4.3.8 Ensure 'Infrastructure double encryption' for PostgreSQL Database Server is 'Enabled'

Information

Enable encryption at rest for PostgreSQL Databases.

Rationale:

If Double Encryption is enabled, another layer of encryption is implemented at the hardware level before the storage or network level. Information will be encrypted before it is even accessed, preventing both interception of data in motion if the network layer encryption is broken and data at rest in system resources such as memory or processor cache. Encryption will also be in place for any backups taken of the database, so the key will secure access the data in all forms. For the most secure implementation of key based encryption, it is recommended to use a Customer Managed asymmetric RSA 2048 Key in Azure Key Vault.

Impact:

The read and write speeds to the database will be impacted if both default encryption and Infrastructure Encryption are checked, as a secondary form of encryption requires more resource overhead for the cryptography of information. This cost is justified for information security. Customer managed keys are recommended for the most secure implementation, leading to overhead of key management. The key will also need to be backed up in a secure location, as loss of the key will mean loss of the information in the database.

Solution

From Azure Portal
For the creation of a new server;

Go through the normal process of database creation.

On step 2 titled 'Additional settings' ensure that 'Infrastructure double encryption enabled' is 'checked'

Acknowledge that you understand this will impact database performance.

Finish database creation as normal.

On the final 'Review + create' screen, ensure that at the very bottom of the database properties, that 'Infrastructure (Double) encryption' is 'enabled'.

For existing servers;

From Azure Home, click on more services.

Click on Databases

Click on Azure Database for PostgreSQL servers

Select the database by clicking on its name.

Select the second from the left option 'Additional settings'.

Check the box next to 'Infrastructure double encryption enabled'.

From Azure CLI
Creating a New Server with Infrastructure Encryption Enabled
Enter the command as follows;

az postgres server create --resource-group <resourcegroup> --name <servername> --location <location> --admin-user <adminusername> --admin-password <server_admin_password> --sku-name GP_Gen4_2 --version 11 --infrastructure-encryption 'Enabled'

Updating a Server's Configuration

az postgres server configuration set -g <resourcegroup>-s <servername> --infrastructure-encryption <Enabled>

Default Value:

By Default, Double Encryption is disabled.

See Also

https://workbench.cisecurity.org/files/4052