Volume encryption supported by the key manager¶

We recommend the Key management service (barbican) for storing encryption keys used by the OpenStack volume encryption feature. It can be enabled by updating cinder.conf and nova.conf.

Initial configuration¶

Configuration changes need to be made to any nodes running the cinder-volume or nova-compute server.

Steps to update cinder-volume servers:

Edit the /etc/cinder/cinder.conf file to use Key management service as follows:
- Look for the [keymgr] section.
- Enter a new line directly below [keymgr] with the following:
```
api_class = cinder.keymgr.barbican.BarbicanKeyManager
```
  Note
  
  Use a ‘#’ prefix to comment out the line in this section that begins with ‘fixed_key’.
Restart cinder-api.

Update nova-compute servers:

Install the cryptsetup utility.

Set up the Key Manager service by editing /etc/nova/nova.conf.

[keymgr]
api_class = nova.keymgr.barbican.BarbicanKeyManager

Restart nova-compute.

Follow the instructions in the OpenStack Administrator Guide under the heading Create an encrypted volume type or alternatively, see TODO in this manual to do this via the command line.

TODO: Add link to section_create-encrypted-volume-type.

Create an encrypted volume by typing the command:

$ cinder create --name encryptedVolume --volume-type LUKS 1

For alternate instructions and details, including the console output, see the TODO in this document.

TODO: Add link to section_create_volume.

Create an encrypted volume type¶

Block Storage volume type assignment provides scheduling to a specific back-end, and can be used to specify actionable information for a back-end storage device.

This example creates a volume type called LUKS and provides configuration information for the storage system to encrypt or decrypt the volume.

Source your admin credentials:
```
$ . admin-openrc.sh
```

Create the volume type:

$ cinder type-create LUKS
+--------------------------------------+-------+
|                  ID                  |  Name |
+--------------------------------------+-------+
| e64b35a4-a849-4c53-9cc7-2345d3c8fbde | LUKS  |
+--------------------------------------+-------+

Mark the volume type as encrypted and provide the necessary details. Use --control_location to specify where encryption is performed: front-end (default) or back-end.

$ cinder encryption-type-create --cipher aes-xts-plain64 --key_size 512 \
  --control_location front-end LUKS nova.volume.encryptors.luks.LuksEncryptor
+--------------------------------------+-------------------------------------------+-----------------+----------+------------------+
|            Volume Type ID            |                  Provider                 |      Cipher     | Key Size | Control Location |
+--------------------------------------+-------------------------------------------+-----------------+----------+------------------+
| e64b35a4-a849-4c53-9cc7-2345d3c8fbde | nova.volume.encryptors.luks.LuksEncryptor | aes-xts-plain64 |   512    |    front-end     |
+--------------------------------------+-------------------------------------------+-----------------+----------+------------------+

The OpenStack dashboard (horizon) supports creating the encrypted volume type as of the Kilo release.

Create an encrypted volume¶

Use the OpenStack dashboard (horizon), or the cinder command to create volumes just as you normally would. For an encrypted volume, pass the --volume-type LUKS flag, which denotes that the volume will be of encrypted type LUKS. If that argument is left out, the default volume type, unencrypted, is used.

Source your admin credentials:
```
$ . admin-openrc.sh
```

Create an unencrypted 1 GB test volume:

$ cinder create --display-name 'unencrypted volume' 1
+--------------------------------+--------------------------------------+
|            Property            |                Value                 |
+--------------------------------+--------------------------------------+
|          attachments           |                  []                  |
|       availability_zone        |                 nova                 |
|            bootable            |                false                 |
|           created_at           |      2014-08-10T01:24:03.000000      |
|          description           |                 None                 |
|           encrypted            |                False                 |
|               id               | 081700fd-2357-44ff-860d-2cd78ad9c568 |
|            metadata            |                  {}                  |
|              name              |          unencrypted volume          |
|     os-vol-host-attr:host      |              controller              |
| os-vol-mig-status-attr:migstat |                 None                 |
| os-vol-mig-status-attr:name_id |                 None                 |
|  os-vol-tenant-attr:tenant_id  |   08fdea76c760475f82087a45dbe94918   |
|              size              |                  1                   |
|          snapshot_id           |                 None                 |
|          source_volid          |                 None                 |
|             status             |               creating               |
|            user_id             |   7cbc6b58b372439e8f70e2a9103f1332   |
|          volume_type           |                 None                 |
+--------------------------------+--------------------------------------+

