Set a default KMS key for a bucket

Sets a default CMEK for a bucket.

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For detailed documentation that includes this code sample, see the following:

Code sample

C++

For more information, see the Cloud Storage C++ API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& key_name) {
  StatusOr<gcs::BucketMetadata> updated = client.PatchBucket(
      bucket_name, gcs::BucketMetadataPatchBuilder().SetEncryption(
                       gcs::BucketEncryption{key_name}));
  if (!updated) throw std::move(updated).status();

  if (!updated->has_encryption()) {
    std::cerr << "The change to set the encryption attribute on bucket "
              << updated->name()
              << " was successful, but the encryption is not set."
              << "This is unexpected, maybe a concurrent change?\n";
    return;
  }

  std::cout << "Successfully set default KMS key on bucket "
            << updated->name() << " to "
            << updated->encryption().default_kms_key_name << "."
            << "\nFull metadata: " << *updated << "\n";
}

C#

For more information, see the Cloud Storage C# API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.


using Google.Apis.Storage.v1.Data;
using Google.Cloud.Storage.V1;
using System;

public class EnableDefaultKMSKeySample
{
    public Bucket EnableDefaultKMSKey(
        string projectId = "your-project-id",
        string bucketName = "your-unique-bucket-name",
        string keyLocation = "us-west1",
        string kmsKeyRing = "kms-key-ring",
        string kmsKeyName = "key-name")
    {
        // KMS Key identifier of an already created KMS key.
        // If you use the Google.Cloud.Kms.V1 library, you can construct these names using helper class CryptoKeyName.
        // var fullKeyName = new CryptoKeyName(projectId, keyLocation, kmsKeyRing, kmsKeyName).ToString();
        string keyPrefix = $"projects/{projectId}/locations/{keyLocation}";
        string fullKeyringName = $"{keyPrefix}/keyRings/{kmsKeyRing}";
        string fullKeyName = $"{fullKeyringName}/cryptoKeys/{kmsKeyName}";
        var storage = StorageClient.Create();
        var bucket = storage.GetBucket(bucketName, new GetBucketOptions { Projection = Projection.Full });
        bucket.Encryption = new Bucket.EncryptionData { DefaultKmsKeyName = fullKeyName };
        var updatedBucket = storage.UpdateBucket(bucket);
        Console.WriteLine($"Default KMS key for {bucketName} was set to {kmsKeyName}.");
        return updatedBucket;
    }
}

Go

For more information, see the Cloud Storage Go API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

import (
	"context"
	"fmt"
	"io"
	"time"

	"cloud.google.com/go/storage"
)

// setBucketDefaultKMSKey sets the Cloud KMS encryption key for the bucket.
func setBucketDefaultKMSKey(w io.Writer, bucketName, keyName string) error {
	// bucketName := "bucket-name"
	// keyName := "key"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
	defer cancel()

	bucket := client.Bucket(bucketName)
	bucketAttrsToUpdate := storage.BucketAttrsToUpdate{
		Encryption: &storage.BucketEncryption{DefaultKMSKeyName: keyName},
	}
	if _, err := bucket.Update(ctx, bucketAttrsToUpdate); err != nil {
		return fmt.Errorf("Bucket(%q).Update: %w", bucketName, err)
	}
	fmt.Fprintf(w, "Default KMS Key Name: %v", bucketAttrsToUpdate.Encryption.DefaultKMSKeyName)
	return nil
}

Java

For more information, see the Cloud Storage Java API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.


import com.google.cloud.storage.Bucket;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.Storage.BucketTargetOption;
import com.google.cloud.storage.StorageException;
import com.google.cloud.storage.StorageOptions;

public class SetBucketDefaultKmsKey {
  public static void setBucketDefaultKmsKey(String projectId, String bucketName, String kmsKeyName)
      throws StorageException {
    // The ID of your GCP project
    // String projectId = "your-project-id";

    // The ID of your GCS bucket
    // String bucketName = "your-unique-bucket-name";

    // The name of the KMS key to use as a default
    // String kmsKeyName =
    // "projects/your-project-id/locations/us/keyRings/my_key_ring/cryptoKeys/my_key"

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    // first look up the bucket, so we will have its metageneration
    Bucket bucket = storage.get(bucketName);

    Bucket updated =
        storage.update(
            bucket.toBuilder().setDefaultKmsKeyName(kmsKeyName).build(),
            BucketTargetOption.metagenerationMatch());

    System.out.println(
        "KMS Key "
            + updated.getDefaultKmsKeyName()
            + "was set to default for bucket "
            + bucketName);
  }
}

Node.js

For more information, see the Cloud Storage Node.js API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// The ID of your GCS bucket
// const bucketName = 'your-unique-bucket-name';

// The name of the KMS-key to use as a default
// const defaultKmsKeyName = 'my-key';

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Creates a client
const storage = new Storage();

async function enableDefaultKMSKey() {
  await storage.bucket(bucketName).setMetadata({
    encryption: {
      defaultKmsKeyName,
    },
  });

  console.log(
    `Default KMS key for ${bucketName} was set to ${defaultKmsKeyName}.`
  );
}

enableDefaultKMSKey().catch(console.error);

PHP

For more information, see the Cloud Storage PHP API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

use Google\Cloud\Storage\StorageClient;

/**
 * Enable a bucket's requesterpays metadata.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $kmsKeyName The KMS key to use as the default KMS key.
 *     Key names are provided in the following format:
 *     `projects/<PROJECT>/locations/<LOCATION>/keyRings/<RING_NAME>/cryptoKeys/<KEY_NAME>`.
 */
function enable_default_kms_key(string $bucketName, string $kmsKeyName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $bucket->update([
        'encryption' => [
            'defaultKmsKeyName' => $kmsKeyName
        ]
    ]);
    printf('Default KMS key for %s was set to %s' . PHP_EOL,
        $bucketName,
        $bucket->info()['encryption']['defaultKmsKeyName']);
}

Python

For more information, see the Cloud Storage Python API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

from google.cloud import storage


def enable_default_kms_key(bucket_name, kms_key_name):
    """Sets a bucket's default KMS key."""
    # bucket_name = "your-bucket-name"
    # kms_key_name = "projects/PROJ/locations/LOC/keyRings/RING/cryptoKey/KEY"

    storage_client = storage.Client()
    bucket = storage_client.get_bucket(bucket_name)
    bucket.default_kms_key_name = kms_key_name
    bucket.patch()

    print(
        "Set default KMS key for bucket {} to {}.".format(
            bucket.name, bucket.default_kms_key_name
        )
    )

Ruby

For more information, see the Cloud Storage Ruby API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

def set_bucket_default_kms_key bucket_name:, default_kms_key:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  # The name of the KMS key to manage this object with
  # default_kms_key = "projects/your-project-id/locations/global/keyRings/your-key-ring/cryptoKeys/your-key"

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new
  bucket  = storage.bucket bucket_name

  bucket.default_kms_key = default_kms_key

  puts "Default KMS key for #{bucket.name} was set to #{bucket.default_kms_key}"
end

What's next

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