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129 lines
3.4 KiB
ReStructuredText
129 lines
3.4 KiB
ReStructuredText
==========================
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IPS Block SSL certificates
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==========================
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This tutorial explains how to setup the IPS system to block ssl certificates based on their
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SHA1 fingerprint.
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-------------
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Prerequisites
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-------------
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* Always upgrade to latest release first.
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See :doc:`/manual/install` and/or upgrade to latest release:
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:menuselection:`System --> Firmware --> Fetch updates`.
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.. image:: images/firmware.png
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:width: 100%
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* Minimum Advisable Memory is 2 Gigabyte and sufficient free disk space for
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logging (>10 GB advisable).
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* Disable all Hardware Offloading
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Under **Interface-Settings**
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.. image:: images/disable_offloading.png
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:width: 100%
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.. warning::
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After applying you need to reboot OPNsense otherwise offloading may not
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completely be disabled and IPS mode will not function.
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To start go to :menuselection:`Services --> Intrusion Detection`
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|ids_menu|
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------------
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User defined
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------------
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Select the tab **User defined**.
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|ids_tabs_user|
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-----------------
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Create a new Rule
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-----------------
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Select |add| to add a new rule.
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Get fingerprint of website
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--------------------------
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It is relatively easy to find out the SSL fingerprint of a website.
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For demonstration we will block facebook and use Firefox to determine the fingerprint.
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Open your browser and go to https://facebook.com when loaded click on the lock
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next to the address : |lock|.
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Now you will see something similar to:
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.. image:: images/facebook_click.png
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:width: 100%
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Click on the arrow ( **>** ) and then Select **More Information**
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Now open the certificate details and you will see something that looks like this:
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.. image:: images/certificate.png
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:width: 100%
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Copy the SHA1 certificate fingerprint (A0:4E:AF:B3:48:C2:6B:15:A8:C1:AA:87:A3:33:CA:A3:CD:EE:C9:C9).
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Paste this into the new rule:
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.. image:: images/ips_rule_details.png
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:width: 100%
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Select the Action (Alert or Drop):
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.. image:: images/ips_action.png
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:width: 100%
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Add a description:
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.. image:: images/ips_description.png
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:width: 100%
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And click **Save changes** |save|
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---------------------------------------
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Enable Intrusion Detection & Prevention
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---------------------------------------
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To enable IDS/IPS just go to :menuselection:`Services --> Intrusion Detection` and select **enabled & IPS mode**.
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Make sure you have selected the right interface for the intrusion detection system too run on. For our example
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we will use the WAN interface, as that will most likely be you connection with the public Internet.
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.. image:: images/idps.png
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:width: 100%
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-------------------
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Apply configuration
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-------------------
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First apply the configuration by pressing the **Apply** button at the bottom of
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the form.
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.. image:: images/applybtn.png
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----------------------------
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Clear Browser Cache and test
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----------------------------
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Since your browser has cached the ssl certificate you will need to clear your
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cache first. After that you can test and will see the following in **Alerts**:
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.. image:: images/ips_facebook_alert.png
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:width: 100%
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.. Note::
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If the browser has cached the certificate no SSL certificate exchange will be
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done and the website will not be blocked.
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.. |save| image:: images/ips_save.png
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.. |ids_menu| image:: images/ids_menu.png
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.. |ids_tabs_user| image:: images/ids_tabs_user.png
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.. |add| image:: images/ids_tabs_user_add.png
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.. |lock| image:: images/facebook_lock.png
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