Create an encrypted 1 GB test volume:

$ cinder create --display-name 'encrypted volume' --volume-type LUKS 1
+--------------------------------+--------------------------------------+
|            Property            |                Value                 |
+--------------------------------+--------------------------------------+
|          attachments           |                  []                  |
|       availability_zone        |                 nova                 |
|            bootable            |                false                 |
|           created_at           |      2014-08-10T01:24:24.000000      |
|          description           |                 None                 |
|           encrypted            |                 True                 |
|               id               | 86060306-6f43-4c92-9ab8-ddcd83acd973 |
|            metadata            |                  {}                  |
|              name              |           encrypted volume           |
|     os-vol-host-attr:host      |              controller              |
| os-vol-mig-status-attr:migstat |                 None                 |
| os-vol-mig-status-attr:name_id |                 None                 |
|  os-vol-tenant-attr:tenant_id  |   08fdea76c760475f82087a45dbe94918   |
|              size              |                  1                   |
|          snapshot_id           |                 None                 |
|          source_volid          |                 None                 |
|             status             |               creating               |
|            user_id             |   7cbc6b58b372439e8f70e2a9103f1332   |
|          volume_type           |                 LUKS                 |
+--------------------------------+--------------------------------------+

Notice the encrypted parameter; it will show True or False. The option volume_type is also shown for easy review.

Note

Due to the issue that some of the volume drivers do not set encrypted flag, attaching of encrypted volumes to a virtual guest will fail, because OpenStack Compute service will not run encryption providers.

Testing volume encryption¶

This is a simple test scenario to help validate your encryption. It assumes an LVM based Block Storage server.

Perform these steps after completing the volume encryption setup and creating the volume-type for LUKS as described in the preceding sections.

Create a VM:

$ nova boot --flavor m1.tiny --image cirros-0.3.1-x86_64-disk vm-test

Create two volumes, one encrypted and one not encrypted then attach them to your VM:

$ cinder create --display-name 'unencrypted volume' 1
$ cinder create --display-name 'encrypted volume' --volume-type LUKS 1
$ cinder list
+--------------------------------------+-----------+--------------------+------+-------------+----------+-------------+
|                  ID                  |   Status  |        Name        | Size | Volume Type | Bootable | Attached to |
+--------------------------------------+-----------+--------------------+------+-------------+----------+-------------+
| 64b48a79-5686-4542-9b52-d649b51c10a2 | available | unencrypted volume |  1   |     None    |  false   |             |
| db50b71c-bf97-47cb-a5cf-b4b43a0edab6 | available |  encrypted volume  |  1   |     LUKS    |  false   |             |
+--------------------------------------+-----------+--------------------+------+-------------+----------+-------------+
$ nova volume-attach vm-test 64b48a79-5686-4542-9b52-d649b51c10a2 /dev/vdb
$ nova volume-attach vm-test db50b71c-bf97-47cb-a5cf-b4b43a0edab6 /dev/vdc

On the VM, send some text to the newly attached volumes and synchronize them:

# echo "Hello, world (unencrypted /dev/vdb)" >> /dev/vdb
# echo "Hello, world (encrypted /dev/vdc)" >> /dev/vdc
# sync && sleep 2
# sync && sleep 2

On the system hosting cinder volume services, synchronize to flush the I/O cache then test to see if your strings can be found:

# sync && sleep 2
# sync && sleep 2
# strings /dev/stack-volumes/volume-* | grep "Hello"
Hello, world (unencrypted /dev/vdb)

In the above example you see that the search returns the string written to the unencrypted volume, but not the encrypted one.