Encrypt data with customer-managed encryption keys

This document shows how to use customer-managed encryption keys (CMEK) to encrypt and control data-at-rest in a cloud service through Cloud Key Management Service . CMEK is integrated with code customization for Gemini Code Assist. Gemini Code Assist doesn't support the use of Cloud EKM keys.

In this document, you do the following:

• Learn how to create a CMEK.
• Grant permissions to the Gemini Code Assist service account.
• Create a code repository index with a CMEK.
• Remove access to a CMEK repository.

By default, Gemini for Google Cloud encrypts customer content at rest . Gemini handles encryption for you without any additional actions on your part. This option is called Google default encryption .

After you set up your resources with CMEKs, the experience of accessing your Gemini resources is similar to using Google default encryption. For more information about your encryption options, see Customer-managed encryption keys (CMEK) .

Before you begin

1. In one of the following development environments, set up the gcloud CLI:

   • Cloud Shell: to use an online terminal with the gcloud CLI already set up, launch the Cloud Shell editor .

   • Local shell: to use a local development environment, install and initialize the gcloud CLI.

   If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity .

2. In the development environment where you set up the gcloud CLI, run the gcloud components update command to make sure that you have updated all installed components of the gcloud to the latest version.

    gcloud  
   components  
   update 
   

Create a CMEK and grant permissions

To create a CMEK and grant the Gemini Code Assist service account permissions on the key, perform the following tasks:

1. In the Google Cloud project where you want to manage your keys, do the following:

   1. Enable the Cloud Key Management Service API .

   2. Create the key ring and key directly in Cloud KMS.

2. Grant the CryptoKey Encrypter/Decrypter IAM role ( roles/cloudkms.cryptoKeyEncrypterDecrypter ) to the Gemini Code Assist service account. Grant this permission on the key that you created.

   Console

   1. Go to Key management.

      Go to Key management

   2. Select the key that you created.

   3. Grant access to the Gemini Code Assist service account:

      1. Click Add principal.
      2. Add the Gemini Code Assist service account. The service account is service- PROJECT_NUMBER @gcp-sa-cloudaicompanions. , where PROJECT_NUMBER is the project number of the Google Cloud project where Gemini Code Assist is enabled.
      3. In Select a role, select Cloud KMS> Cloud KMS CryptoKey Encrypter/Decrypter.
      4. Click Save.

   4. Repeat the previous step to grant access to the account that will create the code repository index with a CMEK.

   5. Return to the Key management page and select the key again.

   6. Select Show info panel. You should see roles in the Role/Membercolumn.

   gcloud

   1. To grant access to the Gemini Code Assist service account, in a shell environment, use the kms keys add-iam-policy-binding command :

       gcloud kms keys add-iam-policy-binding KEY_NAME 
      \
          --project= PROJECT_ID 
      \
          --location= LOCATION 
      \
          --keyring= KEYRING_NAME 
      \
          --member="serviceAccount:service- PROJECT_NUMBER 
      @gcp-sa-cloudaicompanion." \
          --role="roles/cloudkms.cryptoKeyEncrypterDecrypter" 
      

      Replace the following:

      • KEY_NAME : the key name.
      • PROJECT_ID : the ID of the project that contains the key.
      • LOCATION : the key location.
      • KEYRING_NAME : the key ring name.
      • PROJECT_NUMBER : the project number of the Google Cloud project with Gemini Code Assist enabled.

   2. Repeat the previous step to grant access to the account that will create the code repository index with a CMEK.

   For more information about this command, see the gcloud kms keys add-iam-policy-binding documentation .

You can now create a code repository index with a CMEK using the API, and specify the key to use for encryption.

Create a code repository index with a CMEK

To create a new repository that has CMEK protection, do one of the following:

 gcloud gemini code-repository-indexes create CODE_REPOSITORY_INDEX_NAME 
\
    --location= LOCATION 
\
    --kms-key="projects/ KEY_PROJECT_ID 
/locations/ LOCATION 
/keyRings/ KEYRING_NAME 
/cryptoKeys/ KEY_NAME 
" 

Remove access to a CMEK repository

There are several ways to remove access to a CMEK-encrypted repository:

• Revoke the Cloud KMS CryptoKey Encrypter/Decrypter role from the Gemini Code Assist service account using the API Console or the gcloud .
• Temporarily disable the CMEK.
• Permanently destroy the CMEK.

We recommend that you revoke the permissions from the Gemini Code Assist service account before disabling or destroying a key. Changes to permissions are consistent within seconds, so you can observe the impacts of disabling or destroying a key.