Setting up Local Encryption Keys

Use dsetool createsystemkey to generate local encryption/decryption key files.

To change an encryption key, see Rekeying existing data.

Setting up local encryption keys for production environments

After installing DSE, create a local encryption key file, distribute it to the same location on all nodes in the cluster, and update the dse.yaml system_key_directory and config_encryption_key_name properties.

The location of the dse.yaml file depends on the type of installation:

Package installations: /etc/dse/dse.yaml
Tarball installations: <installation_location>/resources/dse/conf/dse.yaml

To change an encryption key, see Rekeying existing data.

Prerequisites

To ensure support for all encryption algorithms, enable JCE.

Starting in JDK 8u161, JCE Unlimited is enabled by default. Refer to the Release Notes for JDK 8u161.

Procedure

If the directory does not exist, create the /conf directory based on your DataStax Enterprise (DSE) installation type:
- Package installation: /etc/dse/conf
- Tarball installation: <installation_location>/resources/dse/conf
Configure the file name and the location of the encryption key in the dse.yaml file:
1. Set system_key_directory property to the path where you want to store the encryption keys.
  system_key_directory: /etc/dse/conf
2. Change the directory owner to the DSE account and ensure that the DSE account has read/write permissions.
3. Set the config_encryption_key_name to the <key_name>. The default name is system_key.
  config_encryption_key_name: system_key
  Encryption key files can have any valid Unix name.
Go to the system_key_directory and then create an encryption key using the dsetool createsystemkey command:

For example:
```
cd /etc/dse/conf
```
```
dsetool createsystemkey 'AES/ECB/PKCS5Padding' 128 <key_name>
```
Where <key_name> is the name of the key file to create. If no file name is specified, the key file is named system_key.

Encryption key files can have any valid Unix name.

DSE supports the following JCE cipher algorithms and corresponding length:
- cipher_algorithm[/mode/padding]
  
  DSE supports the following JCE cipher algorithms:
  - AES/CBC/PKCS5Padding (valid with length 128, 192, or 256).
  - AES/ECB/PKCS5Padding (valid with length 128, 192, or 256)
  - DES/CBC/PKCS5Padding (valid with length 56)
  - DESede/CBC/PKCS5Padding (valid with length 112 or 168)
  - Blowfish/CBC/PKCS5Padding (valid with length 32-448)
  - RC2/CBC/PKCS5Padding (valid with length 40-128) Default value: AES/CBC/PKCS5Padding (with length 128).
    
    If config_encryption_active is set to true in dse.yaml, a warning is generated, but the system key still successfully generates.
Copy the key file to all other nodes in the cluster. Put keys on all nodes in the same directory.
Update the system_key_directory and config_encryption_key_name in dse.yaml.

dsetool reads current values from the dse.yaml. A restart is not required in order to continue setting up encryption.
Ensure that the DSE account owns the key files and has read/write access on them. If necessary, change the ownership of the file to the DSE user.
```
chown cassandra /etc/dse/conf/system_key
```

Setting up local encryption keys to embed in installation package for development environments

You can create a local encryption or decryption key file that can be embedded in a distribution (tarball). In development environments this distribution package can then be used by other users. This strategy is especially helpful when using scripts with IT automation tools such as Ansible.

The current user must have write permission to the directory where you want to generate the key files.

Procedure

Specify the key file output directory when you create the encryption key with the dsetool createsystemkey command:

For example:
```
dsetool createsystemkey 'AES/ECB/PKCS5Padding' 128 -d /home/jane/keys
```
Result: A key file /home/jane/keys/system_key is created.
In the distribution tarball, create a directory for the system key file. Use the default location (/etc/dse/conf) or add a new location.
Locate the dse.yaml configuration file. The location of this file depends on the type of installation:
- Package installations: /etc/dse/dse.yaml
- Tarball installations: <installation_location>/resources/dse/conf/dse.yaml
If you used a new location, then update the system_key_directory property in dse.yaml as appropriate.