Tink memungkinkan Anda melakukan enkripsi sisi klien terhadap beberapa data, dan untuk melindungi menggunakan Cloud Key Management System (KMS). Cara kerjanya adalah sebagai berikut:
- Klien membuat Kunci Enkripsi Data (DEK).
- Data dienkripsi menggunakan DEK oleh klien.
- DEK dienkripsi oleh Kunci Enkripsi Kunci (KEK) yang disimpan di cloud KMS.
Dengan menggunakan Cloud KMS, KEK Anda tersimpan dengan aman di cloud, sehingga Anda dapat merotasi, menonaktifkan, atau menghancurkannya, tergantung pada kebutuhan Anda.
Lihat bagian ringkasan pengelolaan kunci untuk informasi selengkapnya informasi tentang apa yang diperlukan Tink untuk berinteraksi dengan Cloud KMS.
Dengan Tink, Anda dapat melakukan enkripsi sisi klien dengan Cloud KMS melalui dua cara:
Menggunakan primitif AEAD amplop KMS (
KmsEnvelopeAead) – Untuk setiap enkripsi, Tink membuat AEAD DEK baru, mengenkripsinya dengan Cloud KMS KEK, dan menyimpannya sebagai bagian dari teks tersandi, sehingga Anda tidak perlu menangani DEK diri Anda sendiri. Akibatnya, teks tersandi sedikit lebih panjang karena menyertakan DEK terenkripsi. Selain itu, setiap kali Anda mengenkripsi atau mendekripsi, Tink membuat RPC ke KMS (dekripsi atau enkripsi aktual dari data berjalan secara lokal).Menggunakan primitif lain dan mengenkripsi keyset dengan cloud KMS – Opsi ini lebih fleksibel dalam hal Anda dapat menggunakan primitif yang berbeda selain AEAD, dan Anda dapat membatasi dan panggilan ke Cloud KMS.
AEAD amplop KMS
Saat Anda mengenkripsi data dengan primitif KmsEnvelopeAead, Tink melakukan
berikut ini untuk Anda:
- Menghasilkan DEK acak dan mengenkripsi data Anda secara lokal dengan DEK tersebut.
- Membuat permintaan ke KMS Anda untuk mengenkripsi DEK dengan KMS KEK.
- Menggabungkan DEK enkripsi terenkripsi KEK dengan data terenkripsi.
Baik jenis DEK maupun URI KEK ditetapkan di kunci KmsEnvelopeAead.
Saat mendekripsi, Tink melakukan operasi terbalik:
- Mengekstrak kunci DEK yang dienkripsi KEK.
- Membuat permintaan ke KMS Anda untuk mendekripsi DEK yang dienkripsi KEK.
- Mendekripsi teks tersandi secara lokal menggunakan DEK.
Contoh berikut menunjukkan cara menggunakan primitif KmsEnvelopeAead.
C++
Untuk contoh ini, Anda memerlukan ekstensi Google Cloud KMS
tink-cc-gcpkms
// A command-line utility for testing Tink Envelope AEAD with Google Cloud KMS.
#include <fstream>
#include <iostream>
#include <memory>
#include <ostream>
#include <sstream>
#include <string>
#include <utility>
#include "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/log/check.h"
#include "absl/log/log.h"
#include "absl/status/status.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include "tink/aead.h"
#include "tink/aead/aead_config.h"
#include "tink/aead/aead_key_templates.h"
#include "tink/aead/kms_envelope_aead.h"
#include "tink/integration/gcpkms/gcp_kms_client.h"
#include "tink/util/status.h"
#include "tink/util/statusor.h"
#include "proto/tink.pb.h"
ABSL_FLAG(std::string, mode, "", "Mode of operation {encrypt|decrypt}");
ABSL_FLAG(std::string, kek_uri, "", "URI of the KMS Key Encryption Key to use");
ABSL_FLAG(std::string, input_filename, "", "Input file name");
ABSL_FLAG(std::string, output_filename, "", "Output file name");
ABSL_FLAG(std::string, credentials, "",
"Optional Google Cloud KMS credentials file path; if not specified, "
"use the default credentials");
ABSL_FLAG(std::string, associated_data, "", "Optional associated data");
namespace {
using ::crypto::tink::Aead;
using ::crypto::tink::AeadKeyTemplates;
using ::crypto::tink::integration::gcpkms::GcpKmsClient;
using ::crypto::tink::util::Status;
using ::crypto::tink::util::StatusOr;
using ::google::crypto::tink::KeyTemplate;
constexpr absl::string_view kEncrypt = "encrypt";
constexpr absl::string_view kDecrypt = "decrypt";
void ValidateParams() {
// ...
}
absl::StatusOr<std::string> ReadFile(absl::string_view filename) {
// ...
}
absl::Status WriteToFile(absl::string_view data_to_write,
absl::string_view filename) {
// ...
}
} // namespace
namespace tink_cc_gcpkms_examples {
void KmsEnvelopAeadCli(absl::string_view mode, absl::string_view kek_uri,
absl::string_view input_filename,
absl::string_view output_filename,
absl::string_view credentials,
absl::string_view associated_data) {
CHECK_OK(crypto::tink::AeadConfig::Register());
// Obtain a remote Aead that can use the KEK.
