192.168.1.0",  "255.255.255.0"))
        return "DIRECT";

    return "PROXY 192.168.1.1:3128";
}

Instead of maintaining changes for all 3 files you can create a main file e.g. wpad.da and create a symbolic link for the other 2 files, that way all changes from wpad.da are copied over to the other files.

So now you only need to make changes to wpad.da.

kpoman

Is there any way to force safesearch (google youtube etc…) if your DNS is on a Windows Server AD but your gateway pfSense is intercepting all http on a squid instance ?

aGeekhere

@kpoman:

Is there any way to force safesearch (google youtube etc…) if your DNS is on a Windows Server AD but your gateway pfSense is intercepting all http on a squid instance ?

Read the DNS resolver part in the guide and see if you can use that method.

jopeme

I see a problem with this option and it is that many of my clients have problems to watch YouTube videos, when they search from Google, since it shows that they are restricted videos and that you have to register.

Click add under Host overrides
Host = www
Domain = youtube.com
IP = 216.239.38.120
Description = youtube
Save
NOTE: Safe search for youtube is not as advanced as google safe search, which results in a lot of safe content be filtered out.

vielfede

Hello,
Maybe I missed something, I read the entire topic, but I did not find any post about access url on different port then standard 80/443….
For example if you try to access the following site:

http://fatturazione.comieco.org:82/anagrafica.php

The proxy respond with an error message.
Loooking to the squid log I noticed that when I tried to connect to http://fatturazione.comieco.org:82/ squid tried to connect still to port 80…
To get it work, I inserted an exception on wpad configuration, something like

        if (shExpMatch(url, "http://fatturazione.comieco.org:82/*"))
        { return "DIRECT"; }

That allows the client to go out straight through the FW on port 82…. and hence now it works...

Indeed I'd like a solution to allow "different ports" work without WPAD exceptions. Otherwise you have to insert an exception for every site not using std port.
I did not notice anyone pointing out this kind of issue... Can I be the only one with this kind of issue?
Thanks in advance.

aGeekhere

I am not sure on this, if you use the transparent proxy then that only listens on port 80 and 443 for MITM.

vielfede

Finally I found out the solution… (http and https)
https://forum.pfsense.org/index.php?topic=96782.0

KARMA

I am trying to block facebook and youtube and some unwanted sites using Squid and SquidGuard filtering but those sites are't blocked. I can still access the blocked sites. Please can any one help me where i went wrong?

pfrickroll

This post is deleted!

stuck

@aGeekhere
First thank you for the detail guide. I'm running netgate 2.4.3_1 connected to TorguardVPN service and have had http transparent proxy (squid) running fine for some time. I've recently decided to add https filtering with squid/squidguard on netgate and WPAD on a separate http server. I can access the wpad files just fine using both the wpad.localdomain address or ip address. But the SSL filtering doesn't seem to work.
It seems on my system, transparent proxy only works on http sites. In order to get to https/ssl sites I have to explicitly setup my proxy address and port in windows.

Any help or hint is appreciated

aGeekhere

@stuck In squid SSL - Man In the Middle Filtering - HTTPS/SSL Interception tic Enable SSL filtering and SSL/MITM Mode set to splice all

zonda

Thank you for this guide aGeekHere!

Would you be able provide instructions on how to exclude websites from being proxied please? I have transparent proxy setup, no WPAD, SSL/MITM mode set to Splice All. Filtering web content is working great except that Microsoft Office 365 applications seem to be having connectivity issues. When user traffic is no longer being proxied, issue is resolved. Would like to exclude all Office 365 related domains/sites from the proxy.

Thank you again for any help or advice in advance.

aGeekhere

You need to set up the WPAD for windows updates and office for connections to work.

This is how it works
The WPAD directs traffic to port 80 and 443 if the programs supports it (a lot of programs do not).
Transparent proxy catches any traffic going to port 80 which is not supported by the WPAD.
SSL/MITM Mode set to splice all catches any traffic going to port 443 which is not supported by the WPAD, However this may not always work with things like windows updates and word, this is meant to be like a safety net that catches any missed connections from the WPAD.

So you need all 3.

zonda

Is it still possible to create exceptions to not proxy trusted sites with transparent proxy?
There are some specific sites that will need to bypass the proxy for some of our application to function. WPAD was used initially in our environment but some traveling users had issues with persistent proxy settings so would prefer to only use the transparent method.

aGeekhere

@zonda
Sure, the option is under ACLs in squid. If users do not want to use the WPAD (auto config proxy) then they should manually enter in the proxy settings in internet options (if using windows). Do not rely on SSL/MITM Mode splice all for all 443 traffic or else you will get connection errors. That is if you are blocking port 80 and 443 and forcing users to use the proxy.

Jopeme2000

Hello. I use your guide http and https to filter traffic but i have problems with youtube videos

Restricts many videos in an erroneous way

Do you know how i can solve it?

aGeekhere

@jopeme2000
"NOTE: Safe search for youtube is not as advanced as google safe search, which results in a lot of safe content be filtered out."

Google has to improve it, nothing you can do about it

roberz

@aGeekhere
Hi,
A great thank you for this guide. It is the most complete guide for traffic filtering on pfSense I was able to find.
I made traffic filtering work for a customer who wants porn filtering and it works. But doesn't work perfect. It works great on desktop machines while on Android phones it blocks more than required. For example: it also blocks all Skype and Facebook Messenger traffic and also blocks my RSS feed reader to connect to Internet on Android phones.
Can you explain a bit what you thought with this in june 2016 edit:
"I have found that if you have connection issues using auto config for android or other smart phones try manually setting the proxy, now opening port 80 and 443 is not needed."
Thank you.

aGeekhere

@roberz
For android phones (depending on with android version) auto config has issues so you have to manually enter in the proxy settings.

If things like Skype and Facebook Messenger are being blocked make sure you also have set up transparent proxy with splice all for SSL Man In the Middle Filtering.

The idea is
First use the WPAD to connect to the proxy (if the device has auto config issues you have to manually add it). If a program does not have proxy settings the transparent proxy and SSL Man In the Middle should catch the rest. The reason why to first use the WPAD is that some programs/software (like windows updates) have connection issues with transparent proxy and SSL Man In the Middle, splice all.

So first use the WPAD as a shortcut so you do not have to configure all devices on your network to use your proxy.
Then for devices that have auto conf issues manually config them.
Finally have the transparent proxy and SSL Man In the Middle splice all to catch any traffic that cannot use the proxy .

Hope this was helpful

marksantos

Hi sir, all step are follow, search engine n safe search is working, but some of the images in whitelist website can't load.