mirror of
https://github.com/opnsense/docs
synced 2024-10-30 21:20:20 +00:00
182 lines
6.9 KiB
ReStructuredText
182 lines
6.9 KiB
ReStructuredText
=======================
|
|
Setup Transparent Proxy
|
|
=======================
|
|
OPNsense offers a powerful proxy that can be used in combination with category
|
|
based web filtering and any ICAP capable anti virus/malware engine. The proxy
|
|
can be configured to run in transparent mode, this mean the clients browser does
|
|
not have to be configured for the web proxy, but all traffic is diverted to the
|
|
proxy automatically by utilizing Network Address Translation.
|
|
|
|
In this How To, we will explain the basic http as well as https (ssl bump) transparent
|
|
proxy modes.
|
|
|
|
.. Warning::
|
|
The Transparent SSL/HTTPS proxy mode uses a technique also called man-in-the-middle,
|
|
only configure and use this if your know what you are doing. When configured wrong
|
|
you may end up in lessing your security defenses significantly instead of enhancing
|
|
them. Using a transparent https proxy can be a dangerous practice and may not be
|
|
allowed by the services you use, for instance e-banking.
|
|
|
|
Step 1 - Basic Proxy Setup
|
|
--------------------------
|
|
To setup the transparent mode(s) a functional basic proxy setup is required.
|
|
For basic configuration please refer to :doc:`cachingproxy`.
|
|
|
|
Step 2 - Transparent HTTP
|
|
--------------------------------
|
|
Go to **Services->Proxy->Administration**
|
|
|
|
Then select **General Forward Settings** under the **Forward Proxy Tab**.
|
|
|
|
Select **Enable Transparent HTTP proxy**
|
|
And Click **Apply**.
|
|
|
|
Step 3 - NAT/Firewall Rule
|
|
---------------------------------
|
|
A simple way to add the NAT/Firewall Rule is to click on the **(i)** icon on the
|
|
left of the **Enable Transparent HTTP proxy** option and click on **add a new firewall rule**.
|
|
|
|
.. image:: images/screenshot_enable_transparent_http.png
|
|
:scale: 100%
|
|
|
|
**For reference, these are the default settings:**
|
|
|
|
============================ =================================
|
|
**Interface** LAN
|
|
**Protocol** TCP
|
|
**Source** LAN net
|
|
**Source port range** any - any
|
|
**Destination** any
|
|
**Destination port range** HTTP - HTTP
|
|
**Redirect target IP** 127.0.0.1
|
|
**Redirect target port** other/3128
|
|
**Description** redirect traffic to proxy
|
|
**NAT reflection** Enable
|
|
**Filter rule association** Add associated filter rule
|
|
============================ =================================
|
|
|
|
The defaults should be alright, just press **Save** and **Apply Changes**.
|
|
|
|
|
|
Step 4 - CA for Transparent SSL
|
|
--------------------------------------
|
|
Before we can setup transparent SSL/HTTPS proxy we need to create a Certificate
|
|
Authority. Go to **System->Trust->Authorities** or use the search box to get there
|
|
fast.
|
|
|
|
.. image:: images/search_ca.png
|
|
:scale: 100%
|
|
|
|
Click on **add or import ca** in the upper right corner of the screen to create
|
|
a new CA.
|
|
|
|
For our example we use the following data:
|
|
|
|
======================== ===========================================
|
|
**Descriptive name** OPNsense-SSL
|
|
**Method** Create an internal Certificate Authority
|
|
**Key length (bits)** 2048
|
|
**Digest Algorithm** SHA256
|
|
**Lifetime (days)** 356
|
|
**Country Code** NL (Netherlands)
|
|
**State or Province** Zuid Holland
|
|
**City** Middelharnis
|
|
**Organization** OPNsense
|
|
**Email Address** spam@opnsense.org
|
|
**Common Name** opnsense-ssl-ca
|
|
======================== ===========================================
|
|
|
|
**Save**
|
|
|
|
Step 5 - Transparent SSL
|
|
-------------------------------------
|
|
Go to **Services->Proxy->Administration**
|
|
Then select **General Forward Settings** under the **Forward Proxy Tab**.
