Control key version destruction

Google Cloud offers two organization policy constraints to set key version destruction policy across an organization:

• constraints/cloudkms.minimumDestroyScheduledDuration is used to set a minimum length for the scheduled for destruction duration for new keys within the organization.
• constraints/cloudkms.disableBeforeDestroy is used to require that a key version has been disabled before it can be scheduled for destruction.

Before you begin

The instructions on this page assume that you're familiar with using constraints and that you have the required resources and roles.

Required resources

Before you can complete the steps on this page, you must have the following resources:

• An organization.
• Optional: A folder or project resource within your organization.

Required roles

To get the permissions that you need to manage organization policies, ask your administrator to grant you the Organization policy administrator (roles/orgpolicy.policyAdmin) IAM role on the organization. For more information about granting roles, see Manage access to projects, folders, and organizations.

This predefined role contains the permissions required to manage organization policies. To see the exact permissions that are required, expand the Required permissions section:

Required permissions

The following permissions are required to manage organization policies:

• orgpolicy.constraints.list
• orgpolicy.policies.create
• orgpolicy.policies.delete
• orgpolicy.policies.list
• orgpolicy.policies.update
• orgpolicy.policy.get
• orgpolicy.policy.set

You might also be able to get these permissions with custom roles or other predefined roles.

Require a minimum scheduled for destruction duration

The Minimum destroy scheduled duration per key constraint (constraints/cloudkms.minimumDestroyScheduledDuration) is used to set a minimum length for the scheduled for destruction duration for new keys. This constraint overrides the minimum scheduled for destruction duration at the project, folder, or organization level. This constraint reduces the chance of accidentally destroying a key that is still needed. You can set this constraint to a higher value to help make sure you have time to prevent key destruction before it becomes irreversible.

Use higher values for this constraint when unwanted key destruction would be more harmful, such as for production data that is subject to data retention requirements. Use lower values for this constraint when unwanted key destruction would be less harmful, such as for development or testing environments. You can also use lower values to allow timely crypto-shredding. However, as a minimum value, this constraint can't ensure that new keys are created with low scheduled for destruction durations.

To require a minimum scheduled for destruction duration, follow these steps:

1. Get the current policy on the organization resource using the describe command. This command returns the policy directly applied to this resource:

   gcloud org-policies describe \
     constraints/cloudkms.minimumDestroyScheduledDuration \
     --organization=ORGANIZATION_ID
   

   Replace ORGANIZATION_ID with the unique identifier for the organization resource. Organization ID is formatted as decimal numbers, and can't have leading zeros.

   You can also view the organization policy for a folder or a project with the --folder or the --project flags, and the folder ID or project ID, respectively.

   The response returns the current organization policy, if one exists. The output is similar to the following:

   name: organizations/ORGANIZATION_ID/policies/cloudkms.minimumDestroyScheduledDuration
   spec:
     etag: COTP+KYGELiCmsoB
     inheritFromParent: true
     rules:
     - values:
         allowedValues:
         - in:7d
     updateTime: '2023-08-17T14:00:04.424051Z'
   

   If a policy isn't set, the describe command returns a NOT_FOUND error:

   ERROR: (gcloud.org-policies.describe) NOT_FOUND: Requested entity was not found.
   

2. Set the policy on the organization using the set-policy command. This command overwrites any policy currently attached to the resource.

   1. Create a temporary file /tmp/policy.yaml to store the policy:

      name: organizations/ORGANIZATION_ID/policies/cloudkms.minimumDestroyScheduledDuration
      spec:
        rules:
        - values:
            allowedValues:
            - in:MINIMUM_DURATION
      

      Replace the following:

      • ORGANIZATION_ID: the numerical ID of your organization.
      • MINIMUM_DURATION: the minimum duration for the scheduled for destruction state for keys in this organization, in days. Must be one of the following values: 7d, 15d, 30d, 60d, 90d, or 120d.

   2. Run the set-policy command:

      gcloud org-policies set-policy /tmp/policy.yaml
      

3. View the current effective policy using describe --effective. This command returns the organization policy as it is evaluated at this point in the resource hierarchy with inheritance included.

   gcloud org-policies describe \
     constraints/cloudkms.minimumDestroyScheduledDuration --effective \
     --organization=ORGANIZATION_ID
   

   The output is similar to the following:

   name: organizations/ORGANIZATION_ID/policies/cloudkms.minimumDestroyScheduledDuration
   spec:
     rules:
       - values:
           allowedValues:
           - 30d
           - 15d
           - 90d
           - 60d
           - 7d
           - 120d
   

   Because this organization policy was set at the organization level, it is inherited by all child resources that allow inheritance.

Require keys to be disabled before destruction

The Restrict key destruction to disabled keys constraint (constraints/cloudkms.disableBeforeDestroy) lets you require that a key has been disabled before you can schedule the key for destruction. Disabling a key prior to destroying it is a recommended best practice because it helps you to validate that the key is not in use. You can combine this constraint with careful Identity and Access Management policy to create a multi-step destruction process that requires cooperation from multiple roles.

To use this constraint to create a multi-step destruction process, make sure that no user has both the cloudkms.cryptoKeyVersions.update and the cloudkms.cryptoKeyVersions.destroy permissions. This use case requires that you use custom roles.

To require that a key is in the disabled state before you can schedule the key for destruction, follow these steps:

What's next

• Learn more about key version states.
• Destroy and restore a key version.