Mengambil kunci publik

Halaman ini menunjukkan cara mengambil bagian kunci publik dari versi kunci asimetris yang diaktifkan.

Kunci publik menggunakan format Privacy-Enhanced Electronic Mail (PEM). Untuk informasi selengkapnya, lihat bagian RFC 7468 untuk Pertimbangan Umum dan Encoding Teks pada Info Kunci Publik Subjek.

Peran yang diperlukan

Untuk mendapatkan izin yang diperlukan untuk mengambil kunci publik, mintalah administrator untuk memberi Anda peran IAM Cloud KMS CryptoKey Public Key Viewer (roles/cloudkms.publicKeyViewer) pada kunci Anda atau resource induk. Untuk mengetahui informasi selengkapnya tentang cara memberikan peran, lihat Mengelola akses.

Peran yang telah ditetapkan ini berisi izin yang diperlukan untuk mengambil kunci publik. Untuk melihat izin yang benar-benar diperlukan, perluas bagian Izin yang diperlukan:

Izin yang diperlukan

Izin berikut diperlukan untuk mengambil kunci publik:

• cloudkms.cryptoKeyVersions.viewPublicKey
• cloudkms.locations.get
• cloudkms.locations.list
• resourcemanager.projects.get

Anda mung juga bisa mendapatkan izin ini dengan peran khusus atau peran bawaanlainnya.

Mengambil kunci publik

Untuk mendownload kunci publik versi kunci asimetris yang diaktifkan:

Konsol

1. Di konsol Google Cloud, buka halaman Key Management.

   Buka Key Management

2. Klik nama key ring yang berisi kunci asimetris yang ingin Anda ambil kunci publiknya.

3. Klik nama kunci yang ingin Anda ambil kunci publiknya.

4. Di baris yang sesuai dengan versi kunci yang ingin Anda ambil kunci publiknya, klik View More .

5. Klik Dapatkan kunci publik.

6. Kunci publik akan ditampilkan dalam perintah. Anda dapat menyalin kunci publik ke {i>clipboard<i} Anda. Untuk mendownload kunci publik, klik Download.

Jika Anda tidak melihat opsi Dapatkan kunci publik, pastikan hal berikut:

• Kuncinya adalah kunci asimetris.
• Versi kunci diaktifkan.
• Anda memiliki izin cloudkms.cryptoKeyVersions.viewPublicKey.

Nama file kunci publik yang didownload dari Google Cloud Console berbentuk:

KEY_RING-KEY_NAME-KEY_VERSION.pub

Setiap bagian nama file dipisahkan dengan tanda hubung, misalnya ringname-keyname-version.pub

gcloud

Untuk menggunakan Cloud KMS di command line, Instal atau upgrade Google Cloud CLI ke versi terbaru terlebih dahulu.

Catatan: Perintah gcloud kms keys versions get-public-key harus dijalankan dari shell lokal. Jangan mencoba menjalankan perintah ini menggunakan Cloud Shell.

gcloud kms keys versions get-public-key KEY_VERSION \
    --key KEY_NAME \
    --keyring KEY_RING \
    --location LOCATION \
    --output-file OUTPUT_FILE_PATH

Ganti kode berikut:

• KEY_VERSION: nomor versi kunci.
• KEY_NAME: nama kunci.
• KEY_RING: nama key ring yang berisi kunci.
• LOCATION: lokasi Cloud KMS key ring.
• OUTPUT_FILE_PATH: jalur tempat Anda ingin menyimpan file kunci publik, misalnya, public-key.pub.

Untuk mengetahui informasi tentang semua tanda dan nilai yang memungkinkan, jalankan perintah dengan tanda --help.

