Convert CSEK to CMEK

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Sample converts CSEK to CMEK.

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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.


using Google.Cloud.Storage.V1;
using System;
using System.IO;

public class ObjectCsekToCmekSample
{
    public void ObjectCsekToCmek(
        string projectId = "your-project-id",
        string bucketName = "your-unique-bucket-name",
        string objectName = "your-object-name",
        string currrentEncryptionKey = "TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=",
        string keyLocation = "us-west1",
        string kmsKeyRing = "kms-key-ring",
        string kmsKeyName = "key-name")
    {
        string keyPrefix = $"projects/{projectId}/locations/{keyLocation}";
        string fullKeyringName = $"{keyPrefix}/keyRings/{kmsKeyRing}";
        string fullKeyName = $"{fullKeyringName}/cryptoKeys/{kmsKeyName}";
        var storage = StorageClient.Create();

        using var outputStream = new MemoryStream();
        storage.DownloadObject(bucketName, objectName, outputStream, new DownloadObjectOptions()
        {
            EncryptionKey = EncryptionKey.Create(Convert.FromBase64String(currrentEncryptionKey))
        });

        outputStream.Position = 0;

        storage.UploadObject(bucketName, objectName, null, outputStream, new UploadObjectOptions()
        {
            KmsKeyName = fullKeyName
        });

        Console.WriteLine($"Object {objectName} in bucket {bucketName} is now managed" +
            $" by the KMS key ${kmsKeyName}  instead of a customer-supplied encryption key");
    }
}

C++

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

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name, std::string const& old_csek_key_base64,
   std::string const& new_cmek_key_name) {
  StatusOr<gcs::ObjectMetadata> metadata = client.RewriteObjectBlocking(
      bucket_name, object_name, bucket_name, object_name,
      gcs::SourceEncryptionKey::FromBase64Key(old_csek_key_base64),
      gcs::DestinationKmsKeyName(new_cmek_key_name));
  if (!metadata) throw std::runtime_error(metadata.status().message());

  std::cout << "Changed object " << metadata->name() << " in bucket "
            << metadata->bucket()
            << " from using CSEK to CMEK key.\nFull Metadata: " << *metadata
            << "\n";
}

Go

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

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

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

// сhangeObjectCSEKtoKMS changes the key used to encrypt an object from
// a customer-supplied encryption key to a customer-managed encryption key.
func сhangeObjectCSEKToKMS(w io.Writer, bucket, object string, encryptionKey []byte, kmsKeyName string) error {
	// bucket := "bucket-name"
	// object := "object-name"

	// encryptionKey is the Base64 encoded decryption key, which should be the same
	// key originally used to encrypt the object.
	// encryptionKey := []byte("TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=")

	// kmsKeyName is the name of the KMS key to manage this object with.
	// kmsKeyName := "projects/projectId/locations/global/keyRings/keyRingID/cryptoKeys/cryptoKeyID"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %v", err)
	}
	defer client.Close()

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

	o := client.Bucket(bucket).Object(object)

	// Optional: set a generation-match precondition to avoid potential race
	// conditions and data corruptions. The request to upload is aborted if the
	// object's generation number does not match your precondition.
	attrs, err := o.Attrs(ctx)
	if err != nil {
		return fmt.Errorf("object.Attrs: %v", err)
	}
	o = o.If(storage.Conditions{GenerationMatch: attrs.Generation})

	// You can't change an object's encryption key directly. Instead, you must
	// rewrite the object using the new key.
	src := o.Key(encryptionKey)
	c := o.CopierFrom(src)
	c.DestinationKMSKeyName = kmsKeyName
	if _, err := c.Run(ctx); err != nil {
		return fmt.Errorf("Copier.Run: %v", err)
	}
	fmt.Fprintf(w, "Object %v in bucket %v is now managed by the KMS key %v instead of a customer-supplied encryption key\n", object, bucket, kmsKeyName)
	return nil
}

Java

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

import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

public class ChangeObjectCsekToKms {
  public static void changeObjectFromCsekToKms(
      String projectId,
      String bucketName,
      String objectName,
      String decryptionKey,
      String kmsKeyName) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

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

    // The ID of your GCS object
    // String objectName = "your-object-name";

    // The Base64 encoded decryption key, which should be the same key originally used to encrypt
    // the object
    // String decryptionKey = "TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=";

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

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    BlobId blobId = BlobId.of(bucketName, objectName);
    Blob blob = storage.get(blobId);
    if (blob == null) {
      System.out.println("The object " + objectName + " wasn't found in " + bucketName);
      return;
    }

    // Optional: set a generation-match precondition to avoid potential race
    // conditions and data corruptions. The request to upload returns a 412 error if
    // the object's generation number does not match your precondition.
    Storage.BlobSourceOption precondition =
        Storage.BlobSourceOption.generationMatch(blob.getGeneration());

