创建和验证 MAC 数字签名

本页介绍了如何基于 MAC 密钥创建和验证数字签名。

生产者和验证者共享一个密钥，用于根据输入数据计算 MAC 标记。MAC 标记可用作数字签名。验证者收到消息及其关联的 MAC 标记后，会根据消息内容生成自己的标记。然后，验证者可以将收到的标记与其生成的标记进行比较，以查看它们是否匹配。如果这两个标记匹配，验证者就会知道他们收到的消息与生产者签名的消息相同。

准备工作

• 创建 MAC 数字签名时，您必须使用密钥用途为 MAC 的密钥。在创建密钥时，请使用 MAC。

• 确保您要签名的文件不超出文件大小限制。使用 Cloud HSM 密钥时，您可以为的文件大小上限为 16 KiB。对于所有其他密钥，文件大小上限为 64 KiB。

所需的角色

如需获得创建和验证签名所需的权限，请让管理员向您授予密钥的以下 IAM 角色：

• 如需创建签名，请使用： Cloud KMS CryptoKey Signer (roles/cloudkms.signer)
• 如需验证签名，请使用： Cloud KMS CryptoKey Verifier (roles/cloudkms.verifier)
• 如需创建和验证签名，请使用： Cloud KMS CryptoKey Signer/Verifier (roles/cloudkms.signerVerifier)

如需详细了解如何授予角色，请参阅管理对项目、文件夹和组织的访问权限。

您也可以通过自定义角色或其他预定义角色来获取所需的权限。

注意 ：如果您要使用服务账号进行签名或验证，请向服务账号授予所需的角色。

创建 MAC 签名

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 mac-sign \
    --version KEY_VERSION \
    --key KEY_NAME \
    --keyring KEY_RING \
    --location LOCATION \
    --input-file INPUT_FILE_PATH \
    --signature-file SIGNED_FILE_PATH

替换以下内容：

• KEY_VERSION：密钥版本号。
• KEY_NAME：密钥的名称。
• KEY_RING：包含密钥的密钥环的名称。
• LOCATION：密钥环的 Cloud KMS 位置。
• INPUT_FILE_PATH：您要签名的文件的本地路径。
• SIGNED_FILE_PATH：您要保存生成的签名的本地路径。

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。

using Google.Cloud.Kms.V1;
using Google.Protobuf;

public class SignMacSample
{
    public byte[] SignMac(
      string projectId = "my-project", string locationId = "us-east1", string keyRingId = "my-key-ring", string keyId = "my-key", string keyVersionId = "123",
      string data = "Sample data")
    {
        // Create the client.
        KeyManagementServiceClient client = KeyManagementServiceClient.Create();

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

        // Convert the data into a ByteString.
        ByteString dataByteString = ByteString.CopyFromUtf8(data);

        // Call the API.
        MacSignResponse result = client.MacSign(keyVersionName, dataByteString);

        // The data comes back as raw bytes, which may include non-printable
        // characters. To print the result, you could encode it as base64.
        // string encodedSignature = result.Mac.ToBase64();

        // Get the signature.
        byte[] signature = result.Mac.ToByteArray();

        // Return the result.
        return signature;
    }
}

Go

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

import (
	"context"
	"encoding/base64"
	"fmt"
	"io"

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

// signMac will sign a plaintext message using the HMAC algorithm.
func signMac(w io.Writer, name string, data string) error {
	// name := "projects/my-project/locations/us-east1/keyRings/my-key-ring/cryptoKeys/my-key/cryptoKeyVersions/123"
	// data := "my data to sign"

	// 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.MacSignRequest{
		Name: name,
		Data: []byte(data),
	}

	// Generate HMAC of data.
	result, err := client.MacSign(ctx, req)
	if err != nil {
		return fmt.Errorf("failed to hmac sign: %w", err)
	}

	// The data comes back as raw bytes, which may include non-printable
	// characters. This base64-encodes the result so it can be printed below.
	encodedSignature := base64.StdEncoding.EncodeToString(result.Mac)

	fmt.Fprintf(w, "Signature: %s", encodedSignature)
	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。

import com.google.cloud.kms.v1.CryptoKeyVersionName;
import com.google.cloud.kms.v1.KeyManagementServiceClient;
import com.google.cloud.kms.v1.MacSignResponse;
import com.google.protobuf.ByteString;
import java.io.IOException;
import java.util.Base64;

public class SignMac {

  public void signMac() throws IOException {
    // 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";
    String data = "Data to sign";
    signMac(projectId, locationId, keyRingId, keyId, keyVersionId, data);
  }

