Use customer-managed encryption keys (CMEK)

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

If you want to control your encryption keys, then you can use customer-managed encryption keys (CMEKs) in Cloud KMS with CMEK-integrated services including Eventarc. Using Cloud KMS keys gives you control over their protection level, location, rotation schedule, usage and access permissions, and cryptographic boundaries. Using Cloud KMS also lets you view audit logs and control key life cycles. Instead of Google owning and managing the symmetric key encryption keys (KEKs) that protect your data, you control and manage these keys in Cloud KMS.

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

Customer-managed encryption keys are stored as software keys, in a Cloud HSM cluster, or externally using Cloud External Key Manager.

What is protected with CMEK

You can configure CMEK to encrypt the event messages that pass through the following resources:

  • MessageBus—An Eventarc Advanced bus
  • Pipeline—An Eventarc Advanced pipeline
  • GoogleApiSource—A resource which represents a subscription to Google API events for a particular bus

For more information, see the Eventarc Advanced overview.

When you enable CMEK for a resource, it protects the data associated with the resource in that region by using an encryption key that only you can access.

Cloud KMS and Eventarc are regionalized services. The region for the Cloud KMS key and the protected Eventarc Advanced resource must be the same.

Before you begin

Before using this feature in Eventarc, you must perform the following actions:

Console

  1. Enable the Cloud KMS and Eventarc APIs.

    Enable the APIs

  2. Create a key ring.
  3. Create a key for a specified key ring.

gcloud

  1. Update gcloud components. 
    gcloud components update
  2. Enable the Cloud KMS and Eventarc APIs for the project that will store your encryption keys. 
    gcloud services enable cloudkms.googleapis.com eventarc.googleapis.com
  3. Create a key ring.
  4. Create a key for a specified key ring.

For information on all flags and possible values, run the command with the --help flag.

Grant the Eventarc service account access to a key

To grant the Eventarc service account access to the Cloud KMS key, add the service account as a principal of the key, and grant the service account the Cloud KMS CryptoKey Encrypter/Decrypter role:

Console

When you enable CMEK for a bus or pipeline using the Google Cloud console, you are prompted to grant the Cloud KMS CryptoKey Encrypter/Decrypter role to the service account. For more information, in this document, see Enable CMEK for a bus or Enable CMEK for a pipeline.

gcloud 

 gcloud kms keys add-iam-policy-binding KEY_NAME \
     --keyring KEY_RING \
     --location REGION \
     --member serviceAccount:SERVICE_AGENT_EMAIL \
     --role roles/cloudkms.cryptoKeyEncrypterDecrypter

Replace the following:

  • KEY_NAME: the name of the key—for example, my-key
  • KEY_RING: the name of the key ring—for example, my-keyring
  • REGION: the location of the key—for example, us-central1

  • SERVICE_AGENT_EMAIL: the email address of the service account with the eventarc.serviceAgentrole

    For example, service-PROJECT_NUMBER@gcp-sa-eventarc.iam.gserviceaccount.com. For more information, see Service agents.

Enable CMEK for a bus

When you enable CMEK for an Eventarc Advanced bus, all messages that pass through the bus are fully encrypted with that CMEK key.

Console

  1. In the Google Cloud console, go to the Eventarc > Bus page.

    Go to Bus

  2. You can create a bus or, if you are updating a bus, click the name of the bus.

  3. In the Bus details page, click Edit.

  4. In the Edit bus page, for Encryption, select Cloud KMS key.

  5. In the Key type list, select a method to manage your keys.

    You can manage your keys manually or you can use Autokey which lets you generate key rings and keys on-demand. If the Autokey option is disabled, it isn't yet integrated with the current resource type.

  6. Select a customer-managed key.

  7. Optional: To manually enter the resource name of the key, in the Select a customer-managed key list, click Enter key manually, and enter the key name in the specified format.

  8. If prompted, grant the cloudkms.cryptoKeyEncrypterDecrypter role to the Eventarc Service Agent.

  9. Click Save.

gcloud

Use the gcloud beta eventarc message-buses update command to enable CMEK for your bus:

gcloud beta eventarc message-buses update BUS_NAME \
    --location=REGION \
    --crypto-key=KEY

Replace the following:

  • BUS_NAME: the ID or fully qualified identifier of your bus
  • REGION: a supported Eventarc Advanced location

  • KEY: the fully qualified Cloud KMS key name in the format projects/PROJECT_NAME/locations/REGION/keyRings/RING_NAME/cryptoKeys/KEY_NAME

    The REGION of the key must match the location of the bus to be protected.

Verify Cloud KMS usage

Verify that the bus is now CMEK-compliant.

Console

  1. In the Google Cloud console, go to the Eventarc > Bus page.

    Go to Bus

  2. Click the name of the bus that you have protected using CMEK.

  3. On the Bus details page, the Encryption status displays the message, Event messages encrypted using customer-managed encryption keys.

gcloud

Use the gcloud beta eventarc message-buses describe command to describe your bus:

 gcloud beta eventarc message-buses describe BUS_NAME \
     --location=REGION

The output should be similar to the following:

 cryptoKeyName: projects/PROJECT_ID/locations/REGION/keyRings/RING_NAME/cryptoKeys/KEY_NAME
 name: projects/PROJECT_ID/locations/REGION/messageBuses/BUS_NAME
 updateTime: '2022-06-28T17:24:56.365866104Z'

The cryptokeyName value shows the Cloud KMS key used for the bus.