C#

Untuk menjalankan kode ini, siapkan lingkungan pengembangan C# terlebih dahulu lalu instal Cloud KMS C# SDK.

using Google.Cloud.Kms.V1;

public class GetPublicKeySample
{
    public PublicKey GetPublicKey(string projectId = "my-project", string locationId = "us-east1", string keyRingId = "my-key-ring", string keyId = "my-key", string keyVersionId = "123")
    {
        // Create the client.
        KeyManagementServiceClient client = KeyManagementServiceClient.Create();

        // Build the key version name.
        CryptoKeyVersionName keyVersionName = new CryptoKeyVersionName(projectId, locationId, keyRingId, keyId, keyVersionId);

        // Call the API.
        PublicKey result = client.GetPublicKey(keyVersionName);

        // Return the ciphertext.
        return result;
    }
}

Go

Untuk menjalankan kode ini, siapkan lingkungan pengembangan Go terlebih dahulu lalu instal Cloud KMS Go SDK.

import (
	"context"
	"crypto/x509"
	"encoding/pem"
	"fmt"
	"hash/crc32"
	"io"

	kms "cloud.google.com/go/kms/apiv1"
	"cloud.google.com/go/kms/apiv1/kmspb"
)

// getPublicKey retrieves the public key from an asymmetric key pair on
// Cloud KMS.
func getPublicKey(w io.Writer, name string) error {
	// name := "projects/my-project/locations/us-east1/keyRings/my-key-ring/cryptoKeys/my-key/cryptoKeyVersions/123"

	// Create the client.
	ctx := context.Background()
	client, err := kms.NewKeyManagementClient(ctx)
	if err != nil {
		return fmt.Errorf("failed to create kms client: %w", err)
	}
	defer client.Close()

	// Build the request.
	req := &kmspb.GetPublicKeyRequest{
		Name: name,
	}

	// Call the API.
	result, err := client.GetPublicKey(ctx, req)
	if err != nil {
		return fmt.Errorf("failed to get public key: %w", err)
	}

	// The 'Pem' field is the raw string representation of the public key.
	// Convert 'Pem' into bytes for further processing.
	key := []byte(result.Pem)

	// Optional, but recommended: perform integrity verification on result.
	// For more details on ensuring E2E in-transit integrity to and from Cloud KMS visit:
	// https://cloud.google.com/kms/docs/data-integrity-guidelines
	crc32c := func(data []byte) uint32 {
		t := crc32.MakeTable(crc32.Castagnoli)
		return crc32.Checksum(data, t)
	}
	if int64(crc32c(key)) != result.PemCrc32C.Value {
		return fmt.Errorf("getPublicKey: response corrupted in-transit")
	}

	// Optional - parse the public key. This transforms the string key into a Go
	// PublicKey.
	block, _ := pem.Decode(key)
	publicKey, err := x509.ParsePKIXPublicKey(block.Bytes)
	if err != nil {
		return fmt.Errorf("failed to parse public key: %w", err)
	}
	fmt.Fprintf(w, "Retrieved public key: %v\n", publicKey)
	return nil
}

Java

Untuk menjalankan kode ini, siapkan lingkungan pengembangan Java terlebih dahulu dan instal Java SDK Cloud KMS.

import com.google.cloud.kms.v1.CryptoKeyVersionName;
import com.google.cloud.kms.v1.KeyManagementServiceClient;
import com.google.cloud.kms.v1.PublicKey;
import java.io.IOException;
import java.security.GeneralSecurityException;

public class GetPublicKey {

  public void getPublicKey() throws IOException, GeneralSecurityException {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "your-project-id";
    String locationId = "us-east1";
    String keyRingId = "my-key-ring";
    String keyId = "my-key";
    String keyVersionId = "123";
    getPublicKey(projectId, locationId, keyRingId, keyId, keyVersionId);
  }

