Re-encrypting data

This topic shows how to re-encrypt data using a Cloud Key Management Service symmetric key. You can adapt these examples for asymmetric keys. If you suspect unauthorized use of a key, you should re-encrypt the data protected by that key and then disable or schedule destruction of the prior key version.

Before you begin

This scenario requires the following conditions.

  • You have already encrypted data using Cloud KMS.

  • The key version used for the encryption is not disabled, scheduled for destruction, or destroyed. You use this key version to decrypt the encrypted data.

  • You have already rotated keys. A key rotation creates a new primary key version. You use the new primary key version to re-encrypt the data.

Re-encrypting data using asymmetric keys

The examples in this topic show how to re-encrypt data using a symmetric key. When you use a symmetric key, Cloud KMS automatically infers the key version to use for decryption. When you use an asymmetric key, you must specify the key version.

The workflow for re-encrypting data with asymmetric keys is similar to the one described in this topic.

Re-encrypting data workflow

Use the following steps to re-encrypt data and disable or schedule destruction of the key version used for the original encryption.

  1. Decrypt the data using the prior key version

  2. Re-encrypt the data using the new primary key version

  3. Disable or schedule destruction of the prior key version

Decrypt the data using the prior key version

Cloud KMS automatically uses the correct key version to decrypt data, as long as the key version is not disabled, scheduled for destruction, or destroyed. The following examples show how to decrypt the data. This is the same decryption code used in Encrypting and Decrypting.

Command-line

To use Cloud KMS on the command line, first Install or upgrade to the latest version of Cloud SDK.

gcloud kms decrypt \
    --key key \
    --keyring key-ring \
    --location location  \
    --ciphertext-file file-path-with-encrypted-data \
    --plaintext-file file-path-to-store-plaintext

Replace key with the name of the key to use for decryption. Replace key-ring with the name of the key ring where the key will be located. Replace location with the Cloud KMS location for the key ring. Replace file-path-with-encrypted-data and file-path-to-store-plaintext with the local file paths for reading the encrypted data and saving the decrypted output.

For information on all flags and possible values, run the command with the --help flag.

C#

To run this code, first set up a C# development environment and install the Cloud KMS C# SDK.


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

public class DecryptSymmetricSample
{
    public string DecryptSymmetric(
      string projectId = "my-project", string locationId = "us-east1", string keyRingId = "my-key-ring", string keyId = "my-key",
      byte[] ciphertext = null)
    {
        // Create the client.
        KeyManagementServiceClient client = KeyManagementServiceClient.Create();

        // Build the key name.
        CryptoKeyName keyName = new CryptoKeyName(projectId, locationId, keyRingId, keyId);

        // Call the API.
        DecryptResponse result = client.Decrypt(keyName, ByteString.CopyFrom(ciphertext));

        // Get the plaintext. Cryptographic plaintexts and ciphertexts are
        // always byte arrays.
        byte[] plaintext = result.Plaintext.ToByteArray();

        // Return the result.
        return Encoding.UTF8.GetString(plaintext);
    }
}

Go

To run this code, first set up a Go development environment and install the Cloud KMS Go SDK.

import (
	"context"
	"fmt"
	"io"

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

// decryptSymmetric will decrypt the input ciphertext bytes using the specified symmetric key.
func decryptSymmetric(w io.Writer, name string, ciphertext []byte) error {
	// name := "projects/my-project/locations/us-east1/keyRings/my-key-ring/cryptoKeys/my-key"
	// ciphertext := []byte("...")  // result of a symmetric encryption call

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

	// Build the request.
	req := &kmspb.DecryptRequest{
		Name:       name,
		Ciphertext: ciphertext,
	}

	// Call the API.
	result, err := client.Decrypt(ctx, req)
	if err != nil {
		return fmt.Errorf("failed to decrypt ciphertext: %v", err)
	}
	fmt.Fprintf(w, "Decrypted plaintext: %s", result.Plaintext)
	return nil
}

