Ssl filtering transparent and non-transparent

xbipin

i didnt understand that but what i need it to do is i want to block access to all sites, http and https and only allow the listed ones using squid and squidguard. the ones allowed are a few http and few https and i dont want to go about installing anything extra on client machines, is this possible?

marcelloc

@xbipin:

The ones allowed are a few http and few https and i dont want to go about installing anything extra on client machines, is this possible?

On current stable package(squid2 + squidguard), if you block domains and not urls and has clients browsers with proxy settings, then you can show squidguard error.

ssl_filtering from current squid-dev includes squidguard error message on

transparente ssl connections using domains or urls acls
non-transparent mode using url acls

With CA CRT installed on clients, you do not have Browsers cert alerts.

xbipin

basically im just blocking all domains by default and allowing the ones listed in transparent mode, i dont want it to do any content filtering, its just u block all and allow the listed and for the allowed ones u dont filter or restrict, full access.

currently on squid2 i allow domains and urls and its in transparent mode with no client side config and i squidguard gives errors as required but the problem is it does to port 80 only which is http, all i need is same but for port 443 (https) as well coz other than that all other ports r blocked for client using firewall rules

xbipin

so is this possible in squi2 or squid3-dev

transparent mode
when user goes to any https site, check its domain, if allowed then allow it direct connection or through squid, if denied then block connection and/or give error message
no client side config

currently on squid2 clients r blocked http connections to all domains except allowed ones but if they try like google or facebook etc using https they get access and the reason i cant block port 443 because few of the allowed domains only work on port 443 so i need to keep that open, jsut need a way to filter https domains as well

marcelloc

@xbipin:

currently on squid2 clients r blocked http connections to all domains except allowed ones but if they try like google or facebook etc using https they get access and the reason i cant block port 443 because few of the allowed domains only work on port 443 so i need to keep that open, jsut need a way to filter https domains as well

You can use squid3-dev to transparent filter ssl and whitelist domains you allow.
sites/domains in whitelist does not get intercepted by ssl.
all other non allowed domains will alert certificate and then show squidguard block page.

xbipin

but then i got 2 groups on lan clients, one with limited access and the second with full access to the internet and squidguard checks which group client belongs to and then does the appropriate thing, the unrestricted clients just are allowed everything in which case their traffic need not be intercepted, only the ones that are restricted should be

xbipin

@marcelloc:

@xbipin:

currently on squid2 clients r blocked http connections to all domains except allowed ones but if they try like google or facebook etc using https they get access and the reason i cant block port 443 because few of the allowed domains only work on port 443 so i need to keep that open, jsut need a way to filter https domains as well

You can use squid3-dev to transparent filter ssl and whitelist domains you allow.
sites/domains in whitelist does not get intercepted by ssl.
all other non allowed domains will alert certificate and then show squidguard block page.

can u elaborate on how the CA etc stuff needs to be configured and what is to be exported to client PC?

correct me if im wrong

goto CAs section and generate a new CA as create an internal CA (will any settings do or some specific settings only)
once done export that CA and use in client

marcelloc

@xbipin:

correct me if im wrong

goto CAs section and generate a new CA as create an internal CA (will any settings do or some specific settings only)

Yes, internal CA or import existing CA used on you AD or something else

@xbipin:

once done export that CA and use in client

yes, Download CA CRT file and then import on internet explorer and firefox as a trusted ca.

xbipin

i installed squid3-dev and imported those library files manually and squid started fine, then i tried installing squidguard and it would always end up in errors and crashes and crash dumps generated so ir ebooted the box and then it totally broke and i kept getting the below errors, had to factory reset and restore my old config, can u check whats the issue

Fatal error: Cannot use string offset as an array in /usr/local/pkg/squid.inc on
 line 1977

Fatal error: Cannot use string offset as an array in /usr/local/pkg/squidguard.i
nc on line 1009

marcelloc

If you are on 2.0.3, try this squid 3.3.5 from my repo.

amd64
http://e-sac.siteseguro.ws/packages/amd64/8/All/squid-3.3.5.tbz

i386
http://e-sac.siteseguro.ws/packages/8/All/squid-3.3.5.tbz

always after squidguard install, you need to reinstall squid3/squid3-dev

xbipin

im on 2.1 RC0

marcelloc

@xbipin:

im on 2.1 RC0

I'm waiting this freebsd port update to ask another pbi compilation.

Current squid 3.3.4 squid version without specific patch crashes ssl negotiation on open ssl version used on 2.1 RC0

3.3.4 patched and 3.3.5 does not has this bug.

ncolunga

I add 0,25 BTC to the bounty.

marcelloc

@ncolunga:

I add 0,25 BTC to the bounty.

Thanks! ;D

You can send it to my paypal account marcellocoutinho@gmail.com

xbipin

any news on when the port will be compiled with the necessary lib files and created into a pfsense downloadable package?

marcelloc

@xbipin:

any news on when the port will be compiled with the necessary lib files and created into a pfsense downloadable package?

~~Squid 3.3.5 is still pending on freebsd ports. I've sent the updated but it was forwarded to freebsd package maintainer.

After it is on freebsd ports, I'll ask another compile and maybe remove sasl auth to do not require libs that is not on pfsense install.~~

EDIT

It was updated yesterday. :)

I'll ask another compile run.

davidjtsteele

Apparently, it may of been pulled off of the site, you must have transparental rights in order to get the ssl filter.

marcelloc

squid 3.3.5 is on official repo.

Missing libs are still missing and on 2.0.3 you need to enable ipv6 to squid be able to listen on it's ports.

shawniverson

$100 from here. Looking for a new content filtering solution and ssl filtering is a must.

vreid473

I want to make sure I'm understanding how the ssl filtering works with squid + squidguard. Here's what I've understood so far. Please correct me if I have some of the points incorrect. In particular, I am unclear about my numbers 2, 3, and the level of intrusiveness of https decryption in 4.

1. You need squid3 + squidguard + some additional manual packages to install the software framework to get ssl filtering working
2. You need a real ssl certificate (versus self-signed) to install on the pfsense host to be able to get ssl filtering functionality to work correctly without throwing error messages on the client browsers??
3. Do you also need to install the ssl certificate in #2 onto each host that will be filtered onto each client browser as a trusted certificate??
4. Once the items above have been configured, then squid + squidquard will decrypt the https traffic, scan the contents for url + any content that may need a rewrite, and then block or allow the traffic and/or make the required rewrites. In either case I am understanding that all of the https content gets decrypted, not just the destination data/header.

Thanks