.. _section-compute-security:

==================
Security hardening
==================

OpenStack Compute can be integrated with various third-party
technologies to increase security. For more information, see the
`OpenStack Security Guide <http://docs.openstack.org/sec/>`_.

Trusted compute pools
~~~~~~~~~~~~~~~~~~~~~

Administrators can designate a group of compute hosts as trusted using
trusted compute pools. The trusted hosts use hardware-based security
features, such as the Intel Trusted Execution Technology (TXT), to
provide an additional level of security. Combined with an external
stand-alone, web-based remote attestation server, cloud providers can
ensure that the compute node runs only software with verified
measurements and can ensure a secure cloud stack.

Trusted compute pools provide the ability for cloud subscribers to
request services run only on verified compute nodes.

The remote attestation server performs node verification like this:

1. Compute nodes boot with Intel TXT technology enabled.

2. The compute node BIOS, hypervisor, and operating system are measured.

3. When the attestation server challenges the compute node, the measured
   data is sent to the attestation server.

4. The attestation server verifies the measurements against a known good
   database to determine node trustworthiness.

A description of how to set up an attestation service is beyond the
scope of this document. For an open source project that you can use to
implement an attestation service, see the `Open
Attestation <https://github.com/OpenAttestation/OpenAttestation>`__
project.


.. figure:: figures/OpenStackTrustedComputePool1.png

   **Configuring Compute to use trusted compute pools**

#. Enable scheduling support for trusted compute pools by adding these
   lines to the ``DEFAULT`` section of the ``/etc/nova/nova.conf`` file:

   .. code-block:: ini

      [DEFAULT]
      compute_scheduler_driver=nova.scheduler.filter_scheduler.FilterScheduler
      scheduler_available_filters=nova.scheduler.filters.all_filters
      scheduler_default_filters=AvailabilityZoneFilter,RamFilter,ComputeFilter,TrustedFilter

#. Specify the connection information for your attestation service by
   adding these lines to the ``trusted_computing`` section of the
   ``/etc/nova/nova.conf`` file:

   .. code-block:: ini

      [trusted_computing]
      attestation_server = 10.1.71.206
      attestation_port = 8443
      # If using OAT v2.0 after, use this port:
      # attestation_port = 8181
      attestation_server_ca_file = /etc/nova/ssl.10.1.71.206.crt
      # If using OAT v1.5, use this api_url:
      attestation_api_url = /AttestationService/resources
      # If using OAT pre-v1.5, use this api_url:
      # attestation_api_url = /OpenAttestationWebServices/V1.0
      attestation_auth_blob = i-am-openstack

   In this example:

   server
     Host name or IP address of the host that runs the attestation
     service

   port
     HTTPS port for the attestation service

   server_ca_file
     Certificate file used to verify the attestation server's identity

   api_url
     The attestation service's URL path

   auth_blob
     An authentication blob, required by the attestation service.

#. Save the file, and restart the ``nova-compute`` and ``nova-scheduler``
   service to pick up the changes.

To customize the trusted compute pools, use these configuration option
settings:

.. list-table:: **Description of trusted computing configuration options**
   :header-rows: 2

   * - Configuration option = Default value
     - Description
   * - [trusted_computing]
     -
   * - attestation_api_url = /OpenAttestationWebServices/V1.0
     - (StrOpt) Attestation web API URL
   * - attestation_auth_blob = None
     - (StrOpt) Attestation authorization blob - must change
   * - attestation_auth_timeout = 60
     - (IntOpt) Attestation status cache valid period length
   * - attestation_insecure_ssl = False
     - (BoolOpt) Disable SSL cert verification for Attestation service
   * - attestation_port = 8443
     - (StrOpt) Attestation server port
   * - attestation_server = None
     - (StrOpt) Attestation server HTTP
   * - attestation_server_ca_file = None
     - (StrOpt) Attestation server Cert file for Identity verification

**Specifying trusted flavors**

#. Flavors can be designated as trusted using the
   :command:`nova flavor-key set` command. In this example, the ``m1.tiny``
   flavor is being set as trusted:

   .. code-block:: console

      $ nova flavor-key m1.tiny set trust:trusted_host=trusted

#. You can request that your instance is run on a trusted host by
   specifying a trusted flavor when booting the instance:

   .. code-block:: console

      $ nova boot --flavor m1.tiny --key-name myKeypairName --image myImageID newInstanceName


.. figure:: figures/OpenStackTrustedComputePool2.png


Encrypt Compute metadata traffic
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Enabling SSL encryption**

OpenStack supports encrypting Compute metadata traffic with HTTPS.
Enable SSL encryption in the ``metadata_agent.ini`` file.

#. Enable the HTTPS protocol.

   .. code-block:: ini

      nova_metadata_protocol = https

#. Determine whether insecure SSL connections are accepted for Compute
   metadata server requests. The default value is ``False``.

   .. code-block:: ini

      nova_metadata_insecure = False

#. Specify the path to the client certificate.

   .. code-block:: ini

      nova_client_cert = PATH_TO_CERT

#. Specify the path to the private key.

   .. code-block:: ini

      nova_client_priv_key = PATH_TO_KEY