Upload an object by using CSEK

Upload an object by using customer-supplied encryption keys (CSEK).

Explore further

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& object_name, std::string const& base64_aes256_key) {
  StatusOr<gcs::ObjectMetadata> object_metadata = client.InsertObject(
      bucket_name, object_name, "top secret",
      gcs::EncryptionKey::FromBase64Key(base64_aes256_key));
  if (!object_metadata) throw std::move(object_metadata).status();

  std::cout << "The object " << object_metadata->name()
            << " was created in bucket " << object_metadata->bucket()
            << "\nFull metadata: " << *object_metadata << "\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.Cloud.Storage.V1;
using System;
using System.IO;

public class UploadEncryptedFileSample
{
    public void UploadEncryptedFile(
        string key = "3eFsTXPvqi3BpT2ipFCGirslh1Jgc6ikjoAu2oQ5JcI=",
        string bucketName = "your-unique-bucket-name",
        string localPath = "my-local-path/my-file-name",
        string objectName = "my-file-name")
    {
        var storage = StorageClient.Create();
        using var fileStream = File.OpenRead(localPath);
        storage.UploadObject(bucketName, objectName, null, fileStream, new UploadObjectOptions
        {
            EncryptionKey = EncryptionKey.Create(Convert.FromBase64String(key))
        });
        Console.WriteLine($"Uploaded {objectName}.");
    }
}

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"
)

// uploadEncryptedFile writes an object using AES-256 encryption key.
func uploadEncryptedFile(w io.Writer, bucket, object string, secretKey []byte) error {
	// bucket := "bucket-name"
	// object := "object-name"
	// secretKey := []byte("secret-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*50)
	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.
	// For an object that does not yet exist, set the DoesNotExist precondition.
	o = o.If(storage.Conditions{DoesNotExist: true})
	// If the live object already exists in your bucket, set instead a
	// generation-match precondition using the live object's generation number.
	// attrs, err := o.Attrs(ctx)
	// if err != nil {
	// 	return fmt.Errorf("object.Attrs: %w", err)
	// }
	// o = o.If(storage.Conditions{GenerationMatch: attrs.Generation})

	// Encrypt the object's contents.
	wc := o.Key(secretKey).NewWriter(ctx)
	if _, err := wc.Write([]byte("top secret")); err != nil {
		return fmt.Errorf("Writer.Write: %w", err)
	}
	if err := wc.Close(); err != nil {
		return fmt.Errorf("Writer.Close: %w", err)
	}
	fmt.Fprintf(w, "Uploaded encrypted object %v.\n", object)
	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.BlobId;
import com.google.cloud.storage.BlobInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

public class UploadEncryptedObject {
  public static void uploadEncryptedObject(
      String projectId, String bucketName, String objectName, String filePath, String encryptionKey)
      throws IOException {
    // 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 path to your file to upload
    // String filePath = "path/to/your/file"

    // The key to encrypt the object with
    // String encryptionKey = "TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=";

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    BlobId blobId = BlobId.of(bucketName, objectName);
    BlobInfo blobInfo = BlobInfo.newBuilder(blobId).build();

    // Optional: set a generation-match precondition to avoid potential race
    // conditions and data corruptions. The request returns a 412 error if the
    // preconditions are not met.
    Storage.BlobTargetOption precondition;
    if (storage.get(bucketName, objectName) == null) {
      // For a target object that does not yet exist, set the DoesNotExist precondition.
      // This will cause the request to fail if the object is created before the request runs.
      precondition = Storage.BlobTargetOption.doesNotExist();
    } else {
      // If the destination already exists in your bucket, instead set a generation-match
      // precondition. This will cause the request to fail if the existing object's generation
      // changes before the request runs.
      precondition =
          Storage.BlobTargetOption.generationMatch(
              storage.get(bucketName, objectName).getGeneration());
    }

    storage.create(
        blobInfo,
        Files.readAllBytes(Paths.get(filePath)),
        Storage.BlobTargetOption.encryptionKey(encryptionKey),
        precondition);

    System.out.println(
        "File "
            + filePath
            + " uploaded to bucket "
            + bucketName
            + " as "
            + objectName
            + " with supplied encryption key");
  }
}

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 path to your file to upload
// const filePath = 'path/to/your/file';

// The new ID for your GCS file
// const destFileName = 'your-new-file-name';

// The key to encrypt the object with
// const key = 'TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=';

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

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

async function uploadEncryptedFile() {
  const options = {
    destination: destFileName,
    encryptionKey: Buffer.from(key, 'base64'),

    // 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. For a destination
    // object that does not yet exist, set the ifGenerationMatch precondition to 0
    // If the destination object already exists in your bucket, set instead a
    // generation-match precondition using its generation number.
    preconditionOpts: {ifGenerationMatch: generationMatchPrecondition},
  };

  await storage.bucket(bucketName).upload(filePath, options);

  console.log(
    `File ${filePath} uploaded to gs://${bucketName}/${destFileName}`
  );
}

uploadEncryptedFile().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;

/**
 * Upload an encrypted file.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $objectName The name of your Cloud Storage object.
 *        (e.g. 'my-object')
 * @param string $source The path to the file to upload.
 *        (e.g. '/path/to/your/file')
 * @param string $base64EncryptionKey The base64 encoded encryption key.
 *        (e.g. 'TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=')
 */
function upload_encrypted_object(string $bucketName, string $objectName, string $source, string $base64EncryptionKey): void
{
    $storage = new StorageClient();
    $file = fopen($source, 'r');
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->upload($file, [
        'name' => $objectName,
        'encryptionKey' => $base64EncryptionKey,
    ]);
    printf('Uploaded encrypted %s to gs://%s/%s' . PHP_EOL,
        basename($source), $bucketName, $objectName);
}

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.

import base64

from google.cloud import storage


def upload_encrypted_blob(
    bucket_name,
    source_file_name,
    destination_blob_name,
    base64_encryption_key,
):
    """Uploads a file to a Google Cloud Storage bucket using a custom
    encryption key.

    The file will be encrypted by Google Cloud Storage and only
    retrievable using the provided encryption key.
    """
    # bucket_name = "your-bucket-name"
    # source_file_name = "local/path/to/file"
    # destination_blob_name = "storage-object-name"
    # base64_encryption_key = "TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g="

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

    # Encryption key must be an AES256 key represented as a bytestring with
    # 32 bytes. Since it's passed in as a base64 encoded string, it needs
    # to be decoded.
    encryption_key = base64.b64decode(base64_encryption_key)
    blob = bucket.blob(
        destination_blob_name, encryption_key=encryption_key
    )

    # 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. For a destination
    # object that does not yet exist, set the if_generation_match precondition to 0.
    # If the destination object already exists in your bucket, set instead a
    # generation-match precondition using its generation number.
    generation_match_precondition = 0

    blob.upload_from_filename(source_file_name, if_generation_match=generation_match_precondition)

    print(
        f"File {source_file_name} uploaded to {destination_blob_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 upload_encrypted_file bucket_name:, local_file_path:, file_name: nil, encryption_key:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  # The path to your file to upload
  # local_file_path = "/local/path/to/file.txt"

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

  # The key to encrypt the object with
  # encryption_key = "TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g="

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new

  bucket = storage.bucket bucket_name, skip_lookup: true

  file = bucket.create_file local_file_path, file_name, encryption_key: encryption_key

  puts "Uploaded #{file.name} with encryption key"
end

What's next

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