Mendownload objek yang dienkripsi CSEK

Download objek yang dienkripsi CSEK.

Jelajahi lebih lanjut

Untuk mengetahui dokumentasi mendetail yang menyertakan contoh kode ini, lihat referensi berikut:

Contoh kode

C++

Untuk informasi selengkapnya, lihat Dokumentasi referensi Cloud Storage C++ API.

Untuk melakukan autentikasi ke Cloud Storage, siapkan Kredensial Default Aplikasi. Untuk informasi selengkapnya, lihat Menyiapkan autentikasi untuk library klien. 

namespace gcs = ::google::cloud::storage;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name, std::string const& base64_aes256_key) {
  gcs::ObjectReadStream stream =
      client.ReadObject(bucket_name, object_name,
                        gcs::EncryptionKey::FromBase64Key(base64_aes256_key));

  std::string data(std::istreambuf_iterator<char>{stream}, {});
  if (stream.bad()) throw google::cloud::Status(stream.status());
  std::cout << "The object contents are: " << data << "\n";
}

C#

Untuk mengetahui informasi selengkapnya, lihatDokumentasi referensi Cloud Storage C# API.

Untuk melakukan autentikasi ke Cloud Storage, siapkan Kredensial Default Aplikasi. Untuk informasi selengkapnya, lihat Menyiapkan autentikasi untuk library klien. 


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

public class DownloadEncryptedFileSample
{
    public void DownloadEncryptedFile(
        string key = "3eFsTXPvqi3BpT2ipFCGirslh1Jgc6ikjoAu2oQ5JcI=",
        string bucketName = "your-unique-bucket-name",
        string objectName = "my-file-name",
        string localPath = "my-local-path/my-file-name")
    {
        var storage = StorageClient.Create();
        using var outputFile = File.OpenWrite(localPath);
        storage.DownloadObject(bucketName, objectName, outputFile, new DownloadObjectOptions
        {
            EncryptionKey = EncryptionKey.Create(Convert.FromBase64String(key))
        });
        Console.WriteLine($"Downloaded {objectName} to {localPath}.");
    }
}

Go

Untuk mengetahui informasi selengkapnya, lihatDokumentasi referensi Cloud Storage Go API.

Untuk melakukan autentikasi ke Cloud Storage, siapkan Kredensial Default Aplikasi. Untuk informasi selengkapnya, lihat Menyiapkan autentikasi untuk library klien. 

import (
	"context"
	"fmt"
	"io"
	"io/ioutil"
	"time"

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

// downloadEncryptedFile reads an encrypted object.
func downloadEncryptedFile(w io.Writer, bucket, object string, secretKey []byte) ([]byte, error) {
	// bucket := "bucket-name"
	// object := "object-name"
	// key := []byte("secret-encryption-key")
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

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

	ctx, cancel := context.WithTimeout(ctx, time.Second*50)
	defer cancel()

	rc, err := obj.Key(secretKey).NewReader(ctx)
	if err != nil {
		return nil, fmt.Errorf("Object(%q).Key(%q).NewReader: %w", object, secretKey, err)
	}
	defer rc.Close()

	data, err := ioutil.ReadAll(rc)
	if err != nil {
		return nil, fmt.Errorf("ioutil.ReadAll: %w", err)
	}
	fmt.Fprintf(w, "File %v downloaded with encryption key.\n", object)
	return data, nil
}

Java

Untuk mengetahui informasi selengkapnya, lihatDokumentasi referensi Cloud Storage Java API.

Untuk melakukan autentikasi ke Cloud Storage, siapkan Kredensial Default Aplikasi. Untuk informasi selengkapnya, lihat Menyiapkan autentikasi untuk library klien. 


import com.google.cloud.storage.Blob;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.io.IOException;
import java.nio.file.Path;

public class DownloadEncryptedObject {
  public static void downloadEncryptedObject(
      String projectId,
      String bucketName,
      String objectName,
      Path destFilePath,
      String decryptionKey)
      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 which the file should be downloaded
    // Path destFilePath = Paths.get("/local/path/to/file.txt");

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

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();

    Blob blob = storage.get(bucketName, objectName);
    blob.downloadTo(destFilePath, Blob.BlobSourceOption.decryptionKey(decryptionKey));

    System.out.println(
        "Downloaded object "
            + objectName
            + " from bucket name "
            + bucketName
            + " to "
            + destFilePath
            + " using customer-supplied encryption key");
  }
}

Node.js

Untuk mengetahui informasi selengkapnya, lihatDokumentasi referensi Cloud Storage Node.js API.

