Security hardening¶

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 project.

Configuring Compute to use trusted compute pools

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

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

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

   [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.

3. 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:

Specifying trusted flavors

1. Flavors can be designated as trusted using the openstack flavor set command. In this example, the m1.tiny flavor is being set as trusted:

   $ openstack flavor set --property trusted_host=trusted m1.tiny
   

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

   $ openstack server create --flavor m1.tiny \
     --key-name myKeypairName --image myImageID newInstanceName
   

Encrypt Compute metadata traffic¶

Enabling SSL encryption

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

1. Enable the HTTPS protocol.

   nova_metadata_protocol = https
   

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

   nova_metadata_insecure = False
   

3. Specify the path to the client certificate.

   nova_client_cert = PATH_TO_CERT
   

4. Specify the path to the private key.

   nova_client_priv_key = PATH_TO_KEY