Java

To run this code, first set up a Java development environment and install the Cloud KMS Java SDK.

import com.google.cloud.kms.v1.CryptoKeyName;
import com.google.cloud.kms.v1.DecryptResponse;
import com.google.cloud.kms.v1.KeyManagementServiceClient;
import com.google.protobuf.ByteString;
import java.io.IOException;

public class DecryptSymmetric {

  public void decryptSymmetric() 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";
    byte[] ciphertext = null;
    decryptSymmetric(projectId, locationId, keyRingId, keyId, ciphertext);
  }

  // Decrypt data that was encrypted using a symmetric key.
  public void decryptSymmetric(
      String projectId, String locationId, String keyRingId, String keyId, byte[] ciphertext)
      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, and
      // key.
      CryptoKeyName keyName = CryptoKeyName.of(projectId, locationId, keyRingId, keyId);

      // Decrypt the response.
      DecryptResponse response = client.decrypt(keyName, ByteString.copyFrom(ciphertext));
      System.out.printf("Plaintext: %s%n", response.getPlaintext().toStringUtf8());
    }
  }
}

Node.js

To run this code, first set up a Node.js development environment and install the Cloud KMS Node.js SDK.

//
// 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';
// const ciphertext = Buffer.from('...');

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

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

// Build the key name
const keyName = client.cryptoKeyPath(projectId, locationId, keyRingId, keyId);

async function decryptSymmetric() {
  const [result] = await client.decrypt({
    name: keyName,
    ciphertext: ciphertext,
  });

  const plaintext = result.plaintext.toString('utf8');

  console.log(`Plaintext: ${plaintext}`);
  return plaintext;
}

return decryptSymmetric();

PHP

To run this code, first learn about using PHP on Google Cloud and install the Cloud KMS PHP SDK.

use Google\Cloud\Kms\V1\KeyManagementServiceClient;

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

    // Build the key name.
    $keyName = $client->cryptoKeyName($projectId, $locationId, $keyRingId, $keyId);

    // Call the API.
    $decryptResponse = $client->decrypt($keyName, $ciphertext);
    printf('Plaintext: %s' . PHP_EOL, $decryptResponse->getPlaintext());
    return $decryptResponse;
}

Python

To run this code, first set up a Python development environment and install the Cloud KMS Python SDK.

def decrypt_symmetric(project_id, location_id, key_ring_id, key_id, ciphertext):
    """
    Decrypt the ciphertext using the symmetric 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').
        ciphertext (bytes): Encrypted bytes to decrypt.

    Returns:
        DecryptResponse: Response including plaintext.

    """

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

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

    # Build the key name.
    key_name = client.crypto_key_path(project_id, location_id, key_ring_id, key_id)

    # Call the API.
    decrypt_response = client.decrypt(request={'name': key_name, 'ciphertext': ciphertext})
    print('Plaintext: {}'.format(decrypt_response.plaintext))
    return decrypt_response

Ruby

To run this code, first set up a Ruby development environment and install the 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"
# ciphertext  = "..."

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

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

# Build the parent key name.
key_name = client.crypto_key_path project:    project_id,
                                  location:   location_id,
                                  key_ring:   key_ring_id,
                                  crypto_key: key_id

# Call the API.
response = client.decrypt name: key_name, ciphertext: ciphertext
puts "Plaintext: #{response.plaintext}"

API

These examples use curl as an HTTP client to demonstrate using the API. For more information about access control, see Accessing the Cloud KMS API.

Decrypted text that is returned in the JSON from Cloud KMS is base64-encoded.