Untuk melakukan autentikasi ke Cloud Storage, siapkan Kredensial Default Aplikasi. Untuk informasi selengkapnya, lihat Menyiapkan autentikasi untuk library klien. 

/**
 * 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 srcFileName = 'your-file-name';

// The path to which the file should be downloaded
// const destFileName = '/local/path/to/file.txt';

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

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

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

async function downloadEncryptedFile() {
  const options = {
    destination: destFileName,
  };

  // Decrypts and downloads the file. This can only be done with the key used
  // to encrypt and upload the file.
  await storage
    .bucket(bucketName)
    .file(srcFileName)
    .setEncryptionKey(Buffer.from(encryptionKey, 'base64'))
    .download(options);

  console.log(`File ${srcFileName} downloaded to ${destFileName}`);
}

downloadEncryptedFile().catch(console.error);

PHP

Untuk mengetahui informasi selengkapnya, lihatDokumentasi referensi Cloud Storage PHP API.

Untuk melakukan autentikasi ke Cloud Storage, siapkan Kredensial Default Aplikasi. Untuk informasi selengkapnya, lihat Menyiapkan autentikasi untuk library klien. 

use Google\Cloud\Storage\StorageClient;

/**
 * Download 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 $destination The local destination to save the encrypted file.
 *        (e.g. '/path/to/your/file')
 * @param string $base64EncryptionKey The base64 encoded encryption key. Should
 *        (e.g. 'TIbv/fjexq+VmtXzAlc63J4z5kFmWJ6NdAPQulQBT7g=')
 *     be the same key originally used to encrypt the object.
 */
function download_encrypted_object(string $bucketName, string $objectName, string $destination, string $base64EncryptionKey): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $object->downloadToFile($destination, [
        'encryptionKey' => $base64EncryptionKey,
    ]);
    printf('Encrypted object gs://%s/%s downloaded to %s' . PHP_EOL,
        $bucketName, $objectName, basename($destination));
}

Python

Untuk mengetahui informasi selengkapnya, lihatDokumentasi referensi Cloud Storage Python API.

Untuk melakukan autentikasi ke Cloud Storage, siapkan Kredensial Default Aplikasi. Untuk informasi selengkapnya, lihat Menyiapkan autentikasi untuk library klien. 

import base64

from google.cloud import storage


def download_encrypted_blob(
    bucket_name,
    source_blob_name,
    destination_file_name,
    base64_encryption_key,
):
    """Downloads a previously-encrypted blob from Google Cloud Storage.

    The encryption key provided must be the same key provided when uploading
    the blob.
    """
    # bucket_name = "your-bucket-name"
    # source_blob_name = "storage-object-name"
    # destination_file_name = "local/path/to/file"
    # base64_encryption_key = "base64-encoded-encryption-key"

    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(source_blob_name, encryption_key=encryption_key)

    blob.download_to_filename(destination_file_name)

    print(
        f"Blob {source_blob_name} downloaded to {destination_file_name}."
    )

Ruby

Untuk mengetahui informasi selengkapnya, lihatDokumentasi referensi Cloud Storage Ruby API.

Untuk melakukan autentikasi ke Cloud Storage, siapkan Kredensial Default Aplikasi. Untuk informasi selengkapnya, lihat Menyiapkan autentikasi untuk library klien. 

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

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

  # The path to which the file should be downloaded
  # local_file_path = "/local/path/to/file.txt"

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

  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.download local_file_path, encryption_key: encryption_key

  puts "Downloaded encrypted #{file.name} to #{local_file_path}"
end

Langkah selanjutnya

Untuk menelusuri dan memfilter contoh kode untuk produk Google Cloud lainnya, lihat browser contoh Google Cloud.