  // Get the public key associated with an asymmetric key.
  public void getPublicKey(
      String projectId, String locationId, String keyRingId, String keyId, String keyVersionId)
      throws IOException, GeneralSecurityException {
    // Initialize client that will be used to send requests. This client only
    // needs to be created once, and can be reused for multiple requests. After
    // completing all of your requests, call the "close" method on the client to
    // safely clean up any remaining background resources.
    try (KeyManagementServiceClient client = KeyManagementServiceClient.create()) {
      // Build the key version name from the project, location, key ring, key,
      // and key version.
      CryptoKeyVersionName keyVersionName =
          CryptoKeyVersionName.of(projectId, locationId, keyRingId, keyId, keyVersionId);

      // Get the public key.
      PublicKey publicKey = client.getPublicKey(keyVersionName);
      System.out.printf("Public key: %s%n", publicKey.getPem());
    }
  }
}

Node.js

Untuk menjalankan kode ini, siapkan lingkungan pengembangan Node.js terlebih dahulu, lalu instal Node.js SDK Cloud KMS.

//
// TODO(developer): Uncomment these variables before running the sample.
//
// const projectId = 'my-project';
// const locationId = 'us-east1';
// const keyRingId = 'my-key-ring';
// const keyId = 'my-key';

// Imports the Cloud KMS library
const {KeyManagementServiceClient} = require('@google-cloud/kms');

// Instantiates a client
const client = new KeyManagementServiceClient();

// Build the key version name
const versionName = client.cryptoKeyVersionPath(
  projectId,
  locationId,
  keyRingId,
  keyId,
  versionId
);

async function getPublicKey() {
  const [publicKey] = await client.getPublicKey({
    name: versionName,
  });

  // Optional, but recommended: perform integrity verification on publicKey.
  // For more details on ensuring E2E in-transit integrity to and from Cloud KMS visit:
  // https://cloud.google.com/kms/docs/data-integrity-guidelines
  const crc32c = require('fast-crc32c');
  if (publicKey.name !== versionName) {
    throw new Error('GetPublicKey: request corrupted in-transit');
  }
  if (crc32c.calculate(publicKey.pem) !== Number(publicKey.pemCrc32c.value)) {
    throw new Error('GetPublicKey: response corrupted in-transit');
  }

  console.log(`Public key pem: ${publicKey.pem}`);

  return publicKey;
}

return getPublicKey();

PHP

Untuk menjalankan kode ini, pelajari cara menggunakan PHP di Google Cloud terlebih dahulu dan instal PHP SDK Cloud KMS.

use Google\Cloud\Kms\V1\Client\KeyManagementServiceClient;
use Google\Cloud\Kms\V1\GetPublicKeyRequest;

function get_public_key(
    string $projectId = 'my-project',
    string $locationId = 'us-east1',
    string $keyRingId = 'my-key-ring',
    string $keyId = 'my-key',
    string $versionId = '123'
) {
    // Create the Cloud KMS client.
    $client = new KeyManagementServiceClient();

    // Build the key version name.
    $keyVersionName = $client->cryptoKeyVersionName($projectId, $locationId, $keyRingId, $keyId, $versionId);

    // Call the API.
    $getPublicKeyRequest = (new GetPublicKeyRequest())
        ->setName($keyVersionName);
    $publicKey = $client->getPublicKey($getPublicKeyRequest);
    printf('Public key: %s' . PHP_EOL, $publicKey->getPem());

    return $publicKey;
}

Python

Untuk menjalankan kode ini, siapkan lingkungan pengembangan Python terlebih dahulu lalu instal Cloud KMS Python SDK.

from google.cloud import kms

def get_public_key(
    project_id: str, location_id: str, key_ring_id: str, key_id: str, version_id: str
) -> kms.PublicKey:
    """
    Get the public key for an asymmetric key.

    Args:
        project_id (string): Google Cloud project ID (e.g. 'my-project').
        location_id (string): Cloud KMS location (e.g. 'us-east1').
        key_ring_id (string): ID of the Cloud KMS key ring (e.g. 'my-key-ring').
        key_id (string): ID of the key to use (e.g. 'my-key').
        version_id (string): ID of the key to use (e.g. '1').