To decrypt encrypted data, make a POST request and provide the appropriate project and key information and specify the encrypted (cipher) text to be decrypted in the ciphertext field of the request body.

curl "https://cloudkms.googleapis.com/v1/projects/project-id/locations/location/keyRings/key-ring-name/cryptoKeys/key-name:decrypt" \
  --request "POST" \
  --header "authorization: Bearer token" \
  --header "content-type: application/json" \
  --data "{\"ciphertext\": \"encrypted-content\"}"

Here is an example payload with base64-encoded data:

{
  "ciphertext": "CiQAhMwwBo61cHas7dDgifrUFs5zNzBJ2uZtVFq4ZPEl6fUVT4kSmQ...",
}

Re-encrypt the data using the new primary key version

Cloud KMS automatically uses the new primary key version to encrypt data. The following examples show how to encrypt the data. This is the same encryption code used in Encrypting and Decrypting.

Command-line

To use Cloud KMS on the command line, first Install or upgrade to the latest version of Cloud SDK.

gcloud kms encrypt \
    --key key \
    --keyring key-ring \
    --location location  \
    --plaintext-file file-with-data-to-encrypt \
    --ciphertext-file file-to-store-encrypted-data

Replace key with the name of the key to use for encryption. Replace key-ring with the name of the key ring where the key is located. Replace location with the Cloud KMS location the key ring. Replace file-with-data-to-encrypt and file-to-store-encrypted-data with the local file paths for reading the plaintext data and saving the encrypted output.

For information on all flags and possible values, run the command with the --help flag.

C#

To run this code, first set up a C# development environment and install the Cloud KMS C# SDK.


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

public class EncryptSymmetricSample
{
    public byte[] EncryptSymmetric(
      string projectId = "my-project", string locationId = "us-east1", string keyRingId = "my-key-ring", string keyId = "my-key",
      string message = "Sample message")
    {
        // Create the client.
        KeyManagementServiceClient client = KeyManagementServiceClient.Create();

        // Build the key name.
        CryptoKeyName keyName = new CryptoKeyName(projectId, locationId, keyRingId, keyId);

        // Convert the message into bytes. Cryptographic plaintexts and
        // ciphertexts are always byte arrays.
        byte[] plaintext = Encoding.UTF8.GetBytes(message);

        // Call the API.
        EncryptResponse result = client.Encrypt(keyName, ByteString.CopyFrom(plaintext));

        // Return the ciphertext.
        return result.Ciphertext.ToByteArray();
    }
}

Go

To run this code, first set up a Go development environment and install the Cloud KMS Go SDK.

import (
	"context"
	"fmt"
	"io"

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

// encryptSymmetric encrypts the input plaintext with the specified symmetric
// Cloud KMS key.
func encryptSymmetric(w io.Writer, name string, message string) error {
	// name := "projects/my-project/locations/us-east1/keyRings/my-key-ring/cryptoKeys/my-key"
	// message := "Sample message"

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

	// Convert the message into bytes. Cryptographic plaintexts and
	// ciphertexts are always byte arrays.
	plaintext := []byte(message)

	// Build the request.
	req := &kmspb.EncryptRequest{
		Name:      name,
		Plaintext: plaintext,
	}

	// Call the API.
	result, err := client.Encrypt(ctx, req)
	if err != nil {
		return fmt.Errorf("failed to encrypt: %v", err)
	}

	fmt.Fprintf(w, "Encrypted ciphertext: %s", result.Ciphertext)
	return nil
}

Java

To run this code, first set up a Java development environment and install the Cloud KMS Java SDK.

import com.google.cloud.kms.v1.CryptoKeyName;
import com.google.cloud.kms.v1.EncryptResponse;
import com.google.cloud.kms.v1.KeyManagementServiceClient;
import com.google.protobuf.ByteString;
import java.io.IOException;

public class EncryptSymmetric {

  public void encryptSymmetric() 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 plaintext = "Plaintext to encrypt";
    encryptSymmetric(projectId, locationId, keyRingId, keyId, plaintext);
  }

  // Encrypt data with a given key.
  public void encryptSymmetric(
      String projectId, String locationId, String keyRingId, String keyId, String plaintext)
      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.
      CryptoKeyName keyVersionName = CryptoKeyName.of(projectId, locationId, keyRingId, keyId);

      // Encrypt the plaintext.
      EncryptResponse response = client.encrypt(keyVersionName, ByteString.copyFromUtf8(plaintext));
      System.out.printf("Ciphertext: %s%n", response.getCiphertext().toStringUtf8());
    }
  }
}

Node.js

To run this code, first set up a Node.js development environment and install the Cloud KMS Node.js SDK.

