Enable transparent data encryption on Azure Arc-enabled SQL Managed Instance

This article describes how to enable transparent data encryption on a database created in an Azure Arc-enabled SQL Managed Instance. In this article, the term managed instance refers to a deployment of Azure Arc-enabled SQL Managed Instance.

Prerequisites

Before you proceed with this article, you must have an Azure Arc-enabled SQL Managed Instance resource created and connect to it.

Turn on transparent data encryption on a database in the managed instance

Turning on transparent data encryption in the managed instance follows the same steps as SQL Server on-premises. Follow the steps described in SQL Server's transparent data encryption guide.

After you create the necessary credentials, back up any newly created credentials.

Back up a transparent data encryption credential

When you back up credentials from the managed instance, the credentials are stored within the container. To store credentials on a persistent volume, specify the mount path in the container. For example, var/opt/mssql/data. The following example backs up a certificate from the managed instance:

Note

If the kubectl cp command is run from Windows, the command may fail when using absolute Windows paths. Use relative paths or the commands specified below.

  1. Back up the certificate from the container to /var/opt/mssql/data.

    USE master;
    GO
    
    BACKUP CERTIFICATE <cert-name> TO FILE = '<cert-path>'
    WITH PRIVATE KEY ( FILE = '<private-key-path>',
    ENCRYPTION BY PASSWORD = '<UseStrongPasswordHere>');
    

    Example:

    USE master;
    GO
    
    BACKUP CERTIFICATE MyServerCert TO FILE = '/var/opt/mssql/data/servercert.crt'
    WITH PRIVATE KEY ( FILE = '/var/opt/mssql/data/servercert.key',
    ENCRYPTION BY PASSWORD = '<UseStrongPasswordHere>');
    
  2. Copy the certificate from the container to your file system.

kubectl exec -n <namespace> -c arc-sqlmi <pod-name> -- cat <pod-certificate-path> > <local-certificate-path>

Example:

kubectl exec -n arc-ns -c arc-sqlmi sql-0 -- cat /var/opt/mssql/data/servercert.crt > $HOME\sqlcerts\servercert.crt
  1. Copy the private key from the container to your file system.
 kubectl exec -n <namespace> -c arc-sqlmi <pod-name> -- cat <pod-private-key-path> > <local-private-key-path>

Example:

kubectl exec -n arc-ns -c arc-sqlmi sql-0 -- cat /var/opt/mssql/data/servercert.key > $HOME\sqlcerts\servercert.key
  1. Delete the certificate and private key from the container.

    kubectl exec -it --namespace <namespace> --container arc-sqlmi <pod-name> -- bash -c "rm <certificate-path> <private-key-path>
    

    Example:

    kubectl exec -it --namespace arc-ns --container arc-sqlmi sql-0 -- bash -c "rm /var/opt/mssql/data/servercert.crt /var/opt/mssql/data/servercert.key"
    

Restore a transparent data encryption credential to a managed instance

Similar to above, to restore the credentials, copy them into the container and run the corresponding T-SQL afterwards.

Note

If the kubectl cp command is run from Windows, the command may fail when using absolute Windows paths. Use relative paths or the commands specified below.

  1. Copy the certificate from your file system to the container.
type <local-certificate-path> | kubectl exec -i -n <namespace> -c arc-sqlmi <pod-name> -- tee <pod-certificate-path>

Example:

type $HOME\sqlcerts\servercert.crt | kubectl exec -i -n arc-ns -c arc-sqlmi sql-0 -- tee /var/opt/mssql/data/servercert.crt
  1. Copy the private key from your file system to the container.
type <local-private-key-path> | kubectl exec -i -n <namespace> -c arc-sqlmi <pod-name> -- tee <pod-private-key-path>

Example:

type $HOME\sqlcerts\servercert.key | kubectl exec -i -n arc-ns -c arc-sqlmi sql-0 -- tee /var/opt/mssql/data/servercert.key
  1. Create the certificate using file paths from /var/opt/mssql/data.

    USE master;
    GO
    
    CREATE CERTIFICATE <certicate-name>
    FROM FILE = '<certificate-path>'
    WITH PRIVATE KEY ( FILE = '<private-key-path>',
        DECRYPTION BY PASSWORD = '<UseStrongPasswordHere>' );
    

    Example:

    USE master;
    GO
    
    CREATE CERTIFICATE MyServerCertRestored
    FROM FILE = '/var/opt/mssql/data/servercert.crt'
    WITH PRIVATE KEY ( FILE = '/var/opt/mssql/data/servercert.key',
        DECRYPTION BY PASSWORD = '<UseStrongPasswordHere>' );
    
  2. Delete the certificate and private key from the container.

    kubectl exec -it --namespace <namespace> --container arc-sqlmi <pod-name> -- bash -c "rm <certificate-path> <private-key-path>
    

    Example:

    kubectl exec -it --namespace arc-ns --container arc-sqlmi sql-0 -- bash -c "rm /var/opt/mssql/data/servercert.crt /var/opt/mssql/data/servercert.key"
    

Next steps

Transparent data encryption