检索公钥

您可以使用 Google Cloud Console、Google Cloud CLI 和 Cloud Key Management Service API 检索非对称密钥版本的公钥部分。

公钥采用隐私权保密增强电子邮件 (PEM) 格式。如需了解详情，请参阅 RFC 7468 部分中的一般注意事项和主体公钥信息的文本编码。

将检索公钥的用户或服务需要具有密钥版本的 cloudkms.cryptoKeyVersions.viewPublicKey 权限。您可以参阅权限和角色，了解 Cloud KMS 测试版中的权限。

要下载现有非对称密钥版本的公钥，请执行以下操作：

控制台

1. 转到 Google Cloud 控制台中的密钥管理页面。

   转到“密钥管理”页面

2. 点击包含您要检索公钥的非对称密钥的密钥环的名称。

3. 点击要检索公钥的密钥的名称。

4. 在与要检索公钥的密钥版本对应的行中，点击查看更多 。

5. 点击获取公钥。

6. 公钥显示在提示中。您可以将公钥复制到剪贴板。要下载公钥，请点击下载。

如果您没有看到获取公钥选项，请验证密钥是否为非对称密钥，以及您是否拥有 cloudkms.cryptoKeyVersions.viewPublicKey 权限。

从 Google Cloud Console 下载的公钥的文件名格式如下：

[key-ring]-[key-name]-[key-version].pub

文件名的每个部分由连字符分隔。

gcloud

如需在命令行上使用 Cloud KMS，请先安装或升级到最新版本的 Google Cloud CLI。

gcloud kms keys versions get-public-key key-version \
    --key key \
    --keyring key-ring-name \
    --location location \
    --output-file public-key.pub

将 key-version 替换为密钥版本。将 key 替换为密钥的名称。将 key-ring 替换为存储密钥的密钥环的名称。将 location 替换为密钥环的 Cloud KMS 位置。将 public-key.pub 替换为要保存公钥的文件路径。

如需了解所有标志和可能值，请使用 --help 标志运行命令。

C#

要运行此代码，请先设置 C# 开发环境并安装 Cloud KMS C# SDK。

在 GitHub 上查看 反馈

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

要运行此代码，请先设置 Go 开发环境并安装 Cloud KMS Go SDK。

在 GitHub 上查看 反馈

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

	kms "cloud.google.com/go/kms/apiv1"
	kmspb "google.golang.org/genproto/googleapis/cloud/kms/v1"
)

// 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: %v", 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: %v", 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: %v", err)
	}
	fmt.Fprintf(w, "Retrieved public key: %v\n", publicKey)
	return nil
}

Java

要运行此代码，请先设置 Java 开发环境并安装 Cloud KMS Java SDK。

在 GitHub 上查看 反馈

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

要运行此代码，请先设置 Node.js 开发环境并安装 Cloud KMS Node.js SDK。

在 GitHub 上查看 反馈

//
// 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

要运行此代码，请先了解如何在 Google Cloud 上使用 PHP 并安装 Cloud KMS PHP SDK。

在 GitHub 上查看 反馈

use Google\Cloud\Kms\V1\KeyManagementServiceClient;

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.
    $publicKey = $client->getPublicKey($keyVersionName);
    printf('Public key: %s' . PHP_EOL, $publicKey->getPem());

    return $publicKey;
}

Python

要运行此代码，请先设置 Python 开发环境并安装 Cloud KMS Python SDK。

在 GitHub 上查看 反馈

def get_public_key(project_id, location_id, key_ring_id, key_id, version_id):
    """
    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.

    """

    # Import the client library.
    from google.cloud import kms

    # 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):
        raise Exception('The response received from the server was corrupted in-transit.')
    # End integrity verification

    print('Public key: {}'.format(public_key.pem))
    return public_key

def crc32c(data):
    """
    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
    import six
    crc32c_fun = crcmod.predefined.mkPredefinedCrcFun('crc-32c')
    return crc32c_fun(six.ensure_binary(data))

Ruby

要运行此代码，请先设置 Ruby 开发环境并安装 Cloud KMS Ruby SDK。

在 GitHub 上查看 反馈

# 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

这些示例使用 curl 作为 HTTP 客户端来演示如何使用 API。如需详细了解访问权限控制，请参阅访问 Cloud KMS API。

通过调用 CryptoKeyVersions.getPublicKey 方法检索公钥。

curl "https://cloudkms.googleapis.com/v1/projects/project-id/locations/location-id/keyRings/key-ring-id/cryptoKeys/crypto-key-id/cryptoKeyVersions/version-id/publicKey" \
    --request "GET" \
    --header "authorization: Bearer token"