//
// 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';
// const plaintextBuffer = Buffer.from('...');

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

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

// Build the key name
const keyName = client.cryptoKeyPath(projectId, locationId, keyRingId, keyId);

async function encryptSymmetric() {
  const [encryptResponse] = await client.encrypt({
    name: keyName,
    plaintext: plaintextBuffer,
  });

  const ciphertext = encryptResponse.ciphertext;

  console.log(`Ciphertext: ${ciphertext.toString('base64')}`);
  return ciphertext;
}

return encryptSymmetric();

PHP

To run this code, first learn about using PHP on Google Cloud and install the Cloud KMS PHP SDK.

use Google\Cloud\Kms\V1\KeyManagementServiceClient;

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

    // Build the key name.
    $keyName = $client->cryptoKeyName($projectId, $locationId, $keyRingId, $keyId);

    // Call the API.
    $encryptResponse = $client->encrypt($keyName, $plaintext);
    printf('Ciphertext: %s' . PHP_EOL, $encryptResponse->getCiphertext());
    return $encryptResponse;
}

Python

To run this code, first set up a Python development environment and install the Cloud KMS Python SDK.

def encrypt_symmetric(project_id, location_id, key_ring_id, key_id, plaintext):
    """
    Encrypt plaintext using a symmetric 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').
        plaintext (string): message to encrypt

    Returns:
        bytes: Encrypted ciphertext.

    """

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

    # Import base64 for printing the ciphertext.
    import base64

    # Convert the plaintext to bytes.
    plaintext_bytes = plaintext.encode('utf-8')

    # Optional, but recommended: compute plaintext's CRC32C.
    # See crc32c() function defined below.
    plaintext_crc32c = crc32c(plaintext_bytes)

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

    # Build the key name.
    key_name = client.crypto_key_path(project_id, location_id, key_ring_id, key_id)

    # Call the API.
    encrypt_response = client.encrypt(
      request={'name': key_name, 'plaintext': plaintext_bytes, 'plaintext_crc32c': plaintext_crc32c})

    # Optional, but recommended: perform integrity verification on encrypt_response.
    # 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 encrypt_response.verified_plaintext_crc32c:
        raise Exception('The request sent to the server was corrupted in-transit.')
    if not encrypt_response.ciphertext_crc32c == crc32c(encrypt_response.ciphertext):
        raise Exception('The response received from the server was corrupted in-transit.')
    # End integrity verification

    print('Ciphertext: {}'.format(base64.b64encode(encrypt_response.ciphertext)))
    return encrypt_response


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

To run this code, first set up a Ruby development environment and install the 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"
# plaintext  = "..."

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

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

# Build the parent key name.
key_name = client.crypto_key_path project:    project_id,
                                  location:   location_id,
                                  key_ring:   key_ring_id,
                                  crypto_key: key_id

# Call the API.
response = client.encrypt name: key_name, plaintext: plaintext
puts "Ciphertext: #{Base64.strict_encode64 response.ciphertext}"

API

These examples use curl as an HTTP client to demonstrate using the API. For more information about access control, see Accessing the Cloud KMS API.

When using JSON and the REST API, content must be base-64 encoded before it can be encrypted by Cloud KMS.