Disable CMEK for a bus

You can disable the CMEK protection associated with a bus. The events that are delivered through the bus are still protected by Google-owned and Google-managed encryption keys.

Console

  1. In the Google Cloud console, go to the Eventarc > Bus page.

    Go to Bus

  2. Click the name of the bus.

  3. In the Bus details page, click Edit.

  4. On the Edit bus page, clear the Use a customer-managed encryption key (CMEK) checkbox.

  5. Click Save.

gcloud

Use the gcloud beta eventarc message-buses update command to disable CMEK for your bus:

gcloud beta eventarc message-buses update BUS_NAME \
    --location=REGION \
    --clear-crypto-key

Enable CMEK for a pipeline

When you enable CMEK for an Eventarc Advanced pipeline, all messages that pass through the pipeline are fully encrypted with that CMEK key.

Console

  1. In the Google Cloud console, go to the Eventarc > Pipelines page.

    Go to Pipelines

  2. You can create a pipeline or, if you are updating a pipeline, click the name of the pipeline.

  3. In the Pipeline details page, click Edit.

  4. In the Edit pipeline page, for Encryption, select Cloud KMS key.

  5. In the Key type list, select a method to manage your keys.

    You can manage your keys manually or you can use Autokey which lets you generate key rings and keys on-demand. If the Autokey option is disabled, it isn't yet integrated with the current resource type.

  6. Select a customer-managed key.

  7. Optional: To manually enter the resource name of the key, in the Select a customer-managed key list, click Enter key manually, and enter the key name in the specified format.

  8. If prompted, grant the cloudkms.cryptoKeyEncrypterDecrypter role to the Eventarc Service Agent.

  9. Click Save.

gcloud

Use the gcloud beta eventarc pipelines update command to enable CMEK for a pipeline:

 gcloud beta eventarc pipelines update PIPELINE_NAME \
     --location=REGION \
     --crypto-key=KEY

Replace the following:

  • PIPELINE_NAME: the ID or fully qualified identifier of your pipeline
  • REGION: a supported Eventarc Advanced location

  • KEY: the fully qualified Cloud KMS key name in the format projects/PROJECT_NAME/locations/REGION/keyRings/RING_NAME/cryptoKeys/KEY_NAME

    The REGION of the key must match the location of the pipeline to be protected.

Verify Cloud KMS usage

Verify that the pipeline is now CMEK-compliant.

Console

  1. In the Google Cloud console, go to the Eventarc > Pipelines page.

    Go to Pipelines

  2. Click the name of the pipeline that you have protected using CMEK.

  3. On the Pipeline details page, the Encryption status displays the message, Event messages encrypted using customer-managed encryption keys.

gcloud

Use the gcloud beta eventarc pipelines describe command to verify CMEK for your pipeline:

 gcloud beta eventarc pipelines describe PIPELINE_NAME \
     --location=REGION

The output should be similar to the following:

 createTime: '2022-06-28T18:05:52.403999904Z'
 cryptoKeyName: projects/PROJECT_ID/locations/REGION/keyRings/RING_NAME/cryptoKeys/KEY_NAME
 destinations: ...
 name: projects/PROJECT_ID/locations/REGION/pipelines/PIPELINE_NAME
 uid: 5ea277f9-b4b7-4e7f-a8e0-6ca9d7204fa3
 updateTime: '2022-06-28T18:09:18.650727516Z'

The cryptokeyName value shows the Cloud KMS key used for the pipeline.

Disable CMEK for a pipeline

You can disable the CMEK protection associated with a pipeline. The events that are delivered through the pipeline are still protected by Google-owned and Google-managed encryption keys.

Console

  1. In the Google Cloud console, go to the Eventarc > Pipelines page.

    Go to Pipelines

  2. Click the name of the pipeline.

  3. In the Pipeline details page, click Edit.

  4. On the Edit pipeline page, clear the Use a customer-managed encryption key (CMEK) checkbox.

  5. Click Save.

gcloud

Use the gcloud beta eventarc pipelines update command to disable CMEK for your pipeline:

gcloud beta eventarc pipelines update PIPELINE_NAME \
    --location=REGION \
    --clear-crypto-key

Enable CMEK for Google API sources

When you enable CMEK for a GoogleApiSource resource, all messages that are collected for that resource are fully encrypted with the CMEK key.

Console

  1. In the Google Cloud console, go to the Eventarc > Bus page.

    Go to Bus

  2. You can create a bus or, if you are updating a bus, click the name of the bus.

  3. In the Bus details page, click Edit.

  4. To add a message source, click Add source.

    If a message source already exists, you must first delete it and then add a new message source.