StatusOr<std::unique_ptr<GcpKmsClient>> gcp_kms_client =
GcpKmsClient::New(kek_uri, credentials);
CHECK_OK(gcp_kms_client.status());
StatusOr<std::unique_ptr<Aead>> remote_aead =
(*gcp_kms_client)->GetAead(kek_uri);
CHECK_OK(remote_aead.status());
// Define the DEK template.
KeyTemplate dek_key_template = AeadKeyTemplates::Aes256Gcm();
// Create a KmsEnvelopeAead instance.
StatusOr<std::unique_ptr<Aead>> aead = crypto::tink::KmsEnvelopeAead::New(
dek_key_template, *std::move(remote_aead));
CHECK_OK(aead.status());
StatusOr<std::string> input_file_content = ReadFile(input_filename);
CHECK_OK(input_file_content.status());
if (mode == kEncrypt) {
// Generate the ciphertext.
StatusOr<std::string> encrypt_result =
(*aead)->Encrypt(*input_file_content, associated_data);
CHECK_OK(encrypt_result.status());
CHECK_OK(WriteToFile(encrypt_result.value(), output_filename));
} else { // mode == kDecrypt.
// Recover the plaintext.
StatusOr<std::string> decrypt_result =
(*aead)->Decrypt(*input_file_content, associated_data);
CHECK_OK(decrypt_result.status());
CHECK_OK(WriteToFile(decrypt_result.value(), output_filename));
}
}
} // namespace tink_cc_gcpkms_examples
int main(int argc, char** argv) {
absl::ParseCommandLine(argc, argv);
ValidateParams();
std::string mode = absl::GetFlag(FLAGS_mode);
std::string kek_uri = absl::GetFlag(FLAGS_kek_uri);
std::string input_filename = absl::GetFlag(FLAGS_input_filename);
std::string output_filename = absl::GetFlag(FLAGS_output_filename);
std::string credentials = absl::GetFlag(FLAGS_credentials);
std::string associated_data = absl::GetFlag(FLAGS_associated_data);
LOG(INFO) << "Using kek-uri " << kek_uri << " with "
<< (credentials.empty()
? "default credentials"
: absl::StrCat("credentials file ", credentials))
<< " to envelope " << mode << " file " << input_filename
<< " with associated data '" << associated_data << "'." << '\n';
LOG(INFO) << "The resulting output will be written to " << output_filename
<< '\n';
tink_cc_gcpkms_examples::KmsEnvelopAeadCli(mode, kek_uri, input_filename,
output_filename, credentials,
associated_data);
return 0;
}
Go
import (
"fmt"
"log"
"github.com/tink-crypto/tink-go/v2/aead"
"github.com/tink-crypto/tink-go/v2/testing/fakekms"
)
// The fake KMS should only be used in tests. It is not secure.
const keyURI = "fake-kms://CM2b3_MDElQKSAowdHlwZS5nb29nbGVhcGlzLmNvbS9nb29nbGUuY3J5cHRvLnRpbmsuQWVzR2NtS2V5EhIaEIK75t5L-adlUwVhWvRuWUwYARABGM2b3_MDIAE"
func Example_kmsEnvelopeAEAD() {
// Get a KEK (key encryption key) AEAD. This is usually a remote AEAD to a KMS. In this example,
// we use a fake KMS to avoid making RPCs.
client, err := fakekms.NewClient(keyURI)
if err != nil {
log.Fatal(err)
}
kekAEAD, err := client.GetAEAD(keyURI)
if err != nil {
log.Fatal(err)
}
// Get the KMS envelope AEAD primitive.
primitive := aead.NewKMSEnvelopeAEAD2(aead.AES256GCMKeyTemplate(), kekAEAD)
// Use the primitive.
plaintext := []byte("message")
associatedData := []byte("example KMS envelope AEAD encryption")
ciphertext, err := primitive.Encrypt(plaintext, associatedData)
if err != nil {
log.Fatal(err)
}
decrypted, err := primitive.Decrypt(ciphertext, associatedData)
if err != nil {
log.Fatal(err)
}
fmt.Println(string(decrypted))
// Output: message
}
Java
Untuk contoh ini, Anda memerlukan ekstensi Google Cloud KMS
tink-java-gcpkms
package envelopeaead;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.crypto.tink.Aead;
import com.google.crypto.tink.KmsClient;
import com.google.crypto.tink.aead.AeadConfig;
import com.google.crypto.tink.aead.KmsEnvelopeAead;
import com.google.crypto.tink.aead.PredefinedAeadParameters;
import com.google.crypto.tink.integration.gcpkms.GcpKmsClient;
import java.io.File;
import java.io.FileOutputStream;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.GeneralSecurityException;
/**
* A command-line utility for encrypting small files with envelope encryption.
*
* <p>It requires the following arguments:
*
* <ul>
* <li>mode: Can be "encrypt" or "decrypt" to encrypt/decrypt the input to the output.
* <li>kek-uri: Use this Cloud KMS' key as the key-encrypting-key for envelope encryption.