To encrypt data, make a POST request and provide the appropriate project and key information and specify the base64-encoded text to be encrypted in the plaintext field of the request body.

curl "https://cloudkms.googleapis.com/v1/projects/project-id/locations/location/keyRings/key-ring-name/cryptoKeys/key-name:encrypt" \
  --request "POST" \
  --header "authorization: Bearer token" \
  --header "content-type: application/json" \
  --data "{\"plaintext\": \"base64-encoded-input\"}"

Here is an example payload with base64-encoded data:

{
  "plaintext": "U3VwZXIgc2VjcmV0IHRleHQgdGhhdCBtdXN0IGJlIGVuY3J5cHRlZAo=",
}

Disable or schedule destruction of the prior key version

If you rotated your key in response to a suspected incident, after you have re-encrypted the data, disable or schedule destruction of the prior key version.

Disable an enabled key version

Only a key version which is Enabled can be Disabled. This is done with the method UpdateCryptoKeyVersion.

Web UI

  1. Go to the Cryptographic Keys page in the Cloud Console.

    Go to the Cryptographic Keys page

  2. Click the name of the key ring that contains the key whose key version you will disable.

  3. Click the key whose key version you want to disable.

  4. Check the box next to the key version(s) that you want to disable.

  5. Click Disable in the header.

  6. In the confirmation prompt, click Disable.

Command-line

To use Cloud KMS on the command line, first Install or upgrade to the latest version of Cloud SDK.

gcloud kms keys versions disable key-version \
    --key key \
    --keyring key-ring \
    --location location

Replace key-version with the version of the key to disable. Replace key with the name of the key. Replace key-ring with the name of the key ring where the key is located. Replace location with the Cloud KMS location for the key ring.

For information on all flags and possible values, run the command with the --help flag.

C#

To run this code, first set up a C# development environment and install the Cloud KMS C# SDK.


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

public class DisableKeyVersionSample
{
    public CryptoKeyVersion DisableKeyVersion(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.
        CryptoKeyVersion keyVersion = new CryptoKeyVersion
        {
            CryptoKeyVersionName = new CryptoKeyVersionName(projectId, locationId, keyRingId, keyId, keyVersionId),
            State = CryptoKeyVersion.Types.CryptoKeyVersionState.Disabled,
        };

        // Build the update mask.
        FieldMask fieldMask = new FieldMask
        {
            Paths = { "state" },
        };

        // Call the API.
        CryptoKeyVersion result = client.UpdateCryptoKeyVersion(keyVersion, fieldMask);

        // Return the result.
        return result;
    }
}

Go

To run this code, first set up a Go development environment and install the Cloud KMS Go SDK.

import (
	"context"
	"fmt"
	"io"

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

// disableKeyVersion disables the specified key version on Cloud KMS.
func disableKeyVersion(w io.Writer, name string) error {
	// parent := "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)
	}

	// Build the request.
	req := &kmspb.UpdateCryptoKeyVersionRequest{
		CryptoKeyVersion: &kmspb.CryptoKeyVersion{
			Name:  name,
			State: kmspb.CryptoKeyVersion_DISABLED,
		},
		UpdateMask: &fieldmask.FieldMask{
			Paths: []string{"state"},
		},
	}

	// Call the API.
	result, err := client.UpdateCryptoKeyVersion(ctx, req)
	if err != nil {
		return fmt.Errorf("failed to update key version: %v", err)
	}
	fmt.Fprintf(w, "Disabled key version: %s\n", result)
	return nil
}

Java

To run this code, first set up a Java development environment and install the Cloud KMS Java SDK.

import com.google.cloud.kms.v1.CryptoKeyVersion;
import com.google.cloud.kms.v1.CryptoKeyVersion.CryptoKeyVersionState;
import com.google.cloud.kms.v1.CryptoKeyVersionName;
import com.google.cloud.kms.v1.KeyManagementServiceClient;
import com.google.protobuf.FieldMask;
import com.google.protobuf.util.FieldMaskUtil;
import java.io.IOException;

public class DisableKeyVersion {

  public void disableKeyVersion() 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";
    disableKeyVersion(projectId, locationId, keyRingId, keyId, keyVersionId);
  }