    Storage.CopyRequest request =
        Storage.CopyRequest.newBuilder()
            .setSource(blobId)
            .setSourceOptions(Storage.BlobSourceOption.decryptionKey(decryptionKey), precondition)
            .setTarget(blobId, Storage.BlobTargetOption.kmsKeyName(kmsKeyName))
            .build();
    storage.copy(request);

    System.out.println(
        "Object "
            + objectName
            + " in bucket "
            + bucketName
            + " is now managed by the KMS key "
            + kmsKeyName
            + " instead of a customer-supplied encryption key");
  }
}

Node.js

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

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

// The ID of your GCS file
// const fileName = 'your-file-name';

// The Base64 encoded decryption key, which should be the same key originally
// used to encrypt the file
// const encryptionKey = 'TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=';

// The name of the KMS key to manage this file with
// const kmsKeyName = 'projects/your-project-id/locations/global/keyRings/your-key-ring/cryptoKeys/your-key';

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

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

async function changeFileCSEKToCMEK() {
  const rotateEncryptionKeyOptions = {
    kmsKeyName,
    // Optional: set a generation-match precondition to avoid potential race
    // conditions and data corruptions. The request to upload is aborted if the
    // object's generation number does not match your precondition.
    preconditionOpts: {
      ifGenerationMatch: generationMatchPrecondition,
    },
  };

  console.log(rotateEncryptionKeyOptions);

  await storage
    .bucket(bucketName)
    .file(fileName, {
      encryptionKey: Buffer.from(encryptionKey, 'base64'),
    })
    .rotateEncryptionKey({
      rotateEncryptionKeyOptions,
    });

  console.log(
    `file ${fileName} in bucket ${bucketName} is now managed by KMS key ${kmsKeyName} instead of customer-supplied encryption key`
  );
}

changeFileCSEKToCMEK().catch(console.error);

PHP

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

use Google\Cloud\Storage\StorageClient;

/**
 * Migrate an object from a Customer-Specified Encryption Key to a Customer-Managed
 * Encryption Key.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 * @param string $objectName The name of your Cloud Storage object.
 * @param string $decryptionKey The Base64 encoded decryption key, which should
 *     be the same key originally used to encrypt the object.
 * @param string $kmsKeyName The name of the KMS key to manage this object.
 *     Key names are provided in the following format:
 *     `projects/<PROJECT>/locations/<LOCATION>/keyRings/<RING_NAME>/cryptoKeys/<KEY_NAME>`.
 */
function object_csek_to_cmek($bucketName, $objectName, $decryptionKey, $kmsKeyName)
{
    // $bucketName = 'my-bucket';
    // $objectName = 'my-object';
    // $decryptionKey = 'TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=';
    // $kmsKeyName = "";

    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);

    $object = $bucket->object($objectName, [
        'encryptionKey' => $decryptionKey,
    ]);

    $object->rewrite($bucketName, [
        'destinationKmsKeyName' => $kmsKeyName,
    ]);

    printf(
        'Object %s in bucket %s is now managed by the KMS key %s instead of a customer-supplied encryption key',
        $objectName,
        $bucketName,
        $kmsKeyName
    );
}

Python

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

from google.cloud import storage


def object_csek_to_cmek(bucket_name, blob_name, encryption_key, kms_key_name):
    """Change a blob's customer-supplied encryption key to KMS key"""
    # bucket_name = "your-bucket-name"
    # blob_name = "your-object-name"
    # encryption_key = "TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g="
    # kms_key_name = "projects/PROJ/locations/LOC/keyRings/RING/cryptoKey/KEY"

    storage_client = storage.Client()
    bucket = storage_client.bucket(bucket_name)

    current_encryption_key = base64.b64decode(encryption_key)
    source_blob = bucket.blob(blob_name, encryption_key=current_encryption_key)

    destination_blob = bucket.blob(blob_name, kms_key_name=kms_key_name)
    token, rewritten, total = destination_blob.rewrite(source_blob)

    while token is not None:
        token, rewritten, total = destination_blob.rewrite(source_blob, token=token)

    print(
        "Blob {} in bucket {} is now managed by the KMS key {} instead of a customer-supplied encryption key".format(
            blob_name, bucket_name, kms_key_name
        )
    )
    return destination_blob

Ruby

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

def object_csek_to_cmek bucket_name:, file_name:, encryption_key:, kms_key_name:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  # The ID of your GCS object
  # file_name = "your-file-name"

  # The Base64 encoded encryption key, which should be the same key originally used to encrypt the object
  # encryption_key = "TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g="

  # The name of the KMS key to manage this object with
  # kms_key_name = "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, skip_lookup: true

  file = bucket.file file_name, encryption_key: encryption_key

  file.rotate encryption_key: encryption_key, new_kms_key: kms_key_name

  puts "File #{file_name} in bucket #{bucket_name} is now managed by the KMS key #{kms_key_name} instead of a " \
       "customer-supplied encryption key"
end

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