    Returns:
        PublicKey: Cloud KMS public key response.

    """

    # Create the client.
    client = kms.KeyManagementServiceClient()

    # Build the key version name.
    key_version_name = client.crypto_key_version_path(
        project_id, location_id, key_ring_id, key_id, version_id
    )

    # Call the API.
    public_key = client.get_public_key(request={"name": key_version_name})

    # Optional, but recommended: perform integrity verification on public_key.
    # For more details on ensuring E2E in-transit integrity to and from Cloud KMS visit:
    # https://cloud.google.com/kms/docs/data-integrity-guidelines
    if not public_key.name == key_version_name:
        raise Exception("The request sent to the server was corrupted in-transit.")
    # See crc32c() function defined below.
    if not public_key.pem_crc32c == crc32c(public_key.pem.encode("utf-8")):
        raise Exception(
            "The response received from the server was corrupted in-transit."
        )
    # End integrity verification

    print(f"Public key: {public_key.pem}")
    return public_key

def crc32c(data: bytes) -> int:
    """
    Calculates the CRC32C checksum of the provided data.
    Args:
        data: the bytes over which the checksum should be calculated.
    Returns:
        An int representing the CRC32C checksum of the provided bytes.
    """
    import crcmod  # type: ignore

    crc32c_fun = crcmod.predefined.mkPredefinedCrcFun("crc-32c")
    return crc32c_fun(data)

Ruby

Untuk menjalankan kode ini, siapkan lingkungan pengembangan Ruby terlebih dahulu dan instal Ruby SDK Cloud KMS.

# TODO(developer): uncomment these values before running the sample.
# project_id  = "my-project"
# location_id = "us-east1"
# key_ring_id = "my-key-ring"
# key_id      = "my-key"
# version_id  = "123"

# Require the library.
require "google/cloud/kms"

# Create the client.
client = Google::Cloud::Kms.key_management_service

# Build the key version name.
key_version_name = client.crypto_key_version_path project:            project_id,
                                                  location:           location_id,
                                                  key_ring:           key_ring_id,
                                                  crypto_key:         key_id,
                                                  crypto_key_version: version_id

# Call the API.
public_key = client.get_public_key name: key_version_name
puts "Public key: #{public_key.pem}"

API

Contoh ini menggunakan curl sebagai klien HTTP untuk menunjukkan penggunaan API. Untuk informasi selengkapnya tentang kontrol akses, lihat Mengakses Cloud KMS API.

Ambil kunci publik dengan memanggil metode CryptoKeyVersions.getPublicKey.

curl "https://cloudkms.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/keyRings/KEY_RING/cryptoKeys/KEY_NAME/cryptoKeyVersions/KEY_VERSION/publicKey" \
    --request "GET" \
    --header "authorization: Bearer TOKEN"

Ganti kode berikut:

• PROJECT_ID: ID project yang berisi key ring.
• LOCATION: lokasi Cloud KMS key ring.
• KEY_RING: nama key ring yang berisi kunci.
• KEY_NAME: nama kunci.
• KEY_VERSION: nomor versi kunci.

Output-nya akan terlihat seperti berikut:

{
  "pem": "-----BEGIN PUBLIC KEY-----\nQ29uZ3JhdHVsYXRpb25zLCB5b3UndmUgZGlzY292ZX
          JlZCB0aGF0IHRoaXMgaXNuJ3QgYWN0dWFsbHkgYSBwdWJsaWMga2V5ISBIYXZlIGEgbmlj
          ZSBkYXkgOik=\n-----END PUBLIC KEY-----\n",
  "algorithm": "ALGORITHM",
  "pemCrc32c": "2561089887",
  "name": "projects/PROJECT_ID/locations/LOCATION/keyRings/
           KEY_RING/cryptoKeys/KEY_NAME/cryptoKeyVersions/
           KEY_VERSION",
  "protectionLevel": "SOFTWARE"
}