  // Disable a key version from use.
  public void disableKeyVersion(
      String projectId, String locationId, String keyRingId, String keyId, String keyVersionId)
      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);

      // Build the updated key version, setting it to disbaled.
      CryptoKeyVersion keyVersion =
          CryptoKeyVersion.newBuilder()
              .setName(keyVersionName.toString())
              .setState(CryptoKeyVersionState.DISABLED)
              .build();

      // Create a field mask of updated values.
      FieldMask fieldMask = FieldMaskUtil.fromString("state");

      // Destroy the key version.
      CryptoKeyVersion response = client.updateCryptoKeyVersion(keyVersion, fieldMask);
      System.out.printf("Disabled key version: %s%n", response.getName());
    }
  }
}

Node.js

To run this code, first set up a Node.js development environment and install the Cloud KMS Node.js SDK.

//
// 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';
// const versionId = '123';

// 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 disableKeyVersion() {
  const [version] = await client.updateCryptoKeyVersion({
    cryptoKeyVersion: {
      name: versionName,
      state: 'DISABLED',
    },
    updateMask: {
      paths: ['state'],
    },
  });

  console.log(`Disabled key version: ${version.name}`);
  return version;
}

return disableKeyVersion();

PHP

To run this code, first learn about using PHP on Google Cloud and install the Cloud KMS PHP SDK.

use Google\Cloud\Kms\V1\CryptoKeyVersion;
use Google\Cloud\Kms\V1\CryptoKeyVersion\CryptoKeyVersionState;
use Google\Cloud\Kms\V1\KeyManagementServiceClient;
use Google\Protobuf\FieldMask;

function disable_key_version_sample(
    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);

    // Create the updated version.
    $keyVersion = (new CryptoKeyVersion())
        ->setName($keyVersionName)
        ->setState(CryptoKeyVersionState::DISABLED);

    // Create the field mask.
    $updateMask = (new FieldMask())
        ->setPaths(['state']);

    // Call the API.
    $disabledVersion = $client->updateCryptoKeyVersion($keyVersion, $updateMask);
    printf('Disabled key version: %s' . PHP_EOL, $disabledVersion->getName());
    return $disabledVersion;
}

Python

To run this code, first set up a Python development environment and install the Cloud KMS Python SDK.

def disable_key_version(project_id, location_id, key_ring_id, key_id, version_id):
    """
    Disable a 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 version to disable (e.g. '1').

    Returns:
        CryptoKeyVersion: The version.

    """

    # 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)

    key_version = {
        'name': key_version_name,
        'state': kms.CryptoKeyVersion.CryptoKeyVersionState.DISABLED
    }

    # Build the update mask.
    update_mask = {'paths': ['state']}

    # Call the API.
    disabled_version = client.update_crypto_key_version(request={'crypto_key_version': key_version, 'update_mask': update_mask})
    print('Disabled key version: {}'.format(disabled_version.name))
    return disabled_version

Ruby

To run this code, first set up a Ruby development environment and install the 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"

# 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

# Create the updated version.
version = {
  name:  key_version_name,
  state: :DISABLED
}

# Create the field mask.
update_mask = { paths: ["state"] }

# Call the API.
disabled_version = client.update_crypto_key_version crypto_key_version: version, update_mask: update_mask
puts "Disabled key version: #{disabled_version.name}"

Schedule a key version for destruction

Only key versions which are Enabled or Disabled can be Scheduled for destruction. This is done with the method DestroyCryptoKeyVersion.