  5. In the Add message source pane, for the Google API message provider, accept the default of google-api-source.

  6. For Encryption, select Cloud KMS key and do the following:

    1. In the Key type list, select a method to manage your keys.

      You can manage your keys manually or you can use Autokey which lets you generate key rings and keys on-demand. If the Autokey option is disabled, it isn't yet integrated with the current resource type.

    2. In the Select a customer-managed key, select a key.

      You must select a region before you can view your customer-managed keys.

    3. Optional: To manually enter the resource name of the key, in the Select a customer-managed key list, click Enter key manually, and enter the key name in the specified format.

    4. If prompted, grant the cloudkms.cryptoKeyEncrypterDecrypter role to the Eventarc Service Agent.

  7. Click Create.

    This enables the automatic collection of events coming directly from Google sources, and all event messages are fully encrypted with the CMEK key.

    Only events from resources in the same Google Cloud project as the GoogleApiSource are published. For more information, see Publish events from Google sources.

  8. Click Save.

gcloud

Use the gcloud beta eventarc google-api-sources update command to enable CMEK for your GoogleApiSource resource:

gcloud beta eventarc google-api-sources update GOOGLE_API_SOURCE_NAME \
    --location=REGION \
    --crypto-key=KEY

Replace the following:

  • GOOGLE_API_SOURCE_NAME: the ID or fully qualified identifier of your GoogleApiSource resource
  • REGION: a supported Eventarc Advanced location

  • KEY: the fully qualified Cloud KMS key name in the format projects/PROJECT_NAME/locations/REGION/keyRings/RING_NAME/cryptoKeys/KEY_NAME

    The REGION of the key must match the location of the resource to be protected.

Verify Cloud KMS usage

Verify that the resource is now CMEK-compliant.

Console

  1. In the Google Cloud console, go to the Eventarc > Bus page.

    Go to Bus

  2. Click the name of the bus whose message source you have protected using a Cloud KMS key.

  3. In the Bus details page, click Edit.

    The key that is encrypting your message source should be listed.

gcloud

Use the gcloud beta eventarc google-api-sources describe command to verify CMEK for your GoogleApiSource resource:

  gcloud beta eventarc google-api-sources describe GOOGLE_API_SOURCE_NAME \
      --location=REGION

The output should be similar to the following:

  createTime: '2022-06-28T18:05:52.403999904Z'
  cryptoKeyName: projects/PROJECT_ID/locations/REGION/keyRings/RING_NAME/cryptoKeys/KEY_NAME
  destination: projects/PROJECT_ID/locations/REGION/messageBuses/BUS_NAME
  name: projects/PROJECT_ID/locations/REGION/googleApiSources/GOOGLE_API_SOURCE_NAME
  uid: 5ea277f9-b4b7-4e7f-a8e0-6ca9d7204fa3
  updateTime: '2022-06-28T18:09:18.650727516Z'

The cryptokeyName value shows the Cloud KMS key used for the pipeline.

Disable CMEK for Google API sources

You can disable the CMEK protection associated with Google API sources. The events that are collected through the GoogleApiSource resource are still protected by Google-owned and Google-managed encryption keys.

Console

  1. In the Google Cloud console, go to the Eventarc > Bus page.

    Go to Bus

  2. Click the name of the bus whose message source you have protected using CMEK.

  3. In the Bus details page, click Edit.

  4. To delete the message source that is encrypted by a Cloud KMS key, click Delete resource.

  5. If necessary, re-add the message source.

gcloud

Use the gcloud beta eventarc google-api-sources update command to disable CMEK for your GoogleApiSource resource:

gcloud beta eventarc google-api-sources update GOOGLE_API_SOURCE_NAME \
    --location=REGION \
    --clear-crypto-key

Disabling and enabling Cloud KMS keys

A key version stores the cryptographic key material that you use to encrypt, decrypt, sign, and verify data. You can disable this key version so that data that was encrypted with the key can't be accessed.

When Eventarc cannot access Cloud KMS keys, event routing fails with FAILED_PRECONDITION errors and event delivery stops. You can enable a key in the Disabled state so that the encrypted data can be accessed again.

Disable Cloud KMS keys

To prevent Eventarc from using the key to encrypt or decrypt your event data, do any of the following:

Although neither operation guarantees instantaneous access revocation, Identity and Access Management (IAM) changes generally propagate faster. For more information, see Cloud KMS resource consistency and Access change propagation.

Re-enable Cloud KMS keys

To resume event delivery and routing, restore access to Cloud KMS.

Audit logging and troubleshooting

Cloud KMS produces audit logs when keys are enabled, disabled, or used by Eventarc Advanced resources to encrypt and decrypt messages. For more information, see the Cloud KMS audit logging information.

To resolve issues that you might encounter when using externally managed keys through Cloud External Key Manager (Cloud EKM), see Cloud EKM error reference.

Pricing

The bus integration does not incur additional costs beyond the key operations, which are billed to your Google Cloud project. The use of CMEK for a pipeline incurs charges for access to the Cloud KMS service based on Pub/Sub pricing.

For more information on the most current pricing information, see Cloud KMS Pricing.

What's next