  // Sign data with a given mac key.
  public void signMac(
      String projectId,
      String locationId,
      String keyRingId,
      String keyId,
      String keyVersionId,
      String data)
      throws IOException {
    // 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);

      // Generate an HMAC of the data.
      MacSignResponse response = client.macSign(keyVersionName, ByteString.copyFromUtf8(data));

      // The data comes back as raw bytes, which may include non-printable
      // characters. This base64-encodes the result so it can be printed below.
      String encodedSignature = Base64.getEncoder().encodeToString(response.getMac().toByteArray());
      System.out.printf("Signature: %s%n", encodedSignature);
    }
  }
}

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。

//
// TODO(developer): Uncomment these variables before running the sample.
//
// const projectId = 'your-project-id';
// const locationId = 'us-east1';
// const keyRingId = 'my-key-ring';
// const keyId = 'my-key';
// const versionId = '123';
// const data = Buffer.from('...');

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

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

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

async function signMac() {
  // Sign the data with Cloud KMS
  const [signResponse] = await client.macSign({
    name: versionName,
    data: data,
  });

  // Example of how to display signature. Because the signature is in a binary
  // format, you need to encode the output before printing it to a console or
  // displaying it on a screen.
  const encoded = signResponse.mac.toString('base64');
  console.log(`Signature: ${encoded}`);

  return signResponse;
}

return signMac();

Python

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

from google.cloud import kms


def sign_mac(
    project_id: str,
    location_id: str,
    key_ring_id: str,
    key_id: str,
    version_id: str,
    data: str,
) -> kms.MacSignResponse:
    """
    Sign a message using the private key part of 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): Version to use (e.g. '1').
        data (string): Data to sign.

    Returns:
        MacSignResponse: Signature.
    """

    # Import base64 for printing the ciphertext.
    import base64

    # 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
    )

    # Convert the message to bytes.
    data_bytes = data.encode("utf-8")

    # Call the API
    sign_response = client.mac_sign(
        request={"name": key_version_name, "data": data_bytes}
    )

    print(f"Signature: {base64.b64encode(sign_response.mac)!r}")
    return sign_response

Ruby

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

# 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"
# data        = "my data"

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

# Require digest.
require "digest"

# 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.
sign_response = client.mac_sign name: key_version_name, data: data

# The data comes back as raw bytes, which may include non-printable
# characters. This base64-encodes the result so it can be printed below.
encoded_signature = Base64.strict_encode64 sign_response.mac

puts "Signature: #{encoded_signature}"

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。

使用 CryptoKeyVersions.macSign 方法执行签名。此方法返回的响应包含 base64 编码的签名。

提示：您可以使用 Linux 或 macOS 上的 base64 命令或 Windows 上的 Base64.exe 命令对数据进行 base64 编码或解码。编程语言和脚本语言通常包含用于 base64 编码的库。如需查看命令行示例，请参阅 Cloud Vision API 文档中的 Base64 编码。

验证 MAC 签名

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 mac-verify \
    --version KEY_VERSION \
    --key KEY_NAME \
    --keyring KEY_RING \
    --location LOCATION \
    --input-file INPUT_FILE_PATH \
    --signature-file SIGNED_FILE_PATH

• KEY_VERSION：密钥版本号。
• KEY_NAME：密钥的名称。
• KEY_RING：包含密钥的密钥环的名称。
• LOCATION：密钥环的 Cloud KMS 位置。
• INPUT_FILE_PATH：已签名的文件的本地路径。
• SIGNED_FILE_PATH：要验证的签名文件的本地路径。

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。

using Google.Cloud.Kms.V1;
using Google.Protobuf;

public class VerifyMacSample
{
    public bool VerifyMac(
      string projectId = "my-project", string locationId = "us-east1", string keyRingId = "my-key-ring", string keyId = "my-key", string keyVersionId = "123",
      string data = "my data",
      byte[] signature = null)
    {
        // Build the key version name.
        CryptoKeyVersionName keyVersionName = new CryptoKeyVersionName(projectId, locationId, keyRingId, keyId, keyVersionId);

        // Create the client.
        KeyManagementServiceClient client = KeyManagementServiceClient.Create();