|
|
|
|
Select **Enable SSL mode** and set **CA to use** to the CA you have just created.
|
|
Then Click **Apply**.
|
|
|
|
Step 6 - Configure No SSL Bump
|
|
------------------------------
|
|
This step is very important and requires careful consideration!
|
|
To make sure that known sites are not bumped and keep their original security layer
|
|
intact, one needs to add those including all subdomain to the **SSL no bump sites**
|
|
field.
|
|
|
|
To enter a new item type in the field and hit enter to accept. start with a . (dot)
|
|
to add all subdomains as well. Example: To add all of paypal.com , type .paypal.com
|
|
and hit enter.
|
|
|
|
.. Note::
|
|
Make sure that all banking sites and sites that you provide personal or login
|
|
information for are added to this field. If you are not sure what to add, please
|
|
reconsider using transparent SSL as its clearly not intended for you!
|
|
|
|
|
|
|
|
|
|
Step 7 - SSL NAT/Firewall Rule
|
|
-------------------------------------
|
|
A simple way to add the NAT/Firewall Rule is to click on the **(i)** icon on the
|
|
left of the **Enable SSL mode** option and click on **add a new firewall rule**.
|
|
|
|
.. image:: images/screenshot_enable_transparent_http.png
|
|
:scale: 100%
|
|
|
|
**For reference, these are the default settings:**
|
|
|
|
============================ =================================
|
|
**Interface** LAN
|
|
**Protocol** TCP
|
|
**Source** LAN net
|
|
**Source port range** any - any
|
|
**Destination** any
|
|
**Destination port range** HTTPS - HTTPS
|
|
**Redirect target IP** 127.0.0.1
|
|
**Redirect target port** other/3129
|
|
**Description** redirect traffic to proxy
|
|
**NAT reflection** Enable
|
|
**Filter rule association** Add associated filter rule
|
|
============================ =================================
|
|
|
|
The defaults should be alright, just press **Save** and **Apply Changes**.
|
|
|
|
Step 8 - Configure OS/Browser
|
|
-----------------------------
|
|
Since the CA is not trusted by your browser, you will get a message about this
|
|
for each page you visit. To solve this you can import the Key into your OS and
|
|
set as trusted. To export the Key go to **System->Trust->Authorities** and click
|
|
on the icon to export the CA certificate. Of course one may choose to accept the
|
|
certificate for each page manually, but for some pages that may not work well unless
|
|
not bumped.
|
|
|
|
.. image:: images/export_CA_cert.png
|
|
:scale: 100%
|
|
|
|
Import and change trust settings on your favorite OS. Per example on OSX it looks
|
|
like this:
|
|
|
|
.. image:: images/Trust_Settings_OSX.png
|
|
:scale: 100%
|
|
|
|
.. Warning::
|
|
Again be very careful with this as your system will accept any page signed with
|
|
this CA certificate. As long as no-one gains access to the private key that
|
|
is no problem, but if any one can get a get a hold of it then all traffic
|
|
can be decrypted except those in the *do not bump* list. You have been warned!
|
|
|
|
.. Note::
|
|
On Android devices, you may get notified about the device being unable to access
|
|
the internet. This happens because the certificates are pinned to protect the
|
|
connection against man in the middle attacks otherwise trusted certificates.
|
|
If you want to make the connection work again, you have to whitelist the following
|
|
Google domains in your "No Bump Hosts" settings.
|
|
|
|
* Your local Google domain (for example: google.at for Austria, google.de for Germany, …)
|
|
* .google.com
|
|
* .googleapis.com
|
|
* .gstatic.com
|
|
* .1e100.net
|
|
|
|
**DONE**
|