* <li>gcp-credential-file: Use this JSON credential file to connect to Cloud KMS.
* <li>input-file: Read the input from this file.
* <li>output-file: Write the result to this file.
* <li>[optional] associated-data: Associated data used for the encryption or decryption.
*/
public final class EnvelopeAeadExample {
private static final String MODE_ENCRYPT = "encrypt";
private static final String MODE_DECRYPT = "decrypt";
public static void main(String[] args) throws Exception {
if (args.length != 5 && args.length != 6) {
System.err.printf("Expected 5 or 6 parameters, got %d\n", args.length);
System.err.println(
"Usage: java EnvelopeAeadExample encrypt/decrypt kek-uri gcp-credential-file"
+ " input-file output-file [associated-data]");
System.exit(1);
}
String mode = args[0];
String kekUri = args[1];
String gcpCredentialFilename = args[2];
byte[] input = Files.readAllBytes(Paths.get(args[3]));
File outputFile = new File(args[4]);
byte[] associatedData = new byte[0];
if (args.length == 6) {
System.out.println("Associated data!");
associatedData = args[5].getBytes(UTF_8);
}
// Initialise Tink: register all AEAD key types with the Tink runtime
AeadConfig.register();
// Read the GCP credentials and create a remote AEAD object.
Aead remoteAead = null;
try {
KmsClient kmsClient = new GcpKmsClient().withCredentials(gcpCredentialFilename);
remoteAead = kmsClient.getAead(kekUri);
} catch (GeneralSecurityException ex) {
System.err.println("Error initializing GCP client: " + ex);
System.exit(1);
}
// Create envelope AEAD primitive using AES256 GCM for encrypting the data
Aead aead = KmsEnvelopeAead.create(PredefinedAeadParameters.AES256_GCM, remoteAead);
// Use the primitive to encrypt/decrypt files.
if (MODE_ENCRYPT.equals(mode)) {
byte[] ciphertext = aead.encrypt(input, associatedData);
try (FileOutputStream stream = new FileOutputStream(outputFile)) {
stream.write(ciphertext);
}
} else if (MODE_DECRYPT.equals(mode)) {
byte[] plaintext = aead.decrypt(input, associatedData);
try (FileOutputStream stream = new FileOutputStream(outputFile)) {
stream.write(plaintext);
}
} else {
System.err.println("The first argument must be either encrypt or decrypt, got: " + mode);
System.exit(1);
}
System.exit(0);
}
private EnvelopeAeadExample() {}
}
Python
"""A command-line utility for encrypting small files using envelope encryption with GCP."""
from absl import app
from absl import flags
from absl import logging
import tink
from tink import aead
from tink.integration import gcpkms
FLAGS = flags.FLAGS
flags.DEFINE_enum(
'mode', None, ['encrypt', 'decrypt'], 'The operation to perform.'
)
flags.DEFINE_string(
'kek_uri', None, 'The Cloud KMS URI of the key encryption key.'
)
flags.DEFINE_string(
'gcp_credential_path', None, 'Path to the GCP credentials JSON file.'
)
flags.DEFINE_string('input_path', None, 'Path to the input file.')
flags.DEFINE_string('output_path', None, 'Path to the output file.')
flags.DEFINE_string(
'associated_data', None, 'Optional associated data used for the encryption.'
)
def main(argv):
del argv # Unused.
associated_data = (
b''
if not FLAGS.associated_data
else bytes(FLAGS.associated_data, 'utf-8')
)
# Initialise Tink
aead.register()
try:
# Read the GCP credentials and setup client
client = gcpkms.GcpKmsClient(FLAGS.kek_uri, FLAGS.gcp_credential_path)
except tink.TinkError as e:
logging.exception('Error creating GCP KMS client: %s', e)
return 1
# Create envelope AEAD primitive using AES256 GCM for encrypting the data
try:
remote_aead = client.get_aead(FLAGS.kek_uri)
env_aead = aead.KmsEnvelopeAead(
aead.aead_key_templates.AES256_GCM, remote_aead
)
except tink.TinkError as e:
logging.exception('Error creating primitive: %s', e)
return 1
with open(FLAGS.input_path, 'rb') as input_file:
input_data = input_file.read()
if FLAGS.mode == 'decrypt':
output_data = env_aead.decrypt(input_data, associated_data)
elif FLAGS.mode == 'encrypt':
output_data = env_aead.encrypt(input_data, associated_data)
else:
logging.error(
'Unsupported mode %s. Please choose "encrypt" or "decrypt".',
FLAGS.mode,
)
return 1
with open(FLAGS.output_path, 'wb') as output_file:
output_file.write(output_data)
if __name__ == '__main__':
flags.mark_flags_as_required(
['mode', 'kek_uri', 'gcp_credential_path', 'input_path', 'output_path']
)
app.run(main)
Langkah berikutnya
Anda dapat menggunakan enkripsi sisi klien untuk mengenkripsi data sebelum menambahkannya ke Cloud SQL di database.
Pelajari lebih lanjut cara menggunakan enkripsi sisi klien dengan Tink dan Cloud KMS untuk mengenkripsi sebelum menguploadnya ke Google Cloud Storage.