OpenCTI
=========

.. image:: /applications/opencti.png
   :class: align-center

Presentation
------------

`OpenCTI <https://filigran.io/solutions/open-cti/>`__ is an open source platform allowing organizations to manage their cyber threat intelligence knowledge and observables.

OpenCTI allows SSO via the SAML or OIDC protocols.


Configuring OpenCTI (SAML)
--------------------------

Prerequisites
~~~~~~~~~~~~~

First, generate a key/certificate pair for OpenCTI ::

    openssl req -x509 -newkey rsa:4096 -keyout octi-saml-key.pem -out octi-saml-cert.pem -sha256 -days 3650 -noenc


Then, download the LemonLDAP::NG SAML metadata at https://auth.example.com/saml/metadata/idp

In this certificate, extract the ``ds:X509Certificate`` element inside the ``KeyDescriptor use="signing"`` element, and remove all spaces, you will get a long Base64 string that looks like ::

    # On a single line, with no spaces
    MIIFazCCA1OgAwIBAgIUDuUn+nT550rK0Qsej28PlQpZoFkwDQYJKoZIhvcN....

Do the same with ``octi-saml-key.pem`` in order to get a long Base64 string representing the OpenCTI signing key.

Regular installation
~~~~~~~~~~~~~~~~~~~~

In your OpenCTI configuration ::

    "saml": {
    "identifier": "saml",
    "strategy": "SamlStrategy",
    "config": {
        "issuer": "opencti",
        "entry_point": "https://auth.example.com/saml/singleSignOn",
        "saml_callback_url": "https://opencti.example.com/auth/saml/callback",
        "private_key": "MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwg...",
        "cert": "MIICmzCCAYMCBgF2Qt3X1zANBgkqhkiG9w0BAQsFADARMQ8w...",
        "roles_management": {
          "role_attributes": ["groups"],
          "roles_mapping": ["my_lemonldap_group:Administrator"]
        }
    }

* ``private_key`` must contain the concatenated content of ``octi-saml-key.pem``
* ``cert`` must contain the concatenated content of the LemonLDAP::NG signing certificate, from SAML metadata
* The ``roles_management`` element is only useful if you want to automatically affect roles to your LemonLDAP::NG users depending on their groups.

Docker
~~~~~~

In a docker setup, add the following environment variables ::

      - PROVIDERS__SAML__STRATEGY=SamlStrategy
      - "PROVIDERS__SAML__CONFIG__LABEL=Login with SAML"
      - PROVIDERS__SAML__CONFIG__ISSUER=opencti
      - PROVIDERS__SAML__CONFIG__ENTRY_POINT=https://auth.example.com/saml/singleSignOn
      - PROVIDERS__SAML__CONFIG__SAML_CALLBACK_URL=https://opencti.example.com/auth/saml/callback
      - PROVIDERS__SAML__CONFIG__CERT=MIICmzCCAYMCBgF2Qt3X1zANBgkqhkiG9w0BAQsFADARMQ8w...
      - PROVIDERS__SAML__CONFIG__PRIVATE_KEY=MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwg...
      - "PROVIDERS__SAML__CONFIG__ROLES_MANAGEMENT__ROLE_ATTRIBUTES=[\"groups\"]"
      - "PROVIDERS__SAML__CONFIG__ROLES_MANAGEMENT__ROLES_MAPPING=[\"my_lemonldap_group:Administrator\"]"

* ``PRIVATE_KEY`` must contain the concatenated content of ``octi-saml-key.pem``
* ``CERT`` must contain the concatenated content of the LemonLDAP::NG signing certificate, from SAML metadata
* The ``ROLES_MANAGEMENT`` variables are only useful if you want to automatically affect roles to your LemonLDAP::NG users depending on their groups.


Configuring LemonLDAP (SAML)
----------------------------

Generating OpenCTI metadata
~~~~~~~~~~~~~~~~~~~~~~~~~~~

Edit the following template to create the metadata for OpenCTI ::

    <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
    <EntityDescriptor
     entityID="opencti"
     xmlns="urn:oasis:names:tc:SAML:2.0:metadata">
     <SPSSODescriptor
       AuthnRequestsSigned="true"
       WantAssertionsSigned="true"
       protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol">
       <KeyDescriptor use="signing"><ds:KeyInfo xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:X509Data><ds:X509Certificate>
       ###paste the content of octi-saml-cert.pem here, without the BEGIN and END line###
       </ds:X509Certificate></ds:X509Data></ds:KeyInfo></KeyDescriptor>
       <AssertionConsumerService
         index="0"
         isDefault="true"
         Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST"
         Location="https://opencti.example.com/auth/saml/callback" />
     </SPSSODescriptor>

    </EntityDescriptor>

Don't forget to replace the ``Location=`` attribute and the content of ``X509Certificate``.

Adding OpenCTI::NG to LemonLDAP configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Add a new :ref:`new SAML Service Provider to the LemonLDAP::NG configuration<samlidp-register-sp>`
with the following parameters:

* **Metadata**
   * Copy the Metadata generated at the previous step
* **Exported Attributes**
   * variable name: ``groups``
   * attribute name: ``groups``


OIDC Interconnection
--------------------

This section describe the OpenID Connect configuration

Configure OpenCTI (OIDC)
~~~~~~~~~~~~~~~~~~~~~~~~

Here is the basic configuration for a docker installation

Define and replace ``<clientid>`` and ``<clientsecret>``, and also adapt issuer and redirect uri:

.. code-block::

    - PROVIDERS__OPENID__STRATEGY=OpenIDConnectStrategy
    - "PROVIDERS__OPENID__CONFIG__LABEL=Login with OpenID"
    - PROVIDERS__OPENID__CONFIG__ISSUER=https://auth.example.com
    - PROVIDERS__OPENID__CONFIG__CLIENT_ID=<clientid>
    - PROVIDERS__OPENID__CONFIG__CLIENT_SECRET=<clientsecret>
    - "PROVIDERS__OPENID__CONFIG__REDIRECT_URIS=[\"https://opencti.mydomain.com/auth/oic/callback\"]"

For an advanced usage, you can also map lemonldap groups to openCTI groups with these paramters:

.. code-block::

    - "PROVIDERS__OPENID__CONFIG__GROUPS_MANAGEMENT__GROUPS_SCOPE=groups"
    - "PROVIDERS__OPENID__CONFIG__GROUPS_MANAGEMENT__GROUPS_PATH=[\"groups\", \"realm_access.groups\", \"resource_access.account.groups\"]"
    - "PROVIDERS__OPENID__CONFIG__GROUPS_MANAGEMENT__GROUPS_MAPPING=[\"OpenID_Group_1:OpenCTI_Group_1\", \"OpenID_Group_2:OpenCTI_Group_2\", ...]"


Configure LemonLDAP (OIDC)
~~~~~~~~~~~~~~~~~~~~~~~~~~

Configure LemonLDAP as an :doc:`OpenID Connect provider <../idpopenidconnect>`.

As describe in documentation link above, also define a new Relying Party in LL::NG.

Take care to configure at least these parameters:

* ``Public client``: disabled
* ``Client ID``: client id defined in previous section
* ``Client secret``: client secret defined in previous section
* ``Allowed redirection addresses for login``: redirect uri defined in previous section
* ``Security -> ID Token signature algorithm``: make sure you select **RS256**, as HS512 is not supported in OpenCTI
* ``Advanced -> User attribute``: take care to use the user unique identifier defined in OpenCTI, usually ``mail``

Advanced usage, for group mapping:

* ``Exported attributes (claims)``: add claim ``groups -> groups``
* ``Options -> Scope``: add scope ``groups -> groups``