Web UI

  1. Go to the Cryptographic Keys page in the Cloud Console.

    Go to the Cryptographic Keys page

  2. Click the name of the key ring that contains the key whose key version you will schedule for destruction.

  3. Click the key whose key version you want to schedule for destruction.

  4. Check the box next to the key version that you want to schedule for destruction.

  5. Click Destroy in the header.

  6. In the confirmation prompt, enter the key name and then click Schedule Destruction.

Command-line

To use Cloud KMS on the command line, first Install or upgrade to the latest version of Cloud SDK.

gcloud kms keys versions destroy key-version \
    --key key \
    --keyring key-ring \
    --location location

Replace key-version with the version of the key to destroy. Replace key with the name of the key. Replace key-ring with the name of the key ring where the key iis located. Replace location with the Cloud KMS location for the key ring.

For information on all flags and possible values, run the command with the --help flag.

C#

To run this code, first set up a C# development environment and install the Cloud KMS C# SDK.


using Google.Cloud.Kms.V1;

public class DestroyKeyVersionSample
{
    public CryptoKeyVersion DestroyKeyVersion(
      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.
        CryptoKeyVersion result = client.DestroyCryptoKeyVersion(keyVersionName);

        // Return the result.
        return result;
    }
}

Go

To run this code, first set up a Go development environment and install the Cloud KMS Go SDK.

import (
	"context"
	"fmt"
	"io"

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

// destroyKeyVersion marks a specified key version for deletion. The key can be
// restored if requested within 24 hours.
func destroyKeyVersion(w io.Writer, name string) error {
	// parent := "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)
	}

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

	// Call the API.
	result, err := client.DestroyCryptoKeyVersion(ctx, req)
	if err != nil {
		return fmt.Errorf("failed to destroy key version: %v", err)
	}
	fmt.Fprintf(w, "Destroyed key version: %s\n", result)
	return nil
}

Java

To run this code, first set up a Java development environment and install the Cloud KMS Java SDK.

import com.google.cloud.kms.v1.CryptoKeyVersion;
import com.google.cloud.kms.v1.CryptoKeyVersionName;
import com.google.cloud.kms.v1.KeyManagementServiceClient;
import java.io.IOException;

public class DestroyKeyVersion {

  public void destroyKeyVersion() 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";
    destroyKeyVersion(projectId, locationId, keyRingId, keyId, keyVersionId);
  }

  // Schedule destruction of the given key version.
  public void destroyKeyVersion(
      String projectId, String locationId, String keyRingId, String keyId, String keyVersionId)
      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);

      // Destroy the key version.
      CryptoKeyVersion response = client.destroyCryptoKeyVersion(keyVersionName);
      System.out.printf("Destroyed key version: %s%n", response.getName());
    }
  }
}

Node.js

To run this code, first set up a Node.js development environment and install the Cloud KMS Node.js SDK.

//
// 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';
// const versionId = '123';

// 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 destroyKeyVersion() {
  const [version] = await client.destroyCryptoKeyVersion({
    name: versionName,
  });

  console.log(`Destroyed key version: ${version.name}`);
  return version;
}

return destroyKeyVersion();

PHP

To run this code, first learn about using PHP on Google Cloud and install the Cloud KMS PHP SDK.

use Google\Cloud\Kms\V1\KeyManagementServiceClient;

function destroy_key_version_sample(
    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.
    $destroyedVersion = $client->destroyCryptoKeyVersion($keyVersionName);
    printf('Destroyed key version: %s' . PHP_EOL, $destroyedVersion->getName());
    return $destroyedVersion;
}

Python

To run this code, first set up a Python development environment and install the Cloud KMS Python SDK.

def destroy_key_version(project_id, location_id, key_ring_id, key_id, version_id):
    """
    Schedule destruction of the given key version.

    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 version to destroy (e.g. '1').

    Returns:
        CryptoKeyVersion: The version.

    """

    # 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.
    destroyed_version = client.destroy_crypto_key_version(request={'name': key_version_name})
    print('Destroyed key version: {}'.format(destroyed_version.name))
    return destroyed_version

Ruby

To run this code, first set up a Ruby development environment and install the 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"

# 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.
destroyed_version = client.destroy_crypto_key_version name: key_version_name
puts "Destroyed key version: #{destroyed_version.name}"