        // Convert the data and signatures into ByteStrings.
        ByteString dataByteString = ByteString.CopyFromUtf8(data);
        ByteString signatureByteString = ByteString.CopyFrom(signature);

        // Verify the signature.
        MacVerifyResponse result = client.MacVerify(keyVersionName, dataByteString, signatureByteString);

        // Return the result.
        return result.Success;
    }
}

Go

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

import (
	"context"
	"fmt"
	"io"

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

// verifyMac will verify a previous HMAC signature.
func verifyMac(w io.Writer, name string, data, signature []byte) error {
	// name := "projects/my-project/locations/us-east1/keyRings/my-key-ring/cryptoKeys/my-key/cryptoKeyVersions/123"
	// data := "my previous data"
	// signature := []byte("...")  // Response from a sign request

	// 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.MacVerifyRequest{
		Name: name,
		Data: data,
		Mac:  signature,
	}

	// Verify the signature.
	result, err := client.MacVerify(ctx, req)
	if err != nil {
		return fmt.Errorf("failed to verify signature: %w", err)
	}

	fmt.Fprintf(w, "Verified: %t", result.Success)
	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。

import com.google.cloud.kms.v1.CryptoKeyVersionName;
import com.google.cloud.kms.v1.KeyManagementServiceClient;
import com.google.cloud.kms.v1.MacVerifyResponse;
import com.google.protobuf.ByteString;
import java.io.IOException;

public class VerifyMac {

  public void verifyMac() throws IOException {
    // 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";
    String data = "Data to sign";
    byte[] signature = null;
    verifyMac(projectId, locationId, keyRingId, keyId, keyVersionId, data, signature);
  }

  // Sign data with a given mac key.
  public void verifyMac(
      String projectId,
      String locationId,
      String keyRingId,
      String keyId,
      String keyVersionId,
      String data,
      byte[] signature)
      throws IOException {
    // 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);

      // Verify the signature
      MacVerifyResponse response =
          client.macVerify(
              keyVersionName, ByteString.copyFromUtf8(data), ByteString.copyFrom(signature));

      // The data comes back as raw bytes, which may include non-printable
      // characters. This base64-encodes the result so it can be printed below.
      System.out.printf("Success: %s%n", response.getSuccess());
    }
  }
}

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。

//
// TODO(developer): Uncomment these variables before running the sample.
//
// const projectId = 'your-project-id';
// const locationId = 'us-east1';
// const keyRingId = 'my-key-ring';
// const keyId = 'my-key';
// const versionId = '123';
// const data = Buffer.from('...');
// const signature = Buffer.from('...');

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

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

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

async function verifyMac() {
  // Verify the data with Cloud KMS
  const [verifyResponse] = await client.macVerify({
    name: versionName,
    data: data,
    mac: signature,
  });

  console.log(`Verified: ${verifyResponse.success}`);
  return verifyResponse;
}

return verifyMac();

Python

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

from google.cloud import kms


def verify_mac(
    project_id: str,
    location_id: str,
    key_ring_id: str,
    key_id: str,
    version_id: str,
    data: str,
    signature: bytes,
) -> kms.MacVerifyResponse:
    """
    Verify the signature of data from an HMAC 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): Version to use (e.g. '1').
        data (string): Data that was signed.
        signature (bytes): Signature bytes.

    Returns:
        MacVerifyResponse: Success.
    """

    # 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
    )

    # Convert the message to bytes.
    data_bytes = data.encode("utf-8")

    # Call the API
    verify_response = client.mac_verify(
        request={"name": key_version_name, "data": data_bytes, "mac": signature}
    )

    print(f"Verified: {verify_response.success}")
    return verify_response

Ruby

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

# 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"
# data        = "my data"
# signature   = "..."

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

# Require digest.
require "digest"

# 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.
verify_response = client.mac_verify name: key_version_name, data: data, mac: signature
puts "Verified: #{verify_response.success}"

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。

使用 CryptoKeyVersions.macVerify 方法执行验证。要验证的签名应采用 base64 编码。此方法返回的响应包含布尔值，指示签名是否验证成功。

提示：您可以使用 Linux 或 macOS 上的 base64 命令或 Windows 上的 Base64.exe 命令对数据进行 base64 编码或解码。编程语言和脚本语言通常包含用于 base64 编码的库。如需查看命令行示例，请参阅 Cloud Vision API 文档中的 Base64 编码。